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ImmunoGen
Annual Report 2014

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FY2014 Annual Report · ImmunoGen
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Dear Fellow Shareholders,  

We believe the coming year will be a defining 

one for ImmunoGen. During this period, we 
expect the development path for our lead 
compounds to come into focus, important new 
Kadcyla data to be reported, and the significance 
of other of our partnerships to become 
more pronounced.  

These expectations are underpinned by our 

proven antibody-drug conjugate (ADC) expertise 
and our commitment to developing new and 
better treatments for people with cancer. 

IMGN853 – Now in Initial Efficacy Testing  

We created IMGN853 with the goal of 

helping patients with cancers that highly express 
folate receptor alpha. These include many 
ovarian and endometrial cancers.  

IMGN853 demonstrated evidence of activity 
against both of these cancers in clinical research 
designed to establish its dose. This summer, we 
began the initial assessment of IMGN853 for 
efficacy as well as safety in the treatment of 
platinum-resistant ovarian cancer and previously 
treated endometrial cancer.  

New and better therapies are needed for 
these cancers. Ovarian cancer often is diagnosed 
only after it has spread, limiting the utility of 
surgery and increasing the need for effective 
medicinal options. Endometrial cancer is more 
likely to be diagnosed at a stage where it can still 
be effectively treated, but there are few 
therapeutic options for patients diagnosed with 
advanced disease.  

In the clinical testing underway, patients 
receive IMGN853 once every three weeks. Our 
research indicates that dosing IMGN853 more 
frequently could be beneficial, and therefore we 
are also evaluating a weekly dosing regimen.  
We expect to use the efficacy, safety, and 
dosing information being developed to make key 
decisions for IMGN853 in 2015. 

IMGN289 – Unique EGFR-Targeting Approach 

The epidermal growth factor receptor (EGFR) 

is highly expressed on a number of cancers that 
currently have limited treatment options, 
including many head and neck and non-small cell 
lung cancers (NSCLCs).  

We created IMGN289 with the goal of 

providing better treatment for people with such 
cancers. As with all of our ADCs, IMGN289 is 
designed to bind specifically to its target on 
cancer cells and release its potent cell-killing 
agent – its payload – to kill these cells. In 
preclinical testing, the antibody component of 
IMGN289 also demonstrated meaningful 
anticancer activity against EGFR-sensitive tumors, 
further enhancing activity in such cases. 

We advanced IMGN289 into the clinic in late 
2013 and are currently establishing the dose for 
use in more advanced testing. Next, we plan to 
evaluate its efficacy and safety specifically in the 
treatment of squamous cell head and neck cancer 
and of squamous and non-squamous cell NSCLCs. 
As with IMGN853, we expect to have the 
data needed to make key development decisions 
for IMGN289 in 2015.  

IMGN529 – Promising for B-Cell Malignancies 

Today, non-Hodgkin lymphoma (NHL) is 

often treated with an antibody, Rituxan® 
(rituximab), plus chemotherapy. While many 
patients benefit from this regimen, additional 
treatment options are needed, especially for 
people whose cancer progresses or who cannot 
tolerate aggressive chemotherapy. 

We designed our IMGN529 ADC to help 
address such needs. It, too, contains an antibody 
that preclinically demonstrated meaningful 
anticancer effects. In fact, in some models, its 
antibody was more active than Rituxan. 
In initial clinical testing, IMGN529 

demonstrated evidence of activity at much lower 
doses than other ADCs with our technology, with 
dose escalation ongoing. 

Once we establish the best dose to take 
forward, we plan to assess IMGN529 in disease-
specific patient populations. We expect this 
assessment to be underway in 2015. 

Preparing for Success 

We intend to follow the disease-specific 

testing of our ADCs with more advanced, 
registration-enabling studies, and have been 
building out our team accordingly. In late 2012 
we brought in a Chief Development Officer to 
ensure our development-related functions, 
including Clinical and Regulatory, are 

appropriately staffed and working together 
to strategically and expeditiously advance 
our pipeline.  

We recently hired Sandra Poole, formerly 

head of global biologics manufacturing at 
Genzyme, to similarly ensure our manufacturing-
related functions are appropriately staffed and 
working together to furnish the pivotal materials 
we will need to support advanced trials.  

Earlier this year, we hired a Chief Financial 

Officer with fifteen years of experience in senior 
financial positions at later-stage biotech 
companies, as well as a Vice President of Product 
Strategy and Program Management – a position 
created to ensure our product programs align 
with patient needs.  

We also added a Chief Human Resources 

Officer in light of the increasing size and 
complexity of the ImmunoGen workforce as we 
advance to next stages. 

Commitment to ADC Leadership  

While the goal of each ADC program is the 
same – to provide better efficacy and tolerability 
than currently available therapies – they differ in 
their targets and thus in their designs.  

Our unique depth of ADC expertise has 
enabled us to employ a wealth of approaches to 
antibody selection and to develop a robust 
portfolio of engineered linkers and payload 
agents to create the best ADC for the purpose.  

For example, the antibody we developed for 

IMGN289 was not – in preclinical testing –
associated with the skin toxicity seen with 
marketed anti-EGFR antibodies, and the linker in 
IMGN853 was designed by our scientists to 
counter the multi-drug resistance that many 
tumors develop. 

We are committed to retaining our ADC 
leadership. In the past year, we reported data on 
two additional novel linkers and a new family of 
payload agents that we developed to continue to 
extend the utility of ADC therapies. One of these 
payload agents is used in IMGN779, which is 
expected to be our next clinical-stage compound.  
Additionally, we established a collaboration 

with CytomX that provides us with defined rights 
to use their proprietary antibody masking 
technology to create ADCs. This should 
enhance our ability to more precisely target 
diseased tissue.  

Wealth of Partnerships with Leading Healthcare 
Companies 

There are numerous ADC therapies in the 

clinic today through our partnerships, with 
several more expected to enter human testing in 
the coming year.  

The most advanced, Roche’s Kadcyla® (ado-

trastuzumab emtansine), is the only ADC to 
demonstrate a survival benefit in a randomized 
clinical trial and gain full FDA marketing approval.  
Kadcyla has been approved for the treatment 

of HER2-positive metastatic breast cancer (mBC) 
previously treated with Herceptin and a taxane in 
a number of countries around the world and is 
being launched for that use. We are thrilled that 
our technology is now making a difference for 
patients around the world. 

With favorable data, Roche intends to submit 

in 2015 for regulatory approval for two more 
uses – first-line treatment of HER2-positive mBC 
and second-line treatment of advanced HER2-
positive gastric cancer. Roche also has initiated 
three Phase III trials assessing Kadcyla in early 
breast cancer settings. 

In the past year, encouraging clinical data 

were reported for multiple partner compounds, 
including proof of concept data for the three 
now in Phase II testing – BT-062, SAR3419, and 
SAR650984. Another compound entered the 
clinic, and three more licenses were taken by our 
partners. 

All of these activities represent important 

steps forward in bringing new and better 
therapies to people with cancer.  

In Closing 

The coming year should be an exciting one 

for ImmunoGen, and we look forward to 
reporting clinical data and development progress.  

I thank you for your support. 

Sincerely,  

Daniel M. Junius 
President and CEO 
September 16, 2014  

 
 
 
 
UNITED STATES
SECURITIES AND  EXCHANGE  COMMISSION

Washington, D.C. 20549

Form 10-K

(cid:1) ANNUAL REPORT PURSUANT TO  SECTION 13  OR  15(d) OF  THE

SECURITIES EXCHANGE ACT OF 1934

(cid:2)

For the fiscal year ended June 30, 2014
OR

TRANSITION REPORT PURSUANT  TO  SECTION 13  OR  15(d) OF  THE
SECURITIES EXCHANGE ACT OF 1934
For the transition period from 

 to 

Commission file number 0-17999

ImmunoGen, Inc.

Massachusetts
(State or other jurisdiction
of incorporation or organization)

04-2726691
(I.R.S. Employer
Identification No.)

830 Winter Street, Waltham, MA 02451
(Address of principal executive offices, including zip code)

(781) 895-0600
(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class

Name  of Each Exchange on Which Registered

Common Stock, $.01  par value

NASDAQ Global Select Market

Indicate by  check  mark  if  the registrant  is a  well-known seasoned issuer, as defined in Rule 405 of the Securities

Act.  (cid:1) Yes (cid:2) No

Indicate by  check  mark  if  the registrant  is not  required to file reports pursuant to Section 13 or Section 15(d) of the

Act.  (cid:2) Yes (cid:1) No

Indicate by  check  mark  whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the

Securities Exchange  Act of  1934 during the  preceding 12 months (or for such shorter period that the registrant was required to
file  such reports), and (2) has been  subject  to  such  filing requirements for the past 90 days. (cid:1) Yes (cid:2)  No

Indicate by  check mark whether the registrant has submitted electronically and posted on its corporate Website, if any,

every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§229.405 of this
chapter)  during  the preceding 12 months  (or  for  such shorter period that the registrant was required to submit and post such
files). (cid:1) Yes (cid:2)  No

Indicate by  check mark if disclosure  of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter)

is not contained herein, and  will not be  contained,  to the best of registrant’s knowledge, in definitive proxy or information
statements incorporated  by reference  in Part  III  of  this Form 10-K or any amendment to this Form 10-K. (cid:1)

Indicate by  check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a
smaller reporting company. See definitions  of  ‘‘large accelerated filer,’’ ‘‘accelerated filer,’’ and ‘‘smaller reporting company’’ in
Rule  12b-2 of the  Exchange Act. (Check  one):
Large  accelerated filer (cid:1)

Smaller reporting company  (cid:2)

Accelerated filer (cid:2)

Non-accelerated filer  (cid:2)
(Do  not check if  a smaller reporting
company)

Indicate by  check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange

Act). (cid:2)  Yes (cid:1) No

Aggregate market value,  based upon the closing sale price of the shares as reported by the NASDAQ Global Select
Market,  of voting stock held by  non-  affiliates at  December 31, 2013: $1,252,547,383 (excludes shares held by executive officers
and directors).  Exclusion  of shares held  by  any  person should not be construed to indicate that such person possesses the power,
direct or indirect, to direct or cause the  direction  of management or policies of the registrant, or that such person is controlled
by or  under common control with the  registrant.  Common Stock outstanding at August 20, 2014: 85,907,896 shares.

Portions of the definitive  Proxy  Statement to be delivered to shareholders in connection with the Annual Meeting of

Shareholders to be held on  November  11,  2014  are incorporated by reference into Part III.

DOCUMENTS INCORPORATED BY REFERENCE

ImmunoGen, Inc.

Form 10-K

TABLE OF CONTENTS

Item

1.
1A.
1B.
2.
3.
3.1
4.

5.

6.
7.

7A.
8.
9.

9A.
9B.

10.
11.
12.

13.
14.

15.

Part I
Business . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unresolved Staff Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Legal  Proceedings
Executive Officers of the Registrant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mine Safety Disclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Part II

Market for Registrant’s Common Equity, Related Stockholder  Matters and Issuer

Purchases of Equity Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selected Financial Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Management’s Discussion and Analysis of Financial Condition and Results of

Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Quantitative and Qualitative Disclosures About  Market Risk . . . . . . . . . . . . . . . . . . .
Financial Statements and Supplementary Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changes in and Disagreements  with  Accountants on Accounting  and Financial

Disclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controls and Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Part III
Directors, Executive Officers and Corporate Governance . . . . . . . . . . . . . . . . . . . . . .
Executive Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Security Ownership of Certain  Beneficial Owners  and Management  and Related

Stockholder Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Certain Relationships and Related Transactions, and  Director Independence . . . . . . . .
Principal Accounting Fees and  Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Part IV
Exhibits, Financial Statement Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Signatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page
Number

3
27
42
42
42
42
43

44
44

45
60
61

109
109
111

112
112

112
112
112

113

114

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Item 1. Business

In this Annual Report on Form 10-K, ImmunoGen, Inc. (ImmunoGen, Inc.,  together  with its

subsidiaries, is referred to in this document as ‘‘we’’, ‘‘us’’, ‘‘ImmunoGen’’, or the  ‘‘Company’’),
incorporates by reference certain information from  parts of other documents filed with  the Securities
and Exchange Commission. The Securities and Exchange  Commission allows us to disclose important
information by referring to it in that manner.  Please  refer to all such  information when reading this
Annual Report on Form 10-K. All information  is as  of  June  30, 2014 unless otherwise indicated. For a
description of the risk factors affecting or  applicable to our business, see  ‘‘Risk  Factors,’’ below.

Overview

We  are a biotechnology company that develops targeted anticancer therapeutics. All  of our  wholly
owned clinical and preclinical product  candidates are antibody-drug conjugates, or  ADCs. An ADC  is a
type of medicine that uses a monoclonal  antibody to deliver  a  therapeutic agent to targeted cells.

We  developed our ADC technology to enable the creation of highly effective, well-tolerated
anticancer products. An ADC with our technology comprises an antibody that binds specifically to an
antigen target found on the surface of cancer cells with  one  of  our potent cancer-cell  killing agents,  or
payloads, attached  to the antibody using  one of our engineered linkers. An ADC  compound’s antibody
component enables it to bind to cancer  cells that have its antigen on their surface and the payload
agent serves to kill these cancer cells.  We  have tubulin-acting payload agents, such as DM1 and DM4,
which  are maytansinoids, and, more recently, we developed DNA-acting payload agents, such  as
DGN462, which we call IGNs. Our linkers are  engineered to keep  our payload agents securely attached
to the antibody while traveling through  the bloodstream and  then  control its  release and activation
once inside a cancer cell. The antibody  component of  an ADC may serve only as a  targeting  vehicle or
it may also have anticancer activity, depending on the antigen target  and the antibody selected.

We  develop our own product candidates using our ADC  technology. We now have three wholly
owned, clinical-stage anticancer compounds—IMGN853, IMGN289, and IMGN529—and have  reported
preclinical data for IMGN779, which  we  expect to be our next clinical-stage  compound. IMGN779 is
the first ADC with our IGN technology.  We  license to other companies limited rights  to  use our ADC
technology with their antibodies to create products. The most advanced compound with our ADC
technology is Roche’s marketed product,  Kadcyla(cid:4) (ado-trastuzumab emtansine). Kadcyla was first
commercialized in early 2013 and we began earning royalties on Kadcyla  sales at that time. Seven other
ADC compounds and one non-ADC,  or ‘‘naked,’’ antibody product candidate are  in clinical  testing
through our partnerships. Our partnership  agreements entitle us to earn milestone payments with
agreed-upon achievements and, for therapies successfully developed and commercialized,  royalties on
product  sales. Our current partners are: Amgen Inc., Bayer  HealthCare (a subgroup of Bayer AG),
Biotest AG, Eli Lilly and Company, or Lilly, Novartis Institutes for BioMedical Research, Inc., or
Novartis, the Roche Group and Sanofi.  We  also have  a research agreement with CytomX  Therapeutics
that allows each company to develop probody-drug conjugates against a specified  number of  cancer
targets using CytomX’s Probody(cid:5) antibody masking technology with our payload agents and  engineered
linkers.

We  were organized as a Massachusetts corporation in 1981. Our principal offices are located at
830 Winter Street, Waltham, Massachusetts  (MA) 02451, and our telephone number  is 781-895-0600.
We  maintain a website at www.immunogen.com, where certain information about us is available. Please
note that information contained on the  website is  not a part of this document. Our Annual Reports on
Form 10-K, Quarterly Reports on Form 10-Q,  Current Reports  on Form 8-K, and any  amendments to
those reports are available free of charge through the ‘‘Investor Information’’ section of our website as
soon as reasonably practicable after those materials have  been electronically  filed with, or furnished to,
the Securities and Exchange Commission. We have adopted  a  Code of Corporate Conduct that applies

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to all our directors, officers and employees and  a Senior Officer and Financial  Personnel Code  of
Ethics that applies to our senior officers  and  financial personnel.  Our Code of  Corporate Conduct and
Senior Officer and Financial Personnel  Code of Ethics  are available free of charge  through the
‘‘Investor Information’’ section of our website.

Pipeline: Wholly Owned and Partner  Product Candidates

Listed in the tables below are the disclosed compounds  in development through our own  programs

and our collaborations with other companies. All of these compounds  are ADCs with the exception of
SAR650984, which is a therapeutic antibody,  and all of these compounds are in  early clinical testing
(Phase I and/or Phase II) with the exception of Kadcyla,  which is marketed,  and IMGN779, which is in
preclinical testing. Additional earlier-stage compounds are  in development by us and several of  our
partners. The results in early clinical trials  may not be predictive of  results obtained in subsequent
clinical trials and there can be no assurance that any  of our  or our collaborators’ product  candidates,
other than Kadcyla, will advance or will  demonstrate the  level of safety  and efficacy necessary to obtain
regulatory approval.

Compounds Wholly Owned by ImmunoGen

Compound

Lead  Indication(s)

IMGN853 . . . . . . . . . . . . Ovarian cancer, endometrial cancer
IMGN289 . . . . . . . . . . . . Head and neck cancers, non-small cell lung cancers
IMGN529 . . . . . . . . . . . . Non-Hodgkin lymphoma
IMGN779 . . . . . . . . . . . . Acute myeloid leukemia

Target
Folate receptor (cid:1)
EGFR
CD37
CD33

Collaborative Partner Compounds

Compound

Lead Indication(s)

Kadcyla . . . . . . . . Previously treated HER2-positive metastatic  breast  cancer
AMG 172 . . . . . . . Kidney cancer
AMG 595 . . . . . . . Glioblastoma
BAY 94-9343 . . . . Mesothelioma, ovarian cancer
BT-062 . . . . . . . . . Multiple myeloma, breast, bladder cancers
SAR3419 . . . . . . . Diffuse large B-cell lymphoma
SAR650984 . . . . . Multiple myeloma
SAR566658 . . . . .
SAR408701 . . . . .

Solid tumors
Solid tumors

Target

Partner

HER2
CD70

Roche
Amgen
EGFRvIII Amgen
Bayer
Mesothelin
Biotest
CD138
Sanofi
CD19
Sanofi
CD38
Sanofi
CA6
Sanofi
CEACAM5

IMGN853

We  created our IMGN853 product candidate as a treatment for ovarian cancer, endometrial

cancer, and potentially other cancers  that highly express folate receptor (cid:1), or FR(cid:1). This ADC
comprises a FR(cid:1)-binding antibody with our potent DM4 payload agent attached using one of our
engineered linkers.

IMGN853 is currently in Phase I clinical testing. During the initial  dose-finding clinical  research,

IMGN853 was found to be generally  well  tolerated  and to demonstrate evidence of anticancer activity.
In July 2014,  it was granted orphan drug  status for ovarian cancer by the  US FDA.

IMGN853 is now beginning assessment  specifically  for the treatment of FR(cid:1)-positive platinum-
resistant ovarian cancer and relapsed  endometrial cancer.  In this assessment, IMGN853 is being dosed
once every three weeks. ImmunoGen research  has indicated  that dosing IMGN853 more frequently
could further enhance efficacy without  reducing  tolerability,  and dose finding  is now  underway with

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IMGN853 dosed weekly for three weeks  followed by one week without treatment.  ImmunoGen plans  to
select between these two schedules for more  advanced IMGN853 clinical  trials.

IMGN289

Our EGFR-targeting ADC, IMGN289, is a  potential new treatment for cancers that highly express

EGFR. These include squamous cell  carcinoma of the head  and neck, or SCCHN, and types of
non-small cell lung cancer (NSCLC),  including both squamous cell and non-squamous cell NSCLCs.
IMGN289 comprises an ImmunoGen  EGFR-binding antibody with  our DM1 payload agent attached
using one of our engineered linkers. In  preclinical testing, the antibody component of IMGN289 was
found to have meaningful anticancer  activity against EGFR-positive cancer cells sensitive to EGFR
inhibition. In these preclinical studies,  the full product  candidate, inclusive  of  the DM1,  demonstrated
superior activity against these cancers  and also against EFGR-positive cancers  not  sensitive to EGFR
inhibitors. This is attributed to the DM1  being  able  to  kill EGFR-positive cancer  cells  through its
mechanism, interference with tubulin formation, that is independent of the EGFR  pathway.

IMGN289 advanced into clinical testing in late 2013. It is currently in  the dose-finding portion of a

Phase I clinical trial and no clinical data  has been reported.

IMGN529

Our IMGN529 ADC is a potential new treatment for  cancers that highly  express  CD37, such as
non-Hodgkin lymphoma, or NHL, and chronic lymphocytic  leukemia. ImmunoGen scientists have found
the expression profile of CD37 on NHL  subtypes  to  be  similar  to  that of CD20, the  target  of Roche’s
Rituxan(cid:4) (rituximab).

IMGN529 comprises an ImmunoGen  CD37-targeting antibody with our DM1  payload agent
attached using one of our engineered linkers. In  preclinical testing, the antibody  demonstrated notable
anticancer activity that was further enhanced by the  addition of the DM1. IMGN529 is  currently  in the
dose-finding portion of a Phase I clinical trial  assessing it  in patients with  NHL previously treated with
other  anticancer agents. Initial evidence  of  anticancer activity has  been reported with IMGN529.

IMGN779

Preclinical-stage IMGN779 is a potential new treatment for acute myeloid leukemia.  It comprises

an ImmunoGen CD33-targeting antibody with one  of  our DNA-acting payload agent, DGN462,
attached using one of our engineered linkers. We currently intend  to  submit an  Investigational New
Drug, or IND, application for it to the FDA  during the latter half of 2015.

Kadcyla (previously referred to as T-DM1)

Kadcyla is a HER2-targeting ADC that comprises trastuzumab,  which is  the active component of
Roche’s  antibody therapeutic, Herceptin(cid:4) (trastuzumab), with our DM1 payload  agent  attached using
one of our engineered linkers. Roche has  global development and commercialization rights for Kadcyla
under an ADC technology license from us.

Kadcyla was granted marketing approval in February  2013  by the  U.S. Food and Drug

Administration, or FDA, for the treatment of HER2-positive metastatic breast cancer in patients who
previously received Herceptin and a taxane.  It was approved for this use  in Japan and in the European
Union  (EU) in September 2013 and  November 2013, respectively.  In some countries, such as the US,
Kadcyla was able to be launched shortly  after gaining marketing approval.  In other  countries, it  is
necessary to negotiate pricing with governmental authorities prior to launch. For example, Kadcyla was
launched in Japan in April 2014 after such negotiations.

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Roche is developing Kadcyla for a number of additional uses, and currently has Phase III, or

registration, trials underway assessing Kadcyla  as a therapy for patients with:

(cid:127) Metastatic HER2-positive breast cancer  not  previously been treated—Roche is assessing Kadcyla
for this use in its MARIANNE trial. Roche  has announced that it  intends to use MARIANNE
results, if favorable, to apply in 2015 for marketing approval  of Kadcyla for this use.

(cid:127) Early stage HER2-positive breast cancer—Roche has  initiated  three Phase III  trials in this
setting: its KATHERINE trial evaluates Kadcyla for the treatment of patients with residual
invasive disease following pre-operative  therapy;  its  KAITLIN trial  assesses Kadcyla for  adjuvant
use; and its KRISTINE trial evaluates  Kadcyla in  the neoadjuvant setting.

(cid:127) Advanced HER2-positive gastric cancer—Roche is evaluating  Kadcyla for this use in its
GATSBY trial. Roche has announced that it intends  to  use the  results from  GATSBY, if
favorable, to apply in 2015 for marketing  approval for this  use.

Other  Clinical-stage Compounds in Development by Our Partners

In addition to Kadcyla, eight other compounds are in  clinical testing through  our collaborations

with other companies. In alphabetical  order, these are:

(cid:127) AMG 172—This CD70-targeting ADC was created  by Amgen under  a license from ImmunoGen.
It  is currently in Phase I clinical testing for  the treatment  of patients  with clear cell renal cell
carcinoma. To our knowledge, no clinical data has been reported with  AMG 172  to  date.

(cid:127) AMG 595—This EGFRvIII-targeting ADC also was created by Amgen under a license from
ImmunoGen. It is currently in Phase I  clinical testing for the treatment of patients with
glioblastoma and initial evidence of activity has been reported.

(cid:127) BAY 94-9343—This mesothelin-targeting ADC was created by Bayer  under a license from

ImmunoGen. Initial evidence of activity in mesothelioma has  been reported.  BAY  94-9343 is
currently being assessed for the treatment of mesothelioma  and ovarian cancer in early  clinical
trials.

(cid:127) BT-062—This CD138-targeting ADC was created by  Biotest under a  license from ImmunoGen.
We have opt-in rights for co-development and co-commercialization of BT-062 with  Biotest in
the U.S. Encouraging findings with BT-062  in the treatment of multiple myeloma have  been
reported, both with the agent used alone and as part of a combination treatment regimen, and
its development for this cancer is ongoing. The target for  BT-062  also  has been found to occur
on several types of solid tumors, and in early 2014 this ADC  began  clinical testing for the
treatment of triple-negative breast cancer and  metastatic urinary bladder  cancer.

(cid:127) SAR3419—This CD19-targeting ADC was initially created  by  ImmunoGen and licensed to Sanofi
as part of a broad research collaboration. In Phase II clinical testing, SAR3419 showed what was
concluded to be proof-of-concept efficacy as  monotherapy in the treatment  of diffuse large
B-cell lymphoma, a difficult-to-treat lymphoma, in patients whose cancer had  returned  after
treatment with other agents. These findings were  reported  at the  annual meeting  of the
American Society of Clinical Oncology, or ASCO, in  June  2014.

(cid:127) SAR650984—This product candidate is CD38-targeting  therapeutic,  or ‘‘naked’’, antibody initially

created by ImmunoGen and licensed to Sanofi  as part  of a broad research collaboration.
SAR650984 has shown promising activity in early clinical testing  when used alone or  as part  of a
combination regimen to treat patients  with previously treated multiple myeloma. Sanofi  has
begun Phase II testing of SAR650984 for multiple myeloma.

6

(cid:127) SAR566658—This CA6-targeting ADC also was initially  created by ImmunoGen and  licensed to
Sanofi as part of a broad research collaboration. It is currently  in Phase I clinical  testing for the
treatment of CA6-positive solid tumors, such  as ovarian cancer, with  initial evidence of  activity
reported.

(cid:127) SAR408701—This CEACAM5-targeting ADC was initially created  by ImmunoGen  and  licensed
to Sanofi as part of a broad research collaboration. Patient enrollment  has opened  in the first
SAR408701 clinical trial.

Earlier-stage ADCs are in development  through our collaborations  with Amgen, CytomX, Lilly,

Novartis, and Sanofi.

Incidence of Relevant Cancers

Cancer remains a leading cause of death worldwide, and is the  second leading cause of death  in
the U.S.  The American Cancer Society,  or  ACS, estimates  that in 2014  approximately 1.7 million  new
cases of cancer will be diagnosed in the  U.S.  and  that approximately 586,000 people will die  from the
disease. The total number of people  living with  cancer significantly exceeds the number of patients
diagnosed with cancer in a given year  as  patients can live with  cancer for  a year or longer. Additionally,
the potential market for anticancer drugs  exceeds the number  of  patients treated as  many types of
cancer typically are treated with multiple compounds at the same time and because patients often
receive a number of drug regimens sequentially.

Below is information about incidence  of cancers  we are  seeking to treat with  our  wholly owned
compounds. In our clinical testing, we  will define treatment subgroups of patients  for the  cancer types
referenced.

IMGN853—Our IMGN853 compound is  a potential treatment  for  epithelial ovarian cancer,

endometrial cancer and potentially other cancers that highly express its target, FR(cid:1). Based on
published sources, we believe approximately 22,000 new  cases of ovarian cancer will be diagnosed in
the US in 2014 and epithelial ovarian  cancer  accounts for  approximately 85% to 90% of these ovarian
cancer cases. We believe that approximately 52,600 cases  of  endometrial cancers will be diagnosed in
the US in 2014.

IMGN289—Our IMGN289 compound  is a  potential treatment  for  many cases of head  and neck
cancer and types of NSCLC. The ACS estimates  that approximately 55,000 new cases of head  and neck
cancers will be diagnosed in 2014. Research conducted  at ImmunoGen found that over  90% of these
types of cancer strongly express EGFR. Based  on ACS estimates, we believe approximately 191,000 new
cases of NSCLC will be diagnosed in the  U.S.  in 2014.  This figure comprises three main subtypes—
adenocarcinoma, squamous cell carcinoma, and large  cell  carcinoma. These subtypes account  for
approximately 40%, 25-30%, and 10-15% of NSCLC diagnoses, respectively. Research with tumor
samples conducted at ImmunoGen found that approximately 20% of adenocarcinoma cases  and about
half of squamous and of large cell carcinoma cases strongly express EGFR.

IMGN529—We are assessing our IMGN529 compound for the treatment of NHL.  Based on  ACS

estimates, we believe approximately 70,800 new  cases of NHL will be diagnosed  in the U.S. in 2014.

IMGN779—Our preclinical IMGN779 compound is a  potential  treatment for  acute myeloid
leukemia, or AML. Based on ACS estimates, we  believe approximately 18,900 new cases of AML will
be diagnosed in the U.S. in 2014.

Out-licenses and Collaborations

We  selectively license restricted access to our  ADC technology  to  other companies  to  provide us
with cash to fund our own product programs and to expand the utilization of  our technology. These

7

agreements typically provide the licensee with rights to use  our ADC technology with its  antibodies or
related targeting vehicles to a defined  target to develop products. The licensee is  generally responsible
for the development, clinical testing,  manufacturing,  registration and commercialization of any resulting
product  candidate. As part of these agreements,  we are  generally  entitled to receive upfront fees,
potential milestone payments, royalties on the sales of any resulting  products and research and
development funding based on activities  performed at our collaborative partner’s request. We are also
compensated for preclinical and clinical materials  supplied to our partners.

We  only receive royalty payments from our  out-licenses  after a product  candidate developed under

the license has been approved for marketing and commercialized.  Additionally, the largest milestone
payments under our existing collaborations  usually  are on  later-stage events,  such as commencement of
pivotal clinical trials, product approval  and achievement of defined  annual  sales levels. Achievement of
product  approval requires, at a minimum, favorable completion of preclinical  development and
evaluation, assessment of early-stage clinical trials, advancement  into  pivotal Phase II and/or Phase  III
clinical testing, completion of this later-stage  clinical testing with  favorable results, and completion of
regulatory submissions and a positive  regulatory decision. We have  a license with Roche relating to
Kadcyla that provides us with royalty revenue and may provide  us with additional milestone payments.
Kadcyla is currently our only source of  royalty revenue.  Below  is a table setting forth our active
agreements and current status of the  product candidates being developed  thereunder:

Agreement Type

Effective Date(s)

Development Status(1)

Partner

Roche(2)

Amgen(3)

Sanofi

Sanofi(4)

Biotest

Multiple single-targets

Multiple single-targets

Multiple single-targets

Right-to-test

Single-target

Bayer HealthCare

Single-target

Novartis(4)

Lilly(4)

CytomX

Right-to-test

Right-to-test

Right-to-test

2000

2000

2003

2006

2006

2008

2010

2011

2014

Marketed

Phase I

Phase II

Research/Preclinical

Phase I

Phase I

Research/Preclinical

Research/Preclinical

Research/Preclinical

(1) For agreements involving multiple targets, development status denotes the most advanced  program

under the collaboration.

(2) Roche has five single-target licenses.  Pursuant to the license  covering  the target HER2, which was
entered into in 2000, a product candidate, Kadcyla,  has received marketing approval in the US,
Japan and the EU, along with various  other  countries. The remaining four  licenses were taken
between 2005 and 2008 under another agreement established in 2000,  and the  development status
of product candidates under each of  those  licenses is  research/preclinical.

(3) Amgen has four exclusive, single-target licenses,  one of which has been sublicensed by Amgen to

Oxford  BioTherapeutics Ltd.

(4)

Sanofi,  Novartis and Lilly each have the right to take  a defined number of exclusive, single-target
options that provide the right to take  a defined number of single-target licenses, on  pre-negotiated
terms, to specified targets during the respective  option periods. As of  June  30, 2014, Novartis  has
taken two exclusive single-target licenses and one license to two related targets, one on  an
exclusive basis and the second on a non-exclusive basis; Lilly has taken an  exclusive  license to a
single target; and, Sanofi has taken an exclusive license to a single target.

8

Roche

In May 2000, we granted Genentech, now  a unit of Roche,  an exclusive development and

commercialization license to use our maytansinoid  ADC technology with antibodies, such  as
trastuzumab, or other proteins that target HER2. In February 2013, the  US FDA  granted marketing
approval to the HER2-targeting ADC  compound, Kadcyla. Roche received marketing approval for
Kadcyla in Japan and in the EU in September 2013 and November 2013, respectively. It has  also
received marketing approval in various other countries around the world. We received  a $2 million
upfront payment from Roche upon execution of the agreement.  We are also entitled  to  receive up  to a
total of $44 million in milestone payments,  plus tiered royalties on the commercial  sales  of  Kadcyla or
any other resulting products as described  below. To date we have received $34  million  of  the
$44 million in potential milestone payments.

The royalty term is determined on a country-by-country basis, and is initially 10 years from  the
date  of  first commercial sale of Kadcyla  in  the country. If, on such  10th anniversary, Kadcyla is covered
by a valid claim under any patents controlled  by  us  (excluding  patents jointly owned by us and
Genentech), then royalties remain payable on sales of Kadcyla in that country for an additional 2 years
and no more.

The following two territories are used  in our agreement with Genentech  to  determine the  Kadcyla
sales levels for the calculation of the  applicable tiered  royalty  levels: (1) the US and  (2) the rest of  the
world. Royalties on sales of Kadcyla are paid quarterly based on net sales in  each territory in
accordance with a tiered structure calculated separately in  each of the two territories as follows:

(cid:127) 3% of net sales up to $250 million  in the  calendar year;

(cid:127) 3.5% of net sales above $250 million and up to $400 million  in the calendar year;

(cid:127) 4% of net sales above $400 million  and up to $700 million  in the calendar year;  and

(cid:127) 5% of net sales above $700 million  in  the calendar year.

Royalties will be reduced to a flat 2%  of net sales in any country at any  time  during the royalty
term in which Kadcyla is not covered  by  a valid claim under any patents controlled by us (excluding
patents jointly owned by us and Genentech or solely owned by Genentech) in  such country. The sales
in the country count towards the annual sales in that territory for purposes  of  calculation  of  sales  tiers.

The license agreement also provides for  certain adjustments to the royalties payable  to  us  if

Genentech makes certain third party  license  payments in  order to exploit the  ADC technology
components of Kadcyla, although such adjustments would in no event reduce the royalties  payable for
any country below the greater of 50% of  the royalties otherwise  payable with respect to sales of
Kadcyla in such country, or 2% of net sales in  such country. As of the date of this annual report  on
Form 10-K, we are unaware of any facts or circumstances  that would give rise to such  an adjustment.

Roche may terminate this agreement  for convenience at any  time upon 90 days’  prior written
notice to us. The agreement may also be terminated  by  either party for a material breach by the  other,
subject to notice and cure provisions. Unless earlier  terminated, the agreement will  continue in  effect
until the expiration of Roche’s royalty  obligations.

In fiscal  year 2014 we received two $5  million  milestone payments in connection with marketing
approval of Kadcyla in Japan and in the  EU. Through June 30,  2014, we  have received  and recognized
a total of $34.0 million in milestone  payments under this agreement. The next potential  milestone we
will be entitled to receive will be a $5  million regulatory  milestone for marketing approval of Kadcyla
for a first extended indication as defined  in  the agreement.

Roche, through its Genentech unit, also  has licenses for the exclusive right  to  use our maytansinoid

ADC technology with antibodies to four  undisclosed  targets,  which were granted  under the terms of a

9

separate May 2000 right-to-test agreement  with Genentech. For each  of  these licenses  we received a
$1 million license fee and are entitled to receive up to a total  of $38 million in milestone payments  and
also royalties on the sales of any resulting  products.  We have not received any milestone payments from
these agreements through June 30, 2014. Roche is responsible for the development,  manufacturing, and
marketing of any products resulting from  these licenses.  Roche no longer has the right to take
additional licenses  under the right- to-test  agreement.

Amgen

Under a now-expired right-to-test agreement, in September  2009, November 2009 and  December
2012, Amgen took three exclusive development and commercialization licenses, for which  we received
an exercise fee of $1 million for each  license taken. In May  2013, Amgen  took  one  non-exclusive
development and commercialization license, for  which we received an exercise fee of $500,000. In
October 2013, the non-exclusive license  was amended  and  converted to an exclusive license,  for which
Amgen paid an additional $500,000 fee  to  us.  Amgen has sublicensed its rights under this license to
Oxford  BioTherapeutics Ltd. We are  entitled  to  receive up  to  a total of  $34 million  in milestone
payments for each exclusive license, plus royalties on  the commercial sales of any resulting products.

In November 2011, the IND applications to the FDA  for two compounds developed under the

2009 development and commercialization licenses became active,  which triggered  two $1 million
milestone payments to us. The next potential milestone we will  be  entitled to receive  under either  of
these two 2009 development and commercialization licenses will  be  a development  milestone for the
first dosing of a patient in a Phase II  clinical trial, which will  result  in a $3  million payment being due.
The next potential milestones we will  be  entitled to receive under the December 2012  and May 2013
development and commercialization licenses will be a $1  million development  milestone for IND
approval.

Amgen may terminate each development and  commercialization license  for  convenience upon
prior notice to us. Each license may also be terminated by either  party for a  material  breach  by  the
other, subject to notice and cure provisions. Unless earlier terminated, each license will continue  in
effect until the expiration of Amgen’s royalty obligations,  which are  determined on  a
product-by-product and country-by-country basis. For each  product and  country, Amgen’s  royalty
obligations commence with the first commercial  sale of that product in that country,  and extend  until
the later of either the expiration of the last-to-expire ImmunoGen patent covering that product in that
country or the expiration for that country of  the minimum royalty  period specified  in each development
and commercialization license.

Sanofi

Collaboration Agreement

In July 2003, we entered into a broad collaboration agreement  with Sanofi  (formerly Aventis) to
discover, develop and commercialize antibody-based  products.  The  collaboration  agreement provides
Sanofi with worldwide development and  commercialization rights to new antibody-based  products
directed to targets  that are included in  the collaboration, including  the exclusive right to use our
maytansinoid ADC technology in the creation of products  directed to these targets.  The  product
candidates (targets) currently in development under the collaboration  include SAR3419 (CD19),
SAR650984 (CD38), SAR566658 (CA6)  and SAR408701 (CEACAM5) and one earlier-stage compound
that has yet to be disclosed. We are entitled to receive  milestone payments  potentially totaling
$21.5 million, per target, plus royalties on  the commercial sales  of any  resulting products.

The agreement may be terminated by either party for  a material breach by the other, subject  to
notice and cure provisions. Unless earlier  terminated,  the agreement will continue in effect until  the
expiration of Sanofi’s royalty obligations, which are determined on a product-by-product and

10

country-by-country basis. For each product and country, Sanofi’s royalty obligations  commence upon
first commercial sale of that product in that country, and extend  until  the later  of  either the expiration
of the last-to-expire ImmunoGen patent covering that product  in that country or the  expiration for that
country of the minimum royalty period specified in the  agreement.

The collaboration  agreement also provides us an  option to certain  co-promotion rights  in the U.S.
on a product-by-product basis. The terms  of  the collaboration agreement allow Sanofi to terminate our
co-promotion rights if there is a change  in  control  of ImmunoGen.

Through June 30, 2014, we have received  and recognized a total of  $16.5 million in milestone
payments related to compounds covered  under  this  agreement now and in the  past, including  a total of
$8 million in milestone payments related  to two product candidates previously in the collaboration  that
have been returned to us along with  the  rights to the respective targets. In  July 2014,  Sanofi initiated a
Phase II clinical trial for SAR650984 which triggered  a $3 million payment  to  us.

The next potential milestone we will be entitled to receive  with respect to each of  SAR3419 and

SAR650984 will be a development milestone for initiation of  a  Phase III clinical trial, which  will result
in each case in a $3 million payment  being due. The next  potential milestone we will  be  entitled to
receive with respect to SAR566658 will be a  development milestone for initiation  of  a Phase  IIb clinical
trial (as defined in the agreement), which  will result  in a $3 million payment being due. The next
potential  milestone  we  will  be  entitled  to  receive  for  each  of  SAR408701  and  the  unidentified  target
will  be  a  development  milestone  for  commencement  of  a  Phase  I  clinical  trial,  which  will  result  in  each
case in a  $1 million payment being due.

Right-to-Test Agreement

In December 2006, we entered into a separate right-to-test  agreement with Sanofi. The agreement
provides Sanofi with the right to (a)  test  our maytansinoid ADC technology with Sanofi’s antibodies  to
targets that were not included in the  collaboration  agreement described above under  a right-to-test, or
research, license, (b) take exclusive options, with  certain restrictions, to specified targets for specified
option periods and (c) upon exercise  of  those  options,  take  exclusive  licenses to use our maytansinoid
ADC technology to develop and commercialize  products directed to the specified targets  on terms
agreed upon at the inception of the right-to-test agreement. The right-to-test agreement had a
three-year original term from the activation  date that was  renewed by  Sanofi in August 2011 for its
final three-year term ending August  31, 2014 by payment of a $2  million  extension fee.  No additional
extensions are included in this agreement,  although any outstanding  options will remain in  effect  for
the remainder of their respective option terms.

For each development and commercialization license taken, we are entitled to receive an exercise

fee of $2 million and up to a total of $30 million in  milestone payments, plus royalties  on the
commercial sales of any resulting products. In  December  2013,  Sanofi took its first exclusive
development and commercialization license under  the right-to-test agreement, for which we received an
exercise fee of $2 million. The next payment we could receive would either be a $2 million
development milestone payment with the  initiation of a  Phase I clinical  trial under  the first
development and commercialization license taken, or a $2 million  exercise fee  for the  execution of a
second  license.

Each  development and commercialization license  may  be  terminated by either  party for  a material

breach by the other, subject to notice and  cure provisions. Unless earlier  terminated, each  license will
continue in effect until the expiration of Sanofi’s royalty obligations, which are  determined on  a
product-by-product and country-by-country basis. For each  product and  country, Sanofi’s  royalty
obligations commence with the first commercial  sale of that product in that country,  and extend  until
the later of either the expiration of the last-to-expire ImmunoGen patent covering that product in that

11

country or the expiration for that country of  the minimum royalty  period specified  in each development
and commercialization license.

Biotest

In July 2006, we granted Biotest an exclusive  development and  commercialization license to our

maytansinoid ADC technology for use  with antibodies that target CD138. The  product candidate
BT-062 is in development under this agreement.  We received a $1  million  upfront payment  from
Biotest upon execution of the agreement.  We are  also entitled to receive  up  to  a total of $35.5 million
in milestone payments, plus royalties  on  the commercial sales of any resulting products. Through
June 30, 2014, we have received and  recognized  a total of $500,000 in milestone  payments under this
agreement. The next potential milestone  we  will  be  entitled to receive will  be  a development milestone
for commencement of a Phase IIb clinical trial (as defined in the agreement), which will result in  a
$2 million payment being due.

The agreement also provided us with the right  to  elect,  at  specific stages  during the  clinical
evaluation of any compound created under the agreement,  to  participate  in the  U.S. development and
commercialization of that compound  in  lieu of receiving  the milestone payments not yet earned and
royalties on sales in the U.S. Currently, we can  exercise  this right during an exercise period specified  in
the agreement by notice and payment to Biotest of an agreed upon opt-in fee of $15  million. Upon
exercise of this right, we would share equally with Biotest the associated further costs of product
development and commercialization in  the U.S.  along with  the profit, if any, from product sales in the
U.S. We would also be entitled to receive  royalties,  on a  reduced basis, on  product sales outside the
U.S.

Biotest may terminate the agreement  for convenience at any  time prior to  our election  to
participate in the U.S. development and  commercialization of a compound  created under this
agreement upon prior notice to us. The agreement may also be terminated by either  party for  a
material breach by the other, subject  to  notice and cure provisions. Unless earlier terminated, the
agreement will continue in effect until the  expiration of  Biotest’s  royalty obligations, which  are
determined on a product-by-product  and country-by-country basis. For each product  and country,
Biotest’s royalty obligations commence upon first commercial sale  of  that  product in  that  country, and
extend until the later of either the expiration of the last-to-expire ImmunoGen  patent  covering that
product  in that country or the expiration for that country of the minimum royalty  period specified in
the agreement.

Bayer HealthCare

In October 2008, we granted Bayer HealthCare an  exclusive  development and  commercialization

license to our maytansinoid ADC technology for use with antibodies  or  other proteins that target
mesothelin. The product candidate BAY  94-9343 is in  development under  this agreement.  We received
a $4 million upfront payment upon execution of the agreement. We  are also  entitled to receive, for
each  product developed and marketed by Bayer HealthCare  under this agreement, up to a total of
$170.5 million in milestone payments, plus  royalties on the commercial sales of any resulting  products.

Bayer HealthCare may terminate the agreement for convenience  at  any time upon  prior written
notice to us. The agreement may also be terminated  by  either party for a material breach by the  other,
subject to notice and cure provisions. We  may  also terminate the agreement upon the occurrence  of
specified events. Unless earlier terminated, the  agreement will  continue in effect until the expiration of
Bayer HealthCare’s royalty obligations,  which  are determined  on a  product-by-product and
country-by-country basis. For each product and country, Bayer HealthCare’s royalty  obligations
commence upon first commercial sale  of that product  in that country, and extend until  the later  of

12

either the expiration of the last-to-expire  ImmunoGen patent covering  that  product in  that  country  or
the expiration for that country of the  minimum  royalty period specified  in the  agreement.

Through June 30, 2014, we have received  and recognized a total of  $3 million in milestone
payments under this agreement. The next  potential milestone we will be entitled to receive will  be  a
development milestone for commencement of a non-pivotal Phase II clinical trial, which  will  result in a
$4 million payment being due.

Novartis

In October 2010, we entered into a right-to-test agreement with Novartis. The agreement  provides

Novartis with a right to (a) test our ADC  technology  with individual antibodies  provided by Novartis
under a right-to-test, or research, license, (b)  take exclusive  options, with  certain restrictions,  to
individual targets selected by Novartis for specified  option periods, and  (c) upon  exercise of those
options, take exclusive licenses to use  our  ADC technology to develop and commercialize  products for
a specified number of individual targets  on terms agreed upon at the inception of  the right-to-test
agreement. The initial three-year term  of the right-to-test agreement was  extended by Novartis in
October 2013 for an additional one-year period by  payment of a  $5 million fee  to  the Company. In
addition to the one-year extension taken in October  2013, the terms of the right-to-test agreement
allow Novartis to extend the research term for one additional  one-year  period by payment  of additional
consideration. The terms of the right-to-test agreement require Novartis to exercise its options for the
development and commercialization licenses by the end  of  the term of the research license.

We  received a $45 million upfront payment in  connection with the execution of the  right-to-test
agreement, and we are also entitled to receive additional payments under the  agreement for  research
and development activities performed on behalf of Novartis during the term  of  the agreement. For
each  development and commercialization license taken, we are entitled to  receive an exercise fee of
$1 million and up to a total of $199.5  million in milestone payments,  plus royalties on the commercial
sales of any resulting products.

In March 2013, we and Novartis amended  the right-to-test agreement so that Novartis can take  a

license to develop and commercialize products directed  at  two pre-defined and related undisclosed
targets, one target licensed on an exclusive  basis and the other  target initially  licensed on a
non-exclusive basis. The target licensed  on a  non-exclusive basis  may  be  converted  to  an exclusive
target by notice and payment to us of an  agreed upon fee  of at least $5 million, depending on specific
circumstances. We received a $3.5 million fee in connection with the  execution of the amendment to
the agreement. We may be required  to  credit  this fee against future milestone payments if Novartis
discontinues the development of a specified product under certain  circumstances.

In connection with the amendment, in  March 2013, Novartis took the license referenced above

under the right-to-test agreement, as  amended,  enabling  it to develop and commercialize products
directed at the two targets. We received  a $1  million  upfront fee  with the  execution of this license.
Additionally, the execution of this license provides  us  the opportunity  to receive milestone payments
totaling $199.5 million or $238 million,  depending on the composition of  any resulting  products, plus
royalties on the commercial sales of any  resulting products.

In October 2013 and November 2013, Novartis  took its second and third exclusive licenses to

single targets, each triggering a $1 million  payment  to  the Company  and the opportunity to receive
milestone payments totaling $199.5 million for each license taken, plus royalties on  the commercial
sales of any resulting products. The next  payment  the Company  could receive would either  be  a
$5 million development milestone for  commencement of a  Phase I clinical trial under  any of  these
three licenses, or a $1 million exercise fee for  the execution of a  fourth license.

13

Novartis may terminate any development and commercialization  license  for convenience  upon
prior notice to us. Each license may also be terminated by either  party for a  material  breach  by  the
other, subject to notice and cure provisions. Unless earlier terminated, each development and
commercialization license will continue in  effect until the expiration of  Novartis’  royalty obligations,
which  are determined on a product-by-product  and  country-by-country  basis. For each product  and
country, Novartis’ royalty obligations  commence upon first commercial sale of that product  in that
country, and extend until the later of either the expiration of the last-to-expire ImmunoGen  patent
covering that product in that country  or  the expiration for that country of the  minimum royalty period
specified in each license.

Lilly

In December 2011, we entered into a three-year right-to-test  agreement with  Lilly. The agreement
provides Lilly with the right to (a) take exclusive options, with  certain restrictions,  to  individual targets
selected  by Lilly for specified option periods,  (b)  test our maytansinoid ADC  technology with  Lilly’s
antibodies directed to the optioned targets under  a right-to-test, or research, license, and  (c)  upon
exercise of those options take exclusive licenses to use our  maytansinoid  ADC technology  to  develop
and commercialize products for a specified number  of individual targets on terms  agreed upon at the
inception of the right-to-test agreement.  Lilly must exercise its options for  the development and
commercialization licenses by the end  of  the term of  the right-to-test agreement, after which any  then
outstanding options will lapse. Lilly has  the right to extend the three-year right-to-test period for  up to
two six-month periods by payment to  us of  additional consideration. Under the  terms of the agreement,
Lilly took an exclusive development and  commercialization license to a single target in August 2013.

We  received a $20 million upfront payment in  connection with the execution of the  right-to-test

agreement, and for the first development  and commercialization license taken in August 2013 and
amended in December 2013, we received an  exercise fee  in the amount of  $2 million and  are entitled
to receive up to a total of $199 million  in milestone payments,  plus royalties on the  commercial sales of
any resulting products. Lilly has the right to elect, at its discretion, which  of  the two  additional
development and commercialization licenses it  has a right to take  under the  right-to-test agreement  will
have no exercise fee and which will have an  exercise fee  of $2 million. With respect to any subsequent
development and commercialization license taken, if  Lilly elects that  the  $2 million exercise fee is
payable, we are entitled to receive, in  addition  to  the exercise fee,  up to a  total  of $199 million in
milestone payments, plus royalties on the  commercial sales of any resulting products. If Lilly elects that
no exercise fee is payable when it takes a development and commercialization  license, the  Company is
entitled to receive up to a total of $200.5  million in milestone payments, plus royalties on the
commercial sales of any resulting products. The next payment we could receive would either  be  a
$5 million development milestone payment with  the initiation of a Phase I clinical trial under the first
development and commercialization license taken, or a $2 million  exercise fee  for the  execution of an
additional license if Lilly elects to pay  the exercise fee with  respect  to  such license.

Lilly may terminate any development and commercialization license for  convenience upon  prior
notice to us. Each license may also be terminated  by  either party for a material breach by the  other,
subject to notice and cure provisions. We  may  also terminate the agreement upon the occurrence  of
specified events. Unless earlier terminated, each  development and commercialization license  will
continue in effect until the expiration of Lilly’s royalty obligations, which are determined on a
product-by-product and country-by-country basis. For each  product and  country, Lilly’s  royalty
obligations commence upon first commercial sale of that  product in that country,  and extend until the
later of either the expiration of the last-to-expire  ImmunoGen patent covering that product in that
country or the expiration for that country of  the minimum royalty  period specified  in each license.

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CytomX

In January 2014, we entered into a reciprocal right-to-test agreement with CytomX.  The agreement

provides CytomX with the right to test  our  ADC technology with CytomX Probodies  to  create
Probody-drug conjugates (PDCs) directed  to a  specified  number  of targets under a right-to-test, or
research, license, and to subsequently  take an exclusive, worldwide license to use our ADC  technology
to develop and commercialize PDCs directed to the  specified targets on terms agreed  upon at the
inception of the right-to-test agreement.  We  received no upfront  cash payment in connection with the
execution of the right-to-test agreement. Instead, we received reciprocal rights to CytomX’s Probody
technology whereby we were provided  the  right  to  test CytomX’s Probody technology to create PDCs
directed to a  specified number of targets  and to subsequently take  exclusive, worldwide licenses to
develop and commercialize PDCs directed to the  specified targets on terms agreed  upon at the
inception of the right-to-test agreement.  The terms of the  right-to-test agreement require us and
CytomX to each take its respective development and commercialization licenses by the end  of  the term
of the research license. In addition, both we  and CytomX  are required to perform specific  research
activities under the right-to-test agreement on behalf of  the other party for no  monetary  consideration.

With respect to the development and  commercialization license that may be taken by CytomX, we
are entitled to receive up to a total of  $160 million in milestone payments per license,  plus royalties  on
the commercial sales of any resulting product. Assuming  no annual maintenance  fee is payable  as
described below, the next payment we could receive would be a $1 million development  milestone
payment with commencement of a Phase  I  clinical trial.

With respect to any development and  commercialization license that may be taken  by  us, we will

potentially be required to pay up to  a total of $80  million in milestone payments per license,  plus
royalties on the commercial sales of any  resulting product.  Assuming no  annual maintenance  fee  is
payable as described below, the next payment we could be required  to  make is a $1  million
development milestone payment with commencement of a  Phase I clinical trial.

In addition, each party may be liable to pay annual maintenance fees to the other  party if  the

licensed PDC product candidate covered  under each development and commercialization  license has
not progressed to a specified stage of development within  a specified time frame.

Patents, Trademarks and Trade Secrets

Our intellectual property strategy centers  on obtaining  patent  protection for our proprietary

technologies and product candidates.  As  of  June  30, 2014, our  patent portfolio had a total  of  472 issued
patents worldwide and 569 pending patent applications worldwide that we own or license from third
parties. We seek to protect our ADC  technology  and  our product candidates through  a multi-pronged
approach. In this regard, we have patents and patent applications covering antibodies and other
cell-binding agents, linkers, cell-killing agents  (e.g., tubulin-acting maytansinoids and DNA-acting
cell-killing agents), and complete ADCs, comprising  these  components and methods of making and
using each of the above. Typically, multiple issued patents and pending patent applications cover
various aspects of each product candidate.

We  consider our cell-killing agent technology  to  be  a key component of our overall corporate
strategy. We currently own 43 issued  U.S. patents  covering various embodiments of  our maytansinoid
technology including claims directed to certain maytansinoids, antibody-maytansinoid conjugates and
other cell-binding agents used with maytansinoids, and methods  of  making and using the same. In  all
cases, we have received or are applying  for comparable patents in  other jurisdictions including Europe
and Japan. We have issued patents that  cover numerous  aspects of the manufacture of both  our DM1
and DM4 cell-killing agents. These issued patents remain in  force until  various times between 2020  and
2026. We also have several composition  of matter patents covering various aspects  of our  DM4
cell-killing agent and antibody-maytansinoid conjugates  incorporating DM4 that are expected to remain

15

in force until 2024-2025. We have one issued  U.S. patent covering various aspects  of our  DNA-acting
cell-killing agents, which will expire in  2030. We also have seven additional pending U.S. patent
applications disclosing and claiming may  other  related embodiments of this technology. Patents that
may issue from these applications will,  if  issued,  expire between  2030 and 2033. In all cases, we are also
applying for comparable patents in other jurisdictions, including  Europe and Japan.

Our intellectual property strategy also includes  pursuing patents directed to linkers, antibodies,

conjugation methods, ADC formulations  and  the use of specific antibodies  and ADCs  to  treat certain
diseases.  In this regard, we have issued patents and pending patent applications related  to  many of our
linker technologies. These issued patents, expiring  in 2021-2031, and  any patents which may  issue from
the patent applications, cover antibody-maytansinoid  conjugates using these linkers. We also  have issued
U.S. patents and pending patent applications covering methods of assembling ADCs from  their
constituent antibody, linker and cell-killing agent moieties. These issued  patents  will  expire in
2021-2030, while any patents that may issue from pending patent applications also covering various
aspects of these technologies will, if issued,  expire between 2021  and 2034. We also have issued patents
and pending patent applications related to monoclonal antibodies  that may be a component of an  ADC
compound or may be developed as a  therapeutic, or  ‘‘naked,’’ antibody anticancer compound.

We  expect our continued work in each of these areas  will  lead to other patent applications. In all
such cases, we will either be the assignee  or  owner of such patents  or have  an exclusive license  to  the
technology covered by the patents.

The rates at which we are entitled to receive royalties based on  sales of  Kadcyla in  any particular
country depend in part on whether the  manufacture,  use or  sale of Kadcyla is covered by ImmunoGen
patent rights in that country. In this regard, we own  patents in the U.S. and Europe  covering the
composition of matter of Kadcyla that expire at the earliest in  2023 and  2024, respectively, and may be
eligible for extension of those terms under applicable patent laws in those jurisdictions. We also own
patents in the U.S. and Europe that cover  various elements  of the manufacture  of  Kadcyla, with
expiration dates extending to at least  2027 and 2026,  respectively. Notwithstanding  these  patent  terms,
the period during which we are entitled to receive royalties based  on sales of Kadcyla  in any  country
does not extend beyond the 12th anniversary of the date of the first commercial sale of Kadcyla in such
country.

We  cannot provide assurance that the  patent  applications will  issue as  patents  or that any  patents,

if issued, will provide us with adequate  protection  against competitors with respect to the  covered
products, technologies or processes. Defining the  scope  and term  of patent protection  involves complex
legal and  factual analyses and, at any  given  time, the  result of  such analyses may be uncertain. In
addition, other parties may challenge  our patents  in litigation or administrative proceedings resulting  in
a partial or complete loss of certain patent rights  owned or controlled by  ImmunoGen,  Inc.
Furthermore, as a patent does not confer  any  specific freedom to operate, other parties may  have
patents that may block or otherwise hinder  the development and commercialization of our technology.

In addition, many of the processes and much of the  know-how that  are  important to us depend
upon the skills, knowledge and experience of our key scientific and  technical personnel, which skills,
knowledge and experience are not patentable.  To protect  our rights in these areas,  we require  that  all
employees, consultants, advisors and  collaborators enter into confidentiality agreements with  us.
Further, we require that all employees enter into assignment of invention  agreements as a  condition of
employment. We cannot provide assurance,  however, that  these  agreements will  provide adequate  or
any meaningful protection for our trade  secrets,  know-how or other proprietary  information in the
event of any unauthorized use or disclosure of such trade secrets,  know-how  or proprietary  information.
Further, in the absence of patent protection, we  may be exposed to competitors who independently
develop substantially equivalent technology  or otherwise gain access to our trade  secrets,  know-how or
other proprietary information.

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Competition

We  focus on highly competitive areas of product development. Our competitors include  major
pharmaceutical companies and other biotechnology firms.  For  example, Pfizer, Seattle Genetics,  Roche
and Bristol-Myers Squibb have programs  to attach  a proprietary  cell-killing small  molecule to an
antibody  for targeted delivery to cancer cells. Pharmaceutical and  biotechnology companies, as well  as
other institutions, also compete with us  for promising targets for  antibody-based therapeutics and in
recruiting highly qualified scientific personnel.  Additionally, there are non-ADC  therapies available
and/or in  development for the cancer  types we and our partners are targeting.  Many competitors  and
potential competitors have substantially greater  scientific, research and product  development
capabilities, as well as greater financial, marketing and human resources than we do.  In addition, many
specialized biotechnology firms have  formed collaborations  with large, established companies  to  support
the research, development and commercialization  of  products  that may  be  competitive with ours.

In particular, competitive factors within the antibody and cancer therapeutic  market  include:

(cid:127) the safety and efficacy of products;

(cid:127) the timing of regulatory approval and commercial  introduction;

(cid:127) special regulatory designation of products,  such as  Orphan Drug designation; and

(cid:127) the effectiveness of marketing, sales, and reimbursement efforts.

Our competitive position depends on our ability to develop effective proprietary products,

implement clinical development programs,  production plans and marketing plans,  including
collaborations with other companies with greater marketing resources than ours, and  to  obtain  patent
protection and secure sufficient capital  resources.

Continuing development of conventional and  targeted chemotherapeutics by large pharmaceutical

companies and biotechnology companies  may result in new compounds that may  compete with our
product  candidates. Antibodies developed by  certain of these companies have been approved for  use as
cancer therapeutics. In the future, new  antibodies or other  targeted  therapies  may compete with  our
product  candidates. Other companies  have created or have programs to create potent cell-killing agents
for attachment to antibodies. These companies may compete with  us for technology out-license
arrangements.

Regulatory Matters

Government Regulation and Product Approval

Government authorities in the U.S.,  at  the federal, state and local level, and other  countries
extensively regulate, among other things, the research, development,  testing, manufacture,  quality
control, approval, labeling, packaging,  storage,  record-keeping, promotion, advertising, distribution,
marketing and export and import of  products such as those we are developing. A new drug must be
approved by the FDA through the new drug  application, or NDA, process and a new biologic must be
approved by the FDA through the biologics license application, or BLA,  process before it may be
legally marketed in the U.S.

U.S. Drug Development Process

In the U.S., the FDA regulates drugs under the  federal Food, Drug, and Cosmetic Act,  or FDCA,

and in the case of biologics, also under the Public  Health Service  Act, or  PHSA, and implementing
regulations. The process of obtaining regulatory approvals and the subsequent compliance with
appropriate federal, state, local, and foreign statutes  and regulations require the expenditure of
substantial time and financial resources.  Failure to comply with  the applicable  U.S. requirements at any

17

time during the product development process, approval process or after  approval, may subject an
applicant to administrative or judicial  sanctions.  These sanctions could  include the FDA’s  refusal to
approve pending applications, withdrawal of an approval, a clinical hold, warning letters,  product
recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines,
refusals of government contracts, restitution,  disgorgement, or civil or criminal penalties. Any agency or
judicial enforcement action could have a  material adverse effect on us.  The process required  by  the
FDA before a drug or biologic may be  marketed in  the U.S. generally involves the following:

(cid:127) completion of preclinical laboratory tests,  animal studies and formulation studies  according to

current Good Laboratory Practices (cGLP) or other applicable regulations;

(cid:127) submission to the FDA of an IND  which must  become effective  before  human clinical  trials may

begin;

(cid:127) performance of adequate and well-controlled  human clinical trials according  to  current Good
Clinical Practices (cGCP) to establish the safety  and efficacy of  the proposed  drug  for its
intended use;

(cid:127) submission to the FDA of an NDA  or BLA;

(cid:127) satisfactory completion of an FDA  inspection of the manufacturing facility or facilities at which

the drug is produced to assess compliance with current  Good Manufacturing  Practice (cGMP) to
assure that the facilities, methods and controls are adequate to preserve  the  drug’s identity,
strength, quality and purity; and

(cid:127) FDA review and approval of the NDA  or BLA.

Once a pharmaceutical candidate is identified for development it enters the  preclinical testing
stage. Preclinical tests include laboratory  evaluations  of product chemistry, toxicity and formulation, as
well as animal studies. An IND sponsor must submit the  results of the  preclinical tests, together with
manufacturing information and analytical  data, to the  FDA as  part of  the IND. The sponsor  will also
include a protocol detailing, among other things,  the objectives of the  first  phase of the clinical trial,
the parameters to be used in monitoring safety, and the effectiveness criteria to be evaluated, if the
first phase lends itself to an efficacy evaluation. Some preclinical testing may continue even after the
IND is submitted. The IND automatically  becomes effective 30 days  after receipt by the FDA,  unless
the FDA, within the 30-day time period,  places  the clinical  trial on a clinical hold. In such a  case, the
IND sponsor and the FDA must resolve  any outstanding  concerns before the clinical trial can begin.
Clinical holds also  may be imposed by the FDA at any time before or during  clinical trials  due  to  safety
concerns or non-compliance.

All clinical trials must be conducted  under the supervision of one or more qualified investigators in
accordance with cGCP regulations. They  must be conducted under protocols detailing  the objectives of
the trial, dosing procedures, subject selection and exclusion criteria and the safety and effectiveness
criteria to be evaluated. Each protocol  must be submitted  to  the  FDA  as part  of the IND, and progress
reports detailing the results of the clinical  trials must be submitted at least annually. In addition, timely
safety reports must be submitted to the FDA and the investigators  for serious and  unexpected adverse
events. An institutional review board,  or IRB, at each institution  participating in the clinical trial must
review and approve each protocol before  a clinical trial commences at that institution and  must  also
approve the information regarding the trial and the consent form that must  be  provided to each trial
subject or his or her legal representative,  monitor the study until completed  and otherwise comply with
IRB regulations.

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Human clinical trials are typically conducted  in three  sequential phases that may overlap or be

combined:

(cid:127) Phase I: The product candidate is initially introduced into healthy  human subjects  and tested for
safety, dosage tolerance, absorption,  metabolism, distribution and excretion. In the  case of some
products for severe or life-threatening diseases, such as cancer, especially  when the product may
be too inherently toxic to ethically administer to healthy  volunteers, the  initial human testing is
often conducted in patients.

(cid:127) Phase II: This phase involves clinical trials in a limited patient population to identify possible

adverse effects and safety risks, to preliminarily evaluate the efficacy of the product for specific
targeted diseases and to determine dosage tolerance and  optimal dosage.

(cid:127) Phase III: Clinical trials are undertaken to further evaluate dosage, clinical  efficacy and safety  in
an expanded patient population at geographically  dispersed clinical study sites. These  clinical
trials are intended to establish the overall risk-benefit  ratio of the  product candidate  and
provide, if appropriate, an adequate  basis for product  labeling.

The FDA or the sponsor may suspend  a clinical  trial at  any time on various grounds, including  a

finding that the research subjects or patients are being exposed to an unacceptable health risk.
Similarly, an IRB can suspend or terminate approval of a clinical trial at its institution if  the clinical
trial is not being conducted in accordance with  the IRB’s  requirements or if  the drug has been
associated with unexpected serious harm to patients. Phase  I,  Phase II,  and Phase III testing  may not
be completed successfully within any  specified  period, if at all.

During  the development of a new drug,  sponsors  are given  opportunities  to meet with the FDA at
certain points. These points may be prior  to  submission  of  an IND,  at the end  of Phase II, and  before
an NDA or BLA is submitted. Meetings  at other times may be requested. These meetings can provide
an opportunity for the sponsor to share information about the data  gathered to date, for  the FDA  to
provide advice, and for the sponsor and  FDA to reach agreement on the next  phase of development.
Sponsors typically use the End of Phase  II meeting  to  discuss  their Phase II  clinical results and present
their plans for the pivotal Phase III clinical  trial that they believe will support  approval of the new
drug. If this type of discussion occurs,  a  sponsor may be able to request a  Special  Protocol  Assessment,
or SPA, the purpose of which is to reach  agreement  with the FDA on the design  of  the Phase  III
clinical trial protocol design and analysis that  will form  the primary basis  of  an efficacy claim.

According to FDA guidance for industry on  the SPA process, a sponsor that meets  the

prerequisites may make a specific request for  a special protocol assessment  and provide  information
regarding the design and size of the proposed clinical trial.  The  FDA is  required  to  evaluate the
protocol within 45  days of the request to assess whether  the proposed trial  is adequate, and  that
evaluation may result in discussions and  a request for  additional  information. A SPA request must be
made before the proposed trial begins, and all open issues must  be  resolved  before  the trial begins. If a
written agreement is reached, it will  be  documented and made part of the record. The agreement  will
be binding on the  FDA and may not be changed by the sponsor or the FDA  after the trial begins
except with the written agreement of the  sponsor and the FDA or if  the FDA determines that a
substantial scientific issue essential to  determining the safety or efficacy of the drug was identified  after
the testing began. If the sponsor makes  any unilateral  changes  to  the approved protocol,  the agreement
will be invalidated.

Concurrent with clinical trials, companies usually complete additional animal studies and  must  also
develop additional information about the  chemistry and physical characteristics of the drug and finalize
a process for manufacturing the product in commercial quantities in  accordance with cGMP
requirements. The manufacturing process must be capable  of consistently  producing quality batches of
the product candidate and, among other things,  the manufacturer must develop methods  for testing the

19

identity, strength, quality and purity of the final drug. Additionally, appropriate packaging  must  be
selected  and tested and stability studies must  be  conducted  to  demonstrate  that  the product candidate
does not undergo unacceptable deterioration over its shelf life.

U.S. Review and Approval Processes

The results of product development, preclinical studies and clinical trials, along  with descriptions of

the manufacturing process, analytical tests conducted on the chemistry of the  drug, proposed labeling,
and other relevant information are submitted to the FDA as  part  of  an NDA  or BLA requesting
approval to market the product. The submission of an  NDA or BLA is  subject to the payment  of user
fees; a waiver of such fees may be obtained under certain limited circumstances. The FDA reviews all
NDAs and BLAs submitted to ensure that  they are  sufficiently complete for substantive review  before
it accepts them for filing. The FDA may  request additional  information rather than accept an NDA or
BLA for filing. In this event, the NDA  or BLA  must  be  resubmitted with  the additional  information.
The resubmitted application also is subject  to  review before the FDA accepts it  for filing. Once the
submission is accepted for filing, the  FDA begins an  in-depth substantive review. FDA may refer the
NDA  or  BLA to an advisory committee for  review, evaluation and recommendation as to whether the
application should be approved and under what conditions. The FDA is not bound by the
recommendation of an advisory committee, but it  generally follows such recommendations. The
approval process is lengthy and often difficult, and the FDA may refuse to approve  an NDA or BLA  if
the applicable regulatory criteria are  not  satisfied or may  require additional clinical or other  data  and
information. Even if such data and information is submitted, the FDA may ultimately  decide that the
NDA  or  BLA does not satisfy the criteria  for approval. Data  obtained  from clinical trials are  not
always conclusive and the FDA may interpret data  differently than we interpret the  same data. The
FDA may issue a complete response letter, which  may require additional  clinical  or other data or
impose other conditions that must be  met in order to secure  final approval  of  the NDA or BLA,  or an
approved letter following satisfactory completion of all aspects  of the review process. The FDA reviews
an NDA to determine, among other  things, whether a  product is  safe and effective for  its  intended use
and whether its manufacturing is cGMP-compliant to assure and preserve the  product’s identity,
strength, quality and purity. The FDA reviews a BLA  to  determine, among other  things whether  the
product  is safe, pure and potent and  the facility  in which it  is manufactured, processed, packed  or held
meets standards designed to assure the  product’s continued safety, purity and  potency.  Before
approving an NDA or BLA, the FDA  will inspect the facility or  facilities  where the  product is
manufactured.

NDAs or BLAs receive either standard or priority  review. A drug representing a significant

improvement in treatment, prevention or  diagnosis of disease may  receive priority review.  Priority
review for an NDA for a new molecular  entity and original BLAs will be 6 months from the  date that
the NDA or BLA  is filed. In addition,  products studied for  their  safety and effectiveness in treating
serious or life-threatening illnesses and that provide  meaningful  therapeutic benefit over  existing
treatments may receive accelerated approval and may be approved on the  basis of adequate and
well-controlled clinical trials establishing  that  the drug product has an  effect on a  surrogate endpoint
that is reasonably likely to predict clinical benefit or on  the basis  of  an effect on  a clinical  endpoint
other than survival or irreversible morbidity. As a condition of approval, the FDA may require that a
sponsor  of a drug receiving accelerated  approval  perform  adequate and well-controlled post-marketing
clinical trials. Priority review and accelerated approval  do not change the standards  for approval, but
may expedite the approval process.

If a  product receives regulatory approval, the approval may be significantly  limited to specific
diseases  and dosages or the indications for  use may otherwise  be  limited, which could restrict  the
commercial value of the product. In addition, the  FDA may require  us to conduct Phase IV testing
which  involves clinical trials designed to further  assess a drug’s safety  and effectiveness after  NDA or

20

BLA approval, and may require testing and surveillance  programs to monitor the safety of approved
products which have been commercialized.

The Food and Drug Administration Safety and  Innovation Act,  or FDASIA, made permanent the

Pediatric Research Equity Act, or PREA,  which requires a sponsor  to  conduct  pediatric  clinical trials
for most drugs and biologicals, for a new  active ingredient, new indication,  new dosage form, new
dosing regimen or new route of administration. Under PREA, original  NDAs, BLAs and supplements
thereto, must contain a pediatric assessment unless the  sponsor  has received a deferral  or waiver.  The
required assessment must evaluate the safety and effectiveness  of the product  for the  claimed
indications in all relevant pediatric subpopulations and support dosing and administration for each
pediatric subpopulation for which the product  is safe and effective. The  sponsor or FDA  may request a
deferral of pediatric clinical trials for some or all of  the pediatric subpopulations. A deferral may be
granted for several reasons, including a finding  that the drug or  biologic is ready  for approval  for use in
adults before pediatric clinical trials are complete or that additional safety or  effectiveness data needs
to be collected before the pediatric clinical  trials begin. After  April 2013,  the FDA must send a
non-compliance letter to any sponsor  that fails to submit the required assessment,  keep a deferral
current or fails to submit a request for  approval of a  pediatric formulation.

Patent Term Restoration and Marketing Exclusivity

Depending upon the timing, duration and specifics of FDA approval of our drugs,  some of  our

U.S. patents may be eligible for limited  patent term extension under the Drug Price Competition and
Patent Term Restoration Act of 1984, referred  to  as the Hatch-Waxman Amendments. The Hatch-
Waxman Amendments permit a patent restoration term of up to five years as compensation for  patent
term lost during product development and  the FDA  regulatory review process. However,  patent  term
restoration cannot  extend the remaining  term of a patent beyond a total of 14 years from the  product’s
approval date. The patent term restoration period  is generally one-half the  time between  the effective
date  of  an IND, and the submission  date of an NDA or BLA,  plus the time between the submission
date  of  an NDA or BLA and the approval of that application. Only one patent applicable to an
approved drug is eligible for the extension, and the  extension must  be  applied for  prior to expiration  of
the patent. The United States Patent and Trademark  Office, in consultation with the  FDA,  reviews and
approves the application for any patent term extension  or restoration. In the  future, we intend  to  apply
for restorations of patent term for some of  our currently owned or licensed patents to add  patent  life
beyond their current expiration date,  depending on the expected length of clinical trials and other
factors involved in the filing of the relevant NDA.

Pediatric exclusivity is a type of marketing exclusivity  available in the U.S. The FDASIA made
permanent the Best Pharmaceuticals for Children Act, or BPCA, which  provides for  an additional
six months of marketing exclusivity if a  sponsor conducts  clinical trials in children in response to a
written request from the FDA, or a Written Request. If the  Written Request  does not include  clinical
trials in neonates, the FDA is required  to  include  its rationale for not requesting those clinical  trials.
The FDA may request studies on approved or unapproved  indications  in separate  Written Requests.
The issuance of a Written Request does  not  require the sponsor to undertake the  described clinical
trials. To date, we have not received any  Written Requests.

Biologics Price Competition and Innovation  Act of 2009

On March 23, 2010, President Obama signed into law the  Patient Protection and Affordable Care

Act which included the Biologics Price  Competition and Innovation Act of  2009, or BPCIA. The
BPCIA amended the PHSA to create an abbreviated approval pathway  for  two types of ‘‘generic’’
biologics—biosimilars and interchangeable biologic products, and provides for a twelve-year data
exclusivity period for the first approved  biological product, or reference product, against which a
biosimilar or interchangeable application is evaluated; however if pediatric  clinical trials  are performed

21

and accepted by the FDA, the twelve-year  data exclusivity period will be extended for an additional
six months. A biosimilar product is defined as one  that is highly similar to a reference product
notwithstanding minor differences in  clinically inactive components and for  which there are no clinically
meaningful differences between the biological product  and  the  reference product in terms of the safety,
purity and potency of the product. An interchangeable product  is a biosimilar product  that  may be
substituted for the reference product  without the intervention of the health care provider who
prescribed the reference product.

The biosimilar applicant must demonstrate that the  product is  biosimilar based on  data  from

(1) analytical studies showing that the biosimilar product is highly  similar  to  the reference product;
(2) animal studies (including toxicity);  and (3)  one or more clinical  trials  to  demonstrate  safety, purity
and potency in one or more appropriate  conditions  of use for  which the reference  product is approved.
In addition, the applicant must show that  the biosimilar and  reference  products have  the same
mechanism of action for the conditions of  use on the  label, route of administration, dosage  and
strength, and the production facility must meet standards designed to assure product  safety, purity and
potency.

An application for a biosimilar product may not be submitted until four years after the date on
which  the reference product was first  approved. The first approved interchangeable  biologic product
will be granted an exclusivity period of up to one year after it is first  commercially marketed, but  the
exclusivity period may be shortened under certain circumstances.

Between February 2012 and August 2014, the  FDA issued  several  draft guidance documents on

biosimilar product development. The draft guidance documents are: ‘‘Scientific Considerations in
Demonstrating Biosimilarity to a Reference Product,’’ ‘‘Quality Considerations in Demonstrating
Biosimilarity to a Reference Protein Product,’’ ‘‘Biosimilars: Questions and Answers Regarding
Implementation of the Biologics Price Competition and Innovation Act of  2009,’’ ‘‘Formal Meetings
Between the FDA and Biosimilar Biological Product Sponsors  or Applicants,’’ ‘‘Clinical Pharmacology
Data to Support a Demonstration of Biosimilarity  to  a Reference Product’’ And ‘‘Guidance  for
Industry Reference Product Exclusivity for Biological Products  Filed Under  Section 351(a)  of  the PHS
Act.’’ The guidance documents provide FDA’s current thinking on  approaches  to  demonstrating that a
proposed biological product is biosimilar  to a reference product. The FDA received  public  comments
on the draft documents and intends to  issue  final  guidance documents in  the future.  Nevertheless,  the
absence of a final guidance document does not prevent  a sponsor from  seeking licensure of  a biosimilar
under the BPCIA, and the FDA recently accepted for filing the first BLA submitted under the
biosimilar pathway.

Orphan Drug Designation

Under the Orphan Drug Act, the FDA may grant  orphan drug  designation  to  a drug intended  to

treat a rare disease or condition, which is  generally a disease or condition  that  affects fewer  than
200,000 individuals in the U.S., or more than 200,000  individuals  in the  U.S. and for which there  is no
reasonable expectation that the cost of developing and making available in the U.S. a drug for this type
of disease or condition will be recovered from sales in the  U.S.  for that  drug. Orphan drug designation
must be requested before submitting an  NDA or  BLA. After the FDA grants  orphan drug designation,
the identity of the therapeutic agent and  its potential orphan use will  be  disclosed publicly by the  FDA;
the posting will also indicate whether a drug  is no  longer designated as an orphan drug.  More than
one product candidate may receive an orphan  drug  designation  for  the same indication. Orphan drug
designation does not convey any advantage in or shorten the duration of  the regulatory review and
approval process.

If a  product that has orphan drug designation subsequently  receives the  first  FDA approval  for the

disease for which it has such designation,  the product  is entitled  to  seven years of  orphan product

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exclusivity, except in very limited circumstances. The FDA issued a final rule, effective August 12, 2013,
intended to clarify several regulatory provisions, among which was a  clarification of some of those
limited circumstances. One of the provisions makes clear  that  the FDA will  not  recognize orphan drug
exclusive approval if a sponsor fails to demonstrate upon approval  that the drug is  clinically  superior to
a previously approved drug, regardless of whether or not the approved drug was designated an orphan
drug or had orphan drug exclusivity. Thus orphan drug exclusivity also could block the approval of  one
of our products for seven years if a competitor obtains approval of  the same drug as defined  by  the
FDA and we are not able to show the  clinical  superiority of our drug or if our product candidate is
determined to be contained within the  competitor’s product  for the same indication or disease.

The FDA granted Orphan Drug designation  to  IMGN853  when used for the  treatment of ovarian

cancer. Orphan drug designation provides  us with seven years of market exclusivity that begins once
IMGN853 receives FDA marketing approval for the use  for which the orphan drug status was granted.
Later in 2014, through a separate process,  we  will  apply for orphan medicinal  product designation for
IMGN853 for the treatment of ovarian cancer  in the European Union. Orphan medicinal product
designation provides ImmunoGen with ten years of market exclusivity  that  begins  once IMGN853
receives European approval for the use for which  it was  granted.  We may pursue these designations for
other indications for other product candidates intended  for qualifying patient populations.

Expedited Review and Approval

The FDA has various programs, including Fast  Track, priority  review, and accelerated approval,
which  are intended to expedite or simplify the  process for reviewing  drugs, and/or provide  for approval
on the basis of surrogate endpoints. Even if a drug qualifies for one or more  of these  programs,  the
FDA may later decide that the drug no longer  meets  the conditions for qualification or that the  time
period for FDA review or approval will not be shortened.  Generally, drugs that may be eligible  for
these programs are those for serious  or life-threatening conditions, those  with the potential to address
unmet medical needs, and those that offer meaningful benefits over  existing treatments.  For example,
Fast Track is a process designed to facilitate the development, and expedite  the review, of drugs to
treat serious diseases and fill an unmet  medical  need. The  request may be made  at the time of IND
submission and generally no later than the pre-BLA  or pre-NDA  meeting.  The  FDA will respond
within 60 calendar days of receipt of the request. Priority review, which is  requested  at the  time of
BLA or NDA submission, is designed to give drugs  that offer  major advances in treatment or  provide a
treatment where no adequate therapy  exists  an initial  review within  six months  as compared  to  a
standard review time of ten months. Although Fast Track and priority  review do not affect the
standards for approval, the FDA will attempt to facilitate early and frequent meetings with a sponsor of
a Fast Track designated drug and expedite  review of the application for a  drug  designated for priority
review. Accelerated approval provides an earlier approval  of  drugs  to  treat serious  diseases, and  that fill
an unmet medical need based on a surrogate endpoint, which is a laboratory measurement or  physical
sign used as an indirect or substitute  measurement representing a  clinically  meaningful outcome.
Discussions with the FDA about the  feasibility of  an accelerated  approval typically begin early in  the
development of the drug in order to identify,  among  other  things, an appropriate endpoint.  As a
condition of approval, the FDA may require  that  a sponsor of  a  drug receiving accelerated  approval
perform post-marketing clinical trials to confirm the appropriateness of  the  surrogate marker trial.

In FDASIA, Congress encouraged the FDA to utilize  innovative and flexible approaches to the
assessment of products under accelerated approval. The law required the FDA  to  issue related draft
guidance within a year after the law’s enactment and also promulgate confirming regulatory changes.
The FDA published a final guidance  on  May 30, 2014,  entitled ‘‘Expedited  Programs for  Serious
Conditions—Drugs and Biologics.’’ One of the expedited programs added  by  FDASIA is that for
Breakthrough Therapy. A Breakthrough  Therapy designation is designed  to expedite the  development
and review of drugs that are intended to treat a serious  condition  where preliminary clinical evidence

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indicates that the drug may demonstrate  substantial improvement over available therapy on  a clinically
significant endpoint(s). A sponsor may  request Breakthrough Therapy designation at  the time  that  the
IND is submitted, or no later than at the  end-of-Phase II meeting.  The FDA will  respond  to  a
Breakthrough Therapy designation request within sixty days of receipt  of the request. A drug that
receives Breakthrough Therapy designation is eligible  for all fast track designation features,  intensive
guidance on an efficient drug development  program, beginning as early as Phase  I  and commitment
from the FDA involving senior managers. FDA has already  granted this designation  to  at least 60  new
drugs and seven have received approval to date.

Post-Approval Requirements

Once an approval is granted, the FDA may withdraw the  approval if compliance  with regulatory

standards is not maintained or if problems  occur after  the product reaches the market. Later  discovery
of previously  unknown problems with a product  may result  in restrictions  on the  product or even
complete withdrawal of the product from the  market.  After approval,  some types  of changes to the
approved product, such as adding new indications,  manufacturing  changes and  additional labeling
claims, are subject to further FDA review  and approval.  Drug manufacturers  and other  entities involved
in the manufacture and distribution of  approved drugs are required to register their establishments with
the FDA and certain state agencies, and  are  subject to periodic unannounced inspections by the FDA
and certain state agencies for compliance  with cGMP and other  laws and regulations. We rely, and
expect to continue to rely, on third parties for the production of clinical and commercial quantities of
our  products. Future inspections by the  FDA  and other regulatory  agencies may identify compliance
issues at the facilities of our contract manufacturers  that may disrupt production  or distribution, or
require substantial resources to correct.

Any drug products manufactured or  distributed  by us  pursuant  to  FDA approvals  are subject to

continuing regulation by the FDA, including, among other things,  record-keeping requirements,
reporting of adverse experiences with the  drug, providing the FDA with  updated safety and efficacy
information, drug sampling and distribution requirements, complying with certain  electronic records and
signature requirements, and complying with  FDA promotion and advertising requirements. FDA strictly
regulates labeling, advertising, promotion  and other types of information  on products that are placed
on the market. Drugs may be promoted only for  the approved indications and in accordance  with the
provisions of the approved label.

From time to time, legislation is drafted,  introduced  and  passed in  Congress that could significantly

change the statutory provisions governing the approval,  manufacturing  and  marketing of  products
regulated by the FDA. It is impossible to predict whether further legislative changes will be enacted, or
FDA regulations, guidance or interpretations changed  or what the impact of such  changes, if  any, may
be.

Foreign Regulation

In addition to regulations in the U.S.,  we will be subject  to  a  variety of foreign regulations
governing clinical trials and commercial sales and  distribution of our products. Whether  or not we
obtain FDA approval for a product, we  must obtain approval  by the comparable  regulatory authorities
of foreign countries or economic areas,  such  as the European Union,  before we may commence  clinical
trials or market products in those countries or areas. The approval process  and requirements governing
the conduct of clinical trials, product licensing, pricing and reimbursement vary greatly from place  to
place, and the time may be longer or shorter than that required for FDA approval.

Under European Union regulatory systems, a company may submit marketing authorization
applications either under a centralized  or  decentralized  procedure. The centralized procedure, which is
compulsory for medicinal products produced by biotechnology  or those medicinal  products containing

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new active substances for specific indications  such as the  treatment of  AIDS, cancer, neurodegenerative
disorders, diabetes, viral diseases and  designated orphan medicines, and optional for other medicines
which  are highly innovative. Under the  centralized procedure,  a marketing application is  submitted to
the European Medicines Agency where it  will  be  evaluated by  the Committee  for Medicinal Products
for Human Use and a favorable opinion  typically results in the  grant by  the European Commission  of a
single marketing authorization that is valid for  all  European Union member states  within 67  days of
receipt of the opinion. The initial marketing  authorization is valid for  five  years,  but once  renewed is
usually valid for an unlimited period.  The  decentralized procedure provides for approval by one or
more ‘‘concerned’’ member states based on an  assessment of an  application  performed by one  member
state, known as the ‘‘reference’’ member state.  Under the  decentralized  approval procedure,  an
applicant submits an application, or dossier,  and related materials to the  reference member state and
concerned member states. The reference member state  prepares a draft assessment and drafts  of  the
related materials within 120 days after receipt of  a valid application. Within  90 days of  receiving the
reference member state’s assessment  report, each concerned member  state must decide whether to
approve the assessment report and related materials.  If a member state does  not  recognize the
marketing authorization, the disputed  points are  eventually referred to the European Commission,
whose decision is binding on all member  states.

As in the U.S., we may apply for designation of a product as  an  orphan drug  for the  treatment of

a specific indication in the European  Union  before  the application for  marketing  authorization is made.
Orphan  drugs in Europe enjoy economic and marketing  benefits, including up to 10 years of market
exclusivity for the approved indication  unless another applicant can show  that its product is safer, more
effective or otherwise clinically superior to the orphan-designated  product.

Reimbursement

Sales of pharmaceutical products depend in  significant part on the availability  of  third-party

reimbursement. Third-party payors include  government  healthcare programs such  as Medicare,
managed care providers, private health  insurers and other organizations. We anticipate  third-party
payors will provide reimbursement for  our products.  However, these third-party payors are increasingly
challenging the price and examining the cost-effectiveness  of medical  products and services. In addition,
significant uncertainty exists as to the reimbursement  status of  newly  approved healthcare  products. We
may need to conduct expensive pharmacoeconomic studies in order to demonstrate the
cost-effectiveness of our products. Our  product  candidates may not be considered cost-effective. It is
time consuming and expensive for us  to  seek reimbursement from third-party payors. Reimbursement
may not be available or sufficient to allow us to sell  our  products on a competitive and profitable basis.

Medicare is a federal healthcare program administered by the federal government that covers
individuals age 65 and over as well as some individuals with certain disabilities. Drugs may be covered
under one or more sections of Medicare depending on  the nature of the drug and the conditions
associated with and site of administration. For  example,  under Part D, Medicare beneficiaries may
enroll in prescription drug plans offered  by  private entities which provide coverage of  outpatient
prescription drugs. Part D plans include both stand- alone prescription drug  benefit plans  and
prescription drug coverage as a supplement  to  Medicare Advantage plans. Unlike Medicare Part A  and
B, Part D coverage is not standardized.  Part  D prescription drug  plan sponsors are not required  to  pay
for all covered Part D drugs, and each drug plan can develop its  own drug formulary that identifies
which  drugs it will  cover and at what  tier  or level.

Medicare Part B covers most injectable  drugs  given in  an in-patient  setting and some drugs
administered by a  licensed medical provider  in hospital outpatient  departments and  doctors’  offices.
Medicare Part B is administered by Medicare  Administrative Contractors, which generally have the
responsibility of making coverage decisions. Subject to certain payment adjustments  and limits,
Medicare generally pays for a Part B covered drug  based on a percentage of manufacturer-reported

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average sales price which is regularly  updated. We believe that  most  of our drugs, when approved, will
be subject to the Medicare Part B rules.

The American Recovery and Reinvestment Act of 2009 provides funding for the federal

government to compare the effectiveness  of different treatments for the same illness. A  plan for this
research will be developed by the Department  of  Health and Human  Services, the Agency for
Healthcare Research and Quality and the  National Institutes for Health, and periodic reports on the
status of the research and related expenditures will be made to Congress. Although the results of the
comparative effectiveness studies are not intended to mandate coverage policies for public or private
payors, it is not clear what effect, if any, the  research will  have on the sales of our product  candidates,
if any such product or the condition  that it is  intended to treat is  the subject of  a study. It  is also
possible that comparative effectiveness  research demonstrating benefits in  a competitor’s product could
adversely affect the sales of our product  candidates. If third-party payors  do not consider our products
to be cost- effective compared to other available therapies, they may not cover our products after
approval as a benefit under their plans  or, if  they  do,  the level of  payment may not be sufficient to
allow us to sell our products on a profitable basis.

We  expect that there will continue to  be  a number of federal  and state proposals  to  implement

governmental pricing controls and limit the growth of healthcare costs, including the cost of
prescription drugs. For example, the Patient  Protection and Affordable Care Act,  as amended  by  the
Health Care and Education Affordability  Reconciliation Act  of  2010 (collectively, ACA) enacted in
March 2010, is expected to have a significant impact on  the health care industry. ACA is expected  to
expand coverage for the uninsured while  at the  same time  containing overall healthcare costs. With
regard to pharmaceutical products, among  other things,  ACA is expected to expand and increase
industry rebates for drugs covered under Medicaid  programs and  make changes  to  the coverage
requirements under the Medicare Part  D program.  We cannot  predict  the impact of ACA on
pharmaceutical companies as many of  the ACA reforms  require the promulgation  of  detailed
regulations implementing the statutory provisions which has not yet occurred. In  addition,  although the
United States Supreme Court upheld the  constitutionality of most of the  ACA,  some states have stated
their intentions to not implement certain  sections of ACA and  some members of Congress are still
working to repeal ACA. These challenges add to the uncertainty of the changes enacted as part of
ACA.

In addition, in some foreign countries, the  proposed pricing for a drug must be approved before  it

may be lawfully marketed. The requirements governing drug pricing vary widely from country to
country. For example, the European  Union  provides options for its member states to restrict  the range
of medicinal products for which their national  health insurance  systems  provide reimbursement and to
control the prices of medicinal products for human  use. A  member state may  approve a specific price
for the medicinal product or it may instead adopt a  system of direct  or indirect controls on  the
profitability of the company placing the  medicinal product  on the  market.  There can be no assurance
that any country that has price controls or reimbursement limitations for pharmaceutical products  will
allow favorable reimbursement and pricing arrangements for  any of our products. Historically, products
launched in the European Union do  not  follow price structures of  the  U.S. and generally tend to be
significantly lower.

Research and Development Spending

During  each of the three years ended  June 30, 2014,  2013 and  2012, we spent approximately
$107.0 million, $87.1 million and $69.2  million, respectively, on research  and development  activities.

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Raw Materials and Manufacturing

We  procure certain raw material components of finished conjugate,  including antibodies,  cytotoxic
agents, and linker, for ourselves and  on  behalf of our collaborators. In order to meet our commitments
to our collaborators as well as our own  needs, we  are required to enter into  agreements with
third parties to produce these components  well in  advance  of  our production  needs.  Our principal
suppliers for these components include Abbvie  Inc., Boehringer  Ingelheim, Cytovance Biologics  LLC,
SAFC, Inc., Carbogen Amcis and Societ`a Italiana Corticosteroidi S.r.l.

In addition, we operate a conjugate manufacturing facility. A portion  of  the cost  of operating this

facility, including the cost of manufacturing personnel, is incurred to conjugate material on behalf of
our  collaborators for which we receive  payments based on the number of batches of preclinical and
clinical materials produced on their behalf.  Over the past few years, we have  expanded and upgraded
the capabilities of  our manufacturing facility.

Employees

As of June 30, 2014, we had 307 full-time employees,  of  whom 262 were  engaged  in research and

development activities. Of the 262 research and development employees, 132 research and development
employees hold post-graduate degrees,  of which 57 hold  Ph.D. degrees and seven hold M.D. degrees.
We  consider our relations with our employees  to  be  good. None of our employees is  covered by a
collective bargaining agreement.

We  have entered into confidentiality agreements with all  of  our employees, members of our board
of directors and consultants. Further, we have  entered into assignment of invention agreements with all
of our employees.

Third-Party Trademarks

Herceptin and Kadcyla are registered trademarks of Genentech. Rituxan  is a registered trademark

of Biogen Idec Inc. Probody is a trademark of CytomX Therapeutics, Inc.

Item 1A. Risk Factors

THE RISKS AND UNCERTAINTIES  DESCRIBED BELOW  ARE  THOSE THAT  WE CURRENTLY
BELIEVE MAY MATERIALLY AFFECT OUR COMPANY.  ADDITIONAL RISKS  AND
UNCERTAINTIES THAT WE ARE UNAWARE OF  OR THAT  WE CURRENTLY DEEM
IMMATERIAL ALSO MAY BECOME IMPORTANT FACTORS THAT AFFECT OUR  COMPANY.

We have a history of operating losses and expect to incur significant  additional operating losses.

We  have generated operating losses since our inception. As  of June 30, 2014,  we had an

accumulated deficit of $648.1 million.  For  the years ended June 30, 2014,  2013, and 2012, we generated
losses of $71.4 million, $72.8 million  and $73.3  million,  respectively. We  may never be profitable. We
expect to incur substantial additional  operating expenses over the  next several years as  our research,
development, preclinical testing, clinical trials and collaborator support activities continue. We intend to
continue to invest significantly in our  product candidates.  Further, we expect to invest some  of  our
resources to support our existing collaborators  as they  work  to  develop, test and commercialize ADC
compounds. We or our collaborators  may  encounter technological or regulatory difficulties as  part of
this  development and commercialization process  that  we cannot overcome  or remedy. We  may also
incur substantial marketing and other costs in the  future if we decide  to  establish marketing and  sales
capabilities to commercialize our product  candidates. Our  revenues to date have been primarily  from
upfront and milestone payments, research and  development support and clinical materials
reimbursement from our collaborative  partners and increasingly from royalties received from the
commercial sales of Kadcyla. We do  not expect  to  generate revenues from  the commercial sale of our

27

internal product candidates in the near future, and we may never  generate  revenues from  the
commercial sale of internal products.  Even  if we do successfully develop products that can be marketed
and sold commercially, we will need to generate significant revenues from those  products to achieve
and maintain profitability. Even if we  do become  profitable, we may  not  be  able to sustain or increase
profitability on a quarterly or annual  basis.

If we are unable to obtain additional  funding when needed, we may have to delay  or  scale back some
of our programs or grant rights to third parties to  develop and  market our  product candidates.

We  will continue to expend substantial  resources developing new and existing  product candidates,

including costs associated with research  and development, acquiring new technologies,  conducting
preclinical studies and clinical trials, obtaining regulatory approvals and manufacturing products as well
as providing certain support to our collaborators  in the development of their  products. We believe that
our  current working capital and expected  future payments from our existing  collaboration  arrangements
will be sufficient to meet our current and projected  operating and  capital requirements partway through
fiscal 2016. However, we cannot provide assurance that such collaborative  agreement funding will,  in
fact, be  received. Should such future collaborator payments not be earned  and paid  as currently
anticipated, we expect we could seek  additional funding from other sources. We may  need additional
financing sooner due to a number of other factors as well, including:

(cid:127) if  either we incur higher than expected  costs or  we or  any of our  collaborators experience slower
than expected progress in developing product candidates and obtaining regulatory approvals;

(cid:127) acquisition of technologies and other  business opportunities that  require financial commitments.

Additional funding may not be available to us on favorable terms, or  at all. We may raise

additional funds through public or private  financings, collaborative arrangements or other
arrangements. Debt financing, if available, may involve covenants that could restrict our business
activities. If we are unable to raise additional funds through equity or  debt financing when needed, we
may be required to delay, scale back or eliminate expenditures for some of our development  programs
or grant rights to develop and market  product candidates  that we would  otherwise prefer to internally
develop and market. If we are required  to  grant such rights, the ultimate value  of  these  product
candidates to us may be reduced.

If our ADC technology does not produce  safe, effective and  commercially viable products,  our  business
will be severely harmed.

Our ADC technology yields novel product candidates for the  treatment of cancer. To date,  only
one ADC product candidate has obtained marketing approval. Our  ADC product  candidates and/or  our
collaborators’ ADC product candidates may not prove to be  safe, effective  or commercially viable
treatments for cancer and our ADC technology  may not result in any future meaningful  benefits to us
or for our current or potential collaborative partners. Furthermore, we  are aware of only two other
compounds that are a conjugate of an antibody and a cytotoxic  small molecule that have obtained
marketing approval by the FDA and are based on technology similar  to  our ADC technology.  One of
these products was later taken off the market by its  owner  due to toxicity  concerns. If  our  ADC
technology fails to generate product candidates that are  safe, effective and commercially  viable
treatments for cancer or fail to obtain  FDA approval, our  business will  be severely harmed.

Clinical trials for our and our collaborative partners’ product  candidates will be lengthy  and expensive
and their outcome is uncertain.

Before obtaining regulatory approval  for the  commercial sale  of  any product candidates,  we and
our  collaborative partners must demonstrate  through clinical testing that our product candidates  are
safe and effective for use in humans.  Conducting  clinical trials  is a time-consuming, expensive and

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uncertain process and typically requires  years  to  complete. In  our industry,  the results from  preclinical
studies and early clinical trials often are not predictive  of  results obtained in later-stage clinical trials.
Some compounds that have shown promising results in preclinical  studies or  early clinical trials
subsequently fail to establish sufficient  safety and  efficacy data necessary  to obtain regulatory approval.
At any time during the clinical trials, we,  our collaborative  partners,  or the FDA might  delay or halt
any clinical trials of our product candidates for  various reasons,  including:

(cid:127) occurrence of unacceptable toxicities or side effects;

(cid:127) ineffectiveness of the product candidate;

(cid:127) insufficient drug supply;

(cid:127) negative or inconclusive results from the clinical trials,  or  results that necessitate  additional

studies  or clinical trials;

(cid:127) delays in obtaining or maintaining required approvals from institutions,  review boards  or other

reviewing entities at clinical sites;

(cid:127) delays in patient enrollment;

(cid:127) insufficient funding or a reprioritization of financial or  other resources; or

(cid:127) other reasons that are internal to the businesses of our collaborative partners, which  they may

not share with us.

Any failure or substantial delay in successfully completing  clinical  trials  and  obtaining  regulatory
approval for our product candidates or  our collaborative partners’ product candidates could severely
harm our business.

We and our collaborative partners are  subject to  extensive government regulations and  we and  our
collaborative  partners may not be able  to  obtain necessary regulatory approvals.

We  and our collaborative partners may not receive  the regulatory  approvals necessary to

commercialize our product candidates, which would cause  our business to be severely harmed.
Pharmaceutical product candidates, including those in development  by us  and our collaborative
partners, are subject to extensive and rigorous government regulation.  The FDA regulates, among other
things, the development, testing, manufacture, safety,  record-keeping,  labeling, storage, approval,
advertising, promotion, sale and distribution  of  pharmaceutical products. If  our  potential  products or
our  collaborators’ potential products are marketed  abroad, they will also  be  subject to extensive
regulation by foreign governments. The  regulatory review and approval process, which includes
preclinical studies and clinical trials of  each  product candidate, is lengthy,  complex, expensive and
uncertain. Securing FDA approval requires  the submission of extensive preclinical and clinical data and
supporting information to the FDA for  each indication to establish the  product candidate’s safety and
efficacy. Data obtained from preclinical studies and clinical trials are susceptible  to  varying
interpretation, which may delay, limit or prevent regulatory approval.  The approval process may take
many  years to complete and may involve  ongoing requirements for post-marketing studies. Any FDA or
other regulatory approvals of our or  our  collaborative partners’  product candidates, once obtained, may
be withdrawn. The effect of government regulation may be to:

(cid:127) delay marketing of potential products for a considerable period of time;

(cid:127) limit the indicated uses for which potential products  may  be  marketed;

(cid:127) impose costly requirements on our  activities; and

(cid:127) place us at a competitive disadvantage to other pharmaceutical and biotechnology  companies.

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We  may encounter delays or rejections in the  regulatory approval process  because of additional
government regulation from future legislation or administrative action  or changes in  FDA policy during
the period of product development, clinical trials and  FDA regulatory review.  Failure to comply with
FDA or other applicable regulatory requirements may result  in criminal prosecution,  civil  penalties,
recall or seizure of products, total or  partial suspension of production or  injunction, as well as  other
regulatory action against our product candidates or  us. Outside the  U.S., our ability to market a
product  is contingent upon receiving clearances  from the appropriate regulatory authorities. The
foreign regulatory  approval process includes similar  risks to those associated with the FDA approval
process. In addition, we are, or may become,  subject to various  federal, state and  local laws, regulations
and recommendations relating to safe working conditions,  laboratory and manufacturing practices, the
experimental use of animals and the use and disposal  of  hazardous substances, including radioactive
compounds and infectious disease agents, used in  connection with  our research  work. If  we fail to
comply  with the laws and regulations pertaining to our business, we  may be subject to sanctions,
including the temporary or permanent suspension of operations,  product recalls, marketing restrictions
and civil and criminal penalties.

Our and our collaborative partners’ product candidates will remain subject  to ongoing regulatory
review even if they receive marketing  approval. If we  or our  collaborative partners fail to comply with
continuing regulations, these approvals  could be lost  and the  sale  of our or our collaborative partners’
products could be suspended.

Even if we or our collaborative partners receive  regulatory approval to market  a particular product

candidate, the approval could be conditioned  on us  or our  collaborative  partners conducting  costly
post-approval studies or could limit the  indicated uses included in product labeling.  Moreover, the
product  may later cause adverse effects that limit or  prevent its widespread use, force us  or our
collaborative partners to withdraw it from  the  market  or impede  or  delay our or  our collaborative
partners’ ability to obtain regulatory  approvals in  additional countries.  In addition, the  manufacturer of
the product and its facilities will continue  to  be  subject to FDA  review and  periodic inspections to
ensure adherence to applicable regulations. After  receiving marketing approval, the manufacturing,
labeling, packaging, adverse event reporting,  storage, advertising, promotion and  record-keeping related
to the product remain subject to extensive regulatory  requirements.  We  or our collaborative  partners
may be slow to adapt, or we or our collaborative partners may never adapt,  to  changes in existing
regulatory requirements or adoption  of  new regulatory requirements.

If we  or our collaborative partners fail to comply with  the regulatory  requirements of the  FDA and
other applicable U.S. and foreign regulatory authorities, or if  previously unknown problems with our  or
our  partners’ products, manufacturers or  manufacturing processes are discovered, we could be subject
to administrative or judicially imposed sanctions, including:

(cid:127) restrictions on the products, manufacturers or manufacturing  processes;

(cid:127) warning letters;

(cid:127) civil or criminal penalties;

(cid:127) fines;

(cid:127) injunctions;

(cid:127) product seizures or detentions;

(cid:127) import bans;

(cid:127) voluntary or mandatory product recalls and publicity requirements;

(cid:127) suspension or withdrawal of regulatory approvals;

30

(cid:127) total or partial suspension of production;  and

(cid:127) refusal to approve pending applications for marketing approval  of  new  drugs or supplements to

approved applications.

Any one of these could have a material adverse  effect on  our business or  financial condition.

If our collaborative partners fail to perform their obligations under our agreements with them,  or
determine not to continue with clinical trials for  particular product candidates, our business  could be
severely impacted.

Our strategy for the development and commercialization of our product candidates depends, in
large part, upon the formation and maintenance of collaborative arrangements. Collaborations provide
an opportunity for us to:

(cid:127) generate cash flow and revenue;

(cid:127) fund some of the costs associated with our internal research and development,  preclinical

testing, clinical trials and manufacturing;

(cid:127) seek and obtain regulatory approvals  faster than we  could  on our own;

(cid:127) successfully commercialize existing  and future  product candidates; and

(cid:127) secure access to targets which, due to intellectual property restrictions, would otherwise be

unavailable to our technology.

If we  fail to secure or maintain successful  collaborative  arrangements, the  development and
marketing of compounds that use our technology may be delayed, scaled back or otherwise  may not
occur. In addition, we may be unable to negotiate other collaborative arrangements  or, if  necessary,
modify  our existing arrangements on acceptable  terms. We cannot control the  amount  and timing  of
resources our collaborative partners may  devote to our product candidates. Our  collaborative partners
may separately pursue competing product candidates, therapeutic approaches or  technologies to
develop treatments for the diseases targeted  by us  or our collaborative efforts, or  may decide,  for
reasons not known to us, to discontinue  development of product candidates under our agreements  with
them. Any of our collaborative partners  may  slow or discontinue the  development of a product
candidate covered by a collaborative arrangement for reasons that  can include, but are not limited to:

(cid:127) a change in the collaborative partner’s strategic focus as a  result of merger, management

changes, adverse business events, or other causes;

(cid:127) a change in the priority of the product candidate relative to other programs in the collaborator’s

pipeline;

(cid:127) a reassessment of the patent situation related to the compound  or  its target;

(cid:127) a change in the anticipated competition for the product  candidate;

(cid:127) preclinical studies and clinical trial  results; and

(cid:127) a reduction in the financial resources  the collaborator can  or  is willing to apply to the

development of new compounds.

Even if our collaborative partners continue  their  collaborative arrangements with  us, they  may

nevertheless determine not to actively  pursue the  development or commercialization of any resulting
products. Also, our collaborative partners may fail to perform their obligations under  the collaborative
agreements or may be slow in performing their obligations. Our collaborative partners can terminate
our  collaborative agreements under certain conditions. The decision to advance a  product that is
covered by a collaborative agreement through clinical trials and ultimately to commercialization is in

31

the discretion of our collaborative partners. If  any  collaborative partner were to terminate  or breach
our  agreements, fail to complete its obligations to us in a  timely manner, or decide to discontinue its
development of a product candidate, our  anticipated revenue from the agreement  and from  the
development and commercialization of the  products would  be  severely limited. If  we are  not  able to
establish additional collaborations or  any  or all of  our  existing collaborations are terminated and we are
not able to enter into alternative collaborations on acceptable  terms, or at all, our continued
development, manufacture and commercialization  of  our  product candidates  could  be  delayed or  scaled
back as  we may not have the funds or  capability to continue these activities. If our  collaborators  fail to
successfully develop and commercialize ADC  compounds, our business prospects  would be severely
harmed.

We depend on a small number of collaborators for a substantial portion  of our revenue.  The  loss of, or
a material reduction in activity by, any  one of these  collaborators could result in a substantial decline
in our revenue.

We  have and will continue to have collaborations  with a limited  number of companies. As a  result,

our  financial performance depends on the  efforts and overall success of these companies. Also, the
failure of any one of our collaborative  partners  to  perform its obligations  under its agreement with us,
including making any royalty, milestone or  other payments to us,  could have an adverse effect on our
financial condition. Further, any material  reduction by any one of our collaborative partners in its level
of commitment of resources, funding, personnel,  and  interest in continued development under its
agreement with us could have an adverse  effect  on our financial condition. Also, if consolidation trends
in the healthcare industry continue, the number  of  our  potential  collaborators could decrease, which
could have an adverse impact on our development efforts.  If a present or  future collaborator of ours
were to be involved in a business combination, the collaborator’s continued pursuit  and emphasis on
our  product development program could  be delayed,  diminished or terminated.

Our royalty revenues will likely fluctuate  and  may  become  more  difficult to  forecast in future periods.

On February 22, 2013, the FDA granted marketing approval to Kadcyla. Kadcyla was developed by
Roche, through its Genentech unit, under a license we  granted in May 2000,  pursuant  to  which we are
entitled to receive milestone payments plus royalties  on commercial sales of Kadcyla. Roche and its
affiliates have also received marketing approval of Kadcyla  in Europe and Japan along with  various
other countries. As a result of the start of  commercialization  of Kadcyla in  the U.S.  and elsewhere, we
expect an increasing proportion of our  revenue and operating results  to  derive from  royalties based  on
the commercial sales of Kadcyla. These royalty  revenues may fluctuate considerably  because they
depend  upon, among other things, the  rate of growth of sales of  Kadcyla as well  as the mix of U.S.-
based sales and ex-U.S.-based sales and  our valid patent claims. Kadcyla is currently the only product
with respect to which we are entitled  to  receive royalties  that  has received marketing approval.

The Roche agreement provides for separate tiered royalty structures with  respect to sales in two
territories: 1) the U.S. and 2) the rest  of the world. The royalty rate Roche  must  pay on  sales in each
of these  two territories increases on  incremental sales in  a given calendar year in  the applicable
territory above certain net sales thresholds. As a  result of the  tiered  royalty structure,  Roche’s average
royalty rate should increase over the course  of  a calendar year as more  Kadcyla is  sold in that year.
However, we recognize royalty revenues  in the quarter  in which  they are received,  which are  based on
Kadcyla sales in the preceding quarter.  Accordingly, we anticipate that the average royalty rate for
payments we receive from Roche will generally  increase between the second  quarter  of  one calendar
year (our fourth fiscal quarter) and the  first calendar quarter  of  the next (our  third  quarter  of  the next
fiscal year).

32

Royalty rates under our license agreements  with  our  collaborators may vary over the  royalty  term
depending on our  intellectual property  rights and the presence of competing  products.

Most of our license agreements with our collaborators  provide that the royalty rates  are subject to

downward adjustment in the absence  of  ImmunoGen patent rights covering various aspects of  the
manufacture, use or sale of the products developed  under such licenses,  or in the presence of
competition from certain third-party  products. For example, we  expect  the royalty rate for  Sanofi’s
SAR650984 anti-CD38 naked antibody compound to be reduced to low single digits because of
(1) competitor development of alternative  anti-CD38 antibody compounds,  and (2) the lack of
ImmunoGen patent rights covering SAR650984, since our ADC-related patent rights do not pertain to
the compound and our SAR650984-specific patent rights  were assigned to Sanofi  under the terms of
the applicable license.

We depend on our collaborative partners for the  determination of royalty payments.  We may  not be
able to detect errors and payment calculations may  call for  retroactive adjustments.

The royalty payments we receive are determined  by  our collaborative partners based on their

reported net sales. Each collaborative  partner’s calculation of the royalty  payments is subject to and
dependent upon the adequacy and accuracy  of its  sales  and accounting  functions, and errors may occur
from time to time in the calculations  made by a collaborative partner. Our agreement with  Genentech
provides us the right to audit the calculations and  sales  data for the associated royalty  payments related
to sales of Kadcyla; however, such audits  may  occur many months following our recognition of the
royalty revenue, may require us to adjust  our royalty revenues in  later periods and generally require
expense on our part.

If our collaborative partners’ requirements for  clinical  materials to be manufactured by us are
significantly lower than we have estimated, our financial results  and  condition  could be  adversely
affected.

We  procure certain components of finished conjugate, including DM1,  DM4, and linker, on  behalf
of several of our collaborators. In order  to meet our commitments to our collaborative partners, we are
required to enter into agreements with third parties to produce  these components well in  advance  of
our  production of clinical materials on  behalf  of  our  collaborative partners. If our collaborative partners
do not require as much clinical material  as  we have  contracted  to  produce and we are unable to use
these materials for our own products,  we  may not be able to recover our  investment in  these
components and we may suffer losses. Collaborators have  discontinued development of  product
candidates in the past and in the periods  subsequent to these discontinuations, we had significantly
reduced demand for DM1 and DM4  which adversely  impacted  our financial  results.

In addition, we operate a conjugate manufacturing facility. A portion  of  the cost  of operating this
facility, including the cost of manufacturing personnel, is reimbursed by our  collaborators  based on  the
number of batches of preclinical and  clinical materials produced on  their behalf. If we produce  fewer
batches  of clinical materials for our collaborators, a  smaller amount  of the cost  of  operating the
conjugate manufacturing facility will  be  charged to our collaborative partners and our financial
condition could be adversely affected.

33

If our product requirements for clinical trials are significantly higher  than  we estimated, the inability
to procure additional antibody or fill/finish  services in  a timely manner could  impair our ability  to
initiate or advance our clinical trials.

We  rely  on third-party suppliers to manufacture antibodies  used  in our own proprietary

compounds. Due to the specific nature of  the antibody and availability of production capacity, there  is
significant lead time required by these  suppliers to provide us with  the needed materials. If our
antibody  requirements for clinical materials to be manufactured are  significantly  higher than  we
estimated, we may not be able to readily procure  additional antibody which would impair our ability to
advance  our clinical trials currently in  process or initiate  additional  trials.  We  also rely on  third parties
to convert the bulk drug substance we  manufacture  into  filled and finished vials of drug product  for
clinical use. Unanticipated difficulties or delays in  the fill/finish process could impair our  ability to
advance  our clinical trials currently in  process or initiate  additional  trials.  There can  be  no assurance
that we will not have supply problems  that  could  delay or  stop our clinical trials or otherwise could
have a material adverse effect on our  business.

We currently rely on one third-party manufacturer with commercial production  experience  to produce
our cell-killing agents, DM1 and DM4.

We  rely  on a third-party supplier to manufacture one of the  materials used to make  ADC
compounds. Our cell-killing agents DM1  and  DM4, collectively DMx, are manufactured  from a
precursor, ansamitocin P3. We currently  use a single supplier, Societ´a Italiana Corticosteroidi S.r.l.,that
converts ansamitocin P3 to DMx. Any delay  or interruption in our supply  of  DMx could lead  to  a delay
or interruption in our manufacturing  operations, preclinical studies and clinical trials of our product
candidates and our collaborators’ product candidates, which could  negatively affect  our business.

We may be delayed or unable to establish the  manufacturing capabilities necessary to develop  and
commercialize our and our collaborative  partners’  potential  products.

Currently, we have one conjugate manufacturing facility  that  we use to manufacture conjugated

compounds for us and several of our collaborative partners  for preclinical studies and early-stage
clinical testing. Several of our partners  have contracted  for separate, large-scale manufacturing  capacity
to make materials to support potential  future  commercialization of their ADC compounds. We do not
currently have the manufacturing capacity needed  to  make our product candidates for commercial sale.
In addition, our manufacturing capacity may be insufficient to complete all clinical trials contemplated
by us and our collaborative partners over time. We  intend to rely in part  on third-party contract
manufacturers to produce sufficiently  large quantities of  drug materials  that are and  will be needed for
later-stage clinical trials and commercialization  of our potential products. We  are currently in the
process of developing relationships with third-party manufacturers that we believe  will  be  necessary  to
continue the development of our product  candidates. Third-party manufacturers may  not  be  able to
meet our needs with respect to timing, quantity  or quality  of materials. If  we are  unable to contract  for
a sufficient supply of needed materials on  acceptable terms, or if we should encounter delays or
difficulties in our relationships with manufacturers,  our  clinical trials may  be  delayed, thereby delaying
the submission of product candidates  for regulatory approval  and the market introduction and
subsequent commercialization of our  potential products.  Any such  delays may  lower our revenues  and
potential profitability.

We have one conjugate manufacturing  facility and any  prolonged and  significant disruption at that
facility could impair our ability to manufacture our and our collaborative partners’ product  candidates
for clinical testing.

Currently, in certain cases, we are contractually obligated  to manufacture  Phase I and non-pivotal
Phase II clinical products for companies licensing our ADC technology.  We manufacture this material,

34

as well as material for our own product  candidates, in  our conjugate manufacturing  facility.  We have
only one such manufacturing facility in  which we can  manufacture clinical products.  Our current
manufacturing facility contains highly specialized  equipment and utilizes complex  production  processes
developed over a number of years that  would be difficult, time-consuming and costly  to  duplicate.  Any
prolonged disruption in the operations  of  our manufacturing  facility would have a  significant negative
impact on our ability to manufacture  products for clinical testing on our  own and  would cause us to
seek additional third-party manufacturing contracts, thereby  increasing  our  development costs.  Even
though we carry business interruption  insurance policies, we  may suffer losses as a result of business
interruptions  that exceed the coverage available  or any losses which may be  excluded under  our
insurance policies. Certain events, such as natural disasters, fire, political disturbances, sabotage or
business accidents, which could impact  our current or future facilities, could have a  significant negative
impact on our operations by disrupting  our product  development efforts until  such time as we are able
to repair our facility or put in place third-party  contract manufacturers to  assume this  manufacturing
role.

Unfavorable pricing regulations, third-party reimbursement practices or healthcare  reform initiatives
applicable to our product candidates could limit our potential product revenue.

Antibody-based anticancer products are often much more costly to produce than traditional
chemotherapeutics and tend to have significantly higher prices. Factors that help justify  the price
include the high mortality associated with  many types  of  cancer and the need for  more and  better
treatment options.

Regulations governing drug pricing and reimbursement vary widely  from  country to country. Some

countries require approval of the sales price of a  drug before  it can be marketed. Some countries
restrict the physicians that can authorize the  use of more  expensive medications.  Some  countries
establish treatment guidelines to help  limit the  use of more  expensive  therapeutics and  the pool of
patients that receive them. In some countries, including  the U.S., third-party payers  frequently  seek
discounts from list prices and are increasingly challenging the  prices charged  for medical products.
Because our product candidates are  in  the development stage, we do not know the level of
reimbursement, if any, we will receive  for  any products that we are able to successfully develop. If  the
reimbursement for any of our product candidates is inadequate in light of our development and other
costs, our ability to achieve profitability would be affected.

We  believe that the efforts of governments and third-party  payors to contain or reduce the cost  of

healthcare will continue to affect the  business and financial condition of pharmaceutical and
biopharmaceutical companies. A number  of  legislative  and regulatory proposals to change the
healthcare system in the U.S. and other major  healthcare markets have  been proposed and  adopted in
recent years. For example, the U.S. Congress  enacted a limited prescription drug benefit for Medicare
recipients as part of the Medicare Prescription Drug, Improvement and Modernization Act of 2003.
While the program established by this  statute may  increase demand for any products  that  we are  able
to successfully develop, if we participate in this program, our  prices will be  negotiated with drug
procurement organizations for Medicare  beneficiaries and are likely  to  be lower than prices we might
otherwise obtain. Non-Medicare third-party  drug procurement organizations  may also base the  price
they are willing to pay on the rate paid  by drug procurement organizations for  Medicare beneficiaries.
The PPACA will also require discounts  under the  Medicare  drug  benefit program and  increased  rebates
on drugs covered by Medicaid. In addition, the PPACA  imposes  an annual fee,  which will increase
annually, on sales by branded pharmaceutical manufacturers. The financial impact of these discounts,
increased rebates and fees and the other provisions of the PPACA on our business is unclear  and there
can be no assurance that our business will not be materially  adversely affected by the PPACA.  In
addition, ongoing initiatives in the U.S.  have  increased and will continue  to  increase pressure on  drug

35

pricing. The announcement or adoption  of any such initiative could have  an adverse effect on  potential
revenues from any product candidate that  we may successfully develop.

We may be unable to establish sales  and  marketing  capabilities  necessary  to successfully
commercialize our potential products.

We  currently have no direct sales or marketing capabilities. We may  rely on third parties to market
and sell most of our primary product candidates or we may outlicense these products  prior to the time
when these capabilities are needed. If we  decide to market our potential products through a  direct
sales force, we would need either to  hire a sales force with  expertise in  pharmaceutical sales or to
contract with a third party to provide a sales force  which meets  our needs.  We may  be  unable to
establish marketing, sales and distribution capabilities necessary to commercialize and gain market
acceptance for our potential products and be competitive. In addition, co-promotion  or other marketing
arrangements with third parties to commercialize potential products could significantly limit the
revenues we derive from these potential  products, and these  third parties may fail to commercialize our
compounds successfully.

If our product candidates or those of  our  collaborative partners  do not gain market acceptance, our
business  will suffer.

Even if clinical trials demonstrate the safety and efficacy  of  our and  our collaborative partners’

product  candidates and the necessary  regulatory approvals are obtained, our and our collaborative
partners’ products may not gain market  acceptance among physicians, patients, healthcare  payors and
other members of the medical community. The degree of market acceptance of  any products that we  or
our  collaborative partners develop will depend on a number of factors, including:

(cid:127) their level of clinical efficacy and safety;

(cid:127) their advantage over alternative treatment  methods;

(cid:127) our/the marketer’s and our collaborative partners’ ability to gain acceptable  reimbursement and

the reimbursement policies of government and third-party  payors; and

(cid:127) the quality of the distribution capabilities of  the party(ies) responsible  to market and  distribute

the product(s).

Physicians may not prescribe any of our  future products until such time as clinical  data  or other
factors demonstrate the safety and efficacy  of those  products as compared to conventional drugs  and
other treatments. Even if the clinical  safety and efficacy of therapies using our products is  established,
physicians may elect not to recommend  the therapies for any number of other reasons,  including
whether the mode of administration of our  products is effective for certain conditions, and whether the
physicians are already using competing products  that satisfy their  treatment objectives. Physicians,
patients, third-party payors and the medical  community may not accept and use any  product candidates
that we, or our collaborative partners,  develop. If our products do  not  achieve significant  market
acceptance and use, we will not be able  to  recover  the significant  investment we have  made in
developing such products and our business will be severely harmed.

We may be unable to compete successfully.

The markets in which we compete are well established and  intensely competitive. We may  be
unable to compete successfully against our current and future competitors. Our failure to compete
successfully may result in lower volume sold, pricing  reductions, reduced gross  margins and failure to
achieve market acceptance for our potential products. Our  competitors include research institutions,
pharmaceutical companies and biotechnology  companies, such as  Pfizer, Seattle  Genetics, Roche and
Bristol-Myers Squibb. Many of these  organizations have substantially more experience and more

36

capital, research and development, regulatory,  manufacturing, human and other resources than we  do.
As a result, they may:

(cid:127) develop products that are safer or  more effective  than  our product candidates;

(cid:127) obtain FDA and other regulatory approvals  or reach  the market with  their products more

rapidly than we can, reducing the potential sales of our product  candidates;

(cid:127) devote greater resources to market or sell their  products;

(cid:127) adapt more quickly to new technologies and scientific  advances;

(cid:127) initiate or withstand substantial price competition more  successfully than we can;

(cid:127) have greater success in recruiting skilled scientific workers from  the  limited pool of available

talent;

(cid:127) more effectively negotiate third-party licensing  and collaboration  arrangements;  and

(cid:127) take advantage of acquisitions or other opportunities  more readily than we  can.

A number of pharmaceutical and biotechnology companies are currently developing products
targeting the same types of cancer that we target, and some of our competitors’ products  have entered
clinical trials or already are commercially  available.

Our product candidates, if approved and  commercialized,  will also compete against

well-established, existing, therapeutic  products that are  currently reimbursed by government  healthcare
programs, private health insurers and  health maintenance organizations. In addition, if our product
candidates are approved and commercialized, we  may  face competition from biosimilars. The route to
market for biosimilars was established  with the  passage of the PPACA  in March  2010. The PPACA
establishes a pathway for the FDA approval of follow-on biologics and provides twelve  years  data
exclusivity for reference products and an additional six  months exclusivity period if pediatric studies are
conducted. In Europe, the European Medicines  Agency has issued guidelines  for approving products
through an abbreviated pathway, and  biosimilars  have been approved in Europe. If  a biosimilar  version
of one of our potential products were approved in the U.S. or Europe, it could have a negative effect
on sales and gross profits of the potential product and our financial  condition.

We  face and will continue to face intense competition from  other companies for collaborative
arrangements with pharmaceutical and  biotechnology companies, for  relationships with  academic and
research institutions and for licenses  to proprietary technology. In addition, we  anticipate that we will
face increased competition in the future  as  new companies enter our markets and as scientific
developments surrounding antibody-based  therapeutics for  cancer continue  to  accelerate. While we will
seek to expand our technological capabilities  to  remain  competitive,  research and  development by
others may render our technology or  product  candidates obsolete or noncompetitive or  result in
treatments or cures superior to any therapy  developed by us.

If we are unable to protect our intellectual property rights adequately, the value of  our technology  and
our product candidates could be diminished.

Our success depends in part on obtaining,  maintaining  and enforcing our patents and other

proprietary rights and our ability to avoid  infringing the proprietary rights of others. Patent law relating
to the scope of claims in the biotechnology field  in which we operate  is still  evolving,  is surrounded by
a great deal of uncertainty and involves  complex legal, scientific and factual questions. To date, no
consistent policy has emerged regarding the  breadth of claims allowed  in biotechnology  patents.
Accordingly, our pending patent applications may not result in  issued patents or in  patent  claims  as
broad as in the original applications.  Although we own numerous patents, the issuance of  a patent is

37

not conclusive as to its validity or enforceability. Through  litigation, a third party may  challenge the
validity or enforceability of a patent after its  issuance.

Patents and applications owned or licensed by us may become the subject of interference,
opposition, nullity, or other proceedings  in a  court or  patent office in the U.S. or in a  foreign
jurisdiction to determine validity, enforceability  or priority of invention,  which could result  in
substantial cost to us. An adverse decision  in such a  proceeding may result in our loss of rights  under a
patent or patent application. It is unclear  how much protection, if any, will  be  given to our patents if
we attempt to enforce them or if they  are  challenged  in court  or in  other  proceedings. A competitor
may successfully invalidate our patents  or a challenge  could result in  limitations of the  patents’
coverage. In addition, the cost of litigation or interference proceedings to uphold the validity of  patents
can be substantial. If we are unsuccessful  in these proceedings, third  parties may be able to use  our
patented technology without paying us  licensing  fees  or royalties.  Moreover, competitors may  infringe
our  patents or successfully avoid them through  design innovation.  To  prevent infringement  or
unauthorized use, we may need to file infringement claims,  which are expensive  and time-consuming. In
an infringement proceeding, a court  may  decide that a patent of ours is not valid. Even if the  validity
of our patents were upheld, a court may  refuse  to  stop the other party from using the  technology at
issue on the ground that its activities are not  covered by our patents.

The Leahy-Smith America Invents Act was signed into law on September 16,  2011, and became

fully effective in March 2013. In general, the legislation attempts to address  issues  surrounding the
enforceability of patents and the increase in patent litigation by, among other things, moving  to  a first
inventor-to-file system, establishing new procedures for  challenging  patents and  establishing different
methods for invalidating patents. Governmental rule-making implementing the new statute  is evolving
and will continue to introduce new substantive rules  and procedures, particularly with regard to
post-grant proceedings such as  inter partes review and post-grant review. In due course,  the courts  will
interpret various aspects of the law and related agency  rules in ways that we cannot predict, potentially
making it easier for competitors and  other  interested parties to challenge our patents, which, if
successful, could have a material adverse effect on our business and prospects. In addition, as the
United States Supreme Court has become increasingly active in reviewing U.S. patent law in recent
years, and the extent to which their recent decisions will affect our ability to enforce certain types of
claims under  our U.S. patents or obtain  future patents in certain areas  is difficult to predict at this
time.

Policing unauthorized use of our intellectual property is difficult, and we may not be able to
prevent misappropriation of our proprietary rights,  particularly in countries where the laws may not
protect such rights as fully as in the U.S.

In addition to our patent rights, we also rely  on unpatented technology, trade secrets, know-how

and confidential information. Third parties may independently develop substantially equivalent
information and techniques or otherwise gain access to or disclose  our technology. We may not be able
to effectively protect our rights in unpatented technology,  trade secrets, know-how and  confidential
information. We require each of our employees, consultants and corporate partners to execute a
confidentiality agreement at the commencement  of an employment, consulting or collaborative
relationship with us. Further, we require  that all employees enter into  assignment of  invention
agreements as a condition of employment. However, these agreements may not provide effective
protection of our information or, in the  event of unauthorized use or  disclosure, they  may not provide
adequate remedies.

38

Any inability to license proprietary technologies or processes from third parties  which  we  use in
connection with the development and manufacture of our product candidates may impair our business.

Other companies,  universities and research institutions have or may obtain patents  that  could  limit

our  ability to use, manufacture, market or sell our  product candidates  or  impair  our  competitive
position. As a result, we would have  to  obtain licenses from  other parties before we  could  continue
using, manufacturing, marketing or selling  our potential  products.  Any  necessary licenses may  not  be
available on commercially acceptable terms, if at  all.  If we  do not obtain required  licenses,  we may not
be able to market our potential products at all or we may encounter significant delays in product
development while we redesign products or  methods that are found to infringe on  the patents held by
others.

We may incur substantial costs as a  result  of litigation or other proceedings relating to  patent and
other intellectual property rights held  by  third parties and  we  may be unable  to protect our rights to,
or to commercialize, our product candidates.

Patent litigation is very common in the biotechnology and  pharmaceutical industries. Third parties

may assert patent or other intellectual  property infringement claims  against  us with respect  to  our
technologies, products or other matters.  From time to time,  we  have received  correspondence from
third parties alleging that we infringe  their intellectual property rights. Any claims that might be
brought against us alleging infringement of patents may cause us to incur significant expenses  and, if
successfully asserted against us, may cause us to pay  substantial damages and  limit our  ability to use the
intellectual property subject to these  claims.  Even if we were to prevail, any litigation would be costly
and time-consuming and could divert the  attention of our management and key personnel from our
business operations. Furthermore, as a  result of a  patent infringement suit, we may  be  forced to stop or
delay developing, manufacturing or selling potential products  that incorporate the challenged
intellectual property unless we enter into  royalty  or license agreements. There may  be  third-party
patents, patent applications and other intellectual  property  relevant  to  our potential  products that may
block or  compete with our products  or processes.  In  addition, we sometimes undertake research and
development with respect to potential  products even  when we are aware of third-party patents  that  may
be relevant to our potential products, on the basis that  such patents may be challenged or  licensed by
us. If our subsequent challenge to such  patents were not to prevail,  we may not be able to
commercialize our potential products  after having already incurred significant  expenditures unless we
are able to license the intellectual property  on commercially  reasonable terms.  We  may not be able  to
obtain royalty or license agreements on  terms acceptable to us, if at all. Even  if we were able  to  obtain
licenses to such technology, some licenses may be non-exclusive, thereby giving our competitors access
to the same technologies licensed to  us.  Ultimately, we may be unable to  commercialize some  of our
potential products or may have to cease  some of our business operations, which could severely harm
our  business.

We use hazardous materials in our business, and any claims relating  to  improper  handling, storage or
disposal of these materials could harm  our business.

Our research and development and manufacturing activities  involve the controlled use of
hazardous materials, chemicals, biological  materials and  radioactive compounds.  We are  subject to
federal, state and local laws and regulations governing the  use, manufacture,  storage,  handling and
disposal of these materials and certain waste products. Although  we  believe  that  our  safety procedures
for handling and disposing of these materials comply with the standards  prescribed  by  applicable laws
and regulations, we cannot completely  eliminate  the risk of accidental contamination or  injury  from
these materials. In the event of such an accident,  we could be held liable for any  resulting damages,
and any liability could exceed our resources. We  may  be  required to incur significant costs  to  comply

39

with these laws in the future. Failure  to  comply  with these laws could result  in fines and the revocation
of permits, which could prevent us from  conducting our business.

We face product liability risks and may  not be able to  obtain adequate insurance.

While we secure waivers from all participants in our clinical  trials, the use of our product
candidates during testing or after approval entails an  inherent risk of adverse effects, which could
expose us to product liability claims. Regardless of their merit  or  eventual outcome,  product liability
claims may result in:

(cid:127) decreased demand for our product;

(cid:127) injury to our reputation and significant negative media  attention;

(cid:127) withdrawal of clinical trial volunteers;

(cid:127) costs of litigation;

(cid:127) distraction of management; and

(cid:127) substantial monetary awards to plaintiffs.

We  may not have sufficient resources to satisfy any liability  resulting from these  claims. We
currently have product liability insurance  for products  which are  in clinical testing,  however, our
coverage may not  be adequate in scope  to protect us  in the event  of a successful  product liability claim.
Further, we may not be able to maintain our current insurance  or obtain general product liability
insurance on reasonable terms and at  an acceptable cost  if we or our collaborative partners begin
commercial production of our proposed product candidates. This insurance, even  if  we can obtain and
maintain it, may not be sufficient to provide us  with adequate coverage against potential liabilities.

We depend on our key personnel and we  must continue  to attract and  retain key employees and
consultants.

We  depend on our key scientific and management personnel. Our ability to pursue the

development of our current and future  product  candidates depends largely  on retaining the services of
our  existing personnel and hiring additional qualified scientific personnel to perform research and
development. We will also need to hire personnel with expertise  in clinical  testing, government
regulation, manufacturing, marketing  and finance.  Attracting and retaining qualified personnel will be
critical to our success. We may not be  able to attract and retain  personnel on acceptable  terms given
the competition for such personnel among  biotechnology, pharmaceutical and healthcare companies,
universities and non-profit research institutions. Failure  to retain our  existing key management and
scientific personnel or to attract additional  highly qualified personnel could delay the development of
our  product candidates and harm our  business.

Our stock price can fluctuate significantly and  results announced by us and  our collaborators  can
cause our stock price to decline.

Our stock price can fluctuate significantly due to business developments  announced by us and by

our  collaborators, or as a result of market trends and daily  trading  volume. The business developments
that could impact our stock price include disclosures  related to clinical findings with compounds that
make use of our ADC technology, new  collaborations and clinical advancement or  discontinuation  of
product  candidates that make use of  our ADC  technology. Our stock price  can also  fluctuate
significantly with the level of overall investment  interest  in small-cap biotechnology stocks.

Our operating results have fluctuated in the past and are likely to continue to do so in the  future.

Our revenue is unpredictable and may fluctuate due to the timing  of  non-recurring  licensing fees,

40

decisions of our collaborative partners  with  respect to our agreements with them,  reimbursement for
manufacturing services, the achievement  of  milestones and our receipt of  the  related milestone
payments under new and existing licensing and collaboration agreements. Revenue  historically
recognized under our prior collaboration  agreements may not be an  indicator of revenue  from any
future collaboration. In addition, our expenses are unpredictable  and may  fluctuate from quarter to
quarter due to the timing of expenses,  which  may include obligations  to  manufacture  or supply product
or payments owed by us under licensing or collaboration  agreements. It is  possible  that  our quarterly
and/or annual operating results will not  meet the expectations of securities  analysts  or investors, causing
the market price of our common stock to decline. We believe that quarter-to-quarter  and year-to-year
comparisons of our operating results  are not good  indicators of our future performance and  should not
be relied upon to predict the future performance  of our stock price.

The potential sale  of additional shares  of our common stock may cause our stock price  to decline.

Pursuant to shelf registration statements  filed  with the Securities and Exchange Commission, in

July 2012, we sold 6,250,000 shares of our  common  stock at $16.00  per  share in  a public offering
resulting in gross proceeds of $100 million; in fiscal 2011, we sold 7,800,000  shares of our common
stock at $12.00 per share in a public offering resulting in gross proceeds  of $93.6 million;  in fiscal 2010,
we sold 10,350,000 shares of our common  stock at  $8.00 per  share in a public offering  resulting in  gross
proceeds of $82.8 million; and in fiscal  2009, we sold 5,750,000 shares of our  common stock at  $7.00
per  share in a public offering resulting  in  gross proceeds of $40.3 million. The potential sale of
additional shares of our common stock  may  be  dilutive to our  shares outstanding and may cause our
stock price to decline.

We do not intend to pay cash dividends  on our common stock.

We  have not paid cash dividends since  our  inception and do not intend to  pay cash  dividends  in
the foreseeable future. Therefore, shareholders will have to rely on appreciation in  our stock  price, if
any, in order to achieve a gain on an investment.

41

A WARNING ABOUT FORWARD-LOOKING STATEMENTS

This report includes forward-looking statements  within the meaning  of the Private Securities
Litigation Reform Act of 1995. These  statements relate  to analyses  and other  information which are
based on  forecasts of future results and estimates of amounts that are not yet  determinable. These
statements also relate to our future prospects,  developments and business  strategies.

These forward-looking statements are identified by  their  use of terms  and  phrases,  such as
‘‘anticipate,’’ ‘‘believe,’’ ‘‘could,’’ ‘‘estimate,’’ ‘‘expect,’’  ‘‘intend,’’ ‘‘may,’’ ‘‘plan,’’ ‘‘predict,’’ ‘‘project,’’
‘‘will’’  and other similar terms and phrases,  including references to assumptions.  These statements are
contained in the ‘‘Business,’’ ‘‘Risk Factors’’ and ‘‘Management’s  Discussion  and Analysis of Financial
Condition and Results of Operations’’ sections,  as well as  other  sections  of this Annual Report on
Form 10-K.

These forward-looking statements involve known and unknown risks, uncertainties  and other

factors that may cause actual results to be materially different from those contemplated by our  forward-
looking statements. These known and unknown risks,  uncertainties and other factors are described in
detail  in the ‘‘Risk Factors’’ section and in other  sections  of this Annual Report on  Form 10-K.  We
disclaim any intention or obligation to update or revise any forward-looking  statements,  whether as a
result of new information, future events  or otherwise.

Item 1B. Unresolved Staff Comments

None.

Item 2. Properties

We  lease approximately 108,000 square feet of  laboratory and office  space in a building located at
830 Winter Street, Waltham, MA. The term of the 830  Winter Street lease expires on March 31, 2026,
with an option for us to extend the lease  for two additional five-year terms. In December 2009, we
entered into a sublease, as sublessor, to rent 14,100 square feet of our  original office and laboratory
space at 830 Winter Street, Waltham, MA  through  January 2015.  Due to space requirements, in April
2012, we entered into a sublease agreement for the rental  of 7,310 square feet of additional laboratory
and office space at 830 Winter Street, Waltham, MA for  a term of three years. We  also lease
approximately 43,850 square feet of space at 333  Providence Highway, Norwood, MA, which serves  as
our  conjugate manufacturing facility and office space. The 333 Providence  Highway lease  expires on
June 30, 2018, with an option for us  to  extend the lease for an additional five-year term. Due to space
requirements, in April 2013, we entered into a  lease agreement  for the rental of 7,507 square feet of
office space at 100 River Ridge Drive,  Norwood, MA. The initial term of the lease  is for five years and
two months commencing in July 2013 with an option  for us to extend the lease for an additional
five-year  term.

Item 3. Legal Proceedings

From time to time we may be a party to various  legal proceedings arising in the ordinary course of

our  business. We are not currently subject to any material legal proceedings.

Item 3.1. Executive Officers of the Registrant

ImmunoGen’s executive officers are  appointed by the Board of Directors at the first meeting of
the Board following the annual meeting  of shareholders or  at other Board meetings as appropriate, and
hold office until the first Board meeting following the next annual meeting of  shareholders and until a
successor is chosen, subject to prior death, resignation or removal. Information regarding our executive
officers is presented below.

42

Daniel M. Junius, age 62, joined ImmunoGen in  2005, and has served as  our  President  and Chief

Executive Officer since 2009. Mr. Junius has  also served as  a  director  of ImmunoGen since 2008 and  is
a director of IDEXX Laboratories, Inc.  Mr. Junius holds a Masters  of  Management from Northwestern
University’s Kellogg School of Management.

John M. Lambert, PhD, age 63, joined ImmunoGen  in 1987, and has  served as our Executive Vice

President and Chief Scientific Officer  since 2008. Dr.  Lambert holds a PhD in Biochemistry from
University of Cambridge in England, and completed his postdoctoral work at  the University of
California at Davis and at Glasgow University in  Scotland.

David B. Johnston, age 59, joined ImmunoGen in  2013, and  has served as our  Executive Vice
President and Chief Financial Officer  since that  date. Prior  to  joining ImmunoGen,  Mr.  Johnston
served as Chief Financial Officer of AVEO Pharmaceuticals, Inc.,  a biotechnology company, from 2007
to 2013. Mr. Johnston holds a Master of  Business Administration from the University  of Michigan.

Charles Q. Morris, MB, ChB, MRCP (UK), age 49, joined  ImmunoGen in  November 2012, and
has served as our Executive Vice President  and  Chief  Development  Officer since that date. Prior  to
joining ImmunoGen, he served as Executive  Vice President and Chief Medical Officer  of Allos
Therapeutics, Inc., a biotechnology company,  from 2010 until its acquisition in  2012. Prior to that he
served as Vice President, Worldwide Clinical  Research, at Cephalon, Inc., a biotechnology company,
from 2008 to 2010. Dr. Morris holds  his  medical  degrees  from Sheffield  University Medical School and
is a member of the Royal College of Physicians of London.

James J. O’Leary, MD, age 50, joined  ImmunoGen in 2008,  and has served as our Vice  President

and Chief Medical Officer since that date. Dr. O’Leary  has a  Doctor of Medicine degree from  the
State University of New York—Health Science Center at  Brooklyn.

Craig Barrows, age 59, joined ImmunoGen  in 2007, and has  served as our Vice President, General

Counsel and Secretary since that date.

Ellie Harrison, age 59, joined ImmunoGen  in February 2014,  and has served as our Vice President
and Chief Human Resources Officer  since that date. Prior to joining ImmunoGen, she served as Senior
Vice President of Human Resources of Blue Cross and Blue  Shield of  Rhode Island,  a healthcare
provider, from 2013 to February 2014.  Prior to that she served as a Managing Director and  Senior
Human Resources Advisor to the global consumer banking organization of Citigroup,  a financial
institution, from 2009 to 2012.

Peter J. Williams, age 60, joined ImmunoGen in  August 2009, and has served as our Vice

President, Business Development since that date.

Item 4. Mine Safety Disclosures

None.

43

PART II

Item 5. Market for Registrant’s Common Equity, Related Stockholder  Matters and Issuer  Purchases of

Equity Securities

Market Price of Our Common Stock  and Related Stockholder Matters

Our common stock is quoted on the  NASDAQ  Global  Select Market under the  symbol ‘‘IMGN.’’
The table below sets forth the high and low closing price per share of our common  stock as reported
by NASDAQ:

Fiscal Year 2014

High

Low

Fiscal Year 2013

High

Low

First  Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Second Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fourth Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$20.25
$18.19
$17.80
$15.59

$15.07
$12.55
$14.20
$10.69

$18.10
$15.77
$16.54
$18.83

$12.51
$10.85
$12.92
$13.91

As of August 20, 2014, the closing price per share of our common stock was $11.89,  as reported by

NASDAQ, and we had approximately 675  holders  of  record of our common stock.

We  have not paid any cash dividends on our  common stock since our  inception and  do  not  intend

to pay any cash dividends in the foreseeable future.

Recent  Sales of Unregistered Securities; Uses of Proceeds from  Registered Securities; Issuer
Repurchases of Equity Securities

None.

Item 6. Selected Financial Data

The following table (in thousands, except per share  data) sets  forth our  consolidated financial data
for each  of our five fiscal years through our fiscal  year  ended June  30, 2014. The  information set  forth
below should be read in conjunction  with ‘‘Management’s Discussion and Analysis of Financial
Condition and Results of Operations’’ and the  consolidated financial statements  and related notes
included elsewhere in this Annual Report  on  Form 10-K.

Year Ended June 30,

2014

2013

2012

2011

2010

Consolidated Statement of Operations  Data:
Total revenues . . . . . . . . . . . . . . . . . . . . . . . .
Total operating expenses . . . . . . . . . . . . . . . . .
Other income (expense), net . . . . . . . . . . . . . .
(Benefit) provision for income taxes . . . . . . . .

$ 59,896
131,427
167
—

$ 35,535
108,544
198
—

$ 16,357
89,614
(62)
—

$ 19,305
79,493
1,914
—

$ 13,943
65,178
58
(265)

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ (71,364) $ (72,811) $ (73,319) $ (58,274) $ (50,912)

Basic and diluted net loss per common  share . .

$

(0.83) $

(0.87) $

(0.95) $

(0.85) $

(0.87)

Basic and diluted weighted average common

shares outstanding . . . . . . . . . . . . . . . . . . .

85,481

84,063

76,814

68,919

58,845

Consolidated Balance Sheet Data:
Cash, cash equivalents and marketable

securities . . . . . . . . . . . . . . . . . . . . . . . . . .
Total assets . . . . . . . . . . . . . . . . . . . . . . . . . .
Shareholders’ equity . . . . . . . . . . . . . . . . . . . .

$142,261
165,318
75,699

$194,960
213,596
121,847

$160,938
180,308
83,890

$191,206
217,641
139,969

$110,298
137,208
102,048

44

Item 7. Management’s Discussion and Analysis  of Financial Condition and Results of Operations

Overview

Since our inception, we have been principally  engaged  in the development of  novel, antibody-drug

conjugates, or ADC’s, for the treatment  of cancer  using  our expertise in cancer  biology, monoclonal
antibodies, highly potent cytotoxic, or  cell-killing, agents,  and the design of linkers that enable  these
agents to remain stably attached to the  antibodies while in the blood  stream  and released in  their  fully
active  form after delivery to a cancer cell. An anticancer compound  made  using  our  ADC technology
consists of a monoclonal antibody that binds  specifically  to an antigen target found  on the surface of
cancer cells with one of our proprietary cell-killing agents attached to the antibody using one of our
engineered linkers. Its antibody component enables an  ADC  compound to bind specifically to cancer
cells that express its target antigen, the  highly potent cytotoxic agent serves to kill the cancer cell, and
the engineered linker controls the release  and activation  of the cytotoxic agent inside  the cancer cell.
With some ADC compounds, the antibody component also has anticancer activity of its own. Our ADC
technology is designed to enable the  creation of highly effective, well-tolerated anticancer  products. All
of the ADC compounds currently in  clinical testing  contain either  DM1 or DM4 as the  cytotoxic  agent.
Both DM1 and DM4, collectively DMx, are our proprietary derivatives of a  cytotoxic  agent  called
maytansine. We also use our expertise in antibodies and  cancer biology to develop ‘‘naked,’’ or
non-conjugated, antibody anticancer product  candidates.

We  have used our proprietary ADC technology  in conjunction with our  in-house antibody expertise

to develop our own anticancer product  candidates.  We  have also  entered into agreements that enable
companies to use our ADC technology to develop and commercialize product candidates  to  specified
targets. Under the terms of our agreements, we are generally entitled to upfront fees, milestone
payments, and royalties on any commercial product sales.  In  addition,  under certain agreements  we are
compensated for research and development activities performed at our  collaborative partner’s request
at negotiated prices which are generally consistent with what  other third  parties would charge. We are
compensated to manufacture preclinical  and clinical materials and  deliver cytotoxic agent material at
negotiated prices which are generally  consistent with what other  third parties would  charge. Currently,
our  partners include Amgen, Bayer HealthCare, Biotest, CytomX,  Lilly,  Novartis, Roche and Sanofi.
We  expect that substantially all of our  revenue for  the foreseeable future  will result from payments
under our collaborative arrangements.  Details for some of our major  and recent collaborative
agreements can be found in this Form 10-K under Item 1.  Business.

To date, we have not generated revenues  from commercial sales of internal products and  we expect

to incur significant operating losses for  the  foreseeable future. As of June 30, 2014,  we had
approximately $142.3 million in cash  and cash equivalents compared  to  $195 million as of June 30,
2013.

We  anticipate that future cash expenditures will  be  partially offset by collaboration-derived

proceeds, including milestone payments,  royalties  and upfront  fees.  Accordingly, period-to-period
operational results may fluctuate dramatically based  upon the  timing of receipt of  the proceeds.  We
believe that our established collaborative  agreements, while subject  to  specified milestone achievements,
will provide funding to assist us in meeting  obligations under  our collaborative agreements while also
assisting in providing funding for the  development of  internal  product candidates  and technologies.
However, we can give no assurances that  such collaborative agreement  funding  will,  in fact, be realized
in the time frames we expect, or at all.  Should we or our partners not meet some or all of the  terms
and conditions of our various collaboration  agreements, we  may  be  required  to  secure alternative
financing arrangements, find additional  partners  and/or defer or  limit some or  all  of  our  research,
development and/or clinical projects.  However, we cannot provide  assurance that any such opportunities
presented by additional partners or alternative  financing arrangements will  be  entirely available to us, if
at all.

45

Critical Accounting Policies

We  prepare our consolidated financial  statements  in accordance with accounting principles

generally accepted in the U.S. The preparation of  these financial statements  requires us to make
estimates and judgments that affect the reported amounts of assets, liabilities, revenues  and expenses
and related disclosure of contingent assets and liabilities. On  an on-going  basis, we evaluate our
estimates, including those related to our  collaborative agreements, clinical  trial  accruals, inventory and
stock-based compensation. We base our estimates  on historical experience and various other
assumptions that we believe to be reasonable  under the  circumstances.  Actual results may differ from
these estimates.

We  believe the following critical accounting policies reflect our more significant judgments  and

estimates used in the preparation of our consolidated  financial  statements.

Revenue Recognition

We  enter into licensing and development agreements with collaborative partners for  the

development of monoclonal antibody-based  anticancer therapeutics.  The  terms of these agreements
contain multiple deliverables which may include (i) licenses, or options to  obtain  licenses, to our ADC
technology, (ii) rights to future technological  improvements, (iii)  research activities  to  be  performed on
behalf of the collaborative partner, (iv)  delivery of cytotoxic agents and (v) the  manufacture of
preclinical or clinical materials for the collaborative  partner. Payments to us  under these agreements
may include upfront fees, option fees,  exercise fees, payments  for research activities, payments for the
manufacture of preclinical or clinical  materials, payments  based upon  the achievement of  certain
milestones and royalties on product sales.  We  follow  the provisions of  the Financial Accounting
Standards Board (FASB) Accounting  Standards  Codification  (ASC) Topic 605-25,  ‘‘Revenue
Recognition—Multiple-Element Arrangements,’’ and ASC Topic 605-28,  ‘‘Revenue Recognition—
Milestone Method,’’ in accounting for these agreements. In  order to account for  these agreements, we
must identify the deliverables included  within the agreement and evaluate which deliverables represent
separate units of accounting based on  if  certain criteria  are met, including  whether the delivered
element has stand-alone value to the  collaborator. The consideration  received  is allocated among the
separate units of accounting, and the  applicable revenue recognition criteria are applied to each of  the
separate units.

At June  30, 2014, we had the following two types of agreements with the  parties identified below:

(cid:127) Development and commercialization licenses  to  use our ADC technology and/or  certain  other

intellectual property to develop compounds to a specified target antigen (referred to as
development and commercialization licenses, as distinguished from  our right-to-test agreements
described elsewhere):

Amgen (four exclusive single-target licenses*)

Bayer HealthCare (one exclusive single-target  license)

Biotest (one exclusive single-target license)

Lilly (one exclusive single-target license)

Novartis (two exclusive single-target licenses  and one  license to two related targets: one  target
on an exclusive basis and the second target  on a  non-exclusive  basis)

Roche, through its Genentech unit (five exclusive single-target licenses)

Sanofi (one exclusive single-target license and one exclusive license to multiple individual
targets)

* Amgen has sublicensed one of its exclusive single-target licenses to Oxford BioTherapeutics Ltd.

46

(cid:127) Option/research agreement for a defined period of time  to  secure development and

commercialization licenses to use our  ADC technology to develop anticancer compounds to
specified targets on established terms (referred to herein as right-to-test agreements):

Sanofi

Novartis

Lilly

CytomX

There are no performance, cancellation,  termination  or refund provisions in any of the

arrangements that contain material financial  consequences  to  us.

Development and Commercialization Licenses

The deliverables under a development and commercialization  license agreement  generally  include

the exclusive license to our ADC technology with respect to a  specified antigen target, and may also
include deliverables related to rights  to  future technological improvements, research activities to be
performed on behalf of the collaborative  partner and the manufacture of preclinical or clinical
materials for the collaborative partner.

Generally, development and commercialization licenses contain non-refundable terms  for payments

and, depending on the terms of the agreement, provide  that we will  (i) at the collaborator’s request,
provide research services at negotiated  prices which  are generally consistent  with what  other  third
parties would charge, (ii) at the collaborator’s request, manufacture  and provide to it preclinical and
clinical materials or deliver cytotoxic  agents at  negotiated prices  which are generally consistent  with
what other third parties would charge, (iii)  earn payments upon the  achievement of certain milestones
and (iv) earn royalty payments, generally until  the later  of the last applicable  patent  expiration or  10 to
12 years after product launch. In the case of Kadcyla, however, the minimum royalty term  is 10  years
and the maximum royalty term is 12  years  on a  country-by-country basis,  regardless of  patent
protection. Royalty rates may vary over  the royalty  term depending on our intellectual property rights
and/or the presence of comparable competing products. We  may  provide  technical assistance  and share
any technology improvements with our  collaborators during the  term of the  collaboration  agreements.
We  do not directly control when or whether any collaborator will  request  research  or manufacturing
services, achieve milestones or become liable for royalty payments. As  a  result, we cannot predict  when
or if we will recognize revenues in connection  with any of the foregoing.

In determining the units of accounting, management evaluates  whether  the license has stand-alone

value from the undelivered elements  to  the collaborative  partner based on  the consideration of the
relevant facts and circumstances for each  arrangement.  Factors considered in this determination include
the research capabilities of the partner  and the  availability of ADC technology research expertise  in the
general marketplace. If we conclude that  the license  has stand-alone value and therefore will be
accounted for as a separate unit of accounting, we then determine the estimated selling prices  of the
license and all other units of accounting based on  market  conditions, similar arrangements entered into
by third parties, and entity-specific factors such as the  terms of our previous  collaborative  agreements,
recent preclinical and clinical testing  results of therapeutic products that use our ADC  technology, our
pricing practices and pricing objectives, the  likelihood that technological improvements will be made,
and, if made, will be used by our collaborators and  the nature  of the research services to be performed
on behalf of our collaborators and market  rates  for similar services.

Upfront payments on development and commercialization licenses are deferred if  facts and
circumstances dictate that the license does not have stand-alone value.  Prior to the adoption  of
Accounting Standards Update (ASU) No.  2009-13, ‘‘Revenue Arrangements with  Multiple

47

Deliverables’’ on July 1, 2010, we determined that our licenses  lacked  stand-alone value and were
combined with other elements of the  arrangement  and  any amounts  associated  with the license were
deferred and amortized over a certain  period, which we  refer to as our period of substantial
involvement. The determination of the  length of the period over which to defer revenue  is subject  to
judgment and estimation and can have an  impact on the  amount  of revenue  recognized in  a given
period. Historically our involvement with the development of a collaborator’s product  candidate has
been significant at  the early stages of  development, and lessens as it  progresses  into  clinical trials.  Also,
as a drug candidate gets closer to commencing pivotal testing  our collaborators  have sought  an
alternative site to manufacture their products, as our facility does not produce  pivotal or  commercial
drug product. Accordingly, we generally  estimate this  period of  substantial involvement to begin at the
inception of the collaboration agreement  and conclude  at the  end of non-pivotal Phase  II testing.  We
believe this period of substantial involvement is, depending on the nature of the license, on  average six
and one-half years. Quarterly, we reassess our periods of substantial involvement over which we
amortize our upfront license fees and make  adjustments  as appropriate. In the event  a collaborator
elects to discontinue development of a specific product candidate under a development  and
commercialization license, but retains  its  right  to  use our technology to develop an  alternative  product
candidate to the same target or a target substitute, we would  cease amortization of any remaining
portion of the upfront fee until there  is  substantial  preclinical activity  on another product candidate
and its remaining period of substantial involvement can be estimated. In the event  that  a development
and commercialization license were to be terminated, we  would recognize as revenue any portion  of  the
upfront fee that had not previously been  recorded as revenue,  but was classified  as deferred  revenue, at
the date of such termination.

Subsequent to the  adoption of ASU No.  2009-13, we  determined that  our research licenses  lack

stand-alone value and are considered for  aggregation with the  other  elements  of  the arrangement and
accounted for as one unit of accounting.

Upfront payments on development and commercialization licenses may be recognized  upon

delivery of the license if facts and circumstances dictate that  the  license  has stand-alone value from the
undelivered elements, which generally include rights to future  technological improvements, research
services, delivery of cytotoxic agents and the  manufacture of preclinical and  clinical materials.

We  recognize revenue related to research services that represent separate units of  accounting as

they are performed, as long as there is persuasive evidence of an arrangement, the fee is  fixed  or
determinable, and collection of the related  receivable is probable. We recognize revenue related  to  the
rights to future technological improvements  over the estimated term of the applicable license.

We  may also provide cytotoxic agents to our collaborators or produce preclinical  and clinical

materials for them at negotiated prices  which are generally consistent with  what other third parties
would charge. We recognize revenue on  cytotoxic  agents  and on preclinical  and clinical materials when
the materials have passed all quality testing  required for collaborator acceptance and title  and risk of
loss have transferred to the collaborator.  Arrangement consideration  allocated  to  the manufacture of
preclinical and clinical materials in a multiple-deliverable arrangement is  below our full  cost, and our
full cost is not expected to ever be below our contract selling  prices for  our existing collaborations.
During  the fiscal years ended June 30, 2014, 2013 and 2012, the difference between our full  cost to
manufacture preclinical and clinical materials on behalf of  our collaborators as compared to total
amounts received from collaborators  for the manufacture  of  preclinical and clinical  materials was
$2.3 million, $755,000, and $85,000, respectively. The majority of our costs to produce these preclinical
and clinical materials are fixed and then allocated  to  each batch based on the  number of batches
produced during the period. Therefore,  our costs  to  produce  these materials are significantly impacted
by the number of batches produced during the period.  The volume  of preclinical and clinical  materials
we produce is directly related to the number of clinical trials  we and our collaborators are preparing
for or currently have underway, the speed  of  enrollment  in those trials, the dosage  schedule  of  each

48

clinical trial and the time period such trials last.  Accordingly, the volume of preclinical and clinical
materials produced, and therefore our  per-batch  costs to manufacture these  preclinical and  clinical
materials, may vary significantly from period to period.

We  may also produce research material  for  potential  collaborators under material transfer
agreements. Additionally, we perform  research activities, including developing antibody specific
conjugation processes, on behalf of our collaborators  and potential  collaborators during the  early
evaluation and preclinical testing stages  of drug  development. We  record  amounts received for  research
materials produced or services performed  as a component of research and development  support
revenue. We also develop conjugation  processes for  materials  for later stage  testing and
commercialization for certain collaborators. We  are compensated at  negotiated rates and may receive
milestone payments for developing these  processes which are recorded as  a component of research and
development support revenue.

Our development and commercialization license  agreements  have milestone  payments which for

reporting purposes are aggregated into  three categories: (i)  development  milestones, (ii) regulatory
milestones, and (iii) sales milestones.  Development milestones are typically payable when  a product
candidate initiates or advances into different clinical trial phases. Regulatory  milestones are  typically
payable upon submission for marketing approval with the FDA or other countries’ regulatory
authorities or on receipt of actual marketing approvals for the  compound or for additional indications.
Sales milestones are typically payable when annual sales  reach  certain levels.

At the inception of each agreement that includes  milestone payments, we evaluate whether each

milestone is substantive and at risk to both parties on the basis  of the contingent  nature of the
milestone. This evaluation includes an assessment of  whether (a) the  consideration is commensurate
with either (1) the entity’s performance  to  achieve the milestone,  or (2) the enhancement of the value
of the delivered item(s) as a result of  a specific  outcome  resulting from the entity’s performance  to
achieve the milestone, (b) the consideration relates solely  to past performance  and (c) the
consideration is reasonable relative to all  of  the deliverables  and payment  terms within  the
arrangement. We evaluate factors such as  the scientific, regulatory,  commercial and other risks that
must be overcome to achieve the respective milestone, the level of effort and investment required to
achieve the respective milestone and  whether the milestone  consideration is reasonable  relative to all
deliverables and payment terms in the  arrangement in making this assessment.

Non-refundable development and regulatory milestones  that are expected to be achieved as a

result of our efforts during the period  of substantial  involvement are considered  substantive  and are
recognized as revenue upon the achievement of the  milestone, assuming  all  other  revenue recognition
criteria are met. Milestones that are not considered substantive because we do not contribute effort to
the achievement of such milestones are generally  achieved after the period  of substantial  involvement
and are recognized as revenue upon  achievement of the  milestone, as there  are no  undelivered
elements remaining and no continuing performance  obligations,  assuming all other  revenue recognition
criteria are met.

Under our development and commercialization license  agreements, we receive royalty  payments

based upon our licensees’ net sales of covered products.  Generally, under  these  agreements we  are to
receive royalty reports and payments  from  our  licensees approximately one quarter in arrears, that is,
generally in the second month of the quarter  after the licensee has sold the royalty  bearing product or
products. We recognize royalty revenues when we  can reliably estimate such amounts and collectability
is reasonably assured. As such, we generally recognize royalty  revenues  in the quarter reported to us by
our  licensees, or one quarter following the  quarter in which sales by  our licensees occurred.

49

Right-to-Test Agreements

Our right-to-test agreements provide collaborators the right to (a) test our ADC technology for  a

defined period of time through a research, or right-to-test, license,  (b) take  options, for a defined
period of time, to specified targets and  (c) upon  exercise  of  those options, secure or  ‘‘take’’ licenses to
develop and commercialize products  for the specified  targets on  established terms.  Under these
agreements, fees may be due to us (i)  at  the inception of the arrangement (referred to as ‘‘upfront’’
fees or payments), (ii) upon taking an  option with respect to a  specific target (referred to as option
fees or payments earned, if any, when the  option is ‘‘taken’’), (iii) upon the exercise of a  previously
taken option to acquire a development and commercialization  license(s)  (referred to as exercise  fees or
payments earned, if any, when the development  and  commercialization license  is ‘‘taken’’),  or (iv) some
combination of all of these fees.

The accounting for right-to-test agreements is  dependent on the nature  of the option granted to

the collaborative partner. Options are considered  substantive if,  at the  inception of a right-to-test
agreement, we are at risk as to whether  the  collaborative  partner will  choose  to  exercise  the options to
secure development and commercialization licenses. Factors that are considered in evaluating whether
options are substantive include the overall  objective  of  the arrangement,  the benefit the collaborator
might obtain from the agreement without  exercising the  options,  the  cost  to exercise the options
relative to the total upfront consideration,  and the  additional  financial commitments or  economic
penalties imposed on the collaborator  as  a result of  exercising the options.

For right-to-test agreements where the options to secure development and commercialization
licenses to our ADC technology are considered substantive,  we do not consider the development  and
commercialization licenses to be a deliverable at the  inception of the agreement. For those right-to-test
agreements entered into prior to the  adoption of  ASU No. 2009-13 where the options to secure a
development and commercialization license are considered substantive, we have deferred  the upfront
payments received and recognize this revenue over the  period during which the collaborator could elect
to take options for development and commercialization licenses.  These periods are specific to each
collaboration agreement. If a collaborator takes  an option to acquire a  development and
commercialization license under these agreements,  any  substantive option fee is  deferred and
recognized over the life of the option,  generally 12 to 18 months. If  a  collaborator  exercises an option
and takes a development and commercialization license to a specific  target, we  attribute the exercise
fee to the development and commercialization license. Upon exercise of  an  option to acquire a
development and commercialization license, we  would also attribute any remaining  deferred option fee
to the development and commercialization license and apply  the  multiple-element revenue recognition
criteria to the development and commercialization license and  any other deliverables to determine the
appropriate revenue recognition, which will be consistent with our  accounting policy for upfront
payments on single-target licenses. In  the event  a right-to-test  agreement were to be terminated,  we
would recognize as revenue any portion  of  the upfront fee  that had not previously been  recorded as
revenue, but was classified as deferred  revenue, at  the date  of  such termination. None of  our
right-to-test agreements entered into subsequent  to  the adoption of ASU No. 2009-13 has been
determined to contain substantive options.

For right-to-test agreements where the options to secure development and commercialization
licenses to our ADC technology are not  considered substantive,  we consider  the development and
commercialization license to be a deliverable  at the inception of the agreement  and apply the multiple-
element revenue recognition criteria to  determine  the appropriate  revenue  recognition. None  of our
right-to-test agreements entered into prior to the adoption of  ASU  No. 2009-13 has been  determined to
contain non-substantive options.

50

We  do not directly control when or if  any collaborator will exercise its options for development
and commercialization licenses. As a  result, we  cannot predict when or if we will  recognize revenues  in
connection with any of the foregoing.

Inventory

We  review our estimates of the net realizable value of our inventory  at each reporting  period. Our
estimate of the net realizable value of our  inventory  is subject  to  judgment and estimation. The actual
net realizable value of our inventory  could vary significantly  from  our estimates. We consider quantities
of raw materials in excess of twelve-month projected usage  that are not supported  by  firm,  fixed
collaborator orders and projections at the  time of  the assessment to be excess. During fiscal years 2014,
2013 and 2012, we obtained additional quantities of DMx  from our supplier which amounted to more
material than would be required by our collaborators over  the next twelve months and as a result, we
recorded  $364,000, $798,000 and $748,000,  respectively, of  charges to research and development
expense related to raw material inventory identified as excess. We also  recorded $38,000 to write down
certain raw material inventory to its net  realizable value,  which is also included in research and
development expense for the year ended June 30, 2012.  Our collaborators’ estimates of their clinical
material requirements are based upon expectations of their  clinical trials,  including the  timing, size,
dosing schedule and the maximum tolerated dose likely to be reached for the  compound being
evaluated. Our collaborators’ actual requirements  for clinical materials may  vary  significantly  from their
projections. Significant differences between our collaborators’ actual manufacturing orders and their
projections could result in our actual  twelve-month usage  of raw  materials varying  significantly  from
our  estimated usage at an earlier reporting period. Such differences and/or  reductions in  collaborators’
projections could indicate that we have  excess raw material inventory and we would then evaluate the
need to record write-downs, which would be included as charges to research and  development expense.

Stock-based Compensation

As of June 30, 2014, we are authorized to grant future awards under one share-based

compensation plan, which is the ImmunoGen, Inc. 2006  Employee,  Director and Consultant Equity
Incentive Plan. The stock-based awards are accounted  for under ASC Topic 718, ‘‘Compensation—
Stock Compensation,’’ pursuant to which  the estimated grant date fair value of awards is  charged to the
statement of operations over the requisite  service  period, which is the  vesting period. Such amounts
have been reduced by our estimate of forfeitures for unvested awards.

The fair value of each stock option is estimated on  the date  of grant using the  Black-Scholes
option-pricing model. Expected volatility  is based exclusively on  historical volatility data of  our stock.
The expected term of stock options granted  is based exclusively  on historical data and represents the
period of time that stock options granted are expected to be outstanding.  The  expected term is
calculated for and applied to one group of stock  options  as  we  do not  expect substantially  different
exercise or post-vesting termination behavior amongst our employee population.  The  risk-free rate of
the stock options is based on the U.S. Treasury rate in  effect at the time of  grant for  the expected  term
of the stock options. Estimated forfeitures are  based on  historical data  as well as  current trends.  Stock
compensation cost incurred during the years ended  June 30, 2014, 2013  and 2012  was $15.6 million,
$12.4 million and $9.9 million, respectively.

Future stock-based compensation may  significantly  differ based on changes in  the fair value of our

common stock and our estimates of expected volatility and the other relevant assumptions.

51

Results of Operations

Revenues

Our total revenues for the year ended  June  30, 2014 were $59.9  million compared with

$35.5 million and $16.4 million for the  years ended June 30,  2013 and 2012, respectively. The
$24.4 million increase in revenues in fiscal year 2014  from fiscal year 2013 is attributable to an increase
in license and milestone fees, royalty revenue and clinical materials revenue, partially  offset by a
decrease in research and development  support revenue,  all of which are discussed below. The
$19.1 million increase in revenues in fiscal year 2013  from fiscal year 2012 is attributable to all revenue
categories.

Revenue from license and milestone  fees  for  the year  ended June 30, 2014  increased  approximately
$15.3 million to $39.5 million from $24.2 million  in the year ended  June 30, 2013. Revenue  from license
and milestone fees for the year ended  June 30,  2012 was $9.2 million. Included  in license  and milestone
fees for the year ended June 30, 2014  is $7.8  million of  license revenue earned upon the execution  of  a
development and commercialization license by Lilly, two $5 million regulatory milestones  achieved
under our collaboration agreement with Roche, $18.2  million of license  revenue earned upon the
execution of two development and commercialization licenses and  a one-year  extension of the original
term of the multi-target agreement by  Novartis, and $2.2  million of revenue from  Amgen related  to  a
modification of an existing arrangement.  Included in  license  and milestone  fees  for the  year ended
June 30, 2013 was a $10.5 million regulatory  milestone achieved under our collaboration agreement
with Roche, a $500,000 development  milestone achieved under our collaboration agreement with  Sanofi
and $11.1 million of license revenue earned  upon the  execution of a development  and
commercialization license by Novartis.  Included in  license and milestone fees for the year ended
June 30, 2012 was a $3 million milestone payment related to the initiation of Phase II clinical testing of
SAR3419 achieved under our collaboration  agreement with  Sanofi and  two  $1 million milestone
payments related to regulatory milestones achieved under our  license agreements  with Amgen.  Also
during the year ended June 30, 2012, Biogen Idec terminated its exclusive  license to our ADC
technology to develop and commercialize therapeutic  compounds to the target Cripto and  as a result,
we recognized the remaining $270,000  of the $1  million upfront fee received  from Biogen Idec upon
execution of the license which had been previously  deferred. Also, during fiscal 2012, we made a
change in the estimate of our period  of  substantial involvement  as it  relates to our exclusive license
with Bayer HealthCare which resulted in an  increase to license  and milestone fees of $1.2  million for
the fiscal year ending June 30, 2012 compared  to  amounts that would have  been recognized pursuant to
our  previous estimate. The amount of license and milestone fees we earn is directly related  to  the
number of our collaborators, the collaborators’ advancement of the product candidates, and  the overall
success in the clinical trials of the product candidates. As such, the  amount  of license  and milestone
fees may vary widely from quarter to  quarter and year  to  year. Total revenue recognized from license

52

and milestone fees from each of our  collaborative  partners in the years ended June  30, 2014, 2013 and
2012 is included in the following table (in  thousands):

License and Milestone Fees

Collaborative Partner:

Year Ended June 30,

2014

2013

2012

Amgen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bayer HealthCare . . . . . . . . . . . . . . . . . . . . . . . . . .
Biogen Idec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Biotest
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lilly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Novartis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Roche . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sanofi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 2,351
—
—
25
7,830
18,353
10,000
896
—

$

883
521
—
25
—
11,131
10,500
1,167
—

$3,118
1,839
270
120
—
—
—
3,795
19

Total

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$39,455

$24,227

$9,161

Deferred revenue of $61.3 million at June 30, 2014  represents payments  received from  our
collaborators pursuant to our license agreements which we have  yet to earn  pursuant to our  revenue
recognition policy. Included within this amount is $13.1  million  of non-cash  consideration recorded in
connection with our arrangement with CytomX.

In February 2013, the US FDA granted marketing approval  to  Kadcyla, a product resulting  from
one of our development and commercialization  licenses with Roche,  through its Genentech unit. We
receive royalty reports and payments  related to sales  of Kadcyla from Roche one quarter in  arrears. In
accordance with our revenue recognition  policy, $10.3 million of royalties on net  sales  of  Kadcyla for
the twelve-month period ended March  31, 2014 were  recorded and included  in royalty revenue for  the
year ended June 30, 2014. We recorded $592,000 of royalties on net sales of Kadcyla for  the three-
month period ended March 31, 2013 in  our fourth  quarter  of  fiscal 2013. No royalty  revenue was
recorded  in fiscal year 2012. We expect  royalty revenue to increase in  future periods as  the underlying
net sales of Kadcyla increase.

Research and development support revenue was $7.2 million for the year ended  June 30, 2014,
$7.9 million for the year ended June 30,  2013, and $4.5 million for  the year  ended June 30, 2012.  These
amounts primarily represent research funding earned based on actual resources utilized under  our
agreements with our collaborators as shown in the table below. Also  included  in research and
development support revenue are fees for  developing antibody- specific conjugation  processes on behalf
of our collaborators and potential collaborators  during the early evaluation and preclinical  testing
stages of drug development. The amount of research and development support  revenue we earn is
directly related to the number of our collaborators  and  potential collaborators,  the stage of
development of our collaborators’ product candidates and the resources our collaborators allocate to
the development effort. As such, the amount of development fees may vary  widely from quarter to
quarter and year to year. Total revenue recognized  from research and development support  from each

53

of our collaborative partners in the years  ended June  30, 2014, 2013 and  2012 is included in  the
following table (in thousands):

Research and Development Support

Collaborative Partner:

Year Ended June 30,

2014

2013

2012

Amgen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Biotest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lilly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Novartis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 404
783
2,906
3,012
82

$ 417
921
806
5,605
124

$1,011
627
250
2,588
41

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$7,187

$7,873

$4,517

Clinical materials revenue increased  by approximately $65,000  to  $2.9 million  in the year ended

June 30, 2014 compared to $2.8 million in the  year  ended June  30, 2013. We earned  clinical materials
revenue of $2.7 million during the year ended June 30,  2012. During the years ended  June  30, 2014,
2013 and 2012, we shipped clinical materials in  support of a number of our collaborators’ clinical trials,
as well as preclinical materials in support  of certain collaborators’ development efforts and DMx
shipments to certain collaborators in  support of development and manufacturing efforts. We  are
compensated at negotiated prices which are generally consistent with  what other third-parties would
charge. The amount of clinical materials revenue  we earn, and the related  cost of clinical materials
charged to research and development  expense, is directly related to the number of clinical  trials our
collaborators who  use us to manufacture  clinical materials are preparing or have underway, the speed
of enrollment in those trials, the dosage  schedule  of each clinical trial and the time period, if  any,
during which patients in the trial receive clinical  benefit from  the clinical  materials,  and the  demand
our  collaborators have for clinical-grade material for process  development and  analytical  purposes. As
such, the amount of clinical materials  revenue and the related cost  of clinical  materials  charged to
research and development expense may  vary  significantly  from quarter to quarter and  year  to  year.

Research and Development Expenses

Our research and development expenses relate to (i) research to evaluate new targets  and to
develop and evaluate new antibodies, linkers and cytotoxic  agents,  (ii) preclinical testing  of our  own
and, in certain instances, our collaborators’  product candidates, and the cost of  our own clinical  trials,
(iii) development related to clinical and commercial manufacturing processes  and (iv)  manufacturing
operations which also includes raw materials. Our  research and development efforts have been
primarily focused in the following areas:

(cid:127) evaluation of potential antigen targets;

(cid:127) evaluation of internally developed and/or  in-licensed  product candidates  and technologies;

(cid:127) development and evaluation of additional cytotoxic agents and  linkers;

(cid:127) activities related to the process, preclinical  and clinical development of  our internal product

candidates;

(cid:127) process improvements to our ADC technology;

(cid:127) process improvements related to the production of DM1,  DM4 and  strain  development of their

precursor, ansamitocin P3;

(cid:127) operation and maintenance of our conjugate manufacturing facility, including production of our

own and our collaborators’ clinical materials;

54

(cid:127) production costs for the supply of antibody for  our internal product candidates,  including fill/

finish  services;

(cid:127) production costs for the supply of DMx  for  our  and our partners’ preclinical  and clinical

activities;

(cid:127) non-pivotal and pivotal development activities with contract manufacturers for the antibody
component of our internal product candidates,  linkers, and DM1,  DM4 and their precursor,
ansamitocin P3; and

(cid:127) activities pursuant to our development  and license agreements with various  collaborators.

Research and development expense for the  year  ended June  30, 2014 increased $19.9  million  to
$107.0 million from $87.1 million for the  year  ended June  30, 2013. Research and development  expense
was $69.2 million for the year ended June 30,  2012. During the year ended  June 30, 2014, we recorded
a $12.8 million non-cash charge to research and  development expense for technology rights obtained
under the collaboration agreement executed with  CytomX in January  2014. Research  and development
salaries and related expenses increased by $8.3 million to $47.6 million in  the year ended June 30, 2014
compared to the year ended June 30, 2013 and increased by $6.2  million in  the year  ended June 30,
2013 compared to the year ended June 30, 2012.  The  average number of  our research personnel
increased to 250 for the year ended June 30,  2014 compared to 226  for the year ended June 30,  2013.
We  had an average of 207 for the year  ended  June 30, 2012. Included in  salaries and related expenses
for the year ended June 30, 2014 is $10.3  million of stock  compensation costs compared to $7.3 million
and $5.3 million of stock compensation  costs  for  fiscal  years 2013 and  2012, respectively. The higher
stock compensation costs in fiscal years 2014  and 2013 are driven  by higher stock prices and  increases
in the number of annual options granted  due to increases  in personnel.

We  are unable to accurately estimate which  potential  product candidates, if  any, will eventually
move into our internal preclinical research program. We  are unable to reliably estimate the costs to
develop these products as a result of  the uncertainties related to discovery research efforts as  well as
preclinical and clinical testing. Our decision to move a  product candidate into the  clinical development
phase is  predicated upon the results  of  preclinical  tests.  We cannot  accurately predict which, if  any, of
the discovery stage product candidates will  advance from preclinical testing and move into our internal
clinical development program. The clinical  trial  and  regulatory approval processes for our product
candidates that have advanced or that  we  intend to advance to clinical  testing  are lengthy,  expensive
and uncertain in both timing and outcome. As  a result,  the pace and timing of  the clinical  development
of our product candidates is highly uncertain and  may not ever  result in approved products.
Completion dates and development costs will vary significantly  for each product  candidate and  are
difficult to predict. A variety of factors,  many  of  which are outside our  control,  could  cause or
contribute to the prevention or delay of  the successful completion of  our clinical trials, or  delay or
prevent our obtaining necessary regulatory approvals. The  costs to take a product through clinical trials
are dependent upon, among other factors, the  clinical indications, the  timing, size and design  of each
clinical trial, the number of patients enrolled in each trial, and the speed at which patients are enrolled
and treated. Product candidates may  be  found to be ineffective or to cause unacceptable side effects
during clinical trials, may take longer  to  progress through clinical  trials than anticipated,  may fail to
receive necessary regulatory approvals  or  may  prove  impractical  to  manufacture  in commercial
quantities at reasonable cost or with  acceptable quality.

The lengthy process of securing FDA  approvals for  new drugs requires the expenditure  of

substantial resources. Any failure by us  to  obtain, or any delay  in obtaining, regulatory approvals, would
materially adversely affect our product development  efforts and  our business overall.  Accordingly, we
cannot currently estimate, with any degree of certainty, the amount of time or  money  that  we will be
required to expend in the future on our product  candidates prior  to  their regulatory approval, if such
approval is ever granted. As a result of  these uncertainties  surrounding  the timing and outcome of our

55

clinical trials, we are currently unable to estimate  when, if  ever, our product  candidates that have
advanced into clinical testing will generate  revenues and cash flows.

We  do not track our research and development  costs by project. Since we use our research and
development resources across multiple research and development  projects,  we manage our research and
development expenses within each of the categories listed in the following table and described in more
detail below (in thousands):

Research and Development Expense

Year Ended June 30,

2014

2013

2012

Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preclinical and Clinical Testing . . . . . . . . . . . . . . . . .
Process and Product Development
. . . . . . . . . . . . . .
Manufacturing Operations . . . . . . . . . . . . . . . . . . . .

$ 30,793
34,562
8,296
33,307

$17,506
27,839
7,777
33,951

$16,827
21,143
7,203
24,019

Total Research and Development Expense . . . . . . . . .

$106,958

$87,073

$69,192

Research—Research includes expenses associated with  activities to evaluate new targets and  to

develop and evaluate new antibodies, linkers and cytotoxic  agents  for our  products and in  support of
our  collaborators. Such expenses primarily include personnel, fees to in-license certain technology,
facilities and lab supplies. Research expenses increased $13.3 million to $30.8  million  in fiscal year 2014
from fiscal year 2013 and $679,000 to  $17.5 million in fiscal  year 2013  from fiscal year 2012. This
increase in fiscal year 2014 was principally due  to  a $12.8 million non-cash charge  recorded for
technology rights obtained under the collaboration agreement executed with  CytomX in  January 2014
and to a lesser extent, an increase in salaries  and  related expenses. The increase in  fiscal 2013 was
principally due to an increase in salaries and related expenses.

Preclinical and Clinical Testing—Preclinical and clinical testing includes expenses  related to

preclinical testing of our own and, in  certain instances,  our collaborators’ product candidates,  regulatory
activities, and the cost of our own clinical  trials.  Such expenses include personnel, patient enrollment at
our  clinical testing sites, consultant fees, contract  services,  and facility expenses. Preclinical  and clinical
testing expenses increased $6.8 million  to  $34.6 million in  fiscal  year 2014 from fiscal  year 2013 and
$6.7 million to $27.8 million in fiscal  year 2013 from fiscal year 2012. The increase in  fiscal year  2014
was principally the result of higher salaries and related  expenses driven by an increase  in personnel  and
higher  stock compensation costs. The  increase  in fiscal year 2013  was  primarily  the result of  an increase
in clinical trial costs due primarily to  site expansion  and higher patient enrollment for  the
IMGN901 007 Phase II study for small-cell lung cancer and increased costs  incurred for the IMGN853
Phase I trial for ovarian cancer which was initiated during the second half of fiscal 2012 and  began
enrolling patients in fiscal 2013, as well as  an increase in  salaries and  related  expenses.

Process and Product Development—Process and product development expenses include costs  for

development of clinical and commercial manufacturing processes for our own and collaborator
compounds. Such expenses include the costs of personnel, contract services and facility expenses.  Total
development expenses increased $519,000 to $8.3 million in fiscal year  2014 from fiscal year 2013  and
expenses increased $574,000 to $7.8 million in fiscal year 2013  from fiscal year 2012. The  increase in
fiscal years 2014 and 2013 was primarily the  result of an  increase in salaries and  related expenses, as
well as an increase in contract service expense in fiscal  2014  driven primarily by development  activities
for IMGN779.

Manufacturing Operations—Manufacturing operations expense  includes costs to manufacture
preclinical and clinical materials for our  own and  our  collaborators’ product candidates, quality control
and quality assurance activities and costs to support  the operation  and maintenance of our conjugate
manufacturing facility. Such expenses include personnel, raw materials for  our  and our collaborators’

56

preclinical studies and clinical trials, non-pivotal and pivotal  development costs  with contract
manufacturing organizations, manufacturing supplies, and facilities expense. Manufacturing operations
expense decreased $644,000 to $33.3  million  in fiscal year 2014 from fiscal year 2013 and increased
$10 million to $34 million in fiscal year  2013 from fiscal  year 2012.  The decrease in fiscal year 2014 was
primarily the result of (i) a decrease in antibody development  and  supply  expense driven primarily  by
supply required in prior year for our  IMGN289 and IMGN901 programs, as well as pivotal activities
performed for our IMGN901 program during the  prior year, partially  offset  by  non-pivotal activities
performed and supply required for our IMGN779 program during the current year; (ii) a decrease in
fill/finish costs due primarily to costs to transfer our internal programs to  a new  supplier  during the
prior year period; and (iii) an increase in costs capitalized into inventory due to a  greater  number of
manufactured batches of conjugated  materials on behalf of our  collaborators.  Partially offsetting these
decreases, salaries and related expenses increased during the  current period and contract service
expense increased due primarily to increased study activities  related  to  our cytotoxic agents. The
increase in fiscal year 2013 was primarily  the result of (i)  an increase in antibody development and
supply expense driven by our IMGN901,  IMGN853, IMGN529 and IMGN289 programs; (ii) a decrease
in costs capitalized into inventory due  to  a lower  number of manufactured batches of conjugated
materials on behalf of our collaborators; and (iii) an increase in salaries and related expenses.

Antibody development and supply expense in anticipation of  potential future clinical trials, as  well

as our ongoing trials, was $7.2 million  in fiscal year 2014, $10.8 million  in fiscal year 2013, and
$4.9 million in fiscal year 2012. The process  of antibody production is lengthy due in part to the lead
time to establish a satisfactory production process at  a vendor. Accordingly,  costs incurred related  to
antibody  production and development  have fluctuated from period to period  and we expect these  cost
fluctuations to continue in the future.

We  expect that future research and development  expenses will increase due  to  our  continuing
advancement of our internal product  candidates through clinical trials,  as well as  expected increases in
salaries and related expenses.

General and Administrative Expenses

General and administrative expenses  for the  year ended June 30, 2014  increased $3.0 million  to
$24.5 million from $21.5 million for the  year ended June 30, 2013.  General and administrative expenses
for the year ended June 30, 2012 were  $20.4 million.  The increase in  fiscal year  2014 was primarily due
to an increase in salaries and related  expenses, particularly stock compensation costs,  as well as  an
increase in professional service fees, particularly consulting fees and patent expenses. The increase in
fiscal year 2013 was primarily due to  an increase in salaries and related expenses, particularly stock
compensation costs. We expect general and administrative  expenses to increase  in fiscal 2015 compared
to fiscal 2014 due primarily to increases  in salaries and related expenses and patent expenses.

Investment Income, net

Investment income for the years ended June 30, 2014,  2013 and 2012 was $44,000,  $126,000 and

$66,000, respectively.

Other Income (Expense), net

Other income (expense), net for the  years ended June 30,  2014, 2013 and 2012  was  $123,000,

$72,000 and $(128,000), respectively. During the years ended  June  30, 2014, 2013  and 2012, we
recorded  net gains (losses) on foreign  currency forward contracts  of $2,000, $197,000 and  $(173,000),
respectively. We incurred $120,000, $(153,000), and $17,000  in foreign currency exchange gains and
(losses) related to obligations with non-U.S. dollar-based suppliers and Euro  cash balances  maintained
to fulfill them during the years ended June  30, 2014, 2013 and 2012, respectively.

57

Liquidity and Capital Resources

Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Working capital
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shareholders’ equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$142,261
129,502
75,699

$194,960
181,511
121,847

As of June 30,

2014

2013

(In thousands)

Cash used for operating activities . . . . . . . . . . . . . . . . . . . . .
Cash used for investing activities . . . . . . . . . . . . . . . . . . . . .
Cash provided by financing activities . . . . . . . . . . . . . . . . . .

Cash Flows

Year Ended June 30,

2014

2013

2012

(In thousands)
$(53,650) $(60,299) $(34,288)
(2,968)
(3,696)
6,988
98,017

(8,185)
9,136

We  require cash to fund our operating  expenses, including the advancement  of our  own clinical

programs, and to make capital expenditures. Historically,  we  have funded our  cash requirements
primarily through equity financings in public  markets and payments from  our collaborators, including
license fees, milestones, research funding  and more recently, royalties. As of June 30,  2014, we  had
approximately $142.3 million in cash  and cash equivalents. Net cash used for operating  activities was
$53.7 million, $60.3 million and $34.3  million during the years ended  June  30, 2014, 2013  and 2012,
respectively. The principal use of cash  in  operating activities for all  periods  presented  was  to  fund  our
net loss, adjusted for non-cash items. Cash  used  for  operating activities in fiscal 2012  benefited from
the $20 million upfront payment received from Lilly  in January 2012 with  the execution of a right-
to-test  agreement between the companies.

Net cash used for investing activities  was $8.2  million,  $3.7 million and $3.0 million for  the years

ended June 30, 2014, 2013 and 2012,  respectively,  and  substantially  represents cash  outflows  from
capital expenditures. Capital expenditures  were $8.2  million,  $3.8 million and  $2.9 million for  the fiscal
years ended June 30, 2014, 2013 and  2012, respectively. Capital expenditures for  the years ended
June 30, 2014, 2013 and 2012 consisted primarily of leasehold improvements to the laboratory and
office space at our corporate headquarters and manufacturing facility, laboratory equipment and
computer software applications.

Net cash provided by financing activities was  $9.1 million,  $98.0 million and  $7.0 million for  the

years ended June 30, 2014, 2013 and  2012, respectively, which includes  the proceeds  from the exercise
of 1.1  million, 666,000 and 1.4 million stock  options, respectively. Also, pursuant to public  offerings,  in
fiscal 2013, we issued and sold 6,250,000  shares  of our common stock resulting  in net proceeds of
$94.0 million.

We  anticipate that our current capital resources and expected  future collaborator payments under

existing collaborations will enable us  to  meet our operational expenses and capital expenditures partway
through fiscal year 2016. However, we  cannot provide  assurance that such  collaborative  agreement
funding will, in fact, be received. Should  we or  our partners  not  meet some or  all  of the terms  and
conditions of our various collaboration agreements, we may be required  to pursue additional strategic
partners, secure alternative financing arrangements,  and/or defer  or  limit some  or all of our research,
development and/or clinical projects.

58

Contractual Obligations

Below is a table that presents our contractual  obligations  and commercial  commitments  as of

June 30, 2014 (in thousands):

Payments Due by Period

Total

Less than
One Year

1-3
Years

4-5
Years

More than
5 Years

Waltham lease obligations(1) . . . . . . . . . . .
Other operating lease obligations . . . . . . .

$73,751
4,432

$6,077
1,073

$11,653
2,212

$12,134
1,147

$43,887
—

Total

. . . . . . . . . . . . . . . . . . . . . . . . . . .

$78,183

$7,150

$13,865

$13,281

$43,887

(1) Lease agreements were signed in July 2007,  April  2012 and  April  2013, and amended in

December 2013 and April 2014. In December 2009, we entered into a sublease for  14,100
square feet of our office and laboratory  space at 830 Winter Street, Waltham,  MA through
January 2015. We will receive approximately  $408,000 in minimum  rental payments over  the
remaining term of the sublease, which is not  included in  the table above.

In addition to the above table, we are  contractually obligated to make future success-based

development, regulatory or sales milestone payments  in conjunction with certain  collaborative
agreements. These payments are contingent upon the occurrence of certain future events and, given the
nature of these events, it is unclear when, if ever,  we may  be  required to  pay such amounts. Therefore,
the timing of any future payment is not reasonably estimable.  As a result, these  contingent payments
have not been included in the table above or recorded in our consolidated  financial  statements.

As of June 30, 2014, the maximum amount that may be payable  in the future under  our current
collaborative agreements is $162 million,  $1.4 million of which  is reimbursable by a third party under a
separate agreement.

Recent  Accounting Pronouncements

In May 2014, the FASB issued Accounting Standards Update 2014-9, Revenue from Contracts with

Customers (Topic 606), to clarify the principles for recognizing  revenue. This update provides a
comprehensive new revenue recognition  model  that requires revenue to be recognized  in a manner to
depict the transfer of goods or services to a customer at  an amount that  reflects the consideration
expected to be received in exchange for those goods or  services. This guidance  is effective for annual
reporting and interim periods beginning  after  December 15,  2016 and  allows for either full
retrospective or modified retrospective application, with early  adoption not permitted. Accordingly, the
standard is effective for us on July 1, 2017. We are currently evaluating the  adoption method we will
apply  and the impact that this guidance will have  on our financial  statements and related disclosures.

In July 2013, the FASB issued guidance to address the diversity in practice related to the financial

statement presentation of unrecognized tax  benefits as  either a reduction of a deferred tax  asset or a
liability when a net operating loss carryforward, a similar  tax loss, or a tax  credit carryforward exists.
This guidance is effective prospectively for fiscal years, and interim  periods within those  years,
beginning after December 15, 2013. The adoption of this guidance is not expected  to  have a material
impact on our consolidated financial  statements.

Off-Balance Sheet Arrangements

None.

59

Item 7A. Quantitative and Qualitative Disclosure About  Market Risk

We  maintain an investment portfolio in accordance with our investment policy. The primary

objectives of our investment policy are to preserve  principal, maintain proper liquidity  to  meet
operating needs and maximize yields. Although our  investments are subject to credit  risk, our
investment policy specifies credit quality standards for our investments  and limits the  amount  of credit
exposure from any single issue, issuer or type  of investment. Our investments are  also subject  to
interest rate risk and will decrease in  value  if  market  interest rates  increase. However,  due  to  the
conservative nature of our investments and relatively  short duration, interest rate risk  is mitigated.  We
do not own derivative financial instruments in our investment  portfolio. Accordingly, we do not believe
there is any material market risk exposure  with respect to derivative  or  other financial instruments  that
would require disclosure under this item.

Our foreign currency hedging program uses forward contracts and a Euro-denominated bank
account to manage the foreign currency  exposures that  exist as  part  of  our ongoing business operations.
Our foreign currency risk management  strategy is principally  designed to mitigate the  future potential
financial impact of changes in the value  of transactions, anticipated transactions  and balances
denominated in foreign currency, resulting from  changes in  foreign currency exchange rates.  Our
market risks associated with changes  in  foreign  currency exchange  rates are currently limited to a
Euro-denominated bank account as we  have no forward  contracts  at June 30, 2014.

60

Item 8. Financial Statements and Supplementary  Data

IMMUNOGEN, INC.
INDEX TO CONSOLIDATED FINANCIAL  STATEMENTS

Report of Independent Registered Public Accounting  Firm . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Financial Statements:

Consolidated Balance Sheets as of June 30,  2014 and 2013 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Operations  and  Comprehensive  Loss for the Years  Ended June 30,
2014, 2013, and 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consolidated Statements of Shareholders’ Equity for the Years  Ended  June  30, 2014, 2013,

and 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Cash Flows  for  the Years Ended June  30, 2014, 2013, and  2012 . . .
Notes to Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

62

63

64

65
66
67

61

Report of Independent Registered Public  Accounting Firm

The Board of Directors and Shareholders  of ImmunoGen, Inc.

We  have audited the accompanying consolidated balance sheets of ImmunoGen, Inc.  as of June  30,

2014 and 2013, and the related consolidated  statements  of operations  and  comprehensive loss,
shareholders’ equity, and cash flows for  each of the three years  in the  period ended  June  30, 2014. Our
audits also included the financial statement schedule  listed  in the Index at  Item 15. These financial
statements and schedule are the responsibility of the  Company’s management.  Our responsibility  is to
express an opinion on these financial statements and schedule  based on our audits.

We  conducted our audits in accordance with the standards  of  the Public Company Accounting
Oversight Board (United States). Those  standards require that we  plan and perform the audit to obtain
reasonable assurance about whether  the  financial  statements are free  of material misstatement.  An
audit includes examining, on a test basis, evidence  supporting the amounts and disclosures  in the
financial statements. An audit also includes assessing the accounting  principles used  and significant
estimates made by management, as well as  evaluating the overall financial statement presentation. We
believe that our audits provide a reasonable  basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in all material respects,

the consolidated financial position of  ImmunoGen, Inc.  at June 30,  2014 and  2013, and the
consolidated results of its operations and  its cash  flows  for  each  of the three years in the period ended
June 30, 2014, in conformity with U.S. generally accepted accounting principles.  Also, in our  opinion,
the related financial statement schedule, when considered  in relation to the basic financial statements
taken as a whole, presents fairly in all material  respects the information set forth  therein.

We  also have audited, in accordance  with the standards of  the Public Company Accounting
Oversight Board (United States), ImmunoGen, Inc.’s internal control over financial  reporting as of
June 30, 2014, based on criteria established  in Internal Control—Integrated Framework issued by the
Committee of Sponsoring Organizations  of  the Treadway  Commission (1992 framework) and our report
dated August 28, 2014 expressed an unqualified  opinion thereon.

/s/ Ernst & Young LLP

Boston, Massachusetts
August 28, 2014

62

IMMUNOGEN, INC.

CONSOLIDATED BALANCE SHEETS

In thousands, except per share amounts

ASSETS
Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unbilled revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restricted cash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid and other current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Property and equipment, net of accumulated depreciation . . . . . . . . . . . . . . . .
Long-term restricted cash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

June 30,
2014

June 30,
2013

$ 142,261
1,896
1,329
2,950
—
2,320

150,756
14,349
—
213

$ 194,960
—
2,121
703
319
2,581

200,684
10,783
1,912
217

Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 165,318

$ 213,596

LIABILITIES AND SHAREHOLDERS’ EQUITY
Accounts payable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other accrued liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current portion of deferred lease incentive . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current portion of deferred revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

Total current liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred lease incentive, net of current  portion . . . . . . . . . . . . . . . . . . . . . . .
Deferred revenue, net of current portion . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other long-term liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commitments and contingencies (Note  H)
Shareholders’ equity:
Preferred stock, $.01 par value; authorized 5,000 shares;  no  shares  issued and

4,819
6,865
6,668
528
2,374

21,254
5,679
58,969
3,717

89,619

$

4,498
6,153
6,049
979
1,494

19.173
5,626
63,384
3,566

91,749

outstanding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

—

—

Common stock, $.01 par value; authorized  150,000 shares; issued and
outstanding 85,903 and 84,725 shares as of June  30, 2014 and 2013,
respectively . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Additional paid-in capital
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated deficit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

859
722,971
(648,131)

847
697,767
(576,767)

Total shareholders’ equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

75,699

121,847

Total liabilities and shareholders’ equity . . . . . . . . . . . . . . . . . . . . . . . .

$ 165,318

$ 213,596

The accompanying notes are an integral part of the consolidated financial statements.

63

CONSOLIDATED STATEMENTS OF  OPERATIONS AND COMPREHENSIVE LOSS

In thousands, except per share amounts

IMMUNOGEN, INC.

Year Ended June 30,

2014

2013

2012

Revenues:

License and milestone fees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Royalty revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Research and development support . . . . . . . . . . . . . . . . . . . . . . . .
Clinical materials revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 39,455
10,346
7,187
2,908

$ 24,227
592
7,873
2,843

$ 9,161
—
4,517
2,679

Total revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

59,896

35,535

16,357

Operating Expenses:

Research and development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General and administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

106,958
24,469

87,073
21,471

Total operating expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

131,427

108,544

69,192
20,422

89,614

Loss from operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Investment income, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other income (expense), net

(71,531)
44
123

(73,009)
126
72

(73,257)
66
(128)

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ (71,364) $ (72,811) $(73,319)

Basic and diluted net loss per common share . . . . . . . . . . . . . . . . . .

$

(0.83) $

(0.87) $

(0.95)

Basic and diluted weighted average common shares outstanding . . . . .

85,481

84,063

76,814

Other Comprehensive Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

—

—

—

Total Comprehensive Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ (71,364) $ (72,811) $(73,319)

The accompanying notes are an integral part of the consolidated financial statements.

64

CONSOLIDATED STATEMENTS OF  SHAREHOLDERS’ EQUITY

IMMUNOGEN, INC.

In thousands

Common Stock

Shares

Amount

Balance at June 30, 2011 . . . . . . . . . . . . . . . . .
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock options exercised . . . . . . . . . . . . . . . . . .
Stock-based compensation expense . . . . . . . . . .
Directors’ deferred share units converted . . . . .
Directors’ deferred share unit compensation . . .

76,281
—
1,432
—
46
—

Balance at June 30, 2012 . . . . . . . . . . . . . . . . .

77,759

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock options exercised . . . . . . . . . . . . . . . . . .
Restricted stock award . . . . . . . . . . . . . . . . . .
Stock-based compensation expense . . . . . . . . . .
Issuance of common stock in a public  offering,

—
666
50
—

net of issuance costs . . . . . . . . . . . . . . . . . .
Directors’ deferred share unit compensation . . .

6,250
—

$763
—
14
—
1
—

$778

—
6
—
—

63
—

Additional
Paid-In
Capital

$569,843
—
6,974
9,938
(1)
314

Accumulated
Deficit

$(430,637)
(73,319)
—
—
—
—

Total
Shareholders’
Equity

$139,969
(73,319)
6,988
9,938
—
314

$587,068

$(503,956)

$ 83,890

—
4,020
—
12,400

93,928
351

(72,811)
—
—
—

(72,811)
4,026
—
12,400

—
—

93,991
351

Balance at June 30, 2013 . . . . . . . . . . . . . . . . .

84,725

$847

$697,767

$(576,767)

$121,847

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock options exercised . . . . . . . . . . . . . . . . . .
Stock-based compensation expense . . . . . . . . . .
Directors’ deferred share units converted . . . . .
Directors’ deferred share unit compensation . . .

—
1,134
—
44
—

—
11
—
1
—

—
9,125
15,647
(1)
433

(71,364)
—
—
—
—

(71,364)
9,136
15,647
—
433

Balance at June 30, 2014 . . . . . . . . . . . . . . . . .

85,903

$859

$722,971

$(648,131)

$ 75,699

The accompanying notes are an integral part of the consolidated financial statements.

65

IMMUNOGEN, INC.

CONSOLIDATED STATEMENTS OF CASH FLOWS

In thousands

Cash flows from operating activities:
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustments to reconcile net loss to net  cash used for  operating

activities:
Depreciation and amortization . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loss (Gain) on sale/disposal of fixed assets . . . . . . . . . . . . . . . . . .
(Gain) Loss on forward contracts . . . . . . . . . . . . . . . . . . . . . . . . .
Non-cash licensing fee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock and deferred share unit compensation . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred rent
Change in operating assets and liabilities:

Accounts receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unbilled revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid and other current assets . . . . . . . . . . . . . . . . . . . . . . . .
Restricted cash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts payable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other accrued liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred revenue, net of non-cash upfront license  payment . . . . .
Proceeds from landlord for tenant improvements . . . . . . . . . . . .

Year Ended June 30,

2014

2013

2012

$ (71,364) $ (72,811) $ (73,319)

4,598
20
(2)
12,830
16,080
297

(1,896)
792
(2,247)
571
2,231
4
321
712
(394)
(16,675)
472

4,641
(21)
(197)
—
12,751
(109)

129
(925)
585
(181)
319
(43)
1,103
1,211
481
(7,232)
—

4,633
51
173
—
10,252
(109)

4,539
292
(808)
253
1,018
(16)
182
219
133
18,219
—

Net cash used for operating activities . . . . . . . . . . . . . . . . . . .

(53,650)

(60,299)

(34,288)

Cash flows from investing activities:

Purchases of property and equipment, net . . . . . . . . . . . . . . . . .
(Payments) proceeds from settlement  of forward contracts . . . . .

Net cash used for investing activities . . . . . . . . . . . . . . . . . . .

(8,184)
(1)

(8,185)

(3,770)
74

(3,696)

(2,908)
(60)

(2,968)

Cash flows from financing activities:

Proceeds from stock options exercised . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
Proceeds from common stock issuance, net

Net cash provided by financing activities . . . . . . . . . . . . . . . . .

9,136
—

9,136

4,026
93,991

98,017

6,988
—

6,988

Net change in cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . .
Cash and cash equivalents, beginning  of period . . . . . . . . . . . . . . . . .

(52,699)
194,960

34,022
160,938

(30,268)
191,206

Cash and cash equivalents, end of period . . . . . . . . . . . . . . . . . . . . .

$142,261

$194,960

$160,938

The accompanying notes are an integral part of the consolidated financial statements.

66

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL  STATEMENTS

AS OF JUNE 30, 2014

A. Nature of Business and Plan of Operations

ImmunoGen, Inc. (the Company) was incorporated in Massachusetts in 1981 and is focused on the

development of antibody-based anticancer therapeutics.  The Company has  incurred operating losses
and negative cash flows from operations since inception, incurred a net loss of approximately
$71.4 million during the fiscal year ended  June 30, 2014, and has an accumulated deficit of
approximately $648.1 million as of June  30, 2014. The  Company has primarily funded these  losses
through payments received from its collaborations  and equity financings. To date,  the Company has no
product  revenue and management expects operating losses to continue for the foreseeable future.

At June  30, 2014, the Company had $142.3 million of cash and cash equivalents on hand. The
Company may raise additional funds through equity or  debt financings or generate revenues from
collaborative partners through a combination  of upfront license  payments, milestone payments, royalty
payments, research funding, and clinical  material reimbursement. There can be no assurance that the
Company will be able to obtain additional debt or  equity financing or generate revenues from
collaborative partners on terms acceptable  to  the Company or  at all. The failure of the Company to
obtain sufficient funds on acceptable terms  when needed could have a material adverse effect on the
Company’s business, results of operations  and  financial condition and require the Company  to  defer  or
limit some or all of its research, development and/or clinical projects.

The Company is subject to risks common to companies in  the biotechnology industry including, but
not limited to, the development by its  competitors of  new  technological innovations, dependence on key
personnel, protection of proprietary technology,  manufacturing and marketing limitations, collaboration
arrangements, third-party reimbursements  and compliance with governmental regulations.

B. Summary of Significant Accounting Policies

Principles of Consolidation

The consolidated financial statements include the accounts  of the Company  and its wholly owned

subsidiaries, ImmunoGen Securities Corp., and ImmunoGen Europe Limited. All intercompany
transactions and balances have been eliminated.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted

in the United States (U.S.) requires management  to  make estimates and assumptions that affect the
reported amounts of assets and liabilities and  disclosure  of  contingent assets and liabilities at the date
of the financial statements and the reported amounts of revenues and expenses during the reporting
period. Actual results could differ from those estimates.

Subsequent Events

The Company has evaluated all events or transactions that  occurred after June 30, 2014 up
through the date the Company issued  these financial statements. In  July 2014, Sanofi initiated a
Phase IIb clinical trial for SAR650984 which  triggered a $3 million milestone payment to the Company.
Effective July 2014, Janssen Biotech  (formerly known as Centocor) terminated its exclusive
development and commercialization license with the  Company. As  a result, in July 2014, the Company
recognized the remaining $241,000 of the  $1 million upfront fee received upon execution of the license

67

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

which  had been previously deferred.  The  Company did not have any other material recognizable or
unrecognizable subsequent events.

Revenue Recognition

The Company enters into licensing and development agreements with collaborative partners for
the development of monoclonal antibody-based anticancer therapeutics. The terms of these agreements
contain multiple deliverables which may include (i) licenses, or options to obtain licenses, to the
Company’s antibody-drug conjugate, or  ADC, technology, (ii) rights to future technological
improvements, (iii) research activities  to  be performed on behalf  of  the collaborative partner,
(iv) delivery of cytotoxic agents and (v) the manufacture of preclinical or clinical materials for the
collaborative partner. Payments to the Company under these agreements may include upfront fees,
option fees, exercise fees, payments for research activities,  payments for the  manufacture of preclinical
or clinical materials, payments based upon  the achievement of certain milestones and royalties on
product  sales. The Company  follows the provisions of the  Financial Accounting Standards Board
(FASB) Accounting Standards Codification  (ASC)  Topic 605-25, ‘‘Revenue Recognition—Multiple-
Element Arrangements,’’ and ASC Topic 605-28,  ‘‘Revenue Recognition—Milestone  Method,’’  in
accounting for these agreements. In order  to account for these agreements, the  Company must identify
the deliverables included within the agreement and evaluate  which deliverables  represent separate units
of accounting based on if certain criteria are met, including whether the delivered element has stand-
alone value to the collaborator. The consideration  received is allocated among the  separate units of
accounting, and the applicable revenue  recognition criteria are applied to each of the separate units.

At June  30, 2014, the Company had the following two types of agreements with the parties

identified below:

(cid:127) Development and commercialization licenses  to  use  the Company’s ADC technology and/or

certain  other intellectual property to develop compounds to a specified target antigen (referred
to as development and commercialization licenses, as  distinguished from the Company’s
right-to-test agreements described elsewhere):

Amgen (four exclusive single-target licenses*)

Bayer HealthCare (one exclusive single-target license)

Biotest (one exclusive single-target license)

Lilly (one exclusive single-target license)

Novartis (two exclusive single-target licenses and one license to two related targets: one target
on an exclusive basis and the second target on a  non-exclusive basis)

Roche, through its Genentech unit (five exclusive single-target licenses)

Sanofi (one exclusive single-target license and one  exclusive license to multiple individual
targets) 

* Amgen has sublicensed one of its exclusive single-target licenses to Oxford BioTherapeutics Ltd.

68

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

(cid:127) Option/research agreement for a defined period of time  to  secure development and

commercialization licenses to use the Company’s ADC technology to develop anticancer
compounds to specified targets on established terms  (referred  to  herein as right-to-test
agreements):

Sanofi

Novartis

Lilly

CytomX

There are no performance, cancellation,  termination  or refund provisions in any of the

arrangements that contain material financial consequences to the  Company.

Development and Commercialization  Licenses

The deliverables under a development and commercialization license agreement generally  include
the license to the Company’s ADC technology  with respect to a specified  antigen target, and  may also
include deliverables related to rights  to  future technological improvements, research activities to be
performed on behalf of the collaborative  partner and the manufacture of preclinical or clinical
materials for the collaborative partner.

Generally, development and commercialization licenses  contain non-refundable terms for payments

and, depending on the terms of the agreement, provide  that the Company will (i) at  the collaborator’s
request, provide research services at  negotiated prices which are generally consistent with what  other
third parties would charge, (ii) at the collaborator’s request, manufacture and provide to it preclinical
and clinical materials or deliver cytotoxic  agents at negotiated prices which are  generally consistent with
what other third parties would charge, (iii) earn  payments upon the achievement of certain milestones
and (iv) earn royalty payments, generally until  the later  of  the last applicable  patent  expiration or 10 to
12 years after product launch. In the case of Kadcyla, however, the minimum royalty term  is 10 years
and the maximum royalty term is 12  years on a country-by-country basis, regardless of patent
protection. Royalty rates may vary over  the royalty  term  depending on the  Company’s intellectual
property rights and/or the presence of comparable competing  products. The Company may provide
technical assistance and share any technology improvements with its  collaborators during the term of
the collaboration agreements. The Company does not directly  control when or whether any collaborator
will request research or manufacturing services,  achieve milestones  or become liable for royalty
payments. As a result, the Company cannot  predict when or  if it will recognize revenues in connection
with any of the foregoing.

In determining the units of accounting, management evaluates whether  the license has stand-alone

value from the undelivered elements  to  the collaborative partner based on  the consideration of the
relevant facts and circumstances for each  arrangement.  Factors considered in this determination include
the research capabilities of the partner  and  the availability of ADC technology research expertise  in the
general marketplace. If the Company  concludes that  the license has stand-alone value and therefore
will be accounted for as a separate unit  of accounting,  the Company then determines the estimated
selling prices of the license and all other  units  of  accounting based on market conditions, similar

69

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

arrangements entered into by third parties, and entity-specific factors such as the  terms of the
Company’s previous collaborative agreements, recent preclinical and clinical testing results of
therapeutic products that use the Company’s ADC  technology, the Company’s pricing practices and
pricing objectives, the likelihood that  technological  improvements will be made, and, if made, will be
used by the Company’s collaborators and the nature of the research services to be performed  on behalf
of its collaborators and market rates for  similar services.

Upfront payments on development and commercialization  licenses are deferred if  facts and
circumstances dictate that the license does not have stand-alone value.  Prior to the adoption of
Accounting Standards Update (ASU) No.  2009-13, ‘‘Revenue Arrangements with  Multiple
Deliverables’’ on July 1, 2010, the Company determined that its licenses lacked  stand-alone value and
were combined with other elements of  the arrangement and any amounts associated with the license
were deferred and amortized over a  certain period, which  the Company refers  to  as the Company’s
period of substantial involvement. The  determination of the length of the period over which to defer
revenue is subject to judgment and estimation  and can have an impact on the amount of revenue
recognized in a given period. Historically the Company’s  involvement with the development of a
collaborator’s product candidate has  been significant at the early stages of development, and lessens as
it progresses into clinical trials. Also, as a drug candidate gets closer to commencing pivotal testing the
Company’s collaborators have sought  an  alternative  site to manufacture their products, as the
Company’s facility does not produce  pivotal  or commercial drug product. Accordingly, the Company
generally estimates this period of substantial involvement to begin at the inception of the collaboration
agreement and conclude at the end of  non-pivotal Phase II testing.  The Company believes this  period
of substantial involvement is,  depending on the nature  of the license,  on average six and one-half years.
Quarterly, the Company reassesses its  periods of  substantial involvement over which the Company
amortizes its upfront license fees and  makes  adjustments as appropriate. In the event  a collaborator
elects to discontinue development of a specific product candidate under a development and
commercialization license, but retains  its  right to use the Company’s technology to develop an
alternative product candidate  to the same  target  or a target substitute,  the Company  would cease
amortization of any remaining portion of  the upfront fee until there  is substantial preclinical activity  on
another product candidate and its remaining period of substantial involvement can be estimated. In the
event that a development and commercialization license were to be terminated, the Company would
recognize as revenue any portion of  the upfront fee that  had not previously been recorded  as revenue,
but was classified as deferred revenue,  at the date of such termination.

Subsequent to the adoption of ASU No.  2009-13, the  Company determined that its  research
licenses lack stand-alone value and are considered for  aggregation with the  other elements of  the
arrangement and accounted for as one  unit of accounting.

Upfront payments on development and commercialization  licenses may be recognized  upon

delivery of the license if facts and circumstances dictate  that the  license has stand-alone value from the
undelivered elements, which generally include rights to future  technological improvements, research
services, delivery of cytotoxic agents and the  manufacture of preclinical and clinical materials.

The Company recognizes revenue related to research services that represent  separate units of
accounting as they are performed, as long as  there is persuasive evidence of  an arrangement, the fee is
fixed or determinable, and collection  of the related receivable is probable. The Company  recognizes

70

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

revenue related to the rights to future technological improvements over  the estimated term  of the
applicable license.

The Company may also provide cytotoxic agents  to  its collaborators or  produce preclinical and
clinical materials at negotiated prices which  are generally consistent with what other third parties would
charge. The Company recognizes revenue on cytotoxic agents and  on preclinical and  clinical materials
when the materials have passed all quality testing required for collaborator acceptance and title and
risk of loss have transferred to the collaborator. Arrangement consideration allocated  to  the
manufacture of preclinical and clinical  materials in a multiple-deliverable arrangement is below the
Company’s full cost, and the Company’s full cost  is  not expected to ever be below  its contract selling
prices for its existing collaborations. During the  fiscal  years ended June 30, 2014, 2013 and 2012,  the
difference between the Company’s full cost to manufacture preclinical and clinical materials on behalf
of its collaborators as compared to total amounts received from collaborators for the manufacture of
preclinical and clinical materials was $2.3  million,  $755,000 and $85,000, respectively. The majority of
the Company’s costs to produce these preclinical and clinical materials are fixed and then allocated to
each  batch based on the number of batches produced  during the  period. Therefore, the Company’s
costs to produce these materials are significantly impacted  by the number of batches produced during
the period. The volume of preclinical and clinical materials the Company  produces is directly related to
the number of clinical trials the Company and its collaborators are preparing  for or  currently have
underway, the speed of enrollment in  those trials, the  dosage schedule of each clinical trial and the
time period such trials last. Accordingly,  the volume of preclinical and clinical materials produced, and
therefore the Company’s per-batch costs to manufacture these preclinical  and clinical materials, may
vary significantly from period to period.

The Company may also produce research material for potential collaborators under  material
transfer agreements. Additionally, the  Company performs research activities, including  developing
antibody  specific conjugation processes, on behalf of its collaborators and potential collaborators during
the early evaluation and preclinical testing stages  of drug development. The Company records amounts
received for research materials produced  or  services performed as a component of research and
development support revenue. The Company  also develops conjugation processes  for materials for later
stage testing and commercialization for  certain collaborators. The Company is compensated at
negotiated rates and may receive milestone payments for developing these processes which are
recorded  as a component of research  and development support revenue.

The Company’s development  and commercialization license agreements  have milestone  payments

which  for reporting purposes are aggregated into three categories: (i)  development milestones,
(ii) regulatory milestones, and (iii) sales milestones. Development milestones are typically  payable when
a product candidate initiates or advances into different clinical trial phases.  Regulatory milestones are
typically payable upon submission for  marketing  approval with the U.S. Food  and Drug Administration,
or FDA, or other countries’ regulatory  authorities or on receipt of actual marketing  approvals for the
compound or for additional indications. Sales milestones  are typically  payable when annual  sales reach
certain levels.

At the inception of each agreement that includes  milestone payments, the Company evaluates
whether each milestone is substantive  and at risk  to  both parties on the  basis of the  contingent nature
of the milestone. This evaluation includes  an assessment of whether (a) the consideration is

71

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the
enhancement of the value of the delivered item(s) as a  result of a specific outcome resulting  from the
entity’s performance to achieve the milestone, (b) the  consideration relates solely to past performance
and (c) the consideration is reasonable relative  to  all of the deliverables and payment terms within the
arrangement. The Company evaluates  factors such as  the scientific, regulatory, commercial and other
risks that must be overcome to achieve the respective milestone, the level of effort and investment
required to achieve the respective milestone  and  whether the milestone consideration  is reasonable
relative to all deliverables and payment terms in the  arrangement in making this assessment.

Non-refundable development and regulatory milestones  that are expected to be achieved as a
result of the Company’s efforts during  the period of substantial involvement are considered substantive
and are recognized as revenue upon  the achievement of the milestone, assuming all other revenue
recognition criteria are met. Milestones  that are  not considered substantive because we do not
contribute effort to the achievement  of  such milestones are generally achieved after the period of
substantial involvement and are recognized as revenue upon  achievement of the  milestone, as there are
no undelivered elements remaining and  no continuing performance  obligations, assuming all other
revenue recognition criteria are met.

Under the Company’s development and commercialization license agreements, the Company

receives royalty payments based upon its  licensees’ net  sales of  covered products. Generally, under
these agreements the Company is to receive  royalty  reports and payments from its licensees
approximately one quarter in arrears, that  is, generally in  the second month of the quarter after the
licensee has sold the royalty bearing product or products.  The Company recognizes royalty revenues
when it can reliably estimate such amounts and  collectability is  reasonably assured.  As such, the
Company generally recognizes royalty revenues in the quarter reported to the Company by its licensees,
or one quarter following the quarter  in which sales by the Company’s licensees occurred.

Right-to-Test Agreements

The Company’s right-to-test agreements  provide collaborators the right to (a) test the Company’s

ADC technology for a defined period of time through a research, or right-to-test, license, (b)  take
options, for a defined period of time, to specified targets  and (c) upon exercise of those options, secure
or ‘‘take’’ licenses to develop  and commercialize products for the specified targets on  established terms.
Under these agreements, fees may be  due to the Company (i) at the inception  of the arrangement
(referred to as ‘‘upfront’’ fees or payments), (ii) upon  taking an option with respect to a  specific target
(referred to as option fees or payments earned, if any, when the option is ‘‘taken’’), (iii) upon the
exercise of a previously taken option  to  acquire a  development and commercialization license(s)
(referred to as exercise fees or payments  earned,  if any, when  the development and commercialization
license is ‘‘taken’’), or (iv) some combination of all of these fees.

The accounting for right-to-test agreements  is  dependent on the nature  of the options granted to

the collaborative partner. Options are considered substantive if, at the inception of a right-to-test
agreement, the Company is at risk as  to  whether the  collaborative partner will  choose to exercise  the
options to secure development and commercialization licenses. Factors that are considered  in evaluating
whether options are substantive include the  overall objective of the arrangement,  the benefit the
collaborator might obtain from the agreement without  exercising the options, the  cost to exercise the

72

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

options relative to the total upfront consideration, and  the additional financial commitments or
economic penalties imposed on the collaborator as a  result of exercising the options.

For right-to-test agreements where the options to secure development and commercialization
licenses to the Company’s ADC technology are  considered substantive, the Company does not consider
the development and commercialization licenses to be a  deliverable  at the inception of the agreement.
For those right-to-test agreements entered  into  prior  to  the adoption of ASU No. 2009-13  where the
options to secure development and commercialization licenses are considered substantive, the Company
has deferred the upfront payments received and recognizes this  revenue  over the period during which
the collaborator could elect to take options for  development and commercialization  licenses. These
periods are specific to each collaboration  agreement. If a collaborator takes an option to acquire a
development and commercialization license under these agreements, any substantive option fee is
deferred and recognized over the life  of the option, generally 12 to 18  months. If a collaborator
exercises an option and takes a development and commercialization license to a specific target, the
Company attributes the exercise fee to the  development and commercialization license. Upon exercise
of an option to acquire a development  and commercialization license, the Company would also
attribute any remaining deferred option  fee to the development  and commercialization license and
apply  the multiple-element revenue recognition criteria to the  development and  commercialization
license and any other deliverables to  determine the appropriate revenue recognition, which  will be
consistent with the Company’s accounting policy for upfront payments on single-target licenses. In the
event a right-to-test agreement were  to  be  terminated, the Company would recognize as  revenue any
portion of the upfront fee that had not  previously been  recorded as  revenue, but was classified as
deferred revenue, at the date of such  termination. None of the Company’s  right-to-test agreements
entered into subsequent to the adoption  of ASU No. 2009-13 has been determined to contain
substantive options.

For right-to-test agreements where the options to secure development and commercialization
licenses to the Company’s ADC technology are  not considered substantive, the Company considers the
development and commercialization licenses to be a  deliverable at the inception of the agreement and
applies the multiple-element revenue recognition criteria to determine the appropriate revenue
recognition. None of the Company’s right-to-test agreements entered into prior to the adoption of ASU
No. 2009-13 has been determined to  contain  non-substantive options.

The Company does not directly control  when or  if any collaborator will exercise its options for
development and commercialization licenses. As  a result, the Company cannot predict when or if it will
recognize revenues in connection with any  of the  foregoing.

Inventory

Inventory costs relate to clinical trial materials being manufactured for sale to the Company’s

collaborators. Inventory is stated at the lower of cost  or market as determined on  a first-in,  first-out
(FIFO) basis.

73

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

Inventory at June 30, 2014 and 2013  is  summarized below (in thousands):

Raw materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Work in process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 437
2,513

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$2,950

$ 75
628

$703

June 30,

2014

2013

Raw materials inventory consists entirely of DM1 and  DM4, proprietary cell-killing agents  the
Company developed as part of its ADC technology. All raw materials inventory is currently  procured
from a single supplier.

Work in process inventory consists of  conjugate manufactured for  sale to the  Company’s

collaborators to be used in preclinical and clinical studies.  All conjugate is made  to  order at the request
of the collaborators and subject to the  terms and  conditions of respective  supply agreements. As such,
no excess reserve for work in process inventory is required.

Raw materials inventory cost is stated  net of write-downs of $661,000  and  $810,000 as of June 30,

2014 and June 30, 2013, respectively. The write-downs represent  the cost of raw materials that the
Company considers to be in excess of a twelve-month supply based on firm, fixed orders and
projections from its collaborators as  of  the respective balance  sheet date.

Due to yield fluctuations, the actual amount of  raw materials that will  be  produced in future
periods under third-party supply agreements is  highly uncertain. As such, the amount of  raw materials
produced could be more than is required to support the development  of the Company’s collaborators’
product  candidates. Such excess supply, as determined  under the Company’s inventory reserve policy, is
charged to research and development  expense.

The Company produces preclinical and clinical materials for its  collaborators either in  anticipation

of or in support of preclinical studies  and  clinical trials, or for process  development and analytical
purposes. Under the terms of supply  agreements with its collaborators, the Company generally receives
rolling six-month firm, fixed orders for  conjugate  that the Company  is required  to  manufacture, and
rolling twelve-month manufacturing projections for  the quantity  of conjugate the  collaborator expects to
need in any given twelve-month period. The amount of clinical  material produced is  directly related to
the number of collaborator anticipated or  on-going clinical trials  for which the Company is producing
clinical material, the speed of enrollment  in  those trials, the  dosage schedule of each clinical trial and
the time period, if any, during which patients in the  trial receive clinical benefit from  the clinical
materials. Because these elements are difficult to estimate  over the course of a  trial,  substantial
differences between collaborators’ actual manufacturing orders and their projections could result in the
Company’s usage of raw materials varying  significantly  from estimated usage  at an earlier reporting
period. To the extent that a collaborator has provided  the Company with a firm, fixed order, the
collaborator is required by contract to  reimburse  the Company the  full  negotiated  price of the
conjugate, even if the collaborator subsequently cancels the manufacturing run.

74

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

The Company capitalizes raw material  as inventory upon receipt and accounts for the raw material

inventory as follows:

a)

b)

c)

to the extent that the Company  has up to twelve months of firm, fixed  orders  and/or
projections from its collaborators, the Company capitalizes the  value of raw materials that will
be used in the production of conjugate subject  to  these firm, fixed orders and/or  projections;

the Company  considers more than a  twelve  month supply of raw materials that is not
supported by firm, fixed orders and/or  projections from  its  collaborators to be excess and
establishes a reserve to reduce to zero the value of any such excess raw material inventory
with a corresponding charge to research  and  development expense; and

the Company  also considers any other external factors and information of which it  becomes
aware and assesses the impact of such factors or information on  the net realizable value of the
raw  material inventory at each reporting period.

During  fiscal years 2014, 2013 and 2012,  the Company obtained additional amounts of DMx from
its  supplier which yielded more material  than would be required by  the Company’s collaborators  over
the next twelve months and as a result, the  Company  recorded $364,000,  $798,000 and $748,000
respectively, of charges to research and  development expense related to raw  material  inventory
identified as excess. The Company also recorded $38,000 as research and development expense to write
down certain raw material inventory  to its  net realizable value in  fiscal  year  2012. No similar charges
were recorded during fiscal years 2014 and 2013.  Increases in the Company’s  on-hand supply of raw
materials, or a reduction to the Company’s collaborators’ projections, could result  in significant  changes
in the Company’s estimate of the net  realizable  value of such raw material inventory. Reductions in
collaborators’ projections could indicate  that the Company  has excess raw material inventory and the
Company would then evaluate the need to record  write-downs as charges to research and development
expense.

Unbilled Revenue

The majority of the Company’s unbilled revenue at June 30, 2014 and 2013 represents research

funding earned based on actual resources  utilized under the Company’s various collaborator
agreements.

Restricted Cash

Restricted cash at June 30, 2013 is a cash balance securing irrevocable letters of credit required for
security deposits for the Company’s leased  facilities. This cash  balance security was no longer needed at
June 30, 2014 due to a change in creditors.

75

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

Other Accrued Liabilities

Other accrued liabilities consisted of  the following at June 30, 2014 and 2013 (in thousands):

June 30,

2014

2013

Accrued contract payments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued clinical trial costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued professional services . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued employee benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued public reporting charges . . . . . . . . . . . . . . . . . . . . . . . . .
Other current accrued liabilities . . . . . . . . . . . . . . . . . . . . . . . . . .

$2,914
1,778
833
454
183
506

$2,406
1,849
678
411
179
526

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$6,668

$6,049

Research and Development Expenses

The Company’s research and development expenses are  charged  to  expense as incurred and relate

to (i) research to evaluate new targets  and to develop and evaluate new antibodies, linkers and
cytotoxic agents, (ii) preclinical testing of  its own and, in  certain instances,  its collaborators’ product
candidates, and the cost of its own clinical trials, (iii) development related to clinical and  commercial
manufacturing processes and (iv) manufacturing operations which  also include raw materials. Payments
made by the Company in advance for research  and development  services not yet  provided and/or
materials not yet delivered and accepted  are recorded as prepaid expenses and are included in the
accompanying Consolidated Balance  Sheets as  prepaid  and  other current assets.

Income Taxes

The Company uses the liability method  to  account for income taxes. Deferred  tax assets and
liabilities are determined based on differences between the  financial  reporting and income tax  basis of
assets and liabilities, as well as net operating loss  carry forwards  and tax credits and are measured using
the enacted tax rates and laws that will be in effect  when the  differences  reverse. A valuation allowance
against net deferred tax assets is recorded if, based  on the available  evidence, it  is more likely than  not
that some or all of the deferred tax assets  will not be realized.

Financial Instruments and Concentration of Credit  Risk

Cash and cash equivalents are primarily maintained with  three financial institutions in the  U.S.

Deposits with banks may exceed the amount of insurance provided on such deposits.  Generally,  these
deposits may be redeemed upon demand  and,  therefore, bear minimal  risk. The  Company’s cash
equivalents consist of money market funds with underlying investments  primarily being U.S.
Government-issued securities and high  quality, short-term  commercial paper. Financial instruments that
potentially subject the Company to concentrations  of credit  risk consist principally  of  cash, cash
equivalents and marketable securities.  The Company held no  marketable securities  as of June 30, 2014.
The Company’s investment policy, approved by the Board  of Directors,  limits the amount it may invest
in any one type of investment, thereby  reducing credit  risk  concentrations.

76

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

Derivative instruments include a portfolio of short  duration foreign currency  forward contracts
intended to mitigate the risk of exchange  fluctuations for existing or anticipated receivable  and payable
balances denominated in foreign currency. Derivatives are recorded at fair value and classified as other
current assets or liabilities. The fair value  of these instruments represents  the present value  of
estimated future cash flows under the  contracts, which are a function of underlying interest rates,
currency rates, related volatility, counterparty creditworthiness and duration of the contracts. Changes
in these factors or a combination thereof  may affect the fair value of these instruments.

The Company does not designate foreign  currency forward contracts as hedges for accounting
purposes, and changes in the fair value of  these instruments are recognized in  earnings during the
period of change. Because the Company  enters into forward contracts  only as an economic hedge, any
gain or loss on the underlying foreign-denominated  existing or  anticipated  receivable or payable
balance would be offset by the loss or  gain on the forward contract.  Net gains (losses) on  forward
contracts for the years ended June 30,  2014, 2013 and 2012 were $2,000, $197,000 and $(173,000),
respectively, and are included in the accompanying Consolidated Statement of Operations as other
income (expense), net. As of June 30, 2014, the Company had no outstanding forward contracts. As of
June 30, 2013, the Company had an outstanding forward contract with  a notional amount equivalent  to
approximately $57,000 (A41,000), maturing on October 7, 2013. The Company does not  anticipate using
derivative instruments for any purpose  other than hedging exchange rate exposure.

Cash Equivalents

All highly liquid financial instruments  with  maturities of three months or less when purchased are

considered cash equivalents. As of June  30, 2014 and 2013, cash equivalents consisted  of money market
funds  with underlying investments primarily  being U.S.  Government-issued securities and high quality,
short-term commercial paper.

Fair Value of Financial Instruments

ASC Topic 820 defines fair value, establishes  a framework for measuring fair value in accordance

with accounting principles generally accepted in the U.S., and  expands disclosures about fair value
measurements. Fair value is defined under ASC Topic 820 as the exchange price that would be received
for an asset or paid to transfer a liability (an exit price) in  the principal or  most advantageous market
for the asset or liability in an orderly  transaction between market participants on the measurement
date.  Valuation techniques used to measure fair value  must maximize the  use of observable inputs and
minimize the use of unobservable inputs.  The standard  describes a fair value hierarchy to measure fair
value which is based on three levels of  inputs, of which  the first two are considered observable and  the
last unobservable, as follows:

(cid:127) Level 1—Quoted prices in active markets  for identical  assets  or liabilities.

(cid:127) Level 2—Inputs other than Level 1  that are observable, either directly  or indirectly, such as
quoted prices for similar assets or liabilities; quoted  prices in markets that  are not active; or

77

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

other inputs that are observable or can be corroborated  by observable market data for
substantially the full term of the assets  or liabilities.

(cid:127) Level 3—Unobservable inputs that  are  supported by little or no  market  activity and that are

significant to the fair value of the assets or liabilities.

As of June 30, 2014, the Company held certain assets  that are required to be measured  at fair

value on  a recurring basis. The following  table  represents  the fair value hierarchy for the Company’s
financial assets measured at fair value on a recurring basis as of  June 30, 2014 (in thousands):

Fair Value Measurements at June 30, 2014 Using

Quoted Prices in
Active Markets for
Identical Assets

Significant Other
Observable Inputs

Significant
Unobservable
Inputs

Total

(Level 1)

(Level 2)

(Level 3)

Cash and cash equivalents . . . . . . . . . . . . .

$142,261

$142,261

$—

$—

As of June 30, 2013, the Company held certain assets  that  are required to be measured  at fair

value on  a recurring basis. The following  table represents  the fair  value hierarchy for the Company’s
financial assets measured at fair value on a recurring  basis as of  June  30, 2013 (in thousands):

Fair Value Measurements at June 30, 2013 Using

Quoted Prices in
Active Markets for
Identical Assets

Significant Other
Observable Inputs

Significant
Unobservable
Inputs

Total

(Level 1)

(Level 2)

(Level 3)

Cash, cash equivalents and restricted cash .

$197,191

$197,191

$—

$—

The fair value of the Company’s cash equivalents  is based primarily on quoted  prices from active

markets.

The carrying amounts reflected in the consolidated balance sheets for accounts  receivable, unbilled
revenue, prepaid and other current assets, accounts  payable, accrued compensation,  and other accrued
liabilities approximate fair value due  to  their  short-term nature.

Property and Equipment

Property and equipment are stated at  cost. The Company  provides for depreciation  based upon

expected useful lives using the straight-line  method over the  following  estimated useful lives:

Machinery and equipment . . . . . . . . . .
Computer hardware and software . . . . .
Furniture and fixtures . . . . . . . . . . . . .
Leasehold improvements . . . . . . . . . . .

5 years
3 years
5 years
Shorter of remaining lease term or 7 years

Equipment under capital leases is amortized  over the lives  of  the respective  leases or the estimated

useful lives of the assets, whichever is shorter, and included in  depreciation  expense.

78

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

Maintenance and repairs are charged to expense as incurred. Upon retirement or sale, the cost  of

disposed assets and the related accumulated depreciation  are removed from  the accounts and any
resulting gain or loss is included in the statement of  operations. The Company recorded $(20,000),
$21,000 and $(51,000) of (losses) gains on the sale/disposal of certain  furniture and equipment during
the years ended June 30, 2014, 2013,  and  2012, respectively.

Impairment of Long-Lived Assets

In accordance with ASC Topic 360, ‘‘Property, Plant, and Equipment,’’ the Company  continually
evaluates whether events or circumstances  have  occurred that indicate that the estimated remaining
useful life of its long-lived assets may warrant  revision or  that the carrying value of these assets  may be
impaired. The Company evaluates the realizability  of its  long-lived assets  based on cash flow
expectations for the related asset. Any write-downs  are treated as permanent reductions in  the carrying
amount of the assets. Based on this evaluation, the  Company believes that, as of each  of the balance
sheet dates presented, none of the Company’s long-lived assets were impaired.

Computation of Net Loss per Common Share

Basic and diluted net loss per share is  calculated based upon the weighted average number of

common shares outstanding during the period. During periods of income, participating securities are
allocated a proportional share of income  determined  by dividing total weighted average participating
securities by the sum of the total weighted average  common shares and  participating  securities (the
‘‘two-class method’’). The Company’s  restricted stock participates in  any dividends that may  be  declared
by the Company and are therefore considered  to  be  participating  securities. Participating securities have
the effect of diluting both basic and diluted  earnings per share  during periods  of income. During
periods of loss, no loss is allocated to  participating  securities since they have no contractual obligation
to share in the losses of the Company. Diluted (loss) income per share is  computed  after giving
consideration to the dilutive effect of  stock  options  that are outstanding  during the period, except
where  such non-participating securities would be anti-dilutive.

The Company’s common stock equivalents,  as calculated in accordance with  the treasury-stock

method, are shown in the following table  (in thousands):

June 30,

2014

2013

2012

Options outstanding to purchase common stock and unvested
restricted stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common stock equivalents under treasury stock method . . . .

8,486
1,820

7,703
2,149

6,442
2,194

The Company’s common stock equivalents  have not been included in the  net loss  per  share

calculation because their effect is anti-dilutive  due  to  the Company’s net  loss position.

Stock-based Compensation

As of June 30, 2014, the Company is  authorized to grant future awards under one employee  share-

based compensation plan, which is the  ImmunoGen, Inc.  2006 Employee, Director and Consultant

79

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

Equity Incentive Plan, or the 2006 Plan.  At the  annual meeting of shareholders  on November 13, 2012,
an amendment to the 2006 Plan was approved and  an additional 3,500,000 shares were authorized  for
issuance under this plan. As amended, the 2006 Plan provides  for the issuance of Stock Grants, the
grant of Options and the grant of Stock-Based Awards  for up to 12,000,000 shares of the Company’s
common stock, as well as any shares of common  stock that are represented by awards granted under
the previous stock option plan, the ImmunoGen, Inc. Restated Stock  Option Plan, or the Former Plan,
that are forfeited, expire or are cancelled without delivery of shares of common stock; provided,
however, that no more than 5,900,000 shares shall  be  added to the  2006 Plan from the Former Plan,
pursuant to this provision. Option awards  are granted with  an exercise price equal to the market price
of the Company’s stock at the date of grant.  Options vest  at various  periods of  up to four years and
may be exercised within ten years of  the date of grant.

The stock-based awards are accounted for under  ASC  Topic 718, ‘‘Compensation—Stock

Compensation.’’ Pursuant to Topic 718,  the estimated grant date fair value of awards is charged to the
statement of operations over the requisite  service period,  which is the vesting period. Such amounts
have been reduced by an estimate of  forfeitures  of all unvested awards. The fair value of each stock
option is estimated on the date of grant  using the Black- Scholes option-pricing model with the
weighted average assumptions noted  in  the following table. As the Company has not paid dividends
since inception, nor does it expect to pay any dividends  for the foreseeable  future, the expected
dividend yield assumption is zero. Expected volatility is based  exclusively on historical  volatility  data  of
the Company’s stock. The expected term of stock options granted is  based exclusively on historical data
and represents the period of time that stock options  granted  are expected to be outstanding. The
expected term is calculated for and applied to one group of stock options as the  Company does not
expect substantially different exercise or  post-vesting termination behavior amongst its employee
population. The risk-free rate of the stock  options  is based on the U.S. Treasury rate in  effect at the
time of grant for the expected term of the stock  options.

Year Ended June 30,

2014

2013

2012

Dividend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . None
Volatility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Risk-free interest rate . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected life (years) . . . . . . . . . . . . . . . . . . . . . . . . . . . .

60.44% 60.44% 59.70%
1.74% 0.87% 2.16%
6.3
6.3

7.1

None

None

Using the Black-Scholes option-pricing  model, the  weighted average grant  date fair  values  of

options granted during fiscal years 2014,  2013 and 2012 were  $10.50, $8.60,  and $9.00  per  share,
respectively.

80

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

A summary of option activity  under the 2006 Plan as of  June 30, 2014, and changes during the

twelve month period then ended is presented below (in thousands, except weighted-average data):

Outstanding at June 30, 2013 . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . .
Exercised . . . . . . . . . . . . . . . . . . . . . . .
Forfeited/Canceled . . . . . . . . . . . . . . . . .

Number of
Stock
Options

7,653
2,391
(1,134)
(461)

Outstanding at June 30, 2014 . . . . . . . . .

8,449

Outstanding at June 30, 2014—vested  or

unvested and expected to vest . . . . . . .

Exercisable at June 30, 2014 . . . . . . . . . .

8,233

4,637

Weighted- Weighted-
Average
Average
Remaining
Exercise
Life in Yrs
Price

Aggregate
Intrinsic
Value

$10.79
$18.18
$ 8.05
$16.70

$12.93

$12.83

$ 9.79

6.88

$14,351

6.82

5.48

$14,346

$14,211

In November 2012, the Company granted  an officer of the  Company 50,000 shares of restricted
stock upon hire. Pursuant to the agreement, the shares vest ratably in quarterly  installments  over the
subsequent four years. The fair value of  the restricted  stock was determined by the  closing  price on  the
date  of  grant. A summary of restricted stock activity  under the 2006 Plan as of June 30,  2014, and
changes during the twelve month period  then ended is  presented  below (in thousands,  except weighted-
average data):

Unvested at June 30, 2013 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vested . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

50,000
(12,500)

Unvested at June 30, 2014 . . . . . . . . . . . . . . . . . . . . . . . . . . .

37,500

Number of
Restricted
Stock

Weighted-
Average
Exercise
Price

$11.93
$11.93

$11.93

Stock compensation expense related to stock options and restricted stock  awards  granted under  the
2006 Plan was $15.6 million, $12.4 million  and $9.9 million  during  the fiscal years ended June 30,  2014,
2013, and 2012, respectively. As of June  30, 2014, the estimated  fair value of unvested  employee awards
was approximately $22.2 million, net  of  estimated  forfeitures. The  weighted-average remaining vesting
period for these awards is approximately  two years.

81

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

A summary of option activity  for options  vested  during the fiscal years ended June 30, 2014,  2013

and 2012 is presented below (in thousands):

Total fair value of options vested . . . . . . . . . . . . . . . . .
Total intrinsic value of options exercised . . . . . . . . . . . .
Cash received for exercise of stock options . . . . . . . . . .

$12,535
9,961
9,136

$9,670
6,737
4,026

$ 5,647
12,476
6,988

Year Ended June 30,

2014

2013

2012

Comprehensive Loss

The Company presents comprehensive loss  in accordance with ASC Topic 220, Comprehensive
Income. Comprehensive loss is comprised of the  Company’s  net loss  for the  years  ended June 30, 2014,
2013 and 2012.

Segment Information

During  the three fiscal years ended June 30, 2014,  the Company continued to operate in  one
reportable business segment under the management approach of ASC Topic 280, Segment Reporting,
which  is the business of discovery of monoclonal antibody-based anticancer therapeutics.

The percentages of revenues recognized from  significant customers of  the  Company in  the years

ended June 30, 2014, 2013 and 2012  are  included in  the following table:

Collaborative Partner:

Year Ended
June 30,

2014

2013

2012

Amgen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6% 6% 30%
Bayer HealthCare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . —% 4% 15%
3% 5% 14%
Biotest
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18% 2% 2%
Lilly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38% 49% 16%
Novartis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34% 30% —%
Roche . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1% 3% 23%
Sanofi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

There were no other customers of the Company  with significant revenues  in the years ended

June 30, 2014, 2013 and 2012.

Recent Accounting Pronouncements

In May 2014, the FASB issued Accounting Standards Update 2014-9, Revenue from Contracts with

Customers (Topic 606), to clarify the principles for recognizing  revenue. This update provides a
comprehensive new revenue recognition  model  that requires revenue to be recognized  in a manner to
depict the transfer of goods or services to a customer at  an amount that  reflects the consideration
expected to be received in exchange for those goods or  services. This guidance  is effective for annual
reporting and interim periods beginning  after  December 15,  2016 and  allows for either full

82

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

B. Summary of Significant Accounting Policies (Continued)

retrospective or modified retrospective application, with  early  adoption not permitted. Accordingly, the
standard is effective for the Company  on July 1, 2017. The Company is currently evaluating the
adoption method it will apply and the impact that  this guidance  will have on  our financial statements
and related disclosures.

In July 2013, the FASB issued guidance to address the diversity in practice related to the financial

statement presentation of unrecognized tax  benefits as either a reduction of a deferred tax  asset or a
liability when a net operating loss carryforward, a similar  tax loss, or a tax credit carryforward exists.
This guidance is effective prospectively for fiscal years, and interim periods within those years,
beginning after December 15, 2013. The adoption of this guidance is not expected to have a material
impact on the Company’s consolidated financial statements.

C. Agreements

Significant Collaborative Agreements

Roche

In May 2000, the Company granted Genentech, now a unit of Roche, an exclusive license to use
the Company’s maytansinoid ADC technology with antibodies, such as trastuzumab, or other proteins
that target HER2. Under the terms of this  agreement, Roche has  exclusive  worldwide rights to develop
and commercialize maytansinoid ADC compounds  targeting HER2. In  February 2013, the  US FDA
granted marketing approval to the HER2-targeting ADC  compound, Kadcyla. Roche received
marketing approval for Kadcyla in Japan and in the European Union (EU) in September 2013  and
November 2013, respectively. They have  also received  marketing  approval in various other countries
around the world. Roche is responsible for  the manufacturing, product development  and marketing of
any products resulting from the agreement. The  Company is compensated for any preclinical and
clinical materials that the Company manufactures under the agreement. The Company received  a
$2 million non-refundable upfront payment from  Roche upon execution of the  agreement. The
Company is also entitled to receive up to a total of $44  million in  milestone payments, plus royalties on
the commercial sales of Kadcyla or any  other resulting products. Total milestones are categorized as
follows: development milestones—$13.5 million; and regulatory milestones—$30.5 million. Through
June 30, 2014, the Company has received and recognized $13.5 million and $20.5 million in
development and regulatory milestone payments, respectively, related to Kadcyla. The US marketing
approval of Kadcyla in February 2013 triggered a  $10.5 million regulatory milestone  payment to the
Company, which is included in license and milestone fees for the fiscal year ended  June 30, 2013 The
Company received two $5 million regulatory milestone payments in connection  with marketing approval
of Kadcyla in Japan and in the EU, which is included in  license and milestone fees for the fiscal  year
ended June 30, 2014 Based on an evaluation of the  effort contributed to the achievement of these
milestones in fiscal years 2014 and 2013, the Company determined these milestones were not
substantive. In consideration that there were no undelivered elements remaining, no  continuing
performance obligations and all other revenue recognition criteria had been met, the Company
recognized the non-refundable payments as  revenue  upon achievement of the milestones. The next
potential milestone the Company will be entitled to receive  will be a $5 million regulatory milestone for
marketing approval of Kadcyla for a first  extended indication as defined in  the agreement. Based on an

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evaluation of the effort contributed towards the achievement of this  future milestone, the Company
determined this milestone is not substantive.

The Company receives royalty reports and payments related  to  sales of  Kadcyla from Roche one
quarter in arrears. In accordance with  our  revenue recognition policy, $10.3 million of royalties on net
sales of Kadcyla for the twelve-month  period ended  March 31, 2014 were recorded and included in
royalty revenue for the year ended June 30, 2014.  The Company recorded $592,000 of royalties on net
sales of Kadcyla for the three-month  period  ended March  31, 2013 in its fourth quarter of fiscal 2013.
No royalty revenue was recorded in fiscal  year 2012.

Roche, through its Genentech unit, also has licenses for the exclusive right to use the Company’s
maytansinoid ADC technology with antibodies to four undisclosed targets, which were granted under
the terms of a separate May 2000 right-to-test agreement  with  Genentech. For each  of these  licenses
the Company received a $1 million license  fee and  is  entitled to receive up to a total of $38 million in
milestone payments and also royalties on  the sales of any resulting  products. The total milestones are
categorized as follows: development milestones—$8  million; regulatory milestones—$20 million; and
sales milestones—$10 million. The Company has not received any milestone payments  from these
agreements through June 30, 2014. Roche is  responsible for the development, manufacturing, and
marketing of  any products resulting from  these licenses.  The next potential milestone the Company will
be entitled to receive under any of these agreements  will be a development milestone for filing of an
IND application which will result in a $1  million payment being due. At the  time of execution  of each
of these  development and commercialization licenses, there was significant uncertainty as to whether
this  milestone would be achieved. In consideration of this,  as well as the  Company’s past involvement
in the research and manufacturing these  products, this  milestone was deemed substantive. Roche no
longer has the right to take additional  licenses under the  right-to-test agreement. The Company
received non-refundable technology access  fees  totaling $5 million  for the eight-year term  of the
right-to-test agreement. The upfront fees were deferred and recognized ratably over the period during
which  Genentech could elect to obtain product  licenses.

Amgen

Under a now-expired right-to-test agreement, in September 2009, November 2009 and December

2012, Amgen took three exclusive development and commercialization licenses, for which the Company
received an exercise fee of $1 million for  each license taken. In May 2013, Amgen took one
non-exclusive development and commercialization license,  for which the Company received an exercise
fee of $500,000. In October 2013, the non-exclusive license was amended and  converted  to  an exclusive
license, for which Amgen paid an additional  $500,000 fee to the Company. Amgen has sublicensed its
rights under this license to Oxford BioTherapeutics Ltd. For each development and commercialization
license taken, the Company is entitled to receive up to a total of $34  million  in milestone payments,
plus royalties on the commercial sales  of  any  resulting  products.  The total milestones per license are
categorized as follows: development milestones—$9  million; regulatory milestones—$20 million; and
sales milestones—$5 million. Amgen  (or  its  sublicensee(s)) is  responsible for the manufacturing,
product  development and marketing  of any products resulting from these development and
commercialization licenses.

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C. Agreements (Continued)

Since a deliverable to the original right-to-test  agreement was determined to be materially
modified at the time the non-exclusive  license  was  converted to exclusive in October 2013, the
Company accounted for the multiple-element agreement in  accordance with ACS 605-25 (as amended
by ASU No. 2009-13). As a result, all  of the  deferred revenue recorded on the date of the modification
and the new consideration received as  part of the modification was allocated to all of the remaining
deliverables at the  time of amendment of the right-to-test agreement  based on the estimated selling
price of each element. The remaining amount represents consideration  for previously delivered
elements and was recognized upon the  execution of the  modification.

The outstanding licenses, including the exclusive license delivered upon the  signing of the
amendment, contain the rights to future  technological improvements as well as options  to  purchase
materials and research and development  services. The Company concluded  that  additional materials
and research and development services would be paid at a contractual price  equal to the estimated
selling price based estimated prices that would be charged by third parties for similar  services. The
estimated selling price of the right to  technological improvements is the Company’s best estimate of
selling price and was determined by estimating the probability that  technological improvements will  be
made and the probability that such technological improvements made will be used by Amgen. In
estimating these probabilities, we considered  factors such as the technology that is the  subject of the
development and commercialization licenses, our history of making technological improvements,  and
when such improvements, if any, were likely to occur relative to the  stage of development of any
product  candidates pursuant to the development and  commercialization  licenses. The  Company’s
estimate of probability considered the  likely period of time that any improvements would be utilized,
which  was estimated to be ten years following delivery of a  commercialization and development license.
The value of any technological improvements  made available after this ten year  period was considered
to be de minimis due to the significant additional costs that would  be  incurred to incorporate such
technology into any existing product candidates.  The estimate of probability was multiplied by the
estimated selling price of the development and commercialization licenses and the resulting cash flow
was discounted at a rate of 13%, representing the  Company’s estimate of its cost  of capital at  the time
of amendment of the right-to-test agreement.

The $430,000 determined to be the estimated selling price of the future technological

improvements is being recognized as  revenue ratably over the period  the Company  is obligated to make
available any technological improvements,  which is  equivalent to the estimated term of  the agreement.
The Company estimates the term of  a development and  commercialization  license to be approximately
25 years, which reflects management’s  estimate  of  the time necessary to develop and commercialize
products pursuant to the license plus the  estimated  royalty term. The Company reassesses the  estimated
term at the end of each reporting period.

After accounting for the undelivered  elements at the estimated selling price, the Company  had
$2.2 million of remaining allocable consideration which was determined to represent consideration for
the previously delivered elements, including  the exclusive license that was delivered upon the execution
of the modification. This amount was  recorded  as revenue  and is included in license  and milestone fees
for the year ended June 30, 2014.

In November 2011, the IND applications to the FDA  for two compounds developed under the
2009 development and commercialization licenses became effective, which triggered two $1 million

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C. Agreements (Continued)

milestone payments to the Company. These payments are  included in license and milestone fees for the
year ended June 30, 2012. The next potential  milestone  the Company will be entitled to receive under
the 2009 development and commercialization licenses will be a development milestone for the first
dosing of a patient in a Phase II clinical  trial,  which will result in  a $3 million payment being due. The
next potential milestones the Company will be entitled to receive under the December 2012 and May
2013 development and commercialization licenses will be a $1 million  development milestone for an
IND becoming effective. At the time  of execution  of  each of these development and  commercialization
licenses, there was significant uncertainty  as to whether these milestones would be achieved. In
consideration of this, as well as the Company’s  past  involvement in the research and manufacturing of
these product candidates, these milestones were deemed substantive.

Costs directly attributable to the Amgen collaborative agreement are comprised of compensation
and benefits related to employees who provided research and development services on behalf of Amgen
as well as costs of clinical materials sold. Indirect  costs are  not  identified to individual collaborators.
The costs related to the research and  development services  amounted to approximately $179,000,
$174,000 and $423,000 for fiscal years  2014, 2013 and 2012, respectively. The costs related to clinical
materials  sold  were  approximately  $664,000,  $670,000  and  $649,000  for  fiscal  years  2014,  2013  and  2012,
respectively.

Sanofi

In July 2003, the Company entered into a broad collaboration agreement  with Sanofi  (formerly
Aventis) to discover, develop and commercialize  antibody-based  products. The  collaboration agreement
provides Sanofi with worldwide development and  commercialization  rights to new antibody-based
products directed to targets that are included in the collaboration, including the exclusive right to use
the Company’s maytansinoid ADC technology in the  creation of products developed to these targets.
The product candidates (targets) as of  June 30, 2014  in  the collaboration  include SAR3419 (CD19),
SAR650984 (CD38), SAR566658 (CA6),  SAR408701 (CEACAM5) and one earlier-stage compound
that has yet to be disclosed.

The Company is entitled to receive milestone payments potentially totaling $21.5 million,  per
target, payments, plus royalties on the commercial sales of any resulting products.  The total milestones
are categorized as follows: development  milestones—$7.5 million;  and regulatory milestones—
$14 million. Through June 30, 2014,  the  Company  has received  and recognized an  aggregate of
$16.5 million in milestone payments for  compounds covered under this agreement now or  in the past,
including a $500,000 development milestone  related to an  undisclosed  target which is included  in
license and milestone fee revenue for the year ended  June 30, 2013 and a $3 million  milestone payment
related to the initiation of a Phase IIb  clinical trial (as defined in the agreement) for SAR3419, which
is included in license and milestone fee  revenue for  the year  ended June 30, 2012. In  July 2014, Sanofi
initiated a Phase II clinical trial for SAR650984 which triggered a $3 million payment to the Company.
The next potential milestone the Company will be entitled to receive with respect to SAR566658 will
be a development milestone for initiation of a Phase  IIb clinical trial (as  defined in the agreement),
which  will result in a $3 million payment  being  due. The next potential milestone the Company will be
entitled to receive with respect to both  SAR3419  and SAR650984 will be  for initiation of a Phase III
clinical trial, which will result in each  case  in a $3  million payment being due. The next potential
milestone the Company will be entitled  to  receive for each  of  SAR408701 and the unidentified target

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C. Agreements (Continued)

will be a development milestone for commencement  of  a Phase I clinical  trial, which will result in each
case in a  $1 million payment being due. At  the time of execution of this agreement,  there was
significant uncertainty as to whether  these  milestones would be achieved. In consideration of this, as
well as the Company’s past involvement in the research  and manufacturing of  these product candidates,
these milestones were deemed substantive.

In December 2006, the Company entered into a right-to-test agreement with Sanofi. The

agreement provides Sanofi with the right  to (a) test the Company’s maytansinoid  ADC technology with
Sanofi’s antibodies to targets under a  right-to-test, or research, license, (b) take exclusive options, with
certain restrictions, to specified targets for specified option periods and (c) upon exercise  of those
options, take exclusive licenses to use  the  Company’s maytansinoid  ADC technology  to  develop  and
commercialize products directed to the  specified targets  on terms agreed upon at the inception of the
right-to-test agreement. For each development  and  commercialization license  taken, the  Company is
entitled to receive an exercise fee of  $2 million and  up  to  a total of $30 million in milestone payments,
plus royalties on the commercial sales  of  any  resulting  products.  The total milestones are categorized as
follows: development milestones—$10 million; and regulatory milestones—$20 million.

In December 2013, Sanofi took its first exclusive development and commercialization license under

the right-to-test agreement, for which  the Company received an  exercise fee  of $2 million. The
Company has deferred the exercise fee and  is  recognizing the $2 million as revenue ratably  over the
Company’s estimated period of its substantial involvement. The next payment the Company could
receive would either be a $2 million development  milestone payment with the initiation  of a Phase  I
clinical trial under the first development and commercialization license  taken,  or a $2 million exercise
fee for the execution of a second license.  At  the time  of  execution of this agreement, there was
significant uncertainty as to whether  the  milestone related to initiation of  a Phase I clinical trial under
the first development and commercialization license  would be achieved. In consideration of this, as well
as the Company’s  expected involvement in the research  and manufacturing of  these product candidates,
this  milestone was deemed substantive. Sanofi is responsible for the manufacturing, product
development and marketing of any products resulting from the agreement.

In addition to the $2 million exercise fee  received for the development and commercialization
license taken, the Company received upfront payments of $4 million under  the right-to-test agreement,
of which $500,000 was received in December  2006 upon execution of the agreement and $3.5 million
was received in August 2008 upon Sanofi’s activation of its rights under the  agreement. The
right-to-test agreement had a three-year original term from the  activation date and was renewed by
Sanofi in August 2011 for its final three-year term by  payment of a $2 million fee.  The Company has
deferred the $2 million extension fee  and  is recognizing  this  amount as revenue over the period during
which  Sanofi  can take additional options  for development and commercialization licenses.

Biotest

In July 2006, the Company granted Biotest an  exclusive  development and commercialization
license to our maytansinoid ADC technology for  use with antibodies that target  CD138. The product
candidate BT-062 is in development under this  agreement. Biotest is responsible for the manufacturing,
product  development and marketing  of any products resulting from the agreement. The Company
received a $1 million upfront payment upon  execution of the agreement  and could receive up to

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C. Agreements (Continued)

$35.5 million in milestone payments, as  well as royalties  on  the commercial sales of any resulting
products. The total milestones are categorized  as  follows: development milestones—$4.5 million;  and
regulatory milestones—$31 million. The Company receives payments for manufacturing any preclinical
and clinical materials made at the request  of Biotest. In September 2008,  Biotest began Phase I
evaluation of BT062 which triggered a  $500,000 milestone payment to the  Company. The next  potential
milestone we will be entitled to receive  will  be  a development milestone for commencement of a
Phase IIb clinical trial (as defined in the agreement) which will  result in a $2 million payment being
due. At the time of execution of this agreement, there was significant uncertainty as to whether  these
milestones would be achieved. In consideration of this,  as well as  the Company’s past involvement in
the research and manufacturing of this  product, these milestones were deemed substantive.

The agreement also provided the Company with the right to elect at specific  stages during the

clinical evaluation of any compound  created  under this agreement, to participate in the U.S.
development and commercialization of that compound in  lieu of receiving  the milestone payments not
yet earned and royalties on sales in the U.S. Currently, the Company  can exercise  this right during an
exercise period specified in the agreement by notice  and  payment to Biotest of an agreed  upon opt-in
fee of $15 million. Upon exercise of  this right, the Company would share equally with Biotest the
associated further costs of product development and  commercialization  in the U.S. along with the
profit, if any, from product sales in the  U.S.  The Company  would also be  entitled to receive royalties,
on a reduced basis, on product sales  outside the  U.S.

Costs directly attributable to the Biotest  collaborative agreement are  comprised of compensation
and benefits related to employees who provided research and development services on behalf of Biotest
as well as costs of clinical materials sold. Indirect  costs are  not  identified to individual collaborators.
The costs related to the research and  development services  amounted to approximately $305,000,
$339,000 and $233,000 for fiscal years  2014, 2013 and 2012, respectively. The costs related to clinical
materials sold were approximately $670,000, $577,000 and $1.3 million for fiscal years 2014, 2013 and
2012, respectively.

Bayer HealthCare

In October 2008, the Company granted Bayer HealthCare an exclusive development and

commercialization license to the Company’s  maytansinoid ADC technology for use with  antibodies or
other proteins that target mesothelin. Bayer  HealthCare is responsible for the  research,  development,
manufacturing and marketing of any products resulting from the license. The Company received a
$4 million upfront payment upon execution  of the agreement, and—for  each compound developed and
marketed by Bayer HealthCare under  this  collaboration—the Company is  entitled to receive a total of
$170.5 million in milestone payments, plus royalties  on the commercial sales of any resulting  products.
The total milestones are categorized  as follows: development milestones—$16 million; regulatory
milestones—$44.5 million; and sales milestones—$110 million. Through June 30,  2014, the Company
has received and recognized an aggregate  of  $3 million in milestone payments under this agreement. At
the time of execution of this agreement, there was  significant uncertainty as to whether these received
and recognized milestones would be achieved. In  consideration of this, as well as the Company’s past
involvement in the research and supply  of  cytotoxic agent for this product candidate, these milestones
were deemed substantive. The next potential  milestone the Company will be entitled to receive will be
a development milestone for commencement of  a non-pivotal Phase II  clinical trial, which will result in

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C. Agreements (Continued)

a $4 million payment being due. At the  time  of execution of this agreement, there was significant
uncertainty as to whether this milestone would be achieved. In consideration  of this,  as well as the
Company’s past involvement in the research and supply of  cytotoxic agent for this product candidate,
this  milestone was deemed substantive.

The Company had previously deferred the  $4  million upfront payment received  and was

recognizing this amount as revenue ratably over the  estimated period of substantial  involvement. The
Company had previously estimated this  development period would  conclude at the  end of non-pivotal
Phase II testing. During the first quarter of  fiscal  2012, Bayer HealthCare initiated Phase I clinical
testing of its product candidate. In reaching this stage  of clinical testing, Bayer  HealthCare developed
its  own processes for manufacturing required clinical material  and produced clinical material in its own
manufacturing facility. Considering that Bayer HealthCare was able to accomplish this without
significant reliance on the Company,  and  considering that the Company’s expected future involvement
would be primarily supplying  Bayer HealthCare with small quantities of cytotoxic agents for a limited
period of time, the Company believed its period of  substantial involvement would end prior to the
completion of non-pivotal Phase II testing. As a result  of this determination,  beginning  in September
2011, the Company recognized the balance of the upfront payment as  revenue ratably through
September 2012. This change in estimate resulted in an increase to license and milestone fees of
approximately $1.2 million for the fiscal  year ending June 30,  2012 compared to amounts that would
have been recognized pursuant to the  Company’s previous  estimate. Costs directly attributable to the
Bayer  collaborative  agreement  related  to  costs  of  clinical  materials  sold,  which  were  approximately
$297,000  and  $213,000  for  fiscal  years  2013  and  2012,  respectively.  There  were  no  similar  costs  recorded
in fiscal year 2014.

Novartis

In October 2010, the Company entered  into  a three-year right-to-test agreement with Novartis
Institutes for BioMedical Research, Inc. (Novartis).  The agreement provides Novartis with  the right to
(a) test the Company’s ADC technology  with  individual antibodies provided by Novartis under a
right-to-test, or research, license, (b)  take exclusive options, with  certain restrictions,  to  individual
targets selected by Novartis for specified option  periods and (c) upon exercise of  those options, take
exclusive licenses to use the Company’s ADC technology to develop and commercialize products for a
specified number of individual targets on  terms  agreed upon  at the  inception of the right-to-test
agreement. The initial three-year term  of the right-to-test agreement was extended by Novartis in
October 2013 for an additional one-year period by payment of a $5 million fee  to  the Company. In
addition to the one-year extension taken in October 2013, the terms of the right-to-test agreement
allow Novartis to extend the research term for  one additional  one-year period by payment  of additional
consideration. The terms of the right-to-test  agreement require Novartis to exercise its options for the
development and commercialization licenses by the end  of  the term of the research license. The
Company received a $45 million upfront payment in  connection with the execution of the right-to-test
agreement, and for each development  and commercialization license for  a specific target, the Company
is entitled to receive an exercise fee  of  $1  million and up to a total  of  $199.5 million in milestone
payments, plus royalties on the commercial sales  of any  resulting products. The  total milestones are
categorized as follows: development milestones—$22.5  million; regulatory milestones—$77 million; and
sales milestones—$100 million. The Company also is entitled to receive payments for  research  and

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C. Agreements (Continued)

development activities performed on  behalf of Novartis. Novartis is responsible for the manufacturing,
product  development and marketing  of any products resulting from this agreement.

In March 2013, the Company and Novartis amended the  right-to-test agreement so that Novartis

can take a license to develop and commercialize products directed at two pre-defined and related
undisclosed targets, one target licensed  on an exclusive basis and  the other target initially licensed on a
non-exclusive basis. The target licensed  on a non-exclusive basis may be converted to an exclusive
target by notice and payment to the Company of an agreed-upon fee of at least  $5 million, depending
on specific circumstances. The Company received a $3.5  million fee in  connection with  the execution of
the amendment to the agreement. The Company  may be required to credit this fee  against future
milestone payments if Novartis discontinues  the development of a specified product under certain
circumstances.

In connection with the amendment, in March  2013, Novartis took the license referenced above

under the right-to-test agreement, as  amended,  enabling it to develop and commercialize products
directed at the two targets. The Company  received a  $1 million upfront fee  with the execution of  this
license. Additionally, the execution of this  license  provides the Company the opportunity to receive
milestone payments totaling $199.5 million (development milestones—$22.5 million; regulatory
milestones—$77 million; and sales milestones—$100  million) or $238  million (development
milestones—$22.5 million; regulatory  milestones—$115.5  million; and sales milestones—$100 million),
depending on the composition of any resulting products.

In October 2013 and November 2013, Novartis  took its second and third exclusive licenses to

single targets, each triggering  a $1 million  payment  to  the Company and the opportunity to receive
milestone payments totaling $199.5 million for  each license taken, as outlined above, plus royalties on
the commercial sales of any resulting products.  The next payment the Company could receive would
either be a $5 million development milestone for commencement of a Phase I clinical trial  under any
of these  three licenses, or a $1 million exercise fee for the  execution of a  fourth license. At the time of
execution of these agreements, there  was significant uncertainty as to whether these  milestones would
be achieved. In consideration of this,  as  well  as the Company’s  past  involvement in  the research and
manufacturing of these product candidates, these  milestones were  deemed substantive. Additionally, the
Company is entitled to receive royalties  on  product  sales,  if any. Novartis also  has the right  to  convert
the noted non-exclusive license to an  exclusive  license, in which case the Company would be entitled  to
receive, depending on the composition of  resultant products, an upward adjustment on milestone
payments.

In accordance with ACS 605-25 (as amended by ASU  No. 2009-13), the Company identified all of

the deliverables at the inception of the  right-to-test agreement and subsequently when amended. The
significant deliverables were determined to be the right-to-test, or research, license, the development
and commercialization licenses, rights  to  future technological improvements, and the research services.
The options to obtain development and commercialization licenses in the  right-to-test agreement were
determined not to be substantive and, as  a  result, the exclusive development and commercialization
licenses were considered deliverables  at the inception of the right-to-test agreement. Factors  that  were
considered in determining the options were  not substantive included (i) the overall objective of the
agreement was for Novartis to obtain development  and  commercialization licenses, (ii) the  size of the
exercise fee of $1 million for each development and commercialization license obtained is not

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significant relative to the $45 million  upfront  payment that was due at the  inception of the right-to-test
agreement, (iii) the limited economic  benefit that  Novartis could obtain  from the right-to-test
agreement unless it exercised its options  to  obtain development and commercialization licenses, and
(iv) the  lack of economic penalties as  a  result  of  exercising the options.

The Company has determined that the research license together with the development and

commercialization licenses represent  one  unit of accounting as the  research license does not have
stand-alone value from the development and commercialization licenses due to the lack of
transferability of the research license and the limited economic benefit Novartis would derive if they
did not obtain any development and commercialization licenses. The Company  has also determined
that this unit of accounting does have stand-alone value  from the  rights to future technological
improvements and the research services. The rights to future technological improvements and the
research services are considered separate units of accounting as each of these  was determined to have
stand-alone value. The rights to future technological improvements have  stand-alone value as Novartis
would be able to use those items for  their intended purpose without  the undelivered elements. The
research services have stand-alone value  as similar services are sold separately by other vendors.

The estimated selling prices for the development and commercialization licenses  are the
Company’s best estimate of selling price  and  were determined based on market conditions, similar
arrangements entered into by third parties, including  the Company’s understanding of pricing terms
offered by its competitors for single-target development and commercialization licenses that utilize
ADC technology, and entity-specific factors such as the  pricing terms of the Company’s previous single-
target development and commercialization licenses,  recent preclinical and clinical testing  results of
therapeutic products that use the Company’s ADC  technology, and the Company’s pricing practices and
pricing objectives. The estimated selling  price of the right to technological improvements is the
Company’s best estimate of selling price  and  was determined by  estimating the probability  that
technological improvements will be made and the probability that  such technological improvements
made will be used by Novartis. In estimating these probabilities, we considered factors such as the
technology that is the subject of the development and commercialization licenses, our history of making
technological improvements, and when  such improvements, if any, were  likely  to  occur relative to the
stage of development of any product candidates pursuant to the development and commercialization
licenses. The Company’s estimate of probability  considered the likely period of time that any
improvements would be utilized, which  was  estimated  to  be ten years following delivery of a
commercialization and development license. The  value of any  technological improvements made
available after this ten year period was considered to be de minimis due to the significant additional
costs that would be incurred to incorporate such technology into any existing  product candidates.  The
estimate of probability was multiplied  by  the estimated selling price of the development and
commercialization licenses and the resulting cash flow was discounted at a  rate of  16%, representing
the Company’s estimate of its cost of capital at the time. The estimated selling price of the  research
services was based on third-party evidence given the  nature of the  research  services to be performed
for Novartis and market rates for similar services.

Upon payment of the extension fee in October 2013, the  total  arrangement consideration  of
$60.2 million (which comprises the $45  million upfront payment, the amendment fee of $3.5  million,
the $5 million extension fee, the exercise fee  for each license, and the  expected fees for the research
services to be provided under the remainder of the  arrangement) was reallocated to the deliverables

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C. Agreements (Continued)

based on the relative selling price method  as follows: $55  million to the delivered and undelivered
development and commercialization licenses; $4.5 million to the rights to future technological
improvements; and $710,000 to the research services. The  Company recorded $17.2 million  of the
$55 million of the arrangement consideration outlined above for the two development  and
commercialization licenses taken by Novartis in October 2013  and November 2013, which is included in
license and milestone fee revenue for the year ended  June 30, 2014. The Company also recorded  a
cumulative catch-up of $1 million for the  license delivered in March 2013 and  the delivered portion of
the license covering future technological improvements, which is included  in license and milestone fee
revenue for the year ended June 30, 2014. Upon execution of the development and commercialization
license taken by Novartis in March 2013,  the  Company  recorded $11.1 million of the arrangement
consideration outlined above, which is  included in license and milestone fee revenue for the fiscal  year
ended June 30, 2013.

Since execution of the first development and  commercialization  license taken in March 2013, the

amount of the total arrangement consideration  allocated to future technological improvements  is being
recognized as revenue ratably over the period  the Company is  obligated to make available any
technological improvements, which is equivalent to the estimated term of the agreement. The  Company
estimates the term of a development and commercialization license to be  approximately 25 years, which
reflects management’s estimate of the  time  necessary  to  develop and commercialize products pursuant
to the license plus the estimated royalty  term. The Company reassesses the estimated term at the end
of each reporting period. The Company does  not control  when Novartis will exercise its options for
development and commercialization licenses. As  a result, the Company cannot predict when it will
recognize the related remaining license revenue except that it will be within the term of the research
license. The Company will recognize research services revenue as the related services  are delivered.

Costs directly attributable to the Novartis collaborative agreement  are comprised of compensation

and benefits related to employees who provided research and development services on behalf of
Novartis as well as costs of clinical materials sold. Indirect costs  are not identified to individual
collaborators. The costs related to the research and  development services  amounted  to  $1.4 million,
$2.4 million and $1.1 million for fiscal  years 2014, 2013 and 2012,  respectively. The  costs related to
clinical materials sold were approximately  $1.3 million, $134,000 and $14,000 for fiscal years 2014, 2013
and 2012, respectively.

Lilly

In December 2011, the Company entered into a three-year right-to-test  agreement with  Eli Lilly
and Company (Lilly). The agreement provides Lilly with the right to (a) take exclusive options,  with
certain restrictions, to individual targets selected by  Lilly for specified  option periods, (b) test the
Company’s maytansinoid ADC technology  with Lilly’s antibodies directed to the optioned targets under
a right-to-test, or research, license, and  (c) upon exercise  of  those options, take exclusive licenses to use
the Company’s maytansinoid ADC technology to develop and commercialize products for a specified
number of individual targets on terms  agreed upon at the inception  of  the right-to-test agreement. The
terms of the right-to-test agreement require Lilly to exercise its options for the development and
commercialization licenses by the end  of  the term of  the research license. In August 2013, Lilly took its
first exclusive license to a single target.

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C. Agreements (Continued)

The Company received a $20 million  upfront  payment in connection with the execution of the

right-to-test agreement, and for the first development  and  commercialization license taken in August
2013 and amended in December 2013, the Company received an exercise fee in the amount of
$2 million and is entitled to receive up  to  a total of $199 million in milestone payments, plus royalties
on the commercial sales of any resulting  products. Lilly has  the right to elect, at its discretion, which of
the two additional development and commercialization licenses it has  a right to take under the
right-to-test agreement will have no exercise fee and which will have an exercise fee of $2 million. With
respect to any subsequent development  and commercialization license taken, if Lilly elects that the
$2 million exercise fee is payable, the  Company is  entitled to receive, in addition to the exercise  fee, up
to a total of $199 million in milestone  payments, plus  royalties on  the commercial sales of any resulting
products. If Lilly elects that no exercise fee  is  payable when it takes a development and
commercialization license, the Company  is entitled to receive  up to a total of $200.5 million in
milestone payments, plus royalties on the  commercial sales of any resulting products. The total
milestones are categorized as follows:  development milestones—$29 million for the development and
commercialization licenses with respect to which the  $2  million exercise fee is paid,  and $30.5 million
for the development and commercialization license with respect  to  which no exercise fee is payable;
regulatory milestones—$70 million in  all  cases; and sales milestones—$100 million in all cases.  The
next payment the Company could receive  would either be a $5 million development milestone payment
with the initiation  of a Phase I clinical trial under the  first development and commercialization license
taken, or a $2 million exercise fee for the  execution of an additional license if  Lilly elects to pay the
exercise fee with respect to such license. At the time of execution of this agreement, there was
significant uncertainty as to whether  the  milestone related to initiation of  a Phase I clinical trial under
the first development and commercialization license  would be achieved. In consideration of this, as well
as the Company’s  expected involvement in the research  and manufacturing of  these product candidates,
this  milestone was deemed substantive. The Company also is entitled to receive payments for delivery
of cytotoxic agents to Lilly and research  and development  activities performed on behalf of Lilly.  Lilly
is responsible for the manufacturing,  product development and marketing of any  products resulting
from this collaboration.

In accordance with ASC 605-25 (as amended  by ASU No.  2009-13),  the Company identified  all  of

the deliverables at the inception of the  right-to-test agreement. The significant deliverables were
determined to be the right-to-test, or research, license,  the exclusive development and
commercialization licenses, rights to  future  technological  improvements, delivery of cytotoxic agents and
the research services. The options to  obtain development and commercialization  licenses in the
right-to-test agreement were determined not to be substantive and, as a result, the exclusive
development and commercialization licenses were considered deliverables at the inception of the
right-to-test agreement. Factors that  were considered  in determining the options were  not  substantive
included (i) the overall objective of the agreement was for  Lilly to obtain development and
commercialization licenses, (ii) the size  of  the  exercise fees of $2 million for each development and
commercialization license taken beyond the first  license is not significant relative to the $20 million
upfront payment that was due at the  inception  of  the right-to-test agreement, (iii) the  limited economic
benefit that Lilly could obtain from the right-to-test  agreement unless it exercised its options to obtain
development and commercialization licenses, and (iv)  the lack of economic penalties as a result  of
exercising the options.

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C. Agreements (Continued)

The Company has determined that the research license together with the development and

commercialization licenses represent  one  unit of accounting as the  research license does not have
stand-alone value from the development and commercialization licenses due to the lack of
transferability of the research license and the limited economic benefit Lilly would derive if they did
not obtain any development and commercialization  licenses. The Company has also determined  that
this  unit of accounting has stand-alone value  from the rights to future technological improvements, the
delivery of cytotoxic agents and the research  services. The rights to future technological improvements,
delivery of cytotoxic agents and the research  services are considered separate units of accounting as
each  of these was determined to have  stand-alone value. The rights  to  future technological
improvements have stand-alone value as Lilly would be able to use those  items for  their intended
purpose without the undelivered elements.  The research services  and cytotoxic agents  have stand-alone
value as similar services and products  are  sold  separately by other vendors.

The estimated selling prices for the development and commercialization licenses  are the
Company’s best estimate of selling price  and  were determined based on market conditions, similar
arrangements entered into by third parties, including  pricing terms offered by our competitors for
single-target development and commercialization licenses that utilize antibody-drug conjugate
technology, and entity-specific factors  such as the pricing  terms of the Company’s previous  single-target
development and commercialization licenses, recent preclinical and clinical testing results of therapeutic
products that use the Company’s ADC  technology,  and  the Company’s pricing practices and pricing
objectives. The estimated selling price of the rights to technological improvements is the  Company’s
best estimate of selling price and was determined by  estimating the probability that technological
improvements will be made, and the probability that technological  improvements made will be used by
Lilly. In estimating these probabilities, we considered factors such as the  technology that is  the subject
of the development and commercialization licenses, our  history of  making technological improvements,
and when such improvements, if any,  were likely  to  occur relative to the stage  of development of any
product  candidates pursuant to the development and  commercialization  licenses. The  Company’s
estimate of probability considered the  likely period of time that any improvements would be utilized,
which  was estimated to be ten years following delivery of a  commercialization and development license.
The value of any technological improvements  made available after this ten year  period was considered
to be de minimis due to the significant additional costs that would  be  incurred to incorporate such
technology into any existing product candidates.  The estimate of probability was multiplied by the
estimated selling price of the development and commercialization licenses and the resulting cash flow
was discounted at a rate of 16%, representing the  Company’s estimate of its cost  of capital at  the time.
The estimated selling price of the cytotoxic agent  was based on third-party evidence given market rates
for the manufacture of such cytotoxic agents. The estimated selling price of the research services was
based on third-party evidence given the nature of the research services to be performed for Lilly  and
market rates for similar services.

The total arrangement consideration  of $28.2 million (which comprises the $20 million upfront
payment, the exercise fee, if any, for  each license, the expected fees for the research services to be
provided and the cytotoxic agent to be  delivered under the arrangement) was  allocated to the
deliverables based on the relative selling price method as follows: $23.5  million  to  the development and
commercialization licenses; $0.6 million  to the rights to future technological improvements, $0.8 million
to the sale of cytotoxic agent; and $3.3  million to the research services. Upon execution of the

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AS OF JUNE 30, 2014

C. Agreements (Continued)

development and commercialization license taken by Lilly  in  August  2013, the Company recorded
$7.8 million of the $23.5 million of the arrangement  consideration outlined above, which is included in
license and milestone fee revenue for the year ended  June 30, 2014. With this first development and
commercialization license taken, the  amount of the total arrangement consideration allocated to future
technological improvements will commence  to  be  recognized as  revenue  ratably over the period the
Company is obligated to make available any technological improvements, which is the equivalent to the
estimated term of the license. The Company estimates  the term of a  development and
commercialization license to be approximately 25 years, which reflects  management’s estimate of the
time necessary to develop and commercialize  therapeutic products pursuant to the  license plus the
estimated royalty term. The Company  will reassess the estimated term at each  subsequent reporting
period. The Company will recognize as  license  revenue  an equal  amount  of the total remaining
$15.7 million of arrangement consideration allocated to the development and commercialization
licenses as each individual license is delivered to Lilly upon Lilly’s exercise of its remaining options to
such licenses. The Company does not  control  when Lilly  will exercise its options for development and
commercialization licenses. As a result,  the Company cannot predict when it will recognize the related
license revenue except that it will be within the term of the research license. The Company will
recognize research services revenue and  revenue from the delivery of cytotoxic  agents as the related
services and cytotoxic agents are delivered.

In December 2013, the Company and Lilly amended the right-to-test agreement and the first
development and commercialization license. Under these amendments, Lilly now  has the right  to
extend the three-year research period under the  right-to-test agreement for  up to two nine-month
periods by payment to the Company  of additional  consideration prior to the expiration of both the
original term or the first extended term  of that agreement. In addition, Lilly retroactively paid the
Company an exercise fee of $2 million for the  first development and commercialization license, and has
the right to elect, at its discretion, which  of the additional  development and commercialization licenses,
if any, taken under the right-to-test agreement will  have  no exercise fee and which  will have an exercise
fee of $2 million. The application of the  $2  million exercise fee to the first license granted under the
arrangement did not impact the total arrangement consideration, only the timing of payment of the
consideration. Due to the contingent nature of the extension  fees,  the lack of overall change in  the
total consideration for the licenses and the Company’s  conclusion that there has been no change in the
relative selling prices originally used  in the allocation of the consideration, there was no  accounting
impact upon the execution of the amendment.

Costs directly attributable to the Lilly collaborative agreement are comprised of compensation and

benefits related to employees who provided research and development  services  on behalf of  Lilly as
well as costs of clinical materials sold. Indirect costs are not identified  to  individual collaborators. The
costs related to the research and development services amounted to approximately $1.2 million,
$310,000 and $94,000 for fiscal years  2014, 2013 and 2012  respectively. The costs  related to clinical
materials  sold  were  approximately  $26,000  and  $10,000  for  fiscal  years  2014  and  2013,  respectively.
There were no similar costs recorded in  fiscal  year 2012.

CytomX

In January 2014, the Company entered into a reciprocal  right-to-test agreement with CytomX

Therapeutics, Inc. (CytomX). The agreement provides CytomX with  the right to test the Company’s

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AS OF JUNE 30, 2014

C. Agreements (Continued)
ADC technology with CytomX Probodies(cid:5) to create Probody-drug conjugates (PDCs) directed  to  a
specified number of targets under a right-to-test,  or research, license, and to subsequently  take an
exclusive, worldwide license to use the Company’s ADC technology to develop  and commercialize
PDCs directed to the specified targets  on terms  agreed upon at the inception of the right-to-test
agreement. The Company received no  upfront cash  payment  in connection  with the execution of  the
right-to-test agreement. Instead, the Company received reciprocal rights to CytomX’s  Probody
technology whereby the Company was provided the right to test CytomX’s Probody technology to
create PDCs directed to a specified number of targets and to subsequently take exclusive, worldwide
licenses to develop and commercialize  PDCs directed  to  the specified  targets on  terms agreed  upon at
the inception of the right-to-test agreement.  The  terms of the right-to-test agreement require  the
Company and CytomX to each take its  respective development and commercialization licenses by the
end of the term of the research licenses. In  addition,  both the Company  and  CytomX are  required to
perform specific research activities under  the right-to-test agreement on  behalf of the other party  for
no monetary consideration.

With respect to the development and  commercialization license that may be taken by CytomX, the
Company is entitled to receive up to  a total of $160  million in milestone  payments plus royalties on the
commercial sales of any resulting product.  The total milestones are categorized as  follows: development
milestones—$10 million; regulatory milestones—$50 million; and sales milestones—$100 million.
Assuming no annual maintenance fee is  payable  as described below, the next  payment the  Company
could receive would be a $1 million development  milestone  payment with  commencement of  a Phase I
clinical trial. At the time of execution of the right-to-test agreement,  there was significant uncertainty as
to whether the milestone related to the  Phase I  clinical  trial would be achieved. In consideration of
this, as well as the Company’s expected  involvement in the research and manufacturing of any  product
candidate, this milestone was deemed  substantive. CytomX is  responsible  for the  manufacturing,
product  development and marketing  of any PDC  resulting from  the development  and
commercialization license taken by CytomX under this collaboration.

With respect to any development and commercialization license that may be taken  by  the
Company, the Company will potentially be required to pay up to a total of $80  million in milestone
payments per license, plus royalties on  the commercial  sales  of any  resulting product. The total
milestones per license are categorized as  follows:  development milestones—$7 million; regulatory
milestones—$23 million; and sales milestones—$50 million. Assuming no  annual maintenance  fee  is
payable as described below, the next payment  the Company  could be required  to  make is a $1  million
development milestone payment with commencement  of  a Phase I clinical trial. The Company  is
responsible for the manufacturing, product  development and marketing of any PDC resulting  from any
development and commercialization license taken by the  Company under this collaboration.

In addition, each party may be liable to pay annual maintenance fees to the other  party if  the

licensed PDC product candidate covered  under each  development and commercialization  license has
not progressed to a specified stage of development  within  a specified time frame.

The arrangement was accounted for  based  on the fair value  of  the items  exchanged. The items to

be delivered to CytomX under the arrangement are accounted for under the Company’s  revenue
recognition policy. The items to be received from CytomX are recorded  as research and development
expenses as incurred.

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AS OF JUNE 30, 2014

C. Agreements (Continued)

In accordance with ASC 605-25 (as amended  by ASU No.  2009-13),  the Company identified  all  of

the deliverables at the inception of the  right-to-test agreement. The significant deliverables were
determined to be the right-to-test, or research, license,  the exclusive development and
commercialization license, rights to future technological improvements, and the research services. The
research license in the right-to-test agreement was  determined not to be substantive and, as a result,
the exclusive development and commercialization license was considered a deliverable at the inception
of the right-to-test agreement. Factors  that were  considered in determining the research license was not
substantive included (i) the overall objective of  the agreement is for CytomX to obtain a development
and commercialization license, (ii) there  are  no exercise  fees payable  upon taking  the development and
commercialization license, (iii) the limited  economic benefit  that CytomX could obtain from  the
right-to-test agreement unless CytomX was  able to take the development and commercialization
license, and (iv) the lack of economic penalties as a result of taking  the license.

The Company has determined that the research license from the  Company to CytomX together
with the development and commercialization  license from  the Company to CytomX represent one  unit
of accounting as the research license  does not have stand-alone value from the development and
commercialization license due to the  lack of  transferability of  the research license and the limited
economic benefit CytomX would derive if  they  did  not obtain  any development and  commercialization
license. The Company has also determined that  this unit of accounting has stand-alone value  from the
rights to future technological improvements and  the research services. The rights  to  future
technological improvements and the  research  services are considered separate units of accounting as
each  of these was determined to have  stand-alone value. The rights  to  future technological
improvements have stand-alone value as CytomX would be able to use those items for their  intended
purpose without the undelivered elements.  The research services  have stand-alone value as  similar
services are sold separately by other  vendors.

The estimated selling price for the development and  commercialization  license is the Company’s

best estimate of selling price and was determined based on market conditions, similar arrangements
entered into by third parties, including  pricing terms offered by the Company’s competitors for single-
target development and commercialization licenses  that utilize antibody-drug conjugate technology,  and
entity-specific factors such as the pricing  terms of the Company’s previous single-target development
and commercialization licenses, recent preclinical and clinical testing results of therapeutic products
that use the Company’s ADC technology, and the Company’s pricing practices and pricing objectives.
In order to determine the best estimate  of selling price, the Company determined the overall value of a
license by calculating a risk-adjusted  net present value of a  recent, comparable transaction the
Company entered  into with another collaborator. This overall value was then decreased by
risk-adjusting the net present value of the contingent  consideration (the milestones and royalties)
payable by CytomX under the development and commercialization license.  This amount represents  the
value that a third party would be willing to pay  as an upfront payment for this license to the
Company’s technology.

The estimated selling price of the rights to technological  improvements  is the Company’s best

estimate of selling price and was determined by estimating  the probability that technological
improvements will be made, and the probability that technological  improvements made will be used by
CytomX. In estimating these probabilities,  the Company considered factors  such as the technology that
is the subject of the development and commercialization license, the Company’s history  of making

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C. Agreements (Continued)

technological improvements, and when  such improvements, if any, were  likely  to  occur relative to the
stage of development of the product candidate pursuant  to the development and commercialization
license. The Company’s estimate of probability  considered the likely period of time that any
improvements would be utilized, which  was  estimated  to  be ten years following delivery of the
commercialization and development license. The  value of any  technological improvements made
available after this ten year period was considered to be de minimis due to the significant additional
costs that would be incurred to incorporate such technology into any existing  product candidate.  The
estimate of probability was multiplied  by  the estimated selling price of the development and
commercialization license and the resulting cash flow was discounted at a  rate of  13%, representing the
Company’s estimate of its cost of capital at  the time.

The estimated selling price of the research  services  was based on third-party evidence  given the

nature of the research services to be performed for  CytomX and market rates for  similar services.

The total allocable consideration of $13.1 million (which comprises the  $13.0 million that a third
party would be willing to pay as an upfront payment for this license  to  the  Company’s technology plus
$140,000 for the fair value of fees for  the research services to be provided)  was  allocated  to  the
deliverables based on the relative selling price method as follows: $12.7  million  to  the development and
commercialization license; $350,000 to the rights  to  future technological improvements and $140,000 to
the research services. The Company will  recognize as license revenue the amount of the  total  allocable
consideration allocated to the development and commercialization  license when the development  and
commercialization license is delivered  to  CytomX.  At  the time the license is taken,  the amount of the
total allocable consideration allocated  to  future  technological improvements  will  commence to be
recognized as revenue ratably over the period  the Company is  obligated  to  make available any
technological improvements, which is the equivalent  to  the estimated term of the  license. The  Company
estimates the term of a development and commercialization license to be  approximately  25 years, which
reflects management’s estimate of the  time necessary to develop and commercialize therapeutic
products pursuant to the license plus the  estimated royalty term. The Company will be required to
reassess the estimated term at each subsequent reporting period.  The Company  does not control when
CytomX will take the development and  commercialization  license.  As a result, the Company  cannot
predict when it will recognize the related  license revenue except that  it will  be  within the term  of the
research license. The Company will recognize research services revenue as  the related services  are
delivered.

No license fee revenue has been recognized  related to this agreement through  June 30, 2014 as  the

research license was not considered to be substantive  and the  development and  commercialization
license had not been delivered at this  time.  Accordingly, $13.0 million of allocated arrangement
consideration is included in long-term  deferred revenue at June 30, 2014.

The $13.1 million of total allocable consideration  to  be  accounted for  as revenue described  above

is also the amount that was used to account  for the  expense of the  licenses and research services the
Company received or will receive from CytomX. Based  on an  estimate of the  research  services  that
CytomX will be providing to the Company  for no monetary consideration, $310,000 was allocated to
such services and will be expensed over  the  period the  services  are provided. The balance of
$12.8 million pertains to technology rights received and these amounts have been charged to research
and development expense during the year  ended June  30, 2014 upon execution of the  research
agreement.

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C. Agreements (Continued)

Other Collaborative Agreements

In December 2004, the Company entered into a development and license agreement with  a

predecessor to Janssen Biotech (formerly  known as Centocor), a wholly owned subsidiary of Johnson &
Johnson. Under the terms of this agreement, Janssen was granted exclusive worldwide rights  to  develop
and commercialize anticancer therapeutics that consist of the  Company’s maytansinoid cell-killing  agent
attached to an (cid:1)v integrin-targeting antibody that was developed  by Janssen. Under the  terms of the
agreement, the Company received an upfront payment  of $1 million upon execution of the agreement.

In December 2007, the Company licensed from Janssen the exclusive, worldwide  right to develop

and commercialize an ADC compound,  IMGN388,  that consists of an (cid:1)v  integrin-targeting antibody
developed by them and one of the Company’s  maytansinoid cell-killing  agents. This  license reallocated
the parties’ respective responsibilities  and financial  obligations from  the license  referenced  above. In
November 2011, the Company announced  its decision to discontinue  development of IMGN388. During
the first quarter of fiscal 2013, the 2007 license agreement was terminated with rights to the  product
candidate reverting back to Janssen. Per  notice to the Company, effective July 2014,  Janssen
relinquished its rights to the product  candidate. Accordingly, the remaining $241,000 of  the $1 million
upfront fee received from Janssen upon execution of the 2004 license agreement is included  in
short-term deferred revenue at June  30, 2014.

D. Cash and Cash Equivalents

As of June 30, 2014 and June 30, 2013, the Company  held $142.3  million  and $195.0 million,

respectively, in cash and money market funds consisting principally  of  U.S. Government-issued
securities and high quality, short-term commercial paper  which  were  classified as cash and  cash
equivalents.

E. Property and Equipment

Property and equipment consisted of  the following at June 30, 2014 and 2013 (in thousands):

June 30,

2014

2013

Leasehold improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Machinery and equipment . . . . . . . . . . . . . . . . . . . . . . . . . . .
Computer hardware and software . . . . . . . . . . . . . . . . . . . . . .
Furniture and fixtures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Assets under construction . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 28,464
16,724
5,846
1,876
3,688

$ 26,777
14,741
4,894
1,540
814

Less accumulated depreciation . . . . . . . . . . . . . . . . . . . . . . . .

$ 56,598
(42,249)

$ 48,766
(37,983)

Property and equipment, net

. . . . . . . . . . . . . . . . . . . . . . . . .

$ 14,349

$ 10,783

Depreciation expense was approximately $4.6  million  for each of  the  years  ended June 30, 2014,

2013 and 2012. Included in the table  above, the  Company’s  investment in equipment  under capital
leases was $574,000, net of accumulated  amortization  of  $50,000, at June 30,  2014 and  $110,000, net of
accumulated amortization of $22,000, at  June 30, 2013.

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F.

Income Taxes

The difference between the Company’s expected tax benefit, as computed by applying the U.S.

federal corporate tax rate of 34% to loss  before the benefit  for income taxes, and actual tax is
reconciled in the following chart (in thousands):

Year Ended June 30,

2014

2013

2012

Loss before income tax expense . . . . . . . . . . . . . . .

$(71,364) $(72,811) $(73,319)

Expected tax benefit at 34% . . . . . . . . . . . . . . . . . .
Permanent differences . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . .
State tax benefit net of federal benefit
Increase in valuation allowance, net . . . . . . . . . . . .
Federal research credit . . . . . . . . . . . . . . . . . . . . . .
Expired loss and credit carryforwards . . . . . . . . . . .

$(24,264) $(24,756) $(24,928)
1,470
1,540
(4,204)
(3,921)
25,274
25,624
(603)
(2,260)
2,991
3,773

1,953
(4,062)
26,011
(1,002)
1,364

Benefit for income taxes . . . . . . . . . . . . . . . . . . . .

$

— $

— $

—

At June  30, 2014, the Company has net operating loss  carryforwards of approximately

$388.8 million available to reduce federal  taxable income, if any, that expire in 2019  through 2034 and
$227.9 million available to reduce state taxable  income, if  any,  that expire  in fiscal 2019 through  fiscal
2034. Included in the federal and state  carryforwards is $24.6 million  and $21.2 million,  respectively,
related to deductions from the exercise  of  stock options and  the  related  tax benefit  will result in an
increase in additional paid-in capital if  and  when realized through a  reduction of taxes paid  in cash.
The Company also has federal and state research tax  credits of approximately $16.8 million available to
offset federal and state income taxes, which expire  beginning in  fiscal 2015. Due to the degree of
uncertainty related to the ultimate use of  the loss carryforwards  and tax credits, the Company  has
established a  valuation allowance to fully reserve these tax benefits.

Deferred income taxes reflect the net  tax  effects of temporary  differences between the  carrying
amounts of assets and liabilities for financial  reporting purposes and the amounts used for income tax

100

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

F.

Income Taxes (Continued)

purposes. Significant components of the Company’s deferred tax assets as  of June  30, 2014 and 2013
are as follows (in thousands):

June 30,

2014

2013

Net operating loss carryforwards . . . . . . . . . . . . . . . . . . . . .
Research and development tax credit carryforwards . . . . . . .
Property and other intangible assets . . . . . . . . . . . . . . . . . . .
Deferred revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . .
Deferred lease incentive . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 144,230
14,453
2,386
24,095
9,047
3,908
1,234

$ 121,937
12,806
2,077
25,484
6,534
3,996
508

Total deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valuation allowance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 199,353
(199,353)

$ 173,342
(173,342)

Net deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$

— $

—

The valuation allowance increased by $26.0  million  during  2014 due primarily to the additional  net

loss recognized during the year, partially offset by the expiration of net  operating loss carryforwards.

Utilization of the NOL and R&D credit carryforwards may  be  subject to a substantial annual
limitation due to ownership change limitations that  have occurred previously or that could occur in the
future as provided by Section 382 of  the  Internal Revenue Code of 1986,  as well as  similar state  and
foreign provisions. These ownership changes may limit the  amount  of  NOL and R&D  credit carry
forwards that can be utilized annually  to  offset  future taxable  income and tax, respectively. In general,
an ownership change, as defined by Section 382, results from transactions  increasing  the ownership of
certain shareholders or public groups in  the stock  of  a corporation  by more than 50 percentage points
over a three-year period. Since the Company’s formation, it has raised capital through  the issuance of
capital stock on several occasions (both pre and post initial public  offering) which,  combined with the
purchasing shareholders’ subsequent  disposition of those shares, may  have resulted  in a change of
control, as defined by Section 382, or could result  in a change  of control in the  future upon subsequent
disposition. The Company has not currently completed  a study to assess  whether  a change of control
has occurred or whether there have been multiple changes of control since its  formation due to the
significant complexity, costs associated  with such  study and the possibility that there could be additional
changes in control in the future. If the Company has  experienced a change  of control at  any time since
its  formation, utilization of its NOL or R&D  credit carry  forwards  would be subject to an  annual
limitation under Section 382 which is  determined by first multiplying the  value of  the Company’s stock
at the time of the ownership change  by  the applicable long-term  tax-exempt  rate, and then could be
subject to additional adjustments, as  required. Any limitation  may result in  expiration of a  portion of
the NOL or R&D credit carry forwards  before utilization.  Further, until a study  is completed and  any
limitation known, no amounts are being presented  as an uncertain tax position. The Company  does not
expect to have any taxable income for  at  least the  next several  years.

Interest and penalties related to the settlement of uncertain tax positions, if any,  will  be  reflected

in income tax expense. The Company  did  not recognize  any interest and penalties associated with

101

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

F.

Income Taxes (Continued)

unrecognized tax benefits in the accompanying consolidated  financial  statements. The Company  does
not expect any material changes to the unrecognized  benefits within 12 months of the reporting date.
Due to existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits
will not impact our effective tax rate. The  Company’s  loss  carryforwards are subject to adjustment by
state and federal taxing authorities, commencing  when those losses are  utilized to reduce taxable
income.

G. Capital Stock

Sale of Common Stock

On May 19, 2011, the Company filed  a Registration Statement on Form S- 3 with the Securities
and Exchange Commission. Pursuant  to  the  shelf  registration statement, in July 2012, the Company
issued and sold a total of 6,250,000 shares  of its  common stock at $16.00 per share through a public
offering resulting in gross proceeds of $100 million.

Common Stock Reserved

At June  30, 2014, the Company has reserved 11.39  million  shares of authorized common stock for

the future issuance of shares under the 2006 Plan and the 2004 Director Plan. See  ‘‘Stock-Based
Compensation’’ in Note B for a description of the 2006 Plan and the Former Plan and Note  G below
for a description of the 2004 Director Plan.

Stock Options

As of June 30, 2014, the 2006 Plan was the  only employee share-based compensation plan of  the

Company. During the year ended June 30, 2014, holders of options issued under the 2006  Plan and the
Former Plan exercised their rights to acquire an  aggregate of 1.1 million shares of common stock at
prices ranging from $3.19 to $15.83 per  share. The total proceeds to the Company from these  option
exercises were approximately $9.1 million.

The Company granted options with an exercise price equal to the fair  market  value of the common

stock on the date of such grant. The  following  options  and their respective weighted- average exercise
prices per share were exercisable at June  30, 2014, 2013 and 2012:

Exercisable
(in thousands)

Weighted-
Average
Exercise Price

June 30, 2014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
June 30, 2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
June 30, 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4,637
4,202
3,416

$9.79
$7.97
$6.34

2001 Non-Employee Director Stock Plan

In November 2001, the Company’s shareholders approved the  establishment of the  2001

Non-Employee Director Stock Plan,  or the 2001  Director Plan, and  50,000 shares of common stock to
be reserved for grant thereunder. The 2001 Director Plan provided for  the  granting of awards to

102

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

G. Capital Stock (Continued)

Non-Employee Directors and, at the election of Non-Employee Directors, to have all or a portion of
their awards in the form of cash, stock,  or stock  units. All  stock or  stock units are  immediately vested.
The number of stock or stock units issued was determined by the market value of  the Company’s
common stock on the last date of the  Company’s fiscal quarter for which the services are  rendered.
The 2001 Director Plan was administered  by the Board  of  Directors which was authorized to interpret
the provisions of the 2001 Director Plan,  determine  which  Non-Employee  Directors would be granted
awards, and determine the number of  shares of stock  for which a stock right will be granted. The 2001
Director Plan was replaced in 2004 by  the 2004  Non-Employee  Director Compensation and Deferred
Share Unit Plan.

During  the years ended June  30, 2014, 2013 and 2012, the  Company recorded approximately
$(30,000), $(1,000), and $29,000 in (expense reduction) compensation expense, respectively, related to
approximately 6,000 stock units outstanding  under  the 2001 Director  Plan. The value  of the stock units
is adjusted to market value at each reporting period.  No  stock units  have been issued under  the 2001
Plan subsequent to June 30, 2004. Pursuant to the 2001 Plan, in November 2011, the Company paid a
retiring director approximately $115,000  to  settle outstanding  stock units.

2004 Non-Employee Director Compensation  and Deferred Share  Unit Plan

In June 2004, the Board of Directors approved  the establishment of the 2004 Non-Employee
Director Compensation and Deferred Share Unit Plan, or the 2004 Director  Plan. The  2004 Director
Plan provided for the compensation  of  Non-Employee  Directors, awarding their annual retainers in the
form of deferred share units, and, at their  discretion, to have  all or a portion  of their  other
compensation such as meeting fees in the  form of  cash or deferred share units. The deferred  share
units for annual retainers vested one-twelfth  monthly over  the next year  after the award; other deferred
share units vested immediately upon issuance. The  number of deferred share units issued was
determined by the market value of the Company’s common stock on the last  date of the  Company’s
fiscal year prior to the fiscal year for  which services were rendered. The deferred share  units were to be
paid out in cash to each non-employee director based upon the market value of the  Company’s
common stock on the date of such director’s retirement  from the Board  of Directors of  the Company.
The 2004 Director Plan was administered  by the Board  of  Directors.

The 2004 Director Plan was amended on  September 5, 2006. Under the terms of the amended

2004 Director Plan, the redemption amount of deferred  share units will  be  paid in shares of common
stock of the Company under the 2006  Plan  in lieu of cash. As a  result of the change  in payout
structure, the value of the vested awards was  transferred to  additional paid-in capital  as of the
modification date and the total value of  the awards,  as calculated on the modification date,  was
expensed over the remainder of the vesting period. Accordingly,  the value of the share units is fixed
and will no longer be adjusted to market value  at each reporting period. In addition, the amended 2004
Director Plan changed the vesting for annual retainers to take  place quarterly over the three years after
the award and the number of deferred  share units awarded  for all compensation is now  based on the
market value of the Company’s common  stock on the  date of the award.

103

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

G. Capital Stock (Continued)

Compensation Policy for Non-Employee Directors

On September 16,  2009, the Board adopted a  new Compensation Policy for Non-Employee
Directors, which superseded the 2004 Plan  and made certain changes to the compensation of  its
non-employee directors. The policy was  amended  on November  11, 2009 to provide that, whenever the
Board has a non-employee Chairman  in lieu of a Lead Director,  the cash payment for the
non-employee Chairman of the Board shall be the same as the cash compensation that would otherwise
have been payable to the Lead Director.  Effective November 12,  2009, non-employee directors became
entitled to receive annual meeting fees  and committee fees under  the new policy. The new policy made
changes to the equity portion of the  non-employee director compensation, but left  the cash  portion
unchanged. Effective November 11, 2009,  non-employee directors became entitled to receive deferred
stock units under the new policy as follows:

(cid:127) New non-employee directors will be initially awarded a number of deferred stock units having  an
aggregate market value of $65,000, based on the closing price of our common stock on the date
of their initial election to the Board. These  awards  will vest quarterly over three years from  the
date  of grant, contingent upon the individual remaining a director of ImmunoGen as of each
vesting date.

(cid:127) On the first anniversary of a non-employee director’s initial  election to the Board, such

non-employee director will be awarded a number  of deferred stock  units  having an aggregate
market value of $30,000, based on the closing price  of our common stock on  such date of grant
and pro-rated based on the number of whole  months remaining between the first day of the
month in which such grant date occurs and  the first October 31 following the grant date. These
awards will generally vest quarterly over  approximately the period from the grant date  to  the
first November 1 following the grant  date, contingent upon the individual remaining a director
of ImmunoGen as of each vesting date.

(cid:127) Thereafter, non-employee directors  in general will  be  annually awarded a  number of deferred
stock units having an aggregate market value of $30,000, based on the closing price of our
common stock on the date of our annual meeting of shareholders. These  awards will vest
quarterly over approximately one year from the date of grant, contingent upon the individual
remaining a director of ImmunoGen  as of each vesting  date.

As with the 2004 Plan, vested deferred stock units are redeemed on the date a director  ceases to
be a member of the Board, at which time  such director’s deferred  stock units will be settled in shares
of our common stock issued under our  2006 Plan at a rate of one share for each vested deferred stock
unit then held. Any deferred stock units that remain unvested at that time will  be  forfeited. The new
policy provides that all unvested deferred  stock units will automatically vest immediately prior to the
occurrence of a change of control, as defined in the 2006 Plan. Pursuant to the Compensation Policy
for Non-Employee Directors, the Company issued two retiring directors an aggregate 46,298 shares of
common stock of the Company to settle outstanding  deferred share units in November 2011,  and
43,615 shares of common stock to a retiring director in November 2013.

104

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

G. Capital Stock (Continued)

In connection with the adoption of the new  compensation policy, the Board also amended the

2004 Plan as follows:

(cid:127) All unvested deferred stock awards  (other than any unvested initial  awards) were vested in full

on September 16, 2009 unless the date such deferred stock units were credited to the
non-employee director was less than  one  year prior  to  September 16, 2009, in which case such
unvested deferred stock units will vest  on the first  anniversary of the date such deferred  stock
units were credited to the non-employee director.

(cid:127) All unvested deferred stock awards  will automatically vest immediately  prior to the  occurrence

of a change of control.

On September 22,  2010, the Board revised the Compensation Policy for Non-Employee Directors

to provide that, in addition to the compensation  they received previously, they would also  become
entitled to receive stock option awards  having  a grant date fair value of  $30,000, determined using the
Black- Scholes option pricing model measured  on the date of grant,  which would  be  the date of  the
annual meeting of  shareholders.

On November 12, 2013, the Board amended the  Compensation Policy for Non-Employee Directors

to make certain changes to the compensation of its non-employee  directors,  including an  increase in
the fees paid  in cash to the non-employee  directors. Under  the terms of the amended policy, the
redemption amount of deferred share  units issued  will continue to be paid in shares of common stock
of the Company on the date a director ceases to be a  member of the Board. Annual retainers vest
quarterly over approximately one year from the date of grant, contingent upon the individual  remaining
a director of ImmunoGen as of each vesting date. The number of deferred share  units awarded is  now
fixed per the plan on the date of the award and is  no  longer based on the  market price of the
Company’s common stock on the date  of the  award. All unvested deferred stock awards will
automatically vest immediately prior  to  the occurrence  of  a change of control.

In addition to the deferred share units,  the Non-Employee Directors are now also entitled to
receive a fixed number of stock options instead of a fixed grant date  fair value of options, determined
using the Black-Scholes option pricing model measured on the date of grant, which would be the date
of the annual meeting of shareholders. These options vest quarterly over approximately  one year  from
the date of grant. Any new directors will  receive a pro-rated award, depending  on their date of election
to the Board. The directors received a  total of  80,000, 41,805 and 33,187 options in fiscal years ended
2014, 2013 and 2012, respectively, and  the related compensation expense is included in the amounts
discussed in the ‘‘Stock-Based Compensation’’ section of footnote  B above.

Pursuant to the Compensation Policy  for Non-Employee  Directors, as  amended, the  Company

recorded  approximately:

(cid:127) $433,000 in compensation expense during the year ended  June 30, 2014 related to the grant of

28,000 deferred share units and 19,000 deferred  share  units previously granted;

(cid:127) $351,000 in compensation expense during the year ended  June 30, 2013 related to the grant of

26,000 deferred share units and 21,000 deferred  share  units previously granted; and

(cid:127) $314,000 in compensation expense during the year ended  June 30, 2012 related to the grant of

33,000 deferred share units and 19,000 deferred  share  units previously granted.

105

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

H. Commitments and Contingencies

Leases

Effective July 27, 2007, the Company  entered into a  lease agreement with Intercontinental

Fund III for the rental of approximately 89,000 square feet of laboratory and office space at 830 Winter
Street, Waltham, MA through March  2020. The Company uses this space for its corporate headquarters
and other operations. In December 2013,  the Company modified its lease agreement  at 830  Winter
Street, Waltham, MA to include approximately 19,000 square  feet of additional office space through
2020, concurrent with the remainder  of the original lease term. As part of the lease amendment, the
Company will receive a construction  allowance of approximately $746,000 to build out office space to
the Company’s specifications. The Company obtained physical  control of the additional space to begin
construction in January 2014. In April,  2014, the  Company again modified its lease agreement at this
site to extend the lease to 2026. The Company may extend the lease for two  additional terms of five
years. As part of this lease amendment, the  Company will  receive a  construction  allowance of
approximately $1.1 million to build out  office space to the Company’s specifications. The Company  is
required to pay certain operating expenses  for the leased premises subject to escalation charges for
certain expense increases over a base amount.  The Company entered  into  a sublease in December 2009
for 14,100 square feet of this space in  Waltham through January 2015, with the sublessee having a
conditional option to extend the term for an  additional two years. However, the Company has notified
the sublessee that it does not intend  to  allow them to extend the term beyond January 2015.

Effective April 2012, the Company entered into a sublease agreement for the rental of 7,310

square  feet of laboratory and office space  at 830 Winter Street, Waltham, MA from Histogenics
Corporation. The term of the sublease  is for three  years  and the Company is required to pay certain
operating expenses for the leased premises  subject  to  escalation charges for certain  expense increases
over a base amount.

The Company also leases manufacturing and office space  at 333 Providence Highway, Norwood,
MA under an agreement through 2018  with  an  option to extend the lease  for an  additional term  of five
years. The Company is required to pay  certain  operating  expenses for the leased premises subject to
escalation charges for certain expense increases over a base amount.

Effective April 2013, the Company entered into a lease agreement with River Ridge Limited

Partnership for the rental of 7,507 square  feet  of  additional  office space at 100 River Ridge Drive,
Norwood, MA. The initial term of the lease is for  five  years and two months  commencing in July  2013
with an option for the Company to extend the  lease for an additional  term of five years. The Company
is required to pay certain operating expenses for the  leased premises subject to escalation charges for
certain expense increases over a base amount.

Facilities rent expense, net of sublease income, was approximately $5.4 million, $4.8 million and

$4.8 million during fiscal years 2014,  2013 and 2012, respectively.

106

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

H. Commitments and Contingencies (Continued)

As of June 30, 2014, the minimum rental commitments,  including real estate taxes and  other

expenses, for the next five fiscal years  and thereafter under the non-cancelable operating  lease
agreements discussed above are as follows  (in thousands):

2015 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2016 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2017 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thereafter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 7,150
6,924
6,941
7,046
6,235
43,887

Total minimum lease payments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total minimum rental income from subleases . . . . . . . . . . . . . . . . . . . . . .

$78,183
(408)

Total minimum lease payments, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$77,775

There are no obligations under capital leases as  of  June  30, 2014, as all of the  capital leases were

single payment obligations which have all been made.

Collaborations

The Company is contractually obligated  to  make potential future  success-based regulatory
milestone payments in conjunction with certain collaborative agreements. These payments are
contingent upon the occurrence of certain future  events and, given  the nature of these events,  it is
unclear when, if ever, the Company may be required to pay such  amounts.  Further, the timing  of  any
future payment is not reasonably estimable. During the  first quarter of fiscal  2013, the Company’s
license agreement with Janssen Biotech was terminated and, accordingly,  the Company  is no  longer
obligated to make $41.0 million of potential future success-based milestone  and third-party payments
under such agreement. As of June 30, 2014, the maximum amount that may be payable in the  future
under the Company’s current collaborative agreements is $162 million, $1.4 million of which  is
reimbursable by a third party under a separate agreement.

Litigation

The Company is not party to any material  litigation.

I. Employee Benefit Plans

The Company has a deferred compensation plan under Section 401(k) of the Internal Revenue
Code (the 401(k) Plan). Under the 401(k)  Plan,  eligible employees are permitted to contribute, subject
to certain limitations, up to 100% of their  gross  salary and the  Company’s matching  contribution is
50% of the first 6% of the eligible employees’  contributions. In  fiscal years  2014, 2013 and 2012,  the
Company’s contributions to the 401(k)  Plan totaled approximately  $710,000, $593,000, and $548,000,
respectively.

107

IMMUNOGEN, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)

AS OF JUNE 30, 2014

J. Quarterly Financial Information  (Unaudited)

Fiscal Year 2014

First Quarter
Ended

Second Quarter
Ended

Third Quarter
Ended

September 30, 2013 December 31, 2013 March 31, 2014

Fourth Quarter
Ended
June 30, 2014

(In thousands, except per share data)

Revenues:

License and milestone fees . . . . . . . . .
Royalty revenue . . . . . . . . . . . . . . . .
Research and development support . . .
Clinical materials revenue . . . . . . . . .

Total revenues . . . . . . . . . . . . . . . .

Expenses:

Research and development . . . . . . . . .
General and administrative . . . . . . . .

Total expenses . . . . . . . . . . . . . . . .

Loss from operations . . . . . . . . . . . . . .
. . . . . . .

Other income (expense), net

$ 13,167
2,053
1,990
8

17,218

22,029
6,526

28,555

(11,337)
111

$25,678
2,335
1,922
125

30,060

20,862
5,447

26,309

3,751
62

$

305
2,558
1,948
2,064

6,875

38,280
6,040

44,320

(37,445)
(7)

$

305
3,400
1,327
711

5,743

25,787
6,456

32,243

(26,500)
1

Net (loss) income . . . . . . . . . . . . . . . . .

$(11,226)

$ 3,813

$(37,452)

$(26,499)

Basic and diluted net (loss) income

per  common share . . . . . . . . . . . . .

$

(0.13)

$ 0.04

$

(0.44)

$

(0.31)

Fiscal Year 2013

First Quarter
Ended

Second Quarter
Ended

Third Quarter
Ended

September 30, 2012 December 31, 2012 March 31, 2013

Fourth Quarter
Ended
June 30, 2013

(In thousands, except per share data)

Revenues:

License and milestone fees . . . . . . . . .
Royalty revenue . . . . . . . . . . . . . . . .
Research and development support . . .
Clinical materials revenue . . . . . . . . .

Total revenues . . . . . . . . . . . . . . . .

Expenses:

Research and development . . . . . . . . .
General and administrative . . . . . . . .

Total expenses . . . . . . . . . . . . . . . .

Loss from operations . . . . . . . . . . . . . .
. . . . . . .

Other income (expense), net

$

933
—
1,377
1,781

4,091

23,700
5,639

29,339

(25,248)
56

$

429
—
2,036
147

2,612

21,656
5,464

27,120

(24,508)
115

$22,010
—
2,257
734

25,001

21,318
4,995

26,313

(1,312)
(39)

$

855
592
2,203
181

3,831

20,399
5,373

25,772

(21,941)
66

Net loss . . . . . . . . . . . . . . . . . . . . . . . .

$(25,192)

$(24,393)

$ (1,351)

$(21,875)

Basic and diluted net loss per

common share . . . . . . . . . . . . . . . .

$

(0.30)

$

(0.29)

$ (0.02)

$

(0.26)

108

Item 9. Changes in and Disagreements with Accountants  on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

1. Disclosure Controls and Procedures

Our management, with the participation of our principal executive officer and principal financial

officer, has evaluated the effectiveness  of  our disclosure controls and procedures (as defined in
Rules 13a-15(e) or 15d-15(e) under the Securities Exchange  Act of 1934,  as amended) as  of the end of
the period covered by this Annual Report on  Form 10-K. Based on such evaluation, our principal
executive officer and principal financial officer have  concluded that,  as of the  end of such  period, our
disclosure controls and procedures were  adequate and effective.

2.

Internal Control Over Financial Reporting

(a) Management’s Annual Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal  control over
financial reporting. Internal control over financial reporting is defined in Rules 13a-15(f)  and 15d-15(f)
under the Exchange Act as a process  designed by, or under the supervision of, our principal executive
and principal financial officers and effected by our  board  of directors, management and  other
personnel to provide reasonable assurance regarding the reliability of  financial  reporting and  the
preparation of financial statements for external purposes in  accordance with generally  accepted
accounting principles in the U.S. and  includes those policies and procedures that:

(cid:127) pertain to the maintenance of records that in reasonable detail accurately and fairly  reflect our

transactions and dispositions of our assets;

(cid:127) provide reasonable assurance that transactions are recorded  as necessary to permit preparation

of financial statements in accordance with generally accepted  accounting principles, and  that  our
receipts  and expenditures are being made  only  in accordance with authorizations of our
management and directors; and

(cid:127) provide reasonable assurance regarding prevention or timely detection of  unauthorized

acquisition, use or  disposition of our assets  that could  have a material  effect  on the financial
statements.

Because of its inherent limitations, internal control over  financial  reporting may not prevent or
detect misstatements. Projections of any  evaluation of effectiveness  to  future periods are  subject to the
risks that controls may become inadequate because of changes  in conditions, or that the  degree  of
compliance with the policies or procedures may deteriorate.

Management assessed the effectiveness of our internal control over financial  reporting as of

June 30, 2014. In making this assessment,  management  used  the criteria established in Internal
Control—Integrated Framework issued by the Committee of Sponsoring Organizations  of  the Treadway
Commission, or COSO, in 1992.

Based on this assessment, management has concluded that, as of  June  30, 2014 our internal control

over financial reporting is effective.

Ernst & Young LLP, our independent  registered public accounting firm, has issued  a report on the

effectiveness of our internal control over  financial reporting  as of June 30,  2014. This  report appears
immediately below.

109

(b) Attestation Report of the Independent Registered Public Accounting Firm

Report of Independent Registered Public  Accounting Firm

The Board of Directors and Shareholders  of ImmunoGen, Inc.

We  have audited ImmunoGen, Inc.’s  internal  control  over financial reporting  as of June 30, 2014,

based on criteria established in Internal Control—Integrated  Framework issued by the Committee of
Sponsoring Organizations of the Treadway Commission (1992 framework) (the COSO criteria).
ImmunoGen, Inc.’s management is responsible for maintaining effective internal control over  financial
reporting, and for its assessment of the  effectiveness  of  internal control  over financial reporting
included in the accompanying Management’s  Annual  Report  on Internal  Control  Over  Financial
Reporting. Our responsibility is to express an  opinion on  the company’s internal control over financial
reporting based on our audit.

We  conducted our audit in accordance with the standards of  the Public Company Accounting
Oversight Board (United States). Those  standards require that we  plan and perform the audit to obtain
reasonable assurance about whether  effective  internal control over financial reporting was maintained
in all material respects. Our audit included  obtaining an understanding  of internal control  over
financial reporting, assessing the risk that a  material weakness exists, testing and evaluating the design
and operating effectiveness of internal control based  on the assessed risk, and performing such other
procedures as we considered necessary in  the circumstances. We  believe that our audit provides a
reasonable basis for our opinion.

A company’s internal control over financial reporting is a process designed to provide  reasonable

assurance regarding the reliability of  financial  reporting and the preparation  of  financial  statements  for
external  purposes in accordance with  generally accepted accounting  principles. A company’s internal
control over financial reporting includes those policies and procedures that (1)  pertain to the
maintenance of records that, in reasonable  detail, accurately and fairly reflect the  transactions and
dispositions of the assets of the company; (2) provide reasonable assurance that transactions  are
recorded  as necessary to permit preparation of financial statements in  accordance with generally
accepted accounting principles, and that receipts and expenditures of the company are being made  only
in accordance with authorizations of management and directors of the company; and  (3) provide
reasonable assurance regarding prevention  or timely detection of unauthorized acquisition, use, or
disposition of the company’s assets that  could have a material effect on the financial statements.

Because of its inherent limitations, internal control over  financial  reporting may not prevent or

detect misstatements. Also, projections  of any evaluation  of  effectiveness to future periods are  subject
to the risk that controls may become inadequate  because of changes in conditions, or  that  the degree
of compliance with the policies or procedures may deteriorate.

In our opinion, ImmunoGen, Inc. maintained, in all material respects, effective internal control

over financial reporting as of June 30, 2014  based on the COSO criteria.

We  also have audited, in accordance  with the standards of  the Public Company Accounting
Oversight Board (United States), the  consolidated balance sheets of ImmunoGen, Inc.  as of June 30,
2014 and 2013, and the related consolidated  statements  of operations  and  comprehensive loss,
shareholders’ equity, and cash flows for  each of the three years  in the  period ended  June  30, 2014 and
our  report dated August 28, 2014 expressed  an unqualified  opinion thereon.

/s/ Ernst & Young LLP

Boston, Massachusetts
August 28, 2014

110

(c) Changes in Internal Control Over  Financial Reporting

There have not been any changes in our internal control  over  financial reporting (as such term is
defined in Rules 13a-15(f) and 15d-15(f)  under the Exchange  Act) during the quarter ended June 30,
2014 that have materially affected, or  are  reasonably likely to materially affect, our internal  control
over financial reporting.

3. Limitations on the Effectiveness of  Controls

Our management, including our principal  executive officer and principal financial officer, does  not

expect that our disclosure controls and  procedures or its  internal control  over financial reporting will
prevent all error and all fraud. A control  system,  no matter  how  well conceived and operated, can
provide only reasonable, not absolute,  assurance that the objectives of the  control system are  met.
Further, the design of a control system must reflect  the fact that there are resource constraints, and  the
benefits of controls must be considered relative to their costs. Because  of the inherent  limitations in all
control systems, no evaluation of controls can  provide absolute assurance  that  all  control issues  and
instances of fraud, if any, within an organization have been detected. These inherent limitations include
the realities that judgments in decision-making can be faulty,  and that breakdowns can  occur because of
simple error or mistake.

Additionally, controls can be circumvented by the  individual acts of some  persons, by collusion of
two or more people, or by management override of  the control. The design  of  any system of controls
also is based in part upon certain assumptions about  the likelihood of future events,  and there  can be
no assurance that any design will succeed in achieving  our stated  goals under all potential future
conditions. Over time, controls may become inadequate  because of changes  in conditions, or  the degree
of compliance with the policies or procedures may deteriorate. Because of  the inherent limitations in a
cost-effective control system, misstatements due to error or fraud may occur and  not  be  detected.

Item 9B. Other Information

None.

111

PART III

The information called for by Part III of Form 10-K  (Item  10—Directors, Executive Officers and

Corporate Governance of the Registrant, Item  11—Executive Compensation, Item 12—Security
Ownership of Certain Beneficial Owners  and Management  and  Related Stockholder  Matters, Item 13—
Certain Relationships and Related Transactions, and  Director Independence, and  Item 14—Principal
Accounting Fees and Services) is incorporated by reference from our proxy statement related to our
2014 annual meeting of shareholders,  which will be filed  with the  Securities  and Exchange  Commission
not later than October 28, 2014 (120 days after the  end of the fiscal year covered by this Annual
Report on Form 10-K), except that information required  by Item 10 concerning  our  executive officers
appears  in Part I, Item 3.1 of this Annual Report on Form  10-K.

112

Item 15. Exhibits, Financial Statement Schedules

(a) Financial Statements:

PART IV

(1) See ‘‘Index to Consolidated Financial Statements’’ at  Item  8 of this Annual Report  on

Form 10-K. Schedules not included herein are omitted  because they  are  not applicable or  the
required information appears in the accompanying Consolidated Financial  Statements or Notes
thereto.

(2) The following schedule is filed as  part  of  this  Annual Report  on Form 10-K:

Schedule II—Valuation and Qualifying Accounts for the years ended  June 30, 2014, 2013  and 2012.

(3) See Exhibit Index following the signature page to this Annual Report  on Form 10-K.

113

Pursuant to the requirements of Section  13  or 15(d) of the Securities Exchange Act of 1934, the

Registrant has duly caused this report to be signed on its  behalf  by the undersigned,  thereunto duly
authorized.

SIGNATURES

IMMUNOGEN, INC.

By:

/s/ DANIEL M. JUNIUS

Daniel M. Junius
President and
Chief Executive Officer
(Principal Executive Officer)

Dated: August 28, 2014

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has  been signed

below by the following persons on behalf of  the Registrant in the  capacities and on  the dates  indicated.

Signature

Title

Date

/s/ DANIEL M. JUNIUS

Daniel M. Junius

/s/ DAVID B. JOHNSTON

David B. Johnston

/s/ STEPHEN MCCLUSKI

Stephen McCluski

/s/ MARK GOLDBERG, M.D.

Mark Goldberg, M.D.

/s/ DEAN MITCHELL

Dean Mitchell

/s/ NICOLE ONETTO, M.D.

Nicole Onetto, M.D.

/s/ KRISTINE PETERSON

Kristine Peterson

/s/ HOWARD PIEN

Howard Pien

/s/ JOSEPH VILLAFRANCA PH.D.

Joseph  Villafranca, Ph.D.

/s/ RICHARD WALLACE

Richard Wallace

President, Chief Executive Officer and Director

(Principal Executive Officer)

August 28, 2014

Executive Vice President and

Chief Financial Officer
(Principal Financial and Accounting Officer)

August 28, 2014

Chairman of the Board of Directors

August 28, 2014

Director

August 28,  2014

Director

August 28,  2014

Director

August 28,  2014

Director

August 28,  2014

Director

August 28,  2014

Director

August 28,  2014

Director

August 28,  2014

114

EXHIBIT INDEX

Exhibit
Number

Exhibit Description

3.1

Restated Articles  of Organization,  as amended

3.1(a)

Articles of Amendment

3.2

4.1

4.2

10.1

10.1(a)

10.1(b)

10.1(c)

10.1(d)

10.1(e)

10.1(f)

10.1(g)

10.1(h)

10.1(i)

Amended and Restated By-Laws

Article 4 of Restated Articles of Organization,  as
amended (see Exhibit 3.1)

Form of Common Stock certificate

Leases dated as of December 1, 1986  and  June 21,
1988 by and between James H. Mitchell, Trustee  of
New Providence Realty Trust, lessor,  and Charles
River Biotechnical Services, Inc. (‘‘Lessee’’),
together with Assignment of Leases dated  June 29,
1989 between Lessee and the Registrant

First Amendment  to Lease dated May  9, 1991  by
and between James H. Mitchell, Trustee  of New
Providence Realty Trust, lessor, and  the  Registrant

Confirmatory Second Amendment  to  Lease dated
September 17, 1997 by and between James H.
Mitchell, Trustee of  New  Providence Realty Trust,
lessor, and the Registrant

Third Amendment and Partial Termination  of  Lease
dated as of August 8, 2000 by and between
James H. Mitchell, Trustee of New Providence
Realty Trust, lessor, and the  Registrant

Fourth Amendment to Lease dated  as of  October 3,
2000 by and between James H. Mitchell, Trustee  of
New Providence Realty Trust, lessor,  and the
Registrant

Fifth Amendment to Lease dated as of  June 7,  2001
by and between James H. Mitchell, Trustee  of New
Providence Realty Trust, lessor, and  the  Registrant

Sixth Amendment  to Lease dated as  of April 30,
2002 by and between Bobson 333 L.L.C.,  lessor,  and
the Registrant

Seventh Amendment to Lease dated as  of
October 20, 2005 by and  between Bobson  333
L.L.C., lessor, and  the Registrant

Eighth Amendment to Lease dated as of
February 21, 2007 by and between Bobson 333
L.L.C., lessor, and  the Registrant

Ninth  Amendment to Lease dated  as  of
November 17, 2010 by and between Bobson  333
LLC and the Registrant

115

Filed
with this
Form 10-K Form

Incorporated by Reference

Filing Date
with SEC

Exhibit
Number

10-Q

10-Q

8-K

April 30,  2010

January  30, 2013

April  6,  2007

S-1 November 15,  1989
(File No.  33-31219)

3.1

3.1

3.1

4.2

S-1 September 22,  1989
(File No. 33-31219)

10.10

S-1 November  6,  1991
(File No. 33-43725)

10.10a

10-K September  26, 1997

10.10

10-K September 2,  2008

10.1(c)

10-K September  2, 2008

10.1(d)

10-K September  2, 2008

10.1(e)

10-K September  2, 2008

10.1(f)

10-K September 2,  2008

10.1(g)

10-K September 2,  2008

10.1(h)

8-K November  18, 2010

10.1

Exhibit
Number

10.2

10.2(a)

10.2(b)

Exhibit Description

Lease Agreement, dated as of July  27,  2007, by and
between Intercontinental Fund III  830  Winter
Street LLC, landlord, and the Registrant

First Amendment  to Lease Agreement  dated  as of
December 9, 2013, by and between Intercontinental
Fund III 830 Winter Street LLC, landlord,  and  the
Registrant

Second Amendment to Lease Agreement  dated as
of April 28, 2014, by and between  Intercontinental
Fund III 830 Winter Street LLC, landlord,  and  the
Registrant

Filed
with this
Form 10-K Form

Incorporated by Reference

Filing Date
with SEC

Exhibit
Number

10-Q November  7, 2007

10.2

10-Q

February  5,  2014

10.1

10-Q

May  2, 2014

10.1

10.3*

License Agreement dated  effective  May 2,  2000  by
and between the  Registrant  and Genentech, Inc.

10-Q

October  31, 2011

10.1

10.3(a)* Amendment to License Agreement for  Anti-HER2

10-K

August  28,  2006

10.32

Antibodies, dated as of May 3, 2006, between the
Registrant and Genentech, Inc.

10.3(b)* Amendment to License Agreements  made effective

10-Q

May  7, 2009

10.1

10.3(c)

10.4*

as of March 11, 2009, between  the  Registrant and
Genentech, Inc.

Third Amendment to License Agreement for
Anti-HER2 Antibodies, made effective as of
December 18, 2012, between the Registrant  and
Genentech, Inc.

Collaboration and License Agreement dated  as  of
July 30, 2003 by and between the Registrant and
sanofi-aventis U.S. LLC (as successor-in-interest  to
Aventis Pharmaceuticals Inc.)

10.4(a)* Amendment No. 1, dated as of August  31,  2006, to
the Collaboration and License Agreement between
the Registrant and sanofi-aventis U.S. LLC

10.4(b)* Amendment No. 2, dated as of December 7,  2007,

to the Collaboration and License Agreement
between the Registrant and sanofi-aventis  U.S. LLC

10.4(c)*

Amendment No. 3, dated as of August  31,  2008, to
the Collaboration and License Agreement between
the Registrant and sanofi-aventis U.S. LLC

10.5*

10.6*

Option and License Agreement dated  as  of
December 21, 2006 by and between the Registrant
and sanofi-aventis U.S. LLC

Collaborative Development  and License  Agreement
dated as of July 7, 2006 by and between the
Registrant and Biotest AG

X

X

X

X

10-Q

January  30,  2013

10.11

10-Q

February  8,  2007

10.2

10-Q November  3,  2006

10.2

10.6(a)* Amendment No. 1, dated August 23,  2006, to

10-Q November 3,  2006

10.3

Collaborative Development and License Agreement
by and between the Registrant and Biotest  AG

116

Exhibit
Number

10.7*

10.8*

10.8(a)*

10.9*

10.10*

Exhibit Description

Development and License Agreement  dated  as of
October 20, 2008 by and  between the Registrant  and
Bayer HealthCare AG

Multi-Target Agreement dated as of  October 8,  2010
by and between the Registrant and Novartis
Institutes for BioMedical Research, Inc.

First Amendment,  effective  as of  March  29, 2013,  to
Multi-Target Agreement by and between  the
Registrant and Novartis  Institutes for  BioMedical
Research, Inc.

Clinical Supply Agreement effective  as  of
December 12, 2010 by and between the Registrant
and Societ´a Italiana Corticosteroidi S.r.l. (Sicor)

Multi-Target Agreement dated as of December 19,
2011 by and between the Registrant  and Eli  Lilly
and Company

Filed
with this
Form 10-K Form

Incorporated by Reference

Filing Date
with SEC

Exhibit
Number

10-Q/A

October  10, 2012

10.1

10-Q/A

October  10, 2012

10.2

10-Q

May  6,  2013

10.1

10-Q

February  8, 2011

10.1

10-Q/A

October 10, 2012

10.3

10.10(a)* First Amendment to Agreements dated  as of

10-Q

February 5, 2014

10.2

December 9, 2013  by and between the Registrant
and Eli Lilly and Company

10.11†

Restated Stock Option Plan

10.11(a)† Form of Incentive Stock Option Agreement

10.11(b)† Form of Non-Qualified Stock  Option Agreement

10.12†

2006 Employee, Director and Consultant Equity
Incentive Plan, as amended and restated through
November 13, 2012

8-K

8-K

8-K

February  7, 2006

February 7,  2006

February 7, 2006

8-K November  16, 2012

10.1

10.2

10.3

10.1

10.12(a)† Form of Incentive Stock Option Agreement  for

S-8 November 15,  2006

99.4

Executives

10.12(b)† Form of Non-Qualified Stock  Option Agreement for

S-8 November 15,  2006

99.5

Executives

10.12(c)† Form of Non-Qualified Stock  Option Agreement for

10-Q

October 29, 2010

10.1

Directors

10.12(d)† Form of Director Deferred Stock Unit  Agreement

10-Q

October 29, 2010

10.1

10.12(e)† Form of Incentive Stock Option Agreement  for all

10-K

August 29, 2012 10.14(g)

employees (including executives)

10.12(f)† Form of Non-Qualified Stock  Option Agreement for

10-K

August 29, 2012 10.14(h)

all employees (including executives)

10.12(g)† Form of Non-Qualified Stock  Option Agreement for

10-K

August 29, 2012 10.14(i)

Directors

10.12(h)† Form of Restricted Stock Agreement  for all
employees (including executives)

S-8 November 21,  2012

99.1

10.13†

2001 Non-Employee Director Stock Plan

S-8 December 18,  2001

99

117

Exhibit
Number

10.14†

10.15†

10.16†

10.17†

10.18†

10.19†

10.20†

10.21†

Exhibit Description

2004 Non-Employee Director Compensation  and
Deferred Stock Unit Plan, as amended  on
September16, 2009

Form of Proprietary Information,  Inventions and
Competition Agreement between the Registrant and
each of its executive  officers

Change in Control Severance Agreement dated  as
of November 30, 2012 between the Registrant  and
Craig Barrows

Change in Control Severance Agreement dated  as
of November 30, 2012 between the Registrant  and
Daniel M. Junius

Change in Control Severance Agreement dated  as
of November 30, 2012 between the Registrant  and
John M. Lambert

Change in Control Severance Agreement dated  as
of November 30, 2012 between the Registrant  and
Charles Q. Morris

Change in Control Severance Agreement dated  as
of November 30, 2012 between the Registrant  and
James J. O’Leary

Change in Control Severance Agreement dated  as
of November 30, 2012 between the Registrant  and
Peter Williams

10.22†

Compensation Policy for Non-Employee Directors,
as amended through November  12,  2013

10.23†

Summary of Annual Bonus Program

10.24†

10.25†

10.26†

10.27†

10.28†

10.29†

Employment offer letter between the  Registrant and
Charles Q. Morris

Employment Agreement  dated as  of  November 26,
2012 between the Registrant and Charles  Q. Morris

Transition and  Separation Agreement  dated  as  of
September 13, 2013 between the Registrant  and
Gregory D. Perry

Employment offer letter between the  Registrant and
David B. Johnston

Employment Agreement  dated as  of  December  30,
2013 between the Registrant and David  B. Johnston

Change in Control Severance Agreement dated  as
of December 30, 2013 between the  Registrant and
David B. Johnston

Filed
with this
Form 10-K Form

Incorporated by Reference

Filing Date
with SEC

Exhibit
Number

10-Q November  4,  2009

10.1

10-Q

February  8,  2007

10.15

10-Q

January 30,  2013

10.1

10-Q

January 30,  2013

10.2

10-Q

January 30,  2013

10.3

10-Q

January 30,  2013

10.4

10-Q

January 30,  2013

10.5

10-Q

January 30,  2013

10.7

10-Q

February 5,  2014

10.3

8-K

June  16,  2014

10-Q

January 30,  2013

99.1

10.9

10-Q

January 30,  2013

10.10

10-Q

October  29. 2013

10.1

10-Q

February 5,  2014

10.4

10-Q

February 5,  2014

10.5

10-Q

February 5,  2014

10.6

10.30†

Employment offer letter between the  Registrant and
Ellie Harrison

10-Q

May  2, 2014

10.2

118

Filed
with this
Form 10-K Form

Incorporated by Reference

Filing Date
with SEC

Exhibit
Number

10-Q

May  2, 2014

10.3

10-K

August  30,  2007

21

X

X

X

X

Exhibit
Number

10.31†

21

23

31.1

31.2

32

Exhibit Description

Change in Control Severance Agreement dated  as
of February 20, 2014  between the Registrant  and
Ellie Harrison

Subsidiaries of the Registrant

Consent of Ernst & Young LLP

Certification of the Chief Executive  Officer  pursuant
to Section 302 of the Sarbanes-Oxley  Act  of 2002

Certification of the Chief Financial  Officer  pursuant
to Section 302 of the Sarbanes-Oxley  Act  of 2002

Certifications of Chief Executive Officer  and  Chief
Financial Officer pursuant to Section  906 of  the
Sarbanes-Oxley Act of 2002

101.INS

XBRL Instance Document

101.SCH XBRL Taxonomy Extension  Schema

101.CAL XBRL Taxonomy Extension Calculation Linkbase

101.DEF XBRL Taxonomy Extension Definition  Linkbase

101.LAB XBRL Taxonomy Extension Label  Linkbase

101.PRE XBRL Taxonomy Extension  Presentation  Linkbase

*

†

Portions of this Exhibit were omitted, as  indicated by  [***],  and have been  filed  separately  with  the Secretary
of the Commission pursuant to the Registrant’s application  requesting  confidential  treatment.

Exhibit is a management contract  or compensatory  plan,  contract  or  arrangement required  to  be  filed  as  an
exhibit to the annual report on Form 10-K.

119

IMMUNOGEN, INC.

SCHEDULE II—VALUATION AND QUALIFYING ACCOUNTS

(In thousands)

COLUMN A—DESCRIPTION

Inventory Valuation Allowance

Year End June 30, 2014 . . . . . . . . . . . . . . . . . . .
Year End June 30, 2013 . . . . . . . . . . . . . . . . . . .
Year End June 30, 2012 . . . . . . . . . . . . . . . . . . .

COLUMN B

COLUMN C—
ADDITIONS

COLUMN D

COLUMN  E

Balance at
Beginning
of Period

$ 810
$1,291
$1,993

Charged
to Costs
and
Expenses

$364
$798
$786

Use of
Zero
Value
Inventory

$ (513)
$(1,279)
$(1,488)

Balance at
End of
Period

$ 661
$ 810
$1,291

120

EXHIBIT 31.1

CERTIFICATIONS UNDER SECTION 302

I, Daniel M. Junius, certify that:

1.

I have reviewed this Annual Report  on Form 10-K of ImmunoGen, Inc.;

2. Based on my knowledge, this report does  not  contain any untrue statement  of  a material fact or

omit to state a material fact necessary to make the statements made,  in light  of the circumstances
under which such statements were made, not misleading with respect to the period  covered by this
report;

3. Based on my knowledge, the financial statements, and  other financial  information included in  this
report, fairly present in all material respects the financial  condition, results of operations and  cash
flows of the registrant as of, and for, the periods presented in  this report;

4. The registrant’s other certifying  officer(s)  and  I are responsible for establishing and maintaining
disclosure controls and procedures (as defined in  Exchange  Act Rules 13a-15(e) and 15d-15(e))
and internal control over financial reporting  (as  defined in  Exchange Act  Rules 13a-15(f)  and
15d-15(f)) for the registrant and have:

a)

designed such disclosure controls  and procedures, or  caused such disclosure controls and
procedures to be designed under  our supervision,  to  ensure that material  information relating
to the registrant, including its consolidated subsidiaries, is made  known to us by others within
those entities, particularly during  the period in which  this  report is being prepared;

b) designed such internal control over financial  reporting, or caused such internal control over

financial reporting to be designed under  our  supervision, to  provide reasonable assurance
regarding the reliability of financial reporting  and  the preparation of financial statements for
external  purposes in accordance with generally accepted  accounting  principles;

c)

evaluated the effectiveness of the registrant’s disclosure controls and  procedures and
presented in this report our conclusions about  the effectiveness of the disclosure controls and
procedures, as of the end of the period  covered by this report based on such evaluation; and

d) disclosed in this report any change in  the registrant’s internal control over  financial  reporting

that occurred during the registrant’s  most recent fiscal  quarter (the registrant’s fourth fiscal
quarter in the case of an annual report) that  has materially  affected, or is reasonably likely to
materially affect, the registrant’s internal control  over financial reporting; and

5. The registrant’s other certifying  officer(s)  and  I have disclosed,  based on our  most recent

evaluation of internal control over financial reporting,  to  the registrant’s auditors and the audit
committee of the registrant’s board of directors (or persons performing the equivalent functions):

a)

b)

all significant deficiencies and material  weaknesses in the design  or  operation  of internal
control over financial reporting which  are reasonably likely  to  adversely affect  the registrant’s
ability to record, process, summarize and report financial information; and

any fraud, whether or not material, that involves management  or other employees who have a
significant role in the registrant’s internal control over  financial  reporting.

Date: August 28, 2014

/s/ DANIEL M. JUNIUS

Daniel M. Junius
President and Chief Executive Officer
(Principal Executive Officer)

EXHIBIT 31.2

CERTIFICATIONS UNDER SECTION 302

I, David B. Johnston, certify that:

1.

I have reviewed this Annual Report  on Form 10-K of ImmunoGen, Inc.;

2. Based on my knowledge, this report does  not  contain any untrue statement  of  a material fact or

omit to state a material fact necessary to make the statements made,  in light  of the circumstances
under which such statements were made, not misleading with respect to the period  covered by this
report;

3. Based on my knowledge, the financial statements, and  other financial  information included in  this
report, fairly present in all material respects the financial  condition, results of operations and  cash
flows of the registrant as of, and for, the periods presented in  this report;

4. The registrant’s other certifying  officer(s)  and  I are responsible for establishing and maintaining
disclosure controls and procedures (as defined in  Exchange  Act Rules 13a-15(e) and 15d-15(e))
and internal control over financial reporting  (as  defined in  Exchange Act  Rules 13a-15(f)  and
15d-15(f)) for the registrant and have:

a)

designed such disclosure controls  and procedures, or  caused such disclosure controls and
procedures to be designed under  our supervision,  to  ensure that material  information relating
to the registrant, including its consolidated subsidiaries, is made  known to us by others within
those entities, particularly during  the period in which  this  report is being prepared;

b) designed such internal control over financial  reporting, or caused such internal control over

financial reporting to be designed under  our  supervision, to  provide reasonable assurance
regarding the reliability of financial reporting  and  the preparation of financial statements for
external  purposes in accordance with generally accepted  accounting  principles;

c)

evaluated the effectiveness of the registrant’s disclosure controls and  procedures and
presented in this report our conclusions about  the effectiveness of the disclosure controls and
procedures, as of the end of the period  covered by this report based on such evaluation; and

d) disclosed in this report any change in  the registrant’s internal control over  financial  reporting

that occurred during the registrant’s  most recent fiscal  quarter (the registrant’s fourth fiscal
quarter in the case of an annual report) that  has materially  affected, or is reasonably likely to
materially affect, the registrant’s internal control  over financial reporting; and

5. The registrant’s other certifying  officer(s)  and  I have disclosed,  based on our  most recent

evaluation of internal control over financial reporting,  to  the registrant’s auditors and the audit
committee of the registrant’s board of directors (or persons performing the equivalent functions):

a)

b)

all significant deficiencies and material  weaknesses in the design  or  operation  of internal
control over financial reporting which  are reasonably likely  to  adversely affect  the registrant’s
ability to record, process, summarize and report financial information; and

any fraud, whether or not material, that involves management  or other employees who have a
significant role in the registrant’s internal control over  financial  reporting.

Date: August 28, 2014

/s/ DAVID B. JOHNSTON

David B. Johnston
Executive Vice President and Chief Financial Officer
(Principal Financial and Accounting Officer)

EXHIBIT 32

CERTIFICATIONS UNDER SECTION 906

Pursuant to section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b)  of

section 1350, chapter 63 of title 18, United States Code), each of the undersigned officers of
ImmunoGen, Inc., a Massachusetts corporation (the ‘‘Company’’), does  hereby certify,  to  such officer’s
knowledge, that:

The Annual Report for the year ended June  30, 2014 (the ‘‘Form  10- K’’) of the  Company fully

complies with the requirements of Section  13(a) or  15(d) of  the Securities Exchange Act of 1934, and
the information contained in the Form 10-K fairly  presents, in all material  respects, the financial
condition and results of operations of  the Company.

Dated: August 28, 2014

/s/ DANIEL M. JUNIUS

Daniel M. Junius
President and Chief Executive Officer
(Principal Executive Officer)

Dated: August 28, 2014

/s/ DAVID B. JOHNSTON

David B. Johnston
Executive Vice President and Chief Financial Officer
(Principal Financial and Accounting Officer)

A signed original of this written statement required  by  Section 906 has  been provided to the

Company and will be retained by the  Company and furnished to the  Securities and Exchange
Commission or its staff upon request.

IMMUNOGEN, INC.

Stock Price Performance Graph

The graph and table below compare the annual percentage change in our cumulative total

shareholder return on our common stock  for the period from June 30,  2009 through June 30,  2014 (as
measured by dividing (i) the sum of (A)  the cumulative  amount of dividends for  the measurement
period, assuming dividend reinvestment,  and (B)  the difference between  our share price at the end  and
the beginning of the measurement period;  by (ii)  the share  price at the beginning of the measurement
period) with the total cumulative return of the NASDAQ  Stock Market  Index  (U.S.)  and the  NASDAQ
Pharmaceutical Stocks Total Return Index during such  period.  We have  not  paid any  dividends  on our
common stock, and no dividends are included  in the representation of our performance.  The  stock
price performance on the graph below  is  not  necessarily indicative of future price performance. This
graph is not ‘‘soliciting material,’’ is not  deemed  filed  with the Commission  and is not to be
incorporated by reference in any of our  filings under  the Securities Act of 1933, or the Securities
Exchange Act of 1934, whether made  before  or after  the date hereof and irrespective of any general
incorporation language in any such filing.  Information  used  on the graph for  the NASDAQ
Pharmaceutical Stocks Total Return Index and  the NASDAQ  Stock  Market Index (U.S.) was prepared
by the Center for Research in Security Prices, a  source believed to be reliable, but  we are  not
responsible for any errors or omissions  in such information.

350.00

300.00

250.00

200.00

150.00

100.00

50.00

0.00

2009

2010

2011

2012

2013

2014

ImmunoGen Inc.

NASDAQ Stock Market (US Companies)

NASDAQ Pharmaceutical Index

21AUG201416164006

IMMUNOGEN, INC.
NASDAQ STOCK MARKET INDEX  (U.S.)
NASDAQ PHARMACEUTICAL STOCKS  TOTAL

. . . . . . . . . . . . . . . . . . . . . . . . . $100.00 $107.54 $141.42 $194.20 $192.46 $137.47
. . . . . . . . . $100.00 $116.08 $154.71 $168.54 $198.33 $258.88

RETURN INDEX* . . . . . . . . . . . . . . . . . . . . . . . . . $100.00 $103.17 $133.98 $157.28 $217.45 $308.69

2009

2010

2011

2012

2013

2014

*

This index represents a group of peer issuers  compiled by the  Center  for Research  in  Security  Prices.

The above graph and table assume $100 invested on  June  30, 2009 with all dividends reinvested, in

each  of our common stock, the NASDAQ Stock Market Index (U.S.) and the NASDAQ
Pharmaceutical Stocks Total Return Index. Upon written request by any  shareholder, we  will  promptly
provide a list of the companies comprising  the NASDAQ Pharmaceutical Stocks  Total Return Index.