ImmunoGen
Annual Report 2020

A N N U A L
R E P O R T   2 0 2 0

NASDAQ: IMGN

MESSAGE TO OUR SHAREHOLDERS

Despite the challenges of the pandemic, 2020 was a 

transformative year for ImmunoGen. We rapidly evolved how we 
work to meet the needs of our patients through uninterrupted 

development of our portfolio on a global scale, while ensuring the 
well-being of our employees. As a member of the broader biopharma 
community, we are proud to be part of an industry that delivered 
innovation at an extraordinary pace to abate the COVID-19 health crisis. 

Over the last year, we made significant progress on our strategic 
priorities to advance the registration studies for our lead program, 
mirvetuximab soravtansine, align on a path to full approval for our 
second pivotal program, IMGN632, accelerate our portfolio of earlier 
stage product candidates, strengthen our balance sheet, and expand 
our capabilities through partnerships. Furthermore, we bolstered our 
management team with the appointments of Stacy Coen as our new 
Chief Business Officer and Susan Altschuller, Ph.D., as our new Chief 
Financial Officer. 

PROGRESSING REGISTRATION STUDIES FOR MIRVETUXIMAB
SORAYA — At the height of the first wave of the pandemic, we 
launched SORAYA, our Phase 3 single-arm pivotal trial evaluating 
mirvetuximab monotherapy in women with folate receptor alpha 
(FRα)-high platinum-resistant ovarian cancer, who have been previously 
treated with Avastin® (bevacizumab). Through the remarkable efforts 
of our team and collaborators, we overcame some initial challenges 
with site activation and expect top-line pivotal data later this year. 
With positive results, and subject to review by the U.S. Food and Drug 
Administration (FDA), we anticipate potential accelerated approval of 
mirvetuximab in 2022.
MIRASOL — In tandem, we progressed our Phase 3 randomized 
confirmatory study, MIRASOL, which would support full approval of 
mirvetuximab in women with platinum-resistant ovarian cancer. This 
study is evaluating mirvetuximab monotherapy compared to single-
agent chemotherapy in 430 patients with FRα-high platinum-resistant 
ovarian cancer, who have received up to three prior regimens. We 
anticipate top-line data from MIRASOL in 2022 and potential full 
approval in 2023.

EXPANDING MIRVETUXIMAB INTO EARLIER LINES 
OF THERAPY
FORWARD II — Beyond our anticipated monotherapy label, we 
continue to advance combination regimens with mirvetuximab in our 
FORWARD II cohorts as an avenue to support label expansion and move 
mirvetuximab into earlier lines of therapy in ovarian cancer. At the 2020 
American Society of Clinical Oncology (ASCO) Virtual Scientific Program, 
we presented compelling initial efficacy and safety data from the 
combination of mirvetuximab with bevacizumab in platinum-agnostic, 
recurrent ovarian cancer and plan to present mature data from this 
cohort at ASCO 2021. Additionally, at the 2020 European Society for 
Medical Oncology (ESMO) Virtual Congress, we presented final data 
from our triplet cohort evaluating mirvetuximab in combination with 
carboplatin and bevacizumab, demonstrating encouraging anti-tumor 
activity in recurrent platinum-sensitive ovarian cancer.

With the data generated from FORWARD II and other ongoing studies, 
we plan to seek compendia listings for these combination regimens in 
close proximity to the initial monotherapy approval of mirvetuximab. 
Looking ahead, we continue to evaluate opportunities to generate 
further data for potential formal label expansion as we position 
mirvetuximab as the combination agent of choice in ovarian cancer.  

PATHWAY TO APPROVAL FOR OUR SECOND PIVOTAL PROGRAM

We also made significant progress with IMGN632, our CD123-
targeting antibody-drug conjugate (ADC) in development for blastic 
plasmacytoid dendritic cell neoplasm (BPDCN) and acute myeloid 
leukemia (AML).  

In October 2020, we received Breakthrough Therapy Designation from 
FDA for IMGN632 in BPDCN, a rare and aggressive hematologic cancer. 
At the 2020 American Society of Hematology (ASH) Annual Meeting 
in December, we presented updated safety and efficacy data from 

the Phase 1/2 study of IMGN632 in patients with relapsed/refractory 
(R/R) BPDCN, which support its potential as a best-in-class treatment 
option in this setting. Importantly, we aligned with FDA on a path to 
full approval with the addition of a pivotal frontline cohort of BPDCN 
patients and anticipate top-line data and potential approval in 2022. 

We are also pursuing a Phase 1b/2 study of IMGN632 in combination 
with Vidaza® (azacitidine) and Venclexta® (venetoclax) in R/R and 
frontline AML patients, and as a monotherapy in minimal residual 
disease positive (MRD+) AML following frontline induction therapy.  
We plan to present additional BPDCN and AML data at ASH later this year.  

ADVANCING OUR EARLIER-STAGE PORTFOLIO 
OF INNOVATIVE ADCs

In collaboration with MacroGenics, we are codeveloping IMGC936, our 
first-in-class ADAM9-targeting ADC, in a wide range of solid tumors. 
In November 2020, we enrolled the first patient in a Phase 1 dose-
escalation study of IMGC936 and anticipate initial data from this study 
by the end of 2021 or early 2022.

We also advanced our next-generation anti-FRα ADC, IMGN151, into 
preclinical development. IMGN151 has the potential to address patient 
populations with lower levels of FRα expression, including tumor 
types outside of ovarian cancer. At the 2020 American Association 
for Cancer Research (AACR) Annual Meeting in April, we presented 
data demonstrating IMGN151’s potent anti-tumor activity in preclinical 
ovarian cancer models and other FRα-positive tumor types. We expect 
to submit the investigational new drug (IND) application for IMGN151 
by the end of this year.

PARTNERING TO BRING NOVEL TARGETED THERAPIES 
TO MORE PATIENTS 

Partnering remains a key element of our strategy, and we continued 
our strong track record of value-creating transactions in 2020. In 
October, we announced a strategic collaboration with Huadong 
Medicine to develop and commercialize mirvetuximab in Greater 
China. This collaboration provides access to the second largest 
pharmaceutical market in the world and reflects the potential of 
mirvetuximab to deliver meaningful outcomes to ovarian cancer 
patients globally. The IND application for mirvetuximab in China has 
been accepted by the National Medical Products Administration 
(NMPA), and we look forward to working closely with Huadong to  
bring mirvetuximab to patients in the region.

TRANSITIONING TO A FULLY-INTEGRATED 
ONCOLOGY COMPANY

Building upon our progress in 2020, we enter this year with significant 
momentum, multiple near-term catalysts, and a balance sheet 
strengthened by the addition of $175 million generated through 
business development and proceeds from our At-the-Market (ATM) 
facility over the last two quarters. Taken together, our pivotal 
programs, experienced management team, and strong cash balance 
position us well to execute on our strategy and transition ImmunoGen 
to a fully-integrated oncology company with two products on the 
market in 2022. 

In closing, I thank the team at ImmunoGen for their commitment to 
advancing our portfolio under the extraordinary circumstances of the 
past year, and our board members and shareholders for their continued 
support. We are also particularly grateful to the patients, caregivers, 
physicians, nurses, and our scientific and clinical collaborators, whose 
sacrifices, dedication, and perseverance allow us to deliver more good 
days to people living with cancer.

Sincerely,

Mark J. Enyedy

UNITED STATES 
SECURITIES AND EXCHANGE COMMISSION 
Washington, D.C. 20549 
Form 10-K 
ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES 
EXCHANGE ACT OF 1934 

For the year ended December 31, 2020 

OR 

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES 
EXCHANGE ACT OF 1934 

(cid:1409) 

(cid:1407) 

For the 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) 

(Registrant’s telephone number, including area code) 

(781) 895-0600 

Title of Each Class 
Common Stock, $.01 par value 

Securities registered pursuant to Section 12(b) of the Act: 
Trading Symbol(s) 
IMGN 

Name of Each Exchange on Which Registered 
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:1409) Yes   (cid:1407) 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:1407) Yes   (cid:1409) 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:1409) Yes   (cid:1407) No 

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted 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 such files). (cid:1409) Yes   (cid:1407) No 

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting 

company, or an emerging growth company. See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and 
“emerging growth company” in Rule 12b-2 of the Exchange Act.: 

Large accelerated filer (cid:1409) 
Non-accelerated filer (cid:1407) 

Accelerated filer (cid:1407) 
Smaller reporting company (cid:1407) 
Emerging growth company (cid:1407) 

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying 

with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  (cid:1407) 

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its 
internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm 
that prepared or issued its audit report.   (cid:1409)   

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). (cid:1407) Yes   (cid:1409) No 

Aggregate market value, based upon the closing sale price of the shares as reported by the Nasdaq Global Select Market, of common stock 

held by non-affiliates at June 30, 2020: $799,032,429 (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 
February 18, 2021: 199,731,834 shares. 

Portions of the definitive Proxy Statement on Schedule 14A to be delivered to shareholders in connection with the Annual Meeting of 

Shareholders to be held on June 16, 2021 are incorporated by reference into Part III of this report. 

DOCUMENTS INCORPORATED BY REFERENCE 

 
 
 
 
 
 
     
 
 
 
 
 
ImmunoGen, Inc. 

Form 10-K 

TABLE OF CONTENTS 

Part I 

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

Item 

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

5. 

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

Part II 

6. 
7. 
7A. 
8. 
9. 
9A. 
9B. 

10. 
11. 
12. 
13. 
14. 

15. 
16. 

of Equity Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
  Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
  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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  

  Exhibits, Financial Statement Schedules  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
  Form 10-K Summary  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
  Signatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  

Part IV 

Page 
Number 

3
20
34
34
34
36

36
37
37
45
46
78
78
80

80
80
80
80
80

80
84
85

2 

     
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Incorporation of certain information by reference 

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

referred to in this document as “we,” “our,” “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 December 31, 2020 unless 
otherwise indicated. For a description of the risk factors affecting or applicable to our business, see “Risk Factors” 
below. 

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 prospects, future developments, 
product candidates, 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 report. 

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 report. Except as required by law, 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 1.    Business 

PART I 

We are a clinical-stage biotechnology company focused on developing the next generation of antibody-drug 

conjugates (ADCs) to improve outcomes for cancer patients. By generating targeted therapies with enhanced anti-tumor 
activity and favorable tolerability profiles, we aim to disrupt the progression of cancer and offer patients more good 
days. We call this our commitment to ‘‘target a better now.’’ 

An ADC with our proprietary technology comprises an antibody that binds to a target found on tumor cells and 
is conjugated to one of our potent anti-cancer agents as a ‘‘payload’’ to kill the tumor cell once the ADC has bound to its 
target. ADCs are an expanding approach to the treatment of cancer, with nine approved products and the number of 
agents in development growing significantly in recent years. 

We have established a leadership position in ADCs with a portfolio of differentiated product candidates to 

address both solid tumors and hematological malignancies. 

Managing the Impact of the COVID-19 Pandemic 

Since the first quarter of 2020, we have continued to move our clinical studies forward while adapting to meet 
the evolving challenges of the COVID-19 pandemic. We implemented business continuity plans in March 2020, which 
allowed our organization to effectively transition to working from home. Since then, we have worked closely with our 
external partners to monitor progress across our studies and to respond to new developments as they arise. From a 
manufacturing and supply chain perspective, we entered the pandemic with ample drug product and believe we have 
sufficient inventory on hand for all of our ongoing mirvetuximab soravtansine (mirvetuximab) monotherapy and 
combination trials, ongoing IMGN632 studies, and the Phase 1 study for IMGC936. Furthermore, our supply partners 
have taken prospective measures that we believe will ensure our currently activated study sites have sufficient safety 
stock of drug product to weather disruptions in transportation or supply. In addition, from a regulatory perspective, since 
the beginning of the pandemic, we have received timely reviews of our submissions to the U.S. Food and Drug 
Administration (FDA) and other health authorities covering our clinical trial applications.  

We have maintained a high level of productivity since March 2020, when our workforce started working 
remotely, and are actively monitoring trial progress on a global scale. As disclosed in mid-2020, the impact of COVID-19 
slowed site activation and patient enrollment for SORAYA, our single-arm clinical trial to support accelerated approval 
of mirvetuximab in folate receptor alpha (FR(cid:302))-high, platinum-resistant ovarian cancer, by six to eight weeks  

3 

from our original estimates. Factoring in this delay and as previously reported, we expect to report top-line data from 
SORAYA in the third quarter of 2021 and anticipate submitting the biologics license application (BLA) for 
mirvetuximab in this setting by the end of 2021.  

Our Business 

Our lead program is mirvetuximab, a first-in-class investigational ADC targeting folate receptor alpha (FR(cid:302)), a 
cell-surface protein overexpressed in a number of epithelial tumors, including ovarian, endometrial, and non-small-cell 
lung cancers. In 2019, FORWARD I, our Phase 3 clinical trial of mirvetuximab in patients with FR(cid:302)-positive, platinum-
resistant ovarian cancer, did not meet its primary endpoint. In post hoc exploratory analyses in the FR(cid:302)-high population 
scored by the PS2+ method, however, mirvetuximab was associated with longer progression free survival, a higher 
overall response rate, and longer overall survival. 

Following consultation with the FDA, we moved forward with two new trials of mirvetuximab in FR(cid:302)-high, 

platinum-resistant ovarian cancer: SORAYA, a single-arm clinical trial that, if successful, could lead to accelerated 
approval in this setting; and MIRASOL, a randomized Phase 3 clinical trial that, if successful, could lead to full approval 
in this setting. We are actively enrolling both studies and expect to report top-line data from SORAYA in the third 
quarter of 2021 and top-line data from MIRASOL in the first half of 2022. If SORAYA is successful, we expect to 
submit an application for accelerated approval of mirvetuximab in the applicable patient population to the FDA by the 
end of 2021 and, thereafter, seek full approval on the basis of the confirmatory Phase 3 MIRASOL trial. 

Beyond our anticipated monotherapy indications, we are generating data for mirvetuximab in combination with 
other agents to expand into earlier lines of ovarian cancer therapy. To this end, we published data at the virtual American 
Society of Clinical Oncology (ASCO) 2020 annual meeting and the European Society for Medical Oncology (ESMO) 
2020 Congress showing encouraging anti-tumor activity and favorable tolerability profiles for mirvetuximab as a doublet 
with bevacizumab and as a triplet with carboplatin and bevacizumab. In addition, we plan to support the initiation in 
2021 of two investigator-sponsored trials of mirvetuximab plus carboplatin, including a randomized Phase 2 study in 
recurrent platinum-sensitive ovarian cancer and a neo-adjuvant study. With the benefit of these data, we believe there is 
potential for compendia listings for combination use of mirvetuximab and are also working to define the best path 
forward to label expansion.  

As part of our ongoing development efforts, we have generated a new class of cytotoxic payloads that we refer 
to as IGNs. Our IGNs are designed to alkylate DNA without cross-linking, which has provided a broad therapeutic index 
in preclinical models. Specifically, IGN payloads have retained the anti-tumor potency of cross-linking drugs with less 
toxicity to normal cells in in vitro and animal models. These properties have allowed for repeat administration of ADCs 
with IGN payloads in clinical studies, and as supported by preclinical data, suggest that ADCs with IGN payloads may 
be able to be added to other agents in combination regimens. 

IMGN632 is an ADC comprised of a high-affinity antibody designed to target CD123 with site-specific 

conjugation to our most potent IGN payload. We are advancing IMGN632 in clinical trials for patients with blastic 
plasmacytoid dendritic cell neoplasm (BPDCN) and acute myeloid leukemia (AML).  

In October 2020, we announced that the FDA granted Breakthrough Therapy designation for IMGN632 for the 
treatment of patients with relapsed or refractory BPDCN. In conjunction with a Type B meeting in the fourth quarter of 
2020, we aligned with the FDA on a path to full approval in BPDCN, with an amendment to our ongoing 801 Phase 1/2 
study to add a new cohort of up to 20 frontline patients. We expect to complete enrollment and generate top-line data in 
12 to 18 months, with potential BLA submission in 2022.  

We presented data from our Phase 1 clinical trial of IMGN632 in patients with relapsed or refractory BPDCN at 

the Annual Meeting of the American Society of Hematology (ASH) in December of 2020. These data demonstrated an 
overall response rate of 29 percent in all relapsed/refractory patients, including 2 complete responses (CR), 2 clinical 
complete responses (CRc), as well as 1 complete remission with incomplete hematologic recovery (CRi), and 3 partial 
responses (PR). In addition, IMGN632 had a favorable safety profile without any evidence of capillary leak syndrome, 
drug-related discontinuations, or drug-related deaths, with a zero percent 30-day mortality rate.  

Our partners at MD Anderson Cancer Center also presented a poster at ASH detailing preclinical data on 

IMGN632 in combination with azacitidine and venetoclax in relapsed or refractory AML models. The preclinical triplet 
data demonstrated synergistic cell death in AML cell lines and significantly improved survival in AML patient-derived 
xenograft, or PDX models, compared with the azacitidine and venetoclax doublet or IMGN632 monotherapy. In all PDX 
models tested, the triplet combination showed superior anti-leukemic efficacy. In models refractory to the doublet of 
azacitidine and venetoclax, triplet therapy demonstrated the potential to overcome azacitidine and venetoclax resistance. 

4 

These data further support the addition of a CD123-targeted ADC with a novel DNA-damaging payload to the standard 
of care in relapsed or refractory AML.   

Our 802 study, which is a Phase 1b/2 study designed to determine the safety, tolerability, and preliminary 

antileukemia activity of IMGN632 when administered in combination with azacitidine and/or venetoclax to patients with 
relapsed and frontline CD123-positive AML, is in the dose-escalation phase, enrolling relapsed and refractory patients to 
determine the recommended Phase 2 dose of IMGN632 for combination regimens. We anticipate sharing data from this 
study in 2021. 

We continue to advance additional pipeline programs. IMGC936 is an ADC in co-development with 
MacroGenics designed to target ADAM9, an enzyme overexpressed in a range of solid tumors and implicated in tumor 
progression and metastasis. IMGC936 incorporates a number of innovations, including antibody engineering to extend 
the half-life, site-specific conjugation with a fixed drug-antibody ratio to enable higher dosing, and a next-generation 
linker and payload for improved stability and bystander activity. The Investigational New Drug application (IND) for 
IMGC936 was accepted by the FDA in the second quarter of 2020, and we began enrollment in the Phase 1 study in the 
fourth quarter of 2020. 

IMGN151 is our next generation anti-FR(cid:302) candidate in preclinical development. This ADC integrates 
innovation in each of its components, which may enable IMGN151 to address patient populations with lower levels of 
FR(cid:302) expression, including tumor types outside of ovarian cancer. We presented encouraging data for IMGN151 at the 
American Academy of Cancer Research Virtual Annual Meeting II in June 2020. We expect to file the IND for 
IMGN151 by the end of 2021. 

Collaborations and Out-Licenses   

Over the last 39 years, ImmunoGen has assembled the most comprehensive ‘‘toolbox’’ in the ADC field. Our 

platform technology combines advanced chemistry and biochemistry with innovative approaches to antibody 
optimization, with a focus on increasing the diversity and potency of our payload agents, advancing antibody-payload 
linkage and release technologies, and integration of novel approaches to antibody engineering. These capabilities have 
enabled us to generate a pipeline of novel candidates with potent anti-tumor activity and favorable safety profiles that we 
can develop as monotherapies and in combination with existing and novel therapies. 

Collaborating on ADC development with other companies allows us to generate revenue, mitigate expenses, 

enhance our capabilities, and extend the reach of our proprietary platform. The most advanced partner program is 
Roche’s marketed product, Kadcyla® (ado-trastuzumab emtansine). Our ADC technology is also used in candidates in 
clinical development with a number of partners. We have evolved our partnering approach to pursue relationships where 
we can gain access to technology and complementary capabilities, such as our technology swap with CytomX 
Therapeutics, Inc. (CytomX), as well as co-development and co-commercialization arrangements, such as our 
relationship with MacroGenics. 

We have selectively licensed restricted access to our ADC platform technology to other companies to expand 

the use of our technology and to provide us with cash to fund our own product programs. These agreements typically 
provide the licensee with rights to use our ADC platform 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.   

Below is a table setting forth our current licensed ADC partnerships and status of the most advanced program in 

each partnership:  

5 

Partner 

Roche 

Huadong 

CytomX 

Debiopharm 

Bayer 

Novartis 

    Licensed targets/compounds 

    Status of Most Advanced Program 

  HER2, 4 other1 

  Mirvetuximab – Greater China 

  CD166, EpCAM 

  CD372 

  Mesothelin 

  Marketed 

  Phase 3 

  Phase 2 

  Phase 2 

  Phase 1 

  cKit, pCadherin, CDH6, CCR7, 1 other1 

  Phase 1 

Oxford 
BioTherapeutics/Menarini 

  CD2053 

  Undisclosed 

Fusion 

Viridian 

1 Undisclosed. 

  IGF-1R non-cancer radiopharmaceuticals 

  Pre-clinical 

  Phase 1 

  Phase 1 

2 Debiopharm has an exclusive license for Debio 1562 (formerly known as IMGN529). 

3 Oxford BioTherapeutics and Menarini are developing MEN 1309, an ADC targeting CD205 and utilizing our DM4 
payload, pursuant to a sublicense from Amgen, which in turn licensed our maytansinoid ADC technology to develop and 
commercialize ADCs targeting CD205. 

Below is a brief description of the business relationships underlying each of the foregoing programs. For more 

information concerning these relationships, including their ongoing financial and accounting impact on our business, 
please read Note C, Significant Collaborative Agreements, to our consolidated financial statements included in this 
report. 

Roche 

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

to use our maytansinoid technology with antibodies that target HER2. Roche’s Kadcyla resulted from this license. 
Kadcyla was approved for marketing in the U.S., EU, and Japan in 2013. We are entitled to receive up to a total of 
$44 million in milestone payments, of which we have received $39 million to date, and also tiered royalties on the 
commercial sales of Kadcyla or any other resulting products as described below. Roche is responsible for the 
development, manufacturing, and marketing of any products resulting from this license. 

In 2015, Immunity Royalty Holdings, L.P. (IRH) paid us $200 million to purchase our right to receive 100% of 
the royalty payments on commercial sales of Kadcyla arising under our development and commercialization license with 
Genentech, until IRH had received aggregate Kadcyla royalties equal to $235 million or $260 million, depending on 
when the aggregate Kadcyla royalties received by IRH reached a specified milestone. Once the applicable threshold 
would have been met, if ever, we would thereafter have received 85% and IRH would have received 15% of the Kadcyla 
royalties for the remaining royalty term. In January 2019, we sold our residual rights to receive royalty payments on 
commercial sales of Kadcyla to OMERS, the defined benefit pension plan for municipal employees in the Province 
of Ontario, Canada, for $65.2 million, net of fees. Simultaneously, OMERS purchased IRH’s right to the royalties we 
previously sold to IRH as described above, therefore obtaining the rights to 100% of the royalties received from that date 
on. 

We also granted Roche, through its Genentech unit, exclusive development and commercialization licenses to 

use our maytansinoid ADC technology with antibodies to four specified targets, which were granted under the terms of a 
separate, now expired 2000 right-to-test agreement with Genentech. For each of these licenses, we are entitled to receive 
up to a total of $38 million in milestone payments and also royalties on the sales of any resulting products. Roche is 
responsible for the development, manufacturing, and marketing of any products resulting from these licenses. The 
standard termination provisions discussed below apply to these licenses. 

Huadong 

In October 2020, we entered into a collaboration and license agreement with Hangzhou Zhongmei Huadong 

Pharmaceutical Co., Ltd. (Huadong) a subsidiary of Huadong Medicine Co., Ltd., under which Huadong will exclusively 
develop and commercialize mirvetuximab in the People’s Republic of China, Hong Kong, Macau, and Taiwan, which 

6 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
we refer to as Greater China. Under the terms of the collaboration and license agreement, we received a non-refundable 
upfront payment of $40.0 million and are eligible to receive additional payments of up to $265.0 million as certain 
development, regulatory, and net sales milestones are achieved. We are also eligible to receive tiered low double digit to 
high teen royalties as a percentage of mirvetuximab commercial sales by Huadong in Greater China. Huadong is 
responsible for the development and commercialization of mirvetuximab in Greater China except in limited 
circumstances. In addition, we granted Huadong a right of first negotiation if in the future we determine to enter into an 
agreement to grant a third party rights in Greater China to develop or commercialize a product, other than mirvetuximab, 
that specifically binds to FR(cid:302). We retain all rights to mirvetuximab in the rest of the world.  

CytomX 

In 2016, we granted CytomX an exclusive development and commercialization license to our maytansinoid and 

IGN ADC technology for use with Probodies™ that target CD166 under a now-expired reciprocal right-to-test 
agreement. We are entitled to receive up to a total of $160 million in milestone payments plus royalties on the 
commercial sales of any resulting product. CytomX is responsible for the manufacturing, product development, and 
marketing of any products resulting from this license. The standard termination provisions discussed below apply to this 
license.  

In 2017, we took exclusive development and commercialization licenses to CytomX’s proprietary Probody 

technology for use with Probodies that target two specified targets under the same reciprocal right-to-test agreement. We 
terminated one of these licenses for convenience prior to the end of 2017. We terminated the second license in 
December 2019 in connection with the grant of the EpCAM license to CytomX discussed below. 

In December 2019, we granted CytomX an exclusive development and commercialization license to our 

maytansinoid and IGN ADC technology for use with antibodies (and Probodies™ developed therefrom) that target 
EpCAM. In January 2020, we received a $7.5 million upfront license payment and are entitled to receive up to a total of 
$355 million in milestone payments plus royalties on the commercial sales of any resulting product. CytomX is 
responsible for the manufacturing, product development, and marketing of any products resulting from this license. The 
standard termination provisions discussed below apply to this license. 

Debiopharm 

 In May 2017, we entered into an Exclusive License and Asset Purchase Agreement with Debiopharm 

International, S.A., pursuant to which Debiopharm acquired our antibody-drug conjugate IMGN529, a potential new 
treatment for patients with CD37-positive B-cell malignancies, such as non-Hodgkin lymphoma (NHL). The transaction 
included the sale to Debiopharm of specified intellectual property and other assets related to the IMGN529 program and 
an exclusive license to additional intellectual property necessary or useful for Debiopharm to develop and commercialize 
IMGN529 (now known as Debio 1562). 

Under the terms of the agreement, we received a $25 million upfront payment for the IMGN529 program and a 
$5 million milestone payment following the transfer of technology relating to IMGN529 to Debiopharm. In addition, we 
are entitled to a $25 million milestone payment upon IMGN529/Debio 1562 entering a Phase 3 clinical trial. Except for 
the foregoing upfront and milestone payments, we will not be entitled to receive any additional milestone payments or 
royalties under the agreement. The standard termination provisions discussed below apply to this license. 

Bayer  

In 2008, we granted Bayer an exclusive development and commercialization license to use our maytansinoid 
ADC technology with antibodies or other proteins that target mesothelin. We are entitled to receive, for each product 
developed and marketed by Bayer 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 is responsible for the development, manufacturing, 
and marketing of any products resulting from this license.  The standard termination provisions discussed below apply to 
this license. 

Novartis 

We granted Novartis exclusive development and commercialization licenses to our maytansinoid and IGN ADC 

technology for use with antibodies to six specified targets under a now-expired right-to-test agreement established in 
2010. In May 2018, Novartis terminated one of its six development and commercialization licenses. With respect to each 
remaining license, we are entitled to receive up to a total of $199.5 million in milestone payments, plus royalties on the 
commercial sales of any resulting products. Novartis is responsible for the manufacturing, product development, and 
marketing of any products resulting from this agreement. The standard termination provisions discussed below apply to 
these licenses. 

7 

Oxford BioTherapeutics/Menarini 

In 2013, we granted Amgen an exclusive development and commercialization license to our maytansinoid ADC 

technology for use with antibodies that target CD205 under a now-expired right-to-test agreement, which Amgen 
sublicensed to Oxford BioTherapeutics, which is developing MEN 1309 with Menarini. With respect to this license, we 
are entitled to receive up to a total of $34 million in milestone payments, plus royalties on the commercial sales of any 
resulting products. Amgen (or its sublicensee(s)) is responsible for the manufacturing, product development, and 
marketing of any products resulting from this development and commercialization license. The standard termination 
provisions discussed below apply to this license. 

Fusion 

In December 2016, we entered into an exclusive license agreement to a specified target with Fusion 
Pharmaceuticals Inc. We are entitled to receive up to a total of $50 million in milestone payments plus royalties on the 
commercial sales of any resulting products. Fusion is responsible for the manufacturing, development, and marketing of 
any products resulting from the license. The standard termination provisions discussed below apply to this license. 

Viridian  

In October 2020, we entered into a license agreement with Viridian Therapeutics, Inc. pursuant to which we 
granted Viridian the exclusive right to develop and commercialize an insulin-like growth factor-1 receptor (IGF-1R) 
antibody for all non-oncology indications that do not use radiopharmaceuticals in exchange for an upfront payment, with 
the potential to receive up to a total of $143.0 million in milestone payments plus royalties on the commercial sales of 
any resulting product. Viridian is responsible for the manufacturing, development, and marketing of any products 
resulting from the license agreement. The standard termination provisions discussed below apply to this license. 

Standard Termination Provisions 

Standard termination provisions in our license agreements state that the partner 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 certain of these agreements 
upon the occurrence of specified events. Upon termination, the partner’s rights to our intellectual property with respect 
to the applicable target are canceled and could then be used by us or re-licensed for that target. Unless earlier terminated, 
the agreement will continue in effect until the expiration of partner’s royalty obligations, which are determined on a 
product-by-product and country-by-country basis. For each product and country, 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. 

Other Agreements 

From time to time we have entered into additional agreements with some of our collaborators pursuant to which 

we have provided certain Chemistry, Manufacturing and Controls (CMC)-related development and pre-pivotal ADC 
manufacturing services, or supplied ADC payloads, with respect to products they are developing under their licenses 
with us, with respect to which we have been entitled to receive payments at mutually negotiated rates. 

Patents, Trademarks and Trade Secrets 

ImmunoGen has a substantial and robust intellectual property portfolio comprising more than 1,400 issued 
patents and over 600 pending patent applications on a worldwide basis. Our intellectual property strategy centers on 
obtaining high quality patent protection directed to various embodiments of our proprietary technologies and product 
candidates. Using this strategy, our ADC technology and our product candidates are protected through a multi-layered 
approach. In this regard, we have patents and patent applications covering antibodies and other cell binding agents, 
linkers, cytotoxic payload agents (e.g., tubulin-acting maytansinoids, DNA-alkylating IGNs, and DNA-acting 
camptothecins), conjugation methodologies and complete ADCs, comprising one or more of these components, as well 
as methods of making and using each of the above. Typically, multiple issued patents and pending patent applications 
cover various embodiments of each of ImmunoGen’s and our licensees’ product candidates. 

We consider our tubulin-acting maytansinoid, DNA-alkylating IGN, and DNA-acting camptothecin cytotoxic 

payload agent technologies to be key components of our overall patent strategy. With regard to our tubulin-acting 
maytansinoid cytotoxic payload agents, we currently own 20 issued U.S. patents covering various embodiments of our 
maytansinoid technology including those with claims directed to certain maytansinoids, including DM4 and DM21, and 
methods of manufacturing of  DM1, DM4, and DM21, as well as methods of using the same. These issued patents 

8 

remain in force until various times between 2022 and 2038. With regard to our IGN payload agents, we have 28 issued 
U.S. patents covering various aspects of our DNA-acting cytotoxic payload agents, which will expire at various times 
between 2030 and 2040. With regard to our camptothecin agents, we have a pending U.S. patent application covering 
various aspects of our camptothecin cytotoxic payload agents, which will expire in 2040. In all cases, we have received 
or are applying for comparable patent protection in other major commercial and manufacturing jurisdictions, including 
Europe, Japan, and China. In nearly all cases for our maytansinoid, IGN, and camptothecin patent portfolios, we have 
additional pending patent applications disclosing and claiming many other related and strategically important 
embodiments of these technologies which, upon issuance or grant, will extend our patent protection term over these 
technologies by several additional years. 

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 21 issued patents related to many of our linker technologies, as well as additional pending patent applications 
disclosing and claiming many other related and strategically important embodiments of these linker technologies, 
including methods of making the linkers and antibody maytansinoid conjugates comprising these linkers. These issued 
patents remain in force until various times between 2023 and 2034. We also have 17 issued U.S. patents covering 
methods of assembling ADCs from their constituent antibody, linker, and cytotoxic payload agent moieties. These issued 
patents will expire between 2026 and 2040. In nearly all instances for both our linker and conjugation patent portfolios, 
we have additional pending patent applications disclosing and claiming many other related and strategically important 
embodiments of these technologies which, upon issuance or grant, will extend our patent protection term over these 
technologies by several additional years. In all cases, we have received or are applying for comparable patents in other 
major commercial and manufacturing jurisdictions including Europe, Japan, and China.   

We also file, prosecute, and maintain a substantial portfolio of patents and patent applications specifically 

directed to ImmunoGen’s and our licensees’ ADC candidates. In this regard, we craft a detailed patent protection 
strategy for each ADC as it approaches clinical evaluation. Such strategies make use of the patents and patent 
applications described in the preceding paragraphs, as well as ADC-specific filings, to create a multi-layered and multi-
jurisdictional patent protection approach for each ADC as it enters the clinic. In addition to the platform patent strategy 
described above and specific to mirvetuximab, we have 18 issued U.S. patents and 11 pending U.S. applications 
covering various embodiments of the composition of matter and methods of treatment using mirvetuximab, expiring at 
various times between 2031 and 2038. These ADC-specific patent strategies are intended to provide the exclusivity basis 
for revenue and royalties arising from commercial development of each of ImmunoGen’s and our licensees’ ADCs. 

We expect our continued independent and collaborative work in each of these areas will lead to other patent 

applications. We will be the owner of all patents covering our independently generated inventions. In all other instances, 
we expect to either be the sole owner or co-owner of any patents covering collaboratively generated inventions insofar as 
they relate to co-developed products or our ADC platform technology, or otherwise have an exclusive or non-exclusive 
license to the technology covered by such patents. 

We cannot provide assurance that pending 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. 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. 

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, Astellas, 

9 

AstraZeneca/MedImmune, Daiichi Sankyo, GlaxoSmithKline, and AbbVie have programs to attach a 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, sales, 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: 

• 

• 

• 

• 

the safety, efficacy, and convenience of products; 

the timing of regulatory approvals and commercial introductions; 

special regulatory designation of products, such as orphan drug and breakthrough therapy designations; and 

the effectiveness of marketing, sales, and reimbursement efforts. 

Our competitive position depends on a combination of factors. These include effectively pursuing the 
development of proprietary products, the implementation of clinical development programs, the ability to appropriately 
manufacture, sell, and market our products, and obtain patent protection for our products. In addition, we must secure 
sufficient capital resources to accomplish all of the previously mentioned activities.    

Continued 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 (FDCA) and in the case 
of biologics, also under the Public Health Service Act (PHSA) and implementing regulations. The process of obtaining 
regulatory approvals and the subsequent compliance with applicable federal, state, and local statutes and regulations 
require the expenditure of substantial time and financial resources. Failure to comply with the applicable U.S. 
requirements at any time during the product development process, approval process, or after approval, may subject an 
applicant to adverse administrative or judicial actions. These actions 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 such administrative or judicial 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: 

• 

• 

• 

completion of preclinical and other nonclinical laboratory tests, animal studies, and formulation studies 
according to current Good Laboratory Practices (cGLP) or other applicable regulations; 

submission to the FDA of an IND, which must become effective before human clinical trials may begin; 

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; 

10 

• 

• 

• 

development and approval of a companion diagnostic if the FDA or the sponsor believes that its use is 
essential for the safe and effective use of a corresponding product; 

submission to the FDA of an NDA or BLA; 

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 

•  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 clinical 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 nonclinical testing may continue 
even after the IND is submitted and clinical trials have begun. 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 about ongoing 
or proposed clinical trials or non-compliance with specific FDA requirements, and the trials may not begin or continue 
until the sponsor submits additional information that alleviates FDA concerns and the FDA notifies the sponsor that the 
hold has been lifted. 

Each clinical trial must be conducted under the supervision of one or more qualified investigators in accordance 

with cGCP requirements in accordance with a protocol for each phase of the clinical trial included as part of the IND, 
and timely safety reports must be submitted to the FDA and the investigators for serious and unexpected adverse events. 
A local or central institutional review board (IRB) acting on behalf of 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. 

Human clinical trials are typically conducted in three sequential phases that may overlap or be combined: 
•  Phase I:  The product candidate is initially introduced into healthy human subjects and tested for safety 

and 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. 
•  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. 

•  Phase III:  These trials are undertaken to further evaluate dosage, clinical efficacy, and safety in an 

expanded patient population at geographically dispersed clinical study sites and to establish the overall 
risk-benefit ratio of the product candidate and provide, if appropriate, an adequate basis for product 
labeling. 

Post-approval trials, sometimes referred to as Phase IV, may be conducted after initial marketing approval. 

These trials are used to gain additional information about the use of the approved drug in the treatment of patients in the 
intended therapeutic indication. In certain instances, the FDA may mandate the performance of Phase IV clinical trials as 
a condition of approval of an NDA or BLA. 

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 or serious patient reactions. Additionally, some 
clinical trials are overseen by an independent group of qualified experts organized by the sponsor, known as a data safety 
monitoring board or committee. Depending on its charter, this group may determine whether a trial may move forward at 

11 

designated check points based on access to certain data from the trial. 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 may request meetings with the FDA. These meetings often 
occur prior to submission of an IND, at the end of Phase II, and before an NDA or BLA is submitted, but 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 the 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 or trials that they believe will support approval of the new drug.  

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 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. 

While the IND is active, progress reports summarizing the results of the clinical trials and nonclinical studies 
performed since the last progress report must be submitted at least annually to the FDA, and written IND safety reports 
must be submitted to the FDA and investigators for serious and unexpected suspected adverse events, findings from 
other studies suggesting a significant risk to humans exposed to the same or similar drugs, findings from animal or in 
vitro testing suggesting a significant risk to humans, and any clinically important increased incidence of a serious 
suspected adverse reaction compared to that listed in the protocol or investigator brochure. 

There are also requirements governing the reporting of ongoing clinical trials and completed trial results to 

public registries. Most sponsors of clinical trials of FDA-regulated products are required to register and disclose 
specified clinical trial information, which is publicly available at www.clinicaltrials.gov. Information related to the 
product, patient population, phase of investigation, trial sites and investigators, and other aspects of the clinical trial is 
then made public as part of the registration. Sponsors are also obligated to discuss the results of their clinical trials after 
completion. Disclosure of the results of these trials can be delayed until the new product or new indication being studied 
has been approved. However, there are evolving rules and increasing requirements for publication of all trial-related 
information, and it is possible that data and other information from trials involving drugs that never garner approval 
could require disclosure in the future. 

Companion Diagnostics 

For some of our product candidates, including mirvetuximab and potentially others, we plan to work with 

collaborators to develop or obtain access to in vitro companion or complementary diagnostic tests to identify appropriate 
patients for these targeted therapies. 

If a sponsor or the FDA believes that a diagnostic test is essential for the safe and effective use of a 
corresponding therapeutic product, a sponsor will typically work with a collaborator to develop an in vitro diagnostic 
(IVD). Companion diagnostics can be used to identify patients likely to be more responsive to a particular therapy or at 
increased risk for serious side effects as a result of treatment with a particular therapeutic product. They may also be 
useful for monitoring the response to treatment for the purpose of adjusting treatment or doses to achieve improved 
safety or effectiveness. 

IVDs are regulated by the FDA as medical devices, and it issued a final guidance document in 2014, entitled, 

“In Vitro Companion Diagnostic Devices” that is intended to assist companies developing in vitro companion diagnostic 
devices and companies developing therapeutic products that depend on the use of a specific in vitro companion 
diagnostic for the safe and effective use of the product. The FDA defined an IVD companion diagnostic device as a 
device that provides information that is essential for the safe and effective use of a corresponding therapeutic product. 
The FDA also noted that in some cases, if evidence is sufficient to conclude that the IVD companion diagnostic device is 
appropriate for use with a class of therapeutic products, the intended use/indications for use should name the therapeutic 
class, rather than each specific product within the class. 

In April 2020, the FDA published a final guidance entitled, “Developing and Labeling In Vitro Companion 

Diagnostic Devices for a Specific Group or Class of Oncology Therapeutic Products” that expands on that last issue and 
describes considerations for the development and labeling of in vitro companion diagnostic devices to support the 
indicated uses of multiple drug or biological oncology products, when appropriate.  

12 

The FDA also issued a draft guidance in July 2016, entitled, “Principles for Codevelopment of an In Vitro 

Companion Diagnostic Device with a Therapeutic Product” to serve as a practical guide to assist therapeutic product 
sponsors and IVD sponsors in developing a therapeutic product and an accompanying IVD companion diagnostic. 

The FDA subsequently introduced the concept of complementary diagnostics that are distinct from companion 
diagnostics because they provide additional information about how a drug is used or identify patients who are likely to 
derive the greatest benefit from therapy without being required for the safe and effective use of that drug. The FDA has 
not yet provided much guidance on the regulation and use of complementary diagnostics, but several have been 
approved. 

The FDA indicated that it will apply a risk-based approach to determine the regulatory pathway for IVD 

companion and complementary diagnostic devices, as it does with all medical devices. This means that the regulatory 
pathway will depend on the level of risk to patients, based on the intended use of the IVD companion diagnostic device 
and the controls necessary to provide a reasonable assurance of safety and effectiveness. The two primary types of 
marketing pathways for medical devices are clearance of a premarket notification under Section 510(k) of the Federal 
Food, Drug, and Cosmetic Act, or 510(k), and approval of a premarket approval application (PMA). We expect that any 
IVD companion diagnostic device developed for use with our drug candidates will utilize the PMA pathway and that a 
clinical trial performed under an investigational device exemption, or IDE, will have to be completed before the PMA 
may be submitted. 

The FDA expects that the therapeutic sponsor will address the need for an IVD companion diagnostic device in 

its therapeutic product development plan and that, in most cases, the therapeutic product and its corresponding IVD 
companion diagnostic device will be developed contemporaneously. If the companion diagnostic test will be used to 
make critical treatment decisions such as patient selection, treatment assignment, or treatment arm, it will likely be 
considered a significant risk device for which a clinical trial will be required. 

The sponsor of the IVD companion diagnostic device will be required to comply with the FDA’s IDE 

requirements that apply to clinical trials of significant risk devices. If the diagnostic test and the therapeutic drug are 
studied together to support their respective approvals, the clinical trial must meet both the IDE and IND requirements. 

PMAs must be supported by valid scientific evidence, which typically requires extensive data, including 

technical, preclinical, clinical, and manufacturing data, to demonstrate to the FDA’s satisfaction the safety and 
effectiveness of the device. For diagnostic tests, a PMA typically includes data regarding analytical and clinical 
validation studies. As part of its review of the PMA, the FDA will conduct a pre-approval inspection of the 
manufacturing facility or facilities to ensure compliance with the Quality System Regulation (QSR) which requires 
manufacturers to follow design, testing, control, documentation, and other quality assurance procedures. FDA review of 
an initial PMA may require several years to complete. 

After approval, the use of an IVD companion diagnostic device with a therapeutic product will be stipulated in 

the instructions for use in the labeling of both the diagnostic device and the corresponding therapeutic product. In 
addition, a diagnostic test that was approved through the PMA process or one that was cleared through the 
510(k) process and placed on the market will be subject to many of the same regulatory requirements that apply to 
approved drugs. 

U.S. Review and Approval Processes 

The results of product development, preclinical and other non-clinical 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 are 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 

13 

interpret data differently than we interpret the same data. 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 Phase IV clinical trials. Priority review and accelerated approval do not 
change the standards for approval but may expedite the approval process. 

After the FDA evaluates an NDA or BLA, it will issue an approval letter or a Complete Response Letter. An 

approval letter authorizes commercial marketing of the drug with prescribing information for specific indications. A 
Complete Response Letter indicates that the review cycle of the application is complete, and the application will not be 
approved in its present form. A Complete Response Letter usually describes the specific deficiencies in the NDA or 
BLA identified by the FDA and may require additional clinical data, such as an additional Phase III trial or other 
significant and time-consuming requirements related to clinical trials, nonclinical studies, or manufacturing. If a 
Complete Response Letter is issued, the sponsor must resubmit the NDA or BLA, addressing all of the deficiencies 
identified in the letter, or withdraw the application. Even if such data and information are submitted, the FDA may 
decide that the NDA or BLA does not satisfy the criteria for approval. 

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 a sponsor to conduct Phase IV testing which involves clinical trials designed to further 
assess a drug’s safety and effectiveness after NDA or BLA approval and may require testing and surveillance programs 
to monitor the safety of approved products which have been commercialized. The FDA may also place other conditions 
on approval including the requirement for a risk evaluation and mitigation strategy (REMS) to assure the safe use of the 
drug. If the FDA concludes a REMS is needed, the sponsor of the NDA or BLA must submit a proposed REMS. The 
FDA will not approve the NDA or BLA without an approved REMS, if required. A REMS could include medication 
guides, physician communication plans, or other elements to assure safe use, such as restricted distribution methods, 
patient registries, and other risk minimization tools. Any of these limitations on approval or marketing could restrict the 
commercial promotion, distribution, prescription, or dispensing of products. Marketing approval may be withdrawn for 
non-compliance with regulatory requirements or if problems occur following initial marketing. 

The Pediatric Research Equity Act (PREA) requires a sponsor to conduct pediatric clinical trials for most drugs 

and biologics, 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 need to be collected before the pediatric clinical trials begin. 
Orphan indications are exempt from PREA. 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 

14 

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 U.S. 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. Under the Best Pharmaceuticals for 

Children Act (BPCA) an additional six months of marketing exclusivity may be available if a sponsor conducts clinical 
trials in children in response to a written request from the FDA (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 

The Patient Protection and Affordable Care Act, which included the Biologics Price Competition and 

Innovation Act of 2009 (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 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 meets additional requirements 
that show, among other things, that the product will produce the same clinical result as the reference product in any 
given patient. In addition, for products administered to a patient more than once, the effects of switching back and forth 
between the interchangeable product and a reference product on safety and efficacy will have to be evaluated. An 
interchangeable product 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. 

The FDA has issued a number of final and draft guidance documents in order to implement the law and will 

likely continue to publish new guidance as new issues relating to biosimilars and interchangeability are identified. The 
guidance documents provide FDA’s current thinking on approaches to demonstrating that a proposed biological product 
is biosimilar to a reference product. Although the FDA intends to issue additional guidance documents in the future, the 
absence of final guidance documents covering all biosimilars issues does not prevent a sponsor from seeking licensure of 
a biosimilar under the BPCIA, as evidenced by the biosimilar products already approved by the FDA. 

 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 

15 

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 exclusivity, except in very limited 
circumstances. The FDA issued a final rule intended to clarify what constitutes some of those limited circumstances. For 
example, 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 continues to periodically provide additional 
clarification, and in July 2018 published a final guidance entitled, “Clarification of Orphan Designation of Drugs and 
Biologics for Pediatric Subpopulations of Common Diseases.”   

Mirvetuximab has been granted orphan drug designation by the FDA in the United States, and orphan medicinal 

product status by the European Medicines Agency (EMA) in the European Union for the treatment of ovarian cancer. 
IMGN632 has been granted orphan drug designation by the FDA for the treatment of AML and BPDCN and by the 
EMA for the treatment of BPDCN. In the U.S., orphan drug designation provides us with seven years of market 
exclusivity that begins once mirvetuximab receives FDA marketing approval for the use for which the orphan drug status 
was granted. In the EU, orphan designation will provide us with ten years of market exclusivity that begins after 
mirvetuximab receives marketing authorization 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; Breakthrough Therapy Designation 

The FDA has various programs, including Fast Track, priority review, and accelerated approval, that 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. If SORAYA is successful, we expect to submit an 
application for accelerated approval of mirvetuximab in the applicable patient population to the FDA by the end of 2021 
and, thereafter, seek full approval on the basis of the confirmatory Phase 3 MIRASOL trial. 

In the Food and Drug Administration Safety and Improvement Act (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 indicates that the drug may demonstrate substantial 
improvement over available therapy on a clinically significant endpoint(s). A sponsor may request Breakthrough 

16 

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. In 
October 2020, we announced that the FDA granted Breakthrough Therapy designation for IMGN632 for the treatment of 
patients with relapsed or refractory BPDCN. 

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, certain 
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 or our partners 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. 
Other Healthcare Laws  

Although we currently do not have any products on the market, we will be subject to additional healthcare 

regulation and enforcement by the federal government and by authorities in the states and other countries in which we 
conduct our business after a product is approved and commercialized. Such laws include, without limitation, state and 
federal anti-kickback, fraud and abuse, false claims, privacy and security, and physician sunshine laws and regulations. 
If our operations are found to be in violation of any of such laws or any other governmental regulations that apply to us, 
we may be subject to penalties, including, without limitation, administrative, civil and criminal penalties, damages, fines, 
disgorgement, the curtailment or restructuring of our operations, exclusion from participation in federal and state 
healthcare programs, and imprisonment, any of which could adversely affect our ability to operate our business and our 
financial results.  

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 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 EMA where it will be evaluated by the Committee for Medicinal Products for Human Use. A 
favorable opinion typically results in the grant by the EMA of a single marketing authorization that is valid for all 

17 

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 EMA, 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 payers include government healthcare programs such as Medicare, managed care providers, private health 
insurers, and other organizations. We anticipate third-party payers will provide reimbursement for our products. 
However, these third-party payers 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 have incorporated certain health outcomes measures in our clinical studies but may need to 
conduct expensive additional 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 payers. 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 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 
for 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 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. 

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, was expected to have a significant impact on the health care 
industry and result in expanded coverage for the uninsured. With regard to pharmaceutical products, among other things, 
ACA was 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 occurred. In addition, during the past four years, Congress and former President 
Trump’s administration took certain actions to attempt to weaken and repeal the ACA, and as a result certain sections of 
the ACA were not fully implemented or effectively repealed; for example, as part of the Tax Cuts and Jobs Act, the U.S. 
Congress eliminated the ACA’s individual mandate. These actions and related judicial challenges and decisions added to 
the uncertainty of the changes enacted as part of ACA. President Biden intends to reverse some of these actions in order 
to expand the provisions of the law and extend health coverage to more Americans. Although the current U.S. Congress 

18 

would likely support President Biden’s efforts, it is not clear what if any effect any newly enacted or reenacted 
provisions of ACA would have, and we also cannot predict the effects of any other new laws or policies that may 
implement other drug pricing reforms. 

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  

During the years ended December 31, 2020, 2019, and 2018, we incurred $114.6 million, $114.5 million, and 

$174.5 million, respectively, in research and development expenses. 

Manufacturing 

We contract with third-party contract manufacturers (CMOs) for the manufacture of our product candidates for 

both our clinical and potential commercial needs. Our CMO network manufactures antibody, linker, and payload, and 
conjugates the foregoing to create bulk drug substance of our product candidates and processes the bulk drug substance 
into vialed and labeled drug product for use in humans. Although we are reliant on third parties to manufacture our 
product candidates, we have personnel with extensive manufacturing experience to oversee the relationships with our 
CMOs. 

CMOs are subject to extensive governmental regulations and we depend on them to manufacture our product 

candidates in accordance with cGMP. We have an established quality assurance program to ensure that the CMOs 
involved in the manufacture of product candidates do so in accordance with cGMP and other applicable U.S. and foreign 
regulations. We believe that our current CMO network complies with such regulations. 

Employees and Human Capital Resources 

As of December 31, 2020, we had 79 full-time employees, of whom 55 were engaged in research and 
development activities. Of the 55 research and development employees, 42 employees hold post-graduate degrees, of 
which 14 hold Ph.D. degrees and 3 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. 

Our key human capital management objectives are to attract, retain, and develop the highest quality talent. To 

support these objectives, our human resources programs are designed to acquire talent to create a high-performing and 
diverse workforce; develop employees to prepare them for critical roles and leadership positions for the future; reward 
and support employees through competitive pay and benefits; and enhance our culture through efforts aimed at making 
the workplace more engaging and inclusive. At ImmunoGen, prejudice, racism, and intolerance are unacceptable. We 
are committed to diversity, equity, and inclusion across all aspects of our organization, including in our hiring, 
promotion, and development practices. 
Corporate Information 

We were organized as a Massachusetts corporation in March 1981. Our principal offices are located at 
830 Winter Street, Waltham, Massachusetts 02451, and our telephone number is (781) 895-0600. Our internet address 
is www.immunogen.com. Our annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on 
Form 8-K, and all amendments to those reports, are available to you free of charge through the “Investors & Media – 
Financials & Filings - SEC Filings” 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. Please note that the information 
contained on the web site is not a part of this annual report on Form 10-K. 

19 

 
Item 1A.    Risk Factors 

INVESTING IN OUR COMMON STOCK INVOLVES A HIGH DEGREE OF RISK. BEFORE DECIDING WHETHER 
TO INVEST IN OUR COMMON STOCK, YOU SHOULD CAREFULLY CONSIDER THE RISKS DESCRIBED BELOW, 
TOGETHER WITH THE OTHER INFORMATION CONTAINED IN THIS ANNUAL REPORT ON FORM 10-K, 
INCLUDING OUR CONSOLIDATED FINANCIAL STATEMENTS AND RELATED NOTES. THE RISKS AND 
UNCERTAINTIES DESCRIBED BELOW ARE THOSE THAT WE CURRENTLY BELIEVE MAY MATERIALLY 
AFFECT OUR COMPANY AND IF ANY OF THESE RISKS ACTUALLY OCCURS, OUR BUSINESS, FINANCIAL 
CONDITION, RESULTS OF OPERATIONS, OR CASH FLOW COULD BE SERIOUSLY HARMED. ADDITIONAL 
RISKS AND UNCERTAINTIES THAT WE ARE UNAWARE OF OR THAT WE CURRENTLY DEEM IMMATERIAL 
ALSO MAY BECOME IMPORTANT FACTORS THAT AFFECT OUR COMPANY AND MAY MATERIALLY IMPAIR 
OUR BUSINESS. 

Risks Related to our Financial Condition 

We have a history of operating losses and expect to incur significant additional operating losses and may never be 
profitable. 

 We have generated operating losses since our inception. As of December 31, 2020, we had an accumulated 

deficit of $1.3 billion. We may never be profitable. We expect to incur substantial additional operating expenses over the 
next several years as our development, preclinical testing, and clinical trials continue. We intend to continue to invest 
significantly in our product candidates. We may encounter technological or regulatory difficulties as part of this 
development and commercialization process that we cannot overcome or remedy. Our revenues to date have been 
primarily from upfront and milestone payments, research and development support, and clinical materials reimbursement 
from our collaborators, and from royalties received from the commercial sales of Kadcyla (which we sold partial cash 
rights to in 2015 and the remainder in 2019). Because of the numerous risks and uncertainties associated with developing 
pharmaceutical drugs, we are unable to predict the extent of any future losses or when we will become profitable, if at 
all. In addition, our expenses could increase beyond expectations if we are required by the FDA, or foreign regulatory 
agencies, to perform studies and clinical trials in addition to those that we currently anticipate, or if there are any delays 
in our or our partners completing clinical trials or the development of any of our product candidates. 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. Our failure to become and remain profitable would decrease the value of the company and 
could impair our ability to raise capital, maintain our development efforts, expand our business, or continue our 
operations and may require us to raise additional capital that may dilute your ownership interest. A decline in the value 
of our company could also cause you to lose all or part of your investment. 

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, manufacturing products, establishing marketing and sales capabilities to 
commercialize our product candidates, 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 collaborator payments will be sufficient 
to meet our current and projected operating and capital requirements for at least the next 12 months. Conducting 
preclinical studies and clinical trials is a time-consuming, expensive, and uncertain process that can take years to 
complete, and we may never generate the necessary data or results required to obtain marketing approval and achieve 
product sales. In addition, our product candidates, if approved, may not achieve commercial success. Our commercial 
revenues, if any, will be derived from sales of products that may not be commercially available for several years, if ever. 
Accordingly, we may need to continue to rely on additional financing to achieve our business objectives. 

In addition, we cannot provide assurance that anticipated collaborator payments will, in fact, be received. 
Should such future collaborator payments not be received, we expect we could seek additional funding from other 
sources. We may elect or need to seek additional financing sooner due to a number of other factors as well, including: 

(cid:131) 

(cid:131) 

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; and 

acquisition of technologies and other business opportunities that require financial commitments. 

20 

Additional funding may not be available to us in sufficient amounts, on favorable terms, or at all. We may raise 
additional funds through public or private financings, collaborative arrangements, or other arrangements. Any additional 
fundraising efforts may divert our management from their day-to-day activities, which may adversely affect our ability 
to develop and commercialize our product candidates. Volatility in the financial markets has generally made equity and 
debt financing more difficult to obtain and may have a material adverse effect on our ability to meet our fundraising 
needs. Moreover, the terms of any financing may adversely affect the holdings or the rights of our stockholders and the 
issuance of additional securities, whether equity or debt, by us, or the possibility of such issuance, may cause the market 
price of our shares to decline. 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, including restructuring our 
operations, refinancing or restructuring our debt, 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. 

Our ability to use our net operating loss carryforwards and certain other tax attributes to offset future taxable 
income may be limited. 

Under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, a corporation that undergoes 

an “ownership change,” is subject to limitations on its ability to use its pre-change net operating loss carryforwards 
(NOLs), and other pre-change tax attributes (such as research tax credits) to offset its post-change income or taxes. For 
these purposes, an ownership change generally occurs where the equity ownership of one or more shareholders or groups 
of shareholders who own at least 5% of a corporation’s stock increases its ownership by more than 50 percentage points 
over its lowest ownership percentage within a three-year period. We may have experienced such ownership changes in 
the past, and we may experience shifts in our stock ownership, some of which are outside ImmunoGen’s control. These 
ownership changes may subject our existing NOLs or credits to substantial limitations under Sections 382 and 383. 
Accordingly, we may not be able to utilize a material portion of our NOLs or credits. As of December 31, 2020, we had 
federal NOLs of $471.6 million available to reduce federal taxable income, if any, that begin to expire in 2028 through 
2037, and $373.7 million of federal NOLs that can be carried forward indefinitely. As of December 31, 2020, we also 
had $70.4 million of federal credit carryforwards that expire beginning in 2022. Limitations on our ability to utilize those 
NOLs to offset U.S. federal taxable income could potentially result in increased future tax liability to us. In addition, at 
the state level, there may be periods during which the use of NOLs is suspended or otherwise limited, which could 
accelerate or permanently increase state taxes owed. 

Risks Related to Our Business and Industry 

A pandemic, epidemic, or outbreak of an infectious disease, such as the COVID-19 pandemic, may materially and 
adversely affect our business and our financial results. 

The spread of COVID-19 has affected segments of the global economy and may affect our operations, including 

the potential interruption of our clinical trial activities and our supply chain. The current outbreak of COVID-19 has 
spread worldwide, including countries where we are currently conducting our clinical trials, including our SORAYA and 
MIRASOL trials. The COVID-19 pandemic is still evolving, and to date has led to the implementation of various 
responses, including government-imposed quarantines, travel restrictions, and other public health safety measures, as 
well as reported adverse impacts on healthcare resources, facilities, and providers across the United States, and in other 
countries worldwide. The continued impact of COVID-19 may result in a period of business disruption, including delays 
in our clinical trials or delays or disruptions in our supply chain. 

The continued impact of COVID-19 globally could adversely affect our clinical trial operations in the United 
States and elsewhere, including our ability to recruit and retain patients, principal investigators, and site staff who, as 
healthcare providers, may have heightened exposure to COVID-19. For example, COVID-19 has slowed site activation 
and patient enrollment for SORAYA, which we believe will result in a limited delay of six- to eight-weeks in the 
availability of top-line data from this trial from mid-2021 to the third quarter of 2021. Even with the approval of vaccines 
for COVID-19, the pandemic may further delay enrollment in trials due to prioritization of hospital resources toward the 
pandemic, restrictions on travel, and some patients may be unwilling to enroll in our trials or be unable to comply with 
clinical trial protocols if quarantines or travel restrictions impede patient movement or interrupt healthcare services, 
which would delay our ability to conduct clinical trials or release clinical trial results. In addition, there could be a 
potential effect of COVID-19 to the business at FDA or other health authorities, which could result in delays of reviews 
and approvals, including with respect to our product candidates. COVID-19 may also affect employees of third-party 
contract research organizations located in affected geographies that we rely upon to carry out our clinical trials. 
Although we entered the pandemic with ample supply of our drug candidates and we believe we have sufficient 

21 

 
inventory on hand for all of our ongoing mirvetuximab monotherapy and combination trials, IMGN632 studies, and 
activities to support the Phase 1 study for IMGC936, the continuation of the COVID-19 pandemic, or the spread of 
another infectious disease, could also negatively affect the operations at our third-party manufacturers, which could 
result in delays or disruptions in the supply of our product candidates if we need additional materials. Additionally, 
although our supply partners have taken prospective measures that we believe will ensure our currently activated trial 
sites have sufficient safety stock of our drug candidates to weather disruptions in transportation or supply, interruption in 
the manufacture and/or global shipping affecting the transport of clinical trial materials, such as patient samples, product 
candidates, and other supplies used in our clinical trials may negatively affect our trials. 

In addition, in response to the pandemic and in accordance with direction from state and local government 
authorities, we have taken temporary precautionary measures intended to help minimize the risk of the virus to our 
employees, including initially requiring and now allowing most employees to work remotely (which in turn increases 
threats related to cyber security, data accessibility, and communication matters), and suspending all non-essential travel 
worldwide for our employees. In addition, industry events and in-person work-related meetings have been canceled, the 
continuation of which could negatively affect our business. 

The trading prices for our common stock and other biotechnology companies have also been highly volatile as a 
result of the COVID-19 pandemic. We, therefore, may face difficulties raising capital through sales of our common stock 
or equity linked to our common stock, or such sales may be on unfavorable terms or unavailable. 

We cannot presently predict the scope and severity of any additional potential business shutdowns or 

disruptions as a result of the COVID-19 pandemic. If we or any of the third parties with whom we engage, however, 
were to experience further shutdowns or other business disruptions, our ability to conduct our business in the manner and 
on the timelines presently planned could be materially and negatively affected, which could have a material adverse 
impact on our business and our results of operation and financial condition. 

If our Antibody-Drug Conjugate technology does not produce safe, effective, and commercially viable products or 
if such products fail to obtain or maintain FDA approval, our business will be severely harmed. 

Our ADC technology yields novel product candidates for the treatment of cancer. To date, only one ADC using 
our technology, Kadcyla, 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 as a result, our 
ADC technology may not result in any future meaningful benefits to us or for our current or potential collaborators. 
Furthermore, we are aware of only a limited number of other compounds that are based on technology similar to our 
ADC technology that have obtained marketing approval by the FDA. If our ADC technology fails to generate product 
candidates that are safe, effective, and commercially viable treatments for cancer or such product candidates fail to 
obtain or maintain FDA approval, our business will be severely harmed.  

Clinical trials for our product candidates and those of our collaborators 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 

collaborators 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 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. 
For example, despite encouraging results from earlier clinical trials of mirvetuximab, our FORWARD I Phase 3 clinical 
trial evaluating mirvetuximab compared to chemotherapy in women with FR(cid:302)-positive, platinum-resistant ovarian 
cancer, did not meet the primary endpoint in either the entire treatment population or the pre-specified high 
FR(cid:302) expression population. Based on post hoc exploratory analyses of the FORWARD I results and consultations with 
the FDA, we are conducting two new trials of mirvetuximab, SORAYA and MIRASOL, to support the potential 
approval of mirvetuximab as a monotherapy. The results of SORAYA and/or MIRASOL may not show positive results 
consistent with our post hoc exploratory analyses of the FORWARD I results or earlier successful trials of mirvetuximab 
as monotherapy which would cause significant harm to our business and future prospects.  

At any time during the clinical trials, we, our collaborators, or the FDA or other regulatory authority might 

delay or halt any clinical trials of our product candidates for various reasons, including: 

(cid:131) 

occurrence of unacceptable toxicities or side effects; 

22 

 
(cid:131) 
(cid:131) 

(cid:131) 

(cid:131) 

(cid:131) 
(cid:131) 
(cid:131) 

(cid:131) 

ineffectiveness of the product candidate; 

insufficient drug supply, including delays in obtaining supplies/materials necessary for manufacturing 
such drugs; 

negative or inconclusive results from the clinical trials, or results that necessitate additional nonclinical 
studies or clinical trials; 

delays in obtaining or maintaining required approvals from institutions, review boards, or other 
reviewing entities at clinical sites; 

delays in patient enrollment; 

insufficient funding or a reprioritization of financial or other resources; 

our or our collaborators’ inability to develop and obtain approval for any companion in 
vitro diagnostic devices that the FDA or other regulatory authority may conclude must be used with 
such product candidates to ensure their safe use; or 

other reasons that are internal to the businesses of our collaborators and third-party suppliers, 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 collaborators’ product candidates could severely harm our business. 

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

Even if clinical trials demonstrate the safety and efficacy of our and our collaborators’ product candidates and 

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

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(cid:131) 

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their level of clinical efficacy and safety; 

their advantage over alternative treatment methods; 

our/the marketer’s and our collaborators’ ability to gain acceptable reimbursement and the 
reimbursement policies of government and other third-party payers; and 

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 our products are established, physicians may elect not to recommend the therapies for 
any number of other reasons, including whether the physicians are already using competing products that satisfy their 
treatment objectives. 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 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: 

injury to our reputation and significant negative media attention; 

decreased demand for our product; 

(cid:131) 
(cid:131) 
(cid:131)  withdrawal of clinical trial volunteers; 
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(cid:131) 
(cid:131) 

distraction of management; and 

costs of litigation; 

substantial monetary awards to plaintiffs. 

We may not have sufficient resources to satisfy any liability resulting from these claims. While we currently 
have product liability insurance for products that are in clinical testing, our coverage may not be adequate in scope to 

23 

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 
collaborators 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 currently do not have the direct sales, marketing, or distribution capabilities necessary to successfully 
commercialize our products on a large scale and may be unable to establish such capabilities. 

We currently intend to commercialize mirvetuximab ourselves in the United States. We may choose to rely on 

third parties to market and sell mirvetuximab outside of the United States, either through distributor or outlicensing 
arrangements. For example, in October 2020, we entered into a collaboration and license agreement with Huadong under 
which Huadong will exclusively develop and commercialize mirvetuximab in Greater China. We retain all rights to 
mirvetuximab in the rest of the world. At this time, we do not have any significant direct sales, marketing, or distribution 
capabilities. In addition, arrangements with third parties to develop and commercialize mirvetuximab or other future 
potential products could significantly limit the revenues we derive from these compounds, and these third parties, 
including Huadong, may fail to commercialize our compounds successfully. 

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, Astellas, AstraZeneca/MedImmune, Daiichi Sankyo, GlaxoSmithKline, and AbbVie. 
Many of these organizations have substantially more experience and more capital, research and development, regulatory, 
manufacturing, human, and other resources than we do. As a result, they may: 

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develop products that are safer or more effective than our product candidates; 

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; 

devote greater resources to market or sell their products; 

adapt more quickly to new technologies and scientific advances; 

initiate or withstand substantial price competition more successfully than we can; 

(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 
(cid:131)  more effectively negotiate third-party licensing and collaboration arrangements; and 
(cid:131) 

take advantage of acquisitions or other opportunities more readily than we can. 

have greater success in recruiting skilled scientific workers from the limited pool of available talent; 

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 ACA, which included the BPCIA, amended the Public Health Service Act to create an 
abbreviated approval pathway for two types of “generic” biologics—biosimilars and interchangeable biologic products. 
The BPCIA establishes a pathway for the FDA approval of follow-on biologics and provides twelve years data 
exclusivity for reference products and an additional six-month exclusivity period if pediatric studies are conducted. In 
Europe, the EMA 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 United States 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 

24 

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. 

Risks Related to Our Dependence on Third Parties 

If our collaborators 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 affected. 

The development and commercialization of our product candidates depends, in part, upon the formation and 

maintenance of collaborative arrangements. Collaborations provide an opportunity for us to: 

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generate cash flow and revenue; 

fund some of the costs associated with our internal research and development, preclinical testing, 
clinical trials, and manufacturing; 

seek and obtain regulatory approvals faster than we could on our own; 

successfully commercialize existing and future product candidates; and 

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 collaborators may devote to our product candidates. 
Our collaborators 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 collaborators 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:131) 

a change in the collaborative partner’s strategic focus as a result of merger, management changes, 
adverse business events, or other causes; 

(cid:131) 

(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 

a change in the priority of the product candidate relative to other programs in the collaborator’s 
pipeline; 

a reassessment of the patent situation related to the compound or its target; 

a change in the anticipated competition for the product candidate; 

preclinical studies and clinical trial results; and 

a reduction in the financial resources the collaborator can or is willing to apply to the development of 
new compounds. 

Even if our collaborators continue their collaborative arrangements with us, they may nevertheless determine 

not to actively pursue the development or commercialization of any resulting products. Also, our collaborators may fail 
to perform their obligations under the collaborative agreements or may be slow in performing their obligations. Our 
collaborators 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 some cases, 
at the discretion of our collaborators. 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 the development and commercialization of the products could be severely 
limited or eliminated. 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 could be severely harmed. 

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

25 

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 manufacture bulk drug substance and convert it into filled and finished vials of drug product for clinical use. If 
our product requirements are significantly higher than we estimated, we may not be able to readily procure slots to 
manufacture bulk drug substance or to convert drug substance into filled and finished vials of drug product for clinical 
use. 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 are currently contractually required to obtain all of the DM4 used in mirvetuximab from a single third-party 
manufacturer, and any delay or interruption in such manufacturer’s operations could impair our ability to 
advance preclinical and clinical trials and commercialization of our product candidates and our collaborators’ 
products candidates. 

We rely on a sole third-party supplier, Società Italiana Corticosteroidi S.r.l, to manufacture the DM4 used in 
mirvetuximab. Any delay or interruption in the operations of our sole third-party supplier and/or our supply of DM4 
could lead to a delay or interruption in our manufacturing operations, preclinical studies, clinical trials, and 
commercialization of our product candidates and our collaborators’ product candidates, which could negatively affect 
our business. 

We currently rely on, and expect to continue to rely on, third-party manufacturers to produce our antibodies, 
linkers, payloads, drug substance, and drug product, and any delay or interruption in such manufacturers’ 
operations could impair our ability to advance clinical trials and commercialization of our product candidates. 

We rely on third-party contract manufacturers to produce sufficiently large quantities of drug materials that are 
and will be needed for clinical trials and commercialization of our potential products. We have established relationships 
with third-party manufacturers to provide materials for our clinical trials and are developing relationships with these and 
other third-party manufacturers that we believe will be necessary to continue the development of our product candidates 
and to supply commercial quantities of these product candidates, if they are approved. 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 applications for 
regulatory approval and the market introduction and subsequent commercialization of our potential products. Any such 
delays may lower our revenues and potential profitability. 

The facilities used to manufacture our product candidates (drug substance and drug product) must be inspected 

by the FDA (and other similar regulatory agencies outside the United States depending on where marketing 
authorizations are filed) before marketing authorizations are approved. Often, but not always, these inspections are 
triggered by marketing authorization submissions. In the United States, if we want to change manufacturers or add 
additional manufacturers after our product candidate is approved, the FDA must approve a supplemental BLA. We are 
completely dependent on our contract manufacturers for compliance with cGMPs in connection with the manufacture of 
our product candidates. If our contract manufacturers cannot successfully manufacture material that conforms to our 
specifications and the regulatory requirements of the FDA or others, we will not be able to use the products produced at 
their manufacturing facilities. In addition, we have no control over the ability of our contract manufacturers to maintain 
adequate quality control, quality assurance, and qualified personnel. If the FDA or a comparable foreign regulatory 
authority finds that these facilities do not comply with cGMP, we may need to find alternative manufacturing facilities, 
which would significantly impact our ability to develop, obtain marketing approval for, or market our product 
candidates, if approved. Further, our failure, or the failure of our third-party manufacturers, to comply with these or other 
applicable regulations could result in sanctions being imposed on us, including clinical holds, fines, injunctions, civil 
penalties, delays, suspension or withdrawal of approvals, license revocation, seizures or recalls of product candidates or 
drugs, if approved, operating restrictions and criminal prosecutions, any of which could significantly and adversely 
affect our business and supplies of our product candidates. 

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 
collaborators to perform its obligations under its agreement with us, including making any royalty, milestone, or other 

26 

payments to us, could have an adverse effect on our financial condition. Further, any material reduction by any one of 
our collaborators 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. 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. 

We depend on our collaborators 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 may receive are determined by our collaborators 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 
audit-related costs on our part. 

Royalty rates under our license agreements with our collaborators may vary over the royalty term depending on 
our intellectual property rights and the existence of certain third-party 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 if certain third-party products compete with the particular product covered by 
the license agreement. 

Risks Related to Our Intellectual Property 

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. We seek to protect our proprietary position by filing 
patent applications in the United States and in foreign countries that cover our novel product candidates and their uses, 
pharmaceutical formulations and dosages, and processes for the manufacture of them. Our patent portfolio currently 
includes both patents and patent applications. 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 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. In addition, the patent prosecution process is expensive and time-consuming. We may not be able to 
file and prosecute all necessary or desirable patent applications at a reasonable cost or in a timely manner. We may 
choose not to seek patent protection for certain innovations and may choose not to pursue patent protection in certain 
jurisdictions. Under the laws of certain jurisdictions, patents or other intellectual property rights may be unavailable or 
limited in scope. It is also possible that we will fail to identify patentable aspects of our research and development before 
it is too late to obtain patent protection. 

Patents and patent 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 United States 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. 

27 

The Leahy-Smith America Invents Act became fully effective in 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, the 
U.S. Supreme Court has become increasingly active in reviewing U.S. patent law in recent years, and the extent to which 
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 United States. 

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. If we are unable to prevent 
material disclosure of the trade secrets and other intellectual property related to our technologies to third parties, we may 
not be able to establish or maintain the competitive advantage that we believe is provided by such intellectual property, 
adversely affecting our market position and business and operational results. 

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 of which we are currently unaware with 
claims that cover the use or manufacture of our drug candidates or the practice of our related methods. Because patent 
applications can take many years to issue, there may be currently pending patent applications that may later result in 
issued patents that our drug candidates may infringe. 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 such 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. 

Any inability to license proprietary technologies or processes from third parties that 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 

28 

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 the 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 the patents held by 
others. 

Risks Related to Government Regulation 

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

We and our collaborators 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 collaborators, 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 outside of the United States, 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 regulatory approval requires the submission 
of extensive preclinical and clinical data and supporting information to the authorities for each indication to establish the 
product candidate’s safety and efficacy. Data obtained from preclinical and other nonclinical 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 collaborators’ product candidates, once obtained, may be withdrawn. The effect of 
government regulation may be to: 

(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 

delay marketing of potential products for a considerable period of time; 

limit the indicated uses for which potential products may be marketed; 

impose costly requirements on our activities; and 

place us at a competitive disadvantage to other pharmaceutical and biotechnology companies. 

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 regulatory policy during the period of product 
development, clinical trials, and regulatory review. Failure to comply with 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. 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 collaborators’ product candidates will remain subject to ongoing regulatory review even if they 
receive marketing approval. If we or our collaborators fail to comply with regulations applicable to approved 
products, these approvals could be lost and the sale of our or our collaborators’ products could be suspended. 

Even if we or our collaborators receive regulatory approval to market a particular product candidate, the 

approval could be conditioned on us or our collaborators 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 collaborators to withdraw it from the market, or impede or delay our or our 
collaborators’ ability to obtain regulatory approvals in additional countries. In addition, the manufacturer of the product 
and its facilities will continue to be subject to regulatory 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 do not have prior experience complying with regulations pertaining to products that have 
already received marketing approval and, therefore, we may be unable or slow to comply with existing regulations, 
including changes in existing regulatory requirements, or new regulations. Furthermore, our collaborators may be slow 

29 

to adapt, or may never adapt, to changes in existing regulatory requirements or adoption of new regulatory requirements 
pertaining to products that have already received approval. 

If we or our collaborators 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: 

restrictions on the products, manufacturers, or manufacturing processes; 

civil or criminal penalties; 

product seizures or detentions; 

fines; 

injunctions; 

(cid:131) 
(cid:131)  warning letters; 
(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 
(cid:131) 

import bans; 

voluntary or mandatory product recalls and publicity requirements; 

suspension or withdrawal of regulatory approvals; 

total or partial suspension of production; and 

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. 

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

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 United States, 
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 payers 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 United States and other major 
healthcare markets have been proposed and adopted in recent years. For example, the Medicare Prescription 
Drug, Improvement, and Modernization Act of 2003 created a limited prescription drug benefit for Medicare 
beneficiaries. 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 ACA was intended to broaden access to health insurance, 
reduce or constrain the growth of healthcare spending, enhance remedies against fraud and abuse, add new transparency 
requirements for the healthcare and health insurance industries, impose new taxes and fees on the health industry, and 
institute additional health policy reforms. It also required discounts under the Medicare drug benefit program and 
increased rebates on drugs covered by Medicaid and imposed an annual fee on sales by branded pharmaceutical 
manufacturers. The financial impact of these discounts, increased rebates and fees, and the other provisions of the ACA, 
some of which may not have been completely implemented, on our business is unclear and there can be no assurance 
that our business will not be materially adversely affected by the ACA. The ACA has been under scrutiny by the U.S. 
Congress almost since its passage, and certain sections of the ACA have not been fully implemented or have effectively 
been repealed, for example, as part of the Tax Cuts and Jobs Act, the U.S. Congress eliminated the ACA’s individual 

30 

mandate. The longevity of other key provisions of the ACA continues to be uncertain, although the new Biden 
administration has indicated its desire to support and expand the ACA. In addition, ongoing initiatives in the United 
States have increased and will continue to increase pressure on drug 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. 

In 2016, the 21st Century Cures Act was signed into law. This law is intended to enable the acceleration of the 

discovery, development, and delivery of 21st century cures, among other things. Provisions in that law, such as those 
applying to precision medicine, technical updates to clinical trial databases, and advancing new drug therapies, could 
apply directly or indirectly to our activities and those of our collaborators. At this point, however, it is not clear when 
that law will be fully implemented and what effect it may have on our business. 

If we fail to comply with environmental, health, and safety laws and regulations that apply to us, we could become 
subject to fines or penalties or incur costs that could harm our business. 

We are subject to numerous federal, state, and local environmental, health, and safety laws and regulations, 

including those governing the manufacture and transportation of hazardous materials and pharmaceutical compounds. 
Although we believe that our contracted research, development, and manufacturer 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 with these laws in the future, including civil or criminal fines and penalties, 
which we may not be able to afford. 

In addition, we may incur substantial costs in order to comply with current or future environmental, health, and 

safety laws and regulations applicable to us. These current or future laws and regulations may impair our research, 
development, or production efforts or impact the research activities we pursue, particularly with respect to research 
involving human subjects or animal testing. Our failure to comply with these laws and regulations also may result in 
substantial fines, penalties, or other sanctions, which could cause our financial condition to suffer. 

Failure to comply with the Foreign Corrupt Practices Act and other similar anti-corruption laws and anti-money 
laundering laws, as well as export control laws, customs laws, sanctions laws, and other laws governing our 
operations could subject us to significant penalties and damage our reputation. 

We are subject to the Foreign Corrupt Practices Act (FCPA), which generally prohibits U.S. companies and 

intermediaries acting on their behalf from offering or making corrupt payments to “foreign officials” for the purpose of 
obtaining or retaining business or securing an improper business advantage. The FCPA also requires companies whose 
securities are publicly listed in the United States to maintain accurate books and records and to maintain adequate 
internal accounting controls. We are also subject to other similar anti-corruption laws and anti-money laundering laws, 
as well as export control laws, customs laws, sanctions laws, and other laws that apply to our activities in the countries 
where we operate. Certain of the jurisdictions in which we conduct or expect to conduct business have heightened risks 
for public corruption, extortion, bribery, pay-offs, theft, and other fraudulent practices. In many countries, health care 
professionals who serve as investigators in our clinical studies, or may prescribe or purchase any of our product 
candidates if they are approved, are employed by a government or an entity owned or controlled by a government. 
Dealings with these investigators, prescribers, and purchasers are subject to regulation under the FCPA. Under these 
laws and regulations, as well as other anti-corruption laws, anti-money-laundering laws, export control laws, customs 
laws, sanctions laws, and other laws governing our operations, various government agencies may require export licenses, 
may seek to impose modifications to business practices, including cessation of business activities in sanctioned countries 
or with sanctioned persons or entities and modifications to compliance programs, which may increase compliance costs, 
and may subject us to fines, penalties, and other sanctions. 

Inadequate funding for the FDA, the Securities and Exchange Commission, and other government agencies could 
hinder their ability to hire and retain key leadership and other personnel, prevent new products and services 
from being developed or commercialized in a timely manner, or otherwise prevent those agencies from 
performing normal business functions, which could negatively impact our business. 

The ability of the FDA to review and approve new products can be affected by a variety of factors, including 

government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and 
statutory, regulatory, and policy changes. Average review times at the agency have fluctuated in recent years as a result. 
In addition, government funding of the U.S. Securities and Exchange Commission (SEC) and other government agencies 

31 

on which our operations may rely, including those that fund research and development activities is subject to the political 
process, which is inherently fluid and unpredictable. 

Disruptions at the FDA and other agencies may also slow the time necessary for new drugs to be reviewed 

and/or approved by necessary government agencies, which would adversely affect our business. For example, over the 
last several years, including December 22, 2018 to January 25, 2019, the U.S. government has shut down several times, 
and certain regulatory agencies, such as the FDA and the SEC, have had to furlough employees and stop critical 
activities. If a prolonged government shutdown or a series of shutdowns occurs, it could significantly affect the ability of 
the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our 
business. Further, future government shutdowns could impact our ability to gain access to the public markets and obtain 
necessary capital in order to properly capitalize and continue our operations. 

We may be subject to, or may in the future become subject to, U.S. federal and state and foreign laws and 
regulations imposing obligations on how we collect, use, disclose, store, and process personal information. Our 
actual or perceived failure to comply with such obligations could result in liability or reputational harm and 
adversely affect our business. Ensuring compliance with such laws could also impair our efforts to maintain and 
expand our customer base, and thereby decrease our revenue. 

In many activities, including the conduct of clinical trials, we are subject to laws and regulations governing data 

privacy and the protection of health-related and other personal information. These laws and regulations govern our 
processing of personal data, including the collection, access, use, analysis, modification, storage, transfer, security 
breach notification, destruction, and disposal of personal data. We must comply with laws and regulations associated 
with the international transfer of personal data based on the location in which the personal data originates and the 
location in which such data are processed. While we strive to comply with all applicable privacy and security laws and 
regulations, legal standards for privacy continue to evolve and any failure or perceived failure to comply may result in 
proceedings or actions against us by government entities or others, or could cause reputational harm, which could have a 
material adverse effect on our business. 

The legislative and regulatory landscape for privacy and data security continues to evolve. For example, the EU 

General Data Protection Regulation (GDPR), which was effective as of May 25, 2018, introduced new data protection 
requirements in the European Union relating to the consent of the individuals to whom the personal data relate, the 
information provided to the individuals, the documentation we must retain, the security and confidentiality of the 
personal data, data breach notification, and the use of third party processors in connection with the processing of 
personal data. The GDPR has increased our responsibility and potential liability in relation to personal data that we 
process, and we may be required to put in place additional mechanisms to ensure compliance with the GDPR. However, 
our ongoing efforts related to compliance with the GDPR may not be successful and could increase our cost of doing 
business. In addition, data protection authorities of the different EU member states may interpret the GDPR differently, 
and guidance on implementation and compliance practices are often updated or otherwise revised, which adds to the 
complexity of processing personal data in the European Union. It is also not yet clear how the United Kingdom’s 
withdrawal from the European Union, or BREXIT, will affect the approval, distribution, and marketing of medicinal 
products in the United Kingdom. 

In the United States, California adopted the California Consumer Privacy Act of 2018 (CCPA), which became 

effective in January 2020. The CCPA has been characterized as the first “GDPR-like” privacy statute to be enacted in 
the United States because it mirrors a number of the key provisions of the EU GDPR. The CCPA establishes a new 
privacy framework for covered businesses by creating an expanded definition of personal information, establishing new 
data privacy rights for consumers in the State of California, imposing special rules on the collection of consumer data 
from minors, and creating a new and potentially severe statutory damages framework for violations of the CCPA and for 
businesses that fail to implement reasonable security procedures and practices to prevent data breaches. 

Risks Related to Our Key Personnel and Other Service Providers 

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. Although we have entered into 
employment agreements with our executive officers, each of them may terminate their employment with us at any time. 
We do not maintain “key person” insurance for any of our executives or other employees. In addition, we rely on 
consultants and advisors, including scientific and clinical advisors, to assist us in formulating our research and 
development and commercialization strategy. Our consultants and advisors may be employed by employers other than us 

32 

and may have commitments under consulting or advisory contracts with other entities that may limit their availability to 
us. If we are unable to continue to attract and retain high-quality personnel, our ability to pursue our growth strategy will 
be limited. We will also need to hire personnel with expertise in clinical testing, government regulation, manufacturing, 
sales, marketing, distribution, and finance. Attracting and retaining qualified personnel will be critical to our success. We 
may not be able to attract and retain personnel, or, in the event key personnel leave, suitable replacements for such 
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 employees, independent contractors, principal investigators, CROs, consultants, and collaborators may 
engage in misconduct or other improper activities, including noncompliance with regulatory standards and 
requirements and insider trading. 

We are exposed to the risk that our employees, independent contractors, principal investigators, third-party 

contract research organizations (CROs), consultants, and collaborators may engage in fraudulent conduct or other illegal 
activity. Misconduct by these parties could include intentional, reckless and/or negligent conduct or unauthorized 
activities that violate: (1) laws or regulations in jurisdictions where we are performing activities in relation to our 
product candidates, including those laws requiring the reporting of true, complete, and accurate information to such 
authorities; (2) manufacturing regulations and standards; (3) applicable laws prohibiting the promotion of a medical 
product for a use that has not been cleared or approved; (4) fraud and abuse, anti-corruption, and anti-money laundering 
laws, as well as similar laws and regulations and other laws; or (5) laws that require the reporting of true and accurate 
financial information and data. In particular, sales, marketing, and business arrangements in the healthcare industry are 
subject to laws intended to prevent fraud, bias, misconduct, kickbacks, self-dealing, and other abusive practices, and 
these laws may differ substantially from country to country. Misconduct by these parties could also include the improper 
use of information obtained in the course of clinical trials or performing other services, which could result in 
investigations, sanctions, and serious harm to their or our reputation. It is not always possible to identify and deter 
misconduct by these parties, and the precautions and procedures we currently take or may establish in the future as our 
operations and employee, CRO, consultant, and collaborator base expands to detect and prevent this type of activity may 
not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental 
investigations or other actions or lawsuits stemming from a failure by these parties to comply with such laws or 
regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting 
our rights, those actions could have a significant impact on our business and results of operations, including the 
imposition of significant fines or other sanctions. In addition, we have limited experience with respect to laws governing 
the commercial sale of pharmaceutical products, and we will need to implement measures to ensure compliance with 
these laws before the commercialization of any of our product candidates, if approved. The failure to adequately 
implement these measures could negatively affect our sales and marketing activities and our business. 

Risks Related to Our Technology Systems 

Our business and operations could suffer in the event of system failures. 

We utilize information technology systems and networks to process, transmit, and store electronic information 

in connection with our business activities. As use of digital technologies has increased, cyber incidents, including 
deliberate attacks and attempts to gain unauthorized access to computer systems and networks, have increased in 
frequency and sophistication. These threats pose a risk to the security of our systems and networks and the 
confidentiality, availability, and integrity of our data. There can be no assurance that we will be successful in preventing 
cyber-attacks or successfully mitigating their effects. 

Despite the implementation of security measures, our internal computer systems, and those of our CROs and 
other contractors and consultants, are vulnerable to damage from cyber-attack, computer viruses, unauthorized access, 
natural disasters, terrorism, war, and telecommunication and electrical failures. Furthermore, we have little or no control 
over the security measures and computer systems of our third-party CROs and other contractors and consultants. While 
we have not experienced any such system failure, accident, or security breach to date, if such an event were to occur and 
cause interruptions in our operations, it could result in a material disruption of our programs. For example, the loss of 
clinical trial data for our product candidates could result in delays in our marketing approval efforts and significantly 
increase our costs to recover or reproduce the data. To the extent that any disruption or security breach results in a loss of 
or damage to our data or applications or other data or applications relating to our technology or product candidates, or 

33 

inappropriate disclosure of confidential or proprietary information, we could incur liabilities and the further development 
of our product candidates could be delayed.  

Risks Related to the Ownership of Our Common Stock 

Our stock price may be volatile and fluctuate significantly and results announced by us and our collaborators or 
competitors could cause our stock price to decline. 

Our stock price could fluctuate significantly due to the risks listed in this section, business developments 
announced by us and by our collaborators and competitors, or as a result of market trends and daily trading volume. The 
business developments that could affect 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 or product candidates that compete with our compounds or those of our 
collaborators. Our stock price could also fluctuate significantly with the level of overall investment interest in small-cap 
biotechnology stocks or for other reasons unrelated to our business. 

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, decisions of our collaborators with 
respect to our agreements with them, and 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. 

We may seek additional capital due to market conditions or strategic considerations even if we believe we have 
sufficient funds for our current or future operating plans through a variety of means, including through private and public 
equity offerings and debt financings. To the extent that we raise additional capital through the sale of equity or 
convertible debt securities, ownership interest of existing shareholders will be diluted, and the price of our stock may 
decline. The price of our common stock may also decline if the market expects us to raise additional capital through the 
sale of equity or convertible debt securities whether or not we actually plan to do so. 

We do not intend to declare or pay cash dividends on our common stock in the foreseeable future. 

We have not declared or paid cash dividends on our common stock since our inception and do not intend to 

declare or pay cash dividends in the foreseeable future. We currently intend to retain all of our future earnings, if any, to 
finance the growth and development of our business. Therefore, shareholders will have to rely solely on appreciation in 
our stock price, if any, in order to achieve a gain on an investment. 

Item 1B.    Unresolved Staff Comments 

None. 

Item 2.    Properties 

We lease approximately 120,000 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. As a result of our July 2019 restructuring, we have sublet 
approximately 65,000 square feet of this space through the remaining term of the initial lease, and we will continue to 
use the remaining space. Additionally, in 2016, we entered into a lease agreement for the rental of 10,281 square feet of 
additional office space at 930 Winter Street, Waltham, MA through August 31, 2021. 

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. 

34 

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. 

Mark J. Enyedy, age 57, joined ImmunoGen in 2016, and has served as our President and Chief Executive 

Officer since that date. Prior to joining ImmunoGen, he served in various executive capacities at Shire PLC, a 
pharmaceutical company, from 2013 to 2016, including as Executive Vice President and Head of Corporate 
Development from 2014 to 2016, where he led Shire’s strategy, M&A, and corporate planning functions and provided 
commercial oversight of Shire’s pre-Phase 3 portfolio. Prior to joining Shire, he served as Chief Executive Officer and a 
director of Proteostasis Therapeutics, Inc., a biopharmaceutical company, from 2011 to 2013. Prior to joining 
Proteostasis, he served for 15 years at Genzyme Corporation, a biopharmaceutical company, most recently as President 
of the Transplant, Oncology, and Multiple Sclerosis divisions. Mr. Enyedy holds a JD from Harvard Law School and 
practiced law prior to joining Genzyme. Mr. Enyedy is also a director of Akebia Therapeutics, Inc., LogicBio 
Therapeutics, Inc., the Biotechnology Innovation Organization (BIO), and The American Cancer Society of Eastern New 
England. Within the past five years, he also served as a director of Fate Therapeutics, Inc. and Keryx 
Biopharmaceuticals, Inc. 

Anna Berkenblit, MD, age 51, joined ImmunoGen in 2015, and has served as our Senior Vice President and 

Chief Medical Officer since 2019. Prior to that, she served as our Vice President and Chief Medical Officer from 2015 to 
2019. Prior to joining ImmunoGen, she served as Senior Vice President and Head of Clinical Research at H3 
Biomedicine Inc., a pharmaceutical company, from 2013 to 2015. Dr. Berkenblit holds a Doctor of Medicine degree 
from Harvard Medical School and a master’s degree from the Harvard/MIT Health & Sciences clinical investigator 
training program. Dr. Berkenblit is also a director of Surrozen, Inc. 

Thomas Ryll, PhD, age 60, joined ImmunoGen in 2015, and has served as our Senior Vice President, Technical 

Operations, since 2019. Prior to that he served as our Vice President, Technical Operations, from 2017 to 2019, and as 
our Vice President, Process and Analytical Development, from his date of hire to 2017. Prior to joining ImmunoGen, he 
spent almost nine years at Biogen Inc. (formerly known as Biogen Idec Inc.), a biopharmaceutical company, in roles of 
increasing responsibility in the area of cell line culture development, including Senior Director in Biogen’s technical 
development department. Dr. Ryll holds a PhD in biotechnology and biochemistry from the Technical University of 
Braunschweig, Germany, and completed his post-doctoral work at the Society for Biotechnology Research (now the 
Helmholtz Center for Infection Research) in Germany. 

Theresa G. Wingrove, PhD, age 63, joined ImmunoGen in 2011, and has served as our Senior Vice President, 

Regulatory Affairs and Quality since 2018. Prior to that she served as our Vice President, Regulatory Affairs and Quality 
from 2017 to 2018, and prior to that as our Vice President, Regulatory Affairs for more than five years. Dr. Wingrove 
holds a PhD in biochemical toxicology from the University of Rochester School of Medicine and Dentistry and 
completed her postdoctoral work at the University of Rochester Medical Center. 

Stacy Coen, age 50, joined ImmunoGen in June 2020, and has served as our Senior Vice President and Chief 
Business Officer since that time. Ms. Coen joined ImmunoGen from Editas Medicine, a biopharmaceutical company, 
where she served as Vice President of Business Development, from 2017 to 2020. Prior to that, she spent twenty years in 
roles of increasing responsibility in the area of business development at Sanofi Genzyme, a pharmaceutical company, 
from 1997 to 2017. Ms. Coen holds an MBA, Business Management, Finance, and Healthcare, from the University of 
Virginia, Darden Graduate School of Business Administration. Ms. Coen currently serves as a member of the Board of 
Trustees of the Huntington’s Disease Society of America. 

Susan Altschuller, PhD, age 39, joined ImmunoGen in August 2020, and has served as our Senior Vice 

President and Chief Financial Officer, since that time. Dr. Altschuller joined ImmunoGen from Alexion 
Pharmaceuticals, where she served as Head of Investor Relations before moving to Head of Enterprise Finance, where 
she led global financial reporting and provided counsel on investment prioritization to support the Company’s strategic 
imperatives. Prior to joining Alexion, Dr. Altschuller was Head of Investor Relations at Bioverativ, where she served as 
the primary interface with Wall Street and led all investor-related activities for the launch of the Biogen spin-off.  Early 
in her career, Dr. Altschuller held positions at Biogen in various functions of increasing responsibility, including investor 
relations, corporate finance, and commercial finance. Dr. Altschuller holds a PhD in Biomedical Engineering from the 
Illinois Institute of Technology and an MBA from the MIT Sloan School of Management. 

35 

Item 4.    Mine Safety Disclosures 

None. 

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.” As of 
February 18, 2021, the closing price per share of our common stock was $9.30, as reported by Nasdaq, and we had 356 
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. 

36 

 
 
Item 6.    Reserved 

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

Overview 

We are a clinical-stage biotechnology company focused on developing the next generation of ADCs to improve 

outcomes for cancer patients. By generating targeted therapies with enhanced anti-tumor activity and favorable 
tolerability profiles, we aim to disrupt the progression of cancer and offer patients more good days. We call this our 
commitment to ‘‘target a better now.’’ 

An ADC with our proprietary technology comprises an antibody that binds to a target found on tumor cells and 
is conjugated to one of our potent anti-cancer agents as a ‘‘payload’’ to kill the tumor cell once the ADC has bound to its 
target. ADCs are an expanding approach to the treatment of cancer, with nine approved products and the number of 
agents in development growing significantly in recent years. 

We have established a leadership position in ADCs with a portfolio of differentiated product candidates to 

address both solid tumors and hematological malignancies. 

Managing the Impact of the COVID-19 Pandemic 

Since the first quarter of 2020, we have continued to move our clinical studies forward while adapting to meet 
the evolving challenges of the COVID-19 pandemic. We implemented business continuity plans in March 2020, which 
allowed our organization to effectively transition to working from home. Since then, we have worked closely with our 
external partners to monitor progress across our studies and to respond to new developments as they arise. From a 
manufacturing and supply chain perspective, we entered the pandemic with ample drug product and believe we have 
sufficient inventory on hand for all of our ongoing mirvetuximab soravtansine (mirvetuximab) monotherapy and 
combination trials, ongoing IMGN632 studies, and the Phase 1 study for IMGC936. Furthermore, our supply partners 
have taken prospective measures that we believe will ensure our currently activated study sites have sufficient safety 
stock of drug product to weather disruptions in transportation or supply. In addition, from a regulatory perspective, since 
the beginning of the pandemic, we have received timely reviews of our submissions to the FDA and other health 
authorities covering our clinical trial applications.  

We have maintained a high level of productivity since March 2020, when our workforce started working 

remotely, and are actively monitoring trial progress on a global scale. As disclosed in mid-2020, the impact of 
COVID-19 slowed site activation and patient enrollment for SORAYA, our single-arm clinical trial to support 
accelerated approval of mirvetuximab in folate receptor alpha (FR(cid:302))-high, platinum-resistant ovarian cancer, by six to 
eight weeks from our original estimates. Factoring in this delay and as previously reported, we expect to report top-line 
data from SORAYA in the third quarter of 2021 and anticipate submitting the biologics license application (BLA) for 
mirvetuximab in this setting by the end of 2021.  

Our Business 

Our lead program is mirvetuximab, a first-in-class investigational ADC targeting FR(cid:302), a cell-surface protein 

overexpressed in a number of epithelial tumors, including ovarian, endometrial, and non-small-cell lung cancers. In 
2019, FORWARD I, our Phase 3 clinical trial of mirvetuximab in patients with FR(cid:302)-positive, platinum-resistant ovarian 
cancer, did not meet its primary endpoint. In post hoc exploratory analyses in the FR(cid:302)-high population scored by the 
PS2+ method, however, mirvetuximab was associated with longer progression free survival, a higher overall response 
rate, and longer overall survival. 

Following consultation with the FDA, we moved forward with two new trials of mirvetuximab in FR(cid:302)-high, 

platinum-resistant ovarian cancer: SORAYA, a single-arm clinical trial that, if successful, could lead to accelerated 
approval in this setting; and MIRASOL, a randomized Phase 3 clinical trial that, if successful, could lead to full approval 
in this setting. We are actively enrolling both studies and expect to report top-line data from SORAYA in the third 
quarter of 2021 and top-line data from MIRASOL in the first half of 2022. If SORAYA is successful, we expect to 
submit an application for accelerated approval of mirvetuximab in the applicable patient population to the FDA by the 
end of 2021 and, thereafter, seek full approval on the basis of the confirmatory Phase 3 MIRASOL trial. 

Beyond our anticipated monotherapy indications, we are generating data for mirvetuximab in combination with 

other agents to expand into earlier lines of ovarian cancer therapy. In addition, we plan to support the initiation in 2021 
of two investigator-sponsored trials of mirvetuximab plus carboplatin, including a randomized Phase 2 study in recurrent  

37 

platinum-sensitive ovarian cancer and a neo-adjuvant study. With the benefit of these data, we believe there is potential 
for compendia listings for combination use of mirvetuximab and are also working to define the best path forward to label 
expansion.  

IMGN632 is an ADC comprised of a high-affinity antibody designed to target CD123 with site-specific 
conjugation to our most potent IGN payload. We are advancing IMGN632 in clinical trials for patients with BPDCN and 
AML. In October 2020, the FDA granted Breakthrough Therapy designation for IMGN632 for the treatment of patients 
with relapsed or refractory BPDCN. We are aligned with the FDA on a path to full approval in BPDCN, with an 
amendment to our ongoing 801 Phase 1/2 study to add a new cohort of up to 20 frontline patients. We expect to 
complete enrollment and generate top-line data in 12 to 18 months, with potential BLA submission in 2022.  

Our 802 study, which is a Phase 1b/2 study designed to determine the safety, tolerability, and preliminary 

antileukemia activity of IMGN632 when administered in combination with azacitidine and/or venetoclax to patients with 
relapsed and frontline CD123-positive AML, is in the dose-escalation phase, enrolling relapsed and refractory patients to 
determine the recommended Phase 2 dose of IMGN632 for combination regimens. We anticipate sharing data from this 
study in 2021. 

We continue to advance additional pipeline programs. IMGC936 is an ADC in co-development with 
MacroGenics designed to target ADAM9, an enzyme overexpressed in a range of solid tumors and implicated in tumor 
progression and metastasis. IMGC936 incorporates a number of innovations, including antibody engineering to extend 
the half-life, site-specific conjugation with a fixed drug-antibody ratio to enable higher dosing, and a next-generation 
linker and payload for improved stability and bystander activity. The IND for IMGC936 was accepted by the FDA in the 
second quarter of 2020 and we began enrollment in the Phase 1 study in the fourth quarter of 2020. 

IMGN151 is our next generation anti-FR(cid:302) candidate in preclinical development. This ADC integrates 
innovation in each of its components, which may enable IMGN151 to address patient populations with lower levels of 
FR(cid:302) expression, including tumor types outside of ovarian cancer. We presented encouraging data for IMGN151 at the 
American Academy of Cancer Research Virtual Annual Meeting II in June 2020. We expect to file the IND for 
IMGN151 by the end of 2021. 

We have selectively licensed restricted access to our ADC platform technology to other companies to expand 

the use of our technology and to provide us with cash to fund our own product programs. These agreements typically 
provide the licensee with rights to use our ADC platform 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, and royalties on the sales of any resulting 
products. 

In October 2020, we entered into a collaboration and license agreement with Huadong, a subsidiary of Huadong 

Medicine Co., Ltd., under which Huadong will exclusively develop and commercialize mirvetuximab in the People’s 
Republic of China, Hong Kong, Macau, and Taiwan, which we refer to as Greater China. Under the terms of the 
collaboration and license agreement, we received a non-refundable upfront payment of $40.0 million and are eligible to 
receive additional payments of up to $265.0 million as certain development, regulatory, and net sales milestones are 
achieved. We are also eligible to receive tiered low double digit to high teen royalties as a percentage of mirvetuximab 
commercial sales by Huadong in Greater China. Huadong is responsible for the development and commercialization of 
mirvetuximab in Greater China except in limited circumstances. We retain all rights to mirvetuximab in the rest of the 
world. 

We expect that substantially all of our revenue for at least the next year will result from payments under our 

collaborative arrangements. For more information concerning these relationships, including their ongoing financial and 
accounting impact on our business, please read Note C, “Significant Collaborative Agreements,” to our consolidated 
financial statements included in this report. 

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 December 31, 2020, we had $293.9 million in cash and cash 
equivalents compared to $176.2 million as of December 31, 2019. In January 2021, pursuant to an Open Market Sale 
AgreementSM, with Jefferies, LLC as sales agent, we sold 4.5 million shares of our common stock, generating net 
proceeds of $33.6 million after deducting underwriting discounts and offering expenses.  

38 

Critical Accounting Policies and Estimates 

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, 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. 

During 2019, we adopted Accounting Standards Codification (ASC) 842, Leases, using the transition method 

provided by Accounting Standards Update (ASU) No. 2018-11, Leases (Topic 842): Targeted Improvements. Under this 
method, we initially applied the new leasing rules on January 1, 2019, rather than at the earliest comparative period 
presented in the financial statements. Periods prior to adoption are presented in accordance with previous guidance 
issued under ASC 840, Leases. The adoption of ASC 842 represented a change in accounting principle that resulted in 
the recognition of lease assets and liabilities on the balance sheet, including those previously classified as operating 
leases under ASC 840, and disclosure of key information about leasing arrangements. Refer to Note B to the 
consolidated financial statements for further discussion on this change.  

Refer to Note B to the consolidated financial statements for further discussion regarding our critical accounting 

policies, including revenue recognition, clinical trial accruals, and stock-based compensation. 

Results of Operations 

For a discussion related to the results of operations for 2019 compared to 2018, refer to Part II, Item 7, 

"Management's Discussion and Analysis of Financial Condition and Results of Operations – Results of Operations" in 
our Annual Report on Form 10–K for the year ended December 31, 2019 filed with the SEC on March 11, 2020. 

Revenues 

For 2020, our total revenues increased to $132.3 million compared to $82.3 million for 2019, driven by 

increases in license and milestone fees and non-cash royalty revenue.  

License and milestone fees 

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 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 and milestone fees for the years ended 2020 and 2019 was $63.7 million and $34.8 
million, respectively. The increase in 2020 was driven by the recognition of $60.5 million of previously deferred license 
revenue upon Jazz’s opt-out of its right to the last remaining license under its collaboration and option agreement in 
December 2020, partially offset by license fee revenue recognized related to agreements with CytomX and Jazz and 
certain partner milestone fees recorded in the prior year.  

Deferred revenue of $110.1 million as of December 31, 2020 includes $40.0 million related to the collaboration 

with Huadong executed in October 2020 and $65.2 million related to the sale of our residual rights to receive royalty 
payments on commercial sales of Kadcyla in 2019, with the remainder of the balance primarily representing 
consideration received from our other collaborators pursuant to our license agreements which we have yet to earn 
pursuant to our revenue recognition policy. 

Non-cash royalty revenue related to the sale of future royalties 

In February 2013, the FDA granted marketing approval to Kadcyla, an ADC 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, $68.5 million and $47.4 million of non-cash royalties on net sales of Kadcyla were recorded and included in 
royalty revenue for 2020 and 2019, respectively. The increase in 2020 is a result of an increase in royalty payments 
driven by increases in net sales of Kadcyla due to market expansion of Kadcyla and approval of Kadcyla for a second 
indication in 2019. Kadcyla sales occurring after January 1, 2015 are covered by royalty purchase agreements. Pursuant 
to the terms of these agreements, we expect to recognize less non-cash royalty revenue during 2021 and subsequent 
years. See further details regarding the royalty obligation in Note F, “Liability Related to Sale of Future Royalties,” of 
the Consolidated Financial Statements.  

39 

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) external manufacturing operations, and prior to 2019, internal 
manufacturing operations, which also included raw materials. 

We restructured our business in 2019, the details of which are included under Restructuring Charges below. 

Research and development expense was $114.6 million and $114.5 million for 2020 and 2019, respectively, with lower 
personnel, administrative, laboratory, third-party research, and allocated facility expenses resulting from the 
restructuring at the end of the second quarter of 2019 offset by increases in clinical trial and antibody costs in the current 
year and less reimbursement pursuant to our cost-sharing agreement with Jazz due to the discontinuation of the 
IMGN779 program in connection with the restructuring.  

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 never 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 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 Category 
Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       $ 
Preclinical and clinical testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Process and product development  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Manufacturing operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Total research and development expense  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 

Research 

Years Ended 
December 31,  

2020 

2019 

 —      $ 

 75,430 
 5,430 
 33,732 
 114,592 

$ 

 12,272 
 71,193 
 7,807 
 23,250 
 114,522 

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, contract services, facility expenses, and laboratory supplies. There were no research expenses for 
2020 as a result of the restructuring of the business at the end of the second quarter of 2019.  

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 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 to $75.4 million for 2020 compared to $71.2 million for 2019. This 

40 

 
 
 
 
 
 
 
 
 
 
 
 
     
 
 
 
 
 
 
increase is primarily the result of increased clinical trial costs driven by costs incurred related to advancing the 
MIRASOL, SORAYA, IMGN632, and IMGC936 studies and less reimbursement recorded in the current year pursuant 
to our cost-sharing agreement with Jazz. Partially offsetting these increases were lower personnel, administrative, 
laboratory, and allocated facility expenses resulting from the restructuring of the business, lower clinical trial costs 
related to the FORWARD I, FORWARD II, and IMGN779 studies, and a decrease in contract services driven by certain 
regulatory and pre-commercial activities related to mirvetuximab and preclinical development of IMGC936 in the prior 
year. 

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, laboratory supplies, and facility expenses. Process and product development expenses decreased to 
$5.4 million for 2020 compared to $7.8 million for 2019. This decrease is principally due to a decrease in personnel 
expenses, laboratory supplies, and allocated facility expenses as a result of the restructuring of the business, partially 
offset by an increase in contract services driven by greater activity related to our IMGN151 and IMGC936 programs and 
less reimbursement recorded in the current period pursuant to our cost-sharing agreement with Jazz.  

Manufacturing operations 

Manufacturing operations expense includes costs to have preclinical and clinical materials manufactured for our 

product candidates and quality control and quality assurance activities. Such expenses include personnel, raw materials 
for our preclinical studies and clinical trials, non-pivotal and pivotal development costs with contract manufacturing 
organizations, and facility expenses. Manufacturing operations expense increased $10.5 million to $33.7 million for 
2020. The increase in 2020 is principally due to greater external manufacturing costs related to the potential commercial 
launch of mirvetuximab and less reimbursement recorded in the current period pursuant to our cost-sharing agreement 
with Jazz, partially offset by lower personnel, administrative, and facility-related expenses resulting from the shut-down 
of our manufacturing facility in February 2019 and the restructuring of the business at the end of the second quarter of 
2019.  

Antibody development and supply expense in support of commercial validation and in anticipation of potential 

future clinical trials, as well as our ongoing trials, was $20.2 million and $8.3 million for 2020 and 2019, respectively. 
Development and supply expenses related to the potential commercial launch of mirvetuximab drove the increased spend 
in 2020. 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. 

General and Administrative Expenses 

General and administrative expenses increased $0.1 million to $38.6 million for 2020 due primarily to a higher 

allocation of facility-related expenses for excess laboratory and office space and an increase in professional services, 
substantially offset by a decrease in personnel and administrative expenses resulting from the prior year restructuring.  

Restructuring Charges 

On June 26, 2019, the Board of Directors approved a plan to restructure the business to focus resources on 

continued development of mirvetuximab and a select portfolio of three earlier-stage product candidates, resulting in a 
significant reduction of our workforce, with a majority of these employees separating from the business by mid-
July 2019 and most of the remaining affected employees transitioning over varying periods of time of up to 12 months. 
Communication of the plan to the affected employees was substantially completed on June 27, 2019. 

 As a result of the workforce reduction, we recorded a charge of $16.0 million for severance related to a pre-

existing plan in June 2019, which was subsequently reduced to $15.3 million due to minor adjustments to the plan. The 
related cash payments were substantially paid out by June 30, 2020. In addition, a charge of $4.0 million was recorded 
for incremental retention benefits in the same time period, of which $1.6 million and $2.4 million was recorded during 
2020 and 2019, respectively. 

In addition to the termination benefits and other related charges, we sub-leased the majority of the laboratory 
and office space at 830 Winter Street in Waltham, Massachusetts and liquidated excess equipment. In performing the 
required impairment test, we recorded a charge of $2.5 million in June 2019 to write down the equipment to fair value; 
however, we determined the right-to-use asset related to the lease was recoverable, therefore, no impairment was 
recorded.  

41 

Charge Related to Unoccupied Office Space 

We have sought to sub-lease 10,281 square feet of unoccupied office space in Waltham that was leased in 2016. 

During 2019, we recorded a $0.6 million impairment charge related to this lease, which represented the remaining 
balance of the right to use asset as the likelihood of finding a sub-lessor had diminished significantly as the lease 
approached termination.  

Investment Income, net 

Investment income for 2020 and 2019 was $0.7 million and $4.4 million, respectively. The decrease in 2020 

was primarily due to a significant decrease in interest rates. 

Non-Cash Interest Expense on Liability Related to Sale of Future Royalty 

In 2015, IRH purchased our right to receive 100% of the royalty payments on commercial sales of Kadcyla 

arising under our development and commercialization license with Genentech, subject to a residual cap. In January 2019, 
OMERS purchased IRH’s right to the royalties the Company previously sold as described above. As described in Note F 
to our Consolidated Financial Statements, this royalty sale transaction has been recorded as a liability that amortizes over 
the estimated royalty payment period as Kadcyla royalties are remitted directly to the purchaser. During 2020 and 2019, 
we recorded $23.1 million and $16.9 million, respectively, of non-cash interest expense. The increase in 2020 was a 
result of increases in royalty payments driven by increases in net sales of Kadcyla and greater projected future royalty 
payments due to market expansion of Kadcyla and approval of Kadcyla for a second indication in 2019. We impute 
interest on the transaction and record interest expense at the effective interest rate, which we currently estimate to be 
22.2%. There are a number of factors that could materially affect the estimated interest rate, in particular, the amount and 
timing of royalty payments from future net sales of Kadcyla, and we assess this estimate on a periodic basis. As a result, 
future interest rates could differ significantly and any such change in interest rate will be adjusted prospectively. 

Interest Expense on Convertible Senior Notes 

In June 2016, the Company issued Convertible 4.5% Senior Notes with an aggregate principal amount of $100 

million. The Convertible Notes are senior unsecured obligations and bear interest at a rate of 4.5% per year, payable 
semi-annually in arrears on January 1 and July 1 of each year, commencing on January 1, 2017. During the second half 
of 2017, $97.9 million of this debt was converted to common shares. For 2020 and 2019, we recorded $95,000 of interest 
expense in each year.  

Other Income (Expense), net 

Other income (expense), net for 2020 and 2019 was $0.5 million and $0.6 million, respectively. This includes 

$0.5 million and $(0.2) million in foreign currency exchange gains (losses) related to obligations with non-U.S. 
dollar-based suppliers and Euro cash balances maintained to fulfill them during the same periods, respectively. In 
addition, we recorded a gain of $0.8 million in 2019 related to the sale of excess laboratory equipment resulting from the 
restructuring. 

Liquidity and Capital Resources  

For a discussion related to our cash flows for 2019 compared to 2018, refer to Part II, Item 7, "Management's 

Discussion and Analysis of Financial Condition and Results of Operations – Liquidity and Capital Resources" in our 
Annual Report on Form 10–K for the year ended December 31, 2019 filed with the SEC on March 11, 2020. 

The following tables show certain balance sheet and cash flow information as of and for the periods indicated 

(in thousands): 

Cash and cash equivalents  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        $   293,856      $   176,225 
 131,488 
Working capital . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     
Shareholders’ equity (deficit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     
 (76,121)

 201,931  
 89,570  

As of December 31,  
2019 

2020 

42 

 
 
 
 
 
 
 
  
 
  
 
Cash used for operating activities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       $ 
Cash provided by (used for) investing activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Cash provided by financing activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    

Cash Flows 

Years Ended December 31 

2020 
 (78,620)    $ 
 509  
 195,742  

2019 
 (88,367)
 (533)
 2,873 

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

make capital expenditures. Historically, we have funded our cash requirements primarily through equity and convertible 
debt financings in public markets and payments from our collaborators, including license fees, milestones, research 
funding, and royalties. We have also monetized our rights to receive royalties on Kadcyla for up-front consideration. As 
of December 31, 2020, we had $293.9 million in cash and cash equivalents. Net cash used for operating activities was 
$78.6 million and $88.4 million during 2020 and 2019, respectively. The principal use of cash in operating activities for 
these periods was to fund our net loss, adjusted for non-cash items, with 2020 benefiting from a $40.0 million upfront 
payment from Huadong pursuant to a collaboration and license agreement and 2019 benefiting from $65.2 million of net 
proceeds from the sale of our residual rights to royalty payments on net sales of Kadcyla.  

Net cash provided by (used for) investing activities was $0.5 million and $(0.5) million for 2020 and 2019, 

respectively, and represent cash outflows from capital expenditures, net of proceeds generated from the sale of capital 
assets. Capital expenditures for all periods presented consisted primarily of leasehold improvements to the office space 
at our corporate headquarters, computer software applications, and dedicated equipment at third-party manufacturing 
vendors. During 2020 and 2019, as a result of the restructuring, we sold excess equipment generating proceeds of $1.5 
million and $2.3 million, respectively. 

Net cash provided by financing activities was $195.7 million and $2.9 million for 2020 and 2019, respectively. 
In January 2020, pursuant to a public offering, we issued and sold 24.5 million shares of common stock, resulting in net 
proceeds of $97.7 million. Additionally in 2020, we entered into an Open Market Sale AgreementSM (September Sale 
Agreement) with Jefferies, LLC as sales agent, pursuant to which we offered and sold 19,972,557 shares of our common 
stock resulting in net proceeds of $96.5 million after deducting offering commissions and expenses, effectively closing 
the September Sale Agreement.   

Net cash provided by financing activities for 2020 and 2019 also include proceeds from the exercise of stock 

options and sale of shares through our ESPP.  

On December 18, 2020, we entered into a new Open Market Sale AgreementSM (Sale Agreement), with 

Jefferies, LLC as sales agent, pursuant to which we may offer and sell, from time to time, shares of our common stock 
having an aggregate offering price of up to $150.0 million. In connection with entering into the Sale Agreement, we filed 
a prospectus supplement to the prospectus included in our registration statement on Form S-3 (No. 333-251502), which 
became effective upon filing on December 18, 2020, with the SEC relating to the offer and sale of the up to $150.0 
million of our common stock under the Sale Agreement. Through the date of filing this report, we have sold 4,544,424 
shares of our common stock under the Sale Agreement, generating net proceeds of $33.6 million after deducting offering 
commissions and expenses. None of the sales under the Sale Agreement occurred during the year ended December 31, 
2020.  

We anticipate that our current capital resources will enable us to meet our operational expenses and capital 

expenditures for more than twelve months after the date of this report. We may raise additional funds through equity, 
debt, and other financings or generate revenues from collaborators through a combination of upfront license payments, 
milestone payments, royalty payments, and research funding. We cannot provide assurance that we will be able to obtain 
additional debt, equity, or other financing or generate revenues from collaborators on terms acceptable to us or at all. 
Should we or our partners not meet some or all of the terms and conditions of our various collaboration agreements or if 
we are not successful in securing future collaboration agreements, we may elect or be required to secure alternative 
financing arrangements, and/or defer or limit some or all of our research, development, and/or clinical projects.  

Contractual Obligations   

We lease approximately 120,000 square feet of laboratory and office space in a building located at 830 Winter 

Street, Waltham, Massachusetts, with an initial term that expires on March 31, 2026, and 10,281 square feet of 
additional office space at 930 Winter Street, Waltham, Massachusetts through August 31, 2021. We are obligated to pay 
$28.4 million in minimum rental payments over the remaining terms of these leases. In addition, we are responsible for  

43 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
  
  
  
  
variable operating costs and real estate taxes approximating $3.1 million per year through March 2026. In 2020, we 
executed four agreements to sublease a total of approximately 65,000 square feet of the 830 Winter Street facility 
through March 2026. Two of the four sublease agreements include an early termination option after certain periods of 
time for an agreed-upon fee. Assuming these early termination options are not exercised, we will receive $15.9 million 
in minimum rental payments over the remaining term of the subleases. The sublessees will also be responsible for their 
proportionate share of variable operating expenses and real estate taxes.  

As of December 31, 2020, we have noncancelable obligations under several agreements related to in-process 

and future manufacturing of antibody and cytotoxic agents required for clinical supply of our product candidates totaling 
$6.5 million, which will be paid in 2021. Additionally, pursuant to commercial agreements for future production of 
antibody, our noncancelable commitments total approximately $36.0 million at December 31, 2020. 

Recent Accounting Pronouncements 

The information set forth under Note B to the consolidated financial statements under the caption “Summary of 

Significant Accounting Policies” is incorporated herein by reference. 

Third-Party Trademarks 

Kadcyla and Herceptin are registered trademarks of Genentech, Inc. Probody is a trademark of CytomX. 

44 

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. Our 
investments are comprised of money market funds consisting principally of U.S. Government-issued securities and high 
quality, short-term commercial paper. We do not currently 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 either forward contracts or 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 December 31, 2020. Accordingly, we do 
not believe there is any material market risk exposure with respect to foreign currency exposures that would require 
disclosure under this item. 

45 

 
 
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 December 31, 2020 and 2019  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Consolidated Statements of Operations and Comprehensive Loss for the Years Ended December 31, 2020, 

2019, and 2018  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  

Consolidated Statements of Shareholders’ Equity (Deficit) for the Years Ended December 31, 2020, 2019, 

and 2018  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Consolidated Statements of Cash Flows for the Years Ended December 31, 2020, 2019, and 2018   . . . . . . . . . .  
Notes to Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  

Page 
47

49

50

51
52
53

46 

 
 
 
 
 
 
To the Shareholders and the Board of Directors of ImmunoGen, Inc. 

Report of Independent Registered Public Accounting Firm 

Opinion on the Financial Statements 
We have audited the accompanying consolidated balance sheets of ImmunoGen, Inc. (the Company) as of December 31, 
2020 and 2019, the related consolidated statements of operations and comprehensive loss, shareholders' equity (deficit) 
and  cash  flows  for  each of  the  three  years  in  the  period  ended December 31, 2020,  and  the  related notes (collectively 
referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, 
in  all  material  respects,  the  financial  position  of  the  Company  at  December 31,  2020  and  2019,  and  the  results  of  its 
operations and its cash flows for each of the three years in the period ended December 31, 2020  in conformity with U.S. 
generally accepted accounting principles.  

We  also  have  audited,  in  accordance  with  the  standards  of  the  Public  Company  Accounting  Oversight  Board  (United 
States)  (PCAOB),  the  Company's  internal  control  over  financial  reporting  as  of  December 31,  2020,  based  on  criteria 
established  in  Internal  Control-Integrated  Framework  issued  by  the  Committee  of  Sponsoring  Organizations  of  the 
Treadway Commission (2013 framework) and our report dated March 1, 2021 expressed an unqualified opinion thereon. 

Adoption of ASU No. 2016-02 
As discussed in Note B to the consolidated financial statements, the Company has changed its method of accounting for 
leases as of January 1, 2019 due to the adoption of ASU No. 2016-02, Leases (Topic 842), and the related amendments.  

Basis for Opinion 
These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion 
on the Company’s financial statements based on our audits. We are a public accounting firm registered with the PCAOB 
and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and 
the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.  

We  conducted  our  audits  in  accordance  with  the  standards  of  the  PCAOB.  Those  standards  require  that  we  plan  and 
perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, 
whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of 
the  financial  statements,  whether  due  to  error  or  fraud,  and  performing  procedures  that  respond  to  those  risks.  Such 
procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. 
Our audits also included evaluating the accounting principles used and significant estimates made by management, as well 
as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for 
our opinion. 

Critical Audit Matters 
The critical audit matters communicated below are matters arising from the current period audit of the financial statements 
that  were  communicated  or  required  to  be  communicated  to  the  audit  committee  and  that:  (1) relate  to  accounts  or 
disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex 
judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial 
statements,  taken  as  a  whole,  and  we  are  not,  by  communicating  the  critical  audit  matters  below,  providing  separate 
opinions on the critical audit matters or on the accounts or disclosures to which they relate. 

Clinical Trial Accrual 

Description of the 
Matter 

As  discussed  in  Note  B  to  the  consolidated  financial  statements,  the  Company  estimates  certain 
clinical trial expenses due to a lag in receiving information from third parties. Moreover, payments 
for these activities are based on the terms of the individual arrangements, which may differ from the 
pattern  of  costs  incurred.  The  Company  maintained  a  clinical  trial  accrual  of  $11.4  million  at 
December 31, 2020 included as a component of other accrued liabilities. 

Auditing  the  Company’s  clinical  trial  accruals  was  especially  challenging  due  to  the  significant 
management judgment used to estimate the patient-related costs incurred but not yet invoiced. While 
the Company’s estimates of patient-related costs incurred but not yet invoiced are primarily based on 
information received from its vendors related to each clinical trial, the Company may need to use 
significant assumptions such as estimates of patient enrollment, patient cycles incurred, clinical sites 
activated, and other pass-through costs. Additionally, due to the duration of the clinical trials as well 
as the timing of invoices received from vendors, actual amounts incurred are not typically known at 
the time the financial statements are issued. 

47 

 
 
 
 
 
 
 
 
 
 
 
How We 
Addressed the 
Matter in Our 
Audit 

We obtained an understanding, evaluated the design and tested the operating effectiveness of internal 
controls related to clinical trial accruals. For example, we tested management’s review controls over 
the accuracy and completeness of the underlying data and the significant assumptions used in the 
Company’s process for recording accrued patient-related costs. 

Description of the 
Matter 

Our audit procedures to test clinical trial accruals included, among others, testing the accuracy and 
completeness of the underlying data used to estimate costs incurred but not yet invoiced as well as 
evaluating and testing the significant assumptions used by management. We inspected the contracts 
and any amendments to the contracts with third parties and assessed the pattern of historical invoicing 
activity and the associated billing lags. We also corroborated the progress of clinical trials and other 
research and development projects through discussion with the Company’s research and development 
personnel  that  oversee  the  clinical  trials.  In  addition,  we  inspected  information  obtained  by  the 
Company directly from third-party vendors, which included the third-party vendors’ estimate of costs 
incurred to date. We also performed analytical procedures over clinical trial accruals and compared 
subsequent invoices received from third-party vendors to the amounts accrued. 

Collaboration and License Agreement with Huadong   

As  discussed  in  Note  C  to  the  consolidated  financial  statements,  in  October 2020,  the  Company 
entered  into  a  collaboration  and  license  agreement  with  Hangzhou  Zhongmei  Huadong 
Pharmaceutical  Co.,  Ltd.  (Huadong).  Under  the  agreement,  the  Company  granted  Huadong  an 
exclusive right to develop and commercialize mirvetuximab soravtansine in the People’s Republic 
of  China,  Hong  Kong,  Macau,  and  Taiwan  and  agreed  to  provide  clinical  supply  of  the  licensed 
product to Huadong for a specified period. The Company received a $40.0 million up-front payment 
during  2020  in  connection  with  this  arrangement  and  is  also  eligible  to  receive  additional 
development  and  regulatory  milestone  payments,  sales-based  milestones  and  royalties  as  well  as 
additional payments for clinical supply under the arrangement.  

Auditing the Company’s revenue recognition for the Huadong collaboration and license agreement 
was  challenging  because  significant  judgment  was  required  to  apply  the  authoritative  accounting 
guidance  at  the  outset  of  the  arrangement.  The  Company  exercised  significant  judgment  in 
determining the revenue recognition for this arrangement, including as it relates to the identification 
of performance obligations. 

How We 
Addressed the 
Matter in Our 
Audit 

We obtained an understanding, evaluated the design and tested the operating effectiveness of internal 
controls related to the accounting for the collaboration and license agreement. For example, we tested 
controls over the identification of performance obligations and the determination of the timing of 
revenue recognition.  

Our audit procedures to test the Company’s determination of revenue recognition included, among 
others, reading the contractual agreement, testing management’s identification of significant terms 
for  completeness,  including  identification  of  performance  obligations,  assessing  the  terms  in  the 
agreement, and evaluating the appropriateness of management’s application of authoritative guidance 
and  existing  accounting  policies.  We  also  discussed  the  judgments  inherent  in  the  Company’s 
determination of revenue recognition, including the identification of performance obligations, with 
research and development personnel responsible for overseeing the satisfaction of the Company’s 
clinical supply obligation. 

 /s/ Ernst & Young LLP  

We have served as the Company’s auditor since 2001. 
Boston, Massachusetts  
March 1, 2021 

48 

 
 
 
 
 
IMMUNOGEN, INC. 

CONSOLIDATED BALANCE SHEETS 

In thousands, except per share amounts 

      December 31,        December 31,  

2020 

2019 

ASSETS 

Cash and cash equivalents  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 
Accounts receivable  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Unbilled receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Contract assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Non-cash royalty receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Prepaid and other current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Total current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Property and equipment, net of accumulated depreciation . . . . . . . . . . . . . . . . . . . . . . . . . .   
Operating lease right-of-use assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Other assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   

Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 

 293,856   $ 
 35  
 11  
 —  
 22,451  
 7,901  
 324,254  
 5,760  
 14,072  
 10,986  
 355,072   $ 

 176,225 
 7,500 
 1,001 
 3,631 
 15,116 
 5,425 
 208,898 
 6,993 
 15,587 
 3,784 
 235,262 

LIABILITIES AND SHAREHOLDERS’ EQUITY (DEFICIT) 

Accounts payable  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 
Accrued compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Other accrued liabilities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Convertible 4.5% senior notes, net of deferred financing costs of $7 . . . . . . . . . . . . . . . . .   
Current portion of liability related to the sale of future royalties, net of deferred 

financing costs of $319 and $635, respectively . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Current portion of operating lease liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Current portion of deferred revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Total current liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Deferred revenue, net of current portion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Operating lease liability, net of current portion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Convertible 4.5% senior notes, net of deferred financing costs of $22 . . . . . . . . . . . . . . . .   
Liability related to the sale of future royalties, net of current portion and deferred 

financing costs of $584 and $859, respectively . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Other long-term liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Total liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   

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

 9,538   $ 
 4,620  
 29,320  
 2,093  

 9,933 
 8,991 
 13,932 
 — 

 44,357  
 3,146  
 29,249  
 122,323  
 80,860  
 18,651  
 —  

 41,082  
 2,586  
 265,502  

 41,274 
 2,971 
 309 
 77,410 
 127,123 
 21,798 
 2,078 

 82,267 
 707 
 311,383 

outstanding as of December 31, 2020 and December 31, 2019, respectively . . . . . . . . .   

 —  

 — 

Common stock, $.01 par value; authorized 300,000 and 200,000 shares; issued and 

outstanding 194,998 and 150,136 shares as of December 31, 2020 and December 31, 
2019, respectively . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Additional paid-in capital . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Accumulated deficit  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Total shareholders’ equity (deficit)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   

Total liabilities and shareholders’ equity (deficit)  . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 

 1,950  
    1,419,460  
    (1,331,840) 
 89,570  
 355,072   $ 

 1,501 
    1,209,846 
    (1,287,468)
 (76,121)
 235,262 

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

49 

 
 
 
 
 
 
 
 
 
 
 
 
   
 
   
  
  
  
  
 
 
 
 
  
  
  
  
  
  
 
 
  
  
 
   
 
   
  
  
  
  
 
 
 
 
 
 
  
  
  
  
  
  
 
 
 
 
 
 
  
  
  
  
 
   
 
   
 
   
 
   
  
  
  
  
  
  
 
 
IMMUNOGEN, INC. 

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS 

In thousands, except per share amounts 

Revenues: 

License and milestone fees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 
Non-cash royalty revenue related to the sale of future royalties . . . . . . . .     
Research and development support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      
Clinical materials revenue  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      
Total revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      

 63,742   $ 
 68,529    
 28     
 —     
 132,299     

 34,788   $ 
 47,415    
 68     
 —     
 82,271     

 15,280 
 32,154 
 1,377 
 4,635 
 53,446 

Years Ended 
December 31,  
2019 

2020 

2018 

Operating expenses: 

Research and development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      
General and administrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      
Restructuring charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     
Total operating expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      
Loss from operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      
Investment income, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      
Non-cash interest expense on liability related to the sale of future 

royalties and convertible senior notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     
Interest expense on convertible senior notes . . . . . . . . . . . . . . . . . . . . . . . . . .     
Other income (expense), net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 
Basic and diluted net loss per common share  . . . . . . . . . . . . . . . . . . . . . . . . .    $ 
Basic and diluted weighted average common shares outstanding . . . . . . . . .      
Total comprehensive loss  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 

 114,592     
 38,600     
 1,487    
 154,679     
 (22,380)     
 729     

 174,456 
 114,522    
 36,746 
 38,489    
 3,693 
 21,433    
 174,444     
 214,895 
 (92,173)      (161,449)
 4,227 

 4,424    

 (16,879)   
 (95)   
 590    

 (23,107)    
 (95)    
 481     

 (10,631)
 (95)
 (895)
 (44,372)   $  (104,133)  $   (168,843)
(1.21)
(0.70)  $ 
(0.25)   $ 
 176,153     
 139,946 
 148,311    
 (44,372)   $  (104,133)  $   (168,843)

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

50 

 
 
 
 
 
 
 
 
      
     
     
   
    
   
 
 
CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY (DEFICIT) 

IMMUNOGEN, INC. 

In thousands 

  Additional  
Paid-In 
     Shares      Amount      Capital 

Common Stock 

Total 

  Accumulated  Shareholders’ 
    Equity (Deficit) 
     Deficit 
 (17,895)
 14,090 
 (168,843)

Balance at December 31, 2017 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      132,526   $   1,325   $ 1,009,362   $  (1,028,582)  $ 
Transition adjustment for ASC 606 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Issuance of common stock pursuant to the exercise of stock options and 

 14,090  
 (168,843) 

 —  
 —  

 —  
 —  

 —  
 —  

 4,301 
 162,512 
 16,445 
 1 
 361 
 10,972 
 (104,133)

 2,873 
 — 
 13,830 
 337 
 (76,121)
 (44,372)

 1,471 
 194,271 
 — 
 — 
 13,978 
 343 
 89,570 

employee stock purchase plan  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Issuance of common stock, net of issuance costs  . . . . . . . . . . . . . . . . . . . . . .   
Stock option and restricted stock compensation expense . . . . . . . . . . . . . . . . .   
Directors' deferred share units converted  . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Directors’ deferred share unit compensation . . . . . . . . . . . . . . . . . . . . . . . . . .   
Balance at December 31, 2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      149,400   $   1,494   $ 1,192,813   $  (1,183,335)  $ 
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Issuance of common stock pursuant to the exercise of stock options and 

 4,292  
 162,354  
 16,445  
 (1) 
 361  

 946  
 15,755  
 —  
 173  
 —  

 9  
 158  
 —  
 2  
 —  

 —  
 —  
 —  
 —  
 —  

 (104,133) 

 —  

 —  

 —  

employee stock purchase plan  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Restricted stock award - net of forfeitures  . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Stock option and restricted stock compensation expense . . . . . . . . . . . . . . . . .    
Directors’ deferred share unit compensation . . . . . . . . . . . . . . . . . . . . . . . . . .    
Balance at December 31, 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      150,136   $   1,501   $ 1,209,846   $  (1,287,468)  $ 
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Issuance of common stock pursuant to the exercise of stock options and 

 2,862  
 4  
 13,830  
 337  

 1,150  
 (414) 
 —  
 —  

 11  
 (4) 
 —  
 —  

 —  
 —  
 —  
 —  

 (44,372) 

employee stock purchase plan  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Issuance of common stock, net of issuance costs  . . . . . . . . . . . . . . . . . . . . . .   
Restricted stock units vested  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Restricted stock award forfeitures  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Stock option and restricted stock compensation expense . . . . . . . . . . . . . . . . .   
Directors’ deferred share unit compensation . . . . . . . . . . . . . . . . . . . . . . . . . .   
Balance at December 31, 2020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      194,998   $   1,950   $ 1,419,460   $  (1,331,840)  $ 

 1,466  
 193,826  
 (4) 
 5  
 13,978  
 343  

 458  
 44,496  
 395  
 (487) 
 —  
 —  

 5  
 445  
 4  
 (5) 
 —  
 —  

 —  
 —  
 —  
 —  
 —  
 —  

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

51 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
  
 
 
 
 
 
 
 
  
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
IMMUNOGEN, INC. 

CONSOLIDATED STATEMENTS OF CASH FLOWS 

In thousands 

Years Ended 
December 31,  
2019 

2018 

2020 

Cash flows from operating activities: 
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $   (44,372) $   (104,133)  $  (168,843)
Adjustments to reconcile net loss to net cash used for operating activities: 

Non-cash royalty revenue related to sale of future royalties . . . . . . . . . . . .   
Non-cash interest expense on liability related to sale of future royalties 

and convertible senior notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Depreciation and amortization  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
(Gain) loss on sale/disposal of fixed assets and impairment charges . . . . .   
Operating lease right-of-use asset impairment . . . . . . . . . . . . . . . . . . . . . . .   
Stock and deferred share unit compensation  . . . . . . . . . . . . . . . . . . . . . . . .   
Deferred rent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Change in operating assets and liabilities: 

Accounts receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Unbilled receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Inventory  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Contract asset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Prepaid and other current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Operating lease right-of-use assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Other assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Accounts payable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Accrued compensation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Other accrued liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Deferred revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Operating lease liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Net cash used for operating activities  . . . . . . . . . . . . . . . . . . . . . . . . . . .   

Cash flows from investing activities: 

Purchases of property and equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Proceeds from sale of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Net cash provided by (used for) investing activities . . . . . . . . . . . . . . . .   

Cash flows from financing activities: 

 (68,529)

 (47,415) 

 (32,154)

 23,107 
 2,101 
 (691)
 — 
 14,321 
 — 

 7,465 
 990 
 — 
 3,631 
 (2,476)
 1,515 
 (7,202)
 (819)
 (4,100)
 16,734 
 (17,323)
 (2,972)
 (78,620)

 (917)
 1,426 
 509 

 16,879  
 4,028  
 1,689  
 694  
 14,167  
 —  

 (5,799) 
 (384) 
 —  
 (3,131) 
 (963) 
 1,331  
 (75) 
 (1,045) 
 (2,189) 
 (6,146) 
 46,630  
 (2,505) 
 (88,367) 

 (2,845) 
 2,312  
 (533) 

 10,631 
 7,411 
 115 
 — 
 16,807 
 (95)

 948 
 1,963 
 1,038 
 (500)
 (1,495)
 — 
 88 
 2,667 
 323 
 3,839 
 (9,165)
 — 
    (166,422)

 (5,246)
 — 
 (5,246)

Proceeds from issuance of common stock under stock plans . . . . . . . . . .   
Proceeds from common stock issuance, net of $701 and $395 of 

 1,471 

 2,873  

 4,301 

transaction costs, respectively . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
 162,512 
Net cash provided by financing activities . . . . . . . . . . . . . . . . . . . . . . . .   
 166,813 
Net change in cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
 (4,855)
 267,107 
Cash and cash equivalents, beginning of period . . . . . . . . . . . . . . . . . . . . . . . .   
Cash and cash equivalents, end of period . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $   293,856  $   176,225   $   262,252 
Supplemental cash flow information: 

 —  
 2,873  
 (86,027) 
 262,252  

 194,271 
 195,742 
 117,631 
 176,225 

     Cash paid during the year for interest . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 

 95  $ 

 95   $ 

 95 

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

52 

 
 
 
 
 
     
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
 
 
 
 
 
  
  
  
  
  
  
  
  
  
 
 
 
  
  
  
 
 
 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
 
 
 
  
  
 
   
 
 
 
 
   
  
  
  
 
  
 
  
  
  
 
   
 
 
 
 
   
  
  
  
 
 
 
  
  
  
  
  
  
  
  
  
 
   
     
 
   
IMMUNOGEN, INC. 

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS 

AS OF DECEMBER 31, 2020 

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-drug conjugates, or ADCs. The Company has generally incurred operating losses and negative cash flows 
from operations since inception, incurred a net loss of $44.4 million during the year ended December 31, 2020, and has 
an accumulated deficit of approximately $1.3 billion as of December 31, 2020. The Company has primarily funded these 
losses through payments received from its collaborations and equity, convertible debt, and other financings. To date, the 
Company has no product revenue and management expects to continue to incur operating expenses related to research 
and development and potential commercialization of its portfolio over the next several years. 

At December 31, 2020, the Company had $293.9 million of cash and cash equivalents on hand. The Company 
anticipates that its current capital resources, inclusive of $33.6 million of net proceeds generated from an Open Market 
Sale AgreementSM in January 2021, will enable it to meet its operational expenses and capital expenditures for more than 
twelve months after these financial statements are issued. The Company may raise additional funds through equity, debt, 
or other financings or generate revenues from collaborators through a combination of upfront license payments, 
milestone payments, royalty payments, and research funding. There can be no assurance that the Company will be able 
to obtain additional equity, debt, or other financing or generate revenues from collaborators 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, complexities associated with managing 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., ImmunoGen Europe Limited, ImmunoGen BioPharma (Ireland) Limited, and Hurricane, 
LLC. 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 December 31, 2020 up through the 
date the Company issued these financial statements. Pursuant to an Open Market Sale AgreementSM under which the 
Company may issue and sell shares of its common stock, from time to time for an aggregate sales price of up to $150.0 
million, subsequent to December 31, 2020 and through the date the Company issued these financial statements, the 
Company has sold 4,544,424 shares of its common stock generating net proceeds of $33.6 million after deducting 
offering commissions and expenses. The Company did not have any other material recognized or unrecognized 
subsequent events. 

Adoption of ASC 842, Leases  

The Company adopted Accounting Standards Update (ASU) No. 2016-2, Leases (Topic 842) on January 1, 
2019, using the transition method provided by ASU No. 2018-11, Leases (Topic 842): Targeted Improvements. The 
reported results for 2019 reflect the application of ASC 842, while the reported results prior to 2019 were prepared under 

53 

the previous lease guidance of ASC 840, Leases, which is also referred to herein as “legacy GAAP” or the “previous 
guidance.” See Note J for further discussion and impact of adoption. 

Revenue Recognition  

The Company enters into licensing and development agreements with collaborators for the development of 

ADCs. The terms of these agreements contain multiple promised goods and services which may include (i) licenses, or 
options to obtain licenses, to the Company’s ADC technology, (ii) rights to future technological improvements, (iii) 
technology transfer services and other activities to be performed on behalf of the collaborative partner, and (iv) delivery 
of cytotoxic agents and/or the manufacture of preclinical and clinical materials for the collaborative partner. Payments to 
the Company under these agreements may include upfront fees, option fees, exercise fees, payments for services, 
payments for preclinical or clinical materials, payments based upon the achievement of certain milestones, and royalties 
on product sales. The Company follows the provisions of ASC 606, Revenue from Contracts with Customers, in 
accounting for these agreements. 

Revenue is recognized when a customer obtains control of promised goods or services in an amount that 
reflects the consideration which the entity expects to receive in exchange for those goods or services. In determining the 
appropriate amount of revenue to be recognized as it fulfills its obligations under the agreements, the Company performs 
the following five steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether 
the promised goods or services are performance obligations, including whether they are distinct in the context of the 
contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of 
the transaction price to the performance obligations; and (v) recognition of revenue when or as the Company satisfies 
each performance obligation.   

The Company only applies the five-step model to contracts when it is probable that the Company will collect 

the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. At contract 
inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or 
services promised within each contract and determines those that are performance obligations based on its assessment of 
whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the 
transaction price that is allocated to the respective performance obligation when or as the performance obligation is 
satisfied. 

The Company exercises judgment in assessing those promised goods and services that are distinct and thus 

representative of performance obligations. To the extent the Company identifies multiple performance obligations in a 
contract, the Company must develop assumptions that require judgment to determine the estimated standalone selling 
price for each performance obligation in order to allocate the transaction price among the identified performance 
obligations. These judgments and assumptions are discussed in further detail below. 

At December 31, 2020, the Company had the following types of material agreements with the parties identified 

below: 

•  Development and commercialization licenses, which provide the counterparty with the right to use the 
Company’s ADC technology and/or certain other intellectual property to develop and commercialize 
compounds to a specified antigen target: 

Bayer (one exclusive single-target license) 

CytomX (two exclusive single-target licenses) 

Debiopharm (one exclusive single-compound license) 

Fusion Pharmaceuticals (one exclusive single-target license) 

Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd. (one territory-specific exclusive single-
compound license) 

Novartis (five exclusive single-target licenses) 

Oxford BioTherapeutics/Menarini (one exclusive single-target license sublicensed from Amgen) 

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

Viridian (one exclusive single-target license) 

54 

•  Collaboration and license agreement to co-develop and co-commercialize a specified anticancer compound 

on established terms: 

MacroGenics 

During the year ended December 31, 2020, pursuant to notices received, the exclusive development and 
commercialization licenses granted to each of Biotest and Takeda and the collaboration and option agreement with Jazz 
were terminated. 

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 obligations under a development and commercialization license agreement generally include the license to 

the Company’s ADC technology with respect to a specified antigen target or compound, and may also include 
obligations related to rights to future technological improvements and other activities to be performed on behalf of 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 earn payments upon the achievement of certain 
milestones and royalty payments, generally until the later of the last applicable patent expiration or a fixed period of 
years after product launch. Royalty rates may vary over the royalty term depending on the Company’s intellectual 
property rights and/or the presence of comparable competing products. In the case of Debiopharm, no royalties will be 
received. In certain instances, the Company may also provide cytotoxic agents and/or clinical materials or other services 
in addition to the development and commercialization licenses. For example, the Company may provide technology 
transfer services in connection with the out-licensing of product candidates initially developed by the Company, and may 
also 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 certain 
services, achieve milestones, or become liable for royalty payments. 

In determining the performance obligations for these arrangements, management evaluates whether the license 
is distinct and has significant standalone functionality either alone or with other readily available resources 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 and ADC 
manufacturing capabilities in the general marketplace and whether technological improvements are required for the 
continued functionality of the license. If the license to the Company’s intellectual property is determined to be distinct, 
the Company recognizes revenues from non-refundable, upfront fees allocated to the license when the license is 
transferred to the customer and the customer is able to use and benefit from the license. If the license is not distinct, the 
license is combined with other goods or services into a single performance obligation and revenue is recognized over 
time. 

The Company estimates the standalone selling prices of the license and all other performance obligations based 
on market conditions, similar 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 other services to be performed on behalf of its collaborators and market rates for similar services. 

The Company recognizes revenue related to technology transfer activities and other services as the services are 

performed. The Company is generally compensated for these activities at negotiated rates that are consistent with what 
other third parties would charge. The Company records amounts recognized for research materials provided or services 
performed as a component of research and development support revenue.  

The Company may also provide cytotoxic agents and/or preclinical and clinical materials (drug substance/drug 

product) to its collaborators at negotiated prices generally consistent with what other third parties would charge. The 
Company recognizes revenue on cytotoxic agents and on preclinical and clinical materials when control transfers to the 
collaborator.  

The Company recognizes revenue related to the rights to future technological improvements over the estimated 

term of the applicable license. 

55 

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

reporting purposes are aggregated into two categories: (i) development and regulatory milestones, and (ii) 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 arrangement, the Company evaluates any development and regulatory milestone 

payments to determine whether the milestone is considered probable of being reached and estimates the amount to be 
included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal 
would not occur, the associated milestone value is included in the transaction price to be allocated; otherwise, such 
amounts are considered constrained and excluded from the transaction price. As part of its evaluation of the constraint, 
the Company considers numerous factors, including whether the achievement of the milestone is outside the control of 
the Company and contingent upon the future success of clinical trials, the collaborator’s efforts, or the receipt of 
regulatory approval. At the end of each subsequent reporting period, the Company re-evaluates the probability of 
achievement of such development or regulatory milestones and any related constraint, and if necessary, adjusts the 
estimate of the transaction price. In addition, the Company evaluates whether the achievement of each milestone 
specifically relates to the Company’s efforts to satisfy a performance obligation or transfer a distinct good or service 
within a performance obligation. If the achievement of a milestone is considered a direct result of the Company’s efforts 
to satisfy a performance obligation or transfer a distinct good or service and the receipt of the payment is based upon the 
achievement of the milestone, the associated milestone value is allocated to that distinct good or service. If the milestone 
payment is not specifically related to the Company’s effort to satisfy a performance obligation or transfer a distinct good 
or service, the amount is allocated to all performance obligations using the relative standalone selling price method. 
Amounts allocated to a satisfied performance obligation are recognized as revenue, or as a reduction of revenue, in the 
period in which the transaction price changes. 

For development and commercialization license agreements that include sales-based royalties, including 
milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the 
royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the 
performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied) in 
accordance with the royalty recognition constraint. Under the Company’s development and commercialization license 
agreements, except for the Debiopharm license, the Company receives royalty payments based upon its licensees’ net 
sales of covered products. Generally, under the development and commercialization agreements, the Company receives 
royalty reports and payments from its licensees approximately one quarter in arrears. The Company estimates the 
amount of royalty revenue to be recognized based on historical and forecasted sales and/or sales information from its 
licensees if available.  

Collaboration and Option Agreements/Right-to-Test Agreements 

The Company’s right-to-test agreements provide collaborators the right to test the Company’s ADC technology 

for a defined period of time through a research, or right-to-test, license. Under both right-to-test agreements and 
collaboration and option agreements, collaborators may (a) “take” options, for a defined period of time, to specified 
targets and (b) 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 the opt-in 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”), (iii) after providing services at the collaborator’s request at negotiated prices, 
which are generally consistent with what other third parties would charge, or (iv) upon some combination of all of these 
fees. 

The accounting for collaboration and option agreements and right-to-test agreements is dependent on the nature 

of the options granted to the collaborative partner. Options are considered distinct performance obligations if they 
provide a collaborator with a material right. Factors that are considered in evaluating whether options convey a material 
right 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 fair value of the licenses, and the additional 
financial commitments or economic penalties imposed on the collaborator as a result of exercising the options. As of 
December 31, 2020, all option and right-to-test agreements have expired or terminated.   

If the Company concludes that an option provides the customer a material right, and therefore is a separate 
performance obligation, the Company then determines the estimated standalone selling price of the option using the 

56 

following inputs: (a) estimated fair value of the license underlying each option, (b) the amount the partner would pay to 
exercise the option to obtain the license, and (c) probability of exercise.  

The Company does not 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. 

Upfront payments on development and commercialization licenses may be recognized upon delivery of the 

license if facts and circumstances dictate that the license is distinct from the other promised goods and services. 

In determining whether a collaboration and option agreement is within the scope of ASC 808, Collaborative 

Arrangements, management evaluates the level of involvement of both companies in the development and 
commercialization of the products to determine if both parties are active participants and if both parties are exposed to 
risks and rewards dependent on the commercial success of the licensed products. If the agreement is determined to be 
within the scope of ASC 808 and not representative of a vendor-customer relationship, the Company segregates the 
research and development activities and the related cost sharing arrangement. Payments made by the Company for such 
activities are recorded as research and development expense and reimbursements received from the partner are 
recognized as an offset to research and development expense.  

Transaction Price Allocated to Remaining Performance Obligations 

Deferred revenue under ASC 606 represents the portion of the transaction price received under various 

contracts for which work has not been performed (or has been partially performed) and includes unexercised contract 
options that are considered material rights. As of December 31, 2020, the aggregate amount of the transaction price 
allocated to remaining performance obligations comprising deferred revenue was $110.1 million. The Company expects 
to recognize revenue on approximately 27%, 65%, and 8% of the remaining performance obligations over the next 12 
months, 13 to 60 months, and 61 to 120 months, respectively, however, it does not control when or if any collaborator 
will terminate existing development and commercialization licenses. 

Contract Balances from Contracts with Customers 

The following tables present changes in the Company’s contract assets and contract liabilities during the years 

ended December 31, 2020 and 2019 (in thousands): 

Year ended December 31, 2020 
Contract asset . . . . . . . . . . . . . . . . .    $ 
Contract liabilities (deferred 

Balance at 
  December 31, 2019  

Additions 

Deductions 

 3,631    $ 

 —   $ 

 (8,000)  $ 

Impact of Netting    December 31, 2020 
 — 

 4,369    $ 

revenue) . . . . . . . . . . . . . . . . . . . .    $ 

 127,432    $ 

 42,050   $ 

 (63,742)  $ 

 4,369    $ 

 110,109 

Year ended December 31, 2019 
Contract asset . . . . . . . . . . . . . . . . .    $ 
Contract liabilities (deferred 

Balance at 
  December 31, 2018 

Additions 

Deductions 

 500    $ 

 8,000   $ 

 (500)  $ 

Impact of Netting    December 31, 2019 
 3,631 

 (4,369) $ 

revenue) . . . . . . . . . . . . . . . . . . . .    $ 

 80,802    $ 

 65,816   $ 

 (14,817)  $ 

 (4,369) $ 

 127,432 

During the years ended December 31, 2020, 2019, and 2018 the Company recognized the following revenues as 

a result of changes in contract asset and contract liability balances in the respective periods (in thousands):  

2020 

Year Ended  
December 31,  
2019 

2018 

Revenue recognized in the period from: 
Amounts included in contract liabilities at the beginning of the 

period  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 
Performance obligations satisfied in previous periods . . . . . . . . . . .    $ 

 61,872    $ 
 —  $ 

 14,817    $ 
 12,672    $ 

 14,139 
 1,476 

During 2020, the Company recognized $60.5 million of previously deferred license revenue upon Jazz’s opt-out 

of its right to the last remaining license under the agreement and $3.2 million of upfront fees previously received from 
other partners, of which $1.4 million was included in contract liabilities at the beginning of 2020. A $40.0 million 
upfront payment received in 2020 pursuant to a license agreement executed with Huadong was recorded as deferred  

57 

Balance at 

Balance at 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
   
 
   
 
revenue and none of this amount was recognized as revenue during 2020. Additionally, a contract asset of $3.6 million, 
net of $4.4 million in related contract liabilities, was recorded for two probable milestones in 2019 pursuant to license 
agreements with CytomX and Novartis, which were subsequently achieved and paid during 2020.  

The Company recorded the following during the year ended December 31, 2019: (i) license and milestone fee 

revenue of $7.7 million for probable development milestones pursuant to license agreements with CytomX and Novartis, 
with another $0.3 million deferred which represents the amount allocated to future rights to technological improvements; 
a $3.6 million contract asset was recorded in December 2019 related to these probable milestones, net of a $4.4 million 
reduction in related contract liabilities; (ii) a $5 million regulatory milestone payment earned under its license agreement 
with Genentech, a member of the Roche Group; the full amount of the milestone was recognized as revenue in the period 
as the amount allocated to future rights to technological improvements was not material; (iii) $14.5 million of previously 
deferred license revenue recognized upon the opt-out of the right to execute a license by Jazz; (iv) $65.2 million was 
recorded as deferred revenue as a result of a sale of the Company’s residual rights to receive royalty payments on 
commercial sales of Kadcyla ® (ado-trastuzumab emtansine) as discussed in Note F; and (v) $0.3 million of revenue 
previously deferred related to numerous collaborators’ rights to technological improvements. Additionally, $7.3 million 
of a $7.5 million upfront payment invoiced to CytomX pursuant to a license agreement executed in December 2019 was 
recorded as license and milestone fee revenue upon delivery of the license and $0.2 million was deferred until delivery 
of certain materials. 

As a result of adoption of ASC 606, a contract asset of $5.0 million was recorded for a probable milestone 

which was subsequently earned and paid during the year ended December 31, 2018. Additionally the Company recorded 
the following during 2018: (i) a contract asset and related revenue of $0.5 million for a probable milestone pursuant to a 
license agreement with Fusion Pharmaceuticals, which was subsequently paid in 2019; (ii) a $1 million development 
milestone earned under a sublicense agreement with Oxford BioTherapeutics Ltd. as license and milestone fee revenue, 
which was included in accounts receivable as of December 31, 2018; (iii) $10.9 million of revenue previously deferred, 
with a net reduction in deferred revenue of $5.9 million due to contract asset and contract liability netting as a result of 
Takeda not executing a second license it had available, or extending or expanding its right-to-test agreement; (iv) $0.8 
million of revenue previously deferred upon completion of Debiopharm and another collaborator’s performance 
obligations; (v) $2.1 million of revenue previously deferred related to numerous collaborators’ rights to technological 
improvements; and (vi) $0.3 million of revenue previously deferred upon shipment of clinical materials to a partner 
which is included in clinical material revenue.  

The timing of revenue recognition, billings, and cash collections results in billed receivables, unbilled 
receivables, contract assets, and contract liabilities on the consolidated balance sheets. When consideration is received, 
or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer 
under the terms of a contract, a contract liability is recorded (under the caption deferred revenue). Contract liabilities are 
recognized as revenue after control of the products or services is transferred to the customer and all revenue recognition 
criteria have been met. 

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 December 31, 2020 
or 2019. 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. 

Cash and Cash Equivalents 

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

cash equivalents. As of December 31, 2020 and 2019, the Company held $293.9 million and $176.2 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.  

Non-cash Investing Activities 

The Company had $0.7 million of accrued capital expenditures as of December 31, 2020 which have been 

treated as a non-cash investing activity and, accordingly, not reflected in the consolidated statement of cash flows. The 
Company had no accrued capital expenditures as of December 31, 2019. 

58 

Fair Value of Financial Instruments 

ASC 820, Fair Value Measurement, defines fair value, establishes a framework for measuring fair value in 
accordance with accounting principles generally accepted in the U.S., and provides for disclosures about fair value 
measurements. Fair value is defined under ASC 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 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: 

•  Level 1—Quoted prices in active markets for identical assets or liabilities. 
•  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 other inputs that are 
observable or can be corroborated by observable market data for substantially the full term of the assets or 
liabilities. 

•  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 December 31, 2020 and 2019, the Company held certain assets that are required to be measured at fair 
value on a recurring basis. The following tables represent the fair value hierarchy for the Company’s financial assets 
measured at fair value on a recurring basis as of each date (in thousands): 

Cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $  194,525   $ 

 194,525   $ 

 —   $ 

 — 

Fair Value Measurements at December 31, 2020 Using 

  Quoted Prices in   
  Active Markets for  

Significant Other   Unobservable 

Significant 

Identical Assets    Observable Inputs  

Inputs 

Total 

(Level 1) 

(Level 2) 

(Level 3) 

Fair Value Measurements at December 31, 2019 Using 

  Quoted Prices in   
  Active Markets for  

Significant Other   Unobservable 

Significant 

Identical Assets    Observable Inputs  

Inputs 

Total 

(Level 1) 

(Level 2) 

(Level 3) 

Cash equivalents  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $  163,674   $ 

 163,674      $ 

 —     $ 

 — 

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 receivable, 
contract assets, non-cash royalty receivable, prepaid and other current assets, accounts payable, accrued compensation, 
and other accrued liabilities approximate fair value due to their short-term nature. The gross carrying amount and 
estimated fair value of the convertible 4.5% senior notes was $2.1 million and $4.3 million, respectively, as of 
December 31, 2020 compared to $2.1 million and $3.0 million, respectively, as of December 31, 2019. The estimated 
fair value per $1,000 convertible notes remaining as of December 31, 2020 increased compared to December 31, 2019 
due primarily to an increase in the Company’s stock price. The fair value of the convertible notes is influenced by 
interest rates, the Company’s stock price and stock price volatility, and by prices observed in trading activity for the 
convertible notes. However, because there have been no trades involving the convertible notes since September 2019, 
the fair value as of December 31, 2019 and December 31, 2020 uses Level 3 inputs. 

 Unbilled Receivable 

Unbilled receivable primarily represents research funding earned based on actual resources utilized and external 

expenses incurred under certain of the Company’s collaborator agreements. 

Clinical Trial Accruals 

Clinical trial expenses are a significant component of research and development expenses, and the Company 

outsources a significant portion of these activities to third parties. Third-party clinical trial expenses include investigator 
fees, site costs (patient cost), clinical research organization costs, and costs for central laboratory testing and data 
management. The accrual for site and patient costs includes inputs such as estimates of patient enrollment, patient cycles 

59 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    
     
     
    
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    
     
     
    
incurred, clinical site activations, and other pass-through cost. These inputs are required to be estimated due to a lag in 
receiving the actual clinical information from third parties. Payments for these activities are based on the terms of the 
individual arrangements, which may differ from the pattern of costs incurred, and are reflected on the consolidated 
balance sheets as prepaid assets or accrued clinical trial costs. These third-party agreements are generally cancelable, and 
related costs are recorded as research and development expenses as incurred. Non-refundable advance clinical payments 
for goods or services that will be used or rendered for future R&D activities are recorded as a prepaid asset and 
recognized as expense as the related goods are delivered or the related services are performed. The Company also 
records accruals for estimated ongoing clinical research and development costs. When evaluating the adequacy of the 
accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices 
received, and contracted costs. Significant judgments and estimates may be made in determining the accrued balances at 
the end of any reporting period. Actual results could differ from the estimates made by the Company. The historical 
clinical accrual estimates made by the Company have not been materially different from the actual costs.  

Leases 

Effective January 1, 2019, the Company adopted ASU 2016-2, the details of which are further discussed in Note 
J. The Company determines if an arrangement is a lease at inception. Operating leases include right-of-use (ROU) assets 
and operating lease liabilities (current and non-current), which are recorded in the Company’s consolidated balance 
sheets. Single payment capital leases for equipment that are considered finance leases are included in property and 
equipment in the Company’s consolidated balance sheets. As the single payment obligations have all been made, there is 
no related liability recorded.   

ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities 
represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and 
liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The 
Company uses the implicit rate when readily determinable. As a number of the Company’s leases do not provide an 
implicit rate, the Company uses an incremental borrowing rate applicable to the Company based on the information 
available at the commencement date in determining the present value of lease payments. As the Company has no 
existing or proposed collateralized borrowing arrangements, to determine a reasonable incremental borrowing rate, the 
Company considers collateral assumptions, the lease term, the Company’s current credit risk profile, and rates for 
existing borrowing arrangements for comparable peer companies. The operating lease ROU assets were netted against 
any lease incentive and straight-line lease liability balances at January 1, 2019 upon adoption of ASC 842. The Company 
accounts for the lease and fixed non-lease components as a single lease component. The Company’s lease terms may 
include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. 
Lease expense for operating lease payments is recognized on a straight-line basis over the lease term. 

Other Accrued Liabilities 

Other accrued liabilities consisted of the following at December 31, 2020 and 2019 (in thousands): 

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

2020 
 15,576  $ 
 11,401 
 1,200 
 39 
 319 
 785 
 29,320  $ 

2019 

 5,188 
 6,418 
 1,274 
 314 
 180 
 558 
 13,932 

  December 31,       December 31,  

Accrued contract payments included in the table above primarily relate to external manufacturing, regulatory, 

and quality-related services. The increase in the balance as of December 31, 2020 compared to prior year is driven 
primarily by external manufacturing expenses related to the potential commercial launch of mirvetuximab. 

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) external 
manufacturing operations and, prior to 2019, internal manufacturing operations, which also  

60 

 
 
 
 
 
 
 
 
 
    
 
  
  
  
  
  
  
  
  
  
  
included 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. 

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 . . . . . . . . . . . . . . . . . . . . . . . . .         5 years 
Computer hardware and software . . . . . . . . . . . . . . . . . . .      3 years 
Furniture and fixtures . . . . . . . . . . . . . . . . . . . . . . . . . . . .      5 years 
Leasehold improvements  . . . . . . . . . . . . . . . . . . . . . . . . .      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. 

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 net gains (losses) of $0.7 million, $(1.7) million, and $(0.1) million 
related to impairment charges and the sale/disposal of certain furniture and equipment during the years ended 
December 31, 2020, 2019, and 2018, respectively.  

Impairment of Long-Lived Assets 

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 if impairment indicators are present. The Company evaluates the realizability of its long-lived assets 
based on cash flow expectations for the related asset. Any write-downs to fair value are treated as permanent reductions 
in the carrying amount of the assets. Accordingly, during the year ended December 31, 2019, the Company recorded a 
$2.5 million asset impairment charge resulting from restructuring activities, the details of which are further discussed in 
Note I. Based on this evaluation, except for the impairment recognized during 2019, the Company believes that none of 
the Company’s remaining 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”). Shares of the Company’s restricted stock 
participate 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, convertible notes, and restricted stock that are outstanding during the period, except where such 
non-participating securities would be anti-dilutive. 

61 

 
 
 
 
 
 
 
 
The Company’s common stock equivalents, as calculated in accordance with the treasury-stock method for the 
options and unvested restricted stock and the if-converted method for the convertible notes, are shown in the following 
table (in thousands): 

Options outstanding to purchase common stock, shares issuable under 

the employee stock purchase plan, and unvested restricted stock/units 
at end of period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    

Common stock equivalents under treasury stock method for options, 

shares issuable under the employee stock purchase plan, and unvested 
restricted stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     
Shares issuable upon conversion of convertible notes at end of period  . .    
Common stock equivalents under if-converted method for convertible 

Years Ended December 31, 
2019 

2020 

2018 

 20,873 

 14,815 

 17,380 

 1,301 
 501 

 1,020 
 501 

 3,001 
 501 

notes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    

 501 

 501 

 501 

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 December 31, 2020, the Company is authorized to grant future awards under three employee share-based 
compensation plans, which are the ImmunoGen, Inc. 2018 Employee, Director and Consultant Equity Incentive Plan, or 
the 2018 Plan, the Employee Stock Purchase Plan, or ESPP, and the ImmunoGen Inducement Equity Incentive Plan, or 
the Inducement Plan. At the annual meeting of shareholders on June 20, 2018, the 2018 Plan was approved and provides 
for the issuance of Stock Grants, the grant of Options, and the grant of Stock-Based Awards for up to 7,500,000 shares 
of the Company’s common stock, as well as up to 19,500,000 shares of common stock which represent awards granted 
under the previous stock option plans, the ImmunoGen, Inc. 2016 and 2006 Employee, Director and Consultant Equity 
Incentive Plans, or the 2016 and 2006 Plans, that forfeit, expire, or cancel without delivery of shares of common stock or 
which resulted in the forfeiture of shares of common stock back to the Company subsequent to June 19, 2018. The 
Inducement Plan was approved the by Board of Directors in December 2019, and pursuant to subsequent amendments, 
provides for the issuance of non-qualified option grants for up to 1,500,000 shares of the Company’s common stock. 
Options awarded under the two plans 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 718, “Compensation—Stock Compensation.” Pursuant to 

ASC 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. 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 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. 

Dividend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Volatility  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Risk-free interest rate  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Expected life (years) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  

2020 
None 
85.07% 
1.21% 
6.0 

December 31, 
2019 
None 
76.67% 
2.20% 
6.0 

2018 
None 
71.02% 
2.73% 
6.0 

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

during the years ended December 31, 2020, 2019, and 2018, were $3.28, $2.81, and $6.70 per share, respectively. 

62 

 
 
 
    
   
   
 
 
 
 
 
 
 
 
 
 
     
     
     
 
 
 
 
 
 
 
 
 
 
 
 
A summary of option activity under the option plans for 2020 is presented below (in thousands, except 

weighted-average data): 

Outstanding at December 31, 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Forfeited/Canceled  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Outstanding at December 31, 2020 . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Outstanding at December 31, 2020—vested or unvested and 

expected to vest  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Exercisable at December 31, 2020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    

17,830    $ 
6,983    $ 

Number 
of Stock 
Options 
13,518    $ 
7,421     
(336)    
(2,205)    
18,398     

     Weighted- 
Average 
Exercise 
Price 

      Weighted-       

Average    Aggregate 
Intrinsic 
Value 

  Remaining  
  Life in Yrs.  

7.53   
4.60   
2.94   
10.28   
6.10   

6.15   
8.15   

7.66    $  31,110 

7.61    $  29,990 
5.82    $   9,222 

In September 2018, the Company granted 295,200 performance-based stock options to certain employees that 

will vest in two equal installments upon the achievement of specified performance goals. At December 31, 2020, 
128,700 of these options are still outstanding. In the year ended December 31, 2020, the Company issued 2.6 million 
additional performance stock options that will vest in four installments upon the achievement of specified performance 
goals. The Company determined it is not currently probable that any of these performance goals will be achieved and, 
therefore, no expense has been recorded to date. The fair value of the performance-based options that could be expensed 
in future periods is $9.4 million. 

A summary of restricted stock and restricted stock unit activity under the option plans as for 2020 is presented 

below (in thousands, except weighted-average data): 

Unvested at December 31, 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     
Vested . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Unvested at December 31, 2020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    

Weighted- 

Number of   
Restricted 

  Average Grant 
      Stock Shares      Date Fair Value 
2.97 
2.60 
3.62 
2.47 

1,297    $ 
 (749) 
 (487) 

61    $ 

In 2016, 2017, and 2019, the Company granted shares of performance-based restricted common stock to certain 

employees of the Company. All but 57,400 of these granted shares have since been forfeited. The restrictions on these 
shares will lapse in three equal installments upon the achievement of specified performance goals. The Company 
determined it is not currently probable that these performance goals will be achieved and, therefore, no expense has been 
recorded to date. The fair value of the performance-based shares that could be expensed in future periods is $0.1 million. 

In June 2018, the Company's Board of Directors, with shareholder approval, adopted the Employee Stock 

Purchase Plan. Following the automatic share increase on January 1, 2021 under the ESPP’s “evergreen” provision, an 
aggregate of 2,000,000 shares of common stock have been reserved for issuance under the ESPP. Under the ESPP, 
eligible participants purchase shares of the Company's common stock at a price equal to 85% of the lesser of the closing 
price of the Company's common stock on the first business day and the final business day of the applicable plan 
purchase period. Plan purchase periods are six months and begin on January 1 and July 1 of each year, with purchase 
dates occurring on the final business day of the given purchase period. The fair value of each ESPP award is estimated 
on the first day of the offering period using the Black-Scholes option-pricing model. The Company recognizes share-
based compensation expense equal to the fair value of the ESPP awards on a straight-line basis over the offering period. 
During 2020 and 2019, approximately 122,000 and 356,000 shares, respectively, were issued to participating employees 
at fair values ranging from $1.20 to $2.14 per share.  

Stock compensation expense related to stock options and restricted stock awards granted under the option plans 
and the ESPP was $14.0 million, $13.8 million, and $16.4 million during the years ended December 31, 2020, 2019 and 
2018, respectively. As of December 31, 2020, the estimated fair value of unvested employee awards was $17.8 million. 
The weighted-average remaining vesting period for these awards is approximately 2.6 years. Also included in stock and 
deferred stock unit compensation expense in the consolidated statements of cash flows for the years ended December 31, 
2020, 2019, and 2018 is $0.4 million, $0.3 million, and $0.4 million, respectively, of expense recorded for directors’ 
deferred share units, the details of which are discussed in Note H. 

63 

 
 
 
 
 
 
 
 
 
 
 
 
    
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
 
   
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
A summary of option activity for options vested during the years ended December 31, 2020, 2019, and 2018 is 

presented below (in thousands): 

Total fair value of options vested . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     $
Total intrinsic value of options exercised . . . . . . . . . . . . . . . . . . . . . . . . . .    
Cash received for exercise of stock options  . . . . . . . . . . . . . . . . . . . . . . . .   

Years Ended December 31, 
2019 
 13,747   $
 556  
 2,873  

2020 
 11,465   $ 
 746  
 1,471  

2018 

 7,496  
 3,787  
 4,301  

Comprehensive Loss 

The Company presents comprehensive loss in accordance with ASC 220, Comprehensive Income. 

Comprehensive loss is comprised of the Company’s net loss for all periods presented. 

Segment Information 

During all periods presented, the Company continued to operate in one reportable business segment under the 

management approach of ASC 280, Segment Reporting, which is the business of the discovery and development of 
ADCs for the treatment of cancer. 

The percentages of revenues recognized from significant customers of the Company in the years ended 

December 31, 2020, 2019, and 2018 are included in the following table: 

Collaborative Partner: 
CytomX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     
Roche . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Takeda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Jazz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    

Years Ended December 31,  
2019 
13% 
64% 
-% 
18% 

2018 
8% 
60% 
23% 
-% 

2020 
-% 
53% 
1% 
46% 

There were no other customers of the Company with significant revenues in the periods presented. 

Recently Adopted Accounting Pronouncements 

In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying 

the Interaction between Topic 808 and Topic 606, which clarifies that certain transactions between participants in a 
collaborative arrangement should be accounted for under ASC 606 when the counterparty is a customer. In addition, 
ASU 2018-18 adds unit-of-account guidance to ASC 808 in order to align this guidance with ASC 606 and also 
precludes an entity from presenting consideration from a transaction in a collaborative arrangement as revenue from 
contracts with customers if the counterparty is not a customer for that transaction. This guidance is effective for annual 
reporting periods beginning after December 15, 2019, including interim periods within those annual reporting periods. 
The Company adopted the standard on January 1, 2020, and it did not have a material effect on the Company’s 
consolidated financial statements. 

In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments, to 

require financial assets carried at amortized cost to be presented at the net amount expected to be collected based on 
historical experience, current conditions, and forecasts. The ASU is effective for interim and annual periods beginning 
after December 15, 2019. Adoption of the ASU is on a modified retrospective basis. The Company adopted the standard 
on January 1, 2020, and it did not have a material effect on the Company’s consolidated financial statements. 

Recently issued accounting pronouncements, not yet adopted 

In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for 
Income Taxes, which is intended to simplify the accounting for income taxes. ASU 2019-12 removes certain exceptions 
to the general principles in ASC 740 and also clarifies and amends existing guidance to improve consistent application. 
The new standard will be effective beginning January 1, 2021. The Company does not expect the adoption of this 
standard to have a material effect on its financial position or results of operations. 

No other recently issued or effective ASUs had, or are expected to have, a material effect on the Company's 

results of operations, financial condition, or liquidity. 

64 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
     
    
    
 
 
  
  
 
  
  
 
 
 
 
 
 
 
 
 
 
    
     
     
 
 
 
 
C. 

Agreements 

Significant Collaborative Agreements 

Roche 

In 2000, the Company granted Genentech, now a unit of Roche, an exclusive development and 

commercialization 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 2013, the HER2-targeting ADC, Kadcyla, was 
approved for marketing in the U.S., Japan, and the European Union, or EU. Roche has 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 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 development and regulatory milestone payments, plus royalties on the commercial sales of Kadcyla or 
any other resulting products. Through December 31, 2020, the Company has received and recognized $39.0 million in 
milestone payments related to Kadcyla. On May 3, 2019, Roche notified the Company that the FDA approved Kadcyla 
for adjuvant (after surgery) treatment of people with HER2-positive early breast cancer who have residual invasive 
disease after neoadjuvant (before surgery) taxane and Herceptin® (trastuzumab)-based treatment, resulting in a $5 
million regulatory milestone payment to the Company for a first extended indication, which is included in license and 
milestone fees for the year ended December 31, 2019. The next and final potential milestone the Company will be 
entitled to receive will be a $5 million regulatory milestone for marketing approval of Kadcyla for a second extended 
indication as defined in the agreement. 

The Company receives royalty reports and payments related to sales of Kadcyla from Roche one quarter in 

arrears. In accordance with the Company’s revenue recognition policy, $68.5 million, $47.4 million, and $32.2 million 
of non-cash royalties on net sales of Kadcyla were recorded and included in royalty revenue for the years ended 
December 31, 2020, 2019, and 2018. Kadcyla sales occurring after January 1, 2015 are covered by a royalty purchase 
agreement whereby the associated cash, except for a residual tail, would have been remitted to Immunity Royalty 
Holdings, L.P, (IRH). In January 2019, the Company announced the sale of its residual tail to OMERS, the defined 
benefit pension plan for municipal employees in the Province of Ontario, Canada, for $65.2 million, net of fees, as 
discussed further in Note F. Simultaneously, OMERS purchased IRH’s right to the royalties the Company previously 
sold as described above, thereby obtaining the rights to 100% of the royalties received from that date on. 

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, now 
expired, 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 and regulatory milestones—
$28 million; and sales milestones—$10 million. The Company has not received any milestone payments from these 
agreements through December 31, 2020. 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.  

Amgen/Oxford BioTherapeutics 

Under a now-expired right-to-test agreement established in 2000, the Company granted Amgen four exclusive 

development and commercialization licenses, for which the Company received an exercise fee of $1 million for each 
license taken. Three of the four licenses have since been terminated by Amgen, and Amgen has sublicensed its rights 
under the one remaining license to Oxford BioTherapeutics Ltd. (OBT).  

For the remaining development and commercialization license, 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 are categorized as follows: development and regulatory milestones—$29 million; and sales milestones—
$5 million. Amgen (or its sublicensee(s)) is responsible for the manufacturing, development, and marketing of any 
products resulting from this development and commercialization license. Through December 31, 2020, the Company has 
received and recognized an aggregate of $4 million in milestone payments for compounds covered under this agreement 
now or in the past. The next potential milestone the Company will be entitled to receive under the remaining license will 
be a development milestone for the first dosing of a patient in a U.S. Phase 2 clinical trial, which will result in a 
$3 million payment being due.  

65 

Bayer  

In 2008, the Company granted Bayer an exclusive development and commercialization license to the 

Company’s maytansinoid ADC technology for use with antibodies or other proteins that target mesothelin. The 
Company received a $4 million upfront payment upon execution of the agreement. For each compound developed and 
marketed by Bayer 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 and regulatory milestones—$60.5 million; and sales milestones—$110 million. Through 
December 31, 2020, the Company has received and recognized an aggregate of $13 million in milestone payments under 
this agreement. The next potential milestone the Company will be entitled to receive will be either a development 
milestone for commencement of a pivotal clinical trial for a second indication for anetumab ravtansine which will result 
in a $2 million payment being due or a regulatory milestone for filing of regulatory approval for its first indication for 
anetumab ravtansine which will result in a $6 million payment being due. Bayer is responsible for the research, 
development, manufacturing, and marketing of any products resulting from the license.   

Novartis 

The Company granted Novartis exclusive development and commercialization licenses to the Company’s 

maytansinoid and IGN ADC technology for use with antibodies to six specified targets under a now-expired right-to-test 
agreement established in 2010. The Company received a $45 million upfront payment in connection with the execution 
of the right-to-test agreement in 2010, $8.5 million in extension and amendment fees, and an exercise fee of $1 million 
for each of the six licenses taken. In May 2018, Novartis terminated one of its six licenses. As a result, the Company 
recorded the remaining unrecognized $1.0 million balance of the upfront payment that had been allocated to future 
performance obligations under this license as revenue, which is included in license and milestone fees for the year ended 
December 31, 2018. 

For the remaining development and commercialization licenses, the Company is entitled to receive 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 and regulatory milestones—$99.5 million; and sales milestones—
$100 million. In 2015 and 2016, Novartis initiated Phase 1 testing of three of its five product candidates, triggering a $5 
million development milestone payment to the Company with each event. Novartis later discontinued clinical testing of 
these three products. In December 2019, a development milestone related to dosing a first patient in a Phase 1 clinical 
trial for a separate licensed product became probable of being attained. Accordingly, $4.7 million of the $5.0 million 
milestone that was allocated to the delivered license was recorded as revenue and is included in license and milestone 
fees for the year ended December 31, 2019, and $0.3 million that was allocated to future technological improvements 
was deferred and will be recognized as revenue ratably over the estimated term of the license. In September 2020, 
Novartis enrolled its first patient in the aforementioned Phase 1 clinical trial and remitted the $5.0 million milestone 
payment to the Company. The next potential payment the Company could receive would be either a $7.5 million 
development milestone for commencement of a Phase 2 clinical trial or a $5 million development milestone for 
commencement of a Phase 1 clinical trial. Novartis is responsible for the manufacturing, development, and marketing of 
any products resulting from this agreement. 

CytomX 

In 2016, the Company granted CytomX an exclusive development and commercialization license to the 
Company’s maytansinoid ADC technology for use with Probodies™ that target CD166 under a now expired reciprocal 
right-to-test agreement. The Company neither received nor made an upfront cash payment in connection with the 
execution of the right-to-test agreement or the license agreement. An amendment of the right-to-test agreement executed 
simultaneously with the license granted CytomX the right, for a specified period of time, to substitute the specified target 
with another as yet unspecified target. Accordingly, the revenue associated with this license was deferred until the 
expiration of that substitution right in January 2017, whereupon the Company recognized $12.7 million of the $13 
million of arrangement consideration allocated to the development and commercialization license. With respect to the 
development and commercialization license granted to 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 and regulatory milestones—$60 million; and sales milestones—$100 million. In 
June 2017, CytomX enrolled its first patient in a Phase 1 clinical trial for its product candidate, CX-2009, triggering a $1 
million development milestone payment. In December 2019, a development milestone related to dosing of a first patient 
in a Phase 2 clinical trial became probable of being attained, which resulted in $3.0 million of license and milestone fee 
revenue being recorded in 2019. In February 2020, CytomX notified the Company that it had enrolled its first patient in 
the aforementioned Phase 2 clinical trial. The next payment the Company could receive would be a $6.0 million 

66 

development milestone payment with commencement of a Phase 3 clinical trial. CytomX is responsible for the 
manufacturing, development, and marketing of any products resulting from the development and commercialization 
license taken by CytomX under this collaboration.  

Costs directly attributable to the CytomX collaborative agreement are comprised of compensation and benefits 
related to employees who provided research and development services on behalf of CytomX as well as costs of clinical 
materials sold. Indirect costs are not identified to individual collaborators. For the year ended December 31, 2018, the 
costs related to the research and development services and clinical materials sold amounted to $0.2 million and $3.5 
million. There were no similar costs recorded subsequently. 

In 2017, the Company took exclusive development and commercialization licenses to CytomX’s proprietary 

antibody-masking (Probody) technology for use with Probodies that target two specified targets under the same 
reciprocal right-to-test agreement. The Company terminated one of these licenses for convenience prior to the end of 
2017 and terminated the second license in December 2019 in connection with the grant of the EpCAM license to 
CytomX discussed further below. No upfront cash payments were made by the Company with the execution of these 
license agreements.  

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 that were 
received from CytomX were recorded as research and development expenses as incurred. 

In December 2019, the Company granted CytomX an exclusive development and commercialization license to 

maytansinoid and IGN ADC technology for use with Probodies™ that target EpCAM. Pursuant to the license agreement, 
in January 2020, the Company received a $7.5 million upfront payment, of which $7.3 million was recorded as license 
and milestone fee revenue upon delivery of the license to CytomX in December 2019 and $0.2 million was deferred until 
delivery of certain materials as these performance obligations were determined to be distinct. The Company is also 
entitled to receive up to a total of $355 million in milestone payments plus royalties on the commercial sales of any 
resulting product. The total milestones are categorized as follows: development and regulatory milestones—
$205 million; and sales milestones—$150 million. CytomX is responsible for the manufacturing, product development, 
and marketing of any products resulting from this license.  

Fusion 

In December 2016, the Company entered into an exclusive license agreement to a specified target with Fusion 

Pharmaceuticals Inc. The Company is entitled to receive up to a total of $50 million in milestone payments plus royalties 
on the commercial sales of any resulting products. The total milestones are categorized as follows: development and 
regulatory milestones—$15 million; and sales milestones—$35 million. During the year ended December 31, 2018, a 
development milestone related to dosing of a first patient in a Phase I clinical trial became probable of being attained, 
which resulted in a $0.5 million contract asset and the related license and milestone fee revenue being recorded in that 
year. It was subsequently paid in 2019. The next potential milestone payment the Company will be entitled to receive 
will be a $1.5 million development milestone payment with the initiation of a Phase II clinical trial. Fusion is responsible 
for the manufacturing, development, and marketing of any products resulting from the license. 

Debiopharm 

In May 2017, Debiopharm International SA (Debiopharm) acquired the Company’s IMGN529 program, a 

clinical-stage anti-CD37 ADC for the treatment of patients with B-cell malignancies, such as non-Hodgkin lymphomas 
(NHL). Under the terms of the Exclusive License and Asset Purchase agreement, the Company received a $25 million 
upfront payment for specified assets related to IMGN529, a paid-up license to the Company’s ADC technology and a $5 
million milestone payment upon substantial completion of the transfer of ImmunoGen technologies related to the 
program (technology transfer). This technology transfer was completed in the fourth quarter of 2017, and $4.5 million 
was received for this milestone in December 2017, and the $0.5 million balance in January 2018 upon delivery of the 
final materials related to the transfer. Accordingly, the Company recorded $0.5 million and $29.5 million of license and 
milestone fee revenue in 2018 and 2017, respectively. In addition, ImmunoGen is eligible for a second success-based 
milestone payment of $25 million upon IMGN529 entering a Phase 3 clinical trial. The milestone payment will be 
significantly reduced if a Phase 3 trial using the Company’s technology but not the IMGN529 antibody commences prior 
to IMGN529 entering a Phase 3 trial. The Company does not believe this scenario is likely to occur. 

Viridian  

In October 2020, the Company entered into a license agreement with Viridian Therapeutics, Inc. pursuant to 
which the Company granted Viridian the exclusive right to develop and commercialize an insulin-like growth factor-1 

67 

receptor (IGF-1R) antibody for all non-oncology indications that do not use radiopharmaceuticals in exchange for an 
upfront payment, with the potential to receive up to a total of $143.0 million in milestone payments plus royalties on the 
commercial sales of any resulting product. The total milestones are categorized as follows: development and regulatory 
milestones—$48.0 million; and sales milestones—$95.0 million. Viridian is responsible for the manufacturing, 
development, and marketing of any products resulting from the license agreement.  

Huadong 

In October 2020, the Company entered into a collaboration and license agreement with Hangzhou Zhongmei 

Huadong Pharmaceutical Co., Ltd. (Huadong), a subsidiary of Huadong Medicine Co., Ltd. The collaboration and 
license agreement grants Huadong an exclusive, royalty-bearing, and sublicensable right to develop and commercialize 
mirvetuximab (the Licensed Product) in the People’s Republic of China, Hong Kong, Macau, and Taiwan (collectively, 
Greater China). The Company retains exclusive rights to the Licensed Product outside of Greater China. Under the terms 
of the collaboration and license agreement, the Company received a non-refundable upfront payment of $40.0 million 
with the potential for approximately $265.0 million in milestone payments. The total milestones are categorized as 
follows: development and regulatory milestones—$80.0 million; and sales milestones—$185.0 million. In addition, the 
Company is entitled to receive tiered percentage royalties ranging from low double digits to high teens as a percentage of 
commercial sales of the Licensed Product, if approved, by Huadong in Greater China, subject to adjustment in specified 
circumstances.  

The Company evaluated the agreement and determined it was within the scope of ASC 606. The Company 

determined the promised goods and services included the license to intellectual property and know-how and the clinical 
supply of the Licensed Product to Huadong for a specified period. The Company concluded that the license to 
intellectual property and know-how is not distinct from the clinical supply of the Licensed Product because the clinical 
supply is essential to the use of the license and an alternative source of clinical supply is not readily available in the 
marketplace. Accordingly, these two promised goods and services are considered a single combined performance 
obligation. The Company determined there were no options in the agreement that represented material rights.  

The transaction price was determined to consist of the upfront payment of $40.0 million and estimated 
payments to be received for clinical supply of the Licensed Product. Future development and regulatory milestones have 
been fully constrained. Any consideration related to sales-based milestones (including royalties) will be recognized when 
the related sales occur as these amounts have been determined to relate predominantly to the license granted to Huadong. 
The Company re-evaluates the transaction price, including its estimated variable consideration included in the 
transaction price and all constrained amounts, at each reporting period and as uncertain events are resolved or other 
changes in circumstances occur. 

The Company determined that revenue related to the agreement would be recognized as the clinical supply of 
the Licensed Product is delivered to Huadong, estimated to be completed over approximately two years. The Company 
has estimated the total clinical supply to be delivered during this time and will reassess the percentage of clinical supply 
that has been delivered on an ongoing basis. If a change in estimate is determined to be necessary, the Company will 
adjust revenue using a cumulative catch-up method. No revenue related to this agreement has been recognized in the 
year ended December 31, 2020. 

Terminated Agreements 

Jazz Pharmaceuticals 

In August 2017, the Company entered into a Collaboration and Option Agreement (the “Option Agreement”) 

with Jazz Pharmaceuticals Ireland Limited (Jazz), a subsidiary of Jazz Pharmaceuticals plc, granting Jazz exclusive, 
worldwide rights to opt into development and commercialization of two early-stage, hematology-related ADC programs, 
as well as an additional program to be designated during the term of the agreement. The programs covered under the 
agreement included IMGN779, a CD33-targeted ADC for the treatment of acute myeloid leukemia (AML) then in Phase 
1 testing, IMGN632, a CD123-targeted ADC for hematological malignancies also then in Phase 1 testing, and an early-
stage program to be determined at a later date. As part of the Option agreement, Jazz made an upfront payment of $75 
million to the Company. Additionally, Jazz had also agreed to pay the Company up to $100 million in development 
funding over seven years to support the three ADC programs.  

In October 2019, Jazz exercised certain opt-out rights under the Option Agreement following the termination of 

the Company’s IMGN779 development program. In addition, in November 2019, the Company executed a First 
Amendment (the “First Amendment”) to the Option Agreement. The First Amendment included an exercise of Jazz’s 
opt-out rights related to the termination of the Company’s early research programs covered by the Option Agreement in 
connection with the Company’s previously announced restructuring. Under the terms of the Option Agreement, the 

68 

exercise of both of these opt-out rights resulted in a pro-rata reduction in Jazz’s obligation to provide development 
funding, with support being limited to the Company’s IMGN632 development program.  

In December 2020, the Company received notice that, based on the outcome of an internal portfolio review, 

Jazz exercised its opt out rights with respect to IMGN632, thereby relinquishing the development and commercialization 
option. As a result of Jazz’s opting out, the Company retains all rights to IMGN632 and is continuing global 
development of IMGN632 without further involvement by Jazz, except that Jazz will continue to provide a 
predetermined amount of research funding for the IMGN632 program over the next twelve months. Due to the timing of 
the Jazz opt out, the Company will not owe royalty payments to Jazz on commercial sales of IMGN632 if it is approved. 

Due to the involvement the Company and Jazz both had in the development and commercialization of the 
products, as well as both parties being part of the cost share agreement and exposed to significant risks and rewards 
dependent on the commercial success of the products, the arrangement was determined to be a collaborative arrangement 
within the scope of ASC 808. Accordingly, the Company carved out the research and development activities and the 
related cost sharing arrangement with Jazz. Payments for such activities are recorded as research and development 
expense and reimbursements received from Jazz are recognized as an offset to research and development expense in the 
accompanying statement of operations during the development period. Included in research and development expense 
for the years ended December 31, 2020, 2019 and 2018, are $6.7 million, $12.5 million, and $10.0 million of credits 
related to reimbursements from Jazz, respectively. 

The non-refundable, upfront arrangement consideration of $75 million was allocated to the three license 
options. The amount allocated to the rights to future technological improvements under the relative selling price method 
was deemed immaterial and, therefore, not segregated from the license options. In conjunction with the opt-out of 
IMGN779, the Company recognized $14.5 million of the deferred revenue in the year ended December 31, 2019. In 
connection with the execution of the First Amendment, the amount of the transaction price originally allocated to the 
early research product Options was reallocated to the to the IMGN632 Option, which represented the only remaining 
material right. The remaining $60.5 million of previously deferred license revenue was recognized upon the opt-out of 
the right to execute the last license by Jazz in December 2020. 

Takeda 

In March 2015, the Company entered into a three-year right-to-test agreement with Takeda Pharmaceutical 

Company Limited (Takeda) through its wholly-owned subsidiary, Millennium Pharmaceuticals, Inc., pursuant to which 
the Company received a $20 million upfront payment. A first license was granted to Takeda in 2015, whereupon the 
Company recognized $8.6 million of the arrangement consideration allocated to the development and commercialization 
licenses. In 2018, the right-to-test agreement expired without Takeda exercising its option to a second license. 
Accordingly, the remaining $10.9 million of revenue that had been deferred for such performance obligations was 
recognized as revenue and is included in license and milestone fees for the year ended December 31, 2018. In May 2018, 
Takeda enrolled its first patient in a Phase 1 clinical trial, triggering a $5.0 million milestone payment to the Company. 
Due to the likelihood of this milestone being attained, this milestone was recognized as a contract asset as part of the 
cumulative adjustment to transition to ASC 606. It had been previously allocated to the delivered license and the right to 
technological improvements. In 2020, Takeda terminated its exclusive development and commercialization license. As a 
result, the Company recorded the remaining $0.9 million balance of the upfront payment that had been allocated to 
future performance obligations under the license as revenue, which is included in license and milestone fees for the year 
ended December 31, 2020.   

Biotest 

In 2006, the Company granted Biotest an exclusive development and commercialization license to the 
Company’s maytansinoid ADC technology for use with antibodies that target CD138, pursuant to which the Company 
received a $1 million upfront payment. In 2020, Biotest terminated the license. 

Lilly 

Under a now-expired right-to-test agreement established in 2011, the Company granted Eli Lilly and Company 

(Lilly) three exclusive development and commercialization licenses, for which the Company received a $20 million 
upfront payment in connection with the execution of the right-to-test agreement and exercise fees totaling $4 million for 
the three licenses taken. In October 2018, Lilly terminated its three development and commercialization licenses. As a 
result, the Company recorded the remaining unrecognized $0.7 million balance of the upfront payment that had been 
allocated to future performance obligations under this license as revenue, which is included in license and milestone fees 
for the year ended December 31, 2018. 

69 

D. 

Property and Equipment 

Property and equipment consisted of the following at December 31, 2020 and 2019 (in thousands): 

Leasehold improvements  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     $ 
Machinery and equipment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Computer hardware and software  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Furniture and fixtures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Assets under construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    

Less accumulated depreciation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
Property and equipment, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     $ 

  $ 

2020 
 21,890     $ 
 2,861  
 5,636  
 3,039  
 97  
 33,523   $ 
 (27,763) 

 5,760   $ 

2019 
 20,776  
 9,384  
 5,692  
 3,607  
 —  
 39,459  
 (32,466)  
 6,993  

  December 31,    December 31,   

Included in the table above are amounts capitalized for equipment under capital leases at December 31, 2020 

and 2019 totaling $2.1 million, net of accumulated amortization of $1.3 million and $1.0 million, respectively. 
Depreciation expense was $2.1 million, $4.0 million , and $7.4 million for the years ended December 31, 2020, 2019 and 
2018, respectively. As a result of the restructuring at the end of the second quarter of 2019, the Company recorded an 
impairment charge of $2.5 million to write down excess equipment to fair value. During the fourth quarter of 2019, the 
Company executed an agreement to liquidate the equipment and transferred title to assets with a cost basis of $14.2 
million and accumulated depreciation of $12.9 million, for which the Company received a $2 million payment. During 
the year ended December 31, 2020, the Company liquidated the remaining equipment with a cost basis of $6.7 million 
for an additional $1.2 million payment to the Company. 

E. 

Convertible 4.5% Senior Notes 

In 2016, the Company issued convertible notes with an aggregate principal amount of $100 million, of which 

$2.1 million remains outstanding as of December 31, 2020. The convertible notes are governed by the terms of an 
indenture between the Company, as issuer, and Wilmington Trust, National Association, as the trustee. The convertible 
notes are senior unsecured obligations and bear interest at a rate of 4.5% per year, payable semi-annually in arrears on 
January 1 and July 1 of each year, commencing on January 1, 2017. The Company recorded $0.1 million of interest 
expense in each of the years ended December 31, 2020, 2019 and 2018, respectively. The convertible notes will mature 
on July 1, 2021, unless earlier repurchased or converted. Holders may convert their notes at their option at any time prior 
to the close of business on the business day immediately preceding the stated maturity date. Upon conversion, the 
Company will deliver for each $1,000 principal amount of converted notes a number of shares equal to the conversion 
rate, which will initially be 238.7775 shares of common stock, equivalent to an initial conversion price of approximately 
$4.19. The conversion rate will be subject to adjustment in some circumstances but will not be adjusted for any accrued 
and unpaid interest. The Company analyzed the terms of the convertible notes and determined that under current 
accounting guidance the notes would be entirely accounted for as debt and none of the terms of the notes require 
separate accounting. 

F. 

Liability Related to Sale of Future Royalties 

In 2015, IRH purchased the right to receive 100% of the royalty payments on commercial sales of Kadcyla 

arising under the Company’s development and commercialization license with Genentech, until IRH had received 
aggregate royalties equal to $235 million or $260 million, depending on when the aggregate royalties received by IRH 
reached a specified milestone. Once the applicable threshold was met, if ever, the Company would thereafter have 
received 85% and IRH would have received 15% of the Kadcyla royalties for the remaining royalty term. At 
consummation of the transaction the Company received cash proceeds of $200 million. As part of this sale, the Company 
incurred $5.9 million of transaction costs, which are presented net of the liability in the accompanying consolidated 
balance sheet and are being amortized to interest expense over the estimated life of the royalty purchase agreement. 
Although the Company sold its rights to receive royalties from the sales of Kadcyla, as a result of its ongoing 
involvement in the cash flows related to these royalties, the Company continues to account for these royalties as revenue 
and recorded the $200 million in proceeds from this transaction as a liability related to sale of future royalties (Royalty 
Obligation) that will be amortized using the interest method over the estimated life of the royalty purchase agreement. 

In January 2019, the Company sold its residual rights to receive royalty payments on commercial sales of 

Kadcyla to OMERS, the defined benefit pension plan for municipal employees in the Province of Ontario, Canada, for a 
net payment of $65.2 million (amount is net of $1.5 million in broker fees). Simultaneously, OMERS purchased IRH’s  

70 

 
 
 
 
 
 
 
 
 
 
     
 
 
  
  
  
  
  
  
  
  
 
  
  
right to the royalties the Company previously sold as described above, therefore obtaining the rights to 100% of the 
royalties received from that date on. Because the Company will not be involved with the cash flows related to the 
residual royalties, the $65.2 million of net proceeds received from the sale of its residual rights to receive royalty 
payments was recorded as deferred revenue and will be amortized as the royalty revenue related to the residual rights is 
earned using the units of revenue approach. Through December 31, 2020, no revenue related to the residuals rights was 
recognized. Additionally, the purchase of IRH’s interest by OMERS did not result in an extinguishment or modification 
of the original instrument and, accordingly, the Company will continue to account for the remaining obligation as a 
liability as outlined above.   

The following table shows the activity within the liability account during the year ended December 31, 2020 

and the period from inception (in thousands): 

Year Ended  

Period from 
inception to 

     December 31, 2020       December 31, 2020 

Liability related to sale of future royalties, net — beginning balance . . . . . . .    $ 
Proceeds from sale of future royalties, net . . . . . . . . . . . . . . . . . . . . . . . . . .  
Kadcyla royalty payments received and paid . . . . . . . . . . . . . . . . . . . . . . . .  
Non-cash interest expense recognized  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Liability related to sale of future royalties, net — ending balance  . . . . . . . . .    $ 

 123,541  $ 
 — 
 (61,195) 
 23,093 
 85,439  $ 

 — 
 194,135 
 (206,367)
 97,671 
 85,439 

As royalties are remitted to IRH and subsequently OMERS, the balance of the Royalty Obligation will be 

effectively repaid over the life of the agreement. In order to determine the amortization of the Royalty Obligation, the 
Company is required to estimate the total amount of future royalty payments to be received and remitted as noted above 
over the life of the agreement. The sum of these amounts less the $200 million proceeds the Company received will be 
recorded as interest expense over the life of the Royalty Obligation. Since inception, the Company’s estimate of this total 
interest expense results in an imputed annual interest rate of 10.5% and a current imputed interest rate of 22.2% as of 
December 31, 2020. The Company periodically assesses the estimated royalty payments to IRH/OMERS and to the 
extent such payments are greater or less than its initial estimates, or the timing of such payments is materially different 
than its original estimates, the Company will prospectively adjust the amortization of the Royalty Obligation. There are a 
number of factors that could materially affect the amount and timing of royalty payments from Genentech, most of 
which are not within the Company’s control. Such factors include, but are not limited to, changing standards of care, the 
introduction of competing products, manufacturing or other delays, biosimilar competition, patent protection, adverse 
events that result in governmental health authority imposed restrictions on the use of the drug products, significant 
changes in foreign exchange rates as the royalties remitted to IRH/OMERS are made in U.S. dollars (USD) while 
significant portions of the underlying sales of Kadcyla are made in currencies other than USD, and other events or 
circumstances that could result in reduced royalty payments from Kadcyla, all of which would result in a reduction of 
non-cash royalty revenues and the non-cash interest expense over the life of the Royalty Obligation. Conversely, if sales 
of Kadcyla are more than expected, the non-cash royalty revenues and the non-cash interest expense recorded by the 
Company would be greater over the term of the Royalty Obligation. 

In addition, the royalty purchase agreement grants IRH/OMERS the right to receive certain reports and other 
information relating to the royalties and contains other representations and warranties, covenants, and indemnification 
obligations that are customary for a transaction of this nature. 

71 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  
  
  
 
 
G. 

Income Taxes 

The difference between the Company’s expected tax benefit, as computed by applying the applicable U.S. 

federal corporate tax rate to loss before the benefit for income taxes, and actual tax is reconciled in the following chart 
(in thousands): 

Years Ended December 31, 

Loss before income tax expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        $ 
Expected tax benefit at 21% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      $ 
Permanent differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Incentive stock options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
State tax benefit net of federal benefit . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Change in valuation allowance, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Federal research credit  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Federal orphan drug credit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Expired loss and credit carryforwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Lease incentive  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Stock option expirations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Benefit for income taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   

$ 

2018 

2020 
2019 
 (44,372)    $   (104,133)    $  (168,843)
 (21,868)  $   (35,457)
 (9,318)  $ 
 (103)
 157   
 1,144 
 201   
 (10,622)
 (2,250) 
 53,706 
 15,175   
 (2,466)
 (228) 
 (6,934)
 (6,218) 
 — 
 419   
 —   
 109 
 623 
 2,062   
 — 

 320  
 569  
 (6,726) 
 27,812  
 (1,652) 
 (4,426) 
 500  
 —  
 5,471  

 —    $ 

 —   $ 

At December 31, 2020, the Company has net operating loss, or NOL, carryforwards of $471.6 million available 

to reduce federal taxable income, if any, that begin to expire in 2028 through 2037 and $373.7 million of the federal 
NOL carryforwards can be carried forward indefinitely. The Company has $677.1 million of NOL carryforwards 
available to reduce state taxable income, if any, that expire in 2033 through 2040. The Company also has federal and 
state credit carryforwards of $70.4 million and $13.0 million, respectively, available to offset federal and state income 
taxes, which expire beginning in 2022. 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 purposes. Significant 
components of the Company’s deferred tax assets and liabilities as of December 31, 2020 and 2019 are as follows (in 
thousands): 

December 31,  

2020 

2019 

Deferred tax assets: 

Net operating loss carryforwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $   220,286   $   191,744 
Research and development tax credit carryforwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
 75,084 
Property and other intangible assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
 809 
 36,008 
Deferred revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
 9,630 
 6,767 
Operating lease liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
 2,255 
Other liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Royalty sale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
 30,030 
Total deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $   366,875   $   352,327 

 80,694  
 871  
 30,082  
 9,940  
 6,033  
 1,514  
 17,455  

Deferred tax liabilities: 

Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Operating lease right of use asset  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Royalty sale transaction costs  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Total deferred tax liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 
Valuation allowance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Net deferred tax assets/(liabilities) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 

 (58) 
 (3,844) 
 (247) 
 (4,149)  $ 

 (110)
 (4,258)
 (408)
 (4,776)
    (347,551)
 — 

   (362,726) 

 —   $ 

The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax 

assets. The Company has determined that it is not more-likely-than-not that the tax benefits related to the federal and 
state deferred tax assets will be realized for financial reporting purposes. Accordingly, the deferred tax assets have been 
fully reserved at December 31, 2020 and 2019. The valuation allowance increased by $15.2 million during the year 
ended December 31, 2020 due primarily to additional net loss incurred during the year. 

72 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
     
 
  
  
  
 
 
 
  
  
  
  
  
  
  
  
  
 
 
 
 
 
 
 
 
 
  
  
  
 
 
 
 
 
 
 
 
 
 
     
 
 
 
 
     
 
 
  
 
  
 
  
 
  
 
  
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Utilization of the NOL and 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 Sections 382 
and 383 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 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. During fiscal year 2015, the Company completed a study to 
assess whether a change of control has occurred or whether there have been multiple changes of control since its 
formation and determined no ownership change occurred under Section 382. This study was updated through 
December 31, 2020 resulting in the same conclusion. Additionally, the Company has not completed a detailed Research 
and Development Credit Study (including the Orphan Drug Credit); accordingly, a portion of the tax credit carryforward 
may not be available to offset future income.  

The Company accounts for uncertain tax positions under the recognition and measurement criteria of ASC 
740-10. For those tax positions for which it is more likely than not that a tax benefit will be sustained, the Company 
records the largest amount of tax benefit with a greater than 50% likelihood of being realized upon settlement with a 
taxing authority that has full knowledge of all relevant information. If the Company does not believe that it is not more 
likely than not that a tax benefit will be sustained, no tax benefit is recognized. As of December 31, 2020 and 2019, no 
uncertain tax positions have been recorded. 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 
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 its effective tax rate.  

The statute of limitations for assessment by the Internal Revenue Service, or IRS, and state tax authorities is 

open for tax years ending after December 31, 2017, although carryforward attributes that were generated prior to 
2017 may still be adjusted upon examination by the IRS or state tax authorities if they either have been or will be used in 
a future period.  

H. 

Capital Stock 

Common Stock Reserved 

At December 31, 2020, the Company has reserved 25.0 million shares of authorized common stock for the 

future issuance of shares under the 2018, ESPP and Inducement Plans. See “Stock-Based Compensation” in Note B for a 
description of the 2018, ESPP, and Inducement Plans. 

Stock Options 

As of December 31, 2020, the 2018 Plan and the Inducement Plan were the only employee share-based 

compensation plans of the Company under which grants can be made. During the year ended December 31, 2020, 
holders of options issued under the option plans exercised their rights to acquire an aggregate of 336,000 shares of 
common stock at prices ranging from $2.31 to $5.25 per share. The total proceeds to the Company from these option 
exercises were $1.0 million. 

73 

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 December 31, 2020, 2019, and 2018: 

December 31, 2020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
December 31, 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    
December 31, 2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    

2004 Non-Employee Director Compensation and Deferred Share Unit Plan 

Exercisable 
(in thousands)   
6,983  
 5,801 
 8,405 

  $ 
  $ 
  $ 

     Weighted(cid:4137) 
Average 
Exercise Price 

8.15   
10.16   
11.47   

Under the 2004 Non-Employee Director Compensation and Deferred Share Unit Plan, or the 2004 Director 

Plan, as amended, between 2004 and 2009 non-employee directors were paid their annual retainers in the form of 
deferred stock units, based on the fair market value of the Company’s common stock on the last date of the Company’s 
fiscal year prior to the year for which services were rendered, and in cash, with the option, at their discretion, to have all 
or a portion of the cash portion paid in additional deferred stock units. All deferred stock units awarded under the 2004 
Director Plan have vested and 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 common stock of the Company issued under the 2006 
Plan at a rate of one share for each vested unit. 

Compensation Policy for Non-Employee Directors 

In September 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 
Compensation Policy for Non-Employee Directors, as amended as of June 2020, consists of three elements: cash 
compensation; deferred stock units; and stock options. 

Cash Compensation 

Each non-employee director receives annual meeting fees which are paid in quarterly installments in, at each 

director’s election, either cash or deferred stock units. 

Deferred Stock Units 

Pursuant to the Compensation Policy for Non-Employee Directors, as amended, non-employee directors receive 

deferred stock units upon initial election to the Board and annually thereafter. 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 
generally be settled in shares of the Company’s common stock issued under our 2018 Plan (or its predecessor plans, 
depending on the grant date of the deferred stock units) 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. Pursuant to the Compensation Policy 
for Non-Employee Directors, in 2018, the Company issued retiring directors 172,509 shares of common stock of the 
Company to settle outstanding deferred share units. 

Pursuant to the Compensation Policy for Non-Employee Directors, as amended, the Company recorded: 

• 

• 

• 

$0.3 million in compensation expense during the year ended December 31, 2020 related to the grant of 
127,000 deferred share units and 15,000 deferred share units previously granted; 

$0.3 million in compensation expense during the year ended December 31, 2019 related to the grant of 
63,000 deferred share units and 18,000 deferred share units previously granted; and 

$0.4 million in compensation expense during the year ended December 31, 2018 related to the grant of 
46,000 deferred share units and 10,500 deferred share units previously granted. 

Stock Options 

Pursuant to the Compensation Policy for Non-Employee Directors, as amended, non-employee directors also 
receive stock option awards upon initial election to the Board and annually thereafter. The directors received a total of 
300,000, 108,000, and 128,000 options in the years ended December 31, 2020, 2019, and 2018, and the related stock 

74 

 
 
 
 
 
 
 
 
    
 
  
 
 
 
  
 
 
  
 
compensation expense is included in the amounts discussed in the “Stock-Based Compensation” section of footnote B 
above.  

I. 

Restructuring Charge 

2019 Corporate Restructuring 

On June 26, 2019, the Board of Directors approved a plan to restructure the business to focus resources on 

continued development of mirvetuximab and a select portfolio of three earlier-stage product candidates, resulting in a 
significant reduction of our workforce, with a majority of these employees separating from the business by mid-
July 2019 and most of the remaining affected employees transitioning over varying periods of time of up to 12 months. 
Communication of the plan to the affected employees was substantially completed on June 27, 2019. 

 As a result of the workforce reduction, during the three months ended June 30, 2019, the Company recorded a 

$16.0 million charge for severance related to a pre-existing plan in accordance with ASC 712, Compensation-
Nonretirement Postemployment Benefits, as such amounts were probable and reasonably estimable. The estimate was 
reduced during the year to $15.3 million due to minor adjustments to the plan. The related cash payments were 
substantially paid out by June 30, 2020. In addition, a charge of $4.0 million was incurred for incremental retention 
benefits over the same time period, of which $1.6 million and $2.4 million was recorded during the years ended 
December 31, 2020 and 2019, respectively. 

A summary of activity against the corporate restructuring charge related to the employee terminations in 2019 

is as follows: 

Employee  
Termination 
Benefits Costs 

Balance at December 31, 2019 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 
Additional charges/adjustments during the period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Payments during the period  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Balance at December 31, 2020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $ 

 4,087 
 (116)
 (3,187)
 784 

In addition to the termination benefits and other related charges, the Company has sub-leased laboratory and 

office space at 830 Winter Street in Waltham, Massachusetts no longer used in the business. The decision to vacate part 
of its corporate office resulted in a change in asset groupings and also represented an impairment indicator. The 
Company determined and continues to believe that the right-of-use asset and leasehold improvements are recoverable 
based on expected sublease income, and therefore, no impairment has been recorded.  

In addition, the Company also decided to liquidate excess laboratory equipment and expected the proceeds to be 

less than the carrying value. As a result, in 2019, the Company recorded an impairment charge of $2.5 million to write 
down the equipment to fair value based on current market re-sale estimates obtained.  

2018 Manufacturing Restructuring 

In February 2018, following an in-depth review of manufacturing and quality operations, the Board of Directors 
authorized management to implement a new operating model that will rely on external manufacturing and quality testing 
for drug substance and drug product for the Company’s development programs. The implementation of this new 
operating model led to the ramp-down of manufacturing and quality activities at the Norwood, Massachusetts facility by 
the end of 2018, and a full decommissioning of the facility in February 2019. Implementation of the new operating 
model resulted in the separation of 22 employees. Communication of the plan to the affected employees was 
substantially completed on February 8, 2018. 

In connection with the implementation of the new operating model, the Company recorded a one-time charge of 

$1.2 million for severance related to a pre-existing plan in the first quarter of 2018 in accordance with ASC 712, 
Compensation-Nonretirement Postemployment Benefits, as such amounts were probable and reasonably estimable. 
Additional expense was recorded for incremental retention benefits over the remaining service period of the related 
employees, as well as marginal adjustments to severance resulting from voluntary terminations, which totaled $2.3 
million for the remainder of 2018. Cash payments related to retention benefits were paid in the fourth quarter of 2018 
and those related to severance were paid out by the end of the third quarter of 2019. Additionally, certain options held by 
the employees to be separated were modified to extend the exercise period, resulting in a stock compensation charge of 
$0.2 million in the first quarter of 2018.  

75 

 
 
 
 
 
 
 
 
 
    
 
 
Charge Related to Unoccupied Office Space 

The Company has sought to sub-lease 10,281 square feet of unoccupied office space at 930 Winter Street in 

Waltham, Massachusetts that was leased in 2016. During 2019, the Company recorded a $0.6 million impairment charge 
related to this lease, which represented the remaining balance of the right to use asset as the likelihood of finding a sub-
lessor had diminished significantly as the lease approaches termination. 

J. 

Leases 

Leases 

The Company currently has two real estate leases. The first is an agreement with CRP/King 830 Winter L.L.C. 

for the rental of approximately 120,000 square feet of laboratory and office space at 830 Winter Street, Waltham, 
Massachusetts through March 2026. The Company uses this space for its corporate headquarters and other operations. 
The Company may extend the lease for two additional terms of five years and is required to pay certain operating 
expenses for the leased premises subject to escalation charges for certain expense increases over a base amount. During 
2020, the Company executed four subleases for approximately 65,000 square feet through the remaining initial term of 
the lease. The balance of the space will be used by the Company. The second real estate lease is an agreement with PDM 
930 Unit, LLC for the rental of 10,281 square feet of additional office space at 930 Winter Street, Waltham, 
Massachusetts through August 31, 2021. The Company is required to pay certain operating expenses for the leased 
premises based on its pro-rata share of such expenses for the entire rentable space of the building. The Company ended 
its lease and vacated its manufacturing and office space at 333 Providence Highway, Norwood, Massachusetts in 
February 2019 pursuant to the restructuring plan described previously. 

In addition to the two real estate leases noted above, the Company currently has a lease agreement through 

November 2023 for the rental of copier equipment. 

During the first quarter of 2019, the Company adopted ASC 842 by recognizing and measuring leases existing 

at, or entered into after, January 1, 2019. In accordance with the transition method provided by ASC 2018-11, the 
Company adopted and initially applied the new leasing rules on January 1, 2019, rather than at the earliest comparative 
period presented in the financial statements. Therefore, prior periods presented are in accordance with the previous lease 
guidance (ASC 840). As permitted by the new lease standard, the Company elected to apply the following practical 
expedients to the entire lease portfolio: (i) not to reassess whether any expired or existing contracts are or contain leases 
or the classification of any expired or existing leases; (ii) not to apply the recognition requirements to short-term leases; 
and (iii) not to separate fixed nonlease components from associated lease components for the underlying assets. 

Upon adoption, a ROU asset of $17.6 million and a lease liability of $27.3 million were recorded and are 
identified separately in the Company’s consolidated balance sheets for the existing operating leases. There was no 
impact to the consolidated statements of operations. Upon adoption, the amount of the ROU assets recorded was offset 
by the applicable unamortized lease incentive and straight-line lease liability balances of $9.7 million and, therefore, 
there was no impact to accumulated deficit. There were no initial direct costs related to the leases to consider. The 
Company’s operating lease liabilities related to its real estate lease agreements were calculated using a collateralized 
incremental borrowing rate. The weighted average discount rate for the operating lease liability is approximately 11%. A 
100-basis point change in the incremental borrowing rate would result in less than a $1 million impact to the ROU assets 
and liabilities recorded. Lease expense for operating lease payments is recognized on a straight-line basis over the lease 
term, which for the years ended December 31, 2020, 2019, and 2018 was $4.0 million, $4.3 million, and $5.8 million, 
respectively, and is included in operating expenses in the consolidated income statements. During 2019, the Company 
recorded $0.6 million of impairment charges related to its 930 Winter Street lease, which represents the remaining 
balance of the right to use asset as the likelihood of finding a sub-lessor has diminished significantly as the lease 
approaches termination. Cash paid against operating lease liabilities during the years ended December 31, 2020 and 
2019 was $5.5 million and $5.3 million, respectively. As of December 31, 2020, the Company’s ROU assets and lease 
liabilities for operating leases totaled $14.1 million and $21.8 million, respectively, and the weighted average remaining 
term of the operating leases is approximately five years. 

76 

The maturities of operating lease liabilities discussed above are as follows (in thousands): 

2021 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       $ 
2022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
2023 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
2024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
2025 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Thereafter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
     Total lease payments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
Less imputed interest  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   
     Total lease liabilities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   

$ 

 5,323 
 5,389 
 5,510 
 5,470 
 5,490 
 1,376 
 28,558 
 (6,761)
 21,797 

In addition to the amounts in the table above, the Company is also responsible for variable operating costs and 

real estate taxes approximating $3.1 million per year through March 2026. 

Sublease Income 

In 2020, the Company executed four agreements to sublease a total of approximately 65,000 square feet of the 

Company’s leased space at 830 Winter Street, Waltham, Massachusetts through March 2026. During the year ended 
December 31, 2020, the Company recorded $2.8 million of sublease income, inclusive of the sublessees’ proportionate 
share of operating expenses and real estate taxes for the period. 

Two of the four sublease agreements include an early termination option after certain periods of time for an 

agreed-upon fee. Assuming no early termination option is exercised, the Company will receive $15.9 million in 
minimum rental payments over the remaining term of the subleases, which is not included in the operating lease liability 
table above. The sublessees are also responsible for their proportionate share of variable operating expenses and real 
estate taxes. 

K. 

Commitments and Contingencies 

Manufacturing Commitments 

As of December 31, 2020, the Company has noncancelable obligations under several agreements related to in-

process and future manufacturing of antibody and cytotoxic agents required for supply of the Company’s product 
candidates totaling $6.5 million, which will be paid in 2021. Additionally, pursuant to commercial agreements for future 
production of antibody, our noncancelable commitments total approximately $36.0 million at December 31, 2020. 

Litigation 

The Company is not party to any material litigation. 

L. 

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 the years ended December 31, 2020, 2019 and 2018, the Company’s contributions to the 401(k) Plan 
totaled $0.4 million, $0.8 million, and $1.0 million, respectively. 

77 

 
 
 
 
  
  
  
  
  
 
 
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, or the Exchange Act) 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: 

• 

• 

• 

pertain to the maintenance of records that in reasonable detail accurately and fairly reflect our transactions 
and dispositions of our assets; 

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 

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 December 31, 

2020. 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 2013. 

Based on this assessment, management has concluded that, as of December 31, 2020 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 December 31, 2020. This report appears immediately below. 

78 

 
 
(b) 

Attestation Report of the Independent Registered Public Accounting Firm 

Report of Independent Registered Public Accounting Firm 

To the Shareholders and the Board of Directors of ImmunoGen, Inc.  

Opinion on Internal Control over Financial Reporting 

We have audited ImmunoGen, Inc.’s internal control over financial reporting as of December 31, 2020, based on criteria 
established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the 
Treadway Commission (2013 framework), (the COSO criteria). In our opinion, ImmunoGen, Inc. (the Company) 
maintained, in all material respects, effective internal control over financial reporting as of December 31, 2020, based on 
the COSO criteria.  

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United 
States) (PCAOB), the consolidated balance sheets of the Company as of December 31, 2020 and 2019, the related 
consolidated statements of operations and comprehensive loss, shareholders’ equity (deficit) and cash flows for each of 
the three years in the period ended December 31, 2020 and the related notes and our report dated March 1, 2021 
expressed an unqualified opinion thereon. 

Basis for Opinion 

The Company’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 are a public accounting firm registered with 
the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal 
securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. 

We conducted our audit in accordance with the standards of the PCAOB. 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. 

Definition and Limitations of Internal Control Over Financial Reporting 

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. 

/s/ Ernst & Young LLP  

Boston, Massachusetts  

March 1, 2021 

79 

 
 
(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 December 31, 2020 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 

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 2021 annual meeting of shareholders, which will be filed with the Securities and 
Exchange Commission not later than April 30, 2021 (120 days after the end of the year covered by this report), except 
that information required by Item 10 concerning our executive officers appears in Part I, Item 3.1 of this report. 

Item 15.  Exhibits, Financial Statement Schedules 

PART IV 

(a) 

Documents filed as part of this Report: 
(1) 
Schedules.  
(2) 

Financial Statement Schedules: 

See the financial statements of ImmunoGen, Inc. at Item 8 of this report. Financial Statement 

information appears in the accompanying Consolidated Financial Statements or Notes thereto. 

Schedules not included herein are omitted because they are not applicable, or the required 

(3) 

Exhibit Index 

80 

 
 
 
 
Exhibit 
Number 
 3.1 
 3.1(a) 
 3.1(b) 
 3.1(c) 
 3.2 
 4.1 

 4.1(a) 

 4.2 

 4.2(a) 

4.3 
10.1 

10.1(a) 

10.1(b) 

10.1(c) 

10.1(d) 

10.2* 

10.3* 

10.3(a)* 

10.4* 

10.5* 

10.6** 

10.7* 

Filed 
with this 
Form 10-K    

Exhibit Description 

  Restated Articles of Organization, as amended 
  Articles of Amendment 
  Articles of Amendment 
  Articles of Amendment 
  Amended and Restated By-Laws 

Article 4 of Restated Articles of Organization, as 
amended (see Exhibit 3.1) 
Indenture, dated as of June 20, 2016, by and 
between the Registrant and Wilmington Trust, 
National Association, as Trustee 
Form of Common Stock certificate 

Form of Note representing the Registrant’s 4.50% 
Convertible Senior Notes due 2021 (included as 
Exhibit A to the Indenture filed as Exhibit 4.1(a)) 

  Description of Securities 

X 

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 
Third Amendment to Lease Agreement dated as of 
December 14, 2015 by and between CRP/King 830 
Winter, L.L.C., landlord, and the Registrant 
Fourth Amendment to Lease Agreement dated as of 
April 6, 2018 by and between CRP/King 830 
Winter, L.L.C., landlord, and the Registrant 
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 Società Italiana Corticosteroidi S.r.l. (Sicor) 
Exclusive License and Asset Purchase Agreement 
dated as of May 23, 2017 by and between the 
Registrant and Debiopharm International, S.A. 
Collaboration and License Agreement 
effective as of October 19, 2020 by and 
between the registrant and Hangzhou 
Zhongmei Huadong Pharmaceutical Co., Ltd., 
a subsidiary of Huadong Medicine Co., Ltd.  
Royalty Purchase Agreement dated as of January 8, 
2019 among the Registrant, Hurricane, LLC, 
Immunity Royalty Holdings, L.P., and OMERS IP 
Healthcare Holdings Limited 

X 

81 

Incorporated by Reference 
Filing Date 
with SEC 

August 5, 2020  
January 30, 2013 
August 4, 2017 
August 5, 2020 
June 20, 2016 

Exhibit 
Number 
3.1 
3.1 
3.1 
3.1(c) 
3.1 

Form 
10-Q 
10-Q 
10-Q 
10-Q 
8-K 

8-K 

S-1 

June 20, 2016

4.1 

November 15, 1989
(File No. 33-31219) 

4.2 

10-Q 

November 7, 2007

10.2 

10-Q 

February 5, 2014

10.1 

10-Q 

May 2, 2014

10.1 

10-Q 

10-Q 

10-Q 

February 4, 2016 

10.1

May 9, 2018

10.2

May 9, 2018

10.3 

10-Q/A 

August 19, 2015

10.2 

10-Q 

May 6, 2013

10.1 

10-Q 

10-Q 

February 8, 2011

10.1 

August 4, 2017

10.1

10-K 

March 1, 2019

10.13 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
   
   
   
   
 
 
   
 
 
   
 
 
   
 
 
   
 
 
 
   
 
 
   
 
 
   
 
 
 
 
   
 
 
 
   
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Exhibit 
Number 
10.8† 

10.8(a)† 

10.8(b)† 

10.8(c)† 

10.8(d)† 
10.8(e)† 

10.8(f)† 

10.8(g)† 

10.8(h)† 

10.8(i)† 

10.8(j)† 

10.9† 

10.9(a)† 
10.9(b)† 

10.9(c)† 

10.9(d)† 

10.9(e)† 
10.9(f)† 

10.10† 

Filed 
with this 
Form 10-K    

Exhibit Description 

2006 Employee, Director and Consultant Equity 
Incentive Plan, as amended and restated through 
November 11, 2014 
Form of Incentive Stock Option Agreement for 
Executives 
Form of Non-Qualified Stock Option Agreement 
for Executives 
Form of Non-Qualified Stock Option Agreement 
for Directors 
  Form of Director Deferred Stock Unit Agreement 
Form of Incentive Stock Option Agreement for all 
employees (including executives) 
Form of Non-Qualified Stock Option Agreement 
for all employees (including executives) 
Form of Non-Qualified Stock Option Agreement 
for Directors 
Form of Restricted Stock Agreement for all 
employees (including executives) 
Form of Incentive Stock Option for all employees 
(including executives) 
Form of Non-Qualified Stock Option Agreement 
for all employees (including executives) 
2016 Employee, Director and Consultant Equity 
Incentive Plan, as amended and restated through 
June 13, 2017 

  Form of Incentive Stock Option Agreement 

Form of Non-Qualified Stock Option Agreement 
for employees 
Form of Non-Qualified Stock Option Agreement 
for Non-Employee Directors 
Form of Deferred Stock Unit Agreement for Non-
Employee Directors 

  Form of Restricted Stock Agreement for employees    

Form of Performance-Based Restricted Stock 
Agreement dated February 21, 2017 and June 14, 
2017 
2018 Employee, Director and Consultant Equity 
Incentive Plan 

10.10(a)†    Form of Incentive Stock Option Agreement 
10.10(b)† 

Form of Non-Qualified Stock Option Agreement 
for employees 

10.10(c)†    Form of Restricted Stock Unit Agreement 
10.10(d)† 

10.10(e)† 

10.10(f)† 

10.11† 

10.12† 

10.13† 

10.14† 

Form of Non-Qualified Stock Option Agreement 
for Non-Employee Directors 
Form of Deferred Stock Unit Agreement for Non-
Employee Directors 
Form of Performance-Based Stock Option 
Agreement dated February 7, 2020 
Employee Stock Purchase Plan, as amended 
through September 27, 2019  
2004 Non-Employee Director Compensation and 
Deferred Stock Unit Plan, as amended on 
September 16, 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 March 31, 2017 between the Registrant and 
Anna Berkenblit 

Incorporated by Reference 
Filing Date 
with SEC 

Form 
8-K 

November 13, 2014

Exhibit 
Number 
10.1 

S-8 

S-8 

S-8 

10-Q 
10-K 

10-K 

10-K 

S-8 

8-K 

8-K 

8-K 

8-K 
8-K 

8-K 

8-K 

10-Q 
10-Q 

8-K 

8-K 
8-K 

8-K 
8-K 

8-K 

10-K 

10-Q 

10-Q 

10-Q 

10-Q 

November 15, 2006

99.4 

November 15, 2006

99.5 

November 15, 2006

99.6 

October 29, 2010 
August 29, 2012

10.1 
10.14(g)

August 29, 2012

10.14(h)

August 29, 2012

10.14(i)

November 21, 2012

99.1 

April 26, 2016

10.1

April 26, 2016

10.2

June 16, 2017

10.1

December 13, 2016 
December 13, 2016

10.2
10.3

December 13, 2016

10.4

December 13, 2016

10.5

August 4, 2017 
August 4, 2017

10.3
10.4

June 22, 2018

10.1 

June 22, 2018 
June 22, 2018

June 22, 2018 
June 22, 2018

10.2
10.3

10.4
10.5

June 22, 2018

10.6

March 11, 2020

10.11(f)

November 5, 2019

10.1

November 4, 2009

10.1 

February 8, 2007

10.15 

May 5, 2017

10.3 

82 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
   
   
   
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
   
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
   
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
 
 
   
 
 
 
 
   
 
 
 
   
 
 
 
   
 
 
 
   
 
 
 
   
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
Exhibit 
Number 
10.15† 

10.16† 

10.17† 

10.18† 

10.19† 

10.20† 

10.21† 

Exhibit Description 
Change in Control Severance Agreement dated as 
of March 31, 2017 between the Registrant and 
Mark J. Enyedy 
Change in Control Severance Agreement dated as 
of March 31, 2017 between the Registrant and 
Thomas Ryll 
Change in Control Severance Agreement dated as 
of March 31, 2017 between the Registrant and 
Theresa G. Wingrove 
Change in Control Severance Agreement dated as 
of July 20, 2020 between the Registrant and Susan 
Altschuller, Ph.D. 
Change in Control Severance Agreement dated as 
of June 1, 2020 between the Registrant and Stacy 
Coen 
Compensation Policy for Non-Employee Directors, 
as amended through June 17, 2020 
Severance Pay Plan for Vice Presidents and Higher, 
as amended through June 20, 2019 

  Summary of ImmunoGen Incentive Bonus Plan 
  Inducement Equity Incentive Plan, as amended 

10.22† 
10.23† 
10.23(a)†    Form of Non-Qualified Stock Option Agreement 
10.23(b)†    Form of Restricted Stock Unit Agreement 
Form of Performance-Based Stock Option 
Agreement (February 2020) under the Inducement 
Equity Incentive Plan 
Open Market Sale AgreementSM, dated 
December 18, 2020, by and between the Registrant 
and Jeffries LLC 
  Subsidiaries of the Registrant 
  Consent of Ernst & Young LLP 

10.24 

    10.23(c)† 

21 
23 
31.1 

32 

101 

104 

Certifications of the principal executive officer and 
principal financial officer pursuant to Section 302 
of the Sarbanes-Oxley Act of 2002  
Certifications of principal executive officer and 
principal financial officer pursuant to Section 906 
of the Sarbanes-Oxley Act of 2002 
Financial statements from the annual report on 
Form 10-K of ImmunoGen, Inc. for the year ended 
December 31, 2020 formatted in inline XBRL 
(eXtensible Business Reporting Language): (i) the 
Consolidated Balance Sheets; (ii) the Consolidated 
Statements of Operations and Comprehensive Loss; 
(iii) the Consolidated Statements of Shareholder’s 
(Deficit) Equity; (iv) the Consolidated Statements 
of Cash Flows; and (v) the Notes to Consolidated 
Financial Statements 
Cover Page Interactive Data File (formatted as 
Inline XBRL and contained in Exhibit 101) 

Incorporated by Reference 
Filing Date 
with SEC 

Exhibit 
Number 
10.4 

May 5, 2017

Form 
10-Q 

10-Q 

10-Q 

10-Q 

8-K 

10-Q 

8-K 
8-K 
8-K 
8-K 
10-Q 

May 5, 2017

10.7 

May 5, 2015

10.9 

August 5, 2020

10.4

June 18, 2020

10.1

August 7, 2019

10.1

February 20, 2018 
July 2, 2020 
December 20, 2019 
December 20, 2019 
August 5, 2020

10.1
10.1
10.2
10.3
10.2

8-K 

December 18, 2020

10.1

Filed 
with this 
Form 10-K    

X 

X 
X 
X 

X 

X 

X 

*  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. 

**  Certain confidential portions of this Exhibit were omitted by means of marking such portions with brackets [***] 
because the identified confidential portions (i) are not material and (ii) would be competitively harmful if publicly 
disclosed.  

†  Exhibit is a management contract or compensatory plan, contract or arrangement required to be filed as an exhibit to 

this report on Form 10-K. 

83 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
   
   
   
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
 
   
 
 
   
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
 
 
   
   
   
 
 
   
   
   
 
 
   
   
   
 
 
   
   
   
 
 
   
   
   
 
Item 16. Form 10-K Summary 

None 

84 

 
 
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/Mark J. Enyedy 
Mark J. Enyedy 
President and 
Chief Executive Officer 
(Principal Executive Officer) 

Dated:   March 1, 2021 

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/ MARK J. ENYEDY 
Mark J. Enyedy 

President, Chief Executive Officer and Director 
(Principal Executive Officer) 

/s/ Susan ALTSCHULLER Ph.D. 
Susan Altschuller Ph.D. 

Senior Vice President and Chief Financial Officer 
(Principal Financial Officer) 

/s/ Renee LENTINI 
Renee Lentini 

/s/ STEPHEN C. MCCLUSKI 
Stephen C. McCluski 

/s/ STUART A. ARBUCKLE 
Stuart A. Arbuckle 

/s/ MARK GOLDBERG, M.D. 
Mark Goldberg, M.D. 

/s/ DEAN J. MITCHELL 
Dean J. Mitchell 

/s/ KRISTINE PETERSON 
Kristine Peterson 

/s/ RICHARD J. WALLACE 
Richard J. Wallace 

March 1, 2021 

March 1, 2021 

March 1, 2021 

Vice President – Finance 
(Principal Accounting Officer) 

Chairman of the Board of Directors 

March 1, 2021 

March 1, 2021 

March 1, 2021 

March 1, 2021 

March 1, 2021 

March 1, 2021 

Director 

Director 

Director 

Director 

Director 

85 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
     
     
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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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, 2015 through December 31, 2020 (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. 

      Dec 2016        Dec 2017        Dec 2018        Dec 2019        Dec 2020 
44.85 
IMMUNOGEN, INC.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    $  100.00    $  21.42    $ 
NASDAQ STOCK MARKET INDEX (U.S.) . . . . . . . . . . . .    $  100.00    $  99.88    $  111.78    $  144.53    $  142.17    $  193.50    $  278.52 
NASDAQ PHARMACEUTICAL STOCKS TOTAL 

35.50    $ 

14.19    $ 

33.38    $ 

44.58    $ 

      2015 

      2016 

RETURN INDEX (U.S.) . . . . . . . . . . . . . . . . . . . . . . . . .    $  100.00    $  71.95    $ 

70.80    $ 

84.69    $ 

80.66    $ 

94.41    $  110.68 

* 

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, 2015 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. 

 
 
 
 
 
 
 
 
(This page has been left blank intentionally.)

CORPORATE 
INFORMATION

EXECUTIVES

Mark J. Enyedy 
President and Chief Executive Officer

Anna Berkenblit, MD
Senior Vice President, Chief Medical Officer

Audrey Bergan 
Senior Vice President, Chief Human Resources Officer

Joseph J. Kenny
Vice President, Acting General Counsel, IP,  
and Secretary

Stacy Coen
Senior Vice President, Chief Business Officer

Susan Altschuller, PhD
Senior Vice President, Chief Financial Officer

Theresa G. Wingrove, PhD
Senior Vice President, Regulatory Affairs and Quality

Thomas Ryll, PhD
Senior Vice President, Technical Operations

ImmunoGen, Inc. 
830 Winter Street |  Waltham, MA 02451 
781–895–0600 |  www.immunogen.com 

DIRECTORS 

CHAIRMAN OF THE BOARD
Stephen C. McCluski 
Former Senior Vice President and Chief Financial 
Officer, Bausch & Lomb, Inc. 

Dean J. Mitchell 
Former Executive Chairman of the Board,  
Covis Pharma Holdings S.a.r.l. 

Kristine Peterson 
Former Chief Executive Officer, Valeritas, Inc. 

Mark J. Enyedy 
President and Chief Executive Officer, ImmunoGen, Inc.

Mark Goldberg, MD 
Former Executive Vice President, Medical and Regulatory 
Strategy, Synageva BioPharma Corp. 

Richard J. Wallace
Former Senior Vice President Research and Development, 
GlaxoSmithKline plc

Stuart A. Arbuckle
Executive Vice President and Chief Commercial Officer, 
Vertex Pharmaceuticals, Inc.

SHAREHOLDER INQUIRIES 

AUDITORS 

Information about ImmunoGen can be found at 
www.immunogen.com. Inquiries related to the Company 
may be directed to the Investor Relations department at 
our headquarters. Communications related to stock and 
transfer requirements, including lost stock certificates and 
change of name or address, should be directed to the 
Transfer Agent. 

Ernst & Young LLP 
Boston, MA 

V I RT UA L A N N UA L M E E T I N G

S TO C K T R A N S F E R AG E N T A N D R EG I S T R A R 

9:00 AM EDT on June 16, 2021 

https://east.virtualshareholdermeeting.com/

IMGN2021

No in-person meeting will be held.

Broadridge Corporate Issuer Solutions, Inc. 
P.O. Box 1342
Brentwood, NY 11717 
Phone: 855–697–4961 
Fax: 215–553–5402 
Email: shareholder@broadridge.com 

We extend our sincere gratitude to the patients, 
families, and medical professionals who participate 
in our clinical trials as we work to meaningfully 
improve the lives of people with cancer.

830 Winter Street
Waltham, MA 02451 
781–895–0600
www.immunogen.com 

NASDAQ: IMGN