Athersys Annual Report 2007

FY2007 Annual Report · Athersys
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Focused 
on 
Innovative 
Medicines 
and 
Outstanding 
Science

Athersys 

2007     Annual Report

Athersys is a clinical stage 

biopharmaceutical company 

with a growing pipeline of 

highly differentiated, potential

best-in-class therapeutics that 

are designed to treat signiﬁcant

and life-threatening diseases. 

The Company’s lead programs 

are in the areas of obesity, 

cardiovascular disease, and bone

marrow transplant support. 

Athersys’ strategic approach

builds on internal and external

knowledge to identify and 

develop highly differentiated

products, as well as enable 

the Company to limit 

development risks and costs.

Highlights

Phase I clinical trial completed 
for lead obesity drug ATHX-105
with favorable results

MultiStem IND authorized 
by FDA for bone marrow 
transplant support

MultiStem IND authorized 
by FDA for myocardial infarction

Completed $65 million ﬁnancing

Successfully transitioned to 
NASDAQ listing (NASDAQ: ATHX)

1

Dear Shareholders,

2007 was a year of important accom-
plishments and a transformative 
one for Athersys. We achieved key
product milestones and corporate
objectives and continued to execute
and advance our strategy of develop-
ing “best-in-class” therapeutics. 
Our goal is to develop differentiated
products in areas of signiﬁcant
unmet clinical need across a range of
therapeutic categories, including
obesity, cardiovascular disease, cancer
treatment support, stroke, and others,
creating value for our shareholders 
in the process. 

In June, we completed a $65-million ﬁnancing 
that signiﬁcantly strengthened our balance sheet and 
provided us with capital to advance key programs.
Simultaneously, we merged into a public company
shell and successfully became a full NASDAQ-listed
company at the end of the year. These were important
steps in enabling us to achieve key corporate and
development goals.

A key therapeutic focus area for the Company is 
developing new ways to treat obesity. According to 
the United States Centers for Disease Control and
Prevention (CDC), for the past three decades or so, 
obesity among adults and children has increased 
dramatically. There also has been a substantial increase
in the rate of obesity in Europe and Asia. 

2

Gil Van Bokkelen Ph.D., Chairman and Chief Executive Ofﬁcer

This serious health condition contributes to a range 
of diseases that represent the major causes of death and
disability in the developed world today: cardiovascular
disease, stroke, diabetes, and certain types of cancer.
There are substantial direct (preventive, diagnostic, and
treatment services) and indirect (morbidity and mortal-
ity) costs associated with obesity. Current approaches to
treating clinical obesity have limited effectiveness, and
there are relatively few new therapeutic approaches in
clinical development. 

Against this backdrop of signiﬁcant need, we are
focused on the development of safe and effective new
medicines to combat obesity. Our most advanced 
clinical candidate, ATHX-105, is a compound devel-
oped by Athersys scientists that acts by stimulating a
key serotonin receptor in the brain known as the 5HT2c
receptor, which is well known to regulate appetite and
food intake. In the summer of 2007, we began our ﬁrst
clinical trial with ATHX-105 – a Phase I trial in the
United Kingdom examining safety and tolerability in
patients. We concluded this clinical trial in early 2008,
with positive results that we believe validate key aspects
of our program and approach – namely that the high
degree of selectivity exhibited by ATHX-105 for the

5HT2c receptor relative to other
serotonin receptors leads to greater
safety and better tolerability, key
factors in achieving drug effective-
ness and patient compliance. 

Following the completion of cer-
tain required non-clinical studies
and regulatory authorization, we
intend to initiate a Phase II clinical
trial of ATHX-105 in the United
States in the second half of 2008
and to report the results of the
study in the ﬁrst half of 2009. 

We believe the potential

applications for MultiStem

are wide ranging, based 

on its apparent ability 

to be used without the 

need for tissue matching 

or immunosuppression, 

as well as its capacity for

large scale production.

We believe the potential 
applications for MultiStem are
wide ranging, based on its
apparent ability to be used with-
out the need for tissue matching
or immunosuppression, as well
as its capacity for large scale 
production. The ability to be
used “off-the-shelf” like a phar-
maceutical product sets it apart
from other cell-based treatment
programs and may enable its
application in a wider variety of
conditions and clinical settings. 

This past year also saw considerable progress in the
development of MultiStem®, our proprietary stem cell
product for the treatment of multiple distinct diseases.
In the fourth quarter, the U.S. Food and Drug
Administration (FDA) authorized two Investigational
New Drug (IND) applications for Phase I clinical trials
in the areas of myocardial infarction and bone marrow
transplant support. In our investigation to date,
MultiStem appears to minimize the inﬂammatory reac-
tion that occurs in response to ischemic events (such as 
a heart attack) or the anti-host immune reaction seen in
graft vs. host disease (GVHD), and promote recovery.

A biologic product that consists of undifferentiated
stem cells obtained from adult bone marrow or other
non-embryonic tissue sources, MultiStem is distinct
from other stem cell therapies in that it may be pro-
duced on a large scale and stored for future clinical use.
Material from a single qualiﬁed donor may be used to
produce hundreds of thousands or more standard clini-
cal doses, which may be banked and stored in frozen
form until needed. The banked supply is extensively
characterized to ensure product consistency and safety.

We may also develop MultiStem for other indications,
such as for treating damage from ischemic stroke, for
which we and our collaborators have seen promising
pre-clinical results. Over time, we intend to explore the
potential for applying MultiStem across a range of
other disease areas, including the treatment of blood
and immune system disorders, autoimmune disease,
orthopedic indications, and others.

Athersys is also developing a novel class of pharmaceu-
ticals designed to block the H3 receptor, a key receptor
that regulates levels of histamine and other neurotrans-
mitters in certain areas of the brain that play a direct
role in regulating cognitive function. These histamine
H3 receptor antagonists are being developed as orally
administered compounds designed to enhance wakeful-
ness and promote cognitive abilities in individuals
suffering from narcolepsy, excessive daytime sleepiness
(EDS), or potentially other conditions, without causing
the side effects seen with alternative approaches, such
as amphetamines and related stimulants. The H3
receptor system has also been shown to play a role in
the regulation of appetite, and we are exploring the
potential of this program in the obesity area as well.

3

Stem cell medicine has been
used successfully for years in
cancer treatment, but the 
potential impact of stem cell 
therapy is far broader.

Scanning electron
micrograph of
hematopoietic stem
cells from human
bone marrow. The
need for tissue
matching and the
inability to produce
stem cells on a large
scale have limited
their clinical beneﬁt.

4

We intend to conduct additional pharmacology and
safety testing of our current compounds under evalua-
tion. If these studies are successful, and depending 
on the availability of capital resources, we will consider
ﬁling an IND for the initiation of clinical trials.

As we made the transition to becoming a public compa-
ny, we also strengthened our board of directors over 
the past year. Following the June ﬁnancing and merger, 
we were pleased to add several new board members,
including Jordan Davis, Managing Partner at Radius
Ventures, Dr. Floyd D. Loop, former Chairman and CEO 
of the Cleveland Clinic Foundation, and Dr. Michael
Sheffery, General Partner at Orbimed Advisors. In
September, Lorin Jeffry Randall was elected to the
Board of Directors and appointed as Chairman of the
Audit Committee. Mr. Randall, a ﬁnancial consultant,
has an extensive background in the healthcare and 
technology industries, with over 20 years of experience
as a senior executive and an independent director of 
private and publicly-traded companies. The collective
experience brought by these new board members – from
business and operational to pharmaceutical and clinical –
will serve us well at this pivotal point in our growth.

Our senior management team remains focused on 
the day-to-day operational issues related to our current
portfolio of therapeutic products in development. 
The successful advancement of these products through
our pipeline puts us in a better position to create 
signiﬁcant shareholder value and ultimately to bring
important new products to market that will address
obesity, damage from cardiovascular disease, cancer
treatment support, and other areas. 

Finally, we achieved two corporate milestones in 2007 –
the registration of shares from the June ﬁnancing and
the completion of our NASDAQ listing in December
under the symbol, “ATHX” – that were critical steps
towards our goal of establishing greater liquidity 
for our shareholders. From a ﬁnancial perspective, we
ended 2007 with a healthy balance sheet and sufﬁcient
cash to fund planned operations into 2010.

In summary we’re pleased with the recent progress in
our key programs and look forward to reaching the 
next level of ﬁnancial and operational performance while
pursuing our mission of developing “best-in-class” 
therapeutics that improve the quality of human life. As
we enter 2008, we will continue to pursue these goals
with the same intensity and focus of prior years to drive
long-term success for the Company and our investors.

We appreciate our shareholders’ continued support and
would like to thank our employees for their ongoing
enthusiasm and commitment to our pursuits. We look
forward to keeping you informed of our progress in
2008 and beyond.

Sincerely, 

Gil Van Bokkelen
Chairman and Chief Executive Ofﬁcer

5

Obesity and Related 
Drug Development Programs

Obesity is a substantial contributing
factor to a range of diseases that 
represent the major causes of death
and disability in the developed world
today. Individuals that are clinically
obese have elevated rates of diabetes,
cardiovascular disease, stroke, and 
certain types of cancer. 

The percentage of individuals who 
are deﬁned as clinically obese has risen
dramatically over the past several
decades. The United States Centers 
for Disease Control and Prevention, 
or CDC, estimates that 66% of all
Americans are overweight, including
more than 30% that are considered
clinically obese. This increase in 
obesity is not limited to adults. The
percentage of young people who are
overweight has more than tripled
since 1980. Among children and teens
aged six to 19 years, 16% (over nine
million young people) are considered
overweight. There has been a similar
dramatic rise in the rate of obesity 
in Europe and Asia. Furthermore, the
cost of this epidemic is signiﬁcant. 
The FDA estimates that the total eco-
nomic cost of obesity is currently about
$117 billion per year in the United
States, including more than $50 billion
in avoidable medical costs. Despite the
magnitude of this problem, current
approaches to clinical obesity are largely
ineffective, and we are aware of rela-
tively few new therapeutic approaches
in clinical development. 

In our portfolio of therapeutic candi-
dates to treat obesity, ATHX-105 is
our lead drug candidate in develop-
ment. ATHX-105 is taken orally and
acts by selectively stimulating a speciﬁc

6

target in the brain that regulates
appetite and food intake – the 5HT2c
receptor, a key serotonin receptor
expressed in the hypothalamus. The
role of this receptor in regulating food
intake is well understood and has been
extensively validated in both animal
models and humans. Drugs that stimu-
late this receptor, or act as “agonists,”
have been shown to be highly effective
at reducing appetite and causing weight
loss. We believe that ATHX-105 may
prove to be a “best-in-class” drug 
for obesity given its well-validated
mechanism of action, exceptional
selectivity and favorable, emerging
safety and tolerability proﬁle. 

Other drugs, such as fenﬂuramine 
and dexfenﬂuramine, are non-selective
agonists of the 5HT2c receptor and
because of their limited selectivity
have undesirable biological activity at
other serotonin receptors. Although
these drugs were regarded as being
very effective in regulating appetite
and causing weight loss, their use was
linked to an increased incidence of
heart valvulopathy, a serious cardio-
vascular safety issue. As a result these
drugs were subsequently withdrawn
from the market. However, over the
past few years, evidence has accumu-
lated indicating that the stimulation
of the 5HT2b receptor, another sero-
tonin receptor expressed in the heart,
is responsible for causing drug-
induced valvulopathy. Further, the
growing body of research indicates
that the stimulation of the 5HT2c
receptor with its desirable weight loss
effects is distinct and separable from
the stimulation of 5HT2b, or other
serotonin receptors that may cause
unwanted side effects, like dizziness,
nausea or headaches. 

ATHX-105 has been extensively char-
acterized pre-clinically and exhibits
exceptional selectivity for the 5HT2c
receptor relative to the problematic
5HT2b receptor based on receptor
binding afﬁnity assays, the gold stan-
dard for evaluating drug afﬁnity and
selectivity. Speciﬁcally, ATHX-105 
is roughly 235 times more selective 
to the 5HT2c receptor relative to the
5HT2b receptor, making it about
470-fold more selective than the
active agent from fenﬂuramine and
dexfenﬂuramine. Additionally,
ATHX-105 is approximately 40-fold
more selective for the 5HT2c receptor
relative to the 5HT2a receptor, a
receptor that is thought to cause cen-
tral nervous system-related side effects
when sufﬁciently stimulated, such as
dizziness, nausea, and headache. These
side effects could limit drug tolerabil-
ity and effectiveness, as well as lead 
to reduced patient compliance.

In the summer of 2007 we began a
Phase I clinical trial for ATHX-105 
to evaluate safety and tolerability. 
The trial was conducted in the United
Kingdom, working with an estab-
lished contract research organization
that has extensive experience in 
conducting such trials. 

The ATHX-105 Phase I clinical trial
was a randomized, double-blinded,
placebo-controlled study conducted in
healthy male and female volunteers 
to evaluate the safety, tolerability and
pharmacokinetics of the compound.
The study was carried out in two 
parts – a single ascending dose study
and a multiple ascending dose study,
in which patients received drug or

The combination of a well-
validated mechanism of action
and good tolerability ultimately
positions us to deliver a better,
safer obesity drug. 

7

placebo for up to seven days. In total,
107 subjects were evaluated. The
study, completed in January 2008,
demonstrated that ATHX-105 is well
tolerated. The maximum tolerated
dose was 100 milligrams. The drug
produced only transient and modest
side effects at higher dose levels, with
no clinically signiﬁcant effects on 
any hematology or clinical chemistry
parameters at any dose. In addition,
there were no serious or severe adverse
events, and no discontinuations from
the study due to adverse events. These
results further validate an important
aspect of this program – that higher
selectivity for 5HT2c relative to other
serotonin receptors can result in better
drug tolerability and fewer side effects.

Based on these results, Athersys
intends to initiate a Phase II trial for
ATHX-105 during the second half 
of 2008, upon obtaining appropriate
regulatory approval from the FDA.
Athersys’ objective in its Phase II
study program is to further demon-
strate safety, establish efﬁcacy, and
further understand the dose range for
ATHX-105. 

In addition to ATHX-105, the 
Company plans to advance its other
obesity projects, which are an impor-
tant part of the pipeline. Athersys 
is focused on the development of next
generation 5HT2c agonists, as well 
as interested in exploring formulation 
of ATHX-105 to further enhance 
its proﬁle. 

The Company is also focused on
exploring other biological mechanisms
of action to combat obesity. Some of
these programs could potentially be
complementary to our 5HT2c agonist
program, or have relevance in other
therapeutic areas of interest. 

8

H3 Antagonist Program

Athersys is developing a novel class of
pharmaceuticals aimed at blocking the
H3 receptor, a key receptor in the
brain that affects levels of histamines
and other neurotransmitters to regu-
late certain neurological functions,
including appetite and food intake, as
well as promote enhanced cognition,
wakefulness, and learning. We are
exploring the potential relevance of
H3 receptor antagonists in multiple
areas, including evaluating compounds
we are developing for application in
the treatment of obesity. 

In addition to their potential relevance
in treating obesity, H3 receptor antag-
onists have been shown to increase
histamine release in speciﬁc areas of 
the brain and improve wakefulness,
attention, and learning. Individuals
who suffer from conditions such 
as narcolepsy or others that result in
excessive daytime sleepiness (EDS) may
experience persistent tiredness and lack
of energy, ultimately affecting their
ability to carry out routine tasks and
impairing their quality of life. Today
more than 100,000 individuals in the
U.S. suffer from narcolepsy or EDS. 

Similarly, individuals with attention 
or cognitive disorders may suffer from
an inability to focus, solve problems,
process information, communicate, 
and may have memory impairment.
Attention and cognitive disorders
include ADHD, Alzheimer’s disease
and other forms of dementia. It is 
estimated that in the seven major phar-
maceutical markets alone (including
the United States, France, Germany,
Italy, Spain, the United Kingdom, and
Japan) nearly 23 million children suffer
from ADHD and that 60% maintain
the disorder into adulthood. 

Currently marketed drugs for these
disorders have side effects and may
not adequately address the clinical
need or have safety and substance
abuse issues associated with them. 

As a result, we believe that a signiﬁ-
cant market opportunity exists to
develop novel pharmaceutical products
that overcome these issues. 

Our histamine H3 receptor antago-
nists represent a new class of drugs
that we believe could have an
improved efﬁcacy and safety proﬁle
relative to existing drugs used 
for the treatment of sleep disorders. 

Our program is aimed at the develop-
ment of non-stimulant, non-addictive,
orally administered compounds for
the treatment of narcolepsy or other
conditions related to excessive day-
time sleepiness.

In pre-clinical testing of one of our
more advanced compounds in a well-
validated rodent sleep model, our
compound signiﬁcantly enhanced
wakefulness without causing apparent
adverse events. In comparison to 
currently marketed products such as
Provigil (modaﬁnil) or caffeine, 
the Athersys compound was far more
potent, achieving a comparable or 
better effect on wakefulness at sub-
stantially lower doses. In addition,
this compound did not appear to
cause the excessive rebound sleepiness
that is a characteristic of other agents
used to promote wakefulness, such 
as amphetamines.

We intend to continue the study of H3
antagonists for potential applications
in treating narcolepsy, excessive day-
time sleepiness, and certain attention
or cognitive disorders. In addition, we
plan to conduct additional pharmacol-
ogy and safety testing of our current
compounds under evaluation. If these
studies are successful, and depending
on the allocation of capital resources 
for existing programs, we will consider 
ﬁling an IND for the initiation of 
clinical trials in these indications.

We are committed to developing
innovative new medicines 
that extend and enhance the
quality of human life.

9

MultiStem Programs
A Novel Stem Cell Therapy

Stem cells are specialized cells that are
responsible for forming the tissues and
organs in the body, and helping the
body recover from injury or disease.
There are a variety of stem cells in the
body, including those that give rise to
speciﬁc cells of the blood and immune
system, nervous system, bone and 
connective tissue, muscle tissue, blood
vessels and others. Certain stem cells
also have the ability to form multiple
cell types, as well as produce a range of
factors, such as proteins or cytokines,
that can reduce inﬂammation and limit
tissue damage, as well as help promote
tissue repair and recovery.

We are developing MultiStem®, a 
proprietary stem cell product for the
treatment of multiple disease indica-
tions. MultiStem is a biologic product
that is manufactured from human stem
cells obtained from adult bone marrow
or other non-embryonic sources. After
cells are isolated from a qualiﬁed donor,
they are processed and undergo a well-
deﬁned expansion process that enables
large scale production – material from a
single donor may be used to produce
hundreds of thousands of doses or more,
which are then stored frozen until need-
ed. In contrast to other stem cell types
which may only be produced in limited
quantities when isolated from the body,
MultiStem may be produced on an
industrial scale – making widespread
clinical use of stem cells possible for 
the ﬁrst time.

Based on research to date, MultiStem
may be used safely without having 
to match the donor and recipient, in 
contrast to what is required for a 
typical bone marrow or hematopoietic
stem cell transplant. Additionally,

10

MultiStem has the ability to form 
multiple cell types, and produce a
range of factors that can reduce inﬂam-
mation and tissue repair and recovery.

As a result of these characteristics – 
the ability to produce MultiStem on a
large scale, administer it without
requiring tissue matching or giving 
the patient immunosuppressive drugs,
and the apparent ability to deliver 
therapeutic beneﬁt through multiple 
mechanisms, we believe that MultiStem
represents a potential breakthrough 
in stem cell medicine – and also 
represents another “best-in-class”
opportunity. We are committed to
exploring the therapeutic potential 
of MultiStem in a range of areas,
including cancer treatment support,
cardiovascular disease, stroke, autoim-
mune disease, and other conditions. 

We believe MultiStem has multiple
potential applications that we can devel-
op efﬁciently and in parallel. In late
2007, we received FDA authorization
for two Investigational New Drug 
applications (INDs) involving the initial
clinical application of MultiStem. 
The ﬁrst IND is for a Phase I clinical
trial involving the use of MultiStem 
for cancer treatment support in patients
receiving a bone marrow or hemato-
poietic stem cell transplant, and the
second is for using MultiStem to 
treat damage caused by a myocardial
infarction or heart attack.

MultiStem for Cancer
Treatment Support

For many types of cancer, such as
leukemia or other blood-borne cancers,
treatment typically involves radiation
therapy or chemotherapy, alone or in

combination. Such treatment can 
substantially deplete the cells of the
blood and immune system, by reduc-
ing the number of stem cells in the
bone marrow from which they arise.
The more intense the radiation treat-
ment or chemotherapy, the more severe
the resulting depletion of the bone
marrow, blood, and immune system.
However, other tissues may also be
affected, such as cells in the digestive
tract and in the pulmonary system. The
consequences may include severe ane-
mia, loss of immune system function,
signiﬁcant reduction in digestive capac-
ity, and other problems, which could
lead to signiﬁcant disability or death. 

One strategy for treating the depletion
of bone marrow is to perform a periph-
eral blood stem cell transplant or a 
bone marrow transplant. This approach
may augment the patient’s ability to
form new blood and immune cells and
provide a signiﬁcant survival advantage.
However, ﬁnding a closely matched
donor is frequently difﬁcult or even
impossible. Even when such a donor is
found, in many cases there are immuno-
logical complications, such as GVHD,
which may result in death or serious
disability. 

Working with outside experts in the
stem cell and bone marrow transplanta-
tion ﬁeld, we have studied MultiStem 
in animal models of radiation therapy
and GVHD. MultiStem has been shown
to be non-immunogenic, even when
administered without the genetic
matching that is typically required for
conventional bone marrow or stem 
cell transplantation. Furthermore, in
animal model systems testing immune

MultiStem allows us to efficiently 
pursue multiple, high-value 
commercial and therapeutic 
opportunities from a single 
product platform.

11

reactivity of T-cells against unrelated
donor tissue, MultiStem has been
shown to suppress the T-cell-mediated
immune responses that are an impor-
tant factor in causing GVHD.
MultiStem-treated animals also dis-
played a signiﬁcant increase in survival
relative to controls, as well as better
overall health. As a result, we believe
that the administration of MultiStem
in conjunction with or following stan-
dard bone marrow or hematopoietic
stem cell transplantation may have the
potential to reduce the incidence or
severity of complications and may
enhance other important functions,
such as gastrointestinal capacity. 

In the fourth quarter of 2007, we
announced authorization by the FDA 
of our IND for the application of
MultiStem in support of bone marrow
transplantation for the treatment of cer-
tain cancers of the blood and immune
system. We intend to initiate a Phase I
clinical trial in 2008 examining the
safety and tolerability of MultiStem 
in patients receiving a bone marrow
transplant related to their treatment for
hematologic malignancy. The trial will
be an open label, multicenter trial.

MultiStem for Acute
Myocardial Infarction

Myocardial infarction is one of the
leading causes of death and disability
in the United States. It is caused by the
blockage of one or more arteries that
supply blood to the heart. Such block-
ages may be caused, for example, by
the rupture of an atherosclerotic
plaque. The loss of oxygen and nutri-
ents downstream of a blockage can lead
to signiﬁcant damage to the heart tis-
sue and consequential loss of function.
Despite advancements in treatment
and patient care, myocardial infarction
remains a leading cause of death and
disability in the United States and the
rest of the world.

12

Working with leading cardiovascular
research centers, such as the Cleveland
Clinic, the University of Minnesota 
and others, we have conducted pre-clin-
ical studies in well-validated animal
models of acute myocardial infarction.
Investigators have demonstrated that
the administration of allogeneic
MultiStem using a catheter delivery
system following a myocardial infarc-
tion resulted in signiﬁcant functional
improvement in cardiac output and
other functional parameters compared
with animals that received placebo or
no treatment. 

We intend to initiate an open label,
multicenter Phase I clinical trial of
MultiStem for the treatment of acute
myocardial infarction. The study 
will be conducted at several leading
cardiovascular treatment centers
beginning in 2008. This trial is 
being conducted with our partner
Angiotech Pharmaceuticals. 

MultiStem for Stroke

A third focus of our MultiStem program
is for the treatment of neurological
injury as a result of ischemic stroke,
which accounts for approximately 80%
of all strokes. Recent progress toward the
development of safer and more effective
treatments for ischemic stroke has been
disappointing. In the United States
alone there are more than 700,000 new
stroke patients annually; according to
the CDC, there has been little progress
toward the development of treatments
that improve the prognosis for stroke
victims. The only FDA-approved drug
currently available for ischemic stroke 
is the anti-clotting factor, tPA, which
must be administered to the patient
within roughly three hours of the onset
of the stroke. Administration of tPA
after this time frame is not recommend-
ed, since it can cause bleeding or even
death. Given this limited therapeutic
window, it is estimated that less than
5% of ischemic stroke victims currently
receive treatment with tPA. 

In pre-clinical studies, signiﬁcant 
functional improvements have been
observed in rodents that have under-
gone an experimentally induced stroke,
or that have incurred signiﬁcant neuro-
logical damage as a result of neonatal
hypoxic ischemia, and then received
treatment with MultiStem. Through
research conducted by collaborators 
at the Medical College of Georgia and
presented at the annual American
Academy of Neurology meeting in
April 2006, we observed that adminis-
tration of MultiStem even one week
after a surgically induced stroke results
in substantial long-term therapeutic
beneﬁt, as evidenced by the improve-
ment of treated animals compared with
controls in a battery of tests examining
mobility, strength, ﬁne motor skills,
and other aspects of neurological func-
tional improvement. These results 
have been conﬁrmed in subsequent
pre-clinical studies that demonstrate
that MultiStem treatment is well 
tolerated, does not require immuno-
suppression, and results in a robust 
and durable therapeutic beneﬁt even
when administered one week after 
the initial stroke event. 

Upon completion of remaining pre-
clinical safety studies, we intend to
submit an IND for this application in
2008. The subsequent initiation of a
clinical trial will depend on obtaining
FDA authorization of this IND, and
the availability of capital resources to
complete the study. 

We believe that MultiStem could 
have broad potential to treat a range of
conditions. In addition to the above
programs, we are collaborating or
intend to collaborate with other highly
qualiﬁed investigators to evaluate the
potential beneﬁts of MultiStem in
other disease indications, such as vari-
ous blood and immune deﬁciencies,
certain autoimmune diseases and other
potential indications. 

Learning from the efforts of 
others, and by employing a fast-
follower approach where 
appropriate, we can control 

13

Development Status 
of Key Programs

Discovery

Preclinical

IN D/C TA

P hase I

P hase II

P hase III

N D A/B L A

ATHX-105 obesity

Multistem BM Transplant

Multistem AMI

Multistem Stroke

H3 Antagonist Program

During 2007, Athersys completed a
Phase I trial for our leading drug can-
didate, ATHX-105, for obesity. We
intend to initiate a Phase II clinical
trial in the United States that will
examine safety and effectiveness in
clinically obese patients in the second
half of 2008, and to report the results
in the ﬁrst half of 2009. In addition to
ATHX-105, we have a portfolio of
other compounds that we are develop-
ing as potential treatments for obesity.

14

In the fourth quarter of 2007, our 
ﬁrst two INDs for MultiStem, our
proprietary non-embryonic stem 
cell product, were submitted and
authorized by the FDA in the areas of
bone marrow transplant support and
acute myocardial infarction. We are
also independently developing novel
orally active pharmaceutical products
designed to block the H3 receptor 
for the treatment of obesity or certain
central nervous system disorders,
including sleep disorders such as 
narcolepsy or excessive daytime sleepi-
ness, and other potential indications
such as attention deﬁcit hyperactivity
disorder, or ADHD.

Through the application of our 
proprietary technologies, we have
established a pipeline of highly differ-
entiated, potential “best-in-class”
therapeutic candidates. This chart
presents a snapshot, as of the ﬁrst
quarter 2008, of drugs in develop-
ment from Athersys. We will
continue to identify opportunities to
develop drug therapies that we believe
are innovative and offer signiﬁcant
beneﬁt to patients, as well as create
value for our shareholders.

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

(Mark One)
¥

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)
OF THE SECURITIES EXCHANGE ACT OF 1934
For the fiscal year ended December 31, 2007

OR

n

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

to

Commission file number 0-52108

Athersys, Inc.

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of
incorporation or organization)

3201 Carnegie Avenue, Cleveland, Ohio
(Address of principal executive offices)

20-4864095
(I.R.S. Employer
Identification No.)

44115-2634
(Zip Code)

Registrant’s telephone number, including area code
(216) 431-9900
Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class

Name of Each Exchange on Which Registered

Common Stock, par value $.001 per share

NASDAQ Stock Market LLC

Securities registered pursuant to Section 12(g) of the Act:
None

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

Act. Yes n

No ¥

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

Act. Yes n

No ¥

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Sections 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. Yes ¥

No n

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and
will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference
in Part III of this Form 10-K or any amendment to this Form 10-K. ¥

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

Accelerated filer ¥

Smaller reporting company n

Non-accelerated filer n
(Do not check if a smaller reporting company)

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes n
The aggregate market value at June 29, 2007, the last day of the registrant’s most recently completed second quarter, of shares

No ¥

of the registrant’s common stock (based upon the closing price per share of $7.75 of such stock as quoted on the OTC
Bulletin Board on such date) held by non-affiliates of the registrant was approximately $106 million.

The registrant had 18,927,988 shares of common stock outstanding on March 13, 2008.

Documents Incorporated By Reference.
Part III of this Annual Report on Form 10-K incorporates by reference certain information from the registrant’s definitive

Proxy Statement with respect to the 2008 Annual Meeting of Stockholders.

TABLE OF CONTENTS

PART I

Item 1.
Business . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 1A. Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 1B. Unresolved Staff Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 2.
Legal Proceedings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 3.
Submission of Matters to a Vote of Security Holders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 4.
Item 4A. Executive Officers of the Registrant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PART II

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

of Equity Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 6.
Selected Financial Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations . . .
Item 7A. Quantitative and Qualitative Disclosures About Market Risk . . . . . . . . . . . . . . . . . . . . . . . . .
Financial Statements and Supplementary Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 8.
Item 9.
Changes in and Disagreements with Accountants on Accounting and Financial Disclosures . .
Item 9A. Controls and Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 9B. Other Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PART III

Item 10. Directors, Executive Officers and Corporate Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 11. Executive Compensation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Security Ownership of Certain Beneficial Owners and Management and Related Stockholder
Item 12.
Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 13. Certain Relationships and Related Transactions, and Director Independence . . . . . . . . . . . . . .
Principal Accountant Fees and Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Item 14.

3
18
33
33
33
33
33

35
36
37
48
49
71
71
71

71
72

72
72
72

Item 15. Exhibits and Financial Statement Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

73

PART IV

2

ITEM 1. BUSINESS.

PART I

We are a biopharmaceutical company engaged in the discovery and development of therapeutic product

candidates designed to extend and enhance the quality of human life. Through the application of our
proprietary technologies, we have established a pipeline of therapeutic product development programs in
multiple diseases. In 2007, we advanced our lead program for treating obesity into clinical development. We
also advanced two additional programs in 2007, receiving authorization for Investigational New Drug
applications, or INDs, for treatment of acute myocardial infarction, or AMI, and the complications (e.g., graft
versus host disease) associated with hematopoietic stem cell/bone marrow transplantation for certain hemato-
logic malignancies. We have additional programs in discovery and preclinical development for the treatment of
ischemic stroke and certain cognitive or attention disorders. Our ability to advance these programs will depend
on the success of our ongoing discovery and development efforts, obtaining necessary regulatory approvals and
available capital resources.

Our lead product candidate is ATHX-105, which is a treatment for obesity that acts by stimulating the
5HT2c receptor, a key neurotransmitter receptor in the brain that regulates appetite. ATHX-105 is administered
orally and has been shown in preclinical testing in animal models to reduce food intake and body weight by
suppressing appetite without appearing to cause the adverse side effects that have been observed with other
weight loss drugs. Results from clinical trials we conduct in humans may differ from our preclinical results.

In July 2007, we initiated a Phase I clinical trial for ATHX-105 in the United Kingdom. The primary
objective of the Phase I clinical trial was to assess the short-term safety of ATHX-105 and to establish an
appropriate dose range for subsequent clinical studies that will be conducted in order to assess safety and
effectiveness. The Phase I clinical trial, which included 107 subjects, was completed in January 2008. The
maximum tolerated dose for ATHX-105 was determined to be 100 mg. ATHX-105 was generally well-
tolerated at dose levels below 100 mg. The drug was well-absorbed, resulting in good drug exposures
following oral administration. There were no severe or serious adverse events observed in the clinical trial, no
negative effects on cardiovascular, hematology or other clinical parameters, and no discontinuations due to
adverse events. Following a detailed analysis of the results of the clinical trial, the completion of certain
required non-clinical studies and regulatory approval, we intend to initiate a Phase II clinical trial in the
United States that will examine safety and effectiveness in clinically overweight or obese patients. In addition
to ATHX-105, we have a portfolio of other compounds that we are developing as potential treatments for
obesity.

We are also independently developing novel orally active pharmaceutical products for the treatment of
central nervous system disorders, including sleep disorders such as narcolepsy or excessive daytime sleepiness,
and other potential indications such as attention deficit hyperactivity disorder and other cognitive disorders.
These programs are focused on the development of histamine H3 receptor antagonist compounds that act by
elevating levels of neurotransmitters in the sleep and cognitive centers of the brain and stimulating neurolog-
ical tone, resulting in an enhanced state of wakefulness and cognition, without causing hyperactivity or
addiction.

In addition to our pharmaceutical development programs, we are developing MultiStem», a proprietary

stem cell product for the treatment of multiple disease indications. MultiStem is a biologic product that is
manufactured from human stem cells obtained from adult bone marrow or other nonembryonic tissue sources.
After cells are isolated from a qualified donor, the MultiStem product may be produced on a large scale for
future clinical use and stored in frozen form until needed. We believe that MultiStem may potentially be used
to treat a range of disease indications, with each indication representing a distinct product development
program requiring separate clinical trials. In May 2006, we entered into a product co-development collabora-
tion with Angiotech Pharmaceuticals, Inc., or Angiotech, to jointly develop and ultimately market MultiStem
for the treatment of damage caused by myocardial infarction and peripheral vascular disease. We are also
independently developing MultiStem for hematopoietic stem cell, or HSC transplant support, ischemic stroke

3

and potentially other disease indications. We retain the commercial rights to these programs and other potential
applications of MultiStem.

In addition to our current product development programs, we developed our patented RAGE technology
that provides us with the ability to produce human cell lines that express specific, biologically well validated
drug targets without relying upon cloned and isolated gene sequences. While our RAGE technology is not a
product, it is a commercial technology that we are successfully applying for the benefit of our partners and
that we have also used for our own internal drug development programs. Modern drug screening approaches
typically require the physical isolation and structural modification of a gene of interest (an approach referred
to as gene cloning) in order to create a cell line that expresses a drug target of interest. Researchers may then
use the genetically modified cell line to identify pharmaceutical compounds that inhibit or stimulate the target
of interest. The RAGE technology enables us to turn on or amplify the expression of a drug target without
having to physically clone or isolate the gene. In effect, the technology works through the random insertion of
tiny, proprietary genetic switches that randomly turn genes on without requiring their physical isolation, or any
advance knowledge of their structure. This technology provides us with broad freedom to work with targets
that may be inaccessible to most other companies as a result of intellectual property restrictions on the use of
specific cloned and isolated genes. Over the past several years, we have produced cell lines that express drug
targets in a range of disease areas such as metabolic disease, infectious disease, oncology, cardiovascular
disease, inflammation, and central nervous system disorders. Many of these were produced for drug
development programs at major pharmaceutical companies that we have collaborated with, such as our
ongoing collaboration with Bristol-Myers Squibb, and some have been produced for our internal drug
development programs.

Business Strategy

Our principal business objective is to discover, develop, and commercialize novel therapeutic products for

disease indications that represent significant areas of clinical need and commercial opportunity. The key
elements of our strategy are outlined below.

(cid:129) Efficiently develop product candidates in established areas of significant clinical need. We will

continue to develop our leading product candidates (e.g., ATHX-105 and MultiStem) using a “fast
follower” approach, thereby mitigating risk and reducing costs. This approach allows us to leverage
others’ prior clinical efforts and validation in the development of best-in-class product candidates with
differentiated profiles. Our intention is to develop our products for ultimate commercialization by us,
our partners or licensees after they have received approval from the United States Food and Drug
Administration, or FDA.

(cid:129) Apply our proprietary technologies toward the rapid identification, validation, and development of

therapeutic product candidates. We will continue to use our proprietary technologies to identify and
validate therapeutic product candidates. We believe our technologies, including RAGE and MultiStem,
provide us a competitive advantage in drug discovery and product development by allowing us to move
products quickly from the discovery phase into clinical trials. We will select candidates for internal
development based on several factors, including the required regulatory approval pathway and the
potential market into which the product may be sold, and our ability to feasibly fund development
activities through commercialization and marketing of the approved product.

(cid:129) Enter into licensing or co-development arrangements for certain product candidates. We intend to

license certain of our product candidates to, or co-develop them with, qualified collaborators to broaden
and accelerate our product development and commercialization efforts. In order to enhance the value of
our product candidates in these potential licensing or collaboration arrangements, we plan to internally
develop our product candidates through at least Phase II clinical trials whenever possible. We anticipate
that this strategy will help us to enhance our return on product candidates for which we enter into
collaborations through the receipt of strategic equity investments, license fees, milestone payments, and
profit sharing or royalties.

4

(cid:129) Continue to expand our intellectual property portfolio. Our intellectual property is important to our

business and we take significant steps to protect its value. We have an ongoing research and
development effort, both through internal activities and through collaborative research activities with
others, which aims to develop new intellectual property and enable us to file patent applications that
cover new applications of our existing technologies or product candidates, including MultiStem.

(cid:129) Out-license non-core applications of our technologies. Certain elements of our technologies, such as

their application toward the development of novel diagnostics or their use for the analysis, characteriza-
tion or production of certain types of therapeutic product candidates, may not be relevant to the key
elements of our corporate strategy. We believe these applications may have significant potential value,
however, and can provide capital to us that can be applied to our other development efforts. Where
appropriate, we may seek to license non-core applications of our technologies to others to realize this
value.

Our Current Programs

By applying our core technologies and capabilities, we have established drug development programs in
the areas of obesity and central nervous system disorders. In addition, applying our proprietary cell therapy
platform, MultiStem, we have established therapeutic product development programs in the areas of cardiovas-
cular disease, HSC transplant support and ischemic stroke. We advanced our first program into clinical
development in 2007 and intend to advance two or more additional programs into clinical development in
2008.

Pharmaceutical Programs

ATHX-105 for Obesity

Obesity is a substantial contributing factor to a range of diseases that represent the major causes of death

and disability in the developed world today. Individuals that are clinically obese have elevated rates of
cardiovascular disease, stroke, certain types of cancer and diabetes. The percentage of individuals who are
defined as clinically obese has risen dramatically over the past several decades. According to the United States
Centers for Disease Control and Prevention, or CDC, the incidence of obesity in the United States has
increased at an epidemic rate during the past 20 years. CDC now estimates that 66% of all Americans are
overweight, including more than 30% that are considered clinically obese. This increase is not limited to
adults. The percentage of young people who are overweight has more than tripled since 1980. Among children
and teens aged six to 19 years, 16% (over nine million young people) are considered overweight. There has
been a similar dramatic rise in the rate of obesity in Europe and Asia. Furthermore, the cost of this epidemic
is significant. The FDA estimates that the total economic cost of obesity is currently about $117 billion per
year in the United States, including more than $50 billion in avoidable medical costs. Despite the magnitude
of this problem, current approaches to clinical obesity are largely ineffective, and we are aware of relatively
few new therapeutic approaches in clinical development.

We are developing novel pharmaceutical treatments for obesity. Our most advanced drug development
candidate is ATHX-105, a compound we discovered internally and have extensively analyzed and validated in
preclinical studies. In July 2007, we initiated a Phase I clinical trial for ATHX-105 in the United Kingdom.
The Phase I clinical trial had a standard design evaluating safety and tolerability of single dose administration,
dose escalation, and maximum tolerated dose, followed by a study examining the effect of once-daily
administration of ATHX-105 to healthy overweight or obese individuals for a period of one week. Participants
in the study had a target body mass index of 25 to 35, and included groups at several different dose levels or
placebo. Safety monitoring included the assessment of various cardiovascular parameters. The primary
objective of the Phase I clinical trial was to assess the short-term safety and tolerability of ATHX-105 and to
establish an appropriate dose range for subsequent clinical studies that will be conducted in order to assess
safety and effectiveness. The Phase I clinical trial, which included 107 subjects, was completed in January
2008. The maximum tolerated dose for ATHX-105 was determined to be 100 mg, and the results from the
clinical trial indicate that ATHX-105 was generally well-tolerated at dose levels below 100 mg. The drug

5

appeared to be well-absorbed, resulting in good drug exposures following oral administration. There were no
severe or serious adverse events observed in the clinical trial, no negative effects on cardiovascular,
hematology or other clinical parameters, and no discontinuations due to adverse events. Following a detailed
analysis of the results of the clinical trial, the completion of certain required non-clinical studies and
regulatory approval, we intend to initiate a Phase II clinical trial in the United States that will examine safety
and effectiveness in clinically obese patients.

As a result of the work that we have completed to date, we believe that ATHX-105 represents a potential

“best-in-class” obesity drug based on its well validated mechanism of action, as well as the potency and
overall safety profile we have observed in preclinical studies and our recently completed phase I clinical trial.
We are developing ATHX-105 as an orally administered pill to regulate appetite and reduce food intake in
clinically obese individuals, defined as those individuals with a body mass index greater than 30. In addition
to ATHX-105, we are developing a diverse portfolio of back-up compounds that act by the same mechanism
as ATHX-105, as well as complementary obesity programs that act according to different biological
mechanisms of action.

ATHX-105 is designed to act by stimulating a key receptor in the brain that regulates appetite and food

intake — the 5HT2c receptor. The role of this receptor in regulating food intake is well understood in both
animal models and humans. In 1996, Wyeth Pharmaceuticals launched the anti-obesity drug Redux»
(dexfenfluramine), a non-specific serotonin receptor agonist that was used with the stimulant phentermine in a
combination commonly known as “fen-phen.” This diet drug combination gained rapid and widespread
acceptance in the clinical marketplace, and was shown to be highly effective at regulating appetite, reducing
food intake, and causing weight loss. Unfortunately, in addition to stimulating the 5HT2c receptor, Redux also
stimulated the 5HT2b receptor that is found in the heart. The activation of 5HT2b by Redux is believed to
have caused significant cardiovascular problems in a number of patients and, as a result, Redux» was
withdrawn from the market in 1997. In 1996, doctors wrote 18 million monthly prescriptions for drugs
constituting the fen/phen combination. In that same year, these drugs generated sales of greater than
$400 million, serving as a benchmark for the substantial market opportunity for an effective drug to treat
clinical obesity.

Since the withdrawal of Redux from the market, several groups have published research that implicates

stimulation of the 5HT2b receptor as the underlying cause of the cardiovascular problems. These findings
suggest that highly selective compounds that stimulate the 5HT2c receptor, but that do not appreciably
stimulate the 5HT2b receptor, could be developed that maintain the desired appetite suppressive effects without
the cardiovascular toxicity. Recently, Arena Pharmaceuticals developed a selective 5HT2c agonist, Lorcaserin,
which exhibits significant selectivity for the 5HT2c receptor relative to the 5HT2b receptor. In a Phase II
clinical trial conducted by Arena Pharmaceuticals, Lorcaserin was demonstrated to reduce appetite and cause
statistically significant weight loss in patients that were administered the drug for a period of three months,
without causing any apparent cardiovascular effects. However, at higher doses the drug has been shown to
cause dizziness, nausea and headaches, which may be a consequence of its apparently more limited selectivity
for the 5HT2c receptor relative to another serotonin receptor expressed in the brain, the 5HT2a receptor.
Currently, Lorcaserin is undergoing a large scale, two-year Phase III clinical trial that is designed to evaluate
safety, including cardiovascular safety, and effectiveness at causing weight loss in patients that are adminis-
tered Lorcaserin for a period of one year. Lorcaserin is being administered twice per day at a dosage level that
is half the level previously observed to cause unacceptable levels of dizziness, nausea and headaches in prior
clinical studies.

We initiated a drug development program focused on creating potent and selective compounds that

stimulate the 5HT2c receptor, but that avoid the 5HT2b receptor and other receptors, such as 5HT2a. Our
specific goal is to develop an orally administered pill that reduces appetite by stimulating the 5HT2c receptor,
but that does not stimulate the 5HT2b receptor, the 5HT2a receptor, or other receptors that could cause
adverse side effects. Based on extensive preclinical studies that we have conducted with ATHX-105, it has
been shown to be a highly potent and selective compound. We believe that the superior selectivity displayed
by ATHX-105 for the 5HT2c receptor relative to both the 5HT2b receptor and the 5HT2a receptor will result
in a cleaner safety profile in clinical studies, which appears to be supported by the results of our recently

6

completed phase I clinical trial, and may allow us to achieve better efficacy, as well as a more convenient
dosing schedule than other 5HT2C agonist programs.

In preclinical testing in rodents, obese animals that received once-daily doses of ATHX-105 exhibited a

57% reduction in daily food intake as compared to animals receiving placebo alone. In addition, after
receiving once-daily doses of ATHX-105 for two weeks, these animals weighed 10% less than the animals that
were treated with placebo alone. The effect was dose proportional, and animals that received increasing doses
of ATHX-105 showed progressively greater weight loss.

In dogs, oral administration of a low dose (0.1mg/kg) of ATHX-105 resulted in a short-term reduction of

food intake of approximately 50%, while animals receiving a 10-fold higher dose (1.0 mg/kg) of ATHX-105
exhibited a complete cessation of short-term food intake that resolved over time as the drug cleared. Based
upon these results, and the results of other studies that we have conducted, we calculate the effective dose
range in dogs to be approximately 0.1 to 0.2 mg/kg.

In extensive preclinical testing in both dogs and monkeys, ATHX-105 appeared to be safe and well
tolerated, even when administered at doses substantially higher than those that caused a significant reduction
in food intake. In dogs, the maximum tolerated dose was established at 36 mg/kg, a dose level approximately
180 to 360 times higher than the effective dose range observed in short-term food intake studies. We also
studied the safety profile of ATHX-105 in cynomolgous monkeys, administering doses for two weeks that are
40 to 50 times greater than the expected effective dose levels in humans, which were well tolerated with no
signs of adverse effects.

In addition, we are developing other compounds that are designed to stimulate the 5HT2c receptor with
greater potency and/or specificity than ATHX-105. Some of these compounds have demonstrated significant
reductions in food intake in rodent models. We plan to subject these compounds to further safety and efficacy
testing in animals while we continue to develop ATHX-105. Furthermore, we have created cell lines that
express obesity targets that are distinct from 5HT2c by utilizing our other technologies and have screened for
compounds using our compound library that are designed to significantly reduce food intake by acting against
these targets. Although these compounds are at earlier stages of preclinical development, we believe they
represent promising opportunities for future development.

H3 Antagonists for the Treatment of Sleep Disorders and Certain Other Cognitive Disorders

In addition to our obesity program, we are developing a class of pharmaceuticals that are designed to

enhance wakefulness and promote cognitive abilities. Individuals that suffer from narcolepsy or other
conditions that result in excessive daytime sleepiness, or EDS, may experience persistent tiredness and lack of
energy. As a result, such individuals may experience significant difficulty in performing certain tasks, and may
suffer an impaired quality of life. More than 100,000 individuals in the U.S. suffer from narcolepsy or EDS.
Historically, narcoleptics were treated with amphetamines and related stimulants that had substantial side-
effects, but more recently have been prescribed Provigil (modafinil). This compound works by an unknown
mechanism, but appears to be relatively free of the stimulant side-effects of amphetamines. In addition to its
use for narcolepsy, Provigil is also approved for the treatment of shift work sleep disorder, or SWSD, and
sleep apnea. Known side effects experienced by patients taking Modafinil include anxiety, depression, rash,
and rare occurrences of serious and potentially life threatening reactions including Stevens Johnson Syndrome,
Toxic Epidermal Necrolysis, and multi-organ hypersensitivity. Sales of Provigil in 2006 were reported to be
over $700 million. Although Provigil appears to be an improvement over previous narcolepsy drugs, certain
safety concerns were raised by the FDA when Cephalon, Inc. attempted to gain approval of modafinil for
ADHD, and the company subsequently abandoned efforts in this market.

Similarly, individuals with attention or cognitive disorders may suffer from an inability to focus, solve

problems, process information, communicate, and may have memory impairment. Attention and cognitive
disorders include ADHD, Alzheimer’s disease and other forms of dementia. Datamonitor estimates that
23 million children in the seven major pharmaceutical markets (United States, France, Germany, Italy, Spain,
United Kingdom and Japan) that suffer from ADHD. Research also shows that 60% of children with ADHD
maintain the disorder into adulthood. Despite the low rate of diagnosis, ADHD drug revenues reached

7

$2.5 billion in 2004, 97% of which was generated within the United States. Currently available treatments
cause side effects and do not adequately address the clinical need. Ritalin» (methylphenidate) is the most
widely prescribed ADHD therapy. As a stimulant with abuse potential, it has been classified as a controlled
substance by the FDA and the U.S. Drug Enforcement Agency. We believe there exists a significant market
opportunity for safer and more effective treatments.

We are developing multiple classes of highly selective and potent compounds designed to block the
H3 receptor and have established a program to develop non-stimulant, non-addictive, orally administered drugs
for the treatment of narcolepsy or other conditions related to excessive daytime sleepiness. Our histamine
H3 receptor antagonists represent a new class of drugs that could have an improved efficacy and safety profile
relative to existing drugs used for the treatment of narcolepsy and related sleep disorders. The H3 receptor
regulates levels of histamine and other neurotransmitters in certain areas of the brain that play a direct role in
regulating sleep and cognitive function. In animal models, H3 receptor antagonists have been shown to
increase histamine release in the brain and improve wakefulness, attention and learning. In a preclinical study
recently conducted at an independent lab, we have tested one of our more advanced compounds in a well
validated rodent sleep model. During the study, this compound significantly enhanced wakefulness without
causing apparent adverse events. In comparison to modafinil or caffeine, this compound was far more potent,
achieving a comparable or better effect on wakefulness at substantially lower doses. In addition, this compound
did not appear to cause the excessive rebound sleepiness that is a characteristic of other agents used to
promote wakefulness, such as amphetamines.

We intend to continue the study of this and other H3 antagonist compounds we are developing for
potential applications in treating narcolepsy, excessive daytime sleepiness, certain attention or cognitive
disorders, and other conditions. In addition, we intend to conduct additional pharmacology and safety testing.
If these studies are successful, and depending on the availability of capital resources, we would consider filing
an IND for the initiation of clinical trials. Recently, pharmaceutical companies such as Glaxo-SmithKline and
Johnson & Johnson have advanced H3 antagonists into clinical trials for the treatment of conditions such as
narcolepsy and dementia, respectively.

Regenerative Medicine Programs

MultiStem — A Novel Approach to Regenerative Medicine

In addition to our pharmaceutical programs, we are developing a proprietary nonembryonic stem cell

product candidate, MultiStem, that we believe has potential utility for treating a broad range of diseases and
could have widespread application in the field of clinical regenerative medicine such as in the treatment of
heart attack, the side effects associated with HSC/bone marrow transplantation for certain hematopoietic
malignancies such as graft versus host disease, or GVHD, stroke, and potentially other areas. We have received
FDA authorization to initiate clinical trials in the areas of AMI and HSC transplant support. We believe that
MultiStem represents a significant advancement in the field of stem cell therapy.

The therapeutic benefit of bone marrow transplantation has been recognized for decades, and its clinical

use has grown since Congress passed the National Organ Transplant Act in 1984, and the National Marrow
Donor Registry was established in 1990. However, for several reasons, widespread bone marrow or stem cell
transplantation has yet to become a reality. Some of the limitations that have prevented broader clinical
application of bone marrow or stem cell transplantation include the requirement for tissue matching between
donor and recipient, the inability to efficiently produce significant quantities of stem cells, and a range of
potential safety issues. While the field of stem cell therapy is very promising, it is also highly controversial
and fraught with challenges.

A stem cell therapy that has the potential to address the challenges mentioned above could represent a

breakthrough in the field of regenerative medicine, since it could greatly expand the clinical areas that utilize
stem cell therapy or other forms of regenerative medicine. In 2002, Dr. Catherine Verfaillie and her team
published research first describing a rare and novel stem cell, the Multipotent Adult Progenitor Cell, or
MAPC, which may be isolated from adult bone marrow as well as other nonembryonic tissues. In their

8

potential product form, we refer to these cells as MultiStem. These cells exhibit several important biological
properties, including:

(cid:129) Broad plasticity and multiple potential mechanisms of action. MultiStem cells have a demonstrated

ability in animal models to form multiple cell types and appear to be able to deliver therapeutic benefit
through multiple mechanisms, such as producing factors that protect tissues against damage and
inflammation, as well as enhancing or playing a direct role in revascularization or tissue regeneration.

(cid:129) Large scale production. Unlike conventional stem cells, such as blood-forming or hematopoietic stem
cells, MultiStem cells may be produced on a large scale, processed, and cryogenically preserved, and
then used clinically in a rapid and efficient manner. Material obtained from a single donor may be used
to produce hundreds of thousands or more of individual doses.

(cid:129) “Off-the-shelf” utility. Unlike traditional bone marrow or hematopoietic stem cell transplants, which
require extensive genetic matching between donor and recipient, MultiStem cells do not appear, based
on preclinical testing in animals, to require extensive tissue matching prior to administration. MultiStem
treatment may be allogeneic, meaning that these cells would not need to be genetically matched
between donor and recipient. This feature, combined with the ability to establish large MultiStem
banks, could make it practical for clinicians to efficiently deliver stem cell therapy to a large number of
patients.

(cid:129) Safety. Other stem cell types, such as embryonic stem cells, can pose serious safety risks, such as the
formation of tumors or ectopic tissue. In contrast, MultiStem cells have an outstanding safety profile
that has been compiled over several years of preclinical study in a range of animal models by a variety
of investigators.

At each step of the MultiStem production process, cells are analyzed and qualified according to pre-
established criteria to ensure that a consistent, well characterized product candidate is produced. Cells are
harvested from a pre-qualified donor and then expanded to form a Master Cell Bank from which we produce
clinical grade material. In March 2007, we and our manufacturing partner, Lonza, announced the successful
establishment of a Master Cell Bank produced under Good Manufacturing Practices, or GMP, and the
production of clinical grade material for our initial clinical trials. We have studied MultiStem in animal models
of radiation therapy and GVHD. In multiple animal models, MultiStem has been shown to be non-
immunogenic, even when administered without the genetic matching that is typically required for conventional
bone marrow or stem cell transplantation.

MultiStem allows us to pursue multiple high value commercial opportunities from a single product
platform, since we believe it has potential application in a range of disease states and therapeutic areas. For
example, based on numerous preclinical discussions with the FDA, we believe that we will be able to reuse, in
regulatory filings, data and information from certain preclinical safety studies to support the development of
MultiStem for treating multiple distinct diseases. As a result, we expect to be able to efficiently add additional
clinical indications as we further expand the scope of potential applications for MultiStem, enabling us to
reduce costs and shorten development timelines in comparison to traditional single-use preclinical studies.

MultiStem for Heart Attack, HSC Transplant Support in Treatment of Hematologic Malignancies & Stroke

Working with independent investigators at a number of leading institutions, such as the University of

Minnesota, the Cleveland Clinic, the National Institutes of Health, the Medical College of Georgia, and the
University of Oregon Health Sciences Center, we have studied MultiStem in a range of animal models that
reflect various types of human disease or injury, such as myocardial infarction, stroke, brain damage due to
restricted blood flow in newborns, vascular disease, and bone marrow transplant support/GVHD. In addition,
we are exploring, or intend to explore, the potential application of MultiStem in the treatment of a range of
other conditions such as certain blood or immune deficiencies and various autoimmune diseases.

As stated above, we have consistently observed that MultiStem is safe and effective in animal models. As
a result, we initially plan, subject to the availability of adequate resources, to advance MultiStem into clinical
development in three areas: treatment of damage caused by myocardial infarction; support in the hematologic

9

malignancy setting to reduce certain complications associated with HSC transplantation; and treatment for
stroke caused by a blockage of blood flow in the brain. For these areas, we intend to use one MultiStem cell
product, produced and validated using a single manufacturing platform.

Heart Attack

We are exploring the use of MultiStem as a treatment for damage caused by myocardial infarction, or
heart attack. Myocardial infarction is one of the leading causes of death and disability in the United States.
Myocardial infarction is caused by the blockage of one or more arteries that supply blood to the heart. Such
blockages can be caused, for example, by the rupture of an atherosclerotic plaque deposit. According to the
American Heart Association 2007 Statistical Update, there were approximately 865,000 cases of myocardial
infarction that occurred in the United States in 2004 and approximately 7.9 million individuals living in the
United States that had previously suffered a heart attack. In addition, there were more than 452,000 deaths that
occurred from various forms of ischemic heart disease, and 156,000 deaths due directly to myocardial
infarction in 2004. A variety of risk factors are associated with an elevated risk of myocardial infarction or
atherosclerosis, including age, high blood pressure, smoking, sedentary lifestyle and genetics. While advances
in the diagnosis, prevention and treatment of heart disease have had a positive impact, there is clearly room
for improvement — myocardial infarction remains a leading cause of death and disability in the United States
and the rest of the world.

MultiStem has been studied in validated animal models of AMI at both the Cleveland Clinic and the
University of Minnesota. Investigators demonstrated that the administration of allogeneic MultiStem into the
hearts of animals damaged by experimentally induced heart attacks resulted in significant functional improve-
ment in cardiac output and other functional parameters compared with animals that received placebo or no
treatment. Furthermore, the administration of immunosuppressive drug was not required and provided no
additional benefit in this study, and supports the concept of potentially using MultiStem as an allogeneic
product.

Working with a qualified contract research organization, we completed additional preclinical studies in
established pig models of acute myocardial infarction using catheter delivery and examining various factors
such as the route and method of MultiStem administration, dose ranging, and timing of treatment. Upon
obtaining the results of these and other studies, we filed an IND for the use of MultiStem for the treatment of
acute myocardial infarction, and in December 2007, we announced the authorization by the FDA of our IND
for this indication. We intend to initiate a multicenter Phase I clinical trial in this indication in 2008. We
intend to work with leading experts in the area of cardiovascular disease to complete the Phase I clinical trial.

We are developing MultiStem for this indication in conjunction with our partner, Angiotech. We entered

into a product co-development collaboration with Angiotech in May 2006, for the potential application of
MultiStem in multiple cardiovascular indications including myocardial infarction, peripheral vascular disease
and certain other indications.

HSC Transplant Support in Hematologic Malignancy

Another area of focus of our regenerative medicine program is the use of MultiStem as adjunctive
treatment for HSC/bone marrow transplant used as therapy in hematologic malignancy. For many types of
cancer, such as leukemia or other blood-borne cancers, treatment typically involves radiation therapy or
chemotherapy, alone or in combination. Such treatment can substantially deplete the cells of the blood and
immune system, by reducing the number of stem cells in the bone marrow from which they arise. The more
intense the radiation treatment or chemotherapy, the more severe the resulting depletion of the bone marrow,
blood, and immune system. However, other tissues may also be affected, such as cells in the digestive tract
and in the pulmonary system. The result may be severe anemia, immunodeficiency, significant reduction in
digestive capacity, and other problems, which may result in significant disability or death.

One strategy for treating the depletion of bone marrow is to perform a peripheral blood stem cell
transplant or a bone marrow transplant. This approach may augment the patient’s ability to form new blood
and immune cells and provide a significant survival advantage. However, finding a closely matched donor is

10

frequently difficult or even impossible. Even when such a donor is found, in many cases there are
immunological complications, such as GVHD, which may result in death or serious disability.

Working with leading experts in the stem cell and bone marrow transplantation field, we have studied
MultiStem in animal models of radiation therapy and GVHD. In multiple animal models, MultiStem has been
shown to be non-immunogenic, even when administered without the genetic matching that is typically required
for conventional bone marrow or stem cell transplantation. Furthermore, in animal model systems testing
immune reactivity of T-cells against unrelated donor tissue, MultiStem has been shown to suppress the T-cell-
mediated immune responses that are an important factor in causing GVHD. MultiStem-treated animals also
displayed a significant increase in survival relative to controls. As a result, we believe that the administration
of MultiStem in conjunction with or following standard HSC transplantation may have the potential to reduce
the incidence or severity of complications and may enhance other important functions.

In November 2007, we announced authorization by the FDA of our IND for the application of MultiStem

in support of bone marrow transplantation for the treatment of certain cancers of the blood and immune
system. We intend to initiate a Phase I clinical trial in 2008 examining the safety and tolerability of MultiStem
in patients receiving a bone marrow transplant related to their treatment for hematologic malignancy. The trial
will be an open label, multicenter trial. Participating clinicians will include leading experts in the field of bone
marrow transplantation.

Stroke

A third focus of our regenerative medicine program is the use of MultiStem for the treatment of

neurological injury as a result of ischemic stroke, which accounts for approximately 80% of all strokes. Recent
progress toward the development of safer and more effective treatments for ischemic stroke has been
disappointing. Despite the fact that stroke is one of the leading causes of death and disability in the
United States, affecting more than 700,000 new patients annually according to the CDC, there has been little
progress toward the development of treatments that improve the prognosis for stroke victims. The only FDA-
approved drug currently available for ischemic stroke is the anti-clotting factor, tPA, which must be
administered to the patient within roughly three hours of the onset of the stroke. Administration of tPA after
this time frame is not recommended, since it can cause bleeding or even death. Given this limited therapeutic
window, it is estimated that less than 5% of ischemic stroke victims currently receive treatment with tPA.

In preclinical studies conducted by investigators at both the University of Minnesota and the Medical
College of Georgia, significant functional improvements have been observed in rodents that have undergone an
experimentally induced stroke, or that have incurred significant neurological damage as a result of neonatal
hypoxic ischemia, and then received treatment with MultiStem. Through research conducted by collaborators
at the Medical College of Georgia and presented at the annual American Academy of Neurology meeting in
April 2006, we observed that administration of MultiStem even one week after a surgically induced stroke
results in substantial long-term therapeutic benefit, as evidenced by the improvement of treated animals
compared with controls in a battery of tests examining mobility, strength, fine motor skills, and other aspects
of neurological functional improvement. These results have been confirmed in subsequent studies that
demonstrate MultiStem treatment is well tolerated, does not require immunosuppression, and results in a
robust and durable therapeutic benefit even when administered one week after the initial stroke event.

Upon completion of remaining preclinical safety studies, we intend to submit an IND for this application
in 2008. The subsequent initiation of a clinical trial will depend on obtaining FDA authorization of this IND,
and the availability of capital resources to complete the study.

We believe that MultiStem could have broad potential to treat a range of conditions. In addition to the

above programs, we are collaborating or intend to collaborate with other highly qualified investigators to
evaluate the potential benefits of MultiStem in other disease indications, such as various blood and immune
deficiencies, certain autoimmune diseases and other potential indications.

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Other Key Technologies

In addition to our product development programs, we have developed RAGE, a patented technology that
provides us with the ability to produce human cell lines that express specific, biologically well validated drug
targets without relying upon cloned and isolated gene sequences. This technology platform provides us with
broad freedom to work with drug targets that may be inaccessible to most other companies as a result of
intellectual property restrictions on the use of specific cloned and isolated genes. Over the past several years,
we have produced cell lines that express drug targets in a range of disease areas such as metabolic disease,
infectious disease, oncology, cardiovascular disease, inflammation and central nervous system disorders. Many
of these were produced for drug development programs at major pharmaceutical companies that we have
collaborated with, and some have been produced for our internal drug development programs.

Collaborations and Partnerships

Angiotech

In May 2006, we established a collaboration with Angiotech that is focused on co-developing MultiStem
for the treatment of damage caused by myocardial infarction and peripheral vascular disease. In support of the
collaboration, Angiotech purchased $10.0 million in aggregate principal amount of subordinated convertible
promissory notes, the principal amount of which was automatically converted along with accrued interest into
our common stock upon the closing of our financing in June 2007. We may also receive up to $3.75 million
of additional equity investments and $63.75 million of aggregate cash payments based upon the successful
achievement of specified clinical development and commercialization milestones, though there can be no
assurance that we will achieve any milestones.

Under the terms of the collaboration, the parties plan to jointly fund clinical development activity,

whereby preclinical costs will be borne solely by Athersys, costs for phase I and phase II studies will be borne
50% by Athersys and 50% by Angiotech, costs for the first phase III study will be borne 33% by Athersys and
67% by Angiotech, and costs for any phase III studies subsequent to the first phase III study will be borne
25% by Athersys and 75% by Angiotech. We will have lead responsibility for preclinical and early clinical
development and manufacturing of the MultiStem product, and Angiotech will take the lead on pivotal and
later clinical trials and commercialization. We will receive nearly half of the net profits from the sale of any
jointly developed, approved products. In addition, we will retain the commercial rights to MultiStem for all
other therapeutic applications, including treatment of stroke, bone marrow transplantation and oncology
support, blood and immune system disorders, autoimmune disease, and other indications that we may elect to
pursue.

In December 2007, we achieved a clinical development milestone upon the authorization of our IND by

the FDA. This milestone event required Angiotech to either purchase $5.0 million of our common stock or
forego the purchase and allow us to select from two pre-defined milestone replacements. Angiotech opted to
forego the purchase, and we elected to increase our share of the net profits from the future sale of approved
products as the replacement milestone.

The Angiotech collaboration does not have a specific termination date, but will terminate upon the

earliest to occur of:

(cid:129) if at least one cell therapy product has obtained regulatory approval and we and Angiotech have shared
profits with respect to sales of at least one cell therapy product, the date that there has been no sales
for 12 months of any cell therapy product that has been the subject of profit-sharing, unless a clinical
development candidate is in at least a Phase III clinical or later; and

(cid:129) the later of (1) the expiration date of the last-to-expire patent licensed to Angiotech, which is expected

to be August 5, 2019 based on currently issued patents, and (2) the 15-year anniversary.

Neither we nor Angiotech may terminate the collaboration at will; however, either party may elect at
certain points to not move forward with individual product development programs. If either party breaches its
material obligations and fails to cure that breach within 60 days after notice from the non-breaching party, the

12

non-breaching party may terminate the collaboration. Angiotech has a right to immediately terminate the
collaboration upon certain bankruptcy events involving us. Angiotech also has the right to terminate the
collaboration upon 120 days’ prior notice if Angiotech, in its reasonable judgment, determines that: (1) a
primary endpoint in a clinical study within a clinical development plan has not been met; (2) the clinical
efficacy and/or safety with respect to a clinical development candidate or a cell therapy product have not been
demonstrated; (3) applicable regulatory requirements for cells, a clinical development candidate or a cell
therapy product in one or more major markets shall have a material adverse impact on the ability to obtain
regulatory approval for a cell therapy product in such markets; (4) our data regarding cells, a clinical
development candidate or a cell therapy product were obtained, in whole or in part, through scientific fraud; or
(5) a cell therapy product is not (or is not expected to be) commercially viable or profitable in at least one
major market.

Bristol-Myers Squibb

In December 2000, we entered into a collaboration with Bristol-Myers Squibb to provide cell lines

expressing well validated drug targets produced using our RAGE technology for compound screening and
development. This initial collaboration was expanded in 2002 and again in 2006. Bristol-Myers Squibb uses
the cell lines in its internal drug development programs and, in exchange, we receive license fee and milestone
payments and will be entitled to receive royalties on the sale of any approved products. Depending on the use
of a cell line by Bristol-Myers Squibb and the progress of drug development programs benefiting from the use
of such a cell line, we may receive as much as approximately $5.5 million per cell line in additional license
fees and milestone payments, though we cannot assure you that we will achieve any milestones or receive any
payments. Through December 31, 2007, we have received an aggregate of approximately $6.0 million in
license fees and milestone payments from Bristol-Myers Squibb.

The Bristol-Myers Squibb collaboration does not have a specific termination date, but will terminate

when Bristol-Myers Squibb no longer has an obligation to pay us royalties, which obligation generally
continues until the later of the expiration of the Bristol-Myers Squibb patent covering an approved product and
ten years after commercial sales of that product began. Though we expect Bristol-Myers Squibb to file for and
be issued patents for products developed under the collaboration, we are not aware of any patents issued to
Bristol-Myers Squibb covering any potential products related to the collaboration. If either party breaches its
material obligations and fails to cure that breach within 60 days after notice from the non-breaching party, the
non-breaching party may terminate the collaboration.

Competition

We face significant competition with respect to the various dimensions of our business. With regards to

our efforts to develop ATHX-105 or other compounds for the treatment of obesity, there are already approved
therapeutic products on the market, such as Xenical, which is marketed by Roche, and Meridia, which is
marketed by Abbott Pharmaceuticals. However, both of these drugs can have side effects that we believe have
limited their adoption by patients and clinicians. For example, potential side effects associated with taking
Xenical include cramping, intestinal discomfort, flatulence, diarrhea, and leakage of oily stool. Potential side
effects associated with taking Meridia include increased blood pressure and heart rate, headache, dry mouth,
constipation, and insomnia. Individuals with high blood pressure, heart disease, irregular heart beat, or a
history of stroke are cautioned not to take Meridia.

In addition to these products, other companies are actively developing therapeutic products for the
treatment of obesity, including Sanofi-Aventis, which is developing the drug Rimonabant, which acts by
suppressing appetite by blocking the CB1 receptor, also known as the marijuana receptor for its recognized
role as the site of action of the cannabinoids found in marijuana that can stimulate appetite. Rimonabant has
been approved for use in Europe in treating obesity, but is not approved for use in the United States. In
Phase III clinical trials, patients taking Rimonabant exhibited statistically significant weight loss. Notable
adverse events among some patients taking the drug included respiratory infection, dizziness, nausea, anxiety,
and depression, which were observed at higher frequency among patients taking the drug relative to those
taking placebo in the control group. In June 2007, an FDA advisory panel voted unanimously against the

13

approval of Rimonabant, citing safety concerns potentially associated with this drug class and its biological
mechanism of action, and Sanofi withdrew its NDA application shortly thereafter. However, Rimonabant is
still approved for use in Europe. Other pharmaceutical companies including Merck and Pfizer are also
developing CB1 antagonists.

Other companies are also attempting to develop novel 5HT2c agonists. One company, Arena Pharmaceu-

ticals, completed a Phase II clinical trial with its novel product candidate APD356, also referred to as
Lorcaserin. Clinically obese patients taking 10 mg of the drug twice per day exhibited statistically significant
weight loss over the three-month study period, exhibiting an average loss of 7.9 lbs, compared to those taking
the placebo, who lost an average of 0.7 lbs. All patients on the study underwent cardiovascular safety
monitoring both during and after the study, and there were no reported adverse events with respect to
cardiovascular safety according to the company. Potential side effects observed among patients taking the drug
at 10 mg dose twice per day included headache (26.7% vs. 17.8% in the placebo group), dizziness (7.8% vs.
0% in the placebo group), nausea (11.2% vs. 3.4% in the placebo group), and vomiting (5.2% vs. 0.8% in the
placebo group).

In February 2007, Arena Pharmaceuticals announced that it had completed enrollment of 3,182 patients

in a double blind, randomized and placebo controlled Phase III clinical trial of Lorcaserin designed to evaluate
safety and efficacy of twice daily 10 mg doses of Lorcaserin administered for one year. The primary efficacy
endpoint is the percentage of patients exhibiting greater than 5% weight loss over baseline at 52 weeks. An
independent Data Safety Monitoring Board will evaluate cardiovascular safety in all patients at 6 and
12 months after initiation of the trial. The results of the initial six-month review were announced in the third
quarter of 2007 and indicated no significant cardiovascular safety issues. The results of the twelve-month
cardiovascular safety review are expected in the first quarter of 2008. Arena Pharmaceuticals has initiated two
additional Phase III clinical trials of Lorcaserin to further evaluate the drug, including in the Type 2 diabetes
population.

There are many other companies attempting to develop novel treatments for obesity, and a wide range of
approaches are being taken. Some of these companies include large, multinational pharmaceutical companies
such as Pfizer, Bristol-Myers Squibb, Merck, Roche, Sanofi-Aventis, GlaxoSmithKline, Eli Lilly and others.
There are also a variety of biotechnology companies developing treatments for obesity, including Orexigen,
Vivus, Neurosearch, Amgen, Regeneron, Nastech Pharmaceutical Company, Alizyme, Amylin Pharmaceuticals,
Neurocrine Biosciences, Shionogi, Metabolic Pharmaceuticals, Kyorin Pharmaceutical, and others. It is likely
that, given the magnitude of the market opportunity, many companies will continue to focus on the obesity
area, and that competition will remain high. If we are successful at developing ATHX-105 or another
compound as a safe and effective treatment for obesity, it is likely that other companies will attempt to
develop safer and more effective 5HT2c agonists, or will attempt to combine therapies in an effort to establish
a safer and more effective therapeutic product.

We also face significant competition with respect to our efforts to develop MultiStem as a novel stem cell

therapy. Currently, there are a number of companies that are actively developing stem cell products, which
encompass a range of different cell types, including embryonic stem cells, umbilical cord stem cells, adult-
derived stem cells, and processed bone marrow derived cells. These include both public companies, such as
Osiris, Genzyme, Geron, Aastrom Biosciences, Stem Cells Inc., Cell Genesys, Viacell, Celgene, Advanced
Cell Technology, CRYO-CELL International, Mesoblast Limited and Cytori Therapeutics, and private compa-
nies, such as Cognate Therapeutics, Neuronyx, Gamida Cell, Arteriocyte, Plureon and others. Given the
magnitude of the potential opportunity for stem cell therapy, we expect competition in this area to intensify in
the coming years.

Finally, we face competition with respect to our ability to produce drug targets for our drug development
programs. There are many companies with established intellectual property that seek to restrict or protect the
use of specific drug targets, including Incyte, Millennium Pharmaceuticals, Human Genome Sciences, Lexicon
Genetics, CuraGen, Exelixis, Myriad Genetics, Sangamo BioSciences, and others.

We believe our most significant competitors are fully integrated pharmaceutical companies and more
established biotechnology companies that have substantially greater financial, technical, sales, marketing, and

14

human resources than we do. These companies may succeed in obtaining regulatory approval for competitive
products more rapidly than we can for our products. In addition, our competitors may develop technologies
and products that are cheaper, safer or more effective than those being developed by us or that would render
our technology obsolete. Furthermore, some of these companies may feel threatened by our activities, and
attempt to delay or impede our efforts to develop our products, or apply our technologies.

Intellectual Property

We rely on a combination of patent applications, patents, trademarks, and contractual provisions to protect

our proprietary rights. We believe that to have a competitive advantage, we must develop and maintain the
proprietary aspects of our technologies. Currently, we require our officers, employees, consultants, contractors,
manufacturers, outside scientific collaborators and sponsored researchers, and other advisors to execute
confidentiality agreements in connection with their employment, consulting, or advisory relationships with us,
where appropriate. We also require our employees, consultants, and advisors who we expect to work on our
products to agree to disclose and assign to us all inventions conceived during the work day, developed using
our property, or which relate to our business.

We have established a broad intellectual property portfolio related to our key functional genomics
technologies and product candidates. We have a broad patent estate with claims directed to compositions,
methods of making, and methods of using our small molecule drug candidates. In our 5HT2c program, we
have filed four patent applications with broad claims directed to ATHX-105, related compounds in the same
chemical series from which ATHX-105 was derived, and back-up and second generation compounds from
distinct chemical series. In our Histamine H3 program, we have filed four patent applications with broad
claims directed to compounds from two distinct chemical series. All compounds described in these patent
applications were discovered at Athersys. In addition, we currently have twelve issued U.S. patents and various
issued international patents relating to compositions and methods for the RAGE technology. These patents will
expire in 2017. There are also several patent applications relating to human proteins and candidate drug targets
that we have identified through the application of RAGE and our other technologies. The RAGE technology
was developed by Dr. John Harrington and other Athersys scientists internally in the mid-1990s.

We have a broad patent estate with claims directed to compositions, methods of production, and methods

of use of MAPCs and related technologies. We acquired ownership of part of our stem cell technology and
intellectual property as a result of our 2003 acquisition of a holding company, which held the rights to the
technology originally discovered at the University of Minnesota. We have one issued U.S. patent related to
this technology, and three U.S. patent applications, as well as many corresponding international patent
applications. In addition, there are six pending applications for additional MAPC-related inventions from
research conducted by us alone or with our collaborators.

We also have an exclusive license to additional MAPC-related inventions (or in other words, improve-

ments) developed by the University of Minnesota, which includes 13 pending patent applications, and covers
inventions made at the University of Minnesota through May 2009. We pay all patent prosecution costs for the
inventions that we elect to license. This license agreement terminates when the last patent licensed to us
expires (currently, no U.S. patents have been granted for inventions subject to the license agreement). We may
terminate the license agreement at any time. The University of Minnesota may terminate the license if we fail
to pay royalties when due or fail to perform the material terms of the license, such as our obligation to use
commercially reasonable efforts to commercialize the MAPC technology. The University of Minnesota is
entitled to a royalty on net sales of products developed from the MAPC technology.

In addition, under a collaborative research agreement with the Katholieke Universiteit Leuven (KUL), we

have an exclusive license to MAPC-related inventions, which include one pending application developed at
KUL using the MAPC technology or intellectual property or that result from sponsored research funded by us.
KUL is entitled to milestone payments related to the continued operation of the research agreement and would
receive a royalty on net sales of products developed using MAPC-related inventions. The research agreement
may be terminated after two years or upon material breach by either party. KUL may terminate the license if
we fail to pay royalties when due or upon material breach of the license terms.

15

We believe that we have broad freedom to use and commercially develop our technologies and product
candidates. However, if successful, a patent infringement suit brought against us may force us or any of our
collaborators or licensees to stop or delay developing, manufacturing, or selling potential products that are
claimed to infringe a third party’s intellectual property, unless that party grants us rights to use its intellectual
property. In such cases, we may be required to obtain licenses to patents or proprietary rights of others to
continue to commercialize our products. However, we may not be able to obtain any licenses required under
any patents or proprietary rights of third parties on acceptable terms, or at all. Even if we were able to obtain
rights to the third party’s intellectual property, these rights may be non-exclusive, thereby giving our
competitors access to the same intellectual property. Ultimately, we may be unable to commercialize some of
our potential products or may have to cease some of our business operations as a result of patent infringement
claims, which could severely harm our business.

Research and Development

Our research and development costs, which consist primarily of costs associated with external clinical and

preclinical study fees, manufacturing costs, salaries and related personnel costs, legal expenses resulting from
intellectual property application processes, and laboratory supply and reagent costs, were $15.8 million in
2007, $9.7 million in 2006 and $12.6 million in 2005.

Government Regulation

Any products we may develop and our research and development activities are subject to stringent
government regulation in the United States by the FDA and, in many instances, by corresponding foreign and
state regulatory agencies. The European Union, or EU, has vested centralized authority in the European
Medicines Evaluation Agency and Committee on Proprietary Medicinal Products to standardize review and
approval across EU member nations.

These regulatory agencies enforce comprehensive statutes, regulations, and guidelines governing the drug
development process. This process involves several steps. Initially, the company must generate preclinical data
to show safety before human testing may be initiated. In the United States, the drug company must submit an
IND to the FDA prior to securing authorization for human testing. The IND must contain adequate data on
product candidate chemistry, toxicology and metabolism and, where appropriate, animal research testing to
support initial safety.

A CTA is the European equivalent of the U.S. IND. CTA requirements are issued by the Medicines and

Healthcare Products Regulatory Agency, the United Kingdom’s health authority and were enacted through the
U.K. Medicines for Human Use (Clinical Trials) Regulations 2004, which implemented the EU Clinical Trials
Directive in the United Kingdom.

Any of our product candidates will require regulatory approval and compliance with regulations made by
U.S. and foreign government agencies prior to commercialization in such countries. The process of obtaining
FDA or foreign regulatory agency approval has historically been extremely costly and time consuming. The
FDA regulates, among other things, the development, testing, manufacture, safety, efficacy, record keeping,
labeling, storage, approval, advertising, promotion, sale, and distribution of biologics and new drugs.

The standard process required by the FDA before a pharmaceutical agent may be marketed in the United

States includes:

(cid:129) preclinical tests in animals that demonstrate a reasonable likelihood of safety and effectiveness in

human patients;

(cid:129) submission to the FDA of an IND, which must become effective before clinical trials in humans can
commence. If Phase I clinical trials are to be conducted initially outside the United States, a different
regulatory filing is required, depending on the location of the study;

(cid:129) adequate and well controlled human clinical trials to establish the safety and efficacy of the drug or

biologic in the intended disease indication;

16

(cid:129) for drugs, submission of a New Drug Application, or NDA, or a Biologic License Application, or BLA,

with the FDA; and

(cid:129) FDA approval of the NDA or BLA before any commercial sale or shipment of the drug.

Preclinical studies can take several years to complete, and there is no guarantee that an IND based on
those studies will become effective to permit clinical trials to begin. Once clinical trials are initiated, they
generally take five to seven years, or longer, to complete. After completion of clinical trials of a new drug or
biologic product, FDA approval of the NDA or BLA must be obtained. This process requires substantial time
and effort and there is no assurance that the FDA will accept the NDA or BLA for filing and, even if filed,
that the FDA will grant approval. In the past, the FDA’s approval of an NDA or BLA has taken, on average,
one to two years, but in some instances may take substantially longer. If questions regarding safety or efficacy
arise, additional studies may be required, followed by a resubmission of the NDA or BLA. Review and
approval of an NDA or BLA can take up to several years.

In addition to obtaining FDA approval for each product, each drug manufacturing facility must be
inspected and approved by the FDA. All manufacturing establishments are subject to inspections by the FDA
and by other federal, state, and local agencies, and must comply with GMP requirements. We do not currently
have any GMP manufacturing capabilities, and will rely on contract manufacturers to produce ATHX-105 and
MultiStem for any clinical studies that we may conduct.

We must also obtain regulatory approval in other countries in which we intend to market any drug. The
requirements governing conduct of clinical trials, product licensing, pricing, and reimbursement vary widely
from country to country. FDA approval does not ensure regulatory approval in other countries. The current
approval process varies from country to country, and the time spent in gaining approval varies from that
required for FDA approval. In some countries, the sale price of the drug must also be approved. The pricing
review period often begins after market approval is granted. Even if a foreign regulatory authority approves a
drug product, it may not approve satisfactory prices for the product.

In addition to regulations enforced by the FDA, we are also subject to regulation under the Occupational

Safety and Health Act, the Environmental Protection Act, the Toxic Substances Control Act, the Resource
Conservation and Recovery Act, and other present and potential future federal, state, or local regulations. Our
research and development involves the controlled use of hazardous materials, chemicals, biological materials,
and various radioactive compounds. Although we believe that our safety procedures for handling and disposing
of such materials currently comply in all material respects with the standards prescribed by state and federal
regulations, the risk of accidental contamination or injury from these materials cannot be completely
eliminated. In the event of such an accident, we could be held liable for any damages that result and any such
liability could exceed our available resources.

Employees

We believe that our success will be based on, among other things, the quality of our science, our ability
to invent and develop superior and innovative technologies and products, and our ability to attract and retain
capable management and other personnel. We have assembled a high quality team of scientists and executives
with significant experience in the biotechnology and pharmaceutical industries.

As of December 31, 2007, we employed 31 individuals, of whom 14 hold Ph.D. degrees. In addition to
our employees, we also use the service and support of several outside consultants and advisors. None of our
employees is represented by a union, and we believe relationships with our employees are good.

Available Information

Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and all
amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange
Act of 1934 are available free of charge on our website, www.athersys.com, as soon as reasonably practicable
after they are filed with, or furnished to, the SEC.

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Merger and Name Change

On June 8, 2007, Athersys, Inc., a Delaware corporation, merged with a wholly owned subsidiary of

BTHC VI, Inc., a Delaware corporation. On August 31, 2007, Athersys, Inc. changed its name to ABT
Holding Company, and BTHC VI, Inc. changed its name to Athersys, Inc. In this annual report, unless
otherwise indicated or the context otherwise requires, all references to “we” or “us” are to Athersys, Inc., the
Delaware corporation formerly known as BTHC VI, Inc., together with its wholly owned subsidiary, ABT
Holding Company, the Delaware corporation formerly known as Athersys, Inc. Specific discussions or
comments relating only to BTHC VI, Inc. prior to the merger described above reference “BTHC VI,” while
those relating only to our subsidiary Athersys, Inc. prior to the merger reference “Athersys.”

ITEM 1A. RISK FACTORS

The statements in this section, as well as statements described elsewhere in this annual report, or in other

SEC filings, describe risks that could materially and adversely affect our business, financial condition and
results of operations and the trading price of our equity securities could decline. These risks are not the only
risks that we face. Our business, financial condition and results of operations could also be affected by
additional factors that are not presently known to us or that we currently consider to be immaterial to our
operations.

Risks Related To Our Business and Our Industry

Athersys has incurred losses since inception and we expect to incur significant net losses in the
foreseeable future and may never become profitable.

Since Athersys’ inception in 1995, it has incurred significant losses and negative cash flows from

operations. Athersys has incurred net losses of $14.6 million in 2005, $10.6 million in 2006 and $18.9 million
in 2007. As of December 31, 2007, we had an accumulated deficit of $160.5 million, and anticipate incurring
additional losses for at least the next several years. We expect to spend significant resources over the next
several years to enhance our technologies and to fund research and development of our pipeline of potential
products. To date, substantially all of Athersys’ revenue has been derived from corporate collaborations,
license agreements, and government grants. In order to achieve profitability, we must develop products and
technologies that can be commercialized by us or through future collaborations. Our ability to generate
revenues and become profitable will depend on our ability, alone or with potential collaborators, to timely,
efficiently and successfully complete the development of our product candidates. We have never earned
revenue from selling a product and we may never do so, as none of our product candidates have been tested
yet in humans. We cannot assure you that we will ever earn revenue or that we will ever become profitable. If
we sustain losses over an extended period of time, we may be unable to continue our business.

We will need substantial additional funding to develop our products and for our future operations. If we
are unable to obtain the funds necessary to do so, we may be required to delay, scale back or eliminate
our product development or may be unable to continue our business.

The development of our product candidates will require a commitment of substantial funds to conduct the

costly and time-consuming research, which may include preclinical and clinical testing, necessary to obtain
regulatory approvals and bring our products to market. Net cash used in Athersys’ operations was $12.1 million
in 2005, $8.4 million in 2006 and $12.1 million in 2007. We anticipate using $23 million to $25 million to
fund our activities in 2008, which is an increase in cash expenditures reflecting the impact of the ATHX-105
Phase II clinical trial. With the anticipated completion of the ATHX-105 Phase II clinical trial, we expect
lower clinical development costs in 2009, and as a result, expect to have available cash to fund our operations
into 2010 based on our current business and operating plans and assuming no new financings. Our future
capital requirements will depend on many factors, including:

(cid:129) the progress and costs of our research and development programs, including our ability to develop our

current portfolio of therapeutic products, or discover and develop new ones;

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(cid:129) our ability, or our partners ability and willingness, to advance partnered products or programs;

(cid:129) the cost of prosecuting, defending and enforcing patent claims and other intellectual property rights;

(cid:129) the progress, scope, costs, and results of our preclinical and clinical testing of any current or future

pharmaceutical or MultiStem related products;

(cid:129) the time and cost involved in obtaining regulatory approvals;

(cid:129) the cost of manufacturing our product candidates;

(cid:129) expenses related to complying with GMP of therapeutic product candidates;

(cid:129) costs of financing the purchases of additional capital equipment and development technologies;

(cid:129) competing technological and market developments;

(cid:129) our ability to establish and maintain collaborative and other arrangements with third parties to assist in

bringing our products to market and the cost of such arrangements.

(cid:129) the amount and timing of payments or equity investments that we receive from collaborators or changes
in or terminations of future or existing collaboration and licensing arrangements and the timing and
amount of expenses we incur to supporting these collaborations and license agreements;

(cid:129) costs associated with the integration of any new operation, including costs relating to future mergers

and acquisitions with companies that have complementary capabilities;

(cid:129) expenses related to the establishment of sales and marketing capabilities for products awaiting approval

or products that have been approved;

(cid:129) the level of our sales and marketing expenses; and

(cid:129) our ability to introduce and sell new products.

We cannot assure you that we will not need additional capital sooner than currently anticipated. We will
need to raise substantial additional capital to fund our future operations. We cannot be certain that additional
financing will be available on acceptable terms, or at all. In recent years, it has been difficult for companies to
raise capital due to a variety of factors, which may or may not continue. To the extent we raise additional
capital through the sale of equity securities, the ownership position of our existing stockholders could be
substantially diluted. If additional funds are raised through the issuance of preferred stock or debt securities,
these securities are likely to have rights, preferences and privileges senior to our common stock. Fluctuating
interest rates could also increase the costs of any debt financing we may obtain.

Failure to successfully address ongoing liquidity requirements will have a material adverse effect on our
business. If we are unable to obtain additional capital on acceptable terms when needed, we may be required
to take actions that harm our business and our ability to achieve cash flow in the future, including possibly the
surrender of our rights to some technologies or product opportunities, delaying our clinical trials or curtailing
or ceasing operations.

We are heavily dependent on the successful development and commercialization of our two key product
candidates, ATHX-105 and MultiStem, and if we encounter delays or difficulties in the development of
either or both candidates, our business would be harmed.

We are developing multiple therapeutic product candidates, but we are heavily dependent upon the

successful development of two particular product candidates: ATHX-105 for the treatment of obesity and
MultiStem initially for the treatment of damage caused by certain cardiovascular disorders and for the
treatment of bone marrow transplant support and GVHD. Our business would be materially harmed if we
encounter difficulties in the development of either of these product candidates, such as:

(cid:129) delays in the ability to make either product in quantities or in a form that is suitable for any required

preclinical studies or clinical trials;

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(cid:129) delays in the design, enrollment, implementation or completion of required preclinical studies and

clinical trials;

(cid:129) an inability to follow our current development strategy for obtaining regulatory approval from the FDA

because of changes in the regulatory approval process;

(cid:129) less than desired or complete lack of efficacy or safety in preclinical studies or clinical trials; and

(cid:129) intellectual property constraints that prevent us from making, using, or commercializing either product

candidate.

The results seen in animal testing of our product candidates may not be replicated in humans.

This annual report discusses the safety and efficacy seen in preclinical testing of our lead product
candidates, including ATHX-105 and MultiStem, in animals, but we may not see positive results when
ATHX-105, MultiStem or any of our other product candidates undergo clinical testing in humans in the future.
Preclinical studies and Phase I clinical trials are not primarily designed to test the efficacy of a product
candidate in humans, but rather to:

(cid:129) test short-term safety and tolerability;

(cid:129) study the absorption, distribution, metabolism and elimination of the product candidate;

(cid:129) study the biochemical and physiological effects of the product candidate and the mechanisms of the

drug action and the relationship between drug concentration and effect; and

(cid:129) understand the product candidate’s side effects at various doses and schedules.

Success in preclinical studies or completed clinical trials does not ensure that later studies or trials,

including continuing non-clinical studies and large-scale clinical trials, will be successful nor does it
necessarily predict future results. The rate of failure in drug development is quite high, and many companies
in the biotechnology and pharmaceutical industries have suffered significant setbacks in advanced clinical
trials, even after promising results in earlier trials. Product candidates may fail to show desired safety and
efficacy in larger and more diverse patient populations in later stage clinical trials, despite having progressed
through early stage trials. Negative or inconclusive results from any of our ongoing preclinical studies or
clinical trials could result in delays, modifications, or abandonment of ongoing or future clinical trials and the
termination of our development of a product candidate. Additionally, even if we are able to successfully
complete pivotal Phase III clinical trials, the FDA still may not approve our product candidates.

Our products are in an early stage of development and we currently have no therapeutic products
approved for sale. If we are unable to develop, obtain regulatory approval or market any of our product
candidates, our financial condition will be negatively affected, and we may have to curtail or cease our
operations.

We are in the early stage of product development, and we are dependent on the application of our
technologies to discover or develop therapeutic product candidates. We currently do not sell any approved
therapeutic products and do not expect to have any products commercially available for several years, if at all.
You must evaluate us in light of the uncertainties and complexities affecting an early stage biotechnology
company. Our product candidates require additional research and development, preclinical testing, clinical
testing and regulatory review and/or approvals or clearances before marketing. To date, no one to our
knowledge has developed or commercialized any therapeutic products using our technologies and we might
never commercialize any product using our technologies and strategy.

In addition, we may not succeed in developing new product candidates as an alternative to our existing
portfolio of product candidates. If our current product candidates are delayed or fail, or we fail to successfully
develop and commercialize new product candidates, our financial condition may be negatively affected, and
we may have to curtail or cease our operations.

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We may not successfully maintain our existing collaborative and licensing arrangements, or establish new
ones, which could adversely affect our ability to develop and commercialize our product candidates.

A key element of our business strategy is to commercialize some of our product candidates through
collaborations with other companies. Our pharmaceutical strategy includes establishing collaborations and
licensing agreements with one or more pharmaceutical, biotechnology or device companies, preferably after
we have advanced product candidates through the initial stages of clinical development. However, we may not
be able to establish or maintain such licensing and collaboration arrangements necessary to develop and
commercialize our product candidates. Even if we are able to maintain or establish licensing or collaboration
arrangements, these arrangements may not be on favorable terms and may contain provisions that will restrict
our ability to develop, test and market our product candidates. Any failure to maintain or establish licensing or
collaboration arrangements on favorable terms could adversely affect our business prospects, financial
condition or ability to develop and commercialize our product candidates.

Our agreements with our collaborators and licensees may have provisions that give rise to disputes
regarding the rights and obligations of the parties. These and other possible disagreements could lead to
termination of the agreement or delays in collaborative research, development, supply, or commercialization of
certain product candidates, or could require or result in litigation or arbitration. Moreover, disagreements could
arise with our collaborators over rights to intellectual property or our rights to share in any of the future
revenues of products developed by our collaborators. These kinds of disagreements could result in costly and
time-consuming litigation. Any such conflicts with our collaborators could reduce our ability to obtain future
collaboration agreements and could have a negative impact on our relationship with existing collaborators.

Currently, our material collaborations and licensing arrangements are our product co-development
collaboration with Angiotech to jointly develop and ultimately market MultiStem for the treatment of damage
caused by myocardial infarction and peripheral vascular disease, our collaboration agreement with Bristol-
Myers Squibb pursuant to which we provide cell lines produced using our RAGE technology, and our license
with the University of Minnesota pursuant to which we license certain aspects of the MultiStem technology.
These arrangements do not have specific termination dates; rather, each arrangement terminates upon the
occurrence of certain events.

The Angiotech collaboration terminates upon the earliest to occur of (a) if at least one cell therapy
product has obtained regulatory approval and we and Angiotech have shared profits with respect to sales of at
least one cell therapy product, the date that there has been no sales for 12 months of any cell therapy product
that has been the subject of profit-sharing, unless a clinical development candidate is in at least a Phase III
clinical trial or later, or (b) the later of (1) the expiration date of the last-to-expire patent licensed to Angiotech
or (2) the 15-year anniversary. Neither we nor Angiotech may terminate the collaboration at will, but either
party may elect at certain points to not move forward with individual product development programs.
However, Angiotech has the right to terminate the collaboration if, among other things, Angiotech, in its
reasonable judgment, determines that a primary endpoint in a clinical study within a clinical development plan
has not been fulfilled or met, or if the clinical efficacy and/or safety with respect to cells, or a clinical
development candidate or a cell therapy product have not been demonstrated.

The Bristol-Myers Squibb collaboration terminates when Bristol-Myers Squibb no longer has an obliga-

tion to pay us royalties, which obligation generally continues until the later of the expiration of the Bristol-
Myers Squibb patent covering a product utilizing our cell line or ten years after commercial sales of that
product began.

The University of Minnesota license agreement terminates when the last patent licensed to us expires. We
may terminate the license agreement at any time. The University of Minnesota may terminate the license if we
fail to pay royalties when due or fail to perform the material terms of the license, such as our obligation to
use commercially reasonable efforts to commercialize the MultiStem technology.

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If our collaborators do not devote sufficient time and resources to successfully carry out their contracted
duties or meet expected deadlines, we may not be able to advance our product candidates in a timely
manner or at all.

Our success depends on the performance by our collaborators of their responsibilities under our

collaboration arrangements. Some potential collaborators may not perform their obligations in a timely fashion
or in a manner satisfactory to us. Typically, we cannot control the amount of resources or time our
collaborators may devote to our programs or potential products that may be developed in collaboration with
us. We are currently involved in multiple research and development collaborations with academic and research
institutions. These collaborators frequently depend on outside sources of funding to conduct or complete
research and development, such as grants or other awards. In addition, our academic collaborators may depend
on graduate students, medical students, or research assistants to conduct certain work, and such individuals
may not be fully trained or experienced in certain areas, or they may elect to discontinue their participation in
a particular research program, creating an inability to complete ongoing research in a timely and efficient
manner. As a result of these uncertainties, we are unable to control the precise timing and execution of any
experiments that may be conducted.

Additionally, our current or future corporate collaborators will retain the ability to pursue other research,
product development or commercial opportunities that may be directly competitive with our programs. If these
collaborators elect to prioritize or pursue other programs in lieu of ours, we may not be able to advance
product development programs in an efficient or effective manner, if at all. If a collaborator is pursuing a
competitive program and encounters unexpected financial or capability limitations, they may be motivated to
reduce the priority placed on our programs or delay certain activities related to our programs or be unwilling
to properly fund their share of the development expenses for our programs. Any of these developments could
harm our product and technology development efforts, which could seriously harm our business.

Under the terms of our collaboration agreement with Angiotech, either party may choose, following the

completion of Phase I studies, to opt-out of its obligation to fund further product development on a
product-by-product basis, provided no clinical studies concerning such product candidate are currently
ongoing. If Angiotech should decide to opt-out of funding the development of any of the product candidates
for the covered indications, for any reason, we may be unable to fund the development on our own and could
be forced to halt one or more MultiStem development programs.

Even if we or our collaborators receive regulatory approval for our products, those products may never
be commercially successful.

Even if we develop pharmaceuticals or MultiStem related products that obtain the necessary regulatory
approval, and we have access to the necessary manufacturing, sales, marketing and distribution capabilities
that we need, our success depends to a significant degree upon the commercial success of those products. If
these products fail to achieve or subsequently maintain market acceptance or commercial viability, our
business would be significantly harmed because our future royalty revenue or other revenue would be
dependent upon sales of these products. Many factors may affect the market acceptance and commercial
success of any potential products that we may discover, including:

(cid:129) health concerns, whether actual or perceived, or unfavorable publicity regarding our obesity drugs, stem

cell products or those of our competitors;

(cid:129) the timing of market entry as compared to competitive products;

(cid:129) the rate of adoption of products by our collaborators and other companies in the industry;

(cid:129) any product labeling that may be required by the FDA or other United States or foreign regulatory

agencies for our products or competing or comparable products;

(cid:129) convenience and ease of administration;

(cid:129) pricing;

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(cid:129) perceived efficacy and side effects;

(cid:129) marketing;

(cid:129) availability of alternative treatments;

(cid:129) levels of reimbursement and insurance coverage; and

(cid:129) activities by our competitors.

We may experience delays in clinical trials and regulatory approval relating to our products that could
adversely affect our financial results and our commercial prospects for our pharmaceutical or stem cell
products.

In addition to the regulatory requirements for our pharmaceutical programs, we will also require

regulatory approvals for each distinct application of our stem cell product. In each case, we will be required to
conduct clinical trials to demonstrate safety and efficacy of MultiStem, or various products that incorporate or
use MultiStem. For product candidates that advance to clinical testing, we cannot be certain that we or a
collaborator will successfully complete the clinical trials necessary to receive regulatory product approvals.
This process is lengthy and expensive.

We intend to seek approval for our pharmaceutical formulations through the FDA approval process. To

obtain regulatory approvals, we must, among other requirements, complete clinical trials showing that our
products are safe and effective for a particular indication. Under the approval process, we must submit clinical
and non-clinical data to demonstrate the medication is safe and effective. For example, we must be able to
provide data and information, including extended pharmacology, toxicology, reproductive toxicology, bioavail-
ability and genotoxicity studies to establish suitability for Phase II or large scale Phase III clinical trials.

All of our product candidates, including ATHX-105 and MultiStem, are at an early stage of development.

As these programs enter and progress through early stage clinical development, or complete additional
non-clinical testing, an indication of a lack of safety or lack of efficacy may result in the early termination of
an ongoing trial, or may cause us or any of our collaborators to forego further development of a particular
product candidate or program. The FDA or other regulatory agencies may require extensive clinical trials or
other testing prior to granting approval, which could be costly and time consuming to conduct. Any of these
developments would hinder, and potentially prohibit, our ability to commercialize our product candidates. We
cannot assure you that clinical trials will in fact demonstrate that our products are safe or effective.

Additionally, we may not be able to find acceptable patients or may experience delays in enrolling
patients for our currently planned or any future clinical trials. The FDA or we may suspend our clinical trials
at any time if either believes that we are exposing the subjects participating in the trials to unacceptable health
risks. The FDA or institutional review boards and/or institutional biosafety committees at the medical
institutions and healthcare facilities where we seek to sponsor clinical trials may not permit a trial to proceed
or may suspend any trial indefinitely if they find deficiencies in the conduct of the trials.

Product development costs to us and our potential collaborators will increase if we have delays in testing
or approvals or if we need to perform more or larger clinical trials than planned. We expect to continue to rely
on third party clinical investigators at medical institutions and healthcare facilities to conduct our clinical
trials, and, as a result, we may face additional delaying factors outside our control. Significant delays may
adversely affect our financial results and the commercial prospects for our product candidates and delay our
ability to become profitable.

If our pharmaceutical product candidates do not successfully complete the clinical trial process, we will
not be able to partner or market them. Even successful clinical trials may not result in a partnering
transaction or a marketable product and may not be entirely indicative of a product’s safety or efficacy.

Many factors, known and unknown, can adversely affect clinical trials and the ability to evaluate a
product’s efficacy. During the course of treatment, patients can die or suffer other adverse events for reasons
that may or may not be related to the proposed product being tested. Even if unrelated to our product, certain

23

events can nevertheless adversely impact our clinical trials. As a result, our ability to ultimately develop and
market the products and obtain revenues would suffer.

Even promising results in preclinical studies and initial clinical trials do not ensure successful results in

later clinical trials, which test broader human use of our products. Many companies in our industry have
suffered significant setbacks in advanced clinical trials, despite promising results in earlier trials. Even
successful clinical trials may not result in a marketable product or be indicative of the efficacy or safety of a
product. Many factors or variables could affect the results of clinical trials and cause them to appear more
promising than they may otherwise be. Product candidates that successfully complete clinical trials could
ultimately be found to be unsafe or ineffective.

In addition, our ability to complete clinical trials depends on many factors, including obtaining adequate

clinical supplies and having a sufficient rate of patient recruitment. For example, patient recruitment is a
function of many factors, including:

(cid:129) the size of the patient population;

(cid:129) the proximity of patients to clinical sites;

(cid:129) the eligibility criteria for the trial;

(cid:129) the perceptions of investigators and patients regarding safety; and

(cid:129) the availability of other treatment options.

Even if we obtain regulatory approval of any of our product candidates, the approved products may be
subject to post-approval studies and will remain subject to ongoing regulatory requirements. If we fail to
comply, or if concerns are identified in subsequent studies, our approval could be withdrawn and our
product sales could be suspended.

If we are successful at obtaining regulatory approval for ATHX-105, MultiStem or any of our other
product candidates, regulatory agencies in the United States and other countries where a product will be sold
may require extensive additional clinical trials or post-approval clinical studies that are expensive and time
consuming to conduct. In particular, therapeutic products administered for the treatment of persistent or
chronic conditions, such as ATHX-105 for obesity, are likely to require extensive follow-up studies and close
monitoring of patients after regulatory approval has been granted, for any signs of adverse effects that occur
over a long period of time. These studies may be expensive and time consuming to conduct and may reveal
side effects or other harmful effects in patients that use our therapeutic products after they are on the market,
which may result in the limitation or withdrawal of our drugs from the market. Alternatively, we may not be
able to conduct such additional trials, which might force us to abandon our efforts to develop or commercialize
certain product candidates. Even if post-approval studies are not requested or required, after our products are
approved and on the market, there might be safety issues that emerge over time that require a change in
product labeling or that require withdrawal of the product from the market, which would cause our revenue to
decline.

Additionally, any products that we may successfully develop will be subject to ongoing regulatory
requirements after they are approved. These requirements will govern the manufacturing, packaging, market-
ing, distribution, and use of our products. If we fail to comply with such regulatory requirements, approval for
our products may be withdrawn, and product sales may be suspended. We may not be able to regain
compliance, or we may only be able to regain compliance after a lengthy delay, significant expense, lost
revenues and damage to our reputation.

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We will rely on third parties to manufacture our pharmaceutical product candidates and our MultiStem
product candidate. There can be no guarantee that we can obtain sufficient and acceptable quantities of
our pharmaceutical product candidates or of our MultiStem product candidate on acceptable terms,
which may delay or impair our ability to develop, test and market such products.

Our business strategy relies on third parties to manufacture and produce our pharmaceutical product
candidates and MultiStem product candidate in accordance with good manufacturing practices established by
the FDA, or similar regulations in other countries. Our pharmaceutical product candidates or MultiStem
product may be in competition with other products or companies for access to these facilities and may be
subject to delays in manufacture if third parties give other products greater priority than our product
candidates. These third parties may not deliver sufficient quantities of our pharmaceutical or MultiStem
product candidates, manufacture our pharmaceutical and MultiStem product candidates in accordance with
specifications, or comply with applicable government regulations. Additionally, if the manufactured products
fail to perform as specified, our business and reputation could be severely impacted.

We expect to enter into additional manufacturing agreements for the production of product materials. If
any manufacturing agreement is terminated or any third party collaborator experiences a significant problem
that could result in a delay or interruption in the supply of product materials to us, there are very few contract
manufacturers who currently have the capability to produce our pharmaceutical product candidates or
MultiStem product on acceptable terms, or on a timely and cost-effective basis. We cannot assure you that
manufacturers on whom we will depend will be able to successfully produce our pharmaceutical product
candidates or MultiStem product on acceptable terms, or on a timely or cost-effective basis. We cannot assure
you that manufacturers will be able to manufacture our products in accordance with our product specifications
or will meet FDA or other requirements. We must have sufficient and acceptable quantities of our product
materials to conduct our clinical trials and to market our product candidates, if and when such products have
been approved by the FDA for marketing. If we are unable to obtain sufficient and acceptable quantities of
our product material, we may be required to delay the clinical testing and marketing of our products.

If our contract manufacturers are not satisfying our needs and we decide not to establish our own
manufacturing capabilities, it could be difficult and very expensive to change suppliers. Any change in the
location of manufacturing would require FDA inspection and approval, which could interrupt the supply of
products and may be time-consuming and expensive to obtain. If we are unable to identify alternative contract
manufacturers that are qualified to produce our products, we may have to temporarily suspend the production
of products, and would be unable to generate revenue from the sale of products.

If we do not comply with applicable regulatory requirements in the manufacture and distribution of our
product candidates, we may incur penalties that may inhibit our ability to commercialize our products
and adversely affect our revenue.

Our failure or the failure of our potential collaborators or third party manufacturers to comply with

applicable FDA or other regulatory requirements including manufacturing, quality control, labeling, safety
surveillance, promoting and reporting may result in criminal prosecution, civil penalties, recall or seizure of
our products, total or partial suspension of production or an injunction, as well as other regulatory action
against our product candidates or us. Discovery of previously unknown problems with a product, supplier,
manufacturer or facility may result in restrictions on the sale of our products, including a withdrawal of such
products from the market. The occurrence of any of these events would negatively impact our business and
results of operations.

If we are unable to create and maintain sales, marketing and distribution capabilities or enter into
agreements with third parties to perform those functions, we will not be able to commercialize our
product candidates.

We currently have no sales, marketing or distribution capabilities. Therefore, to commercialize our
product candidates, if and when such products have been approved and are ready for marketing, we expect to
collaborate with third parties to perform these functions. We will either need to share the value generated from

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the sale of any products and/or pay a fee to the contract sales organization. If we establish any such
relationships, we will be dependent upon the capabilities of our collaborators or contract service providers to
effectively market, sell, and distribute our product. If they are ineffective at selling and distributing our
product, or if they choose to emphasize other products over ours, we may not achieve the level of product
sales revenues that we would like. If conflicts arise, we may not be able to resolve them easily or effectively,
and we may suffer financially as a result. If we cannot rely on the sales, marketing and distribution capabilities
of our collaborators or of contract service providers, we may be forced to establish our own capabilities. We
have no experience in developing, training or managing a sales force and will incur substantial additional
expenses if we decide to market any of our future products directly. Developing a marketing and sales force is
also time consuming and could delay launch of our future products. In addition, we will compete with many
companies that currently have extensive and well-funded marketing and sales operations. Our marketing and
sales efforts may be unable to compete successfully against these companies.

If we are unable to attract and retain key personnel and advisors, it may adversely affect our ability to
obtain financing, pursue collaborations or develop our product candidates.

We are highly dependent on Gil Van Bokkelen, Ph.D., our Chief Executive Officer, as well as other

executive and scientific officers, including William Lehmann, J.D., M.B.A., President and Chief Operating
Officer, John Harrington, Ph.D., Chief Scientific Officer and Executive Vice President, Robert Deans, Ph.D.,
Senior Vice President, Regenerative Medicine, and Laura Campbell, CPA, Vice President of Finance.

These individuals are integral to the development and integration of our technologies and to our present

and future scientific collaborations, including managing the complex research processes and the product
development and potential commercialization processes. Given their leadership, extensive technical, scientific
and financial expertise and management and operational experience, these individuals would be difficult to
replace. Consequently, the loss of services of one or more of these individuals could result in product
development delays or the failure of our collaborations with current and future collaborators, which, in turn,
may hurt our ability to develop and commercialize products and generate revenues.

Our future success depends on our ability to attract, retain and motivate highly qualified management and

scientific, development and commercial personnel and advisors. If we are unable to attract and retain key
personnel and advisors, it may negatively affect our ability to successfully develop, test and commercialize our
product candidates.

Our ability to compete in the biopharmaceutical market may decline if we do not adequately protect our
proprietary technologies.

Our success depends in part on our ability to obtain and maintain intellectual property that protects our

technologies and our pharmaceutical products. Patent positions may be highly uncertain and may involve
complex legal and factual questions, including the ability to establish patentability of compounds and methods
for using them for which we seek patent protection. We cannot predict the breadth of claims that will
ultimately be allowed in our patent applications, if any, including those we have in-licensed or the extent to
which we may enforce these claims against our competitors. We have filed four patent applications that seek
to protect the composition of matter and method of use related to ATHX-105, as well as other compounds that
we have identified in the same class. In addition, we are prosecuting more than 20 distinct patent applications
directed to composition, methods of production, and methods of use of MultiStem and related technologies.
We have also filed four patent applications with claims directed to compounds from our histamine H3
program. If we are unsuccessful in obtaining these patents, we may ultimately be unable to commercialize
ATHX-105 or MultiStem or other products that we are developing or may elect to develop in the future.

The degree of future protection for our proprietary rights is therefore highly uncertain and we cannot

assure you that:

(cid:129) we were the first to file patent applications or to invent the subject matter claimed in patent applications

relating to the technologies or product candidates upon which we rely;

26

(cid:129) others will not independently develop similar or alternative technologies or duplicate any of our

technologies;

(cid:129) others did not publicly disclose our claimed technology before we conceived the subject matter included

in any of our patent applications;

(cid:129) any of our pending or future patent applications will result in issued patents;

(cid:129) any of our patent applications will not result in interferences or disputes with third parties regarding

priority of invention;

(cid:129) any patents that may be issued to us, our collaborators or our licensors will provide a basis for
commercially viable products or will provide us with any competitive advantages or will not be
challenged by third parties;

(cid:129) we will develop additional proprietary technologies that are patentable;

(cid:129) the patents of others will not have an adverse effect on our ability to do business; or

(cid:129) new proprietary technologies from third parties, including existing licensors, will be available for

licensing to us on reasonable commercial terms, if at all.

In addition, patent law outside the United States is uncertain and in many countries intellectual property

laws are undergoing review and revision. The laws of some countries do not protect intellectual property rights
to the same extent as domestic laws. It may be necessary or useful for us to participate in opposition
proceedings to determine the validity of our competitors’ patents or to defend the validity of any of our or our
licensor’s future patents, which could result in substantial costs and would divert our efforts and attention from
other aspects of our business. With respect to certain of our inventions, we have decided not to pursue patent
protection outside the United States, both because we do not believe it is cost effective and because of
confidentiality concerns. Accordingly, our international competitors could develop and receive foreign patent
protection for gene sequences and functions for which we are seeking U.S. patent protection, enabling them to
sell products that we have developed.

Technologies licensed to us by others, or in-licensed technologies, are important to our business. The
scope of our rights under our licenses may be subject to dispute by our licensors or third parties. Our rights to
use these technologies and to practice the inventions claimed in the licensed patents are subject to our
licensors abiding by the terms of those licenses and not terminating them. In particular, we depend on certain
technologies relating to our MultiStem technology licensed from the University of Minnesota. As a result of
this license, we have agreed to use commercially reasonable efforts to develop and commercialize this
technology. If we fail to comply with those obligations, we may lose some of the rights that enable us to
utilize this technology, and our ability to develop products based on MultiStem could be seriously hampered.

In addition, we may in the future acquire rights to additional technologies by licensing such rights from
existing licensors or from third parties. Such in-licenses may be costly. Also, we generally do not control the
patent prosecution, maintenance or enforcement of in-licensed technologies. Accordingly, we are unable to
exercise the same degree of control over this intellectual property as we do over our internally developed
technologies. Moreover, some of our academic institution licensors, collaborators and scientific advisors have
rights to publish data and information to which we have rights. If we cannot maintain the confidentiality of
our technologies and other confidential information in connection with our collaborations, our ability to protect
our proprietary information or obtain patent protection in the future may be impaired, which could have a
significant adverse effect on our business, financial condition and results of operations.

We may not have adequate protection for our unpatented proprietary information, which could adversely
affect our competitive position.

In addition to patents, we will substantially rely on trade secrets, know-how, continuing technological
innovations and licensing opportunities to develop and maintain our competitive position. However, others
may independently develop substantially equivalent proprietary information and techniques or otherwise gain

27

access to our trade secrets or disclose our technology. To protect our trade secrets, we may enter into
confidentiality agreements with employees, consultants and potential collaborators. However, these agreements
may not provide meaningful protection of our trade secrets or adequate remedies in the event of unauthorized
use or disclosure of such information. Likewise, our trade secrets or know-how may become known through
other means or be independently discovered by our competitors. Any of these events could prevent us from
developing or commercializing our product candidates.

Disputes concerning the infringement or misappropriation of our proprietary rights or the proprietary
rights of others could be time consuming and extremely costly and could delay our research and
development efforts.

Our commercial success, if any, will be significantly harmed if we infringe the patent rights of third
parties or if we breach any license or other agreements that we have entered into with regard to our technology
or business.

We are aware of other companies and academic institutions that have been performing research in the
areas of adult derived stem cells. In particular, other companies and academic institutions have announced that
they have identified nonembryonic stem cells isolated from bone marrow or other tissues that have the ability
to form a range of cell types, or display the property of pluripotency. To the extent any of these companies or
academic institutions currently have, or obtain in the future, broad patent claims, such patents could block our
ability to use various aspects of our discovery and development process and might prevent us from developing
or commercializing newly discovered applications of our MultiStem technology, or otherwise conducting our
business. In addition, it is possible that some of the pharmaceutical product candidates we are developing may
not be patentable or may be covered by intellectual property of third parties.

We are not currently a party to any litigation, interference, opposition, protest, reexamination or any other

potentially adverse governmental, ex parte or inter-party proceeding with regard to our patent or trademark
positions. However, the life sciences and other technology industries are characterized by extensive litigation
regarding patents and other intellectual property rights. Many life sciences and other technology companies
have employed intellectual property litigation as a way to gain a competitive advantage. If we become
involved in litigation, interference proceedings, oppositions, reexamination, protest or other potentially adverse
intellectual property proceedings as a result of alleged infringement by us of the rights of others or as a result
of priority of invention disputes with third parties, we might have to spend significant amounts of money, time
and effort defending our position and we may not be successful. In addition, any claims relating to the
infringement of third-party proprietary rights or proprietary determinations, even if not meritorious, could
result in costly litigation, lengthy governmental proceedings, divert management’s attention and resources, or
require us to enter into royalty or license agreements that are not advantageous to us. If we do not have the
financial resources to support such litigation or appeals, we may forfeit or lose certain commercial rights.
Even if we have the financial resources to continue such litigation or appeals, we may lose. In the event that
we lose, we may be forced to pay very substantial damages; we may have to obtain costly license rights,
which may not be available to us on acceptable terms, if at all; or we may be prohibited from selling products
that are found to infringe the patent rights of others.

Should any person have filed patent applications or obtained patents that claim inventions also claimed by
us, we may have to participate in an interference proceeding declared by the relevant patent regulatory agency
to determine priority of invention and, thus, the right to a patent for these inventions in the United States.
Such a proceeding could result in substantial cost to us even if the outcome is favorable. Even if successful on
priority grounds, an interference action may result in loss of claims based on patentability grounds raised in
the interference action. Litigation, interference proceedings or other proceedings could divert management’s
time and efforts. Even unsuccessful claims could result in significant legal fees and other expenses, diversion
of management’s time and disruption in our business. Uncertainties resulting from initiation and continuation
of any patent proceeding or related litigation could harm our ability to compete and could have a significant
adverse effect on our business, financial condition and results of operations.

28

An adverse ruling arising out of any intellectual property dispute, including an adverse decision as to the

priority of our inventions, could undercut or invalidate our intellectual property position. An adverse ruling
could also subject us to significant liability for damages, including possible treble damages, prevent us from
using technologies or developing products, or require us to negotiate licenses to disputed rights from third
parties. Although patent and intellectual property disputes in the technology area are often settled through
licensing or similar arrangements, costs associated with these arrangements may be substantial and could
include license fees and ongoing royalties. Furthermore, necessary licenses may not be available to us on
satisfactory terms, if at all. Failure to obtain a license in such a case could have a significant adverse effect on
our business, financial condition and results of operations.

Many potential competitors, including those who have greater resources and experience than we do, may
develop products or technologies that make ours obsolete or noncompetitive.

Many companies are engaged in the pursuit of safe and effective obesity drugs. Our future success will
depend on our ability to maintain a competitive position with respect to technological advances. Technological
developments by others may result in our MultiStem product platform and technologies, as well as our
pharmaceutical formulations, such as ATHX-105, becoming obsolete.

We are subject to significant competition from pharmaceutical, biotechnology and diagnostic companies,

academic and research institutions, and government or other publicly funded agencies that are pursuing the
development of therapeutic products and technologies that are substantially similar to our proposed therapeutic
products and technologies, or that otherwise address the indications we are pursuing. Our most significant
competitors include major pharmaceutical companies such as Pfizer, Bristol-Myers Squibb, Merck, Roche,
Sanofi-Aventis and GlaxoSmithKline as well as smaller biotechnology or biopharmaceutical companies such
as Arena Pharmaceuticals, Orexigen, Vivus, Osiris, Geron, Aastrom, Stem Cells Inc., Viacell and Cytori
Therapeutics. Most of our current and potential competitors have substantially greater research and develop-
ment capabilities and financial, scientific, regulatory, manufacturing, marketing, sales, human resources, and
experience than we do. Many of our competitors have several therapeutic products that have already been
developed, approved and successfully commercialized, or are in the process of obtaining regulatory approval
for their therapeutic products in the United States and internationally.

Many of these companies have substantially greater capital resources, research and development resources

and experience, manufacturing capabilities, regulatory expertise, sales and marketing resources, established
relationships with consumer products companies and production facilities.

Universities and public and private research institutions are also potential competitors. While these
organizations primarily have educational objectives, they may develop proprietary technologies related to stem
cells or secure patent protection that we may need for the development of our technologies and products. We
may attempt to license these proprietary technologies, but these licenses may not be available to us on
acceptable terms, if at all.

Our competitors, either alone or with their collaborative partners, may succeed in developing technologies

or products that are more effective, safer, more affordable or more easily commercialized than ours, and our
competitors may obtain intellectual property protection or commercialize products sooner than we do.
Developments by others may render our product candidates or our technologies obsolete.

Our current product discovery and development collaborators are not prohibited from entering into research

and development collaboration agreements with third parties in any product field. Our failure to compete
effectively would have a significant adverse effect on our business, financial condition and results of operations.

We will use hazardous and biological materials in our business. Any claims relating to improper
handling, storage or disposal of these materials could be time consuming and costly.

Our products and processes will involve the controlled storage, use and disposal of certain hazardous and

biological materials and waste products. We and our suppliers and other collaborators are subject to federal,
state and local regulations governing the use, manufacture, storage, handling and disposal of materials and

29

waste products. Even if we and these suppliers and collaborators comply with the standards prescribed by law
and regulation, the risk of accidental contamination or injury from hazardous materials cannot be completely
eliminated. In the event of an accident, we could be held liable for any damages that result, and any liability
could exceed the limits or fall outside the coverage of any insurance we may obtain and exceed our financial
resources. We may not be able to maintain insurance on acceptable terms, or at all. We may incur significant
costs to comply with current or future environmental laws and regulations.

If we acquire products, technologies or other businesses, we will incur a variety of costs, may have
integration difficulties and may experience numerous other risks that could adversely affect our business.

To remain competitive, we may decide to acquire additional businesses, products and technologies. We

currently have no commitments or agreements with respect to, and are not actively seeking, any material
acquisitions. We have limited experience in identifying acquisition targets, successfully acquiring them and
integrating them into our current infrastructure. We may not be able to successfully integrate any businesses,
products, technologies or personnel that we might acquire in the future without a significant expenditure of
operating, financial and management resources, if at all. In addition, future acquisitions could require
significant capital infusions and could involve many risks, including, but not limited to:

(cid:129) we may have to issue convertible debt or equity securities to complete an acquisition, which would

dilute our stockholders and could adversely affect the market price of the common stock;

(cid:129) an acquisition may negatively impact our results of operations because it may require us to incur large
one-time charges to earnings, amortize or write down amounts related to goodwill and other intangible
assets, or incur or assume substantial debt or liabilities, or it may cause adverse tax consequences,
substantial depreciation or deferred compensation charges;

(cid:129) we may encounter difficulties in assimilating and integrating the business, technologies, products,

personnel or operations of companies that we acquire;

(cid:129) certain acquisitions may disrupt our relationship with existing collaborators who are competitive to the

acquired business;

(cid:129) acquisitions may require significant capital infusions and the acquired businesses, products or technol-

ogies may not generate sufficient revenue to offset acquisition costs;

(cid:129) an acquisition may disrupt our ongoing business, divert resources, increase our expenses and distract

our management;

(cid:129) acquisitions may involve the entry into a geographic or business market in which we have little or no

prior experience; and

(cid:129) key personnel of an acquired company may decide not to work for us.

Any of the foregoing risks could have a significant adverse effect on our business, financial condition and

results of operations.

To the extent we enter markets outside of the United States, our business will be subject to political,
economic, legal and social risks in those markets, which could adversely affect our business.

There are significant regulatory and legal barriers in markets outside the United States that we must
overcome to the extent we enter or attempt to enter markets in countries other than the United States. We will
be subject to the burden of complying with a wide variety of national and local laws, including multiple and
possibly overlapping and conflicting laws. We also may experience difficulties adapting to new cultures,
business customs and legal systems. Any sales and operations outside the United States would be subject to
political, economic and social uncertainties including, among others:

(cid:129) changes and limits in import and export controls;

(cid:129) increases in custom duties and tariffs;

30

(cid:129) changes in currency exchange rates;

(cid:129) economic and political instability;

(cid:129) changes in government regulations and laws;

(cid:129) absence in some jurisdictions of effective laws to protect our intellectual property rights; and

(cid:129) currency transfer and other restrictions and regulations that may limit our ability to sell certain products

or repatriate profits to the United States.

Any changes related to these and other factors could adversely affect our business to the extent we enter

markets outside the United States.

Foreign governments often impose strict price controls on approved products, which may adversely affect
our future profitability in those countries, and the re-importation of drugs to the United States from
foreign countries that impose price controls may adversely affect our future profitability.

Frequently foreign governments impose strict price controls on newly approved therapeutic products. If
we obtain regulatory approval to sell products in foreign countries, we may be unable to obtain a price that
provides an adequate financial return on our investment. Furthermore, legislation in the United States may
permit re-importation of drugs from foreign countries into the United States, including re-importation from
foreign countries where the drugs are sold at lower prices than in the United States due to foreign
government-mandated price controls. Such a practice, especially if it is conducted on a widespread basis, may
significantly reduce our potential U.S. revenues from any drugs that we are able to develop.

If we elect not to sell our products in foreign countries that impose government mandated price controls
because we decide it is uneconomical to do so, a foreign government or patent office may attempt to
terminate our intellectual property rights in that country, enabling competitors to make and sell our
products.

In some cases we may choose not to sell a product in a foreign country because it is uneconomical to do
so under a system of government-imposed price controls, or because it could severely limit our profitability in
the U.S. or other markets. In such cases, a foreign government or patent office may terminate any intellectual
property rights we may obtain with respect to that product. Such a termination could enable competitors to
produce and sell our product in that market. Furthermore, such products may be exported into the United States
through legislation that authorizes the importation of drugs from outside the United States. In such an event,
we may have to reduce our prices, or we may be unable to compete with low-cost providers of our drugs, and
we could be financially harmed as a result.

We may encounter difficulties managing our growth, which could adversely affect our business.

At various times we have experienced periods of rapid growth in our employee numbers as a result of a

dramatic increase in activity in technology programs, genomics programs, collaborative research programs,
discovery programs, and scope of operations. At other times, we have had to reduce staff in order to bring our
expenses in line with our financial resources. Our success will also depend on the ability of our officers and
key employees to continue to improve our operational capabilities and our management information and
financial control systems, and to expand, train and manage our work force.

We may be sued for product liability, which could adversely affect our business.

Because our business strategy involves the development and sale by either us or our collaborators of
commercial products, we may be sued for product liability. We may be held liable if any product we develop
and commercialize, or any product our collaborators commercialize that incorporates any of our technology,
causes injury or is found otherwise unsuitable during product testing, manufacturing, marketing, sale or
consumer use. In addition, the safety studies we must perform and the regulatory approvals required to
commercialize our pharmaceutical products, will not protect us from any such liability.

31

We carry product liability insurance, as well as liability insurance for conducting clinical trials. Currently,

we carry a $5 million per event, $5 million annual aggregate coverage for both our products liability policy
and our clinical trials protection. We also intend to seek product liability insurance for any approved products
that we may develop or acquire. However, in the event there are product liability claims against us, our
insurance may be insufficient to cover the expense of defending against such claims, or may be insufficient to
pay or settle such claims. Furthermore, we may be unable to obtain adequate product liability insurance
coverage for commercial sales of any of our approved products. If such insurance is insufficient to protect us,
our results of operations will suffer. If any product liability claim is made against us, our reputation and future
sales will be damaged, even if we have adequate insurance coverage.

The availability, manner, and amount of reimbursement for our product candidates from government and
private payers are uncertain, and our inability to obtain adequate reimbursement for any products could
severely limit our product sales.

We expect that many of the patients who seek treatment with any of our products that are approved for

marketing will be eligible for Medicare benefits. Other patients may be covered by private health plans. If we
are unable to obtain or retain adequate levels of reimbursement from Medicare or from private health plans,
our ability to sell our products will be severely limited. The application of existing Medicare regulations and
interpretive coverage and payment determinations to newly approved products is uncertain and those
regulations and interpretive determinations are subject to change. The Medicare Prescription Drug Improve-
ment and Modernization Act, enacted in December 2003, provides for a change in reimbursement methodol-
ogy that reduces the Medicare reimbursement rates for many drugs, which may adversely affect
reimbursement for any products we may develop. Medicare regulations and interpretive determinations also
may determine who may be reimbursed for certain services, and may limit the pool of patients our product
candidates are being developed to serve.

Federal, state and foreign governments continue to propose legislation designed to contain or reduce
health care costs. Legislation and regulations affecting the pricing of products like our potential products may
change further or be adopted before any of our potential products are approved for marketing. Cost control
initiatives by governments or third-party payers could decrease the price that we receive for any one or all of
our potential products or increase patient coinsurance to a level that make our products under development
become unaffordable. In addition, government and private health plans persistently challenge the price and
cost-effectiveness of therapeutic products. Accordingly, these third parties may ultimately not consider any or
all of our products under development to be cost effective, which could result in products not being covered
under their health plans or covered only at a lower price. Any of these initiatives or developments could
prevent us from successfully marketing and selling any of our products that are approved for
commercialization.

Public perception of ethical and social issues surrounding the use of adult-derived stem cell technology
may limit or discourage the use of our technologies, which may reduce the demand for our therapeutic
products and technologies and reduce our revenues.

Our success will depend in part upon our ability to develop therapeutic products incorporating or
discovered through our adult-derived stem cell technology. For social, ethical, or other reasons, governmental
authorities in the United States and other countries may call for limits on, or regulation of the use of,
adult-derived stem cell technologies. Although we do not use the more controversial stem cells derived from
embryos or fetuses, claims that adult-derived stem cell technologies are ineffective, unethical or pose a danger
to the environment may influence public attitudes. The subject of stem cell technologies in general has
received negative publicity and aroused public debate in the United States and some other countries. Ethical
and other concerns about our adult-derived stem cell technology could materially hurt the market acceptance
of our therapeutic products and technologies, resulting in diminished sales and use of any products we are able
to develop using adult-derived stem cells.

32

ITEM 1B. UNRESOLVED STAFF COMMENTS

Not applicable.

ITEM 2. PROPERTIES

Our principal offices are located at 3201 Carnegie Avenue in Cleveland, Ohio. We currently lease

approximately 53,000 square feet of space for our corporate offices and laboratories, with about 40,000 square
feet of state-of-the-art laboratory space. The lease currently expires in March 2010, and we have an option to
extend the lease in annual increments through March 2013 at our current rent of $267,000 per year. In 2008,
we entered into a three-year lease agreement for office and laboratory space for our Belgian subsidiary, with
an annual rent of approximately $45,000, subject to annual adjustments based on an inflationary index. The
lease includes an option to renew for four additional years through December 31, 2014.

ITEM 3. LEGAL PROCEEDINGS

From time to time, we may become subject to various legal proceedings that are incidental to the ordinary

conduct of our business. Currently, there are no such proceedings.

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

No matter was submitted to a vote of security holders during the fourth quarter of 2007.

ITEM 4A. EXECUTIVE OFFICERS OF THE REGISTRANT

The information under this Item is furnished pursuant to Instruction 3 to Item 401(b) of Regulation S-K.

There exists no arrangement or understanding between any executive officer and any other person
pursuant to which such executive officer was elected. Each executive officer serves until his or her successor
is elected and qualified.

The following sets forth the name, age, current position and principal occupation and employment during

the past five years of our executive officers.

Gil Van Bokkelen, Ph.D.
Age: 47

Dr. Van Bokkelen has served as our Chief Executive Officer and Chairman since June 2007. Dr. Van
Bokkelen co-founded Athersys in October 1995 and served as Chief Executive Officer and Director since
Athersys’ founding. Prior to May 2006, he also served as Athersys’ President. He has served as Chairman of
Athersys’ board of directors since August 2000. Dr. Van Bokkelen is the current Chairman of the Center for
Stem Cells and Regenerative Medicine, and has served on a number of other boards, including the
Biotechnology Industry Organization’s ECS board of directors from 2001 to 2004 and the Kent State
University Board of Trustees from 2001 to 2004, and has served as an advisor to venture capital firms and
non-profit organizations. He received his Ph.D. in Genetics from Stanford University, his B.A. in Economics
from the University of California at Berkeley, and his B.A. in Molecular Biology from the University of
California at Berkeley.

William (BJ) Lehmann, Jr., J.D.
Age: 42

Mr. Lehmann has served as our President and Chief Operating Officer since June 2007. Mr. Lehmann
joined Athersys in September 2001 and was Athersys’ Executive Vice President of Corporate Development
and Finance from August 2002 until May 2006, when he became Athersys’ President and Chief Operating
Officer. From 1994 to 2001, Mr. Lehmann was with McKinsey & Company, Inc., an international management
consulting firm, where he worked extensively with new technology and service-based businesses in the firm’s
Business Building practice. Prior to joining McKinsey, he worked at Wilson, Sonsini, Goodrich & Rosati, a

33

Silicon Valley law firm, and worked with First Chicago Corporation, a financial institution. Mr. Lehmann
received his J.D. from Stanford University, his M.B.A. from the University of Chicago, and his B.A. from the
University of Notre Dame.

John J. Harrington, Ph.D.
Age: 40

Dr.. Harrington has served as our Chief Scientific Officer, Executive Vice President and Director since
June 2007. Dr. Harrington co-founded Athersys in October 1995 and has served as Athersys’ Executive Vice
President and Chief Scientific Officer and as Director since Athersys’ founding. Dr. Harrington led the
development of the RAGE technology as well as its application for gene discovery, drug discovery and
commercial protein production applications. He is a listed inventor on 20 issued or pending U.S. patents, has
authored 20 scientific publications, and has received numerous awards for his work, including being named
one of the top international young scientists by MIT Technology Review in 2002. Dr. Harrington has overseen
the therapeutic product development programs at Athersys since their inception, and during his career he has
also held positions at Amgen and Scripps Clinic. He received his Ph.D. in Cancer Biology from Stanford
University and his B.A. in Biochemistry and Cell Biology from the University of California at San Diego.

Robert J. Deans, Ph.D.
Age: 56

Dr. Deans has served as our Senior Vice President, Regenerative Medicine since June 2007. Dr. Deans

has led Athersys’ regenerative medicine research and development activities since February 2003 and has
served as Vice President of Regenerative Medicine since October 2003. He was named Senior Vice President
of Regenerative Medicine in June 2006. Dr. Deans is highly regarded as an expert in stem cell therapeutics,
with over fifteen years of experience in this field. From 2001 to 2003, Dr. Deans worked for early-stage
biotechnology companies. Dr. Deans was formerly the Vice President of Research at Osiris Therapeutics, Inc.,
a biotechnology company, from 1998 to 2001 and Director of Research and Development with the Immuno-
therapy Division of Baxter International, Inc., a global healthcare company, from 1992 to 1998. Dr. Deans was
also previously on faculty at USC Medical School in Los Angeles, between 1981 and 1998, in the departments
of Microbiology and Neurology at the Norris Comprehensive Cancer Center. Dr. Deans was an undergraduate
at MIT, received his Ph.D. at the University of Michigan, and did his post-doctoral work at UCLA in Los
Angeles.

Laura K. Campbell, CPA
Age: 44

Ms. Campbell has served as our Vice President, Finance since June 2007. Ms. Campbell joined Athersys

in January 1998 as Controller and has served as Vice President of Finance since May 2006. Prior to joining
Athersys, she was at Ernst & Young LLP, a public accounting firm, for 11 years, in the audit practice. During
her tenure with Ernst & Young LLP, Ms. Campbell specialized in entrepreneurial services and the biotechnol-
ogy industry sector and participated in several initial public offerings. Ms. Campbell received her B.S., with
distinction, in Business Administration from The Ohio State University.

34

PART II

ITEM 5. MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS

AND ISSUER PURCHASES OF EQUITY SECURITIES

Prior to the merger with BTHC VI, Inc., BTHC VI was a shell company with no operations and no or
nominal assets. BTHC VI’s common stock was eligible for trading on the OTC Bulletin Board, although no
trading took place prior to the merger because none of BTHC VI’s then-outstanding shares were able to be
transferred under the terms of BTHC VI’s bankruptcy plan until the merger was consummated. From June 8,
2007 to December 11, 2007, our common stock was quoted on the OTC Bulletin Board under the symbol
“AHYS” at the following prices:

High

Low

Year ending December 31, 2007:
Second Quarter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Third Quarter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fourth Quarter (through December 11, 2007) . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$10.00
$ 8.75
$ 8.00

$5.25
$7.00
$4.40

These over-the-counter market quotations reflect inter-dealer prices, without retail mark-up, mark-down or

commission and may not necessarily represent actual transactions.

Since December 12, 2007, our common stock has been traded on the NASDAQ Capital Market under the

symbol “ATHX.” Set forth below are the high and low sale prices for our common stock on the NASDAQ
Capital Market for the period indicated.

High

Low

Year ending December 31, 2007:
Fourth Quarter (from December 12, 2007 through December 31, 2007) . . . . . . . . . . $5.01

$3.51

Holders

As of February 29, 2008, the number of holders of record was approximately 938, one of which is Cede &

Co., a nominee for The Depository Trust Company, or DTC. Shares of common stock that are held by
financial institutions as nominees for beneficial owners are deposited into participant accounts at DTC, and are
considered to be held by record by Cede & Co., as one stockholder.

Dividend Policy

All of our assets consist of the capital stock of ABT Holding Company. We would have to rely upon
dividends and other payments from ABT Holding Company to generate the funds necessary to make dividend
payments, if any, on our common stock. ABT Holding Company, however, is legally distinct from us and has
no obligation to pay amounts to us. The ability of ABT Holding Company to make dividend and other
payments to us is subject to, among other things, the availability of funds, the terms of our indebtedness and
applicable state laws. We did not pay cash dividends on our common stock during the past two years. We do
not anticipate that we will pay any dividends on our common stock in the foreseeable future. Rather, we
anticipate that we will retain earnings, if any, for use in the development of our business.

35

ITEM 6. SELECTED FINANCIAL DATA

2003

Year Ended December 31,
2006

2004
(In thousands, except per share data)

2005

Consolidated Statement of Operations Data:
Revenues:

License fees . . . . . . . . . . . . . . . . . . . . . . . . . .
Grants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 1,393
759

$

Total revenues . . . . . . . . . . . . . . . . . . . . . . . . . . .
Costs and expenses:

Research and development . . . . . . . . . . . . . . . .
Purchased in-process R&D. . . . . . . . . . . . . . . .
General and administrative . . . . . . . . . . . . . . . .
Depreciation . . . . . . . . . . . . . . . . . . . . . . . . . .
Restructuring costs . . . . . . . . . . . . . . . . . . . . .

2,152

13,675
9,500
10,882
1,803
1,076

820
2,318

3,138

$

763
2,833

3,596

12,415
—
4,717
1,297
107

12,578
—
3,755
982
251

$

1,908 $
1,817

3,725

9,741
—
3,347
528
—

2007

1,433
1,827

3,260

15,817
—
7,975
283
—

Loss from operations . . . . . . . . . . . . . . . .

(34,784)

(15,398)

(13,970)

(9,891)

(20,815)

Other income (expense):

Other income and equity in earnings of

unconsolidated affiliate. . . . . . . . . . . . . . . . .
Interest income . . . . . . . . . . . . . . . . . . . . . . . .
Interest expense . . . . . . . . . . . . . . . . . . . . . . . .
Accretion of premium on convertible debt . . . .

Loss before cumulative effect of change in

1,114
644
(135)
—

—
317
(73)
—

18
317
(964)
—

208
119
(1,047)
(260)

2,017
1,591
(1,263)
(456)

accounting principle. . . . . . . . . . . . . . . . . . . . .

$ (33,161) $ (15,154) $ (14,599) $ (10,871) $

(18,926)

Cumulative effect of change in accounting

principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

—

—

—

306

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preferred stock dividends. . . . . . . . . . . . . . . . . . .
Deemed dividend resulting from induced

conversion of convertible preferred stock . . . . .

(33,161)
(2,164)

(15,154)
(2,325)

(14,599)
(2,253)

(10,565)
(1,408)

—

(18,926)
(659)

—

—

—

—

(4,800)

Net loss attributable to common stockholders . .

$ (35,325) $ (17,479) $ (16,852) $ (11,973) $

(24,385)

Basic and diluted net loss per common share

attributable to common stockholders:
Loss before cumulative effect of change in

accounting principle. . . . . . . . . . . . . . . . . . . . .

$ (130.90) $ (59.82) $ (57.79) $ (41.89) $

(2.26)

Cumulative effect of change in accounting

principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

—

—

—

1.05

—

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

$ (130.90) $ (59.82) $ (57.79) $ (40.84) $

(2.26)

Weighted average shares outstanding, basic and

diluted. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

269,861

292,173

291,612

293,142

10,811,119

36

2003

2004

December 31,
2005

2006

2007

Consolidated Balance Sheet Data:
Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . $ 4,580
670
Restricted cash . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18,909
Available-for-sale securities (short-term) . . . . . . . . . .
18,514
Working capital (deficit) . . . . . . . . . . . . . . . . . . . . . .
1,833
Available-for-sale securities (long-term) . . . . . . . . . . .
30,503
Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
578
Long-term obligations, less current portion . . . . . . . .
8,911
Accrued dividends . . . . . . . . . . . . . . . . . . . . . . . . . .
14,951
Total stockholders’ equity (deficit). . . . . . . . . . . . . . .

$ 3,303
—
13,976
17,018
—
20,894
7,215
11,236
1,151

$ 1,080
—
3,481
1,828
—
7,309
4,684
7,473
(8,584)

(3,206)

$13,248
$ 1,528
—
—
— 22,477
32,849
— 13,850
52,225
—
—
47,631

4,266
9,310
8,882
(20,007)

ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND

RESULTS OF OPERATIONS

You should read the following discussion and analysis in conjunction with “Item 8. Financial Statements

and Supplementary Data” included below in this annual report on Form 10-K.

Overview

We are a biopharmaceutical company engaged in the discovery and development of therapeutic product

candidates designed to extend and enhance the quality of human life. Through the application of our
proprietary technologies, we have established a pipeline of therapeutic product development programs in
multiple diseases. In July 2007, we initiated a Phase I clinical trial in the United Kingdom with our lead
candidate in clinical development (ATHX-105 for the treatment of obesity), and completed this trial in January
2008. In the fourth quarter of 2007, we received FDA authorization to advance two MultiStem product
development programs into clinical trials, in the areas of HSC transplant support, and for treatment of damage
from myocardial infarction. The application of MultiStem for certain cardiovascular applications, including
myocardial infarction and peripheral vascular disease, is being developed with our partner, Angiotech. We
intend to initiate both of these trials in 2008, and file an additional IND for treatment of ischemic stroke in
2008. We are also developing pharmaceutical products for the treatment of certain conditions affecting the
central nervous system, such as ADHD, narcolepsy and other cognitive or attention disorders. In addition to
these drug development programs, we are also developing MultiStem for certain other disease indications.

We have incurred losses since inception of operations in December 1995 and had an accumulated deficit
of $160.5 million at December 31, 2007. Our losses have resulted principally from costs incurred in research
and development, clinical and preclinical product development, acquisition and licensing costs, and general
and administrative costs associated with its operations. Athersys has used the financing proceeds from private
equity and debt offerings and other sources of capital to develop its technologies, such as RAGE, and to
acquire its stem cell technology. We have also built drug development capabilities that have enabled us to
advance product candidates into clinical trials. We have established strategic collaborations that provide
revenues and capabilities to help to further advance our product candidates, and we have also built a
substantial portfolio of intellectual property.

In connection with the merger in June 2007, Athersys negotiated with holders of its convertible preferred

stock a planned restructuring of its capital stock, which included the conversion of the preferred stock into
shares of its common stock, the termination of warrants issued to the former holders of Class C Convertible
Preferred Stock, and the elimination of accrued dividends payable to the former holders of Class C Convertible
Preferred Stock. As a result, immediately prior to the consummation of the merger with BTHC VI, all
convertible preferred stock (including termination of warrants and elimination of accrued dividends) was
converted into 53,341,747 shares of common stock. The change to the conversion ratios of the convertible
preferred stock was deemed to be an induced conversion, which resulted in a $4.8 million deemed dividend

37

and an increase to the net loss attributable to common stockholders in June 2007. Upon the closing of the
merger, the 53,341,747 shares of common stock were exchanged for 1,912,356 shares of BTHC VI common
stock using the merger exchange ratio. Athersys also retired all shares of stock held in treasury.

At the time the merger was effective, each share of common stock of Athersys was exchanged into

0.0358493 shares of BTHC VI common stock, par value $0.001 per share. Prior to the merger, BTHC VI
effected a 1-for-1.67 reverse stock split of its shares of common stock and increased the number of authorized
shares of common stock to 100,000,000.

BTHC VI’s acquisition of Athersys effected a change in control and was accounted for as a reverse

acquisition whereby Athersys is the accounting acquirer for financial statement purposes. Accordingly, the
financial statements presented reflect the historical results of Athersys and do not include the historical
financial results of BTHC VI prior to the consummation of the merger. Athersys’ authorized and issued shares
of common and preferred stock have been retroactively restated for all periods presented to reflect the merger
exchange ratio of 0.0358493. Basic and diluted net loss per share attributable to common stockholders have
been computed using the retroactively restated common stock.

On June 8, 2007, we completed the offering of 13,000,000 shares of our common stock and received
gross proceeds of $65.0 million. Investors in the June offering also received five-year warrants to purchase an
aggregate of 3,250,000 shares of common stock with an exercise price of $6.00 per share. The lead investor in
the June offering, Radius Venture Partners, invested $10.0 million and received additional five-year warrants to
purchase an aggregate of 500,000 shares of common stock with a cash or cashless exercise price of $6.00 per
share. The placement agents received cash fees in an amount equal to approximately $5.5 million, which was
based on 8.5% of the gross proceeds, excluding proceeds from existing investors. The placement agents also
received five-year warrants to purchase an aggregate of 1,093,525 shares of common stock with a cash or
cashless exercise price of $6.00 per share. In consideration for certain advisory services, we paid an affiliate of
BTHC VI’s then-largest stockholder a one-time fee of $350,000 in cash upon consummation of the merger.

Upon the closing of the June offering, the $10.0 million aggregate principal amount of convertible notes

issued to Angiotech were converted along with accrued interest into 1,885,890 shares of common stock at a
conversion price of $5.50 per share, which was 110% of the price per share in the June offering, in accordance
with the terms of the notes.

Upon the closing of the June offering, the notes issued to bridge investors were converted along with
accrued interest into 531,781 shares of common stock at a conversion price of $5.00 per share, which was the
price per share in the June offering. The bridge investors also exercised their $0.01 warrants upon the
conversion of the convertible preferred stock in connection with the merger for 999,977 shares of common
stock at an aggregate exercise price of $10,000. Upon the conversion of the bridge notes, the bridge investors
also received five-year warrants to purchase 132,945 shares of common stock at $6.00 per share, which terms
were consistent with the warrants issued to new investors in the June offering.

In May 2007, Athersys terminated the majority of stock option awards to its officers, employees, directors
and consultants. Only a nominal number of option awards (5,052 option shares) held by former employees and
consultants were assumed by us. Upon closing the merger, options for 3,625,000 shares of common stock were
issued under our equity incentive plans to employees, directors and consultants with an exercise price of $5.00
per share. For the year ended December 31, 2007, stock compensation expense was approximately $5.1 million,
of which $2.5 million was recorded as research and development expense and $2.6 million was recorded as
general and administrative expense. At December 31, 2007, total unrecognized compensation cost related to
unvested stock options was approximately $5.0 million, which is expected to be recognized by December 31,
2011 using the straight-line method.

Also in May 2007, Athersys sold certain non-core technology related to its asthma discovery program to

Wyeth Pharmaceuticals for $2.0 million.

In July 2007, we initiated a Phase I clinical trial for ATHX-105 in the United Kingdom. The primary
objective of the Phase I clinical trial was to assess the short-term safety of ATHX-105 and to establish an
appropriate dose range for subsequent clinical studies that will be conducted in order to assess safety and

38

effectiveness. The Phase I clinical trial, which included 107 subjects, was completed in January 2008. There
were no severe or serious adverse events observed in the clinical trial, no negative effects on cardiovascular,
hematology or other clinical parameters, and no discontinuations due to adverse events. Following a detailed
analysis of the results of the clinical trial, the completion of certain required non-clinical studies and
regulatory approval, we intend to initiate a Phase II clinical trial in the United States that will examine safety
and effectiveness in clinically obese patients.

In addition, applying our MultiStem platform, we have established therapeutic product development

programs in the areas of cardiovascular disease, HSC transplant support and ischemic stroke. We intend to
advance two or more MultiStem programs into clinical development in 2008.

Results of Operations

Since Athersys’ inception, its revenues have consisted of license fees from its collaborators and grant
proceeds from federal and state grants. Athersys has derived no revenue on the sale of FDA-approved products
to date. Research and development expenses consist primarily of costs associated with external clinical and
preclinical study fees, manufacturing costs, salaries and related personnel costs, legal expenses resulting from
intellectual property application processes, and laboratory supply and reagent costs. Athersys expenses research
and development costs as they are incurred. We expect to continue to make significant investments in research
and development to enhance our technologies, advance clinical trials of our product candidates, expand our
regulatory affairs and product development capabilities, conduct preclinical studies of our products and
manufacture our products. General and administrative expenses consist primarily of salaries and related
personnel costs, professional fees and other corporate expenses. Our expenses are expected to increase as we
expand our business development activities and support our operating activities. To date, Athersys has financed
its operations through private equity and debt financing and investments by strategic collaborators. We expect
to continue to incur substantial losses through at least the next several years.

The following table sets forth Athersys’ revenues and expenses for the periods indicated. The following

tables are stated in thousands.

Revenues

License fees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1,433
1,827
Grant revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$1,908
1,817

$ 763
2,833

$3,260

$3,725

$3,596

Year Ended December 31,
2006

2005

2007

Research and development expenses

Type of Expense

Year Ended December 31,
2006

2005

2007

Personnel costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Research supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clinical and preclinical development costs . . . . . . . . . . . . . . . . . . . .
Sponsored research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Patent legal fees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 2,813
679
762
5,723
465
1,086
1,821
2,468

$2,721
1,208
879
2,702
579
595
781
276

$ 4,587
2,286
1,127
966
1,129
714
968
801

$15,817

$9,741

$12,578

39

General and administrative expenses

Type of Expense

Year Ended December 31,
2006

2005

2007

Personnel costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1,987
330
Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1,165
Legal and professional fees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1,822
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2,671
Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$1,891
291
590
392
183

$1,858
286
446
508
657

$7,975

$3,347

$3,755

Year Ended December 31, 2007 Compared to Years Ended December 31, 2006

Revenues. Revenues decreased to $3.3 million for the year ended December 31, 2007 from $3.7 million
for 2006. License fee revenues decreased $0.5 million as a result of the nature and timing of target acceptances
under our collaboration agreement with Bristol-Myers Squibb and Pfizer. Grant revenue remained consistent at
$1.8 million for each of 2007 and 2006. We expect our revenues from license fees and grants to continue at
similar levels in 2008.

Research and Development Expenses. Research and development expenses increased to $15.8 million in
2007 from $9.7 million in 2006. The increase of approximately $6.1 million related primarily to an increase in
clinical and preclinical development costs of $3.0 million, an increase in stock compensation expense of
$2.2 million, an increase in other expenses of $1.0 million and an increase in patent legal fees of $0.5 million
in 2007 compared to 2006. These increases were partially offset by a decrease in research supplies expenses of
$529,000, a decrease in sponsored research of $114,000 and a decrease in facilities costs of $117,000 in 2007
compared to 2006. The $3.0 million increase in preclinical and clinical costs is a result of the initiation of the
ATHX-105 clinical trial, performance of ATHX-105 non-clinical studies, and increases in MultiStem preclin-
ical and clinical costs and manufacturing expenses. We expect these expenses to continue to increase in 2008
as we expect to initiate our ATHX-105 Phase II clinical trial and two or more MultiStem clinical trials.
Included in other expenses for 2007 were two milestone payments totaling $1.0 million in cash and stock
associated with a collaboration milestone and an IND milestone related to our stem cell technology paid to the
former owners of the technology. In 2006, other expenses included a milestone payment of $125,000 paid in
stock related to a patent milestone covering the stem cell technology. These were the final milestone payments
to be made by us under the agreement governing the acquisition of the stem cell technology. The increase in
patent legal fees for 2007 was a result of maintaining our growing and maturing portfolio of patent
applications and the performance of patent legal work related to the May 2007 asthma asset sale. We
anticipate consistent levels of patent legal expense in 2008. Included in personnel costs for 2007 and 2006 was
approximately $447,000 and $121,000, respectively, of bonus payments related to the achievement of certain
milestones. We do not track our research expenses by project; rather, we track such expenses by the type of
cost incurred.

General and Administrative Expenses. General and administrative expenses increased to $8.0 million in
2007 from $3.3 million in 2006. The increase was due primarily to an increase in stock compensation expense
of $2.5 million, an increase in other expenses of $1.4 million, an increase in legal and professional fees of
$575,000 and an increase in personnel and facilities costs of $135,000. Included in other expenses for 2007
was a one-time advisory fee of $350,000 related to the merger, an allowance against a loan receivable in the
amount of $193,000, and $1.3 million of other general and administrative costs such as printing costs for SEC
filings, Nasdaq listing fees, directors’ and officers’ insurance costs, investor and public relations costs,
recruiting costs and costs related to compliance with Section 404 of the Sarbanes-Oxley Act of 2002. Included
in personnel costs for 2007 and 2006 was approximately $475,000 and $89,000, respectively, of bonus
payments related to the achievement of certain milestones. Also included in personnel costs in May 2006 was
approximately $122,000 ($146,000 including tax) in connection with the forgiveness of a 2002 loan made to
our Chief Executive Officer. The increase in legal and professional fees in 2007 was primarily a result of legal

40

fees incurred in connection with SEC filings, accounting and auditing fees incurred in connection with SEC
filings and fees for our board of directors. We expect our general and administrative expenses to continue at
similar levels in 2008.

Depreciation. Depreciation expense decreased to $283,000 in 2007 from $528,000 in 2006. The
decrease in depreciation expense was due to more laboratory equipment, computer equipment, furniture and
leasehold improvements becoming fully depreciated.

Other Income and Equity in Earnings of Unconsolidated Affiliate.

In May 2007, Athersys sold certain

non-core technology related to its asthma discovery program to Wyeth Pharmaceuticals for $2.0 million. In
January 2006, a milestone was achieved related to Athersys’ joint venture with Oculus. As a result, Athersys
received $100,000 of stock-based proceeds from Oculus, which was recorded in other income. Similarly,
Oculus also received stock-based proceeds in another company in the amount of $260,000. Athersys recorded
its share of Oculus’ net income (after recapturing past net losses) of $117,000 in equity in earnings of
unconsolidated affiliate in 2006.

Interest Income.

Interest income increased to $1.6 million in 2007 from $119,000 in 2006. The change

in interest income was due to the receipt and investment of the proceeds from the equity offering in June
2007. Due to declining interest rates and lower cash balances as a result of our ongoing and planned clinical
and preclinical development, we expect our 2008 interest income to be less than 2007.

Interest Expense.

Interest expense on Athersys’ debt outstanding under its senior loan and its subordi-

nated convertible promissory notes increased to $1.3 million for 2007 from $1.0 million in 2006. The increase
in interest expense was due to the $2.5 million in aggregate principal amount of subordinated convertible
promissory notes issued by Athersys to its bridge investors in October 2006, and the $10 million in aggregate
principal amount of subordinated convertible promissory notes issued to Angiotech in 2006 and 2007. These
convertible promissory notes were converted in the equity offering in June 2007. We expect our interest
expense to decrease for 2008 compared to 2007 as a result of the conversion of these promissory notes and
our repayment of our Senior Loan in June 2008, unless we issue new debt.

Accretion of Premium on Convertible Debt. The accretion of premium on convertible debt increased to

$0.5 million in 2007 from $0.3 million in 2006. The accretion relates to the $2.5 million in aggregate principal
amount of subordinated secured convertible promissory notes issued to bridge investors in October 2006. The
notes, if not converted, were repayable with accrued interest at maturity, plus a repayment fee of 200% of the
outstanding principal. Athersys computed a premium on the debt in the amount of $5.25 million due upon
redemption, which was being accreted over the term of the notes using the effective interest method. The
unamortized premium was reversed and recorded in additional paid-in-capital when the notes were converted
into common stock upon the closing of the equity offering in June 2007.

Year Ended December 31, 2006 Compared to Year Ended December 31, 2005

Revenues. Revenues increased to $3.7 million for the year ended December 31, 2006 from $3.6 million
for the comparable period in 2005. License fee revenues increased $1.1 million over this period as a result of
the nature and timing of target acceptances under Athersys’ collaboration agreement with Bristol-Myers
Squibb. Grant revenue decreased $1.0 million for the year ended December 31, 2006 compared to the year
ended December 31, 2005. In July 2003, Athersys was awarded a $5.0 million state grant that spanned three
years and was completed in February 2006. This grant was renewed in May 2006 for approximately
$3.5 million that will also span three years. The decrease in grant revenue for the year ended December 31,
2006 is principally the result of recognizing eight months of revenue under this state grant in 2006 versus
twelve months of revenue in 2005. In addition, Athersys had fewer active NIH grant awards in 2006 as
compared to 2005.

Research and Development Expenses. Research and development expenses decreased to $9.7 million in

2006 from $12.6 million in 2005. The decrease of approximately $2.9 million in research and development
expenses relates primarily to a decrease in personnel costs of $1.9 million, a decrease in research supplies
expenses of $1.1 million, a decrease in sponsored research of $550,000 and a decrease in facilities and other

41

costs of $435,000 related to the restructuring and reduction in force that occurred late in 2005. In addition,
patent legal fees decreased $119,000 and stock compensation expense decreased $525,000 in 2006 compared
to 2005. These decreases were partially offset by an increase in preclinical and clinical expenses of $1.7 million
in 2006 compared to 2005. As Athersys has evolved from a research-oriented company to a product-oriented
company, its staffing needs have evolved, resulting in the reductions in personnel and related costs. Athersys
has been optimizing the mix of its internal capabilities with the capabilities of its outside collaborators,
academic institutions, and third-party contract research organizations resulting in an increase in these costs.

General and Administrative Expenses. General and administrative expenses decreased to $3.3 million in

2006 from approximately $3.8 million in 2005. The decrease in general and administrative expenses was due
primarily to a decrease in stock compensation expense of $474,000 and a decrease in other expenses of
$116,000. These decreases were offset by an increase in legal and professional fees of $144,000, which was a
result of legal costs associated with potential financing and strategic transactions.

Depreciation. Depreciation expense decreased to $528,000 in 2006 from $982,000 in 2005. The
decrease in depreciation expense was due to more laboratory equipment, computer equipment, furniture, and
leasehold improvements becoming fully depreciated, combined with fewer purchases of new equipment.

Restructuring Costs. Restructuring costs for the year ended December 31, 2005 were a result of the

restructuring and reduction in force, which occurred late in 2005.

Other Income and Equity in Earnings of Unconsolidated Affiliate.

In January 2006, a milestone was
achieved related to Athersys’ joint venture with Oculus. As a result, Athersys received $100,000 of stock-
based proceeds from Oculus, which was recorded in other income. Similarly, Oculus also received stock-based
proceeds in another company in the amount of $260,000. Athersys recorded its share of Oculus’ net income
(after recapturing past net losses) of $117,000 in equity in earnings of unconsolidated affiliate on the statement
of operations.

Interest Income.

Interest income decreased to $119,000 for the year ended December 31, 2006 from
$317,000 in 2005. Changes in interest income were due to changes in Athersys’ average cash balances and
available-for-sale securities during those years.

Interest Expense.

Interest expense on Athersys’ debt outstanding under its senior loan and its subordi-

nated convertible promissory notes increased to $1,047,000 for the year ended December 31, 2006 from
$964,000 for the comparable period in 2005. The increase in interest expense is due to the subordinated
convertible promissory notes issued by Athersys in May 2006 and October 2006.

Accretion of Premium on Convertible Debt. The accretion of premium on convertible debt for the year

ended December 31, 2006 was a result of the $2.5 million in aggregate principal amount of subordinated
secured convertible promissory notes issued in October 2006. The notes, if not converted, were repayable with
accrued interest at maturity, plus a repayment fee of 200% of the outstanding principal. Athersys has computed
a premium on the debt in the amount of $5.25 million due upon redemption, which is being accreted over the
term of the notes using the effective interest method. This accretion was reversed and recorded in additional
paid-in-capital in June 2007 when the notes were converted into common stock upon the closing of the equity
offering in June 2007.

Cumulative Effect of Change in Accounting Principle. Effective January 1, 2006, Athersys adopted the

fair value recognition provisions of SFAS No. 123(R) using the modified-prospective-transition method.
SFAS No. 123(R) requires Athersys to estimate forfeitures in calculating the expense relating to share-based
compensation, while previously Athersys was permitted to recognize forfeitures as an expense reduction upon
occurrence. The adjustment to apply estimated forfeitures to previously recognized share-based compensation
was accounted for as a cumulative effect of a change in accounting principle at January 1, 2006 and reduced
net loss by $306,000 for the year ended December 31, 2006.

42

Liquidity and Capital Resources

Our sources of liquidity include our cash balances and available-for-sale securities. At December 31,
2007, we had $13.2 million in cash and cash equivalents, and $36.3 million in available-for-sale securities.
Athersys has primarily financed its operations through private equity and debt financings that have resulted in
aggregate cumulative proceeds of approximately $200 million, which includes the gross proceeds of $65.0 mil-
lion received in the June 2007 offering.

We will require substantial additional funding in order to continue our research and product development

programs, including preclinical testing and clinical trials of our product candidates. We anticipate using
$23 million to $25 million in 2008, which is an increase in cash expenditures reflecting the impact of the
ATHX-105 Phase II clinical trial. With the anticipated completion of the ATHX-105 Phase II clinical trial, we
expect lower clinical development costs in 2009, and as a result, expect to have available cash to fund our
operations into 2010 based on our current business and operating plans and assuming no new financings. Our
funding requirements may change at any time due to technological advances or competition from other
companies. Our future capital requirements will also depend on numerous other factors, including scientific
progress in our research and development programs, additional personnel costs, progress in preclinical testing
and clinical trials, the time and cost related to proposed regulatory approvals, if any, and the costs in filing and
prosecuting patent applications and enforcing patent claims. We cannot assure you that adequate funding will
be available to us or, if available, that it will be available on acceptable terms. Any shortfall in funding could
result in our having to curtail our research and development efforts.

We expect to continue to incur substantial losses through at least the next several years and may incur

losses in subsequent periods. The amount and timing of our future losses are highly uncertain. Our ability to
achieve and thereafter sustain profitability will be dependent upon, among other things, successfully develop-
ing, commercializing and obtaining regulatory approval or clearances for our technologies and products
resulting from these technologies.

Net cash used in operating activities was $12.1 million, $8.4 million and $12.1 million in 2007, 2006 and

2005, respectively, and represented the use of cash in funding technology development and product develop-
ment initiatives. We expect that net cash used in operating activities will increase as we increase our clinical
trial activity for ATHX-105 and MultiStem and as we continue to advance our various research and product
development activities.

Net cash used in investing activities was $36.4 million in 2007. Net cash provided by investing activities
was $3.4 million and $10.3 million in 2006 and 2005, respectively. The fluctuations from period to period are
due to the timing of purchases and maturity dates of investments, and the purchase of equipment. Purchases of
equipment were $161,000, $83,000 and $239,000 in 2007, 2006 and 2005, respectively. We expect that our
capital equipment expenditures to continue at similar levels in 2008.

Financing activities provided cash of $60.2 million in 2007 and $5.4 million in 2006, and used cash of
$446,000 in 2005. These fluctuations relate primarily to proceeds from the equity offering in June 2007, the
issuance of convertible promissory notes in 2007 and 2006 to Angiotech and the bridge investors in 2006, and
repayments of our Senior Loan.

Investors in the equity offering in June 2007 also received five-year warrants to purchase an aggregate of

3,250,000 shares of common stock with an exercise price of $6.00 per share. The lead investor in the June
offering, Radius Venture Partners, invested $10.0 million in the June offering and received additional five-year
warrants to purchase an aggregate of 500,000 shares of common stock with a cash or cashless exercise price
of $6.00 per share. The placement agents for the June offering received five-year warrants to purchase an
aggregate of 1,093,525 shares of common stock with a cash or cashless exercise price of $6.00 per share.

Our Senior Loan will be repaid in full in June 2008, which had a balance of $1.8 million at December 31,
2007. The Senior Lenders have the right to receive a milestone payment of $2.25 million upon the occurrence
of certain events as clarified in the October 2007 amendment to the Senior Loan as follows: (1) the entire
amount upon (a) the merger with or into another entity where our stockholders do not hold at least a majority
of the voting power of the surviving entity, (b) the sale of all or substantially all of our assets, and (c) our

43

liquidation or dissolution; or (2) a portion of the amount from proceeds of equity financings not tied to
specific research and development activities that are part of a research or development collaboration. In this
case, the Senior Lenders will receive an amount equal to 10% of proceeds above $5.0 million in cumulative
gross proceeds until the milestone amount is paid in full. The milestone payment is payable in cash, except
that if the milestone event is (2) above, we may elect to pay 75% of the milestone in shares of common stock
at the per-share offering price. The Senior Lenders also received warrants to purchase 149,026 shares of
common stock with an exercise price of $5.00 upon the closing of the June offering.

In connection with developing MultiStem for the treatment of the cardiovascular disorders of myocardial

infarction and peripheral vascular disease as part of a commercial collaboration with Angiotech that was
entered into in May 2006, in support of the collaboration, Angiotech purchased subordinated convertible
promissory notes in the aggregate principal amount of $10.0 million, which were converted along with accrued
interest into common stock upon the closing of the June offering. We may also receive up to $3.75 million of
additional equity investments and $63.75 million of aggregate cash payments based upon the successful
achievement of specified clinical development and commercialization milestones, though there can be no
assurance that we will achieve any milestones.

Under the terms of the collaboration, the parties plan to jointly fund clinical development activity,

whereby preclinical costs will be borne solely by Athersys, costs for phase I and phase II studies will be borne
50% by Athersys and 50% by Angiotech, costs for the first phase III study will be borne 33% by Athersys and
67% by Angiotech, and costs for any phase III studies subsequent to the first phase III study will be borne
25% by Athersys and 75% by Angiotech. We will have lead responsibility for preclinical and early clinical
development and manufacturing of the MultiStem product, and Angiotech will take the lead on pivotal and
later clinical trials and commercialization. Late in 2007, the parties began to share costs for phase I clinical
development, of which $63,000 was due from Angiotech at December 31, 2007. We will receive nearly half of
the net profits from the sale of any jointly developed, approved products. In addition, we will retain the
commercial rights to MultiStem for all other therapeutic applications, including treatment of stroke, bone
marrow transplantation and oncology support, blood and immune system disorders, autoimmune disease, and
other indications that we may elect to pursue. In December 2007, we achieved a clinical development
milestone upon the authorization of our IND by the FDA. This milestone event required Angiotech to either
purchase $5.0 million of our common stock, or forego the purchase and allow us to select from two pre-
defined milestone replacements. Angiotech opted to forego the purchase, and we elected to increase our share
of the net profits from the sale of approved products as the replacement milestone.

Our contractual payment obligations as of December 31, 2007 are as follows:

Contractual Obligations

Total

Operating lease for facilities . . . . $ 741,000
Long-term debt (principal) . . . . . $1,800,000
Long-term debt (interest) . . . . . . . $
75,000
Research funding . . . . . . . . . . . . $1,327,000

Less Than
1 Year

$ 309,000
$1,800,000
$
75,000
$ 336,000

$ 432,000
—
—
$ 991,000

Total. . . . . . . . . . . . . . . . . . . . . . $3,943,000

$2,520,000

$1,423,000

—
—
—

—

—
—
—

—

1-3 Years

3-5 Years

More Than
5 Years

The amount of long-term debt on the balance sheet at December 31, 2007 is reflected net of a discount.
We have an operating lease for our office and laboratory space with options to renew through March 2013 at
the existing rental rate. We exercised options to renew the lease through March 2010. In 2008, we entered into
a three-year lease agreement for office and laboratory space for our Belgian subsidiary, with an annual rent of
approximately $45,000, subject to annual adjustments based on an inflationary index. The lease includes an
option to renew for four additional years, through December 31, 2014.

The research funding in the table above represents our funding commitment for research programs

conducted at KUL. Our agreement provides KUL with four years of research funding commencing in
September 2007 and requires our approval on annual research programs and budgets. We approved the first
year’s research program, but have included in the table above the minimum funding for the subsequent years,

44

which is denominated in Euros and has been converted into U.S. dollars using the December 31, 2007
exchange rate. KUL is entitled to an annual milestone payment related to the continued operation of the
research agreement, which is included in the table above, and may receive royalties on future net sales of
products developed using MAPC-related inventions. The research agreement may be terminated after two
years or upon material breach by either party. KUL may terminate the license if we fail to pay royalties when
due or upon material breach of the license terms.

We filed a resale registration statement with the SEC for 18,508,251 shares of common stock, which

includes all shares of common stock issued in the equity offering in June 2007 and shares of common stock
issuable upon exercise of the warrants issued in the offering (as well as the 531,781 shares of common stock
issued to the bridge investors and the 132,945 shares underlying their warrants). The resale registration
statement was declared effective by the SEC on October 18, 2007. Subject to certain exceptions, if the resale
registration statement ceases to remain effective, a 1% cash penalty will be assessed for each 30-day period
until the registration statement becomes effective again, capped at 10% of the aggregate gross proceeds we
received from the equity offering.

Athersys has never paid dividends on its capital stock, and all accrued cumulative dividends were

eliminated in June 2007 in connection with the merger.

We have no off-balance sheet arrangements.

Critical Accounting Policies and Management Estimates

The SEC defines critical accounting policies as those that are, in management’s view, important to the

portrayal of our financial condition and results of operations and demanding of management’s judgment. Our
discussion and analysis of financial condition and results of operation are based on Athersys’ consolidated
financial statements, which have been prepared in accordance with U.S. generally accepted accounting
principles, or GAAP. The preparation of these financial statements requires us to make estimates on experience
and on various assumptions that we believe are reasonable under the circumstances, the results of which form
the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent
from other sources. Actual results may differ from those estimates.

Our critical accounting polices include:

Revenue Recognition

Our revenue recognition policies are in accordance with the SEC Staff Accounting Bulletin No. 104,
Revenue Recognition, and Emerging Issues Task Force No. 00-21, “Revenue Arrangements with Multiple
Deliverables,” which provide guidance on revenue recognition in financial statements and are based on the
interpretations and practices developed by the SEC. Our license and collaboration agreements contain multiple
elements, including technology access and development fees, cost-sharing, milestones and royalties.

Revenue from transactions that do not require future performance obligations from us is recognized when

performance is complete and when collectability is reasonably assured. Our license fee revenue primarily
consists of fees received from a collaborator, which are specifically set forth in the license and collaboration
agreement as amounts due to us based on our completion of certain tasks (e.g., delivery and acceptance of a
cell line). Upon acceptance by the collaborator of a cell line for use in its own product development efforts,
we have no further performance obligations with respect to the cell line or products developed using the cell
line. In addition, we receive specified payments upon the collaborator’s achievement of certain developmental
milestones (e.g., clinical trial phases), which is recognized when the milestone is achieved by our collaborator.

Revenue from grants consists primarily of funding under cost reimbursement programs from federal and

state sources for qualified research and development activities performed by us. Revenue from grants is
recorded when earned under the terms of the agreements.

45

Collaborative Arrangements

Collaborative arrangements that involve cost or future profit sharing are reviewed to determine the nature
of the arrangement and the nature of the collaborative parties’ businesses. The arrangements are also reviewed
to determine if one party has sole or primary responsibility for an activity, or whether the parties have shared
responsibility for the activity. If responsibility for an activity is shared and there is no principal party, then the
related costs of that activity are recognized by us on a net basis in the statement of operations (e.g., total cost,
less reimbursement from collaborator). If we are deemed to be the principal party for an activity, then the
costs and revenues associated with that activity are recognized on a gross basis in the statement of operations.

Clinical Trial Costs

Clinical trial costs are accrued based on work performed by outside contractors who manage and perform

the trials. We obtain estimates of total costs based on enrollment of subjects, completion of studies and other
events. Accrued clinical trial costs are subject to revisions as clinical trials progress, and any revisions are
recorded in the period in which the facts that give rise to the revisions become known.

Investments in Available-for-Sale Securities

We determine the appropriate classification of investment securities at the time of purchase and re-

evaluate such designation as of each balance sheet date. Our investments typically consist primarily of
U.S. government obligations, corporate debt securities, floating rate notes and commercial paper, all of which
are classified as available-for-sale. Available-for-sale securities are carried at fair value, with the unrealized
gains and losses, net of tax, reported as a component of accumulated other comprehensive income. The
amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to
maturity. Such amortization or accretion is included in interest income. Realized gains and losses on available-
for-sale securities are included in interest income. The cost of securities sold is based on the specific
identification method. Interest earned on securities classified as available-for-sale is included in interest
income.

Stock-Based Compensation

Effective January 1, 2006, we adopted the fair value recognition provisions of SFAS No. 123(R) using the

modified-prospective-transition method. Under that transition method, compensation cost recognized since
January 1, 2006 included: (a) compensation cost for all share-based payments granted prior to, but not yet
vested, as of January 1, 2006, based on the grant date fair value estimated in accordance with the original
provisions of SFAS No. 123, and (b) compensation cost for all share-based payments granted subsequent to
January 1, 2006, based on the grant-date fair value estimated in accordance with the provisions of
SFAS No. 123(R). For some of the awards granted prior to the adoption of SFAS No. 123(R), we recognized
compensation expense on the accelerated method using graded vesting. For awards granted subsequent to
adoption of SFAS No. 123(R), we recognize expense on the straight-line method.

We use a Black-Scholes option pricing model to estimate the grant-date fair value of share-based awards
under SFAS No. 123(R). The expected term of options granted represent the period of time that option grants
are expected to be outstanding. We use the “simplified” method under SEC Staff Accounting Bulletin No. 110
to calculate the expected life of option grants in 2007 given our limited history. We determine volatility by
using the historical stock volatility of other companies with similar characteristics. Estimates of fair value are
not intended to predict actual future events or the value ultimately realized by persons who receive equity
awards.

SFAS No. 123(R) requires forfeitures to be estimated at the time of grant and revised, if necessary, in
subsequent periods if actual forfeitures differ from those estimates. If actual forfeitures vary from the estimate,
we will recognize the difference in compensation expense in the period the actual forfeitures occur or when
options vest. Prior to the adoption of SFAS No. 123(R), we were permitted to recognize forfeitures as an
expense reduction upon occurrence. The adjustment to apply estimated forfeitures to previously recognized

46

share-based compensation was accounted for as a cumulative effect of a change in accounting principle at
January 1, 2006, and reduced net loss by $305,587 for the year ended December 31, 2006.

Recently Issued Accounting Standards

In September 2006, the FASB issued SFAS No. 157, Fair Value Measurements, or SFAS No. 157, which
creates a framework for measuring fair value, clarifies the definition of fair value and expands the disclosures
regarding fair value measurements. SFAS No. 157 does not require any new fair value measurements and is
effective for fiscal years beginning after November 15, 2007, thus January 1, 2008. We adopted the new
standard as of the effective date and currently do not believe the adoption will have a material impact on our
financial position or future results as we are already performing our investment valuation calculations and
estimating the fair value of our financial instruments using methodology which is principally consistent with
SFAS No. 157. We will continue to study the impact that SFAS No. 157 will have on future disclosures of the
fair values of our nonfinancial assets and liabilities.

CAUTIONARY NOTE ON FORWARD-LOOKING STATEMENTS

This annual report on Form 10-K contains forward-looking statements within the meaning of the Private

Securities Litigation Reform Act of 1995 that involve risks and uncertainties. These forward-looking statements
relate to, among other things, the expected timetable for development of our product candidates, our growth
strategy, and our future financial performance, including our operations, economic performance, financial
condition, prospects, and other future events. We have attempted to identify forward-looking statements by
using such words as “anticipates,” “believes,” “can,” “continue,” “could,” “estimates,” “expects,” “intends,”
“may,” “plans,” “potential,” “should,” “will,” or other similar expressions. These forward-looking statements
are only predictions and are largely based on our current expectations. These forward-looking statements
appear in a number of places in this annual report.

In addition, a number of known and unknown risks, uncertainties, and other factors could affect the

accuracy of these statements. Some of the more significant known risks that we face are the risks and
uncertainties inherent in the process of discovering, developing, and commercializing products that are safe
and effective for use as human therapeutics, including the uncertainty regarding market acceptance of our
product candidates and our ability to generate revenues. The following risks and uncertainties may cause our
actual results, levels of activity, performance, or achievements to differ materially from any future results,
levels of activity, performance, or achievements expressed or implied by these forward-looking statements:

(cid:129) our ability to successfully complete clinical trials for our product candidates;

(cid:129) the possibility of delays in, adverse results of, and excessive costs of the development process;

(cid:129) changes in external market factors;

(cid:129) changes in our industry’s overall performance;

(cid:129) changes in our business strategy;

(cid:129) our ability to protect our intellectual property portfolio;

(cid:129) our possible inability to enter into licensing or co-development arrangements for certain product

candidates;

(cid:129) our possible inability to execute our strategy due to changes in our industry or the economy generally;

(cid:129) changes in productivity and reliability of suppliers;

(cid:129) the success of our competitors and the emergence of new competitors; and

(cid:129) the risks mentioned elsewhere in this annual report under Item 1A, “Risk Factors.”

Although we currently believe that the expectations reflected in the forward-looking statements are

reasonable, we cannot guarantee our future results, levels of activity or performance. We undertake no

47

obligation to publicly update forward-looking statements, whether as a result of new information, future events
or otherwise, except as otherwise required by law. You are advised, however, to consult any further disclosures
we make on related subjects in our reports on Forms 10-Q, 8-K and 10-K furnished to the SEC. You should
understand that it is not possible to predict or identify all risk factors. Consequently, you should not consider
any such list to be a complete set of all potential risks or uncertainties.

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Interest Rate Risk

Our exposure to interest rate risk is related to our investment portfolio and our borrowings. Fixed rate
investments and borrowings may have their fair market value adversely impacted from changes in interest
rates. Due in part to these factors, our future investment income may fall short of expectations. Further, we
may suffer losses in investment principal if we are forced to sell securities that have declined in market value
due to changes in interest rates. We invest our excess cash primarily in debt instruments of the U.S. government
and its agencies, corporate debt securities, floating-rate notes and A1+/P1 commercial paper.

We enter into loan arrangements with financial institutions when needed. At December 31, 2007, we had
borrowings of approximately $1.8 million million outstanding under our Senior Loan, which bears interest at a
fixed rate of approximately 13%.

48

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

Athersys, Inc.

Consolidated Financial Statements

Years Ended December 31, 2007, 2006 and 2005

Contents

Reports of Independent Registered Public Accounting Firm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Balance Sheets as of December 31, 2007 and 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Operations for each of the years ended December 31, 2007, 2006 and 2005 . .
Consolidated Statements of Stockholders’ Equity (Deficit) for each of the years ended December 31,

2007, 2006 and 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Consolidated Statements of Cash Flows for each of the years ended December 31, 2007, 2006 and 2005. .
Notes to Consolidated Financial Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

50
52
53

54
55
56

49

Report of Independent Registered Public Accounting Firm

The Board of Directors and Stockholders
Athersys, Inc.

We have audited the accompanying consolidated balance sheets of Athersys, Inc. as of December 31,
2007 and 2006, and the related consolidated statements of operations, stockholders’ equity (deficit) and cash
flows for each of the three years in the period ended December 31, 2007. Our audits also included the
financial statement schedule listed in the Index at Item 15(a)(2). These financial statements and schedule are
the responsibility of the Company’s management. Our responsibility is to express an opinion on these financial
statements and schedule based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight

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

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

respects, the consolidated financial position of Athersys, Inc. at December 31, 2007 and 2006, and the
consolidated results of its operations and its cash flows for each of the three years in the period ended
December 31, 2007, in conformity with U.S. generally accepted accounting principles. Also, in our opinion,
the related financial statement schedule, when considered in relation to the basic financial statements taken as
a whole, presents fairly in all material respects the information set forth therein.

As discussed in Note B to the consolidated financial statements, the Company adopted the provisions of

Statement of Financial Accounting Standards No. 123(R), Share-Based Payment, effective January 1, 2006.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight
Board (United States), Athersys, Inc.’s internal control over financial reporting as of December 31, 2007, based
on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring
Organizations of the Treadway Commission and our report dated March 14, 2008 expressed an unqualified
opinion thereon.

Cleveland, Ohio
March 14, 2008

50

Report of Independent Registered Public Accounting Firm

The Board of Directors and Stockholders
Athersys, Inc.

We have audited Athersys, Inc.’s internal control over financial reporting as of December 31, 2007, based

on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring
Organizations of the Treadway Commission (the COSO criteria). Athersys, Inc.’s management is responsible
for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of
internal control over financial reporting included in the accompanying Management’s Report on Internal
Control over Financial Reporting, which is included in Item 9A. Our responsibility is to express an opinion on
the company’s internal control over financial reporting based on our audit.

We conducted our audit in accordance with the standards of the Public Company Accounting Oversight

Board (United States). Those standards require that we plan and perform the audit to obtain reasonable
assurance about whether effective internal control over financial reporting was maintained in all material
respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing
the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of
internal control based on the assessed risk, and performing such other procedures as we considered necessary
in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

A company’s internal control over financial reporting is a process designed to provide reasonable

assurance regarding the reliability of financial reporting and the preparation of financial statements for external
purposes in accordance with generally accepted accounting principles. A company’s internal control over
financial reporting includes those policies and procedures that: (1) pertain to the maintenance of records that,
in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company;
(2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial
statements in accordance with generally accepted accounting principles, and that receipts and expenditures of
the company are being made only in accordance with authorizations of management and directors of the
company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized
acquisition, use, or disposition of the company’s assets that could have a material effect on the financial
statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect
misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that
controls may become inadequate because of changes in conditions, or that the degree of compliance with the
policies or procedures may deteriorate.

In our opinion, Athersys, Inc. maintained, in all material aspects, effective internal control over financial

reporting as of December 31, 2007, based on the COSO criteria.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight
Board (United States), the consolidated balance sheets of Athersys, Inc. as of December 31, 2007 and 2006
and the related consolidated statements of operations, stockholders’ equity (deficit) and cash flows for each of
the three years in the period ended December 31, 2007 and our report dated March 14, 2008 expressed an
unqualified opinion thereon.

Cleveland, Ohio
March 14, 2008

51

Athersys, Inc.

Consolidated Balance Sheets

December 31,

2007

2006

(In thousands, except
share and per share
amounts)

ASSETS

Current assets:

Cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 13,248 $
Available-for-sale securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts receivable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Receivable from Angiotech . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Investment interest receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deposit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses and other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total current assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Available-for-sale securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deposit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Notes receivable, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts receivable, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equity investments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 52,225 $

22,477
836
63
262
163
394
37,443
13,850
100
86
387
42
317

LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)

Current liabilities:

Accounts payable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $
Accrued compensation and related benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued clinical trial costs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued expenses and other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current portion of long-term debt, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total current liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Long-term debt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Convertible promissory notes, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accrued dividends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stockholders’ equity (deficit):

Convertible preferred stock, at stated value; no shares authorized at December 31,
2007; 481,540 shares authorized, 364,524 shares issued and outstanding with an
aggregate liquidation preference of $68,187 at December 31, 2006; . . . . . . . . . . . .

Preferred stock, at stated value; 10,000,000 shares authorized, and no shares issued

and outstanding at December 31, 2007 and December 31, 2006. . . . . . . . . . . . . . .

Common stock, $0.001 par value; 100,000,000 shares authorized, 18,927,988 shares

1,011 $
71
735
993
1,784
4,594
—
—
—
—

1,528
—
872
—
—
—
261
2,661
—
100
562
509
117
317
4,266

898
423
—
1,214
3,332
5,867
1,800
7,510
214
8,882

—

—

68,301

—

issued and outstanding at December 31, 2007; 1,433,972 shares authorized,
293,770 shares issued and outstanding at December 31, 2006; . . . . . . . . . . . . . . . .
Additional paid-in capital
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Treasury stock, at cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated other comprehensive income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulated deficit
Total stockholders’ equity (deficit). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total liabilities and stockholders’ equity (deficit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 52,225 $

19
208,039
—
52
(160,479)
47,631

—
53,495
(250)
—
(141,553)
(20,007)
4,266

See accompanying notes.

52

Athersys, Inc.

Consolidated Statements of Operations

Year Ended December 31,

2007

2006

2005

(In thousands, except share and per share
amounts)

Revenues
License fees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $
Grant revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Total revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Costs and expenses
Research and development (including stock compensation expense of

1,433
1,827

3,260

$ 1,908
1,817

3,725

$

763
2,833

3,596

$2,468, $276 and $801 in 2007, 2006 and 2005, respectively) . . . . . .

15,817

9,741

12,578

General and administrative (including stock compensation expense of

$2,671, $183 and $657 in 2007, 2006 and 2005, respectively) . . . . . .
Depreciation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restructuring costs (including stock compensation income of $128) . . .

7,975
283
—

3,347
528
—

3,755
982
251

Total costs and expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24,075

13,616

17,566

Loss from operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equity in earnings of unconsolidated affiliate . . . . . . . . . . . . . . . . . . . .
Interest income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interest expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accretion of premium on convertible debt . . . . . . . . . . . . . . . . . . . . . .

Loss before cumulative effect of change in accounting principle . . .
Cumulative effect of change in accounting principle . . . . . . . . . . . . . . .

(20,815)
2,017
—
1,591
(1,263)
(456)

(18,926)
—

(9,891)
91
117
119
(1,047)
(260)

(10,871)
306

(13,970)
18
—
317
(964)
—

(14,599)
—

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $

(18,926)

$ (10,565)

$ (14,599)

Preferred stock dividends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deemed dividend resulting from induced conversion of convertible

(659)

(1,408)

(2,253)

preferred stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(4,800)

—

—

Net loss attributable to common stockholders . . . . . . . . . . . . . . . . . . $

(24,385)

$ (11,973)

$ (16,852)

Basic and diluted net loss per common share attributable to

common stockholders

Loss before cumulative effect of change in accounting principle . . . . . . $
Cumulative effect of change in accounting principle . . . . . . . . . . . . . . .

(2.26)
—

$ (41.89)
1.05

$ (57.79)
—

Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $

(2.26)

$ (40.84)

$ (57.79)

Weighted average shares outstanding, basic and diluted. . . . . . . . . .

10,811,119

293,142

291,612

See accompanying notes.

53

Athersys, Inc.

Consolidated Statements of Stockholders’ Equity (Deficit)

Convertible
Preferred Stock

Common Stock

Number
of Shares

Stated
Value

Number
of Shares

Par
Value

Additional
Paid-in
Capital

Treasury
Stock

Accumulated
Other
Comprehensive
Income (Loss)

Unearned
Compensation
Common Stock
Options

Total
Stockholders’
Equity
(Deficit)

Accumulated
Deficit

(In thousands, except share amounts)

Balance at January 1, 2005 . . . . .
Issuance of common stock, net . .
Repurchase of common and

422,468 $ 68,301
—

—

292,257

$— $ 51,831
3

72 —

preferred stock. . . . . . . . . .

(57,944)

$(35)
—

$(2,557)
—

$(116,389)
—

Amortization of unearned

compensation . . . . . . . . . .

Forfeitures of common stock

options . . . . . . . . . . . . . .
Accrued dividends — Class C . .
Accrued dividends — Class E . .
Reversal of Class E accrued

preferred dividends . . . . . . .
Comprehensive Loss:

Net loss . . . . . . . . . . . . . . .
Unrealized gain on available for

sale securities . . . . . . . . . .

Total comprehensive loss . . . . .

Balance at December 31, 2005 . . .
Issuance of common stock . . . .
Issuance of common stock

warrant . . . . . . . . . . . . . .
Adoption of SFAS No. 123(R) . .
Stock-based compensation . . . .
Accrued dividends — Class C . .

Comprehensive Loss:

Net loss . . . . . . . . . . . . . . .
Unrealized gain on available for

sale securities . . . . . . . . . .

Total comprehensive loss . . . . .

Balance at December 31, 2006 . . .
Stock based compensation . . . .
Accrued dividends — Class C . .
Elimination of cumulative

accrued dividends — Class C. .

Conversion of preferred stock to

—

—

—
—
—

—

—

—

(1,388) —

— —

— —
— —
— —

—

—

(418)
(1,306)
(947)

— —

6,016

— —

— —

—

—

—

—
—
—

—

—

—

364,524
—

68,301
—

290,941 —
2,829 —

55,179
130

(250)
—

(17)
—

—
—
—
—

—

—

—
—
—
—

—

—

— —
— —
— —
— —

— —

— —

250
(809)
153
(1,408)

—

—

—
—
—
—

—

—

364,524
—
—

68,301
—
—

293,770 —
— —
— —

53,495
5,139
(659)

(250)
—
—

—

—

— —

9,541

common stock . . . . . . . . . .

(364,524)

(68,301) 1,912,356

2

68,299

Issuance of common stock from

warrant exercises . . . . . . . .
Retirement of treasury stock . . .
Shares of common stock for

Merger with BTHC VI, Inc. . .
Issuance of common stock, net of
expenses . . . . . . . . . . . . .

Issuance of common stock

warrants . . . . . . . . . . . . .

Issuance of common stock for
conversion of convertible
notes . . . . . . . . . . . . . . .
Comprehensive Loss:

Net loss . . . . . . . . . . . . . . .
Unrealized gain on available for

sale securities . . . . . . . . . .

Total comprehensive loss . . . . .

—
—

—

—

—

—

—

—

— 1,003,190
—

1
— —

9
(250)

—

299,622 —

— 13,001,379

13

58,479

—

— —

492

— 2,417,671

3

13,494

—

—

— —

— —

—

—

—
—
—

—

—

18

—
—
—
—

—

17

—
—
—

—

—

—
—

—

—

—

—

—

52

$ —
—

(250)

—

—
—
—

—

—

—

—

—

—
250

—

—

—

—

—

—

—

1,330

418
—
—

—

—

—

(809)
—

—
809
—
—

—

—

—
—
—

—

—

—
—

—

—

—

—

—

—

1,151
3

(250)

1,330

—
(1,306)
(947)

6,016

—

—

—
—
—

—

(14,599)

(14,599)

—

18

(130,988)
—

—
—
—
—

(14,581)

(8,584)
130

250
—
153
(1,408)

(10,565)

(10,565)

17

(10,548)

(20,007)
5,139
(659)

9,541

—

10
—

—

58,492

492

13,497

(141,553)
—
—

—

—

—
—

—

—

—

—

(18,926)

(18,926)

—

52

(18,874)

Balance at December 31, 2007. . .

— $

— 18,927,988

$19

$208,039

$ —

$ 52

$ —

$(160,479)

$ 47,631

See accompanying notes.

54

Athersys, Inc.

Consolidated Statements of Cash Flows

2007

Year Ended December 31,
2006
(In thousands)

2005

Operating activities
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $(18,926) $(10,565) $(14,599)
Adjustments to reconcile net loss to net cash used in operating activities:

Depreciation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fixed asset impairment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gain on sale of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equity in earnings of unconsolidated affiliate . . . . . . . . . . . . . . . . . . . . . .
Accretion of premium on convertible debt . . . . . . . . . . . . . . . . . . . . . . . . .
Provision/forgiveness of notes receivable . . . . . . . . . . . . . . . . . . . . . . . . . .
Earned milestone applied to note receivable . . . . . . . . . . . . . . . . . . . . . . .
Stock-based compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expense related to warrants issued to lenders. . . . . . . . . . . . . . . . . . . . . . .
Income from cumulative effect of change in accounting principle . . . . . . . .
Amortization of premium (discount) on available for sale securities and

283
—
—
—
456
193
283
5,139
476
—

528
—
—
(117)
260
122
—
459
—
(306)

982
87
(18)
—
—
—
—
1,330
—
—

other. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(52)

15

(44)

Changes in operating assets and liabilities:

Accounts receivable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Receivable from Angiotech . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prepaid expenses and other assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accounts payable and accrued expenses . . . . . . . . . . . . . . . . . . . . . . . .

111
(63)
(558)
592

(361)
—
21
1,546

22
—
10
112

Net cash used in operating activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Investing activities
Purchase of available for sale securities . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proceeds from maturities of available for sale securities . . . . . . . . . . . . . . . .
Proceeds from sale of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Purchases of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Net cash (used in) provided by investing activities . . . . . . . . . . . . . . . . . . . .
Financing activities
Principal payments on debt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proceeds from convertible promissory notes . . . . . . . . . . . . . . . . . . . . . . . . .
Repurchase of common and preferred stock held in treasury . . . . . . . . . . . . .
Proceeds from issuance of common stock, net . . . . . . . . . . . . . . . . . . . . . . . .

Net cash provided by (used in) financing activities . . . . . . . . . . . . . . . . . . . .

Increase (decrease) in cash and cash equivalents . . . . . . . . . . . . . . . . . . . . . .
Cash and cash equivalents at beginning of year . . . . . . . . . . . . . . . . . . . . . . .

(12,066)

(8,398)

(12,118)

(46,316)
10,100
—
(161)

(3,426)
6,932
—
(83)

(5,006)
15,563
23
(239)

(36,377)

3,423

10,341

(3,332)
5,000
—
58,495

60,163

11,720
1,528

(2,083)
7,500
—
6

5,423

448
1,080

(199)
—
(250)
3

(446)

(2,223)
3,303

Cash and cash equivalents at end of year. . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 13,248

$ 1,528 $ 1,080

See accompanying notes.

55

Athersys, Inc.

Notes to Consolidated Financial Statements

A. Background, Recent Merger and Offering

Athersys, Inc. (“Athersys” or the “Company”) is a biopharmaceutical company engaged in the discovery

and development of therapeutic products in one business segment. Operations consist primarily of research and
product development activities.

On June 8, 2007, Athersys’ subsidiary, which was then named Athersys, Inc. (“Old Athersys”), effected a
merger into a wholly-owned subsidiary of a public company (the “Merger”). The public company, BTHC VI,
Inc. (“BTHC VI”), was a shell corporation with no assets, liabilities or operations as of the date of the Merger,
and had 299,622 shares of common stock outstanding. Upon completion of the Merger, the officers and
directors of Old Athersys assumed control over the operations of BTHC VI, and Old Athersys’ operations
became the sole operations of BTHC VI on a consolidated basis. In August 2007, BTHC VI changed its name
to Athersys, Inc.

Prior to the consummation of the Merger, Old Athersys negotiated with holders of its convertible

preferred stock a planned restructuring of its capital stock, which included the conversion of its preferred stock
into shares of Old Athersys’ common stock, the termination of warrants issued to the former holders of Class C
Convertible Preferred Stock, and the elimination of accrued dividends payable to the former holders of Class C
Convertible Preferred Stock. As a result, immediately prior to the consummation of the Merger, all convertible
preferred stock (including termination of warrants and elimination of accrued dividends) was converted into
53,341,747 shares of common stock. The change to the conversion ratios of the convertible preferred stock
was deemed to be an induced conversion, which resulted in a $4.8 million deemed dividend and an increase to
the net loss attributable to common stockholders in June 2007. Upon the closing of the Merger, the
53,341,747 shares of Old Athersys common stock were exchanged for 1,912,356 shares of BTHC VI common
stock using the Merger exchange ratio. Old Athersys also retired all shares of stock held in treasury.

At the time the Merger was effective, each share of Old Athersys’ common stock was exchanged into
0.0358493 shares of BTHC VI common stock, par value $0.001 per share. Prior to the Merger, BTHC VI
effected a 1-for-1.67 reverse stock split of its shares of common stock and increased the number of authorized
shares of common stock to 100,000,000.

BTHC VI’s acquisition of Old Athersys effected a change in control and was accounted for as a reverse

acquisition whereby Old Athersys is the accounting acquirer for financial statement purposes. Accordingly, the
financial statements of the Company presented reflect the historical results of Old Athersys and do not include
the historical financial results of BTHC VI prior to the consummation of the Merger. The Company’s
authorized and issued shares of common and preferred stock have been retroactively restated for all periods
presented to reflect the Merger exchange rate of 0.0358493. Basic and diluted net loss per share attributable to
common stockholders has been computed using the retroactively restated common stock.

Immediately after the Merger, the Company completed an offering of 13,000,000 shares of common stock

for aggregate gross proceeds of $65,000,000 (the “Offering”). Offering costs in the amount of approximately
$6.5 million were netted against the proceeds of the Offering, resulting in net proceeds from the Offering of
approximately $58.5 million. The Offering included the issuance of warrants to purchase 3,250,000 shares of
common stock to the investors with an exercise price of $6.00 and a five-year term. The Company also issued
warrants to purchase 500,000 shares of common stock to the lead investor and warrants to purchase
1,093,525 shares of common stock to the placement agents, all with an exercise price of $6.00 and five-year
terms. The placement agents also received a cash fee in an amount equal to 8.5% of the gross proceeds, less
proceeds from existing investors in Old Athersys. In consideration for certain advisory services, Old Athersys
paid an affiliate and largest stockholder of BTHC VI a one-time fee of $350,000 in cash upon consummation
of the Merger.

Upon the closing of the Offering, the $10.0 million of convertible notes issued to Angiotech Pharmaceu-

ticals, Inc. (“Angiotech”) (see Note F) were converted along with accrued interest into 1,885,890 shares of

56

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

A. Background, Recent Merger and Offering — (Continued)

common stock at a conversion price of $5.50 per share, which was 110% of the price per share in the
Offering, in accordance with the terms of the notes.

Upon the closing of the Offering, the notes issued to bridge investors (see Note G) were converted along

with accrued interest into 531,781 shares of common stock at a conversion price of $5.00 per share, which
was the price per share in the Offering, in accordance with the terms of the bridge notes. The bridge investors
also exercised their $0.01 warrants upon the conversion of the convertible preferred stock in connection with
the Merger for 999,977 shares of common stock at an aggregate exercise price of $10,000. Upon the
conversion of the bridge notes, the bridge investors also received five-year warrants to purchase 132,945 shares
of common stock at $6.00 per share, which terms were consistent with the warrants issued to new investors in
the Offering.

The Company filed a resale registration statement with the SEC for 18,508,251 shares of common stock,
which includes all shares of common stock issued in the Offering and shares of common stock issuable upon
exercise of the warrants issued in the Offering (as well as the 531,781 shares of common stock issued to the
bridge investors and the 132,945 shares underlying their warrants). The resale registration statement was
declared effective by the SEC on October 18, 2007. Subject to certain exceptions, if the resale registration
statement ceases to remain effective, a 1% cash penalty will be assessed for each 30-day period until the
registration statement becomes effective again, capped at 10% of the aggregate gross proceeds received in the
Offering.

In 2007, Old Athersys sold certain non-core technology related to its asthma drug discovery program to a

pharmaceutical company for $2.0 million, which was recognized as a gain on the sale in other income in
2007.

B. Accounting Policies

Principles of Consolidation

The consolidated financial statements include the accounts and results of operations of the Company and
its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolida-
tion. Investments in joint ventures are accounted for using the equity method when the Company does not
control the investee, but has the ability to exercise significant influence over the investee’s operations and
financial policies.

Revenue Recognition

The Company’s revenue recognition policies are in accordance with the SEC Staff Accounting Bulletin
(“SAB”) No. 104, “Revenue Recognition,” and Emerging Issues Task Force (“EITF”) No. 00-21, “Revenue
Arrangements with Multiple Deliverables,” which provide guidance on revenue recognition in financial
statements and are based on the interpretations and practices developed by the SEC. The Company’s license
and collaboration agreements contain multiple elements, including technology access and development fees,
cost-sharing, milestones and royalties.

Revenue from transactions that do not require future performance obligations from the Company is
recognized when performance is complete and when collectability is reasonably assured. The Company’s
license fee revenue primarily consists of fees received from a collaborator, which are specifically set forth in
the license and collaboration agreement as amounts due to the Company based on its completion of certain
tasks (e.g., delivery and acceptance of a cell line). Upon acceptance by the collaborator of a cell line for use
in its own product development efforts, the Company has no further performance obligations with respect to
the cell line or products developed using the cell line. In addition, the Company receives specified payments

57

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

B. Accounting Policies — (Continued)

upon the collaborator’s achievement of certain developmental milestones (e.g., clinical trial phases), which are
recognized when the milestones are achieved by our collaborator.

Revenue from grants consists primarily of funding under cost reimbursement programs from federal and

state sources for qualified research and development activities performed by the Company. Revenue from
grants is recorded when earned under the terms of the agreements.

Cash and Cash Equivalents

The Company considers all highly liquid investments with a maturity of three months or less when

purchased to be cash equivalents. Cash equivalents are primarily invested in money market funds and
commercial paper. The carrying amount of the Company’s cash equivalents approximates fair value due to the
short maturity of the investments.

Research and Development

Research and development expenditures, which consist primarily of costs associated with external clinical

and preclinical study fees, manufacturing costs, salaries and related personnel costs, legal expenses resulting
from intellectual property application processes, and laboratory supply and reagent costs, including direct and
allocated overhead expenses, are charged to expense as incurred.

Collaborative Arrangements

Collaborative arrangements that involve cost or revenue sharing are reviewed to determine the nature of

the arrangement and the nature of the collaborative parties’ businesses. The arrangements are also reviewed to
determine if one party has sole or primary responsibility for an activity, or whether the parties have shared
responsibility for the activity. If responsibility for an activity is shared and there is no principal party, then the
related costs of that activity are recognized by the Company on a net basis in the statement of operations (e.g.,
total cost, less reimbursement from collaborator). If the Company is deemed to be the principal party for an
activity, then the costs and revenues associated with that activity are recognized on a gross basis in the
statement of operations.

Clinical Trial Costs

Clinical trial costs are accrued based on work performed by outside contractors, who manage and perform
the trials. The Company obtains estimates of total costs based on enrollment of subjects, completion of studies
and other events. Accrued clinical trial costs are subject to revisions as clinical trials progress, and any
revisions are recorded in the period in which the facts that give rise to the revisions become known.

Royalties

The Company may be required to remit royalty payments based on product sales to certain parties under
license agreements. The Company did not pay any royalties during the three-year period ended December 31,
2007.

Investments in Available-for-Sale Securities

Management determines the appropriate classification of investment securities at the time of purchase and

re-evaluates such designation as of each balance sheet date. The Company’s investments typically consist
primarily of U.S. government obligations, corporate debt securities, floating rate notes and commercial paper,
all of which are classified as available-for-sale. Available-for-sale securities are carried at fair value, with the

58

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

B. Accounting Policies — (Continued)

unrealized gains and losses, net of applicable tax, reported as a component of accumulated other comprehen-
sive income. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of
discounts to maturity. Such amortization or accretion is included in interest income. Realized gains and losses
on available-for-sale securities are included in interest income. The cost of securities sold is based on the
specific identification method. Interest earned on securities classified as available-for-sale is included in
interest income.

Long-Lived Assets

Equipment is stated at acquired cost less accumulated depreciation. Laboratory and office equipment are

depreciated on the straight-line basis over the estimated useful lives (three to seven years).

Long-lived assets are evaluated for impairment when events or changes in circumstances indicate that the

carrying amount of the asset or related group of assets may not be recoverable. If the expected future
undiscounted cash flows are less than the carrying amount of the asset, an impairment loss is recognized at
that time. Measurement of impairment may be based upon appraisal, market value of similar assets or
discounted cash flows. No impairment losses were recorded in 2007 or 2006. In connection with a
restructuring in 2005, the Company reduced the carrying value of certain laboratory equipment to its realizable
value, resulting in an impairment loss of $87,000.

Patent Costs and Rights

Costs of prosecuting and maintaining patents and patent rights are expensed as incurred. As of
December 31, 2007, the Company has filed for broad intellectual property protection on its proprietary
technologies. The Company currently has numerous U.S. patent applications and corresponding international
patent applications related to its technologies, as well as many issued U.S. and international patents.

Comprehensive Income (Loss)

Unrealized gains and losses on the Company’s available-for-sale securities are the only components of

accumulated other comprehensive income (loss). Total comprehensive income or loss is disclosed in the
consolidated statement of stockholders’ equity (deficit).

Concentration of Credit Risk

Accounts receivable are subject to concentration of credit risk due to the absence of a large number of
customers. At December 31, 2007 and 2006, one customer accounted for 51% and 78% of accounts receivable,
respectively. The Company does not require collateral from its customers.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the
United States requires management to make estimates and assumptions that affect the amounts reported in the
financial statements and accompanying notes. Actual results could differ from those estimates.

Stock-Based Compensation

Prior to the Company’s adoption of Statement of Financial Accounting Standard (“SFAS”)

No. 123(Revised 2004), Share-Based Payment (“SFAS No. 123(R)”), the Company accounted for its stock-
based compensation in accordance with the intrinsic value method as described in the provisions of
Accounting Principles Board Opinion No. 25, Accounting for Stock Issued to Employees, and related
interpretations, as permitted by SFAS No. 123, Accounting for Stock Based Compensation (“SFAS No. 123”).

59

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

B. Accounting Policies — (Continued)

As such, in 2005, compensation was measured on the date of issuance or grant as the excess of the current
estimated market value of the underlying stock over the exercise price of the stock option. Any unearned
compensation was recognized over the respective vesting periods of the equity instruments, if any, using the
graded vesting method as prescribed by Financial Accounting Standards Board (“FASB”) Interpretation No. 28.

Effective January 1, 2006, the Company adopted the fair value recognition provisions of SFAS No. 123(R),
using the modified-prospective-transition method. Under that transition method, compensation cost recognized
since January 1, 2006 included: (a) compensation cost for all share-based payments granted prior to, but not
yet vested, as of January 1, 2006, based on the grant date fair value estimated in accordance with the original
provisions of SFAS No. 123, and (b) compensation cost for all share-based payments granted subsequent to
January 1, 2006, based on the grant-date fair value estimated in accordance with the provisions of
SFAS No. 123(R). For some of the awards granted prior to the adoption of SFAS No. 123(R), the Company
recognized compensation expense using a grading vesting method. For awards granted subsequent to adoption
of SFAS No. 123(R), the Company recognizes expense on the straight-line method.

The Company uses a Black-Scholes option-pricing model to estimate the grant-date fair value of share-

based awards under SFAS No. 123(R). The expected term of options granted represent the period of time that
option grants are expected to be outstanding. The Company uses the “simplified” method under SAB No. 110
to calculate the expected life of option grants in 2007 given its limited history. The Company determines
volatility by using the historical stock volatility of other companies with similar characteristics.

SFAS No. 123(R) requires forfeitures to be estimated at the time of grant and revised, if necessary, in
subsequent periods if actual forfeitures differ from those estimates. If actual forfeitures vary from the estimate,
the Company will recognize the difference in compensation expense in the period the actual forfeitures occur
or when options vest. Prior to the adoption of SFAS No. 123(R), the Company was permitted to recognize
forfeitures as an expense reduction upon occurrence. The adjustment to apply estimated forfeitures to
previously recognized share-based compensation was accounted for as a cumulative effect of a change in
accounting principle at January 1, 2006, and reduced net loss by $305,587 for the year ended December 31,
2006

The following table illustrates the effect on net loss in 2005 if the Company had applied the fair value
recognition provisions of SFAS No. 123 to options granted under the Company’s stock option plans prior to
the adoption of SFAS No. 123(R). For purposes of this pro forma disclosure, the value of the options was
estimated using a Black-Scholes option-pricing formula and amortized to expense over the options’ vesting
periods (in thousands, except per share):

Year Ended
December 31,
2005

Net loss attributable to common stockholders:

As reported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total stock compensation expense included in net loss, as reported . . . . . . . . . . . . . .
Total stock compensation expense under the fair value method for all awards . . . . . .

$(16,852)
1,260
(2,312)

Pro forma net loss attributable to common stockholders . . . . . . . . . . . . . . . . . . . . . .

$(17,904)

Net loss per common share attributable to common stockholders:

Basic and diluted — as reported. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic and diluted — pro forma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ (57.79)
$ (61.40)

60

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

B. Accounting Policies — (Continued)

The following weighted-average input assumptions were used in determining the fair value:

Volatility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Risk-free interest rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected life of option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expected dividend yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Net Loss per Share

2007

73.4%
5.3%
5.36 years
0.0%

December 31,
2006

53.6%
4.8%
4.0 years
0.0%

2005

49.8%
3.7%
4.0 years
0.0%

Basic and diluted net loss per share attributable to common stockholders is presented in conformity with

SFAS No. 128, Earnings Per Share, for all periods presented. In accordance with SFAS No. 128, basic and
diluted net loss per share has been computed using the weighted-average number of common stock outstanding
during the period.

The change to the conversion ratios of the convertible preferred stock in June 2007 represented an
induced conversion, which resulted in a deemed dividend in the amount of $4.8 million that was included in
determining the net loss attributable to common stockholders in 2007.

The Company has outstanding options and warrants, and prior to June 8, 2007, had outstanding options,

warrants, convertible debt and convertible preferred stock, which have not been used in the calculation of
diluted net loss per share because, to do so would be anti-dilutive. As such, the numerator and the denominator
used in computing both basic and diluted net loss per share are equal. The following instruments were
excluded from the calculation of diluted net loss per share attributable to common stockholders because their
effects were antidilutive:

(cid:129) Outstanding stock options to purchase 3,679,884, 116,083, and 138,795 shares of common stock for the

years ended December 31, 2007, 2006 and 2005, respectively;

(cid:129) Warrants to purchase 5,125,496, 25,639, and 25,639 shares of common stock for the years ended

December 31, 2007, 2006 and 2005, respectively;

(cid:129) Shares of common stock issuable upon conversion of convertible preferred stock in the amount of

160,041 for the year ended December 31, 2007 and 364,524 for both the years ended December 31,
2006 and 2005; and

(cid:129) Shares of common stock issuable upon the conversion of the convertible promissory notes in the

amount of 112,098 and 72,995 for the years ended December 31, 2007 and 2006.

Reclassification

Certain prior year deposits have been reclassified from current assets to long-term assets to conform with

the current year presentation.

Recently Issued Accounting Standard

In September 2006, the FASB issued SFAS No. 157, Fair Value Measurements, (“SFAS No. 157”), which
creates a framework for measuring fair value, clarifies the definition of fair value and expands the disclosures
regarding fair value measurements. SFAS No. 157 does not require any new fair value measurements and is
effective for fiscal years beginning after November 15, 2007, thus January 1, 2008. The Company adopted the
new standard as of the effective date and currently does not believe the adoption will have a material impact

61

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

B. Accounting Policies — (Continued)

on its financial position or future results as it is already performing its investment valuation calculations and
estimating the fair value of its financial instruments using methodology that is principally consistent with
SFAS No. 157. The Company will continue to study the impact that SFAS No. 157 will have on future
disclosures of the fair values of our nonfinancial assets and liabilities.

C. Equipment

Equipment consists of (in thousands):

Laboratory equipment
Office equipment and leasehold improvements . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 5,839
3,481

$ 5,825
3,334

December 31,

2007

2006

Accumulated depreciation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9,320
(8,933)

9,159
(8,650)

$

387

$

509

D. Notes Receivable; MCL Acquisition

Note Receivable from Officer

The Company had a note receivable from an officer with an unpaid principal and interest balance of

$122,000 in connection with a loan made in 2002, which was forgiven in 2006.

MCL Acquisition and Note Receivable

In 2003, the Company acquired MCL LLC (“MCL”) through a merger with one of its subsidiaries. The

Company acquired its adult stem cell technology through the merger. In addition to the purchase price for the
merger, the Company was obligated to make three milestone payments. The first milestone, related to the
issuance of a patent, was completed in 2006 resulting in the issuance of 2,758 shares of common stock to the
former members of MCL. The value placed on the shares was approximately $125,000 using a fair value
estimate at the time of the milestone achievement. In 2007, the Company achieved the final two milestones,
which related to collaborative activities and the filing of an investigational new drug application with the
U.S. Food and Drug Administration. The milestones resulted in the issuance of 1,379 shares of the Company’s
common stock and cash payments of $1,000,000 in 2007. The value of the shares was approximately $7,000
using a fair value estimate at the time of the milestone achievement.

In connection with the MCL merger, the Company received a $511,000 note issued by one of the former

owners of MCL. Under the terms of the note, interest accrued on the unpaid principal at approximately 5%
per annum for the first two years, and the further accrual of interest would cease until one year after the
Company’s common stock became publicly-traded. In November 2005, interest on the note ceased to accrue,
but will resume accruing in June 2008 as a result of the Company’s Merger.

Principal and accrued interest is repayable (i) out of a percentage of proceeds from the sale of shares of
common stock held by the former owner (who owned 28,662 shares at December 31, 2007), and (ii) upon the
achievement of the final cash milestone, $283,000 of the final cash milestone can be withheld by Athersys as
partial repayment of the note. The Company achieved the final milestone in 2007 and therefore, withheld
$283,000 of the milestone payment as partial repayment on the note. The Company recorded an allowance of
$192,568 in 2007 to reserve a portion of the note balance for which collectability is uncertain, leaving a net
balance of $86,000 at December 31, 2007. In the event that the proceeds from the sale of common stock by

62

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

D. Notes Receivable; MCL Acquisition — (Continued)

the former owner are insufficient to repay the principal and interest in full, any remaining balance due will be
forgiven by Athersys at that time.

E. Financial Instruments

Investments

The following is a summary of available for sale securities (in thousands) at December 31, 2007:

Floating Rate Notes . . . . . . . . . . . . . . . . . . . . . . . .
Debt securities issued by U.S. Treasury . . . . . . . . . .
Corporate debt securities . . . . . . . . . . . . . . . . . . . . .
Commercial paper. . . . . . . . . . . . . . . . . . . . . . . . . .

Amortized
Cost

$ 6,000
20,400
3,336
6,539

$36,275

Gross
Unrealized
Losses

Gross
Unrealized
Gains

Estimated
Fair
Value

$—
—
(6)
—

$ (6)

$—
49
9
—

$58

$ 6,000
20,449
3,339
6,539

$36,327

Estimated fair values are based on quoted market prices. The Company had no realized gains or losses on

the sale of available for sale securities for any of the periods presented. Unrealized gains and losses on the
Company’s available-for-sale securities are excluded from earnings and are reported as a separate component
of stockholders’ equity within accumulated other comprehensive income until realized. When available-for-sale
securities are sold in the future, the cost of the securities will be specifically identified and used to determine
any realized gain or loss. The net unrealized gain on available for sale securities was $52,000 as of
December 31, 2007.

The amortized cost of and estimated fair value of available-for-sale securities at December 31, 2007, by

contractual maturity, are shown below. Actual maturities may differ from contractual maturities because the
issuers of the securities may have the right to repay the obligations without prepayment penalties. Although
the investments are available-for-sale, it is the Company’s intention to hold the investments classified as long-
term for more than a year from December 31, 2007 (in thousands).

December 31, 2007

Amortized
Cost

Estimated
Fair Value

Due in one year or less . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Due after one year through two years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$22,439
13,836

$22,477
13,850

$36,275

$36,327

Financing Arrangements

The Company leases office and laboratory space under an operating lease. The Company initially entered

into the lease in 2000 and has options to renew the lease in annual increments through March 2013 at the
initial rental rate. The Company executed options to renew through March 2010. Rent expense for the facility
was approximately $267,000 in each of 2007, 2006 and 2005.

In February 2008, the Company entered into a three-year lease agreement for office and laboratory space

for its Belgian subsidiary, with annual rent expense of approximately $45,000, subject to annual adjustments
based on an inflationary index. The lease includes an option to expand, which, if exercised, would result in
annual rent of approximately $85,000. The lease includes an option to renew for four additional years, through
December 31, 2014.

63

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

E. Financial Instruments — (Continued)

The future annual minimum lease commitments at December 31, 2007 are approximately $309,000 for

2008, $315,000 for 2009, and $117,000 for 2010.

Long-Term Debt

A summary of the Company’s long-term debt outstanding is as follows (in thousands):

Notes payable to lenders; issued November 2004; matures June 2008, including

$487,500 terminal payment; 13% interest rate; secured . . . . . . . . . . . . . . . . . .
Discount related to warrant issuance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$1,800
(16)

$5,132
—

Total, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Less — current portion, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1,784
1,784

5,132
3,332

Long-term debt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ — $1,800

December 31,

2007

2006

In November 2004, the Company issued a $7,500,000 note payable to lenders, the proceeds of which

were unrestricted and used for general corporate purposes. The notes are payable in 30 monthly installments
after the initial interest-only period that expired on December 1, 2005, with a fixed interest rate of 13% and a
maturity date of June 1, 2008. A terminal payment of $487,500 is due June 1, 2008. The debt has no financial
covenants and is secured by substantially all of the Company’s assets, excluding intellectual property, unless
the Company’s cash balance falls below a defined threshold. Deferred financing costs of $44,000 were
capitalized in 2004 in connection with the note, which were being amortized over the term of the note using
the effective interest method and will be fully amortized in 2008.

The lenders have the right to receive a milestone payment of $2.25 million upon the occurrence of certain

events as clarified in the October 2007 amendment to the loan agreement as follows: (1) the entire amount
upon (a) the merger with or into another entity where the Company’s stockholders do not hold at least a
majority of the voting power of the surviving entity, (b) the sale of all or substantially all of the Company’s
assets, and (c) the Company’s liquidation or dissolution; or (2) a portion of the amount from proceeds of
equity financings not tied to specific research and development activities that are part of a research or
development collaboration. In this case, the lenders will receive an amount equal to 10% of proceeds above
$5.0 million in cumulative gross proceeds until the milestone amount is paid in full. The milestone payment is
payable in cash, except that if the milestone event is (2) above, the Company may elect to pay 75% of the
milestone in shares of common stock at the per-share offering price. No amounts have been recorded in
relation to the milestone as of December 31, 2007.

The lenders also received warrants to purchase 149,026 shares of common stock with an exercise price of

$5.00 upon the closing of the Offering in June 2007. The value of the warrants was $492,000 based on the
Black-Scholes valuation of the underlying security, of which $476,000 was recorded as interest expense in
2007 and the remaining $16,000 of which will be expensed in 2008.

In September 2006, the agreement governing the note was amended to provide for a potential deferral of
four monthly principal payments. Two such principal payments were deferred, and were subsequently repaid
along with accumulated interest in January 2007. The amortization of the remaining loan balance was based
on the original terms and was not adjusted as a result of the amendment. The scheduled maturity of long-term
debt is $1.8 million in 2008.

64

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

E. Financial Instruments — (Continued)

Fair value of the Company’s long-term debt at December 31, 2007 is not determinable due to lack of

marketability of the fixed-rate debt. The Company paid interest of $456,000, $832,000 and $964,000 during
the years ended December 31, 2007, 2006 and 2005, respectively.

F. Collaboration

In 2006, the Company entered into a co-development collaboration with Angiotech. The Company issued
a $5 million convertible promissory note to Angiotech at the inception of the program, which was followed by
the issuance of an additional convertible promissory note of $5 million in January 2007 upon the achievement
of certain milestones. The notes bore interest at 5% and had a six-year term. Upon the closing of the Offering,
the convertible notes aggregating $10.0 million were converted along with accrued interest into
1,885,890 shares of common stock at a conversion price of $5.50 per share, which was 110% of the price per
share in the Offering, in accordance with the terms of the notes.

The Company may receive equity investments and cash payments based on the successful achievement of

specified clinical development and commercialization milestones. Under the terms of the collaboration,
preclinical costs are borne solely by the Company and the parties jointly fund clinical development activity.
The Company has primary responsibility for preclinical and early clinical development and clinical manufac-
turing, and Angiotech will take the lead on pivotal and later clinical trials and commercialization as further
described below. The parties will share net profits from the future sale of approved products.

In December 2007, the Company achieved a clinical development milestone upon the authorization of an

investigation new drug application by the U.S. Food and Drug Administration. This milestone event required
Angiotech to either purchase $5.0 million of common stock of Athersys, or forego the purchase and allow
Athersys to select from two pre-defined milestone replacements. Angiotech opted to forego the purchase and
Athersys elected to increase its share of the net profits from the future sale of approved products as the
replacement milestone.

Under the terms of the collaboration, the parties jointly fund clinical development activity, whereby costs
for phase I and II studies are borne 50% by Athersys and 50% by Angiotech, costs for the first phase III study
will be borne 33% by Athersys and 67% by Angiotech, and costs for any phase III studies subsequent to the
first phase III study will be borne 25% by Athersys and 75% by Angiotech. Late in 2007, the parties began to
share costs for phase I clinical development. The Company considered the provisions of EITF Issue No. 07-1,
Accounting for Collaborative Arrangements, and determined that neither party is a principal party for clinical
development costs, since both the costs and responsibilities are shared and neither party is in the business of
conducting clinical development services for others. Therefore, the Company recorded clinical development
costs net of Angiotech’s 50% cost-share, which amounted to $63,000 in 2007. The $63,000 was due from
Angiotech at December 31, 2007 and is disclosed separately on the balance sheet.

G. Convertible Bridge Notes

In 2006, the Company completed a bridge financing of $2.5 million in the form of convertible promissory

notes. The notes were issued primarily to existing stockholders of the Company, including $205,000 to three
members of management. The notes bore interest at 10% and had a three-year term. The notes were only
convertible into shares of stock of the same class as issued in the Company’s next bona fide equity financing,
at a conversion price equal to the price per share in the bona fide equity financing. The notes, if not converted,
were repayable with accrued interest at maturity, plus a repayment fee of 200% of the outstanding principal.

The bridge investors also received warrants in connection with the bridge financing. The warrants were
exercisable for shares of common stock only upon a restructuring of the Company’s capital stock in connection
with a bona fide financing. The number of shares that could be purchased under the warrants was based on a

65

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

G. Convertible Bridge Notes — (Continued)

formula whereby the bridge investors would receive warrants valued at two times their investment divided by
the pre-money value of the Company upon a restructuring and bona fide equity financing. The exercise price
of the warrants was $0.01 per share.

The Company allocated $250,000 of the purchase price of the debt to the warrants based on the relative

fair value of the notes and the warrants. The Company computed a premium on the debt in the amount of
$5,250,000 due upon redemption, which was being accreted over the term of the notes using the effective
interest method.

Upon the closing of the Offering, the bridge notes were converted along with accrued interest into

531,781 shares of common stock at a conversion price of $5.00 per share. The unamortized premium and
discount on the notes were eliminated and recorded as additional paid-in capital. The bridge noteholders also
exercised their warrants upon the closing of the Offering for 999,977 shares of common stock at an aggregate
exercise price of $10,000. Upon the conversion of the bridge notes, the bridge noteholders also received
five-year warrants to purchase 132,945 shares of common stock at $6.00 per share, which terms were
consistent with the warrants issued to new investors in the Offering.

H. Capitalization

At December 31, 2007, the Company has 100.0 million shares of common stock and 10.0 million shares
of undesignated preferred stock authorized. No shares of preferred stock have been issued as of December 31,
2007.

The Company may issue shares of common stock to its lenders and to Angiotech in connection with
future milestones (see Notes E and F). Also, the Company entered into a license and sponsored research
agreement in 2007 with an academic institution whereby, in addition to annual research funding, the institution
may receive 1,345 shares of common stock on each of five anniversary dates. The issuance of the shares is
subject to Board approval and the continuation of sponsored research at the institution. If the Board does not
approve the issuance of the shares, then the Company will remit $20,000 in cash plus the value of the shares,
as defined, to the institution on the anniversary dates.

As described in Note A, all of Old Athersys’ pre-Merger convertible preferred stock, outstanding
warrants, accrued dividends and treasury shares were terminated in connection with the Merger. The holders
of the majority of Old Athersys’ pre-Merger shares of preferred stock retained certain registration rights. Prior
to the Merger, Old Athersys had the following preferred stock outstanding:

(cid:129) Convertible Class A, B, C, D, F and G Preferred stock, which generally were entitled to voting rights,

dividends when declared, liquidation rights, and conversion rights at the holders election on a 1:1 basis;

(cid:129) Convertible Class C and E Preferred Stock carried cumulative, accrued dividends; and

(cid:129) The Class E Preferred Stock had limited voting rights and liquidation rights. As of October 2005, the
shares of Class E Preferred stock were no longer convertible into shares of common stock, and the
accrued dividend was no longer payable.

66

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

H. Capitalization — (Continued)

The following shares of common stock were reserved for future issuance (in thousands):

December 31

2007

2006

Stock option plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,500
277
—
365
Conversion of Class A, B, C, D, F, and G preferred stock . . . . . . . . . . . . . . . . . . . .
—
Conversion of unissued blank check preferred stock . . . . . . . . . . . . . . . . . . . . . . . .
9
— 1,887
Conversion of convertible notes — Angiotech* . . . . . . . . . . . . . . . . . . . . . . . . . . . .
—
532
Conversion of convertible notes — Bridge investors* . . . . . . . . . . . . . . . . . . . . . . . .
— 1,000
Warrants to purchase common stock — Bridge investors* . . . . . . . . . . . . . . . . . . . .
Warrants to purchase common stock — Offering . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,976
—
149
149
Warrants to purchase common stock — Lenders* . . . . . . . . . . . . . . . . . . . . . . . . . .
—
26
Warrant to purchase common stock — Miscellaneous . . . . . . . . . . . . . . . . . . . . . . .

9,625

4,245

* Amounts were not determinable at December 31, 2006, but were determined in June 2007 in connection

with the Offering

I. Joint Venture

Athersys owns 50.2% of Oculus Pharmaceuticals, Inc. (“Oculus”) related to a 2001 joint venture.
Athersys accounts for its investment in Oculus under the equity method due to significant minority investor
rights (i.e., “substantive participating rights,” as defined by EITF 96-16) retained by the other investors. In
2006, a milestone was achieved and Athersys received $100,000 of stock-based proceeds in another company
related to its investment in Oculus, which is included in ’other income’ on the Company’s 2006 statement of
operations.

Also in connection with the milestone achievement in 2006, Oculus received stock-based proceeds in
another company in the amount of $260,000. Athersys recognized approximately $117,000 as its share of the
Oculus net income, after recapturing prior losses in excess of the Company’s investment in and advances to
the joint venture. Consistent with its wind-up strategy, Oculus will remain in existence as a dormant entity
only as long as it is necessary to serve as a pass through of any further milestone-based consideration and
final distribution to its remaining shareholders. As of December 31, 2007 and 2006, Oculus had no significant
assets, liabilities, stockholders’ equity or results of operations, other than the milestone proceeds in 2006 as
described above.

J. Stock Option Plans

In 2007, the Company adopted two incentive plans that authorized an aggregate of 4,500,000 shares of

common stock for awards to employees, directors and consultants. These equity incentive plans authorize the
issuance of equity-based compensation in the form of stock options, stock appreciation rights, restricted stock,
restricted stock units, performance shares and units, and other stock-based awards to qualified employees,
directors and consultants.

In May 2007, the majority of Old Athersys’ pre-Merger outstanding options were terminated. The
Company accounted for the termination of these awards as a settlement and all previously unrecognized
compensation expense ($385,000) was recognized on the termination date in 2007. New option awards to
purchase 3,625,000 shares of common stock with an exercise price of $5.00 per share were granted to

67

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

J. Stock Option Plans — (Continued)

employees, directors and consultants in June 2007 upon the closing of the Merger. The options that were
granted to employees generally vested 40% on the date of grant and vest ratably over three years. The options
granted to non-employees and board members generally vest at varying percentages over three years.

Prior to the Merger in 2007, Old Athersys maintained equity incentive plans in which 277,000 shares
were available for issuance and 116,083 options were outstanding at December 31, 2006. Upon the closing of
the Merger, BTHC VI assumed 5,052 of these options, which will be governed by Old Athersys’ original
equity plans until the awards expire. As of December 31, 2007, 4,634 of these assumed awards remain
outstanding. All of the remaining outstanding option awards under Old Athersys’ former equity incentive plans
were terminated prior to the Merger.

As of December 31, 2007, a total of 824,750 shares are available for issuance under the Company’s
equity compensation plans and options covering 3,679,884 shares of common stock are outstanding (including
the 4,634 assumed options described above). The Company recognized $5,139,000, $457,000 and $1,459,000
of stock compensation expense in 2007, 2006 and 2005, respectively. At December 31, 2007, total
unrecognized compensation expense related to unvested stock options was approximately $5,017,000, which is
expected to be recognized ratably by December 31, 2011 using the straight-line method. The weighted average
fair value of option shares granted in 2007, 2006 and 2005 was $2.82, $0 and $154.81 per share, respectively.
The total fair value of option shares vested in 2007, 2006 and 2005 was $4,742,000, $428,000, and
$2,312,000, respectively. There is no aggregate intrinsic value of fully vested option shares and option shares
expected to vest as of December 31, 2007 since the market value was less than the exercise price of the
options at the end of the year.

A summary of the Company’s stock option activity and related information is as follows:

Outstanding January 1, 2005. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Outstanding December 31, 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forfeited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Number of
Options

149,017
1,470
(63)
(11,628)

138,796
—
(72)
(22,641)

Outstanding December 31, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

116,083
Granted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,738,000
—
Exercised . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(174,199)
Forfeited/Terminated/Expired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Outstanding December 31, 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,679,884

Vested during 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,663,957
Vested and exercisable at December 31, 2007 . . . . . . . . . . . . . . . . . . . . . . . . 1,668,591

Weighted
Average
Exercise
Price

$ 92.61
362.63
41.84
133.89

92.05
—
83.68
150.91

80.62
5.06
—
51.21

5.24

5.02
5.42

$

$
$

68

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

J. Stock Option Plans — (Continued)

December 31, 2007

Exercise Price

$ 4.99-
7.80
$69.74-278.95

Options Outstanding
Weighted
Average
Remaining
Contractual
Life

Number of
Options

3,675,250
4,634

3,679,884

8.45
2.25

Weighted
Average
Exercise
Price

$
5.06
$152.08

Options Vested and Exercisable
Weighted
Average
Remaining
Contractual
Life

Weighted
Average
Exercise
Price

Number of
Options

1,663,957
4,634

1,668,591

8.76
2.25

$
5.02
$152.08

The weighted average contractual life of unvested options at December 31, 2007 was 8.2 years.

K.

Income Taxes

At December 31, 2007, the Company had net operating loss and research and development tax credit
carryforwards of approximately $7,021,000 and $438,000, respectively, for income tax purposes. Such losses
and credits may be used to reduce future taxable income and tax liabilities and will expire in 2027.

As a result of the change in ownership related to the capital restructuring and Offering, the Company lost

the use of a significant portion of Athersys’ pre-Merger net operating loss carryforwards. The remaining pre-
merger net operating loss carryforward of approximately $9,018,000 (“Pre-Merger NOL”) is limited for use
under Section 382 of the Internal Revenue Code to an annual net operating loss carryforward of $464,000.
The Pre-Merger NOL may be used to reduce future taxable income and tax liabilities and will expire at
various dates between 2010 and 2027.

Significant components of the Company’s deferred tax assets are as follows (in thousands):

December 31,

2007

2006

Net operating loss carryforwards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net operating loss carryforwards — Pre-Merger NOL . . . . . . . . . . . . . . . . . . .
Research and development credit carryforwards. . . . . . . . . . . . . . . . . . . . . . . .
Compensation expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ 2,387
3,066
438
1,221
539

$

—
37,369
5,759
4,275
568

Total deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valuation allowance for deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . .

7,651
(7,651)

47,971
(47,971)

Net deferred tax assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$ — $

—

Because of the Company’s cumulative losses, the deferred tax assets have been fully offset by a valuation

allowance. The Company has not paid income taxes for the three-year period ended December 31, 2007.

In July 2006, the FASB issued FASB Interpretation No. 48 (“FIN 48”), Accounting for Uncertainty in
Income Taxes, which is applicable for fiscal years beginning after December 15, 2006. FIN 48 prescribes a
recognition threshold and measurement attribute for financial statement recognition and measurement of a tax
position reported or expected to be reported on a tax return as well as guidance on derecognition,
classification, interest and penalties, accounting in interim periods, disclosure, and transition. Athersys adopted
the provisions of FIN 48 on January 1, 2007. Upon adoption of FIN 48 and through December 31, 2007,
Athersys determined that it had no liability for uncertain income taxes as prescribed by FIN 48. Athersys’
policy is to recognize potential accrued interest and penalties related to the liability for uncertain tax benefits,

69

Athersys, Inc.

Notes to Consolidated Financial Statements — (Continued)

K.

Income Taxes — (Continued)

if applicable, in income tax expense. Net operating loss and credit carryforwards since inception remain open
to examination by taxing authorities, and will for a period post utilization.

L. Profit Sharing Plan and 401(k) Plan

The Company has a profit sharing and 401(k) plan that covers substantially all employees. The Plan

allows for discretionary contributions by the Company. The Company made no contributions to this plan in
2005, 2006 or 2007.

M. Quarterly Financial Data (unaudited)

The following table presents quarterly data for the years ended December 31, 2007 and 2006, in

thousands, except per share data:

First
Quarter

Second
Quarter

2007
Third
Quarter

Fourth
Quarter

Full
Year

Revenues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $
$ 3,260
Net loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $(2,720) $ (7,069) $(4,439) $(4,698) $(18,926)
Preferred stock dividends . . . . . . . . . . . . . . . . . . $ (375) $
(659)
Deemed dividend resulting from induced

(284) $ — $ — $

723

879

798

860

$

$

$

conversion of convertible preferred stock . . . . $ — $ (4,800) $ — $ — $ (4,800)
Net loss attributable to common stockholders . . . $(3,095) $(12,153) $(4,439) $(4,698) $(24,385)
Basic and diluted net loss per common share

attributable to common stockholders . . . . . . $(10.54) $

(2.53) $ (0.23) $ (0.25) $

(2.26)

First
Quarter

Second
Quarter

2006
Third
Quarter

Fourth
Quarter

Full
Year

Revenues. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $
Loss before cumulative effect of change in

629

$

490

$ 1,126 $ 1,480 $ 3,725

accounting principle . . . . . . . . . . . . . . . . . . . . . $(2,793) $(3,295) $(2,067) $(2,716) $(10,871)
Net loss. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $(2,487) $(3,295) $(2,067) $(2,716) $(10,565)
Preferred stock dividends . . . . . . . . . . . . . . . . . . . $ (348) $ (347) $ (347) $ (366) $ (1,408)
Net loss attributable to common stockholders . . . . $(2,835) $(3,642) $(2,414) $(3,082) $(11,973)
Basic and diluted net loss per common share

attributable to common stockholders:
Loss before cumulative effect of change in

accounting principle . . . . . . . . . . . . . . . . . . . . . $(10.78) $(12.40) $ (8.22) $(10.49) $ (41.89)

Cumulative effect of change in accounting

principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.05

—

—

—

1.05

Net loss. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ (9.73) $(12.40) $ (8.22) $(10.49) $ (40.84)

70

ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND

FINANCIAL DISCLOSURE

Not applicable.

ITEM 9A. CONTROLS AND PROCEDURES

Evaluation of disclosure controls and procedures: An evaluation was carried out under the supervision

and with the participation of our management, including our principal executive officer and our principal
financial officer, of the effectiveness of our disclosure controls and procedures as of the end of the period
covered by this annual report. Based on that evaluation, these officers have concluded that as of December 31,
2007, our disclosure controls and procedures are effective.

Management’s report on internal control over financial reporting: Management is responsible for
establishing and maintaining adequate internal control over financial reporting, as such term is defined in
Exchange Act Rule 13a-15(f). Under the supervision and with the participation of management, including our
principal executive officer and principal financial officer, we conducted an evaluation of the effectiveness of
internal control over financial reporting based on the framework in Internal Control — Integrated Framework
issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on this evaluation
under the framework in Internal Control — Integrated Framework, management concluded that our internal
control over financial reporting was effective as of December 31, 2007. Our internal control over financial
reporting as of December 31, 2007 has been audited by Ernst & Young LLP, an independent registered public
accounting firm, as stated in its report, which is included in Item 8 of this annual report on Form 10-K and
incorporated herein by reference.

Changes in internal control: During the fourth quarter of 2007, there has been no change in our internal

control over financial reporting that has materially affected, or is reasonably likely to materially affect, our
internal control over financial reporting.

ITEM 9B. OTHER INFORMATION

On March 13, 2008, our board of directors, based on the recommendation of the compensation committee,
approved a cash bonus incentive plan for the year ended December 31, 2008 for our executive officers. Under
the incentive plan, executive officers will be entitled to earn a bonus based upon the achievement of specified
company goals, as well as specified individual goals. There is no formally adopted plan document for the
incentive plan.

PART III

ITEM 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

The information regarding Athersys’ directors, including the identification of the audit committee and the
audit committee financial expert, is incorporated by reference to the information contained in Athersys’ Proxy
Statement with respect to the 2008 Annual Meeting of Stockholders, or the 2008 Proxy Statement. Information
concerning executive officers is contained in Item 4A of Part I of this annual report on Form 10-K under the
heading “Executive Officers of the Registrant.”

The information regarding Section 16(a) beneficial ownership reporting compliance is incorporated by
reference to the material under the heading “Section 16(a) Beneficial Ownership Reporting Compliance” in
the 2008 Proxy Statement.

The information regarding any changes in procedures by which stockholders may recommend nominees
to Athersys’ Board of Directors is incorporated by reference to the information contained in the 2008 Proxy
Statement.

Athersys has adopted a code of ethics that applies to its principal executive officer, principal financial

officer and principal accounting officer. Athersys’ code of ethics is posted under the Investors tab of its

71

website at www.athersys.com. Athersys will post any amendments to, or waivers of, its code of ethics that
apply to its principal executive officer, principal financial officer and principal accounting officer on its
website.

ITEM 11. EXECUTIVE COMPENSATION

The information regarding executive officer and director compensation is incorporated by reference to the

information contained in the 2008 Proxy Statement.

The information regarding compensation committee interlocks and insider participation and the compen-

sation committee report is incorporated by reference to the information contained in the 2008 Proxy
Statement.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

AND RELATED SHAREHOLDER MATTERS

The information regarding security ownership of certain beneficial owners and management is incorpo-

rated by reference to the information contained in the 2008 Proxy Statement.

Equity Compensation Plan Information. The following table sets forth certain information regarding the

Company’s equity compensation plans as of December 31, 2007, unless otherwise indicated.

Number of
Securities to
be Issued Upon
Exercise of
Outstanding
Options
(a)

Weighted-Average
Exercise Price of
Outstanding Options
(b)

Number of Securities
Remaining Available
for Future Issuance
Under Equity
Compensation
Plans (Excluding
Securities Reflected
in Column(a))
(c)

Plan Category

Equity compensation plan approved by

security holders. . . . . . . . . . . . . . . . . . .
Equity compensation plan not approved by
security holders(1) . . . . . . . . . . . . . . . .

2,442,750

1,237,134

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

3,679,884

$5.00

$5.72

592,250

232,500

824,750

(1) Includes 4,634 of shares of common stock issuable upon exercise of stock options that were assumed by

BTHC VI in the Merger.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR

INDEPENDENCE

The information regarding certain relationships and related transactions and director independence is

incorporated by reference to the information contained in the 2008 Proxy Statement.

ITEM 14. PRINCIPAL ACCOUNTANT FEES AND SERVICES

Information regarding fees paid to and services provided by our independent registered public accounting
firm during the fiscal years ended December 31, 2007 and 2006 and the pre-approval policies and procedures
of the audit committee is incorporated by reference to the information contained in the 2008 Proxy Statement.

72

PART IV

ITEM 15. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

(a)(1) Financial Statements:

The following consolidated financial statements of Athersys, Inc. are included in Item 8:

Reports of Independent Registered Public Accounting Firm

Consolidated Balance Sheets as of December 31, 2007 and 2006

Consolidated Statements of Operations for each of the years ended December 31, 2007, 2006 and
2005

Consolidated Statements of Stockholders’ Equity (Deficit) for each of the years ended December 31,
2007, 2006 and 2005

Consolidated Statements of Cash Flow for each of the years ended December 31, 2007, 2006 and
2005

Notes to Consolidated Financial Statements

(a)(2) Financial Statement Schedules:

The following financial statement schedule of Athersys, Inc. is included:

Schedule II — Valuation and Qualifying Accounts

Balance at
Beginning of
Year

Additions
(In thousands)

Deductions

Balance at
End of Year

Year Ended December 31, 2007
Deducted from asset accounts:

Allowance for doubtful accounts . . . . . . . . . . . . . . .
Tax valuation allowances . . . . . . . . . . . . . . . . . . . . .

$ —
47,971

$ 193(A)
1,954

$ —
42,274(B)

$

193
7,651

Total 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$47,971

$2,147

$42,274

$ 7,844

Year Ended December 31, 2006
Deducted from asset accounts:

Tax valuation allowances . . . . . . . . . . . . . . . . . . . . .

$43,974

Total 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$43,974

$3,997

$3,997

$ —(B) $47,971

$ —

$47,971

Year Ended December 31, 2005
Deducted from asset accounts:

Tax valuation allowances . . . . . . . . . . . . . . . . . . . . .

$38,861

Total 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$38,861

$5,113

$5,113

$ —(B) $43,974

$ —

$43,974

(A) — Reserve on note receivable.

(B) — Deferred tax assets are fully offset by valuation allowances. As a result of the June 2007 equity offer-
ing and merger, the Company lost the use of a significant portion of its pre-merger net operating loss
carryforwards.

All other schedules for which provision is made in the applicable accounting regulation of the SEC are

not required under the related instructions or are inapplicable and, therefore, omitted.

73

(a)(3) Exhibits.

Exhibit No.

Exhibit Description

2.1

2.2

3.1

3.2

10.1*

10.2*

10.3*

10.4

10.5

10.6

10.7

10.8

Agreement and Plan of Merger, dated as of May 24, 2007, by and among Athersys, Inc., BTHC
VI, Inc. and B-VI Acquisition Corp. (incorporated herein by reference to Exhibit 10.1 to
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on May 24, 2007)
First Amendment to Agreement and Plan of Merger, dated as of June 8, 2007, by and among
Athersys, Inc., BTHC VI, Inc. and B-VI Acquisition Corp. (incorporated herein by reference to
Exhibit 2.2 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Certificate of Incorporation of Athersys, Inc., as amended as of August 31, 2007 (incorporated
herein by reference to Exhibit 3.1 to the registrant’s Registration Statement on Form S-3/A
(Registration No. 333-144433) filed with the Commission on October 10, 2007)
Bylaws of Athersys, Inc., as amended as of October 30, 2007 (incorporated herein by reference to
Exhibit 3.1 to the registrant’s Current Report on Form 10-K (Commission No. 000-52108) filed
with the Commission on October 31, 2007)
Research Collaboration and License Agreement, dated as of December 8, 2000, by and between
Athersys, Inc. and Bristol-Myers Squibb Company (incorporated herein by reference to
Exhibit 10.1 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Cell Line Collaboration and License Agreement, dated as of July 1, 2002, by and between
Athersys, Inc. and Bristol-Myers Squibb Company (incorporated herein by reference to
Exhibit 10.2 to the registrant’s Current Report on Form 8-K/A (Commission No. 000-52108) filed
with the Commission on September 27, 2007)
Extended Collaboration and License Agreement, dated as of January 1, 2006, by and between
Athersys, Inc. and Bristol-Myers Squibb Company (incorporated herein by reference to
Exhibit 10.3 to the registrant’s Current Report on Form 8-K/A (Commission No. 000-52108) filed
with the Commission on September 27, 2007)
License Agreement, effective as of May 5, 2006, by and between Athersys, Inc. and Angiotech
Pharmaceuticals, Inc. (incorporated herein by reference to Exhibit 10.4 to the registrant’s Current
Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14, 2007)
Sublicense Agreement, effective as of May 5, 2006, by and between Athersys, Inc. and Angiotech
Pharmaceuticals, Inc. (incorporated herein by reference to Exhibit 10.5 to the registrant’s Current
Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14, 2007)
Amended and Restated Registration Rights Agreement, dated as of April 28, 2000, by and among
Athersys, Inc. and the stockholders of Athersys, Inc. parties thereto (incorporated herein by
reference to Exhibit 10.6 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Amendment No. 1 to Athersys, Inc. Amended and Restated Registration Rights Agreement, dated
as of January 29, 2002, by and among Athersys, Inc., the New Stockholders, the Investors,
Biotech and the Stockholders (each as defined in the Amended and Restated Registration Rights
Agreement, dated as April 28, 2000, by and among Athersys, Inc. and the stockholders of
Athersys, Inc. parties thereto) (incorporated herein by reference to Exhibit 10.7 to the registrant’s
Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14,
2007)
Amendment No. 2 to Athersys, Inc. Amended and Restated Registration Rights Agreement, dated
as of November 19, 2002, by and among Athersys, Inc., the New Stockholders, the Investors,
Biotech and the Stockholders (each as defined in the Amended and Restated Registration Rights
Agreement, dated as April 28, 2000, as amended, by and among Athersys, Inc. and the
stockholders of Athersys, Inc. parties thereto) (incorporated herein by reference to Exhibit 10.8 to
the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the
Commission on June 14, 2007)

74

Exhibit No.

10.9

10.10†

10.11†

10.12

10.13

10.14

10.15†

10.16†

10.17†

10.18†

10.19†

10.20†

Exhibit Description

Amendment No. 3 to Amended and Restated Registration Rights Agreement, dated as of May 15,
2007, by and among Athersys, Inc. and the Existing Stockholders (as defined therein)
(incorporated herein by reference to Exhibit 10.9 to the registrant’s Current Report on Form 8-K
(Commission No. 000-52108) filed with the Commission on June 14, 2007)
BTHC VI, Inc. Long-Term Incentive Plan (incorporated herein by reference to Exhibit 10.10 to
the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the
Commission on June 14, 2007)
BTHC VI, Inc. Equity Incentive Compensation Plan (incorporated herein by reference to
Exhibit 10.11 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Loan and Security Agreement, and Supplement, dated as of November 2, 2004, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc., Venture Lending & Leasing IV, Inc., and Costella
Kirsch IV, L.P. (incorporated herein by reference to Exhibit 10.1 to the registrant’s Quarterly
Report on Form 10-Q (Commission No. 000-52108) filed with the Commission on November 14,
2007)
Second Amendment to Loan and Security Agreement, dated as of October 30, 2007, by and
among ABT Holding Company, Advanced Biotherapeutics, Inc., Venture Lending and Leasing IV,
Inc., and Costella Kirsch IV, L.P. (incorporated herein by reference to Exhibit 10.2 to the
registrant’s Quarterly Report on Form 10-Q (Commission No. 000-52108) filed with the
Commission on November 14, 2007)
Amendment to Loan and Security Agreement, dated as of September 29, 2006, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc., Venture Lending & Leasing IV, Inc., and Costella
Kirsch IV, L.P. (incorporated herein by reference to Exhibit 10.13 to the registrant’s Current
Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14, 2007)
Amended and Restated Employment Agreement, dated as of December 1, 1998 but effective as of
April 1, 1998, by and between Athersys, Inc. and Dr. Gil Van Bokkelen (incorporated herein by
reference to Exhibit 10.14 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Amendment No. 1 to Amended and Restated Employment Agreement, dated as of May 31, 2007,
by and between Advanced Biotherapeutics, Inc. and Gil Van Bokkelen (incorporated herein by
reference to Exhibit 10.15 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of December 1, 1998, by and between
Athersys, Inc. and Dr. Gil Van Bokkelen (incorporated herein by reference to Exhibit 10.16 to the
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on June 14, 2007)
Amended and Restated Employment Agreement, dated as of December 1, 1998 but effective as of
April 1, 1998, by and between Athersys, Inc. and Dr. John J. Harrington (incorporated herein by
reference to Exhibit 10.17 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Amendment No. 1 to Amended and Restated Employment Agreement, dated as of May 31, 2007,
by and between Advanced Biotherapeutics, Inc. and John Harrington (incorporated herein by
reference to Exhibit 10.18 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of December 1, 1998, by and between
Athersys, Inc. and Dr. John J. Harrington (incorporated herein by reference to Exhibit 10.19 to the
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on June 14, 2007)

75

Exhibit No.

10.21†

10.22†

10.23†

10.24†

10.25†

10.26†

10.27†

10.28†

10.29†

10.30†

10.31†

10.32†

10.33†

Exhibit Description

Employment Agreement, dated as of May 22, 1998, by and between Athersys, Inc. and Laura K.
Campbell (incorporated herein by reference to Exhibit 10.20 to the registrant’s Current Report on
Form 8-K (Commission No. 000-52108) filed with the Commission on June 14, 2007)
Amendment No. 1 to Employment Agreement, dated as of May 31, 2007, by and between
Advanced Biotherapeutics, Inc. and Laura Campbell (incorporated herein by reference to
Exhibit 10.21 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Employment Agreement, dated as of September 25, 2000, by and between Advanced
Biotherapeutics, Inc. and Kurt Brunden (incorporated herein by reference to Exhibit 10.22 to the
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on June 14, 2007)
Amendment No. 1 to Employment Agreement, dated as of May 31, 2007, by and between
Advanced Biotherapeutics, Inc. and Kurt Brunden (incorporated herein by reference to
Exhibit 10.23 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of September 25, 2000, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc. and Kurt Brunden (incorporated herein by reference
to Exhibit 10.24 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108)
filed with the Commission on June 14, 2007)
Employment Agreement, dated as of October 3, 2003, by and between Advanced Biotherapeutics,
Inc. and Robert Deans, Ph.D. (incorporated herein by reference to Exhibit 10.25 to the registrant’s
Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14,
2007)
Amendment No. 1 to Employment Agreement, dated as of May 31, 2007, by and between
Advanced Biotherapeutics, Inc. and Robert Deans (incorporated herein by reference to
Exhibit 10.26 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of October 3, 2003, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc. and Robert Deans (incorporated herein by reference
to Exhibit 10.27 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108)
filed with the Commission on June 14, 2007)
Employment Agreement, dated as of January 1, 2004, by and between Advanced Biotherapeutics,
Inc. and William Lehmann (incorporated herein by reference to Exhibit 10.28 to the registrant’s
Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14,
2007)
Amendment No. 1 to Employment Agreement, dated as of May 31, 2007, by and between
Advanced Biotherapeutics, Inc. and William Lehmann (incorporated herein by reference to
Exhibit 10.29 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of September 10, 2001, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc. and William Lehmann (incorporated herein by
reference to Exhibit 10.30 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Form Incentive Agreement by and between Advanced Biotherapeutics, Inc. and named executive
officers, and acknowledged by Athersys, Inc. and ReGenesys, LLC (incorporated herein by
reference to Exhibit 10.31 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Form Amendment No. 1 to Incentive Agreement by and between Advanced Biotherapeutics, Inc.
and named executive officers, and acknowledged by Athersys, Inc. and ReGenesys, LLC
(incorporated herein by reference to Exhibit 10.32 to the registrant’s Current Report on Form 8-K
(Commission No. 000-52108) filed with the Commission on June 14, 2007)

76

Exhibit No.

10.34

10.35*

10.36*

10.37

10.38†

10.39†

10.40

21
23
24
31.1

31.2

32.1

Exhibit Description

Securities Purchase Agreement, dated as of June 8, 2007, by and among Athersys, BTHC VI, Inc.
and Investors (as defined therein) (incorporated herein by reference to Exhibit 10.33 to the
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on June 14, 2007)
Exclusive License Agreement, dated as of May 17, 2002, by and between Regents of the
University of Minnesota and MCL LLC, assumed by ReGenesys, LLC through operation of
merger on November 4, 2003 (incorporated herein by reference to Exhibit 10.34 to the registrant’s
Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14,
2007)
Strategic Alliance Agreement, by and between Athersys, Inc. and Angiotech Pharmaceuticals, Inc.,
dated as of May 5, 2006 (incorporated herein by reference to Exhibit 10.35 to the registrant’s
Current Report on Form 8-K/A (Commission No. 000-52108) filed with the Commission on
October 9, 2007)
Amendment No. 1 to Cell Line Collaboration and License Agreement, dated as of January 1,
2006, by and between Athersys, Inc. and Bristol-Myers Squibb Company (incorporated herein by
reference to Exhibit 10.36 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Consulting Agreement, by and among Athersys, Inc., Advanced Biotherapeutics, Inc. and Dr. Kurt
Brunden, dated as of July 23, 2007 (incorporated herein by reference to Exhibit 10.13 to the
registrant’s Quarterly Report on Form 10-Q (Commission No. 000-52108) filed with the
Commission on August 17, 2007)
Form Indemnification Agreement for Directors, Officers and Directors and Officers (incorporated
herein by reference to Exhibit 10.1 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on August 6, 2007)
Advisory Agreement, dated as of May 24, 2007, by and between Halter Financial Group, L.P. and
Athersys, Inc. (incorporated herein by reference to Exhibit 10.40 to the registrant’s Registration
Statement on Form S-1/A (Registration No. 333-144433) filed with the Commission on
September 12, 2007).
List of Subsidiaries
Consent of Ernst & Young LLP, Independent Registered Public Accounting Firm
Power of Attorney
Certification of Gil Van Bokkelen, Chairman and Chief Executive Officer, pursuant to SEC
Rules 13a-14(a) and 15d-14(a) adopted pursuant to Section 302 of the Sarbanes-Oxley Act of
2002.
Certification of Laura Campbell, Vice President of Finance, pursuant to SEC Rules 13a-14(a) and
15d-14(a) adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
Certification of Gil Van Bokkelen, Chairman and Chief Executive Officer, and Laura Campbell,
Vice President of Finance, pursuant to 18 U.S.C. Section 1350, adopted pursuant to Section 906 of
the Sarbanes-Oxley Act of 2002.

* Confidential treatment requested as to certain portions, which portions have been filed separately with the

Securities and Exchange Commission

† Indicates management contract or compensatory plan, contract or arrangement in which one or more direc-

tors or executive officers of the registrant may be participants

77

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, in the city
of Cleveland, State of Ohio, on March 14, 2008.

SIGNATURES

ATHERSYS, INC.

By: /s/ Gil Van Bokkelen
Gil Van Bokkelen
Title:

Chief Executive Officer

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 and in the capacities and on the date indicated.

Signature

Title

Date

/s/ Gil Van Bokkelen
Gil Van Bokkelen

/s/ Laura K. Campbell
Laura K. Campbell

*
John J. Harrington

*
William C. Mulligan

*
George M. Milne, Jr.

*
Jordan S. Davis

*
Floyd D. Loop

*
Michael Sheffery

*
Lorin J. Randall

Chief Executive Officer and Chairman of
the Board of Directors
(Principal Executive Officer)

March 14, 2008

Vice President, Finance
(Principal Financial Officer and Principal
Accounting Officer)

March 14, 2008

Executive Vice President, Chief Scientific
Officer and Director

March 14, 2008

Director

March 14, 2008

Director

Director

March 14, 2008

March 14, 2008

Director

March 14, 2008

Director

March 14, 2008

Director

March 14, 2008

* Gil Van Bokkelen, by signing his name hereto, does hereby sign this Form 10-K on behalf of each of the
above named and designated directors of the Company pursuant to a Power of Attorney executed by such
persons and filed with the Securities and Exchange Commission.

By: /s/ Gil Van Bokkelen
Gil Van Bokkelen
Attorney-in-fact

78

Exhibit No.

Exhibit Description

EXHIBIT INDEX

2.1

2.2

3.1

3.2

10.1*

10.2*

10.3*

10.4

10.5

10.6

10.7

10.8

Agreement and Plan of Merger, dated as of May 24, 2007, by and among Athersys, Inc., BTHC
VI, Inc. and B-VI Acquisition Corp. (incorporated herein by reference to Exhibit 10.1 to
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on May 24, 2007)
First Amendment to Agreement and Plan of Merger, dated as of June 8, 2007, by and among
Athersys, Inc., BTHC VI, Inc. and B-VI Acquisition Corp. (incorporated herein by reference to
Exhibit 2.2 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Certificate of Incorporation of Athersys, Inc., as amended as of August 31, 2007 (incorporated
herein by reference to Exhibit 3.1 to the registrant’s Registration Statement on Form S-3/A
(Registration No. 333-144433) filed with the Commission on October 10, 2007)
Bylaws of Athersys, Inc., as amended as of October 30, 2007 (incorporated herein by reference to
Exhibit 3.1 to the registrant’s Current Report on Form 10-K (Commission No. 000-52108) filed
with the Commission on October 31, 2007)
Research Collaboration and License Agreement, dated as of December 8, 2000, by and between
Athersys, Inc. and Bristol-Myers Squibb Company (incorporated herein by reference to
Exhibit 10.1 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Cell Line Collaboration and License Agreement, dated as of July 1, 2002, by and between
Athersys, Inc. and Bristol-Myers Squibb Company (incorporated herein by reference to
Exhibit 10.2 to the registrant’s Current Report on Form 8-K/A (Commission No. 000-52108) filed
with the Commission on September 27, 2007)
Extended Collaboration and License Agreement, dated as of January 1, 2006, by and between
Athersys, Inc. and Bristol-Myers Squibb Company (incorporated herein by reference to
Exhibit 10.3 to the registrant’s Current Report on Form 8-K/A (Commission No. 000-52108) filed
with the Commission on September 27, 2007)
License Agreement, effective as of May 5, 2006, by and between Athersys, Inc. and Angiotech
Pharmaceuticals, Inc. (incorporated herein by reference to Exhibit 10.4 to the registrant’s Current
Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14, 2007)
Sublicense Agreement, effective as of May 5, 2006, by and between Athersys, Inc. and Angiotech
Pharmaceuticals, Inc. (incorporated herein by reference to Exhibit 10.5 to the registrant’s Current
Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14, 2007)
Amended and Restated Registration Rights Agreement, dated as of April 28, 2000, by and among
Athersys, Inc. and the stockholders of Athersys, Inc. parties thereto (incorporated herein by
reference to Exhibit 10.6 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Amendment No. 1 to Athersys, Inc. Amended and Restated Registration Rights Agreement, dated
as of January 29, 2002, by and among Athersys, Inc., the New Stockholders, the Investors,
Biotech and the Stockholders (each as defined in the Amended and Restated Registration Rights
Agreement, dated as April 28, 2000, by and among Athersys, Inc. and the stockholders of
Athersys, Inc. parties thereto) (incorporated herein by reference to Exhibit 10.7 to the registrant’s
Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14,
2007)
Amendment No. 2 to Athersys, Inc. Amended and Restated Registration Rights Agreement, dated
as of November 19, 2002, by and among Athersys, Inc., the New Stockholders, the Investors,
Biotech and the Stockholders (each as defined in the Amended and Restated Registration Rights
Agreement, dated as April 28, 2000, as amended, by and among Athersys, Inc. and the
stockholders of Athersys, Inc. parties thereto) (incorporated herein by reference to Exhibit 10.8 to
the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the
Commission on June 14, 2007)

79

Exhibit No.

10.9

10.10†

10.11†

10.12

10.13

10.14

10.15†

10.16†

10.17†

10.18†

10.19†

10.20†

Exhibit Description

Amendment No. 3 to Amended and Restated Registration Rights Agreement, dated as of May 15,
2007, by and among Athersys, Inc. and the Existing Stockholders (as defined therein)
(incorporated herein by reference to Exhibit 10.9 to the registrant’s Current Report on Form 8-K
(Commission No. 000-52108) filed with the Commission on June 14, 2007)
BTHC VI, Inc. Long-Term Incentive Plan (incorporated herein by reference to Exhibit 10.10 to
the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the
Commission on June 14, 2007)
BTHC VI, Inc. Equity Incentive Compensation Plan (incorporated herein by reference to
Exhibit 10.11 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Loan and Security Agreement, and Supplement, dated as of November 2, 2004, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc., Venture Lending & Leasing IV, Inc., and Costella
Kirsch IV, L.P. (incorporated herein by reference to Exhibit 10.1 to the registrant’s Quarterly
Report on Form 10-Q (Commission No. 000-52108) filed with the Commission on November 14,
2007)
Second Amendment to Loan and Security Agreement, dated as of October 30, 2007, by and
among ABT Holding Company, Advanced Biotherapeutics, Inc., Venture Lending and Leasing IV,
Inc., and Costella Kirsch IV, L.P. (incorporated herein by reference to Exhibit 10.2 to the
registrant’s Quarterly Report on Form 10-Q (Commission No. 000-52108) filed with the
Commission on November 14, 2007)
Amendment to Loan and Security Agreement, dated as of September 29, 2006, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc., Venture Lending & Leasing IV, Inc., and Costella
Kirsch IV, L.P. (incorporated herein by reference to Exhibit 10.13 to the registrant’s Current
Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14, 2007)
Amended and Restated Employment Agreement, dated as of December 1, 1998 but effective as of
April 1, 1998, by and between Athersys, Inc. and Dr. Gil Van Bokkelen (incorporated herein by
reference to Exhibit 10.14 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Amendment No. 1 to Amended and Restated Employment Agreement, dated as of May 31, 2007,
by and between Advanced Biotherapeutics, Inc. and Gil Van Bokkelen (incorporated herein by
reference to Exhibit 10.15 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of December 1, 1998, by and between
Athersys, Inc. and Dr. Gil Van Bokkelen (incorporated herein by reference to Exhibit 10.16 to the
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on June 14, 2007)
Amended and Restated Employment Agreement, dated as of December 1, 1998 but effective as of
April 1, 1998, by and between Athersys, Inc. and Dr. John J. Harrington (incorporated herein by
reference to Exhibit 10.17 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Amendment No. 1 to Amended and Restated Employment Agreement, dated as of May 31, 2007,
by and between Advanced Biotherapeutics, Inc. and John Harrington (incorporated herein by
reference to Exhibit 10.18 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of December 1, 1998, by and between
Athersys, Inc. and Dr. John J. Harrington (incorporated herein by reference to Exhibit 10.19 to the
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on June 14, 2007)

80

Exhibit No.

10.21†

10.22†

10.23†

10.24†

10.25†

10.26†

10.27†

10.28†

10.29†

10.30†

10.31†

10.32†

10.33†

Exhibit Description

Employment Agreement, dated as of May 22, 1998, by and between Athersys, Inc. and Laura K.
Campbell (incorporated herein by reference to Exhibit 10.20 to the registrant’s Current Report on
Form 8-K (Commission No. 000-52108) filed with the Commission on June 14, 2007)
Amendment No. 1 to Employment Agreement, dated as of May 31, 2007, by and between
Advanced Biotherapeutics, Inc. and Laura Campbell (incorporated herein by reference to
Exhibit 10.21 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Employment Agreement, dated as of September 25, 2000, by and between Advanced
Biotherapeutics, Inc. and Kurt Brunden (incorporated herein by reference to Exhibit 10.22 to the
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on June 14, 2007)
Amendment No. 1 to Employment Agreement, dated as of May 31, 2007, by and between
Advanced Biotherapeutics, Inc. and Kurt Brunden (incorporated herein by reference to
Exhibit 10.23 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of September 25, 2000, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc. and Kurt Brunden (incorporated herein by reference
to Exhibit 10.24 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108)
filed with the Commission on June 14, 2007)
Employment Agreement, dated as of October 3, 2003, by and between Advanced Biotherapeutics,
Inc. and Robert Deans, Ph.D. (incorporated herein by reference to Exhibit 10.25 to the registrant’s
Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14,
2007)
Amendment No. 1 to Employment Agreement, dated as of May 31, 2007, by and between
Advanced Biotherapeutics, Inc. and Robert Deans (incorporated herein by reference to
Exhibit 10.26 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of October 3, 2003, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc. and Robert Deans (incorporated herein by reference
to Exhibit 10.27 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108)
filed with the Commission on June 14, 2007)
Employment Agreement, dated as of January 1, 2004, by and between Advanced Biotherapeutics,
Inc. and William Lehmann (incorporated herein by reference to Exhibit 10.28 to the registrant’s
Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14,
2007)
Amendment No. 1 to Employment Agreement, dated as of May 31, 2007, by and between
Advanced Biotherapeutics, Inc. and William Lehmann (incorporated herein by reference to
Exhibit 10.29 to the registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed
with the Commission on June 14, 2007)
Non-Competition and Confidentiality Agreement, dated as of September 10, 2001, by and among
Athersys, Inc., Advanced Biotherapeutics, Inc. and William Lehmann (incorporated herein by
reference to Exhibit 10.30 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Form Incentive Agreement by and between Advanced Biotherapeutics, Inc. and named executive
officers, and acknowledged by Athersys, Inc. and ReGenesys, LLC (incorporated herein by
reference to Exhibit 10.31 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Form Amendment No. 1 to Incentive Agreement by and between Advanced Biotherapeutics, Inc.
and named executive officers, and acknowledged by Athersys, Inc. and ReGenesys, LLC
(incorporated herein by reference to Exhibit 10.32 to the registrant’s Current Report on Form 8-K
(Commission No. 000-52108) filed with the Commission on June 14, 2007)

81

Exhibit No.

10.34

10.35*

10.36*

10.37

10.38†

10.39†

10.40

21
23
24
31.1

31.2

32.1

Exhibit Description

Securities Purchase Agreement, dated as of June 8, 2007, by and among Athersys, BTHC VI, Inc.
and Investors (as defined therein) (incorporated herein by reference to Exhibit 10.33 to the
registrant’s Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission
on June 14, 2007)
Exclusive License Agreement, dated as of May 17, 2002, by and between Regents of the
University of Minnesota and MCL LLC, assumed by ReGenesys, LLC through operation of
merger on November 4, 2003 (incorporated herein by reference to Exhibit 10.34 to the registrant’s
Current Report on Form 8-K (Commission No. 000-52108) filed with the Commission on June 14,
2007)
Strategic Alliance Agreement, by and between Athersys, Inc. and Angiotech Pharmaceuticals, Inc.,
dated as of May 5, 2006 (incorporated herein by reference to Exhibit 10.35 to the registrant’s
Current Report on Form 8-K/A (Commission No. 000-52108) filed with the Commission on
October 9, 2007)
Amendment No. 1 to Cell Line Collaboration and License Agreement, dated as of January 1,
2006, by and between Athersys, Inc. and Bristol-Myers Squibb Company (incorporated herein by
reference to Exhibit 10.36 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on June 14, 2007)
Consulting Agreement, by and among Athersys, Inc., Advanced Biotherapeutics, Inc. and Dr. Kurt
Brunden, dated as of July 23, 2007 (incorporated herein by reference to Exhibit 10.13 to the
registrant’s Quarterly Report on Form 10-Q (Commission No. 000-52108) filed with the
Commission on August 17, 2007)
Form Indemnification Agreement for Directors, Officers and Directors and Officers (incorporated
herein by reference to Exhibit 10.1 to the registrant’s Current Report on Form 8-K (Commission
No. 000-52108) filed with the Commission on August 6, 2007)
Advisory Agreement, dated as of May 24, 2007, by and between Halter Financial Group, L.P. and
Athersys, Inc. (incorporated herein by reference to Exhibit 10.40 to the registrant’s Registration
Statement on Form S-1/A (Registration No. 333-144433) filed with the Commission on
September 12, 2007).
List of Subsidiaries
Consent of Ernst & Young LLP, Independent Registered Public Accounting Firm
Power of Attorney
Certification of Gil Van Bokkelen, Chairman and Chief Executive Officer, pursuant to SEC
Rules 13a-14(a) and 15d-14(a) adopted pursuant to Section 302 of the Sarbanes-Oxley Act of
2002.
Certification of Laura Campbell, Vice President of Finance, pursuant to SEC Rules 13a-14(a) and
15d-14(a) adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
Certification of Gil Van Bokkelen, Chairman and Chief Executive Officer, and Laura Campbell,
Vice President of Finance, pursuant to 18 U.S.C. Section 1350, adopted pursuant to Section 906 of
the Sarbanes-Oxley Act of 2002.

* Confidential treatment requested as to certain portions, which portions have been filed separately with the

Securities and Exchange Commission

† Indicates management contract or compensatory plan, contract or arrangement in which one or more direc-

tors or executive officers of the registrant may be participants

82

EXHIBIT 31.1

CERTIFICATIONS

I, Gil Van Bokkelen, certify that:

1. I have reviewed this annual report on Form 10-K of Athersys, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit

to state a material fact necessary to make the statements made, in light of the circumstances under which such
statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this
report, fairly present in all material respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining
disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e) and internal
control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant
and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and
procedures to be designed under our supervision, to ensure that material information relating to the
registrant, including its consolidated subsidiaries, is made known to us by others within those entities,
particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over

financial reporting to be designed under our supervision, to provide reasonable assurance regarding the
reliability of financial reporting and the preparation of financial statements for external purposes in
accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in
this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end
of the period covered by this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting
that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the
case of an annual report) that has materially affected, or is reasonably likely to materially affect, the
registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of
internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s
board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control

over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record,
process, summarize and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a

significant role in the registrant’s internal control over financial reporting.

/s/ GIL VAN BOKKELEN
Gil Van Bokkelen
Chief Executive Officer and
Chairman of the Board of
Directors

March 14, 2008

EXHIBIT 31.2

CERTIFICATIONS

I, Laura K. Campbell, certify that:

1. I have reviewed this annual report on Form 10-K of Athersys, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit

to state a material fact necessary to make the statements made, in light of the circumstances under which such
statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this
report, fairly present in all material respects the financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining
disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e) and internal
control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant
and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and
procedures to be designed under our supervision, to ensure that material information relating to the
registrant, including its consolidated subsidiaries, is made known to us by others within those entities,
particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over

financial reporting to be designed under our supervision, to provide reasonable assurance regarding the
reliability of financial reporting and the preparation of financial statements for external purposes in
accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in
this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end
of the period covered by this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting
that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the
case of an annual report) that has materially affected, or is reasonably likely to materially affect, the
registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of
internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s
board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control

over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record,
process, summarize and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a

significant role in the registrant’s internal control over financial reporting.

March 14, 2008

/s/ LAURA K. CAMPBELL

Laura K. Campbell
Vice President, Finance

EXHIBIT 32.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of Athersys, Inc. (the “Company”) on Form 10-K for the year
ended December 31, 2007, as filed with the Securities and Exchange Commission on the date hereof (the
“Report”), each of the undersigned officers of the Company certifies, pursuant to 18 U.S.C. Section 1350, as
adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to such officer’s knowledge:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities

Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial
condition and results of operations of the Company as of the dates and for the periods expressed in the
Report.

/s/ GIL VAN BOKKELEN
Name: Gil Van Bokkelen
Title:

Chairman and Chief Executive Officer

/s/ LAURA K. CAMPBELL

Name: Laura K. Campbell
Title: Vice President, Finance

Date: March 14, 2008

The foregoing certification is being furnished solely pursuant to 18 U.S.C. Section 1350 and is not being

filed as part of the Report or as a separate disclosure document.

[This Page Intentionally Left Blank]

Stock Performance Graph 

Notwithstanding any statement to the contrary in any of our previous of previous or future filings 
with  the  Securities  and  Exchange  Commission,  the  following  information  relating  to  the  price 
performance  of  our  common  stock  shall  not  be  deemed  “filed”  with  the  Commission  or  “soliciting 
material” under the Securities Exchange Act of 1934 and shall not be incorporated by reference into any 
such filings. 

The  following  graph  shows  a  comparison  from  June  12,  2007  (the  date  our  common  stock 
commenced  trading  after  the  merger)  through  December  29,  2007  of  cumulative  total  return  for  the 
NASDAQ Composite Index (NASDAQ), our common stock (ATHX) and the NASDAQ Biotechnology 
Index  (NBI).    Such  returns  are  based  on  historical  results  and  are  not  intended  to  suggest  future 
performance.  Data for the NASDAQ Composite Index and the NASDAQ Biotechnology Index assumes 
reinvestment  of  dividends.    We  have  never  paid  dividends  on  our  common  stock  and  have  no  present 
plans to do so. 

Assumes $100 was invested on 6/12/07 in the NASDAQ composite index, NASDAQ biotech index or 
our common stock. 

[This Page Intentionally Left Blank]

Directors and 
Corporate Ofﬁcers

Management

Board of Directors

Gil Van Bokkelen, Ph.D.
Chairman and CEO

Gil Van Bokkelen, Ph.D.
Chairman & CEO

John Harrington, Ph.D.
Executive Vice President and 
Chief Scientiﬁc Ofﬁcer

John Harrington
Executive Vice President and 
Chief Scientiﬁc Ofﬁcer

William (B.J.) Lehmann Jr., J.D.
President & Chief Operating Ofﬁcer

George M. Milne, Ph.D.
Retired

Robert Deans, Ph.D.
Senior Vice President, 
Regenerative Medicine

Laura Campbell, C.P.A.
Vice President, Finance

William Mulligan
Managing Partner, 
Primus Venture Partners

Michael Sheffery, Ph.D.
General Partner, 
OrbiMed Advisors

Jordan Davis
Managing Partner, 
Radius Ventures

Floyd D. Loop, M.D.
Retired

Lorin J. Randall
Financial Consultant

Shareholder
Information

Corporate Headquarters
Athersys, Inc.
3201 Carnegie Ave.
Cleveland, OH 44115-2634
Phone: (216) 431-9900
Fax: (216) 361-9495
www.Athersys.com

Stock Listing
The Company’s common stock
trades on the NASDAQ Capital
Market under the symbol
“ATHX”

Transfer Agent & Registrar
National City Bank
629 Euclid Avenue, Room 635
Cleveland, OH  44114

Independent Auditors
Ernst & Young
Suite 1300
925 Euclid Avenue
Cleveland, OH 44115

Legal Counsel
Jones Day
North Point
901 Lakeside Avenue
Cleveland, OH  44114

Investor Relations
Lisa Wilson
President
In-Site Communications
950 Third Avenue, 9th Floor
New York, NY 10022

3201 Carnegie Avenue
Cleveland, OH 44115-2634

Athersys.com