Tolerx Completes Enrollment in DEFEND-1, A Phase 3 Type 1 Diabetes Study With Otelixizumab

CAMBRIDGE, Massachusetts, January 7 - Tolerx, Inc., today announced the completion of patient enrollment in its
Phase 3 clinical study DEFEND-1, which is evaluating the safety and efficacy
of otelixizumab, a targeted T cell immunomodulator, in patients with
new-onset autoimmune type 1 diabetes.

The DEFEND-1 (Durable Response Therapy Evaluation For Early or New-Onset
Type 1 Diabetes) study enrolled 240 patients, aged 12-45 years with newly
diagnosed autoimmune type 1 diabetes. The DEFEND-1 study is investigating the
ability of otelixizumab to preserve beta cell function, which may reduce the
risk of both short- and long-term complications of the disease. Patients will
be monitored during the 12-month follow-up period and c-peptide levels (a
surrogate measure of beta cell function) will be measured as the primary
endpoint. Secondary endpoints will evaluate the patient's ability to maintain
excellent glycemic control as measured by HbA1c levels and the amount of
daily injected insulin required.

Dr. Paolo Pozzilli, Professor of Endocrinology & Metabolic Diseases at
the University Campus Bio-Medico in Rome, Italy, and a DEFEND-1 investigator
commented: "Reaching full enrollment in DEFEND-1 is a major accomplishment
for the type 1 diabetes community and furthers the development of innovative
immunomodulating therapies for our patients. We will continue to work with
Tolerx to further otelixizumab's clinical development and to validate its
promise of beta cell preservation in new-onset autoimmune type 1 diabetes
patients."

Peter A. Gottlieb, MD, Associate Professor of Pediatrics and Medicine at
the Barbara Davis Center at the University of Colorado at Denver, known for
his involvement in many types of clinical trials for the prevention and
treatment of diabetes, noted that, "The continuous otelixizumab dose regimen
optimization efforts have been a major translational research focus. These
important research efforts are enabling us, in the DEFEND development
program, to evaluate the potential ability of otelixizumab to provide a
long-term immunologic remission after a short course of therapy. If
successful in the clinic, this would be a significant step forward."

Tolerx also announced today its intention to conduct a second
confirmatory Phase 3 study of otelixizumab in new-onset autoimmune type 1
diabetes. Further details of the design and timing of the study, to be named
DEFEND-2, will be forthcoming.

"The on-time completion of patient enrollment in DEFEND-1 represents a
major milestone for Tolerx," said Dr. Douglas J. Ringler, President and Chief
Executive Officer of Tolerx. "We are very grateful for the dedication of the
patients, their caregivers and our clinical trial investigators for making it
possible to reach our enrollment target. As part of our clinical development
program to reach regulatory approval for otelixizumab, we will now quickly
transition to the launch of DEFEND-2, a confirmatory study, to maintain
enrollment momentum and enthusiasm generated to date in the type 1 diabetes
community."

About the DEFEND-1 Study

DEFEND-1 is a randomized, placebo-controlled Phase 3 study that has
achieved its target enrollment of 240 patients, age 12 to 45, with newly
diagnosed autoimmune type 1 diabetes. DEFEND is being conducted at over 100
study centers throughout Europe and North America. The study is designed to
evaluate whether a single course of otelixizumab, administered not more than
90 days after the initial diagnosis of autoimmune type 1 diabetes, will
preserve beta cell function as measured by c-peptide, a surrogate measure of
beta cell function. The primary endpoint is measurement of c-peptide. For
more information about DEFEND, please visit www.DefendAgainstDiabetes.com.

About Type 1 Diabetes

Diabetes (medically known as diabetes mellitus) is the name given to
disorders in which the body has difficulty regulating its blood glucose
(sugar) level. There are two major types of diabetes: type 1 and type 2. Type
1, previously known as juvenile diabetes or insulin-dependent diabetes, is a
disorder of the body's immune system. In type 1 diabetes, the immune system
attacks and destroys the insulin-producing beta cells in the pancreas. As a
result of the decrease in endogenous (natural) insulin production, patients
must monitor their glucose levels frequently and administer insulin regularly
to control their blood glucose levels.

About Otelixizumab

Otelixizumab is a targeted T cell immunomodulator being developed for the
treatment of type 1 diabetes and other autoimmune diseases. Otelixizumab
targets CD3, a T lymphocyte receptor involved in normal cell signaling.
Otelixizumab has not yet been approved for marketing. Data suggest that the
antibody may work in patients with type 1 diabetes who have residual beta
cells by blocking the function of effector T cells that mistakenly attack and
destroy insulin-producing beta cells, while stimulating regulatory T cells
that are understood to protect against effector T cell damage, thus
preserving the beta cells' ability to make insulin.

About Tolerx

Tolerx, Inc., a world leader in the understanding of T cell function, is
developing novel therapies intended to treat autoimmune diseases, diabetes,
and cancer by specifically modulating T-cell activity. The company's pipeline
includes its lead candidate, otelixizumab, a targeted T-cell immunomodulator
partnered with GlaxoSmithKline in Phase 3 development for the treatment of
type 1 diabetes; a Phase 1 candidate, MTRX1011A, an anti-CD4 antibody that is
being developed in collaboration with Genentech, Inc. for the treatment of
autoimmune indications; and two pre-clinical candidates, TRX518 and TRX385,
that enhance immune responses and are being evaluated for potential benefit
in the treatment of cancer, chronic viral diseases, and as vaccine adjuvants.
Tolerx is a privately held company headquartered in Cambridge, MA USA. For
more information, please visit www.tolerx.com.

Jessica Johnson of Tolerx, Inc., +1-617-452-1356