12-Month Preservation of Beta Cell Function and Favorable Safety Profile with Otelixizumab, an Innovative Type 1 Diabetes Compound Under Development

MONTREAL, CANADA | October 21, 2009 | Tolerx, Inc., a biopharmaceutical company developing novel therapies intended to treat diabetes, other autoimmune diseases and cancer by specifically modulating T-cell activity, today presented dose optimization data from its Phase 2 clinical study of otelixizumab in subjects with type 1 diabetes. Otelixizumab is a targeted T-cell immunomodulator currently being evaluated in DEFEND, a Phase 3 clinical study in subjects with new-onset autoimmune type 1 diabetes. Data from the Phase 2 dose optimization study, which were used to determine the dose in the DEFEND trial, were presented at the International Diabetes Federation’s 20th World Diabetes Congress currently taking place in Montreal, Canada.

In an oral presentation entitled "Otelixizumab – Dose regimen optimization of a humanized aglycosylated anti-CD3 monoclonal antibody in adult subjects with type 1 diabetes mellitus," Dr. Louis Vaickus, Chief Medical Officer at Tolerx, presented preliminary data from the Phase 2 otelixizumab dose optimization clinical study, referred to as TTEDD.

In a previous investigator-sponsored Phase 2 study, a high dose (48-64 mg) of otelixizumab was shown to preserve natural insulin production for up to 48 months after a single course of treatment. Subsequently, Tolerx initiated TTEDD to investigate alternative dosing regimens that would minimize adverse events, while maintaining durable clinical activity. A cumulative dose of 3.1 mg of otelixizumab administered over 8 days was identified as the optimized dose suitable for further evaluation. In TTEDD, this dosing regimen resulted in preservation of beta cell function (as measured by C-peptide, a common marker for endogenous insulin production) for up to 12 months in patients with autoimmune new-onset type 1 diabetes with no observation of significant safety issues.

About the DEFEND Study

DEFEND (Durable Response Therapy Evaluation For Early or New-Onset Type 1 Diabetes) is a randomized, placebo-controlled Phase 3 trial intended to enroll approximately 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 trial 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 will be a measurement of C-peptide. For information about DEFEND, please visit www.DefendAgainstDiabetes.com.

About the TTEDD Study

TTEDD is a non-randomized, open-label Phase 2 study intended to enroll approximately 100 patients, age 18 to 45, with autoimmune type 1 diabetes. The purpose of TTEDD is to optimize several multi-dose regimens of otelixizumab, determine the highest biologically active dose, evaluate biomarkers and surrogates of efficacy, and to evaluate the effects of each multi-dose regimen of otelixizumab against standard safety and efficacy parameters.

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.

SOURCE: Tolerx, Inc.