Tolerx announced the presentation of preclinical research describing the mechanism of action of otelixizumab at the 46th Annual Meeting of the European Association for the Study of Diabetes (EASD)

STOCKHOLM, SWEDEN | September 23, 2010 | Tolerx, Inc., a biopharmaceutical company developing novel therapies to treat autoimmune diseases and cancer by modulating T cell activity, today announced the presentation of preclinical research describing the mechanism of action of otelixizumab at the 46th Annual Meeting of the European Association for the Study of Diabetes (EASD). In addition, Tolerx also announced that the first European patient was enrolled in DEFEND-2, a confirmatory Phase 3 clinical trial evaluating otelixizumab in autoimmune new-onset type 1 diabetes.

"We are very pleased to enroll the first European patient in the DEFEND-2 study, because the European diabetes community and patients are a critical component of DEFEND-2. We look forward to continued patient enrollment in both the U.S. and Europe in this Phase 3 clinical trial," said Dr. Lou Vaickus, Chief Medical Officer of Tolerx. "We are also delighted to share our recent research findings at EASD using a model of human T cell reactivity in which a dual mechanism of action of otelixizumab is suggested, a finding which may be of importance in our Phase 3 type 1 diabetes studies."

The in vitro research presented at EASD demonstrated that otelixizumab affects two important T cell subsets which may be critical for its effect in vivo in type 1 diabetes. In this model system that employs the mixed lymphocyte reaction (MLR), otelixizumab caused a simultaneous decrease in the growth of antigen-specific T killer/effector cells while enhancing the growth of regulatory T cells. This differential effect was most pronounced at lower doses. The Tolerx data appeared in a poster presentation at EASD (Poster # 443), entitled "Otelixizumab differentially modulates human regulatory and non-regulatory T cells."

The new research findings support existing data suggesting that otelixizumab may work in patients with new-onset type 1 diabetes by blocking the function of T killer/effector cells that mistakenly attack and destroy insulin-producing beta cells, while simultaneously stimulating T regulatory cells that are thought to protect against future T killer/effector destruction. Clinical data from the recently completed DEFEND-1 Phase 3 study and the ongoing DEFEND-2 confirmatory Phase 3 study will be evaluated in light of these new findings to determine whether this dual effect of otelixizumab is consistent with results from patients who have received otelixizumab.

About DEFEND-2

DEFEND-2 (Durable-Response Therapy Evaluation For Early or New-Onset Type 1 Diabetes) is a randomized, placebo-controlled confirmatory Phase 3 trial designed to enroll up to 365 patients, age 12 to 45, with newly diagnosed autoimmune type 1 diabetes. DEFEND-2 is being conducted at more than 200 sites in North America and Europe. Building on DEFEND-1, the DEFEND-2 clinical trial similarly evaluates the efficacy and safety of otelixizumab in an additional study population of patients age 12 to 45 with new-onset type 1 diabetes. In the confirmatory study, otelixizumab is administered as a single course, given not more than 90 days after the initial diagnosis of autoimmune type 1 diabetes. The primary endpoint is a measurement of C-peptide, a surrogate measure of beta cell function that has been recommended by the U.S. Food and Drug Administration (FDA) and the American Diabetes Association (ADA), at 12 months after dosing. Maintenance of beta cell function has been associated with improved glycemic control (HbA1c levels), fewer hypoglycemic events, fewer hyperglycemic excursions, and a reduction in long-term disease complications in established type 1 diabetes patients, as referenced in the Diabetes Control and Complications Trial (DCCT).

For additional information about DEFEND-2, 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 involving 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 in Phase 3 development for the treatment of type 1 diabetes that is partnered with GlaxoSmithKline. TRX1, a Phase 1 candidate, is a nonlytic anti-CD4 antibody that is being developed for the treatment of aberrant or untoward immune responses. The company also has three preclinical candidates, TRX518, TRX585 and TRX385, that enhance immune responses and as such are being evaluated for potential benefit in the treatment of cancer and chronic infections. Tolerx is a privately held company headquartered in Cambridge, MA, USA. For more information, please visit www.tolerx.com.

SOURCE: Tolerx