Trubion Pharmaceuticals, Inc. (Nasdaq: TRBN) today announced favorable safety and efficacy data following administration of a second course (R2) of re-treatment with 800 mg of TRU-015 for rheumatoid arthritis (RA)

SEATTLE, WA, USA | October 19, 2009 | Trubion Pharmaceuticals, Inc. (Nasdaq: TRBN) today announced favorable safety and efficacy data following administration of a second course (R2) of re-treatment with 800 mg of TRU-015 for rheumatoid arthritis (RA). These data are the latest results from the ongoing open-label re-treatment portion of the Phase 2b (15002) RA study of TRU-015. Pfizer Inc. and Trubion are collaborating on the development of TRU-015 for the treatment of autoimmune and inflammatory diseases, including RA.

Data from the open-label re-treatment phase of the Phase 2b study demonstrate that repeat administration with TRU-015 is generally well-tolerated and results in sustained improvement in the signs and symptoms of RA. Results were presented at the 2009 American College of Rheumatology (ACR)/Association of Rheumatology Health Professionals (AHRP) Annual Scientific Meeting in Philadelphia. A copy of the poster is available in the investor section of Trubion’s website (http://investors.trubion.com/index.cfm).

TRU-015 is Trubion’s lead Small Modular Immunopharmaceutical (SMIP) product candidate directed against CD20+ B-cells.

The Phase 2b trial is a double-blind, placebo-controlled, randomized study that is designed to evaluate the safety, tolerability, pharmacodynamics (PD), pharmacokinetics (PK) and clinical activity of repeat doses of TRU-015. Of the 276 original patients who began the study, 240 (204 of whom were rheumatoid-factor positive, or RF+) entered the first open-label re-treatment portion (R1) of the trial. Trubion announced the first course of re-treatment data from this study at the 2009 EULAR Annual Meeting in June 2009.

A total of 226 patients from R1 were enrolled in the second re-treatment portion (R2) of the trial. At 24 weeks after the second re-treatment course, subjects in the group that had received 800 mg of TRU-015 in the initial treatment and re-treatments R1 and R2 achieved ACR 20, 50 and 70 response rates of 72%, 39% and 21%, respectively. Results were similar to the response rates achieved in R1 (70%, 40% and 23%, respectively).

Numeric reductions in the Disease Activity Score 28 (DAS28), the Health Assessment Questionnaire (HAQ), and C-reactive protein (CRP) seen at the end of the double-blind treatment and first re-treatment periods were maintained or continued to improve during the open-label re-treatment period.

Infusions were generally well-tolerated and no patient experienced a serious adverse event on the day of infusion. Eight patients (3.5%) enrolled in the trial experienced serious adverse events during the second re-treatment period. This is similar to observations made during the initial double-blind phase of the study (placebo 2%, 800 mg group 2%) and R1 (4%).

"We have now administered more than 1,300 doses of TRU-015 over four and a half years and continue to see positive and sustained results in RA patients. This reinforces our belief that TRU-015 could represent a differentiated treatment option when compared to other offerings on the market or in development," said Peter Thompson, M.D., FACP, president, CEO and chairman of Trubion. "We believe a key to this differentiation should include data demonstrating both initial improvement in signs and symptoms and sustained improvement following multiple courses of re-treatment."

About Trubion

Trubion is a biopharmaceutical company that is creating a pipeline of novel protein therapeutic product candidates to treat autoimmune and inflammatory diseases and cancer. The Company’s mission is to develop a variety of first-in-class and best-in-class product candidates, customized for optimal safety, efficacy and convenience that it believes may offer improved patient experiences. Trubion’s current product candidates are novel single-chain protein, or SMIP, therapeutics, and are designed using its custom drug assembly technology. Trubion’s product pipeline includes CD20-directed SMIP therapeutics such as TRU-015 and SBI-087 for autoimmune and inflammatory diseases, developed under the Company’s Pfizer collaboration. Trubion’s product pipeline also includes TRU-016, a novel CD37-targeted therapy for the treatment of B-cell malignancies developed under the company’s Facet Biotech collaboration. In addition to Trubion’s current clinical stage product pipeline, the Company is also developing its multi-specific SCORPION technology, both for targeting cell-surface molecules like CD79b and HLA-DR, as well simultaneously neutralizing soluble ligands like TNF and IL-6. More information is available in the investors section of Trubion’s website: http://investors.trubion.com/index.cfm.

SOURCE Trubion Pharmaceuticals, Inc.