Trubion Pharmaceuticals, Inc (SEATTLE, Washington), a biopharmaceutical company creating a pipeline of product candidates to treat autoimmune disease and cancer, announced it has completed enrollment and dosing of patients in its phase IIb clinical trial of TRU-015, the company's lead Small Modular ImmunoPharmaceutical (SMIPâ„¢) drug candidate for the treatment of rheumatoid arthritis (RA). TRU-015 is a novel single-chain polypeptide targeting CD20 (B-cell depleting) and is engineered for potent ADCC (antibody dependent cellular cytotoxicity) activity and attenuated CDC (complement dependent cytotoxicity) activity.

The randomized, double-blind, placebo-controlled clinical trial is designed to evaluate safety and clinical response rates in patients with RA. The 280 enrolled patients have been randomized into five groups to evaluate the effect of a single infusion of TRU-015 ranging from 200 mg to 1600 mg per patient compared to placebo for a 24-week period. This study will evaluate composite measurements of improvement in disease activity derived from parameters such as tender and swollen joint counts, patient and physician global assessments, patient assessment of pain and disability, and laboratory measures of inflammation as defined by the American College of Rheumatology (ACR). Trubion expects trial results to be reported later in 2007, and it is expected that these results will serve as the basis for a phase III pivotal trial design.

In 2006, the company announced the results of a phase IIa study in RA patients designed to demonstrate proof-of-concept that TRU-015 measurably improves the signs and symptoms of RA. In the first 24 weeks after receiving intravenous infusions of TRU-015, 72% of the subjects experienced a clinical response that is equal to or greater than that required to achieve an ACR 20 response, 28% achieved an ACR 50 response and 14% achieved an ACR 70 response.

In December 2005, the company entered into a collaboration agreement with Wyeth for the development and worldwide commercialization of certain therapeutics, including TRU-015. Trubion is eligible to receive over $800 million in milestone payments from Wyeth as a result of the strategic alliance to codevelop and commercialize Trubion's SMIP immunotherapy technology for inflammatory disease and cancer, in addition to royalties on product sales and copromotion fees. Approximately one third to one half the size of conventional therapeutic monoclonal antibodies, SMIP drugs are engineered to possess the full binding and activity function of a monoclonal antibody and exhibit selective target binding and long in vivo half-lives.

—A. Techman

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