Trubion Pharmaceuticals, Inc (SEATTLE, Washington), a biopharmaceutical company creating a pipeline of protein therapeutic product candidates to treat autoimmune and inflammatory diseases and cancer, announced that its collaboration partner Wyeth Pharmaceuticals, a division of Wyeth, has filed an investigational new drug (IND) application for SBI-087 for rheumatoid arthritis (RA), and clinical trial sites are preparing to enroll patients in a phase I study. In collaboration with Trubion, Wyeth is developing SBI-087 and other CD20-directed products. SBI-087 for RA builds on both companies' clinical experience with Trubion's lead compound, TRU-015, and is based on Trubion's Small Modular ImmunoPharmaceutical (SMIP™) technology. Wyeth intends to pursue clinical evaluation of SBI-087 in systemic lupus erythematosus; an IND filing is expected by the end of 2008.

The phase I SBI-087 dose-escalation clinical trial will evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of a single dose of SBI-087 in patients with RA. Preclinical research suggests that SBI- 087, a fully humanized CD20-directed SMIP, has enhanced potency in B-cell depletion in vivo compared with Rituxan and other CD20-directed therapies.

In addition to SBI-087, Trubion also announced the protocol details and design of a phase IIb study of TRU-015 for patients with RA that the company believes could be supportive of a registration package. The randomized, parallel, double-blind, placebo-controlled, dose regimen-finding study will evaluate the safety and efficacy of 2 dosing regimens administered to ~216 patients with active seropositive RA on a background of methotrexate. The primary outcome measurement will include the American College of Rheumatology (ACR) 50 response measured at 24 weeks. Secondary outcome measurements will be ACR-20, -70, and DAS28 responses. That study is preparing for participant recruitment.

Trubion's current product candidates are novel single-chain protein, or SMIP therapeutics, and are designed using its custom drug assembly technology.