Pfizer will discontinue development of one of the two investigational rheumatoid arthritis drugs it is working on with Trubion Pharmaceuticals.

The companies decided to halt development of TRU-015 based on poor preliminary results in a Phase IIb study.

The treatment did not meet its primary endpoint of a 20% difference in response compared with a placebo at week 24.

They will, however, continue to develop SBI-087, which had positive results in the Phase II trial.

The Phase II study evaluated the efficacy and safety of both variants of the drug in patients with active rheumatoid arthritis.