Trubion slumps after Pfizer kills lead RA drug program

Shares of Seattle-based Trubion Pharmaceuticals (TRBN) slumped after Pfizer announced that it was dumping the development program for its lead rheumatoid arthritis drug. TRU-015 had been Trubion's first shot at a best-in-class CD20 therapy that could compete with Rituxan. But in a mid-stage clinical trial--in which TRU-015 was combined with methotrexate--the drug failed to provide a statistically superior to the placebo plus methotrexate, which registered an unusually high response.

"Given the higher than usual placebo response, TRU-015 did not meet the internal hurdle for continued development," said Scott C. Stromatt, M.D., senior vice president and chief medical officer at Trubion. "It is evident that the drug has significant biological and clinical activity with no significant safety concerns, but market dynamics dictate that we pursue a differentiated and best-in-class product to bring into Phase III development." 

Pfizer hasn't forsaken Trubion altogether though. The two will continue to collaborate on SBI-087, another CD20 drug which has been touted as an even better program that TRU-015. Trubion's shares slid 11 percent yesterday afternoon.

- see the Trubion release
- here's the story from Reuters