Rigel RA drug flunks Phase II trial

Shares of Rigel Pharmaceuticals were hit hard this morning as the company's rheumatoid arthritis drug R788 failed a mid-stage trial in patients who did not respond to at least one biologic treatment. Those given R788 (fostamatinib disodium) did not report significantly higher response rates than the placebo group at three months, causing the drug to miss its efficacy endpoints.

The company noted that the placebo group had unexplained improvement after six weeks and again at three months, which affected the overall trial results. "For this patient population, patients who failed biologic therapies, their bones and joints appear to respond to R788, but the objective and subjective components of the ACR and DAS28 scores are incongruent, mainly because the reported subjective placebo response rates were higher than expected," explained Elliott Grossbard, M.D., chief medical officer for Rigel.

R788 outperformed the placebo in blood tests for inflammation, and in tests for inflammation in bone and the membranes lining joints. Rigel plans to push ahead with development of the drug. "... R788 is well tolerated and its side effects appear generally manageable, and we look forward to planning our Phase III program for R788 with a corporate partner," stated Grossbard.

- see Rigel's announcement
- here's more form Pharmaceutical Processing