Rigel Pharmaceuticals, Inc, of South San Francisco, California, announced the start of a phase I double-blind, placebo-controlled trial to evaluate R788, an oral syk kinase inhibitor, in combination with methotrexate in 16 patients with stable rheumatoid arthritis (RA). R788 blocks the activation of mast cells, macrophages, and B cells that promote swelling and an inflammatory response.

Phase I trial results have demonstrated that R788 is well-tolerated and showed acceptable pharmacokinetic properties. In preclinical studies, R788 attenuated the swelling and tissue destruction associated with RA. Rigel reported that the company plans to initiate phase II studies of R788 in 2006.  

Rigel Pharmaceuticals is a clinical-stage, small-molecule drug development company focused on the treatment of inflammatory diseases, cancer, and viral diseases.

— A. Techman