Rigel Pharmaceuticals (NASDAQ: [[ticker:RIGL]]), the South San Francisco-based biotech company, reported that its oral pill for rheumatoid arthritis was able to help patients who responded poorly to standard treatment with methotrexate. About two-thirds (67 percent) of patients on a twice-daily 100 milligram dose of fostamatinib (R788) saw at least a 20 percent improvement in the signs and symptoms of rheumatoid arthritis after six months, according to data from a mid-stage trial published in the New England Journal of Medicine. That compares with 35 percent of patients who did that well in the placebo group. London-based pharmaceutical giant AstraZeneca, which licensed the rights to the compound from Rigel, plans to start a pivotal clinical of the drug shortly, in the second half of 2010.