Rigel's round trip

Rigel Pharmaceuticals Inc. (NASDAQ:RIGL) dropped 40% last week after presenting detailed data on its Phase II trial of rheumatoid arthritis compound R788. The data raised safety concerns, including hypertension, and there was an imbalance in response rates seen in different countries. The last time the stock was trading below $10 was 12 months ago, just prior to the company's announcement that R788 met the primary endpoint of percentage of ACR20 responders compared to placebo in the same study. At the American College of Rheumatology meeting last week, Rigel noted an average increase in blood pressure from baseline in patients on R788 and reported 3 of 49 (6%) and 2 of 47 (4%) cases of mild-to-severe hypertension for the 100 and 150 mg dose groups, respectively. Last December, Rigel reported 2 of 49 (4%) and 0 of 47 cases of moderate-to-severe hypertension. According to Rigel COO Raul Rodriguez, the elevated blood pressure is not a new issue, as it was brought up in prior presentations and investor meetingRodriguez also told BioCentury that he thought last week's selloff was due to a "good deal of misinformation created around the ACR meeting." He pointed to rumors that QTc prolongation was an issue for R788 and said "there's been no QTc signal whatsoever as of today." He said a QTc study is ongoing and still blinded. Additionally, Rigel presented data showing ACR responses in Mexico for both placebo and R788 were higher than at the U.S. sites. "This is not an unprecedented event in clinical trials for rheumatology," CMO Elliott Grossbard said on a conference call. He noted geographic differences were seen in studies of other RA drugs, including Actemra tocilizumab from Roche (SWX:ROG, Basel, Switzerland) and Orencia abatacept from Bristol-Myers Squibb Co. (NYSE:BMY, New York, N.Y.). He noted past speculation that geographic differences could be due to cultural differences in the perception of efficacy that could affect an ACR score, a composite measure that includes patient assessments.Grossbard said detailed data on the Phase II study are expected to be published in about two weeks in Arthritis & Rheumatism. Data from Rigel's ongoing Phase IIb studies of R788 in RA are expected in late summer 2009.The company's shares gained 19% after bottoming out last Tuesday, the day after the ACR presentation. Below are selected events tracked against Rigel's stock price and the BioCentury 100 index over the last 12 months. ...