A class action lawsuit has been filed in the United States District Court for the Northern District of California on behalf of purchasers of Rigel Pharmaceuticals, Inc. securities during the period between December 13, 2007 and October 27, 2008 (the “Class Period”), including all persons who acquired the common stock of Rigel pursuant and/or traceable to a false and misleading registration statement and prospectus (collectively, the “Registration Statement”) issued in connection with the Company’s February 2008 secondary offering (the “Offering”). The complaint charges Rigel, certain of its officers and directors and the underwriters of the Offering with violations of the Securities Exchange Act of 1934 and the Securities Act of 1933. Rigel is a clinical-stage drug development company.

The complaint alleges that Rigel was developing a new drug, R788, for the treatment of rheumatoid arthritis. On December 13, 2007, Rigel issued a press release, which was attached as an exhibit to a Form 8-K filed with the SEC, and held a conference call touting the positive summary results of a then-recently-completed clinical trial of R788 in 189 patients in the U.S. and Mexico (the “Study”). In response to the announcement of the summary results of the Study, Rigel’s common stock price more than tripled in one day, from $8 per share to $25.95. On January 24, 2008, Rigel filed the Registration Statement for its offering of common stock, which incorporated by reference the December 13, 2007 Form 8-K. On February 6, 2008, Rigel consummated the Offering, selling five million shares of common stock at a price of $27 per share for proceeds of $135 million. Then, on October 27, 2008, Rigel presented the full results of the Study at a meeting of the American College of Rheumatology and on an investor conference call. Those results contained adverse information omitted from the Company’s December 13, 2007 press release and Form 8-K, as well as from the Registration Statement and subsequent presentations. When this adverse information about the Study’s results was finally disclosed, Rigel’s stock price plunged 38% in a single day, from $14.41 to $8.84.

According to the complaint, the true facts which defendants failed to disclose were: (a) patients in Mexico had higher response rates in both the placebo and treated arms than the U.S. patients, which may have contributed disproportionately to the overall reported benefit observed at the higher doses; (b) R788 caused an increase in average blood pressure which could signal an increase in cardiovascular risk, the mechanism that caused the increase was not well understood and the increase in blood pressure could be a stumbling block for some pharmaceutical companies that were considering licensing the drug; and (c) patients in the Study taking R788 experienced increased liver enzymes compared to patients taking the placebo.

If you are a current shareholder or purchased shares between December 13, 2007 and October 27, 2008 and would like to discuss your options of exercising your rights as a shareholder, please contact us.