Rigel Shares Tank on Arthritis Data (Update)

Updated from Monday, Oct.27

Shares of Rigel (RIGL Quote) took a beating Monday, as the company presented data for experimental arthritis treatment R788.

Shares were down 38% in late-afternoon trading Monday on a combination of heightened safety concerns and newly evident geographic disparity in data from the phase IIa study. Analysts said Tuesday morning that the selloff may be overdone and the risks manageable, but clipped price targets to reflect increased risk.

Patients receiving both R788 and a placebo did better in Mexico than patients in the U.S. Also weighing on shares, there appeared to be an increase in blood pressure, or hypertension, in patients dosed with R788, although hypertension is transient and goes away when the drug is stopped. ...