Cancer-Drug Research Leaks Sink Genentech but Buoy ImClone

Updated from 2:04 p.m. EDT

Genentech(DNA Quote) shares were hammered Thursday after research abstracts prepared for the upcoming annual meeting of the American Society of Clinical Oncology were leaked.

ImClone Systems (IMCL Quote) shares were up strongly after positive indications for its cancer drug, Erbitux, were noted in another leaked abstract.

The initial buzz: Some are reading safety issues into Genentech's experimental cancer drug, Avastin, after seeing the abstracts, according to sources. Some patients given Genentech's Avastin as part of a phase II trial are apparently having problems with bleeding and blood clots. Wall Street traders have proved quick to react negatively to the preliminary leaked results, but it is not yet clear how significant these safety issues are, according to a hedge fund manager with access to the abstracts. ...