Scrutiny Spoils Cell Genesys

Biotech investors looking for the next Dendreon(DNDN) will naturally look at Cell Genesys(CEGE) and its prostate cancer vaccine.

But when you dig into how Cell Genesys is approaching cancer immunotherapy and the clinical data it has collected so far, I think you'll see more questions than definite answers.

Don't forget that the field of cancer vaccines is littered with failures. Dendreon's success offers hope of more future winners, but I'm not ready to put Cell Genesys in that category yet.

Cell Genesys is developing a prostate cancer vaccine known as GVAX. The company is currently enrolling prostate cancer patients in two pivotal phase III trials. Enrollment in the first trial is expected to be completed this year, with data possible in 2009.

It's going to be a good long time, therefore, before we get a definitive answer about GVAX's efficacy (another reason to be cautious). However, in the near term, there is phase II data that has some folks excited about GVAX's potential.

On Tuesday, Cell Genesys announced that 22 prostate cancer patients in the high-dose arm of a phase II trial reported a median survival time of 35 months. Previously, the company had reported a median survival of 26 months in GVAX patients enrolled in an earlier phase II study.