GPC Biotech (NASDAQ:GPCB) announced its second-quarter financial results earlier in the week, in the shadow of a setback for a promising prospective drug. Last month, in an FDA advisory committee meeting, the panel voted 12-0 to recommend against the approval of GPC's lead drug, prostate cancer treatment satraplatin. Following this meeting, shares of GPC have fallen more than 35%.
The advisory panel recommendation surprised me. Oncology compounds with such strong progression-free survival (PFS) statistics are generally looked upon fondly by the FDA, even without much overall survival data (like Amgen's (NASDAQ:AMGN) Vectibix, for example). The crack in GPC's data set was that the advisory panel got hung up on GPC's use of a non-standard definition of PFS.
A formal PDUFA regulatory review of satraplatin was scheduled to take place Aug. 15, but after the advisory panel recommended that approval of the drug only be granted if overall survival data in its ongoing phase 3 study was positive, GPC withdrew its marketing application.
Formally withdrawing the marketing application, rather than just waiting for the likely approvable letter, was an unusual move. GPC explained on the earnings conference call that it was taking this step to refocus its FDA marketing application on the overall survival data once it is completed. I don't see any advantage to this strategy, since GPC could have gained useful information on any other potential FDA concerns from an approvable letter, then addressed these concerns while waiting for the survival data to come in.
Speaking of the overall survival data, top-line results from the phase 3 study are expected in the next six months. A resubmission of the NDA is guided to occur about a year from now, with a possible PDUFA target date in early 2009.
Pharmion (NASDAQ:PHRM), GPC's European marketing partner, announced in June that the European Union medical authorities had accepted its satraplatin marketing application. Review of this regulatory submission should occur next year.
Interim overall survival data last year showed a trend toward improved survival in satraplatin-treated patients versus placebo. With no other meaningful late-stage pipeline compounds, all eyes will be on GPC's release of the overall survival data next year.
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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool's disclosure policy is fully approved.
