All the action in the prostate-cancer-treatment space has been focused around Dendreon's (NASDAQ:DNDN) Provenge. But GPC Biotech (NASDAQ:GPCB), which reported its first-quater results yesterday, has been quietly moving forward with the next potential treatment for hormone refractory prostate cancer.

GPC is waiting for an FDA regulatory decision on its orally dosed chemotherapy drug, satraplatin. In September of last year, GPC released positive data from a 900-person phase 3 study of the drug; three months ago, the company filed a New Drug Application to receive FDA approval.

With a priority review, the FDA should give a thumbs-up or -down on satraplatin by the drug's August 15 PDUFA date, the deadline for the FDA's decision. But investors should have a better idea on the drug's chances for approval before that date. The FDA's Oncology Drug Advisory Committee will convene to discuss the drug on July 24.

After succeeding on the primary endpoint in its phase 3 study, and showing a strongly statistically significant improvement in progression-free survival, satraplatin should become the first drug approved to treat hormone refractory prostate cancer since Sanofi-Aventis' (NYSE:SNY) Taxotere in 2004.

If approved, satraplatin will initially carry a label indicating its use only as a second-line treatment for prostate cancer. While this may initially curtail sales, it shouldn't be too much of a hindrance in the long run, since oncologists will be interested in trying out a new compound for this indication, and label-expanding trials are still ongoing. GPC plans on a U.S. sales force of around 40 people at the drug's launch.

We'll get a better picture of satraplatin's safety and efficacy profile at the American Society of Clinical Oncology conference in early June. If investors want to know what it takes to get a new prostate cancer treatment approved, they won't have to wait much longer until satraplatin's NDA comes up for review.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has a disclosure policy.