West Coast Editor

One month away from an FDA panel review, GPC Biotech Inc.'s satraplatin for prostate cancer has become the subject of a $10 million license deal with Yakult Honsha Co. Ltd., for rights in Japan.

Tokyo-based Yakult - which already markets the platinum-based cancer therapy oxaliplatin and invented irinotecan, the standard therapy for colorectal cancer - is paying ¥1.2 billion (US$10 million) to GPC, of Martinsried, Germany, as reimbursement for past expenses related to satraplatin. From this point on, Yakult will pay all development, marketing and sales costs.

"We've put a lot into its development," said Laurie Doyle, director of investor relations and corporate communications for GPC, who estimated the total spending at around $90 million. The deal with Yakult brings undisclosed regulatory milestone payments, along with at least 21 percent royalties on sales in Japan.

Satraplatin, the only platinum drug shown to work in randomized trials against hormone-refractory prostate cancer, also is the only oral drug in the class. Analysts estimate peak sales in the U.S. could reach $500 million. GPC's partner for the drug in Europe is Boulder, Colo.-based Pharmion Corp., which paid $37.1 million up front as part of a deal that could be worth about $270 million. (See BioWorld Today, Dec. 21, 2005.)

The FDA's Oncology Drugs Advisory Committee is slated to take up the new drug application for satraplatin July 24, and the PDUFA date for the agency's priority review is Aug. 15.

The Phase III SPARC (Satraplatin and Prednisone Against Refractory Cancer) trial compared satraplatin plus prednisone to placebo plus prednisone in 950 patients with hormone-refractory prostate cancer. At the American Society of Clinical Oncology meeting earlier this month, GPC and Pharmion said results from SPARC showed satraplatin lowered the risk of disease progression by 33 percent compared to the control group.

"We've got quite a bit still going on with satraplatin," Doyle said, including a Phase II trial with Tarceva (erlotinib, Genentech Inc. and OSI Pharmaceuticals Inc.) against non-small-cell lung cancer.

She did not rule out a co-promotion deal in the U.S. "Certainly the plan is to take the commercialization lead ourselves," Doyle said. "But, were an excellent opportunity to come along, we certainly wouldn't close the door." GPC's marketing group, including a sales force expected to number about 40 reps at launch, is practically built, she added.

Around the start of this year, Spectrum Pharmaceuticals Inc., which licensed satraplatin to GPC in 2002, filed a demand for arbitration against GPC, charging that the company has not used "commercially reasonable efforts" to gain regulatory approval of the product in Japan, and asked to be reimbursed for €9 million (US$12 million) in past development expenses.

GPC, in response, said claims made by Waltham, Mass.-based Spectrum are without merit and denied that it defaulted on any obligation under the licensing agreement. An arbitration panel of three members has been chosen and a hearing will take place next month.

Whether Spectrum could get any of the $10 million is not clear, though "I can say that our agreement with them expressly allows us to recoup development expenses" from partners such as Yakult and Pharmion, Doyle said. In an SEC filing this month, mention of the Spectrum dispute noted that the impact of the arbitration could be "severe, if Spectrum is granted the right to terminate the license."

Satraplatin is GPC's pipeline leader by far. At the Phase I stage is the monoclonal antibody 1D09C3 for leukemia and lymphomas. The company had about $51.5 million in cash and cash equivalents at the end of last year.

GPC's stock (NASDAQ:GPCB) closed Monday at $26.07, down 26 cents, almost twice its 52-week low of $13.42, thanks mainly to favorable news regarding satraplatin in HRPC, where the drug has been shown to help with the disease itself and with related pain.

Final survival data from the SPARC trial are "all we're waiting for now," and those results are due around the end of the year, Doyle said.