(Adds panel member, company comments)
By Lisa Richwine
ROCKVILLE, Md., July 24 (Reuters) - U.S. regulators should wait for more data before deciding whether to approve GPC Biotech AG’s GPCG.DE proposed prostate cancer pill Orplatna, an advisory panel said on Tuesday in a 12-0 vote.
The committee said it was important to see if patients who took Orplatna in a company trial lived longer than others who got a placebo. GPC officials said it could take another year for that information to be available.
“Survival benefit may well be seen, but I don’t think we see it at the current time,” said Dr. Wyndham Wilson, a panel member and National Cancer Institute researcher.
An interim analysis as of June 15, 2006, showed survival was no better with Orplatna than a placebo, U.S. Food and Drug Administration staff said.
Orplatna, known generically as satraplatin, is the lead product candidate for Germany-based GPC Biotech.
Spectrum Pharmaceuticals Inc. (SPPI.O), which licensed the drug to GPC, has the option to co-promote Orplatna in the United States. Pharmion Corp. PHRM.O owns rights to sell the drug in Europe and some other territories.
The FDA usually follows recommendations from its panels of outside experts. The agency is expected to decide whether to clear Orplatna based on current data by Aug. 15.
The panel vote came after U.S. markets closed. Pharmion shares fell 4.5 percent in after-hours trading, while Spectrum shares dropped 21 percent in light trading after the market closed.
Earlier, GPC shares fell 2.8 percent on Nasdaq before being halted while the panel considered Orplatna. The company’s American Depositary Receipts were not trading after hours.
GPC Chief Executive Bernd Seizinger said the company believed strongly in drug’s potential and was “extremely disappointed” with the panel recommendation. “We will continue to work with the FDA as the agency continues its review,” he said in a statement.
GPC is seeking permission to sell Orplatna for patients with prostate cancer that has stopped responding to prior chemotherapy and resists hormone treatments.
Orplatna is a platinum-based drug that can kill cancer cells. Platinum therapies are commonly used in chemotherapy regimens, but the ones currently on the market must be given intravenously. Orplatna is a pill.
The company studied 950 patients treated with satraplatin or a placebo plus the steroid prednisone.
Orplatna patients in the trial lived a median of 11.1 weeks without their disease getting worse, compared with 9.7 weeks for placebo patients.
But FDA reviewers questioned whether that measurement was an acceptable basis for approval and said there were issues with how disease progression and pain were assessed.
GPC officials said Orplatna clearly helped men with advanced prostate cancer who have no other approved treatment options. They said the drug should be cleared based on current data.
“We are talking about a huge unmet medical need for a painful and debilitating disease ... There is no question satraplatin works. There is evidence of disease control, evidence of symptom contol, and there is evidence of safety,” Dr. Marcel Rozencweig, GPC’s chief medical officer, told the panel.
The company had told the FDA that a final survival analysis could be available by year’s end. But officials said during the meeting that fewer-than-expected patients in the trial were dying, which could delay a final evaluation for about a year.
The interim survival analysis was based on 463 deaths. A total of 700 are needed for a final analysis, FDA staff said.