BETHESDA, Md--The Oncologic Drug Advisory Committee (ODAC) has voted not to recommend that the Food and Drug Administration approve Metaret (suramin hexasodium for injection, Parke-Davis) for the treatment of hormone-refractory prostate cancer.
The 10-to-0 vote against Metaret followed presentation by Parke-Davis of a single randomized trial comparing the drug plus hydrocortisone(Drug information on hydrocortisone) in 228 patients against placebo plus hydrocortisone in 230 patients.
The company contends that the results show Metaret to be superior to placebo in pain response (42% vs 28%), narcotic analgesics use (32.4% vs 54.8%), and median time to progression (99 days vs 44 days). Mean survival was 279 days for the treatment arm and 302 for the placebo arm. The FDA put the median time to progression at 86 days and 85 days, respectively.
Both the FDA and committee members expressed concern about the study because many of the endpoints reported either were not in the protocol or had their criteria changed after the study was completed. In addition, FDA reviewer Judy Chiao, MD, said that her analysis of the safety data indicated that Metaret carried a "nonnegligible risk for severe side effects and death."
The panel expressed a lack of confidence in the credibility of the study results and decided, in separate unanimous votes, that the trial failed to demonstrate a clinically meaningful pain response for Metaret or an acceptable safety profile for the efficacy results obtained.
"We have to make our decision on the basis of data," said Derek Raghavan, MD, PhD, of the University of Southern Californias Norris Comprehensive Cancer Center. "This may be a drug that has some activity, but based on the data presented today, it does not."