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
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
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."