FDA panel rejects Warner prostate cancer drug
Tuesday September 1, 1:03 pm Eastern Time
BETHESDA, Sept 1 (Reuters) - A U.S. Food and Drug Administration advisory panel voted unanimously on Tuesday against approving Warner-Lambert Inc.'s (WLA - news) Metaret drug for prostate cancer.
The panel said that the drug did not work against the cancer, but said that it did relieve pain. The FDA generally follows its panels' advice.
In voting against approval, panel members said they were not sure which patients would benefit from Metaret, noting that only those with the mildest pain had some improvement in the main Warner-Lambert study.
''The patients who seem to be in most need of help miss out,'' said panelist Derek Raghavan of the University of Southern California.
In the study, 42 percent of the 228 patients taking Metaret had less pain, compared with only 28 percent of a similar number of patients taking placebo. The improvement lasted an average 240 days, said Michael Slichenmyer, senior director of oncology research at Warner-Lambert's Parke-Davis division.
The drug also halved narcotic use, and delayed disease progression, said Slichenmyer.
But the FDA said Metaret only modestly decreased pain and narcotic use, and only in patients who had mild pain at the start.
Prostate cancer, the second leading cause of cancer death in U.S. men, kills 40,000 men a year. About 5 percent of the 244,000 men diagnosed each year in the United States have advanced disease.
Those men have severe pain and require increasing doses of narcotics. Survival is only about two to three years.
Warner-Lambert could not say whether its drug, known generically as suramin, increased survival, partly because almost 70 percent of patients switched from placebo to suramin before the study ended.
Metaret has been around since the 1920s, when it was first used as an anti-parasite drug.
It has never been sold in the United States, but in the 1980s, the National Cancer Institute discovered that the drug might have anti-tumor effects. Warner-Lambert jointly developed Metaret with the NCI.
More study has shown that Metaret inhibits the function of certain growth factors that are thought to be involved in pain, and that it also may block growth of capillaries that feed tumor growth.
The most common side effects were rash, swelling, and weakness. Warner-Lambert said the effects were mostly mild, noting that only twenty-four Metaret patients dropped out of the study.
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