An experimental drug from Pfizer could benefit certain women with osteoporosis, federal advisers said Monday, despite concerns of side effects.
A Food and Drug Administration panel of experts voted 9-3 that the benefits of Fablyn could outweigh its risks, including blood clots and vaginal bleeding, for some women. The FDA is not required to follow the advice of its advisers, though it often does.
Some panelists said the drug's use should be limited to women at high risk of fractures. Others said the drug should only be used by women who cannot take alternatives, including older drugs like Merck & Co. Inc.'s Fosamax.
Pfizer, the world's largest pharmaceutical maker, has asked the FDA to approve the estrogen-regulating drug for postmenopausal women with osteoporosis, which can cause debilitating bone fractures and thinning.
The panel's positive vote surprised some on Wall Street, who had expressed relatively low expectations for the drug ahead of the meeting.
Citing the negative tone of FDA's safety review issued last week, Rodman and Renshaw analyst Michael King Jr. wrote that "Pfizer will have to do a lot to dance its way past this panel."
Pfizer Inc. shares rose 63 cents, or 3.4 percent, to end the day at $19.14. San Diego-based Ligand Pharmaceuticals rose 35 cents, or 10.9 percent, to $3.56.
Pfizer developed Fablyn using technology from Ligand Pharmaceuticals, which will receive royalty payments and cash if the drug is approved.
Government regulators have already rejected Fablyn once, in 2005, citing concerns it could hasten cancer of the uterus lining. While those specific problems didn't show up in more recent studies, FDA noted higher rates of overall death among women taking the drug.
Pfizer said ahead of the meeting that the increased deaths were due to chance. A majority of panelists said they didn't have enough information to judge what had caused the uptick.
FDA staff said they would weigh that uncertainty carefully as they make their decision on the drug — which is due next month.
"Mortality is a great concern and certainly we'll have to go back and look at it," said Dr. Scott Monroe, FDA's Director for Reproductive and Urologic Products. "What we heard here today was neither a clean-cut 'there's no hope for the drug' or an endorsement."
Pfizer said in a statement it "will continue to work with FDA on any outstanding questions they may have."
Government regulators have been cautious when reviewing drugs to treat menopausal symptoms following problems seen with hormone-replacement therapy. In 2002, a government study of over 16,000 women was halted after showing that those taking hormones had more breast cancers, heart attacks and related problems than nonusers.