FDA Panel Recommends Pfizer’s Osteoporosis Drug For Postmenopausal Women

Fablyn, an experimental drug manufactured by Pfizer Inc. for treatment of osteoporosis, has been determined by the FDA to have health benefits that outweigh its risks. The FDA panel met in Rockville, Maryland and voted 9-3 to recommend the drug for postmenopausal women with osteoporosis.

The FDA rejected Fablyn in September 2005 for the prevention of osteoporosis and then again in January 2006 as a potential treatment for vaginal atrophy due to concerns that the drug may cause cancer in the lining of the uterus. However, after further examination of the safety data, Pfizer, the world’s largest drug maker, re-submitted for approval of the drug for treatment of osteoporosis.

Pfizer's latest data shows that 6.4 percent of placebo patients developed new or worsening fractures within three years compared with 3.8 percent given the Fablyn. However, more women died while taking Fablyn than with a placebo. Pfizer attributes this to a small number of deaths in the placebo group within one region and not to the drug.

The FDA panel was unable to clearly determine if a higher rate of deaths among Fablyn patients represented a true increase over patients given a placebo. Many members agreed that the drug could appeal to some women as an alternative to other therapies that carry their own health risks. The panel also voted 9-2, with two abstentions, that blood clot concerns were no greater for Fablyn than with hormonal drugs already sold for osteoporosis or menopause symptoms.

In a news conference following the panel meeting, Sandra Carson, director of reproductive medicine and infertility at Women and Infants Hospital of Rhode Island, and chairperson for the panel said, “The panel felt that women would benefit by having this drug available to them.”

According to Pfizer, the FDA should make an approval decision regarding the drug Fablyn, also known as lasofoxifene, by October. Although the agency generally follows the recommendations of its advisory panels, it is not required to do so. Pfizer said in a statement, “We believe the data presented today demonstrates that lasofoxifene offers unique benefits for the treatment of osteoporosis in women at increased risk of fractures,” and “We will continue to work with FDA on any outstanding questions they may have as a result of today's discussion.”

Carson said that the FDA advisers generally agreed that women who would benefit most from Fablyn are those with cases of osteoporosis that are already documented, with some panel members stating that the drug should be used only after trying other medications.

Fablyn belongs to a class of drugs known as selective estrogen receptor modulators (SERMs), like Eli Lilly and Company's osteoporosis drug, Evista. Other osteoporosis drugs available on the market include Novartis AG’s Reclast, Roche Holding AG’s Boniva, Proctor and Gamble’s Actonel, and Merck & Company’s Fosamax.

According to the Nation Osteoporosis Foundation, osteoporosis is a disease in which bones become fragile and more likely to break. If not prevented or if left untreated, osteoporosis can progress painlessly until a bone fractures or breaks. Osteoporosis is a major public health threat for an estimated 44 million Americans 50 years of age and older. In the U.S. today, 10 million individuals are estimated to already have the disease.