Controversial Pfizer Osteoporosis Drug Receives Mixed Reviews

If Pfizer has its way, the world’s largest drug maker will have approval for a new osteoporosis drug that could bring an estimated $500 million a year.

Approval for the drug, Fablyn (lasofoxifene), was rejected three years ago by the FDA.

An expert panel looking at the drug Monday resulted in nine panel members concluding the benefits outweigh the risk and three saying it did not. One member abstained.

The concerns are that Fablyn raises the risk of death more than a placebo. A risk of developing blood clots has also been observed in the Pfizer drug.

Pfizer says the deaths “appears to be due to an unusually low mortality rate for the placebo group” rather than a problem with the drug.

The panel of experts said the drug offers some benefits for postmenopausal women, but should be limited to those facing a high risk for fracture, stopping short of a clear-cut endorsement.

“We believe the data presented today demonstrates that lasofoxifene offers unique benefits for the treatment of osteoporosis in women at increased risk of fractures.  We will continue to work with FDA on any outstanding questions they may have as a result of today’s discussion,” said spokesman Jack Cox in a statement.

A ruling on Fablyn  should come in October. While the FDA usually follows the expert panel recommendations, this mixed recommendation leaves the drug maker guessing.

Other drugs on the market for osteoporosis include Evista, Reclast, Boniva, Actonel and Fosamax, which led the market until February of this year.  The drugs act like the hormone estrogen without the side effects.

The FDA rejected Fablyn in September 2005 because of concerns that it may cause cancer in the lining of the uterus, according to Pfizer.

The drug also was rejected in January 2006 as a treatment for vaginal atrophy.

The FDA panel found that patients on the 0.5 milligram dose were 41 percent less likely to have vertebrae fractures or of those fractures to worsen.

In a Pfizer study, at the lower dose of 0.25, there was a rise in combined fatalities from all forms of cancer.

"I'm really dismayed that we don't have a head-to-head trial" of Fablyn with other FDA-approved drugs, said panel member Clifford Rosen, a senior scientist at the Maine Center for Osteoporosis to the Wall Street Journal.

A recent study at Children’s hospital in Boston found that 40 percent of children are not getting enough vitamin D to promote healthy bones, which begins in childhood and adolescence. 

The vitamin along with calcium and magnesium are known to fight osteoporosis. #