FDA Delays Amgen's Denosumab Osteoporosis Drug


The U.S. Food and Drug Administration has delayed approval for denosumab, a new medication for preventing post-menopausal osteoporosis. The regulatory agency is requesting a new clinical program and further information on the post-marketing surveillance program for the drug, which will bear the brand name Prolia. The FDA has also requested an update on all safety data related to denosumab.

The current proposal by Amgen Inc., the company that makes denosumab, is to study more than 5,000 patients treated with Prolia over a period of 10 years. In addition, it has proposed an observational study using healthcare databases that will involve approximately 380,000 women for up to 5 years.

Amgen has also submitted an application for approval for the claim that the drug will treat and prevent bone loss due to hormone ablation therapies used in the treatment of breast and prostate cancer. That application has not yet received a response by the FDA. Currently, there are no approved therapies for bone loss in cancer patients.


A panel of outside advisers urged the FDA in August to reject the medication as a preventive therapy or as a treatment for breast cancer bone loss related to concerns about serious infections seen in some patients and the lack of knowledge of long-term risks associated with the therapy. They did approve use for treatment of postmenopausal osteoporosis and prostate cancer patients.

Osteoporosis is a disease in which bones become fragile and more likely to break. The disease affects nearly eight million women in the United States, and is likely to increase as the population ages. The costs associated with osteoporosis-related fractures are equivalent to those of cardiovascular disease and asthma. It has also been reported that osteoporosis results in more hospital stays than stroke, myocardial infarction, or breast cancer.

The currently approved osteoporosis medications work by slowing the rate of bone resorption without changing the rate of bone formation, which continues and results in a small increase to bone mass. Denosumab will work differently in that it will inhibit a protein called RANK ligand that activates bone-destroying cells called osteoclasts, slowing breakdown of tissue. When approved, the drug will be administered twice yearly subcutaneously at a 60 milligram dose.

Amgen, a biotechnology company based in Thousand Oaks, California, also produces two medications for the treatment of anemia – Aranesp and Epogen. The company will partner with GlaxoSmithKline to jointly market denosumab when it is approved.

Sources Include: Amgen, National Osteoporosis Foundation, and Drugs.com