An FDA advisory committee on Thursday recommended the drug, denosumab, for women being treated for osteoporosis as well as for men experiencing bone loss because of prostate cancer treatment, saying it helps prevent bone fractures.
But in a 12-3 vote, the panel of medical experts did not recommend the drug for use by women as a preventive medicine for the bone-thinning disease or to fight bone loss in women undergoing breast cancer treatment. Before it would be willing to recommend the drug for those uses, the committee said, it would like to see more data on long-term use of the drug.
The FDA is scheduled to make its decision on the drug in October and is not required to follow the committee's recommendations, although it usually does. Amgen hopes to market and sell the drug as Prolia.
The recommendations of the panel, which met in Gaithersburg, Md., were a victory for the Thousand Oaks firm, said Amgen spokeswoman Kerry Beth Daly. "I think it's a very good day for osteoporosis patients."
Amgen said it was planning to bring long-term studies back to the FDA. It said it planned five- and 10-year studies of the drug's use for both osteoporosis and cancer patients, regardless of the agency's October decision.
"Amgen looks forward to collaborating with the FDA to arrive at the best possible approach to make Prolia available to appropriate patients," Roger M. Perlmutter, the company's executive vice president of research and development, said in a statement. There are no drugs on the market to treat bone loss in prostate or breast cancer treatment, Amgen said.
In the U.S. about 10 million people have osteoporosis, and about 34 million more are dealing with low bone density, according to the National Osteoporosis Foundation.
But the FDA probably will go along with its advisory panel this fall, said Craig Gordon, an analyst with investment firm Cowen & Co.
"While the scope of approval was much more limited than the company was hoping for, denosumab . . . can still be potentially a $2-billion-a-year drug," Gordon said.
"The osteoporosis sales numbers, if not approved as a preventative drug by the FDA, will have to come down, but this can still be a blockbuster for Amgen."
The drug is intended mainly for those with osteoporosis, but the company would earn more if it is also approved as a treatment to prevent the disease, he said.
Industry analysts think the drug will be the catalyst for the company's growth and expectations shouldn't change just because of the advisory committee's advice to the FDA, Gordon said.
On Thursday, Amgen shares dropped 2.1%, or $1.30, to close at $60.86. In after-hours trading, the firm's stock fell as low as $60.45 a share. Amgen stock has traded as low as $44.96 and as high as $66.51 in the last year.