Osteoporosis drug effective but expensive
Treatment would entail two shots a year
A first-of-its-kind osteoporosis drug lowers the risk of bone fractures better than some existing treatments, two studies suggest, and could soon add a more expensive but easier to manage treatment option to the booming market.
Amgen Inc. will stress that only two shots of its genetically engineered denosumab, which could be approved for sale this fall, are needed each year. That’s important because many patients stop taking other drugs due to side effects or frequent dosing.
Wall Street sees denosumab as a potential blockbuster crucial to Amgen. But with many cheaper, treatments, doctors view its expected high cost as a drawback. Genetically engineered drugs, made by altering a cell’s DNA or other genetic material, all cost more than $10,000 a year.
“It’ll find a particular niche where it’ll be used, but I don’t see it as taking over the market,” said Dr. Sundeep Khosla, a Mayo Clinic researcher.
Still, he called the drug a “tour de force of modern molecular medicine” because it is potent and was designed by making antibodies cloned over and over from cells in the lab to block one pathway involved in the how the body naturally breaks down bone cells.
Denosumab would be the first osteoporosis treatment that is such a monoclonal antibody – a type of immune cell cloned from the same parent cell to bind to a specific substance. In this case, it targets a molecule in bones that drives formation of cells called osteoclasts that break down bone, a strategy that greatly reduces bone loss.
The Food and Drug Administration on Tuesday released its review of denosumab, with staff citing concerns about increased rates of skin infections and some tumors. That report comes just ahead of a meeting Thursday when outside advisers will weigh the drug’s safety and effectiveness and recommend whether to approve it.
Denosumab, an injection just under the skin, would have to compete against eight major types of pills and injected medicines, including estrogen and generic and brand-name Fosamax pills, long the market leader.
Most of those must be given more often, with pills swallowed once a day, week or month, a nasal spray inhaled daily, and one injection given daily. But another injection given intravenously is only needed once a year, and estrogen, while out of fashion due to its link to breast cancer, is available in skin patches changed once or twice a week.