FDA Approves Injectable Osteoporosis Drug

Primary-care doctors now have a new—and potentially more convenient—tool to fight the bone disease osteoporosis.

On Tuesday the Food and Drug Administration (FDA) approved a new drug, Prolia (denosumab), to promote bone strength and prevent fractures in postmenopausal women with osteoporosis who are at high risk.

Women at high risk for fractures include those who have already suffered an osteoporosis-related fracture or who haven’t had success with other osteoporosis treatments. Roughly half of all women over age 50 will experience an osteoporosis-related fracture in their lifetime, according to the National Institutes of Health.

Prolia, the first osteoporosis drug of its kind, works by blocking a type of cell that breaks down bone. Unlike most osteoporosis drugs, which come in a pill or are delivered through a skin patch, Prolia is injected by a doctor every six months. 'It’s always wonderful for clinicians and patients to have more options,” says Ethel Siris, MD, the director of the Osteoporosis Center at Columbia University Medical Center, in New York. “It’s a very potent agent and it is pretty clear that the reduction in fracture risk is quite robust.”

Dr. Siris was one of the researchers on a key study of nearly 8,000 postmenopausal women with osteoporosis that served as the basis for the FDA’s approval.

During the three-year study—which was funded by the drug’s manufacturer, Amgen—the women who took Prolia were less likely than a placebo group to experience spine, hip, and other bone fractures. Roughly 2% of the women in the Prolia group suffered a spine fracture, for instance, compared to about 7% in the placebo group. (Dr. Siris, the past president of the National Osteoporosis Foundation, has served on a paid advisory board for Amgen.)

Prolia isn’t the first injectable osteoporosis drug. Two bisphosphonatemedications, Reclast and Boniva, are delivered intravenously in a doctor’s office. Two other drugs, Forteo and Miacalcin, require self-injections every day and every other day, respectively.

Prolia is a new type of injectable drug, however. It’s the first biologic medication to be approved for the treatment of postmenopausal osteoporosis. Biologics, which are genetically engineered versions of human proteins (rather than synthetic chemicals), are also used to treat conditions such as rheumatoid arthritis and psoriasis.