Osteoporosis drug first to build bone that lasts

The Food and Drug Administration on Tuesday approved an osteoporosis drug that represents the first new treatment approach in nearly two decades — a strategy based on a rare gene mutation in people with bones so dense that they never break.

About 10 million people in the United States have osteoporosis. Worldwide, about 200 million people worldwide have brittle bones; 1 in 3 women, and 1 in 5 men, will suffer a fracture because of osteoporosis, often of the hip or spine.

Standard treatments, drugs called bisphosphonates, stop the loss of bone but do not build it. The alternatives, parathyroid hormone and a derivative, build bone but also break it down, limiting the therapeutic effect.

The new drug, romosozumab (brand name Evenity), developed by Amgen in collaboration with Belgian drug company UCB, restores bone without breaking it down, according to the findings of two large clinical trials.

It was approved only for postmenopausal women with a high risk of fracture, and will carry a warning on its label that it may increase the risk of heart attack or stroke, the FDA said.

“This is an extraordinarily important drug,” said Dr. Richard Bockman, chief of the endocrine service at the Hospital for Special Surgery in New York. “It’s a true bone-building drug that takes advantage of the underlying biology of bone.”

The FDA said it was requiring the boxed warning on the drug’s label saying the drug should not be used by people who had a heart attack or stroke in the past year. Doctors should also consider whether to prescribe the drug to patients at high risk for heart attacks and strokes.

The new drug has a striking backstory.

In 1964, researchers began studying a group of Afrikaner patients in South Africa. They were tall and heavy, but not fat. Instead, their bones were large and dense.

Their bones grew so profusely that their heads became distorted: Their jaws were large, and an overgrowth of bone in their skulls impinged upon nerves.

In 2001, scientists reported that all these effects resulted from a single gene mutation. That led researchers to understand how the body controls the building of bone.