Merck Posts Positive Phase 3 Data For Osteoporosis Drug

Merck reported new positive data from the Phase III trial LOFT investigating odanacatib in postmenopausal women with osteoporosis. The company presented its findings at the American Society for Bone and Mineral Research (ASBMR) Annual Meeting in Houston.

Odanacatib is an investigational selective inhibitor of cathepsin K, an enzyme found in cells responsible for bone resorption. Cathepsin K breaks down the major organic component of bone known as type I collagen. Results from the Long-Term Odanacatib Fracture Trial (LOFT) showed that the drug met its primary endpoint by significantly reducing the risk of three types of osteoporotic fractures versus placebo. Specifically, these are hip, spine, and non-vertebral fractures. Odanacatib also reduced the risk of clinical vertebral fractures as the trial’s secondary endpoint.

Patients who were treated with odanacatib in the trial gained progressive increases over five years in bone mineral density (BMD) at the lumbar spine and total hip. Change in BMD from baseline at five years was 11.2 percent for lumbar spine and 9.5 percent for total hip compared to placebo.

“Despite the important and serious consequences of fractures related to osteoporosis and our ability to identify patients who would benefit from therapy, many patients with osteoporosis are not being treated. There is a need for additional treatment options. The effects of odanacatib on fracture risk from the LOFT study are very encouraging,” said Michael McClung, lead investigator in the LOFT trial and founding director of the Oregon Osteoporosis Center in Portland, Oregon.

In May, Merck announced its intent to pursue marketing approval for odanacatib. However, the company was delayed because of concerns that the drug caused a higher incidence of stroke and irregular heartbeat, which were observed in patients who took odanacatib compared to placebo. Morphea, a type of skin thickening, and fractures in the thigh bone were also observed in a fraction of patients taking odanacatib. Merck has established an adjudication committee or central review team to assess the drug’s side effects and other safety concerns.

The company disclosed its plans to submit a New Drug Application (NDA) in the U.S. next year as well as in the EU and Japan. Analysts project that an approval for odanacatib could bring in $1 billion in annual sales for Merck by 2020.