Merck's Odanacatib Reduced Fracture Risk In Postmenopausal Osteoporosis
By Cyndi Root
Merck announced in a press release that data from a Phase III trial of odanacatib in postmenopausal women with osteoporosis met its primary endpoint of reducing fractures. The company presented the results on the cathepsin K inhibitor at the American Society for Bone and Mineral Research (ASBMR) Annual Meeting in Houston, Texas. Merck plans to use the data to support its New Drug Application (NDA) to the Food and Drug Administration (FDA) in 2015. Dr. Keith Kaufman, VP of Clinical Research in the Diabetes and Endocrinology unit at Merck, said, “Merck believes the currently available data support a favorable benefit/risk profile for odanacatib.”
Odanacatib
Odanacatib is an investigational cathepsin K inhibitor, the primary enzyme in the osteoclasts that digests proteins during bone resorption. Inhibiting cathepsin K interferes with bone loss, restoring a balance in bone remodeling, allowing increases in Bone Mineral Density (BMD). Merck is preparing applications for the once-weekly, oral treatment for the FDA, the European Medicines Agency (EMA), and the Ministry of Health, Labor, and Welfare in Japan.
Odanacatib Phase III Study
In the Phase III study comparing odanacatib to a placebo, the Long-Term Odanacatib Fracture Trial (LOFT) trial, odanacatib significantly reduced the risk of osteoporotic hip, spine, and non-vertebral fractures. Michael McClung, M.D., LOFT leader and founding director of the Oregon Osteoporosis Center in Portland, Oregon, said, “The effects of odanacatib on fracture risk from the LOFT study are very encouraging.”
The trial of 16,713 women over the age of 65 was conducted at 367 sites in 40 countries, including those in the Americas, Europe, and Asia. Merck states that adverse events were equivalent between the odanacatib and placebo groups, including major adverse cardiovascular events. However, stroke events, skin lesions, and femoral fractures were more prevalent in the odanacatib group.
Due to Dr. Kaufman’s statement on the favorable benefit/risk profile for odanacatib, the company may view the safety results from the trial as a possible point of contention with regulatory agencies. Merck states that it is preparing additional support for its applications. The company plans to continue studying the participants as anticipated. It also intends to perform additional analyses of the data, including an independent review of cardiovascular events.