Fewer postmenopausal fractures

WALTHAM, Mass.—Radius Health, Inc. announced positive top-line data from the first six months of the ACTIVExtend trial that showed women who were previously treated with 18 months of abaloparatide (ABL) subcutaneous (SC) injection experienced no new vertebral fractures and an increased bone mineral density (BMD) during the first six months of treatment on alendronate (ALN). These data were presented October 12 at a plenary oral session during the American Society for Bone and Mineral Research (ASBMR) 2015 Annual Meeting.

The first six months of the Phase 3 ACTIVExtend trial were conducted in 1,139 subjects enrolled in the ACTIVE trial, who completed 18 months of treatment with either ABL-SC or placebo. Patients in the ACTIVE study were offered up to 24 additional months of treatment with ALN at a dose of 70 mg per week.

“There is a significant need for additional treatment options for women with postmenopausal osteoporosis who are at risk of experiencing a fracture,” said Dr. Felicia Cosman, lead investigator of the ACTIVExtend trial, osteoporosis specialist and medical director of the Clinical Research Center at Helen Hayes Hospital, senior clinical director of the National Osteoporosis Foundation and professor of medicine at Columbia University. “Abaloparatide was designed to have a unique mechanism of action with the goal of stimulating bone formation, increasing bone mineral density, restoring bone microarchitecture and augmenting bone strength. Impressive results on bone density and fracture risk were seen throughout the skeleton after the first six months of the ACTIVExtend trial, when women were given alendronate after 18 months of abaloparatide treatment. This therapeutic sequence could have the potential to help a broad range of osteoporosis patients.”

Over a 25-month period, women in the ABL-SC/ALN treatment group on average achieved a 12.8 percent increase in BMD at the lumbar spine, a 5.5 percent increase in BMD at the total hip and a 4.5 percent increase in BMD at the femoral neck. In this treatment group, 20.4 percent of patients achieved a 6 percent increase or greater in BMD at all three sites (lumbar spine, total hip and femoral neck).

The adverse events reported during the ALN treatment period were consistent with previous clinical experience. The most common adverse events included arthralgia, dyspepsia, upper respiratory infection, urinary tract infection and bone pain.

"These data build on the positive top-line results from the previously presented ACTIVE trial, which supports the potential use of abaloparatide in women with postmenopausal osteoporosis," said Robert E. Ward, president and CEO at Radius Health. "Osteoporosis is often undiagnosed and is a major public health concern worldwide. We are focusing on providing patients with options for managing this undertreated disease, and we look forward to advancing our U.S. and European regulatory submissions for abaloparatide.”

ACTIVExtend is an extension study evaluating 24 months of standard-of-care osteoporosis management in women who were at risk for experiencing a fracture, following completion of 18 months of ABL-SC or placebo treatment in the Phase 3 ACTIVE trial.

Osteoporosis affects many postmenopausal women since the production of estrogen, a hormone in women that protects bones, decreases sharply when women reach menopause, resulting in bone loss and increasing the risk for a fracture. Approximately one in two women over age 50 will break a bone because of osteoporosis.

The World Health Organization has officially declared osteoporosis a public health crisis. Osteoporosis is a silent disease, often displaying no signs or symptoms until a broken bone occurs. When a woman experiences a fracture, it can often have devastating consequences and make it hard to complete daily activities, such as driving, climbing stairs or even walking.

These fractures are common and place an enormous medical and personal burden on postmenopausal women. Over 200 million people worldwide suffer from osteoporosis, and two million osteoporosis-related fractures occur annually in the United States.

The majority of osteoporosis patients remain undiagnosed and undertreated, and there is an unmet medical need for treatment of incident non-vertebral fractures which currently represent 73 percent of all fractures.

Radius Health’s investigational drug abaloparatide is a synthetic peptide analog of human parathyroid hormone-related protein (hPTHrP), a naturally occurring bone-building hormone that has the potential to increase bone mineral density by stimulating new bone formation. Abaloparatide-SC is currently completing Phase 3 development for potential use as a daily self-administered injection for the treatment of patients with postmenopausal osteoporosis, who are at an increased risk for a fracture. Radius is also developing the investigational drug abaloparatide-transdermal for potential use as a short wear-time transdermal patch designed to administer abaloparatide without the need for subcutaneous injection based on 3M's patented Microstructured Transdermal System technology.

Through cutting-edge science, Radius Health discovers, develops and plans to deliver innovative therapies for the large and underserved osteoporosis patient population, as well as other serious endocrine-mediated diseases including metastatic breast cancer. The company's lead investigational drug product candidate, abaloparatide, is in development, in both injection (Abaloparatide-SC) and transdermal (Abaloparatide-TD) methods of administration, for the potential prevention of fractures in postmenopausal women who are at risk of fracture from osteoporosis. The Radius clinical portfolio also includes an investigational drug, RAD1901, for the treatment of hormone-driven, or hormone-resistant, metastatic breast cancer and vasomotor symptoms.