Promising potential for osteoporosis
Phase 2 study of Radius Health's abaloparatide increases bone density in postmenopausal women
WALTHAM, Mass.—As women age, their risk of developing osteoporosis increases. Radius Health Inc., a biopharmaceutical company advancing treatments for osteoporosis, recently published Phase 2 results of an investigational drug that could offer a new option for women facing bone loss.
The Phase 2 trial was a multi-center, multi-national, double-blind placebo-controlled study evaluating abaloparatide's effects on bone mineral density, with the results appearing online for early release on Nov. 13 from the Journal of Clinical Endocrinology & Metabolism. Radius Health's abaloparatide is a synthetic peptide analog of parathyroid hormone-related protein (PTHrP) currently in development as an anabolic agent for the treatment of postmenopausal osteoporosis.
As noted in a December 2013 article in Current Osteoporosis Reports, anabolic agents “reverse the negative skeletal balance that characterizes osteoporosis by stimulating osteoblast-dependent bone formation to a greater degree than osteoclast-dependent bone resorption. Parathyroid hormone (PTH) and parathyroid hormone- related protein (PTHrP) are peptide hormones, which have anabolic actions when administered intermittently.” The article, “Parathyroid Hormone and Parathyroid Hormone-Related Protein Analogs as Therapies for Osteoporosis,” was authored by Drs. Marilyn Augustine and Mara J. Horwitz of the Division of Endocrinology at the University of Pittsburgh School of Medicine.
The study focused on the effects of three different doses of abaloparatide on bone mineral density at the lumbar spine, total hip and femoral neck in 222 postmenopausal women with osteoporosis against placebo and teriparatide, an active known as Forteo marketed by Eli Lilly and Co. for the treatment of osteoporosis in men and postmenopausal women. The primary outcome measures were bone mineral density by dual x-ray absorptiometry and biochemical markers of bone turnover.
Patients received daily subcutaneous injections of placebo, 20-mug of teriparatide or 20, 40 or 80-mug of abaloparatide. A 24-week extension was also conducted in a small population of subjects. Twenty-four weeks of abaloparatide administration was shown to increase bone mineral density in a dose-dependent manner and to a greater extent than placebo at all three examination sites. The results seen in the limited population that was enrolled in the extension study suggest that the bone density increases due to abaloparatide stay fairly linear during the first year of treatment.
"The encouraging results being published in the current issue of JCEM support the continued development of abaloparatide as an anabolic therapy for potential use in the treatment of postmenopausal osteoporosis. We look forward to announcing the top-line 18-month fracture data from our Phase 3 ACTIVE study in late December 2014," Robert Ward, president and CEO of Radius Health, commented in a press release.
Radius Health also recently saw the completion of its Phase 3 ACTIVE clinical trial, which is investigating abaloparatide-SC for use in reducing fractures in postmenopausal osteoporosis.
Some 10 million Americans are faced with osteoporosis, and about 8 million, or 80 percent of those, are women, according to the National Osteoporosis Foundation. Women tend to be at a greater risk for osteoporosis due to their tendency toward smaller, thinner bones, and due to menopause; estrogen protects bones, but the body's production of this hormone decreases sharply at the onset of menopause, which can lead to bone loss. The National Osteoporosis Foundation reports that roughly two million broken bones are attributed to this disease each year, resulting in $19 billion in related costs annually. It's forecast that by 2025, osteoporosis will be the cause of approximately three million bone fractures and $25.3 billion in annual related costs.
