Osteoporotic, Postmenopausal Women: Abaloparatide Reduces Risk for New Fractures

Findings from a study recently published in JAMA suggest that in postmenopausal women with osteoporosis, the use of subcutaneous abaloparatide, compared with placebo, reduced the risk of new vertebral and nonvertebral fractures over 18 months (2016;316[7]:722-733.). 

Researchers Claus Christiansen, MD, (Helen Hayes Hospital, West Haverstraw, NY) and colleagues conducted a phase 3, double-blind, randomized clinical trial at 28 sites in 10 countries—the Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE) trial.

Postmenopausal women older than 65 with bone mineral density (BMD) T score ≤ -2.5 and > -5.0 at the lumbar spine or femoral neck, and radiological evidence ≥ 2 mild or ≥ 1 moderate lumbar or thoracic vertebral fracture or history of low-trauma, nonvertebral fracture within the past five years were eligible. Those with a T score ≤ -2.0 and > -5.0, or without fracture criteria and a T score ≤ -3.0 and > -5.0, could enroll.

Out of 2463 women (mean age, 69 years), 1901 completed the study. New morphometric vertebral fractures occurred in 0.58% (n = 4) of the abaloparatide group, 4.22% (n = 30) of the placebo group (risk difference [RD] vs placebo, -3.64 [95% CI, -5.42 to -2.10]; relative risk, 0.14 [95% CI, 0.05-0.39]; P < .001), and 0.84% (n = 6) of the teriparatide group. The Kaplan-Meier estimated event rate for nonvertebral fracture was 2.7% for abaloparatide, 4.7% for placebo; hazard ratio, 0.57 (95% CI, 0.32-1.00; P = .049), and 3.3% for teriparatide.

BMD increases were greater with abaloparatide than with placebo (all P < .001). Incidence of hypercalcemia was lower with abaloparatide (3.4%) than with teriparatide (6.4%) with an RD of -2.96 (95% CI, -5.12 to −0.87; P = .006).

Dr Christiansen and colleagues concluded that the risk of new vertebral and nonvertebral fractures in osteoporotic, postmenopausal women was reduced with the use of subcutaneous abaloparatide, but said that more research is needed in order to understand the risks and benefits of the treatment and its efficacy vs other osteoporosis treatments. —Amanda Del Signore