Effect of abaloparatide on fracture incidence and bone mineral density in postmenopausal women with osteoporosis at highest risk for fracture.

OBJECTIVE: This post hoc analysis evaluated the efficacy of abaloparatide treatment in a subgroup of postmenopausal women from the Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE; NCT01343004) study who met high fracture risk criteria (defined in several professional society guidelines).

METHODS: Women from ACTIVE meeting ≥1 of the following fracture risk criteria were included: fracture within the past 12 months or prevalent vertebral fracture, baseline T score of <-3.0 at any site, very high fracture risk probability by FRAX (ie, 10-yr major osteoporotic fracture >30% or hip fracture >4.5%), or multiple prior fractures at baseline since age ≥45 years.

RESULTS: A total of 2,026 participants met ≥1 fracture risk criteria defined in clinical guidelines (abaloparatide, n = 664; placebo, n = 677; teriparatide, n = 685). New vertebral fracture risk was reduced in participants receiving abaloparatide (4 [0.72%]) and teriparatide (6 [0.99%]) versus placebo (28 [4.77%]; both P  < 0.0001). Estimated Kaplan-Meier cumulative incidence of nonvertebral fracture was 3.0%, 5.3%, and 3.0% in the abaloparatide, placebo, and teriparatide groups, respectively; 4.0%, 9.0%, 4.3% for clinical fracture; 1.6%, 6.8%, 3.0% for major osteoporotic fractures; and 1.1%, 2.1%, 2.1% for wrist fracture. Abaloparatide was associated with bone mineral density gains from baseline at the lumbar spine, total hip, and femoral neck at all time points (6, 12, and 18 mo; P  < 0.0001 for all). Common adverse events reported in participants treated with abaloparatide were hypercalciuria (11.5%), dizziness (11.0%), and arthralgia (8.9%).

CONCLUSIONS: Abaloparatide reduced fracture incidence and increased bone mineral density in participants at highest fracture risk, consistent with the overall ACTIVE study.