Abaloparatide Associated With Lower Risk of Fractures in Postmenopausal Women With Osteoporosis, High BMI

Among postmenopausal women with osteoporosis and high body mass index (BMI), abaloparatide was found to lead to significant risk reduction in new vertebral, nonvertebral, and major osteoporotic fractures, as well as significant improvement in bone mineral density (BMD), according to research presented at the 30th Annual Scientific and Clinical Congress of the American Association of Clinical Endocrinologists (ENVISION 2021).

The findings are based on a post hoc analysis of the phase 3 ACTIVE trial (ClinicalTrials.gov Identifier: NCT01343004) that assessed the efficacy and safety of abaloparatide, a selective activator of the PTH1 receptor signaling pathway, in postmenopausal women with osteoporosis. A total of 2463 women were randomly assigned 1:1:1 to double-blind daily abaloparatide 80 μg or placebo, or open-label teriparatide 20 μg administered subcutaneously for 18 months.

A subgroup of 823 patients with high BMI (≥27 kg/m²; ≥24 kg/m² for Asian women) were included in the post hoc analysis. Endpoints included BMD, new vertebral fractures, nonvertebral fractures, any clinical fractures, and major osteoporotic fractures.

In the abaloparatide group (n=262), mean (SD) age was 69.4 (6.1) years, and mean BMI was 28.9 (2.2) kg/m². In the placebo group (n=280), mean age was 68.8 (6.5) years, and mean BMI was 29.1 (2.1) kg/m². In the teriparatide group (n=281), mean age was 69.2 (6.7) years, and mean BMI was 29.1 (2.1) kg/m².

Abaloparatide and teriparatide were associated with a significant reduction in new vertebral fractures compared with placebo. The abaloparatide group had an absolute risk reduction of 3.8% and a relative risk reduction of 81%. The teriparatide group had an absolute risk reduction of 3.5% and a relative risk reduction of 74%.

The investigators also observed a significant reduction in nonvertebral and major osteoporotic fractures with abaloparatide compared with placebo (P <.05). Kaplan-Meier estimates showed event rates of 3.3 for clinical fractures in the abaloparatide group (vs 6.7 for placebo and 5.7 for teriparatide) and 0.9 for wrist fractures in the abaloparatide group compared with 3.4 in the placebo group vs 2.0 in the teriparatide group.

The study authors found significant increases in BMD at 6, 12, and 18 months compared with baseline in women who received abaloparatide vs placebo and teriparatide vs placebo at the total hip, femoral neck, and lumbar spine (P <.01). Significantly greater BMD increases were found with abaloparatide vs teriparatide at the total hip at all timepoints, at the femoral neck at 12 and 18 months, and at the lumbar spine at 6 months (P <.05).

Treatment-emergent adverse events were similar among the 3 groups and in the high-BMI group compared with the overall ACTIVE population. Serious treatment-emergent adverse events occurred in 13.7% of the abaloparatide group, 11.8% of the placebo group, and 13.9% of the teriparatide group. The most frequently occurring adverse events in the abaloparatide group were dizziness (11.1%), hypercalciuria (9.5%), hypertension (9.5%), and arthralgia (9.2%).

“Results from this post hoc analysis suggest abaloparatide may provide a valuable treatment option for women with postmenopausal [osteoporosis] and obesity at high risk for fracture,” the investigators commented.

Disclosures: The study was funded by Radius Health, Inc. The study authors declared affiliations with pharmaceutical companies. Please see the original reference for a full list of disclosures.

Reference

Garvey WT, Nikonova E, Wang Y, Schafer A. Effect of abaloparatide on bone mineral density and fracture incidence in postmenopausal women with osteoporosis and obesity. Presented at: 2021 AACE Virtual Annual Meeting, May 26-29, 2021.