Effects of abaloparatide on bone mineral density and risk of fracture in postmenopausal women aged 80 years or older with osteoporosis

Abstract

Objective: Advanced age is an important risk factor for fracture. The Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE) trial showed that subcutaneous abaloparatide increased bone mineral density (BMD) and reduced the risk of vertebral and nonvertebral fractures in postmenopausal women with osteoporosis. This study describes the effects of abaloparatide in the subgroup of women aged 80 or more years in ACTIVE.

Methods: Post hoc analyses of BMD and fracture incidence in this subgroup of women who received abaloparatide or placebo in the 18-month, phase 3, double-blind, randomized controlled ACTIVE trial.

Results: The mean ages of the women ≥80 years were 81.9 and 81.7 years in the placebo (n = 43) and abaloparatide (n = 51) groups, respectively. The increases in BMD from baseline to 18 months with abaloparatide treatment were 3.9% at the total hip (P < 0.001), 3.6% at the femoral neck (P < 0.01), and 12.1% at the lumbar spine (P < 0.001), and were similar to those observed in the overall population. Abaloparatide therapy was associated with numerical, but not statistically significant, reductions in the risk of vertebral and nonvertebral fractures in this subpopulation, compared with placebo. The proportion of participants reporting adverse events was similar between treatment groups and between the older subgroup and the overall population.

Conclusion: Abaloparatide was effective in increasing BMD in the very elderly subgroup of ACTIVE, with a safety profile similar to that of the overall study population.

Figures

Figure 1

Mean percent change (95% confidence interval) in BMD at total hip, femoral neck, and lumbar spine among patients aged ≥80 years. *P

Figure 2

Fracture risk reduction after 18 months of treatment among (A) the overall population and (B) patients aged ≥80 years. Percentages for new vertebral fractures were calculated using the modified intent-to-treat population. Percentages of nonvertebral fractures were Kaplan-Meier estimates using the intent-to-treat populations. ABL-SC, abaloparatide-SC; CI, confidence interval; HR, hazard ratio; NS, not significant; RR, relative risk.