Effect of Abaloparatide on Bone Mineral Density and Fracture Incidence in a Subset of Younger Postmenopausal Women with Osteoporosis at High Risk for Fracture
; however, by 60 years of age, half of all white women have osteopenia or osteoporosis.
Current guidelines recommend screening for postmenopausal women
or if they are at increased risk for fracture using a formal clinical-risk assessment tool.
In general, risk assessment includes a BMD T score of ≤−2.5 as the diagnostic threshold for osteoporosis and increased fracture risk; however, half of all fragility fractures occur in patients with a BMD in the osteopenia range (T score of −1 to −2.5), suggesting that BMD alone does not present a full picture of a woman’s risk for fracture.
A history of prior vertebral, hip, or multiple nonvertebral and nonhip fractures is an independent predictor of future fractures
but may be overlooked in patients with BMD >−2.5. Furthermore, although it has been suggested that trabecular bone score in combination with the fracture risk assessment tool (FRAX) is more sensitive than either method alone,
current risk assessment tools do not include measures of bone quality and microarchitecture, such as trabecular bone score, which could be contributing to fracture risk. Indeed, diagnosis and treatment of osteoporosis are low in women and men who sustained a fracture in both commercial and Medicare Advantage populations. Although these rates increased significantly after a fracture, they still remained below guideline-recommended levels.
Many women have a sentinel event before being diagnosed with osteoporosis and, consequently, are at increased risk for subsequent fracture.
In such patients, early access to anabolic therapy has the potential to decrease the risk of future fracture events, including downstream morbidity and mortality risks, as well as associated health care costs.
This study examined the safety and efficacy of the anabolic agent abaloparatide in a subgroup of women <65 years of age with a prior fracture and baseline T score of ≤−2.5 (any site) from the ACTIVE trial. Abaloparatide resulted in significant improvements in BMD compared with placebo in this subgroup. A nonsignificant, numerical risk reduction for vertebral and nonvertebral fractures was also seen, although these analyses were limited by the small number of fractures in this analysis. Efficacy and safety outcome results for this subgroup were generally consistent with the overall ACTIVE population.
for the full active population, for which the NNT was also less with abaloparatide versus teriparatide for nonvertebral and clinical fractures. In contrast with this analysis, Reginster et al
also found that the NNT was less with abaloparatide versus teriparatide for major osteoporotic fractures, whereas our study found a similar NNT between treatment groups.
As such, p values in this article should be interpreted with caution. In addition, because teriparatide was administered open label, reporting bias for subjective measures may have occurred.
Results from this subgroup analysis support the use of abaloparatide in a younger population of women who are at risk for fracture and whose coverage is through commercial insurance.