Bone mineral density at the femoral neck and total hip is a potential surrogate for fracture risk in clinical trials of osteoporosis drugs, according to findings presented at the American Society for Bone and Mineral Research Annual Meeting.
Using pooled data from 21 randomized, placebo-controlled osteoporosis drug trials, Dennis Black, PhD, professor and division head of clinical trials and multicenter studies in the department of epidemiology and biostatistics at the University of California, San Francisco, and colleagues estimated percent of treatment explained by change in BMD over 2 years. The trials included 83,395 participants with DXA data in clinical investigations of bisphosphonates, selective estrogen receptor modulators, estrogen, odanacatib (Merck), denosumab (Prolia, Amgen), parathyroid hormone (PTH) 1-34 (Forteo, Eli Lilly) and PTH 1-84 (Natpara, NPS Pharmaceuticals). Percent of treatment explained was calculated from BMD trajectories over 24 months (estimated with linear mixed models) and the effect of the treatment on time to vertebral, nonvertebral and hip fracture (estimated with nested pooled regression models).
Among the pooled cohort, there were 4,515 vertebral, 6,608 nonvertebral and 873 hip fractures. Researchers found that change in femoral BMD over 24 months accounted for 65% (95% CI, 53-77) of treatment effect for vertebral fractures, 74% (95% CI, 43-105) for nonvertebral fractures and 65% (95% CI, 24-106) for hip fractures, with similar results for change in total hip BMD.
“Our results indicate that changes in total hip and femoral neck BMD explain a large proportion of the treatment-related reduction in fracture risk for all three fracture types,” the researchers wrote in the abstract. “Importantly, this analysis included therapies with differing mechanisms of action. These data, along with others generated from this project, support the potential value of DXA BMD change as a surrogate for fractures in future trials.” – by Phil Neuffer
Black D, et al. Abstract FRI-1070. Presented at: American Society for Bone and Mineral Research Annual Meeting; Sept. 28-Oct. 1, 2018; Montreal.
Disclosure: Black reports he is a consultant for Asahi-Kasei and Radius and a speaker for Roche Diagnostics.