Probability of Achieving Bone Mineral Density Treatment Goals with Denosumab Treatment in Postmenopausal Women with Osteoporosis.

Abstract

Bone mineral density (BMD) levels achieved on osteoporosis treatment are predictive of subsequent fracture risk, and T-score > -2.5 has been proposed as a minimum treatment target for women with osteoporosis. Knowing the likelihood of attaining target T-scores with different medications for different baseline BMD levels can help determine appropriate initial treatment for individual patients. In this post hoc analysis, we estimated the probability of achieving a non-osteoporotic T-score (> -2.5 or ≥ -2.0) at the total hip (TH) or lumbar spine (LS) in postmenopausal women >60 years old treated with denosumab for either 3 or 10 years in the FREEDOM trial and its long-term extension. In women with baseline TH T-scores of -2.7, -3.0, and -3.5, the probabilities of achieving target T-scores > -2.5 with 3 years of denosumab were 71%, 12%, and 0.1%, respectively. At LS, for baseline T-scores of -2.7, -3.0, and -3.5, the probabilities were 86%, 59%, and 11%, respectively. Longer treatment duration of up to 10 years increased the probability of achieving target T-scores. The baseline T-scores that permitted at least 50% of women to achieve a target T-score > -2.5 was -2.8 at TH and -3.1 at LS after 3 years and -3.0 at TH and -3.7 at LS after 10 years of treatment. To achieve higher treatment targets (T-scores ≥ -2.0), overall probabilities were lower at both skeletal sites, particularly for TH, even with longer treatment duration. Our results demonstrate that the probability of achieving T-score targets with denosumab is dependent on baseline BMD, skeletal site, and treatment duration. Knowing the probability of achieving treatment targets for different baseline TH and LS T-scores can help determine whether denosumab is an appropriate first choice of treatment in individual patients.