Romosozumab Followed by Antiresorptive Treatment Increases the Probability of Achieving Bone Mineral Density Treatment Goals

Increases in bone mineral density (BMD) with osteoporosis treatment are associated with reduced fracture risk. Increasing BMD is therefore a goal of osteoporosis therapy. Here, we compare the probability of achieving a T-score of > −2.5 over 3 years at the total hip (TH) or lumbar spine (LS) in women with osteoporosis, ≥55 years of age, after the following treatment sequences: 1 year romosozumab followed by 2 years denosumab (FRAME and FRAME extension trials), 1 year romosozumab followed by 2 years alendronate, or alendronate-only for 3 years (ARCH trial). Probabilities of attaining the BMD target within 1 year of treatment were also determined. At both skeletal sites, in women with a baseline Tscore ≥ −2.7, there was >50% probability of achieving the BMD target with any 3-year regimen. The probability of achieving the target BMD in those with a baseline TH Tscore equal to −3.0 was 61% with romosozumab/denosumab, 38% with romosozumab/alendronate, and 9% with alendronate. In those with a baseline LS Tscore equal to −3.0, the probability of achieving a T-score > −2.5 was 93% with romosozumab/denosumab, 81% with romosozumab/alendronate, and 55% with alendronate. With 1 year of treatment, in patients with a baseline TH T-score equal to −2.7, the probability of reaching the target Tscore with romosozumab was 71% to 78% and 38% with alendronate. For patients with an initial LS T-score equal to −3.0, the probability of achieving the target T-score over 1 year was 85% to 86% with romosozumab and 25% for alendronate. Our findings suggest baseline BMD and the probability of achieving BMD T-score goals are factors to consider when selecting initial treatment for patients with osteoporosis. As baseline T-score falls below −2.7 (TH) and −3.0 (LS), alendronate has <50% likelihood of achieving a BMD goal above osteoporosis range, whereas these probabilities remain relatively high for regimens beginning with romosozumab.