Therapy with transitions from one bone-forming agent to another: a retrospective cohort study on teriparatide and romosozumab.

This study aimed to evaluate the effectiveness of sequential therapy with a bone formation-promoting agent (either teriparatide or romosozumab) for osteoporosis treatment following prior treatment with the other bone-forming agent (teriparatide or romosozumab). This is a multicenter retrospective cohort study observing 2 groups for comparison: one with 69 patients transitioning from teriparatide to romosozumab (the T2R group) and the other with 25 patients transitioning from romosozumab to teriparatide (the R2T group), monitored for 12 months on the second drug. Key outcomes included changes in bone mineral density (BMD), bone turnover marker changes, and adverse events. The mean ages of each group were 72.3 years in the T2R group and 67.6 years in the R2T group, with the proportions of women being 91.3% and 80.0%, respectively. The percent changes of BMD in the lumbar spine after 12 months of sequential therapy were +10.8% in the T2R group ( < .001 versus baseline) and -0.0% in the R2T group ( = .875). The percent changes in BMD in the total hip and femoral neck were +4.4% and +4.4% in the T2R group, and -1.3% and -0.8% in the R2T group, respectively. When comparing the 2 groups, BMD changes at all sites in the T2R group were significantly higher than those in the R2T group ( < .001). Furthermore, when examining the changes in the proportion of patients who achieved the osteoporosis treatment goal of a T-score exceeding -2.5, no significant increase was observed in the R2T group, whereas a significant increase was observed in the lumbar spine in the T2R group. Regarding therapy switching between bone-forming agents, this study suggests that transitioning from teriparatide to romosozumab increases BMD more effectively than transitioning in the opposite sequence.