Use of raloxifene as a sequential therapy after romosozumab : an observational study.

Objective: There have been no studies on the effectiveness of raloxifene as an antiresorptive agentfollowing discontinuation of romosozumab. The aim of this study was to investigate the potential effectiveness of raloxifene following a romosozumab therapy.

Methods: This study had an observational pre-post design and included 23 patients. Romosozumab 210 mg was administered subcutaneously once every 4 weeks for 12 months, after which all patients received raloxifene 60 mg/day for 24 months. We investigated the incidence of new fractures, safety, and bone mineral density (BMD).

Results: We found no new fractures or adverse events. After the treatment with romosozumab, percent changes from baseline in BMD at the spine and total hip in treatment-naïve patients with primary osteoporosis (the Naïve-P group) were 12.3% and 4.6%, respectively. After subsequent administration of raloxifene, spinal and total hip BMD in the Naïve-P group decreased to baseline levels at 36 months and 30 months, respectively. Six months after switching to raloxifene, the respective percent changes from baseline in spinal and total hip BMD were 12.0% and 5.8%.

Conclusion: Romosozumab followed by raloxifene is acceptable for use for only 6 months in the Naïve-P group. However, more aggressive use of this agent is not recommended. J. Med. Invest. 72 : 124-133, February, 2025.