Bone Abstracts

Background: Romosozumab is currently approved for the treatment of severe osteoporosis in postmenopausal women at very high risk of fracture. Evidence for its use in men with osteoporosis remains limited. We evaluated real-world bone mineral density (BMD) changes in a small male cohort who had received treatment through a specialist clinic.

Methods: A retrospective review of the medical notes of male patients who had received Romosozumab.

Results: Data was available on 7 men, mean age 49.6 years (range 32-69). Patients had idiopathic low bone mass at the lumbar spine (mean bone mass 0.728 g/cm², mean T-score -3.3) and to a lesser extent at the total hip (mean bone mass 0.777 g/cm2, mean T-score -1.7). One patient had a history of paroxysmal atrial fibrillation that was well controlled medically. There were no other patients with a cardiac history and their QRISK3 scores were low. Four patients completed 12 months of therapy. One patient remains on treatment and has yet to complete the full course of treatment. In two patients, treatment was discontinued at 6 months as they had achieved an adequate response and further treatment was not felt necessary. All patients who completed treatment, switched to an anti-resorptive with Alendronate being the most common. In those receiving 12 months of treatment, lumbar spine BMD increased by a mean of 20.8% (SD ±10.4%), while hip BMD increased by 2.3% (SD ±6.4%). In the two patients treated for only 6-months, lumbar spine BMD increased by a mean of 18.5%, while hip BMD changes were variable. Treatment was well tolerated and no patients experienced serious side effects. One patient had an injection-site reaction after initial dosing which settled with subsequent injections. There were no new fragility fractures during the treatment period.

Conclusion: Romosozumab produced substantial increases in lumbar spine BMD in men, evident as early as 6 months and sustained at 12 months. Hip responses were smaller and more variable. These findings support the anabolic efficacy of Romosozumab in male osteoporosis. No serious adverse effects were also seen.