MON-790 - Romosozumab Following Anabolic Therapy in Severe Osteoporosis: A Case Series

Background:
Osteoporosis is characterized by the progressive loss of bone mass and deterioration of bone microarchitecture, resulting in increased bone fragility and fracture risk. Current guidelines generally support initiating treatment with an anabolic agent in patients with high fracture risk, followed by antiresorptive therapy for long-term maintenance. However, data examining the use of romosozumab following prior anabolic therapy remain limited.


Methods:
We describe three postmenopausal women with severe osteoporosis who completed treatment with an anabolic agent (18-24 months of abaloparatide or teriparatide) followed by 12 months of romosozumab. Changes in BMD were assessed using a DXA scan before and after completion of romosozumab therapy. Secondary causes of osteoporosis were excluded in all patients.

Cases Summary:
The series included three postmenopausal women. The first patient was a 77-year-old woman with severe osteoporosis and prior bisphosphonate intolerance who completed 24 months of teriparatide. The second patient was a 76-year-old woman with a history of a fragility wrist fracture who also completed 24 months of teriparatide. The third patient was a 66-year-old woman with severe osteoporosis who completed 18 months of abaloparatide. All patients had normal renal function and adequate vitamin D levels at the time of romosozumab initiation.


Results:
Across all three patients, treatment with romosozumab following prior anabolic therapy resulted in clinically significant improvements in BMD. Lumbar spine BMD increased by 6.5% to 16%, while femoral neck and total hip BMD showed gains ranging from stability to improvements of up to 11%. No new fragility fractures were reported during the romosozumab treatment period.


Discussion:
This case series demonstrates that sequential treatment with an anabolic agent followed by romosozumab is associated with continued and clinically significant improvements in BMD in postmenopausal women with severe osteoporosis and high fracture risk. The greatest gains were observed at the lumbar spine, with variable but favorable effects at the hip and femoral neck. Real-world studies, primarily from Japanese cohorts, have shown further increases in BMD when patients transition from teriparatide to romosozumab, with this sequence appearing more effective than the reverse.


Conclusion:
Sequential therapy with an anabolic agent followed by romosozumab was associated with continued BMD gains in postmenopausal women with severe osteoporosis and high fracture risk. These findings support the potential role of this approach in patients with persistent skeletal fragility after anabolic therapy. Larger prospective studies are needed to further define the role of this sequential strategy across diverse patient populations.

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