Progression of multiple vertebral fractures after Denosumab discontinuation under treatment with Romosozumab. A case-report.

INTRODUCTION: Denosumab (Dmab) is widely used for the treatment of post-menopausal osteoporosis. Its discontinuation is sometimes accompanied by multiple vertebral fractures. Romosozumab (Rmab) has not been tested for its ability to prevent the rebound phenomenon.

CASE PRESENTATION: We present the case of a 68-year-old female patient with post-menopausal osteoporosis under treatment with Rmab who presented with multiple vertebral fractures after denosumab discontinuation. The addition of Rmab did not prevent new-onset rebound-associated vertebral fractures. The patient discontinued Rmab and Dmab was re-initiated. After six months, no new vertebral fractures occurred, bone mineral density increased and bone turnover markers remained suppressed.

DISCUSSION: Our clinical case illustrates the effectiveness of Rmab to prevent the multiple vertebral fracture cascade attributable to discontinuation of Dmab. We believe that treatment with Rmab might not be enough to prevent this phenomenon. Treatment with Dmab or possibly combination treatment with Dmab and Rmab could be another treatment option.