Denosumab Therapy Beyond 10 Years: Subsequent Treatment and Densitometric Outcomes.

OBJECTIVE

We described treatment approaches after 20 doses of denosumab, including continuation or transition to zoledronic acid or romosozumab, and examined subsequent BMD trajectories.

METHODS

This retrospective single-centre cohort included patients who received ≥20 consecutive doses of denosumab at the Osteoporosis Centre between June 2012 and December 2024. Characteristics of patients who continued denosumab were compared with those who transitioned to zoledronic acid or romosozumab. BMD was obtained from DXA, and trajectory analyses were restricted to patients without delayed dosing and with BMD reassessment after the 20th dose.

RESULTS

Fifty-four patients received ≥20 doses (mean age 72.9 years, 98.1% female). The 20th-dose BMD T-score was the major determinant of subsequent treatment: 2 patients with the lowest T-scores transitioned to romosozumab, 4 with the highest transitioned to zoledronic acid, and 48 continued denosumab. Continuing denosumab led to further BMD gains at the lumbar spine and femoral neck but not the total hip. Transition to zoledronic acid led to partial loss of the year-10 BMD gains. Transition to romosozumab led to further BMD gain at the lumbar spine only. No cases of atypical femoral fracture or osteonecrosis of the jaw were reported.

CONCLUSION

After ≥20 doses of denosumab, most patients continued treatment, guided largely by the 20th-dose BMD T-score. Continuing denosumab beyond 10 years resulted in further increases in BMD at the lumbar spine and maintenance of BMD at the femoral neck, whereas transition to zoledronic acid led to partial loss of previous gains and transition to romosozumab increased lumbar spine BMD only.