Predictive Factors for Achievement of Treatment Goals in Patients with Postmenopausal Osteoporosis Treated with Denosumab

Objectives To investigate efficacy of long-term treatment with denosumab and predictive factors for achievement of treatment goals in patients with postmenopausal osteoporosis (PMO). Methods We enrolled 111 PMO patients who had T-scores ≤ -2.5 either at the lumbar spine (L-) or femoral neck (FN-), who had never been treated for osteoporosis, and who could be followed for at least 3 years. We first evaluated changes in bone mineral density (BMD) for up to 7 years. We next defined the treatment goal as the achievement of a T-score > -2.5 at month 36 and performed multivariate analysis to identify predictive factors for achievement of the goal. Results L- and FN-BMD increased yearly for 7 years. Among 87 patients with baseline L-T-scores ≤ -2.5, better baseline L-T-scores predicted achievement of L-T-scores > -2.5 at month 36. The cut-off value for baseline L-T-score was -3.4. Among 76 patients with baseline FN-T-scores ≤ -2.5, better baseline FN-T-scores predicted achievement of FN-T-scores > -2.5 at month 36. The cut-off value for baseline FN-T-scores was -2.8. Conclusions Long-term treatment with denosumab was effective in PMO patients. As better baseline T-score predicted achievement of T-scores > -2.5, early initiation of treatment will contribute to better outcome.