Long-term persistence with denosumab: real-world data from the Austrian Osteoporosis Clinic (AOC). A retrospective data analysis

In short-term studies, persistence with denosumab has been higher than with other osteoporosis drugs. This study shows that persistence can be maintained in the long-term and is associated with efficacy and safety parameters. Purpose To assess long-term persistence with denosumab in postmenopausal women with osteoporosis. Secondary purposes were the evaluation of changes in efficacy and tolerance/safety parameters over time. Methods Persistence was determined by number and rate of patients receiving denosumab on time in 6-month intervals (+ / - 8 weeks). The total population was stratified by internal patients (injections and monitoring at the Austrian Osteoporosis Clinic [AOC], 74%) and external patients (injections at the practitioner's office with occasional monitoring at the AOC, 26%). In internal patients, efficacy parameters including bone mineral density (BMD) and the bone marker CTX were assessed at fixed time points and tolerance/safety parameters including side effects (SEs), adverse events (AEs), and serious AEs (SAEs) evaluated. Results Of 851 patients, 71% (73% internal and 64% external) were persistent at 7.5 years of follow-up. The mean rate of cumulative persistence in internal patients decreased from 94% at the time of the second dose to 73% at the time of the fifteenth dose. BMD increased and CTX decreased, overall and in pairwise comparisons (all p < .001). AEs and SAEs, but not SEs, were lower in persistent than non-persistent patients. Conclusions This is the first study showing that long-term (> 3 years) real-world persistence with denosumab could be maintained at a high level (> 70%) in most patients. Denosumab was well tolerated and associated with decreased CTX levels and increased BMD.