Adherence to denosumab in the treatment of osteoporosis and its utilization in the Czech Republic

Objectives: The objective was to analyze adherence and current trends in utilization and prescription practice patterns of the anti-RANKL monoclonal antibody denosumab in the treatment of postmenopausal osteoporosis (OP). Methods: The prescription-based database of the General Health Insurance Company of the Czech Republic that covers approximately 60% of the Czech population (6 million) was used as the data source. Medication possession ratio (MPR) and persistence were calculated for all patients (both OP medication-naive and medication-experienced) with postmenopausal OP from the start of their therapy with denosumab 60 mg per ml subcutaneous injection within a period between September 2011, i.e. first denosumab availability, and May 2014. Clinical data such as fractures, co-morbidities and co-medication were not analyzed. Results: A total of 7904 women treated with denosumab were analyzed; 93.8% of patients were identified as compliant (MPR >= 0.8) while 6.2% were non-compliant (MPR<0.8). Persistence (base case, i.e. refill gap <= 30 days) was 59.1% after 12 months and 34.8% after 24 months. By 2013, i.e. within 2 years, denosumab became the second most utilized and most costly drug after oral bisphosphonates. Conclusions: Despite relatively high MPR and persistence rate observed in denosumab treatment, adherence enhancing strategies, focused on persistence in particular, are still needed. The uptake of denosumab has been rapid, its utilization keeps rising swiftly, and denosumab already represents a significant part of the osteoporosis therapy budget.