Adherence to denosumab during the COVID-19 pandemic

Abstract

Introduction: we aimed to analyze whether the SARS-CoV-2 pandemic has led to a decrease in denosumab (Dmab) adherence in the population, and assess the incidence of subsequent fractures in non-adherent patients. Methods: we assessed all patients who should have required the administration of a dose of Dmab in Cantabria (Spain), during the lockdown Sociodemographic variables, risk factors for osteoporosis, data on Dmab administration, and the reason for drug discontinuation were collected. Furthermore, the development of a subsequent clinical fracture during the following year was also analyzed. Results: a total of 2948 patients should have received a new dose of Dmab during the lockdown months, but 546 (18.5 %) discontinued the drug. The main reason for withdrawal was the patient's own doing (65 %). The incidence of clinical fractures in the overall group was low (n = 45; 1.46 %) with only 4 vertebral and 3 hip fractures being reported. When the group that did not receive more doses of Dmab or an alternate antiosteoporotic agent was analyzed (n = 147), it was revealed that 2 patients (1.36 %) sustained a vertebral fracture and another one (0.68 %) a hip fracture during the year following the last dose of the drug. Conclusions: there was a non-negligible percentage of patients who did not receive the dose of Dmab on time during the lockdown period. However, the incidence of clinical vertebral and non-vertebral fractures was low, even in the non-compliant subjects who did not receive a different antiosteoporotic agent. None of the patients sustained multiple vertebral fractures at the 1-year follow-up.