Endocrine Abstracts

Coronavirus disease 2019 (COVID-19), is a primarily respiratory infection which can lead to severe syndrome needing hospitalization and assisted ventilation with high lethality. In a recent meta-analysis of 33 RCTs increased risk of severe infections on treatment with Denosumab, widely used for treatment of osteoporosis, was found specifically for ear, nose, and throat. In fact, by inhibiting the receptor activator of nuclear factor κ-Β ligand, denosumab acts as an immune system modulator. However, despite these findings calling for caution, several recently published opinions recommended maintaining treatment with denosumab during the COVID-19 outbreak, We report on the incidence of symptomatic respiratory infections in denosumab vs other available drug treated osteoporotic population attending our bone clinic in Milano one of the centers of COVID-19 pandemic in Italy. We conducted a telephone interview on a sample of 85 patients (aged ≥18 years) regularly followed in our bone center for post-menopausal osteoporosis (n = 75) or under aromatase inhibitors (AI) for breast cancer (n = 10). We excluded patients with comorbidities and concomitant therapies potentially influencing COVID-19 morbidity such as chronic kidney disease and glucocorticoid treatment. All patients were asked the following questions concerning the 3 month period from February 21 to May 24.2020: 1. clinical symptoms of upper airway infection or diagnosis of pneumonia, 2. COVID-19 positive testing, hospitalization and related clinical course; 3. Falls. A total of 50 patients responded to the survey. Fifteen were treated with oral bisphosphonates (BP; mean age 68.8 ± 11.4), 29 with denosumab (D; mean age 79.2 ± 8.6) and 6 with teriparatide (T; mean age 75.0 ± 10.4). Median duration of treatment was 7, 26 and 10 months respectively. In the BP and D group: one patient reported self-limited fever and cough, none of the patients was hospitalized and two and one patient respectively reported one episode of fall without clinical consequences; in T group no patients reported symptoms of infection, hospitalization or falls. Our preliminary data suggest that denosumab may not represent specific risk factor for COVID-19. Our data give some initial real life evidence support to opinions which recommended to continue denosumab during COVID-19 pandemic. Interestingly, it can be hypothesized that female sex may have exerted a relevant protective effect. Finally, it can not be excluded a selection bias in the choice of our patients for denosumab treatment excluding a priori those with recurrent or at increased risk for respiratory infections.