RESUMO
ImportanceData on real-world effectiveness of subcutaneous (SC) administration of casirivimab and imdevimab (CAS+IMD) for treatment of COVID-19 are limited. ObjectiveTo assess effectiveness of SC CAS+IMD vs no COVID-19 antibody treatment among patients diagnosed with COVID-19 in ambulatory settings during the Delta-dominant period prior to Omicron emergence. DesignRetrospective cohort study. SettingEncrypted linked data between Komodo Health closed claims database and CDR Maguire Health & Medical database. ParticipantsPatients with COVID-19 in ambulatory settings between August 1, 2021 and October 30, 2021 treated with SC CAS+IMD were exact- and propensity score-matched to up to 5 untreated patients who were treatment-eligible under the Emergency Use Authorization (EUA) ExposureSubcutaneous CAS+IMD. Main Outcomes and MeasuresComposite endpoint of 30-day all-cause mortality or COVID- 19-related hospitalization. Kaplan-Meier estimators were used to calculate composite risk overall and across subgroups including age, COVID-19 vaccination status, immunocompromised, and elevated risk defined as age [≥] 65 years or 55-64 years with body mass index [≥] 35 kg/m2, type 2 diabetes, chronic obstructive pulmonary disease, or chronic kidney disease. Cox proportional- hazards models were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI). ResultsAmong 13 522 patients treated with SC CAS+IMD, 12 972 (95.9%) were matched to 41 848 EUA-eligible untreated patients; patients were 57-58% female, with mean age between 50 and 52 years. The 30-day composite outcome risk was 1.9% (95% CI, 1.7-2.2; 247 events) and 4.4% (95% CI, 4.2-4.6; 1822 events) in the CAS+IMD-treated and untreated cohorts, respectively; CAS+IMD treatment was associated with a 49% lower risk (aHR 0.51; 95% CI, 0.46-0.58). Treatment was also associated with a 67% lower 30-day risk of all-cause mortality (aHR 0.33, 95% CI, 0.18-0.60). Treatment effectiveness was consistent regardless of vaccination status and across subgroups, including those at elevated risk (aHR 0.51, 95% CI 0.42-0.60) or immunocompromised (aHR 0.34, 95% CI 0.17-0.66). Conclusions and RelevanceSubcutaneous treatment with CAS+IMD is effective for reducing all-cause mortality or COVID-19-related hospitalization in patients diagnosed with COVID-19 and managed in real-world outpatient settings during the Delta-dominant period. Effectiveness is maintained among immunocompromised, vaccinated, and elevated risk patients.
