Real-world Assessment of 2,879 COVID-19 Patients Treated with Monoclonal Antibody Therapy: A Propensity Score-Matched Cohort Study

Background SARS-CoV-2 continues to spread globally and cause significant morbidity and mortality. Anti-spike protein monoclonal antibody (mAb) therapy has been shown to prevent progression to severe COVID-19 disease. The objective of this study was to report the outcomes of high-risk, SARS-CoV-2-positive patients infused with one of the three mAb available through FDA emergency use authorization (EUA). Methods A total of 4,328 SARS-CoV-2-positive patients that satisfied EUA criteria for eligibility for receiving mAb therapy were infused with bamlanivimab or combination therapies bamlanivimab-etesevimab or casirivimab-imdevimab from November 22, 2020, to May 31, 2021, at six infusion clinics and multiple emergency departments within the eight Houston Methodist Hospitals in Houston, Texas. The primary outcome of hospital admission within 14- and 28-days post-infusion was assessed relative to a propensity-score matched cohort, matched based on age, race/ethnicity, median income by zip code, body mass index, comorbidities, and positive PCR date. Secondary outcomes included ICU admission and mortality. Results A total of 2,879 infused patients and matched controls were included in the analysis, including 1,718 patients infused with bamlanivimab, 346 patients infused with bamlanivimab-etesevimab, and 815 patients infused with casirivimab-imdevimab. Hospital admission and mortality rates were significantly decreased overall in mAb-infused patients relative to matched controls. Among the infused cohort, those who received casirivimab-imdevimab had significantly decreased rate of admission relative to the other two mAbs groups (aRR = 0.51, p=0.001). Conclusions Treatment with bamlanivimab, bamlanivimab-etesevimab, or casirivimab-imdevimab significantly decreased the number of patients who progressed to severe COVID-19 disease and required hospitalization.