Change in effectiveness of sotrovimab for preventing hospitalization and mortality for at-risk COVID-19 outpatients during an Omicron BA.1 and BA.1.1-predominant phase

Objectives: Sotrovimab effectively prevented progression to severe disease and mortality following in-fection with pre-Omicron SARS-CoV-2 variants. We sought to determine whether sotrovimab is similarly effective against SARS-CoV-2 Omicron variant infection. Methods: Observational cohort study of non-hospitalized adult patients with SARS-CoV-2 infection from December 26, 2021, to March 10, 2022, using electronic health records from a statewide health system. We propensity-matched patients not receiving authorized treatment for each patient treated with sotro-vimab. The primary outcome was 28-day hospitalization; secondary outcomes included mortality. We also propensity-matched sotrovimab-treated patients from the Omicron and Delta phases. Logistic re-gression was used to determine sotrovimab effectiveness during Omicron and between variant phases.Results: Of 30,247 SARS-CoV-2 Omicron variant infected outpatients, we matched 1542 receiving sotro-vimab to 3663 not receiving treatment. Sotrovimab treatment was not associated with reduced odds of 28-day hospitalization (2.5% vs 3.2%; adjusted odds ratio [OR] 0.82, 95% CI 0.55, 1.19) or mortality (0.1% vs 0.2%; adjusted OR 0.62, 95% CI 0.07, 2.78). Between phases, the observed treatment OR was higher during Omicron than during Delta (OR 0.85 vs 0.39, respectively; interaction P-value = 0.053).Conclusion: Real-world evidence demonstrated that sotrovimab was not associated with reduced 28-day hospitalization or mortality among COVID-19 outpatients during the Omicron BA.1 phase.(c) 2022 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )