Abstract: medRxiv preprint doi: https://doi.org/10.1101/2022.04.03.22273360; this version posted April 5, 2022. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. 1 2 Real World Evidence of the Neutralizing Monoclonal Antibody Sotrovimab for Preventing Hospitalization and Mortality in COVID-19 Outpatients 3 4 5 6 Neil R. Aggarwal, MD, MHSca*; Laurel E. Beaty, MSb*; Tellen D. Bennett, MD, MS c,e; Nichole E. Carlson, PhD, MSb,e; Christopher B. Davis, MDd; Bethany M. Kwan, PhD, MSPHd,e,f; David A. Mayer, BSb; Toan C. Ong, PhDc; Seth Russell, MSc; Jeffrey Steele, RNg; Adane F. Wogu, PhDb; Matthew K. Wynia, MD, MPHa,h,i; Richard D. Zane, MDd; Adit A. Ginde, MD, MPHd,e 7 a 8 9 b Department of Medicine, University of Colorado School of Medicine, Aurora, 80045, USA Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, 80045, USA 10 11 c 12 13 d 14 15 e 16 17 f 18 g 19 20 h 21 22 i 23 * 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 See Supplement for a full list of Contributors. Section of Informatics and Data Science, Department of Pediatrics, University of Colorado School of Medicine, Aurora, 80045, USA Department of Emergency Medicine, University of Colorado School of Medicine, Aurora, 80045, USA Colorado Clinical and Translational Sciences Institute, University of Colorado Anschutz Medical Campus, Aurora, 80045, USA Department of Family Medicine, University of Colorado School of Medicine, Aurora, 80045, USA Research Informatics, Children’s Hospital Colorado, Aurora, 80045, USA Center for Bioethics and Humanities, University of Colorado, Anschutz Medical Campus, Aurora, 80045, USA Department of Health Systems Management and Policy, Colorado School of Public Health, Aurora, 80045, USA Contributed equally to this manuscript Corresponding author: Neil R. Aggarwal, MD, MHSc Department of Medicine University of Colorado School of Medicine 12700 E. 19th Ave, Mail Stop C-272 Aurora, CO 80045, USA Phone: +1-303-724-6038 Email: neil.aggarwal@cuanschutz.edu Running title: Sotrovimab for COVID-19 Outpatients Word counts: Abstract: 199, Manuscript text: 2944 NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice. 1 medRxiv preprint doi: https://doi.org/10.1101/2022.04.03.22273360; this version posted April 5, 2022. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. 39 ABSTRACT 40 Background: It is not known whether sotrovimab, a neutralizing monoclonal antibody (mAb) 41 treatment authorized for early symptomatic COVID-19 patients, is effective against the SARS- 42 CoV-2 Delta variant to prevent progression to severe disease and mortality. 43 Methods: Observational cohort study of non-hospitalized adult patients with SARS-CoV-2 44 infection from October 1st 2021 - December 11th 2021, using electronic health records from a 45 statewide health system plus state-level vaccine and mortality data. We used propensity 46 matching to select 3 patients not receiving mAbs for each patient who received outpatient 47 sotrovimab treatment. The primary..