Abstract: T h e n e w e ng l a n d j o u r na l o f m e dic i n e Original Article Bamlanivimab plus Etesevimab in Mild or Moderate Covid-19 M. Dougan, A. Nirula, M. Azizad, B. Mocherla, R.L. Gottlieb, P. Chen, C. Hebert, R. Perry, J. Boscia, B. Heller, J. Morris, C. Crystal, A. Igbinadolor, G. Huhn, J. Cardona, I. Shawa, P. Kumar, A.C. Adams, J. Van Naarden, K.L. Custer, M. Durante, G. Oakley, A.E. Schade, T.R. Holzer, P.J. Ebert, R.E. Higgs, N.L. Kallewaard, J. Sabo, D.R. Patel, M.C. Dabora, P. Klekotka, L. Shen, and D.M. Skovronsky, for the BLAZE-1 Investigators*​​ A BS T R AC T BACKGROUND The authors’ full names, academic degrees, and affiliations are listed in the Appendix. Address reprint requests to Dr. Skovronsky at Eli Lilly, 893 Delaware St., Indianapolis, IN 46225, or at ­skovronsky _daniel@​­lilly​.­com. *A list of the BLAZE-1 investigators is provided in the Supplementary Appendix, available at NEJM.org. Drs. Dougan and Nirula contributed equally to this article. This article was published on July 14, 2021, at NEJM.org. N Engl J Med 2021;385:1382-92. DOI: 10.1056/NEJMoa2102685 Copyright © 2021 Massachusetts Medical Society. CME at NEJM.org Patients with underlying medical conditions are at increased risk for severe coronavirus disease 2019 (Covid-19). Whereas vaccine-derived immunity develops over time, neutralizing monoclonal-antibody treatment provides immediate, passive immunity and may limit disease progression and complications. METHODS In this phase 3 trial, we randomly assigned, in a 1:1 ratio, a cohort of ambulatory patients with mild or moderate Covid-19 who were at high risk for progression to severe disease to receive a single intravenous infusion of either a neutralizing monoclonal-antibody combination agent (2800 mg of bamlanivimab and 2800 mg of etesevimab, administered together) or placebo within 3 days after a laboratory diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The primary outcome was the overall clinical status of the patients, defined as Covid-19–related hospitalization or death from any cause by day 29. RESULTS A total of 1035 patients underwent randomization and received an infusion of bamlanivimab–etesevimab or placebo. The mean (±SD) age of the patients was 53.8±16.8 years, and 52.0% were adolescent girls or women. By day 29, a total of 11 of 518 patients (2.1%) in the bamlanivimab–etesevimab group had a Covid-19– related hospitalization or death from any cause, as compared with 36 of 517 patients (7.0%) in the placebo group (absolute risk difference, −4.8 percentage points; 95% confidence interval [CI], −7.4 to −2.3; relative risk difference, 70%; P<0.001). No deaths occurred in the bamlanivimab–etesevimab group; in the placebo group, 10 deaths occurred, 9 of which were designated by the trial investigators as Covid-19–related. At day 7, a greater reduction from baseline in the log viral load was observed among patients who received bamlanivimab plus etesevimab than among those who received placebo (difference from placebo in the change from baseline, −1.20; 95% CI, −1.46 to −0.94; P<0.001). CONCLUSIONS Among high-risk ambulatory patients, bamlanivimab plus etesevimab led to a lower incidence of Covid-19–related hospitalization and death than did placebo and accelerated the decline in the SARS-CoV-2 viral load. (Funded by Eli Lilly; BLAZE-1 ClinicalTrials.gov number, NCT04427501.) 1382 n engl j med 385;15 nejm.org October 7, 2021 The New England Journal..