Subcutaneous REGEN-COV Antibody Combination to Prevent Covid-19
Meagan P. O’Brien, Eduardo Forleo‐Neto, Bret J. Musser, Flonza Isa, Kuo‐Chen Chan, Neena Sarkar, Katharine J. Bar, Ruanne V. Barnabas, Dan H. Barouch, Myron S. Cohen, Christopher B. Hurt, Dale R. Burwen, Mary Marovich, Peijie Hou, Ingeborg Heirman, John D. Davis, K. C. Turner, Divya Ramesh, Adnan Mahmood, Andrea T. Hooper, Jennifer D. Hamilton, Yun‐Ji Kim, Lisa A. Purcell, Alina Baum, Christos A. Kyratsous, James Krainson, Richard Perez-Perez, Rizwana Mohseni, Bari Kowal, A. Thomas DiCioccio, Neil Stahl, Leah Lipsich, Ned Braunstein, Gary Herman, George D. Yancopoulos, David M. Weinreich
Abstract
BACKGROUND: REGEN-COV (previously known as REGN-COV2), a combination of the monoclonal antibodies casirivimab and imdevimab, has been shown to markedly reduce the risk of hospitalization or death among high-risk persons with coronavirus disease 2019 (Covid-19). Whether subcutaneous REGEN-COV prevents severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and subsequent Covid-19 in persons at high risk for infection because of household exposure to a person with SARS-CoV-2 infection is unknown. METHODS: We randomly assigned, in a 1:1 ratio, participants (≥12 years of age) who were enrolled within 96 hours after a household contact received a diagnosis of SARS-CoV-2 infection to receive a total dose of 1200 mg of REGEN-COV or matching placebo administered by means of subcutaneous injection. At the time of randomization, participants were stratified according to the results of the local diagnostic assay for SARS-CoV-2 and according to age. The primary efficacy end point was the development of symptomatic SARS-CoV-2 infection through day 28 in participants who did not have SARS-CoV-2 infection (as measured by reverse-transcriptase-quantitative polymerase-chain-reaction assay) or previous immunity (seronegativity). RESULTS: copies per milliliter) was shorter (0.4 weeks and 1.3 weeks, respectively). No dose-limiting toxic effects of REGEN-COV were noted. CONCLUSIONS: Subcutaneous REGEN-COV prevented symptomatic Covid-19 and asymptomatic SARS-CoV-2 infection in previously uninfected household contacts of infected persons. Among the participants who became infected, REGEN-COV reduced the duration of symptomatic disease and the duration of a high viral load. (Funded by Regeneron Pharmaceuticals and others; ClinicalTrials.gov number, NCT04452318.).