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 A Marovich, Peijie Hou, Ingeborg Heirman, John D Davis, Kenneth C Turner, Divya Ramesh, Adnan Mahmood, Andrea T Hooper, Jennifer D Hamilton, Yunji 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
New England Journal of Medicine, doi:10.1056/nejmoa2109682
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-transcriptasequantitative polymerase-chain-reaction assay) or previous immunity (seronegativity).
RESULTS Symptomatic SARS-CoV-2 infection developed in 11 of 753 participants in the REGEN-COV group (1.5%) and in 59 of 752 participants in the placebo group (7.8%) (relative risk reduction [1 minus the relative risk], 81.4%; P<0.001). In weeks 2 to 4, a total of 2 of 753 participants in the REGEN-COV group (0.3%) and 27 of 752 participants in the placebo group (3.6%) had symptomatic SARS-CoV-2 infection (relative risk reduction, 92.6%). REGEN-COV also prevented symptomatic and asymptomatic infections overall (relative risk reduction, 66.4%). Among symptomatic infected participants, the median time to resolution of symptoms was 2 weeks shorter with REGEN-COV than with placebo (1.2 weeks and 3.2 weeks, respectively), and the duration of a high viral load (>10 4 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.
Appendix The authors' full names and academic degrees are as follows: Meagan P. O'Brien, M.D., Eduardo Forleo-Neto, M.D., Bret J. Musser, Ph.D., Flonza Isa, M.D., Kuo-Chen Chan, Ph.D., Neena Sarkar, Ph.D., Katharine J. Bar
References
Baum, Fulton, Wloga, Antibody cocktail to SARS-CoV-2 spike protein prevents rapid mutational escape seen with individual antibodies, Science
Copin, Baum, Wloga, The monoclonal antibody combination REGEN-COV protects against SARS-CoV-2 mutational escape in preclinical and human studies, Cell
Madewell, Yang, Longini, Jr, Halloran et al., Household transmission of SARS-CoV-2: a systematic review and meta-analysis, JAMA Netw Open
Wang, Nair, Liu, Antibody resistance of SARS-CoV-2 variants B.1.351 and B.1.1.7, Nature
Weinreich, Sivapalasingam, Norton, Fact sheet for health care providers: Emergency Use Authorization (EUA) of REGEN-COV (casirivimab and imdevimab)
Weinreich, Sivapalasingam, Norton, REGEN-COV antibody cocktail clinical outcomes study in Covid-19 outpatients,
doi:10.1101/2021.05.19
Weinreich, Sivapalasingam, Norton, REGN-COV2, a neutralizing antibody cocktail, in outpatients with Covid-19, N Engl J Med
Wu, Zhao, Yu, A new coronavirus associated with human respiratory disease in China, Nature
Zhu, Zhang, Wang, A novel coronavirus from patients with pneumonia in China, N Engl J Med