Toggle Main Menu Toggle Search

Open Access padlockePrints

Casirivimab and imdevimab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Lookup NU author(s): Emily Hunter, Professor Anthony De SoyzaORCiD, Dr Rachel Agbeko, Dr Ken BakerORCiD, Dr Quentin Campbell Hewson, Dr Christopher DuncanORCiD, Professor Marieke Emonts-le ClercqORCiD, Andrea Fenn, Dr Aidan Hanrath, Kath Houghton, Douglas Jerry, Gerry Jones, Sinead Kelly, Dr Nicholas Lane, Dr Jim Macfarlane, Dr Iain McCullagh, Sam McDonald, Dr Ross Obukofe, Jess Parker, Dr Alexandra Patience, Dr Brendan PayneORCiD, Dr David Price, Dr Salman Razvi, Professor Steve RobsonORCiD, Dr Emily StephensonORCiD, Dr Sophie West, Dr Edwin Wong, Fiona Yelnoorkar



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Background: Casirivimab and imdevimab are non-competing monoclonal antibodies that bind to two different sites on the receptor binding domain of the SARS-CoV-2 spike glycoprotein, blocking viral entry into host cells. We aimed to evaluate the efficacy and safety of casirivimab and imdevimab administered in combination in patients admitted to hospital with COVID-19. Methods: RECOVERY is a randomised, controlled, open-label platform trial comparing several possible treatments with usual care in patients admitted to hospital with COVID-19. 127 UK hospitals took part in the evaluation of casirivimab and imdevimab. Eligible participants were any patients aged at least 12 years admitted to hospital with clinically suspected or laboratory-confirmed SARS-CoV-2 infection. Participants were randomly assigned (1:1) to either usual standard of care alone or usual care plus casirivimab 4 g and imdevimab 4 g administered together in a single intravenous infusion. Investigators and data assessors were masked to analyses of the outcome data during the trial. The primary outcome was 28-day all-cause mortality assessed by intention to treat, first only in patients without detectable antibodies to SARS-CoV-2 infection at randomisation (ie, those who were seronegative) and then in the overall population. Safety was assessed in all participants who received casirivimab and imdevimab. The trial is registered with ISRCTN (50189673) and (NCT04381936). Findings: Between Sept 18, 2020, and May 22, 2021, 9785 patients enrolled in RECOVERY were eligible for casirivimab and imdevimab, of which 4839 were randomly assigned to casirivimab and imdevimab plus usual care and 4946 to usual care alone. 3153 (32%) of 9785 patients were seronegative, 5272 (54%) were seropositive, and 1360 (14%) had unknown baseline antibody status. 812 (8%) patients were known to have received at least one dose of a SARS-CoV-2 vaccine. In the primary efficacy population of seronegative patients, 396 (24%) of 1633 patients allocated to casirivimab and imdevimab versus 452 (30%) of 1520 patients allocated to usual care died within 28 days (rate ratio [RR] 0·79, 95% CI 0·69-0·91; p=0·0009). In an analysis of all randomly assigned patients (regardless of baseline antibody status), 943 (19%) of 4839 patients allocated to casirivimab and imdevimab versus 1029 (21%) of 4946 patients allocated to usual care died within 28 days (RR 0·94, 95% CI 0·86-1·02; p=0·14). The proportional effect of casirivimab and imdevimab on mortality differed significantly between seropositive and seronegative patients (p value for heterogeneity=0·002). There were no deaths attributed to the treatment, or meaningful between-group differences in the pre-specified safety outcomes of cause-specific mortality, cardiac arrhythmia, thrombosis, or major bleeding events. Serious adverse reactions reported in seven (<1%) participants were believed by the local investigator to be related to treatment with casirivimab and imdevimab. Interpretation: In patients admitted to hospital with COVID-19, the monoclonal antibody combination of casirivimab and imdevimab reduced 28-day mortality in patients who were seronegative (and therefore had not mounted their own humoral immune response) at baseline but not in those who were seropositive at baseline. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research.

Publication metadata

Author(s): RECOVERY Collaborative Group, Inc. The Newcastle Upon Tyne Hospitals NHS Foundation Trust, Hunter E, De Soyza A, Agbeko R, Baker K, Barr A, Cameron E, Campbell Hewson Q, Duncan C, Emonts M, Fenn A, Francis S, Glover Bengtsson J, Greenhalgh A, Hanrath A, Houghton K, Jerry D, Jones G, Kelly S, Lane N, Macfarlane J, McAlinden P, McCullagh I, McDonald S, Mohammed O, Obukofe R, Parker J, Patience A, Payne B, Price D, Razvi S, Robson S, Sanchez Gonzalez A, Stephenson E, Welton R, West S, Wong E, Yelnoorkar J

Publication type: Article

Publication status: Published

Journal: The Lancet

Year: 2022

Volume: 399

Issue: 10325

Pages: 665-676

Print publication date: 12/02/2022

Online publication date: 10/02/2022

Acceptance date: 02/04/2018

Date deposited: 03/03/2022

ISSN (print): 0140-6736

ISSN (electronic): 1474-547X

Publisher: The Lancet Publishing Group


DOI: 10.1016/S0140-6736(22)00163-5

PubMed id: 35151397


Altmetrics provided by Altmetric


Funder referenceFunder name