A formulation of SARS-CoV-2 Spike protein-neutralising antibodies.

Phase of research

Emergency use authorization

How it helps


Drug status


Supporting references
Contradictory references
Clinical trials

General information

REGN-COV2 is a SARS-CoV-2 (Spike) neutralising antibody cocktail. It contains equal amounts of casirivimab and imdevimab antibodies (Weinreich et al., 2020).

On November 21, 2020, the FDA issued an Emergency Use Authorization (EUA) for emergency use of REGEN-COV (casirivimab and imdevimab,
administered together) for the treatment of mild to moderate COVID-19 in adults and pediatric patients (12 years of age and older weighing at least 40 kg) with positive results of direct SARS-CoV-2 viral testing, and who are at high risk for progressing to severe COVID-19 and/or hospitalization. 

On March 23, 2021, Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) announced positive topline results from the largest trial to date assessing a COVID-19 treatment in infected non-hospitalized patients. The Phase 3 trial shows that the REGEN-COV™ (casirivimab with imdevimab) antibody cocktail reduced hospitalization or death by 70%. 

On August 20, 2021, the MHRA has issued a Conditional Marketing Authorisation for REGN-COV2 (Ronapreve) in Great Britain and a temporary regulation authorisation for Northern Ireland.



Marketed as

Ronapreve; REGEN-COV

Supporting references

Link Tested on Impact factor Notes Publication date DB entry date
Compassionate use of REGN-COV2 in the treatment of COVID-19 in a patient with impaired humoral immunity
Spike protein IL-1 Protein factor Case report Antibody Mixed substance
An X-linked agammaglobulinaemia patient N/A

In a patient with X-linked agammaglobulinemia, clinical/immunological response to anakinra was not satisfactory. Long-term immunosuppression led to a secondary pulmonary infection. Administration of REGN-COV2 formulation led to SARS-CoV-2 PCR negativity and COVID-19 convalescence. Sample size: 1. Dosage: 1200 mg of REGN10933 and 1200 mg of RGN10987. 

Aug/19/2021 Jul/12/2022
In vitro and in vivo preclinical studies predict REGEN-COV protection against emergence of viral escape in humans
Preprint Antibody
HEK293T cells, hamsters

This study demonstrates that a combination of noncompeting antibodies not only provides full coverage against currently circulating variants but also protects against emergence of new such variants and their potential seeding into the population in a clinical setting.

Mar/23/2021 Mar/23/2021
SARS-CoV-2 variants B.1.351 and P.1 escape from neutralizing antibodies
Antibody In vitro Mixed substance Peptide RNA Small molecule Spike protein
Caco-2 cells; Vero cells; Sera of vaccinated individuals; (VSV) SARS-CoV-2 Spike-pseudotyped virus (WT, B.1.1.7, B.1.351, ant P.1 variants) 38.64

REGN-COV2 displayed in vitro inhibition of SARS-CoV-2 Spike-pseudotyped virus infection for all tested emergent Spike variants (B.1.1.7, B.1.351, and P.1).

Mar/20/2021 Apr/05/2021
REGN-COV2, a Neutralizing Antibody Cocktail, in Outpatients with Covid-19
Antibody Mixed substance Phase I clinical trial Phase II clinical trial Randomized controlled double-blind trial Spike protein
Outpatients 74.70

The antibody cocktail was generally well tolerated and reduced viral load in COVID-19 outpatients, especially those with high viral loads at baseline and patients whose immune response had not been initiated at the time of antibody administration. Sample size: 84 (high dose) + 80 (low dose) + 88 placebo (completed the trial). Dosage: 2.4 g (low) or 8 g (high). Endpoints: Change in viral load; proportion of patients with a COVID-19-related hospital visit by day 29.

Dec/17/2020 Dec/25/2020

Clinical trials

ID Title Status Phase Start date Completion date
NCT04617535 Compassionate Use of REGN-COV2 for the Treatment of COVID-19 Available Jan/01/1970 Jan/01/1970