Scientists find REGEN-COV antibody cocktail is active against SARS-COV-2 variants in UK & South Africa

Tarrytown, New YorkFriday, January 29, 2021, 13:00 Hrs  [IST]

Regeneron Pharmaceuticals announced that researchers in Dr. David Ho's Columbia University lab and Regeneron scientists have independently confirmed that REGEN-COV (casirivimab and imdevimab antibody cocktail) successfully neutralizes the circulating SARS-CoV-2 variants first identified in the UK (B.1.1.7) and South Africa (B.1.351). Columbia's findings were included in a paper posted to bioRxiv and submitted for peer-reviewed publication on the changing resistance of SARS-CoV-2 variants to antibody neutralization.

Both teams of researchers assessed in vitro neutralization potency of numerous covid-19 antibodies (including those that have received emergency authorization and those still in development) against various mutated strains of the virus. Although some antibody therapies were no longer effective against some of these variants, the REGEN-COV antibody cocktail continued to neutralize all variants tested. REGEN-COV, which consists of the highly potent neutralizing antibodies imdevimab (REGN10987) and casirivimab (REGN10933), retained its potent neutralizing capability against the B.1.1.7 variant, with both antibodies retaining their potency. REGEN-COV also retained its highly potent neutralizing capacity against the B.1.351 variant; imdevimab retained its potency against this variant, and, while casirivimab potency was reduced, it was still comparable to the potency that other single antibodies in development have against the original virus.

The variant first identified in Brazil (1.1.248) and recently seen in a patient in the United States contains the same receptor binding domain mutations as the B.1.351 variant, therefore REGEN-COV is expected to remain similarly potent. Regeneron is conducting additional preclinical research against this particular strain to confirm this.

“As we expected, the virus continues to mutate, and these data show the continued ability of REGEN-COV to neutralize emerging strains, further validating our multi-antibody cocktail approach to infectious diseases,” said George D. Yancopoulos, M.D., Ph.D., president and chief scientific officer at Regeneron. “With two complementary antibodies in one therapeutic, even if one has reduced potency, the risk of the cocktail losing efficacy is significantly diminished, since the virus would need to mutate in multiple distinct locations to evade both antibodies. Thanks to our proprietary VelocImmune technology, we have hundreds of additional potent, neutralizing antibodies in our labs that could form new combinations that might be useful against future variants. We are evaluating potential next steps with these novel candidates.”

“In the face of this daunting pandemic, we appreciate the open exchange of pre-publication data and the opportunity to confirm important findings with one of the world's leading academic laboratories," said Christos A. Kyratsous, Ph.D., vice president of Research, Infectious Diseases and Viral Vector Technologies at Regeneron.

REGEN-COV (casirivimab and imdevimab) is a cocktail of two monoclonal antibodies (also known as REGN10933 and REGN10987) and was designed specifically to block infectivity of SARS-CoV-2, the virus that causes COVID-19. The two potent, virus-neutralizing antibodies that form the cocktail bind non-competitively to the critical receptor binding domain of the virus's spike protein, which diminishes the ability of mutant viruses to escape treatment and protects against spike variants that have arisen in the human population, as detailed in Science.