REGEN-COV Antibody Cocktail Is Active Against SARS-CoV-2 Variants First Identified in the UK and South Africa

Regeneron Pharmaceuticals, Inc. announced that researchers in Dr. David Ho’s Columbia University lab and Regeneron scientists have independently confirmed that REGEN-COVTM (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.

The development and manufacturing of REGEN-COV has been funded in part with federal funds from the Biomedical Advanced Research and Development Authority (BARDA), part of the U.S. Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response, under OT number: HHSO100201700020C.

About the REGEN-COV Antibody Cocktail
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.

In November 2020, REGEN-COV received Emergency Use Authorization (EUA) from the FDA for the treatment of mild to moderate COVID-19 in adults, as well as in pediatric patients at least 12 years of age and weighing at least 40 kg, who have received positive results of direct SARS-CoV-2 viral testing and are at high risk for progressing to severe COVID-19 and/or hospitalization. The clinical evidence from Regeneron’s outpatient trial suggests that monoclonal antibodies such as casirivimab and imdevimab have the greatest benefit when given early after diagnosis and in patients who are seronegative and/or who have high viral load. The criteria for ‘high-risk’ patients are described in the Fact Sheet for Healthcare Providers. In the U.S., casirivimab and imdevimab are not authorized for use in patients who are hospitalized due to COVID-19 or require oxygen therapy, or for people currently using chronic oxygen therapy because of an underlying comorbidity who require an increase in baseline oxygen flow rate due to COVID-19.

Regeneron is collaborating with Roche to increase global supply of REGEN-COV. Regeneron is responsible for development and distribution of the treatment in the U.S., and Roche is primarily responsible for development and distribution outside the U.S. The companies share a commitment to making the antibody cocktail available to COVID-19 patients around the globe and will support access in low- and lower-middle-income countries through drug donations to be made in partnership with public health organizations.

About Regeneron
Regeneron is a leading biotechnology company that invents life-transforming medicines for people with serious diseases. Founded and led for over 30 years by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to eight FDA-approved treatments and numerous product candidates in development, almost all of which were homegrown in our laboratories. Our medicines and pipeline are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, pain, infectious diseases and rare diseases.

Regeneron is accelerating and improving the traditional drug development process through our proprietary VelociSuite® technologies, such as VelocImmune®, which uses unique genetically-humanized mice to produce optimized fully-human antibodies and bispecific antibodies, and through ambitious research initiatives such as the Regeneron Genetics Center, which is conducting one of the largest genetics sequencing efforts in the world.