Regeneron Pharmaceuticals, Inc. received Emergency Use Authorization (EUA) from the U.S. FDA for its antibody cocktail casirivimab and imdevimab administered together (formerly known as REGN-COV2 or REGEN-COV2), a therapy currently being investigated for use in COVID-19.

Casirivimab and imdevimab are authorized to treat mild to moderate COVID-19 in adults and pediatric patients at least 12 years of age who have tested positive for SARS-CoV-2 and are at high risk for progressing to severe COVID-19 and/or hospitalization. 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 have not yet mounted their own immune response or who have high viral load.

The authorization is based on positive Phase 2 data announced in September and October from the first 799 adults in an ongoing randomized, double-blind, placebo-controlled trial of non-hospitalized patients with COVID-19. The therapy continues to be evaluated in Phase 2/3 trials. To date, more than 7,000 people have participated in casirivimab and imdevimab trials.

Production of monoclonal antibodies is a complex, time- and labor-intensive process that requires deep expertise. Regeneron rapidly scaled up production of casirivimab and imdevimab, beginning in the early days of the pandemic with support from the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response at the U.S. Department of Health and Human Services.

Regeneron now expects to have treatment doses ready for approximately 80,000 patients by the end of November, approximately 200,000 patients by the first week of January, and approximately 300,000 patients in total by the end of January 2021.

As part of Operation Warp Speed, in July the U.S. government and Regeneron signed an agreement for this initial supply of the casirivimab and imdevimab antibody cocktail. The U.S. government will coordinate with state authorities to allocate the antibody cocktail on a weekly basis based on the number of COVID-19 cases in each state. The government has committed to providing these 300,000 doses at no cost to patients, although healthcare facilities may charge fees related to administration. Regeneron will immediately begin shipping doses to Amerisource Bergen, a national distributor, which will distribute the therapy as directed by the government.

The FDA grants Emergency Use Authorization to medicines that may help diagnose, treat or prevent a life-threatening disease when adequate and approved alternatives are not available. The EUA is temporary and does not take the place of a formal biologics license application (BLA) submission review and approval process.