Regeneron’s COVID-19 monoclonal antibody cocktail that was used to treat President Donald Trump has finally received Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration (FDA).
Late Friday, the FDA gave the green light to Regeneron's REGN-COV2, a combination of casirivimab and imdevimab. The treatment was authorized for use in mild to moderate COVID-19 patients age 12 and above, who have tested positive for the virus and are at high risk for progressing to severe COVID-19 and/or hospitalization. REGN-COV2 is not authorized for use in patients who are hospitalized or require oxygen therapy due to COVID-19, 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 said clinical data has shown that monoclonal antibodies such as REGN-COV2 are most effective when given to a patient shortly after diagnosis, and in patients who have not yet mounted their own immune response or who have high viral load. In October, the company released Phase II/III data that showed treatment with REGN-COV2 significantly reduced viral load and need for additional medical visits in outpatients with COVID-19. Following the data, the company submitted its antibody treatment for EUA.
The combination of casirivimab and imdevimab, two non-competing antibodies, are thought to bind to the receptor-binding domain of spike protein on the SARS-CoV-2 virus. This decreases the ability of mutant viruses to avoid treatment and protects against spike variants that have evolved in the human population.
Regeneron’s monoclonal antibody is the second such treatment granted EUA for COVID-19. Earlier this month, the FDA granted EUA to Eli Lilly and AbCellera for their investigational antibody, bamlanivimab (LY-CoV555). Bamlanivimab is a neutralizing IgG1 monoclonal antibody (mAb) directed against the spike protein of SARS-CoV-2. It is designed to block viral attachment and entry into human cells, which should neutralize the virus, and potentially prevent and treat COVID-19.
Regeneron Chief Scientific Officer George D. Yancopoulos said REGN-COV2 is designed to mimic what a well-functioning immune system does by using very potent antibodies to neutralize the virus. Clinical study of the antibody cocktail in more than 800 non-hospitalized patients showed significant reductions in viral levels, Yancopoulos said.
“This benefit was greatest in patients most at risk for poor outcomes due to high viral load, ineffective immune response at baseline or pre-existing risk factors. We are encouraged that no variants resistant to the cocktail were identified in the clinical trial analyses to date, which is consistent with our preclinical findings,” Yancopoulos said in a statement.
Leonard S. Schleifer, president and chief executive officer of Regeneron, said the EUA for REGN-COV2 is an important step in the ongoing fight against COVID-19, which has infected more than 58 million people across the globe and more than 12 million in the United States. Schleifer added that the authorization provides another option for treating high-risk patients in the early stages of infection.
Schleifer acknowledged that demand for REGN-COV2 may exceed supply at first. But, manufacturing will be ramped up to meet those demands. In August, Regeneron and Roche partnered to bolster manufacturing of REGN-COV2. The collaboration is expected to increase supply of REGN-COV2 to at least three and a half times the current capacity, with the potential for even further expansion, the partners said at the time. Regeneron now expects to have REGEN-COV2 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.
Through Operation Warp Speed, the U.S. 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 REGEN-COV2 to Amerisource Bergen, a national distributor, which will distribute the therapy as directed by the government, the company said.