REGEN-COV Shows Reduced Hospitalization and Death in Non-hospitalized COVID-19 Patients

REGEN-COV, a cocktail of two monoclonal antibodies (casirivimab with imdevimab) created by Regeneron Pharmaceuticals, has shown that it significantly reduces the risk of hospitalization or death in non-hospitalized patients who are infected with COVID-19.

The company announced the results from its phase 3 trial which assessed the treatment in high-risk non-hospitalized COVID-19 patients. The trial included 4,567 participants, all of whom had at least one risk factor including obesity (58%), age 50 years (51%) and cardiovascular disease, including hypertension (36%).

Findings from the trial demonstrated that REGEN-COV reduced the risk of hospitalization or death by 70% with 1,200 mg given intravenously (IV) and by 71% with 2,400 mg given through IV compared to a placebo. The cocktail also significantly shortened the duration of symptoms by 4 days.

Additionally, an accompanying phase 2 trial testing for dose-ranging virology, found that even the lowest doses tested (IV: 300 mg; subcutaneous [SC]: 600 mg) had significant viral load reductions over the first 7 days of the study, comparable to the 2,400 mg and 1,200 mg IV doses.

"This is a landmark moment in the fight against COVID-19 as this large well-controlled trial provides conclusive results demonstrating that REGEN-COV can dramatically reduce the risk of hospitalization and death in the outpatient setting," Suraj Saggar, an investigator on the trial and the Chief of Infectious Disease at Holy Name Medical Center said. "With so many people still getting infected, as well as recent data showing that REGEN-COV addresses emerging variants, these data underscore the need to rapidly adopt REGEN-COV as standard-of-care to offer high-risk patients their best chance to reduce serious consequences like hospitalization or death."

Last week, the US Food and Drug Administration (FDA) updated its fact sheets for monoclonal antibodies that are currently approved under an emergency use authorization (EUA). The revisions note that REGEN-COV retains potency against the main variants of concern known to be circulating within the US.

Regeneron expects to provide 750,000 doses of the cocktail at the 2,400 mg dose level. However, if the 1,200 mg dose is approved for an EUA, they will be able to provide approximately 1.25 million doses.