Roche and Regeneron’s COVID-19 antibody cocktail REGEN-COV reduced the risk of symptomatic infections by 81% in a phase 3 prevention trial.
The phase 3 2069A trial – run jointly with the US National Institute of Allergy and Infectious Diseases (NIAID) – evaluated the ability of REGEN-COV (casirivimab with imdevimab) to reduce the risk and burden of COVID-19 infection among household contacts of individuals infected with the SARS-CoV-2 virus.
The trial enrolled a total of 1,505 people who were not infected with SARS-CoV-2 at baseline and randomised to receive either one dose of REGEN-COV (1,200mg administered subcutaneously) or placebo.
For those treated with REGEN-COV and who experienced a symptomatic infection, their symptoms resolved in one week compared to three weeks with placebo, with infected individuals also clearing the virus faster with REGEN-COV.
In addition, Roche and Regeneron also announced results from the phase 3 2069B trial, which found that REGEN-COV reduced the overall risk of progressing to symptomatic COVID-19 by 31% and by 76% after the third day among recently infected, asymptomatic COVID-19 patients.
On top of reducing the risk of symptomatic infections, the total number of weeks patients experienced symptoms decreased by 45% with REGEN-COV treatment, with viral burden also dropping by over 90%.
“With more than 60,000 Americans continuing to be diagnosed with COVID-19 every day, the REGEN-COV antibody cocktail may help provide immediate protection to unvaccinated people who are exposed to the virus, and we are also working to understand its potential to provide ongoing protection for immunocompromised patients who may not respond well to vaccines,” said George Yancopoulos, president and chief scientific officer at Regeneron.
“We thank the individuals, investigators and our collaborators involved in the trial, and look forward to rapidly discussing these results with regulatory authorities,” he added.
Roche and Regeneron are also evaluating REGEN-COV in clinical trials across a number of settings for the treatment and prevention of COVID-19.
This includes evaluating REGEN-COV for the treatment of non-hospitalised and certain hospitalised patients.
So far (as of April 2021) over 25,000 people have participated in clinical trials involving REGEN-COV, according to Regeneron.
REGEN-COV is currently available in the US under an emergency use authorisation (EUA) issued by the Food and Drug Administration (FDA) for the treatment of high-risk mild-to-moderate COVID-19 in adults, as well as paediatric patients at least 12 years of age and weighing at least 40kg.