Regeneron announced today that its antibody cocktail REGEN-COV can be used as a passive vaccine to prevent COVID-19 in people who are at high risk of infection.
The ongoing phase 3 trial is evaluating the cocktail, which contains the two monoclonal antibodies casirivimab and imdevimab, for the prevention of COVID-19 in high-risk populations.
The first exploratory analysis of 400 evaluable participants found that passive vaccination with REGEN-COV resulted in 100% prevention of symptomatic COVID-19 infections.
On top of that, the cocktail led to approximately 50% lower overall rates of infection – with infections occurring with REGEN-COV therapy all being asymptomatic.
Regeneron added that the infections observed in the placebo group had more than 100-fold higher peak viral loads compared to REGEN-COV-treated patients.
While appropriately 40% of COVID-19 infections in the placebo group lasted three to four weeks, infections in the REGEN-COV group lasted no more than one week.
“Even with the emerging availability of active vaccines, we continue to see hundreds of thousands of people infected daily, actively spreading the virus to their close contacts,” said George Yancopoulos, president and chief scientific officer, Regeneron.
“The REGEN-COV antibody cocktail may be able to help break this chain by providing immediate passive immunity to those at high risk of infection, in contrast to active vaccines which take weeks to provide protection,” he added.
In November 2020, Regeneron’s antibody cocktail received an emergency use authorisation (EUA) from the US Food and Drug Administration (FDA) for the treatment of mild to moderate COVID-19 in patients aged at least 12 years old who weigh at least 40kg and are at high risk of progressing to severe COVID-19 and/or hospitalisation.
Under the EUA, the recommended dose for REGEN-COV is 1,200mg of casirivimab and 1,200mg of imdevimab administered as a single intravenous infusion.
While vaccines are seen as the key tool in the fight to end the COVID-19 pandemic, delays due to manufacturing and scale-up issues have highlighted the ongoing need for effective therapeutics to combat the novel coronavirus.
Earlier this week, Eli Lilly announced that its neutralising antibody bamlanivimab significantly reduced the risk of COVID-19 infection among residents and staff in care homes.
The results from the phase 3 BLAZE-3 COVID-19 prevention trial suggested that bamlanivimab-treated participants had up to an 80% lower risk of contracting COVID-19 compared to residents in the same facility who did not receive the antibody.