The US Food and Drug Administration (FDA) has expanded the Emergency Use Authorization (EUA) for Regeneron Pharmaceuticals’ investigational antibody cocktail, REGEN-COV (casirivimab and imdevimab) to prevent Covid-19.

REGEN-COV is a combination of two monoclonal antibodies, casirivimab and imdevimab, that can hinder SARS-CoV-2 infectivity.

The updated authorisation allows the use of REGEN-COV for post-exposure prophylaxis in individuals at increased risk for progression to severe Covid-19, who are not completely vaccinated or may not have a proper response to vaccines.

In addition, the therapy can be used in people who were exposed to a person infected with SARS-CoV-2, or who are at increased risk of exposure to an infected person in an institutional setting, including nursing homes or prisons.

Regeneron noted that the antibody cocktail can be given every month to people who need repeated doses for ongoing exposure.

Subcutaneous injection or intravenous infusion of REGEN-COV is authorised for post-exposure prophylaxis.

In November last year, the antibody cocktail obtained FDA EUA for the treatment of mild to moderate Covid-19 patients who are at high risk for progressing to severe Covid-19 and/or hospitalisation.

The latest indication is apart from the EUA granted for the use of a reduced dose – 1,200mg – of REGEN-COV in June this year.

Regeneron Pharmaceuticals president and chief scientific officer George Yancopoulos said: “Today’s FDA authorisation enables certain people at high risk of developing severe Covid-19 infection to access REGEN-COV if they have been exposed to the virus – the first time an antibody treatment has been authorised for this purpose.

“With this authorisation, the FDA specifically highlights the needs of immunocompromised people, including those taking immunosuppressive medicines, who may not mount an adequate response to vaccination, who are exposed to a person with Covid-19 or are in an institutional setting and are at high risk of exposure because of infection occurring in the same setting.”

The expanded EUA for post-exposure prophylaxis is based on results from Phase III clinical trial which demonstrated REGEN-COV’s ability to lower the risk of symptomatic Covid-19 infections by 81% in close contacts of SARS-CoV-2-infected people.

Furthermore, the company noted that REGEN-COV is not indicated for pre-exposure prophylaxis for Covid-19 prevention and is not an alternative for vaccination.