Regeneron’s monoclonal antibodies, casirivimab and imdevimab (REGEN-COV), reduced risk of death by 20% in patients hospitalized with COVID-19 who had not mounted their own immune response.
Regeneron announced today its investigational monoclonal antibodies, casirivimab and imdevimab (REGEN-COV), reported positive data from its phase 3 RECOVERY trial, which has prompted the company to seek an expansion of its Food and Drug Administration (FDA) Emergency Use Authorization (EUA) to include appropriate hospitalized patients.
The study’s results demonstrated that adding 8000 mg of casirivimab and imdevimab it reduced risk of death by 20% in patients hospitalized with COVID-19 who had not mounted their own immune response.
"Definitive Phase 3 trials have now demonstrated that REGEN-COV can alter the course of COVID-19 infection from prevention, to very early infection, all the way through to when patients are on a ventilator in the hospital," RegeneronPresident and Chief Scientific Officer George Yancopoulos, MD, PhD, said.
The trial was conducted in the United Kingdom and was conducted with patients who had not previously mounted a natural antibody response on their own against SARS-CoV-2, compared to usual care.
Among seronegative patients in the RECOVERY trial, the median duration of hospital stay was 4 days shorter in the REGEN-COV group (13 days versus 17 days), and the proportion of patients discharged alive by day 28 was greater (64% versus 58%; RR: 1.19; 95% CI: 1.08-1.30). Among the seronegative patients not on invasive mechanical ventilation at baseline, the risk of progressing to the composite endpoint of invasive mechanical ventilation or death was lower among the REGEN-COV group than the usual care group (30% versus 37%; RR: 0.83; 95% CI: 0.75-0.92). No such benefits were seen in the overall trial population (combining patients with negative, positive, or unknown serostatus).
Regeneron reports its treatment retains potency against variants including the Gamma (P.1, Brazilian), Beta (B.1.351, South Africa), and Delta (B.1.162.2 India) variants.
Previously reported data showed the treatment retained potency against some of these variants.
This follows an FDA EUA for Regeneron’s treatment last fall for the combined treatment of mild to moderate COVID-19.
No timeline has been yet established for this new potential EUA expansion.