Regeneron antibody cocktail cut COVID-19 deaths in some cases: research

Oxford University on Wednesday released a study that finds that a COVID-19 antibody cocktail created by Regeneron reduces the risk of death due to the coronavirus.

The treatment known as REGEN-COV, which was granted emergency use authorization in the U.S. in November, was found to be able to neutralize the COVID-19 virus’s ability to infect cells. The treatment uses a combination of the monoclonal antibodies casirivimab and imdevimab.

Of the patients that were observed in the study, the Regeneron cocktail reduced mortality by one-fifth among patients who were seronegative — had not developed an antibody response to the virus yet — when compared to similar patients who received normal care.

“There was clear evidence that the effect of treatment in seronegative patients differed from that in seropositive patients,” the study read. “For the seronegative patients, the duration of hospital stay was four days shorter (median 13 days vs. 17 days) among those allocated to the antibody combination than the usual care group, and the proportion of patients discharged alive by day 28 was greater.”

The researchers estimated, based on their observations, that treatment with Regeneron would result in six fewer deaths for every 100 patients who received the cocktail.

The treatment works by binding to two specific sites on the spike proteins found on the surface of COVID-19 virus cells, according to the study. It uses monoclonal antibodies that are lab-created versions of antibodies the human body creates naturally against pathogens.

“We now know that this antibody combination is not only bad for the virus but it is also good for the sickest patients who have failed to mount a natural immune response of their own. That is excellent news — it is the first time that any antiviral treatment has been shown to save lives in hospitalised COVID-19 patients,” Martin Landray, Oxford University professor of medicine and epidemiology, said.

The study was conducted from Sep. 18 to May 22 and included 9,785 patients that were hospitalized due to COVID-19. Follow-ups were completed for 99 percent of the patients involved.

The Regeneron cocktail was administered to former President Trump when he was hospitalized due to contracting COVID-19. In November, the Food and Drug Administration granted the treatment emergency use authorization for patients as young as 12 who are at risk of developing a severe illness.

American pharmaceutical company Eli Lilly similarly announced in January that it had found its own antibody cocktail — a combination of bamlanivimab and etesevimab — reduced hospitalizations and deaths due to COVID-19. The Biden administration later agreed to buy 100,000 doses of Eli Lilly’s antibody treatment.