Regeneron said it will seek expansion of the emergency use authorization for the drug, which is currently available in the United States to treat mild-to-moderate Covid-19 in people already infected with the coronavirus.
After 29 days, 11 people who received a single 1,200 mg dose of the treatment developed symptomatic Covid-19; 59 people who received a placebo developed symptomatic Covid-19. The drug provided 72% protection against symptomatic infections in the first week and 93% protection in subsequent weeks, Regeneron said. The data has not yet been peer reviewed or published.
Those who received the antibody cocktail and experienced a symptomatic infection resolved their symptoms in one week, the company said, compared to three weeks among those who received a placebo.
“Despite standard precautions to reduce transmission, nearly 10% of unvaccinated individuals living with an infected person developed symptomatic infections if they did not receive REGEN-COV,” Dr. Myron Cohen, who leads the monoclonal antibody efforts for the COVID Prevention Network and is the director of the Institute for Global Health and Infectious Diseases at the University of North Carolina at Chapel Hill, said in a statement. “If authorized, convenient subcutaneous administration of REGEN-COV could help control outbreaks in high-risk settings where individuals have not yet been vaccinated, including individual households and group living settings.”
Adverse events occurred in 20% of patients who received the antibody drug and 29% of those who received a placebo, Regeneron said. None of the participants who received the drug were hospitalized or went to the ER because of Covid-19 over the course of 29 days; four in the placebo group did so. None of the four deaths in the trial — two among those who received the drug and two who received a placebo — were due to Covid-19 or the drug.
Regeneron said it will request an expansion of its US Food and Drug Administration emergency use authorization to include Covid-19 prevention and as a subcutaneous shot. The drug is currently authorized to be administered as an IV, which takes longer and may be part of the reason why uptake of the treatment has been limited.
So far, Regeneron’s cocktail has been shown to be effective against coronavirus variants of concerns.