Reigeneron said Tuesday that his monoclonal antibody cocktail prevented Covid-19 in a clinical trial.
The news, released via a press release, reflects similar news from Eli Lilly last week that his monoclonal antibody prevents symptomatic Covid-19 infections in nursing homes.
The results represent the first 400 volunteers of the study run by the National Institute of Allergy and Infectious Diseases (NIAID), and still enroll patients. The volunteers are at high risk for infection because they lived in the same household as a Covid-19 patient. Half of the patients received a placebo, and the other half received 1.2 grams of casirivimab and imdevimab, Regeneron’s antibodies.
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While eight of the 223 patients in the placebo group developed Covid symptoms and tested positive for the virus, none of the 186 patients who received the antibody did so. Volunteers who received the antibody were also less likely to be asymptomatic carriers of the SARS-CoV-2 virus, which causes Covid-19. Twenty-three volunteers in the placebo group tested positive for the virus, compared with 10 in the antibody group, a 50% reduction.
It also found that infections in volunteers who received the antibody were less serious than those who did not, the company said. Infected volunteers in the placebo group had, on average, more than 100 times higher peak viral loads. Infections in the antibody group lasted no longer than a week, while 40% of the infections in the placebo group lasted three to four weeks.
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Adverse events were less common among those who received the antibody cocktail, and were 18% in the placebo group and 12% in the antibody group. This was due to the negative effects of the virus. Two percent of those in both groups had reactions at the injection site.
Regeneron chief scientist George Yancopoulos said in a statement that the antibody, even with the available vaccines, can help break the chain of infection, and that it can be useful for individuals who are immune-boosted or cannot be vaccinated.
Regeneron was able to formulate the antibody so that it could be given as an injection, instead of being administered intravenously. This will make the antibody easier for healthcare workers.
The results were not reviewed or published in an academic journal.