Regeneron Says Antibodies Show Success in Preventing COVID-19 Infections

By Zachary Stieber
Zachary Stieber
Zachary Stieber
Zachary Stieber covers U.S. news and stories relating to the COVID-19 pandemic. He is based in Maryland.
November 8, 2021 Updated: November 8, 2021

Monoclonal antibodies that have already proven successful in preventing hospitalizations in people who contract COVID-19 may also serve as protection against COVID-19 infection, according to new data.

Regeneron said its monoclonal antibody treatment reduced the risk of contracting the disease by 81.6 percent among uninfected persons.

The data comes from a phase three trial run by the company with the National Institute of Allergy and Infectious Diseases.

Researchers followed participants in the trial for eight months.

The trial already indicated the combination of the drugs casirivimab and imdevimab, together known as Regen-Cov, was successful in preventing COVID-19 infection in the month following administration.

The new data suggest the protection spans for over half a year.

“These results demonstrate that REGEN-COV has the potential to provide long-lasting immunity from SARS-CoV-2 infection, a result particularly important to those who do not respond to COVID-19 vaccines including people who are immunocompromised,” Dr. Myron Cohen, who leads the monoclonal antibody research at the National Institutes of Health-sponsored COVID Prevention Network, said in a statement released by Regeneron.

SARS-CoV-2 is another name for the CCP (Chinese Communist Party) virus, which causes COVID-19.

While some participants who received the antibodies did contract the illness, none were hospitalized due to COVID-19, compared to six people in the placebo group, researchers said. None of the participants who were treated with the drugs died from COVID-19.

Some of the participants from both arms received COVID-19 vaccines after the first month, including about 34 percent of those in the treatment arm.

Early results from the trial were reported in the New England Journal of Medicine but the new results have not yet been published in a peer-reviewed publication.

“We intend to rapidly share these additional data with regulatory authorities to help those in most need of protection from COVID-19,” Dr. George Yancopoulos, president and chief scientific officer at Regeneron, said in a statement.

Drug regulators previously authorized Regeneron’s monoclonal antibody treatment, but only to treat people who already have COVID-19 and are not in the hospital or in a specific set of post-exposure settings. Former President Donald Trump took the drug in late 2020 after testing positive for COVID-19.

Dr. Walid Gellad, director of the Center for Pharmaceutical Policy and Prescribing at the University of Pittsburgh, said on Twitter that the results indicate the monoclonal antibodies “clearly work.”

“Seems they should/will have a role in outbreaks in nursing home or other congregate setting, even with vaccination,” he said.

Zachary Stieber
Zachary Stieber covers U.S. news and stories relating to the COVID-19 pandemic. He is based in Maryland.