Regeneron’s COVID-19 Antibody Combo Cuts Symptomatic Infections

Regeneron Pharmaceuticals has said its COVID-19 antibody cocktail, REGEN-COV (casirivimab with imdevimab) reduced the risk of symptomatic infections by 81 percent in a late-stage trial.

The phase 3 study evaluated more than 1,500 uninfected individuals living in the same household as someone who had tested positive for SARS-CoV-2 over the prior four days, with participants receiving either 1,200 mg of REGEN-COV by subcutaneous injection or a placebo.

Those treated with the antibody combination who suffered from symptomatic infection generally saw their symptoms end in one week vs. three weeks for the placebo arm in the study conducted with the NIH’s National Institute of Allergy and Infectious Diseases (NIAID).

The combination therapy “could help control outbreaks in high-risk settings where individuals have not yet been vaccinated, including individual households,” said Myron Cohen, one of the study’s lead investigators.

In a separate phase 3 study conducted with the NIAID, the antibody combination reduced the overall risk of progressing to symptomatic COVID-19 by 31 percent over 29 days. That trial enrolled 204 asymptomatic COVID-19 patients who lacked antiviral antibodies. Patients who did progress to symptomatic infection saw a 45 percent reduction in the number of weeks they experienced symptoms, with the viral burden reduced by more than 90 percent, the company said. — Jason Scott