Casirivimab/imdevimab authorized for ’mild to moderate’ Covid-19

Casirivimab and imdevimab, a monoclonal antibody combo developed by Regeneron Pharmaceuticals, Inc. for treatment of mild to moderate Covid-19, received an emergency use authorization (EUA) from the FDA on Nov. 21.

The antibody cocktail became a national focus when President Donald J. Trump touted it as a “cure” for Covid-19 after he received a 5-day course of it when he was hospitalized for treatment of Covid-19.

The EUA approved casirivimab/imdevimab (REGN-COV2) “to be administered together for the treatment of mild to moderate Covid-19 in adults and pediatric patients (12 years of age or older weighing at least 40 kilograms [about 88 pounds]) with positive results of direct SARS-CoV-2 viral testing and who are at high risk for progressing to severe Covid-19. This includes those who are 65 years of age or older or who have certain chronic medical conditions.”

The drug is not authorized for use in severely ill patients, such as hospitalized Covid-19 patients who require oxygen therapy, because the combination’s efficacy “has not been shown in patients hospitalized due to Covid-19. Monoclonal antibodies, such as casirivimab and imdevimab, may be associated with worse clinical outcomes when administered to hospitalized patients with Covid-19 requiring high flow oxygen or mechanical ventilation,” the FDA cautioned.

“The FDA remains committed to advancing the nation’s public health during this unprecedented pandemic. Authorizing these monoclonal antibody therapies may help outpatients avoid hospitalization and alleviate the burden on our health care system,” said FDA Commissioner Stephen M. Hahn, MD, in a prepared statement. The FDA said the EUA decision was based on findings from a “randomized, double-blind, placebo-controlled clinical trial in 799 non-hospitalized adults with mild to moderate Covid-19 symptoms. Of these patients, 266 received a single intravenous infusion of 2,400 milligrams casirivimab and imdevimab (1,200 mg of each), 267 received 8,000 mg casirivimab and imdevimab (4,000 mg of each), and 266 received a placebo, within three days of obtaining a positive SARS-CoV-2 viral test.

For latest news and updates

“The prespecified primary endpoint for the trial was time-weighted average change in viral load from baseline,” the agency wrote. “Viral load reduction in patients treated with casirivimab and imdevimab was larger than in patients treated with placebo at day seven. However, the most important evidence that casirivimab and imdevimab administered together may be effective came from the predefined secondary endpoint of medically attended visits related to Covid-19, particularly hospitalizations and emergency room visits within 28 days after treatment. For patients at high risk for disease progression, hospitalizations and emergency room visits occurred in 3% of casirivimab and imdevimab-treated patients on average compared to 9% in placebo-treated patients. The effects on viral load, reduction in hospitalizations and ER visits were similar in patients receiving either of the two casirivimab and imdevimab doses.”

Peggy Peck, Editor-in-Chief, BreakingMED™

Cat ID: 190

Topic ID: 79,190,190,926,192,46,927,151,725,928,925,934