Casirivimab/imdevimab

On 21 November 2020, the U.S. Food and Drug Administration (FDA) issued an emergency use authorization (EUA) for casirivimab and imdevimab to be administered together for the treatment of mild to moderate COVID-19 in people twelve years of age or older weighing at least 40 kilograms (88 lb) with positive results of direct SARS-CoV-2 viral testing and who are at high risk for progressing to severe COVID-19.[2] This includes those who are 65 years of age or older or who have certain chronic medical conditions.[2] Casirivimab and imdevimab must be administered together by intravenous (IV) infusion.[2]

In a clinical trial of people with COVID-19, casirivimab and imdevimab, administered together, were shown to reduce COVID-19-related hospitalization or emergency room visits in people at high risk for disease progression within 28 days after treatment when compared to placebo.[2] The safety and effectiveness of this investigational therapy for use in the treatment of COVID-19 continues to be evaluated.[2]

Casirivimab and imdevimab are not authorized for people who are hospitalized due to COVID-19 or require oxygen therapy due to COVID-19.[2] A benefit of casirivimab and imdevimab treatment has not been shown in people hospitalized due to COVID-19.[2] Monoclonal antibodies, such as casirivimab and imdevimab, may be associated with worse clinical outcomes when administered to hospitalized people with COVID-19 requiring high flow oxygen or mechanical ventilation.[2]

Although Regeneron is headquartered in Tarrytown, New York (near New York City), REGN-COV2 is manufactured at the company's primary U.S. manufacturing facility in Rensselaer, New York (near the state capital at Albany).[8] In September 2020, to free up manufacturing capacity for REGN-COV2, Regeneron began to shift production of its existing products from Rensselaer to the Irish city of Limerick.[9]

Regeneron has a deal in place with Hoffmann-La Roche to manufacture and market REGN-COV2 outside the United States.[10]

The data supporting the emergency use authorization (EUA) for casirivimab and imdevimab are based on a randomized, double-blind, placebo-controlled clinical trial in 799 non-hospitalized adults with mild to moderate COVID-19 symptoms.[2] Of these participants, 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.[2]

The prespecified primary endpoint for the trial was time-weighted average change in viral load from baseline.[2] Viral load reduction in participants treated with casirivimab and imdevimab was larger than in participants treated with placebo at day seven.[2] 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.[2] For participants at high risk for disease progression, hospitalizations and emergency room visits occurred in 3% of casirivimab and imdevimab-treated participants on average compared to 9% in placebo-treated participants.[2] The effects on viral load, reduction in hospitalizations and ER visits were similar in participants receiving either of the two casirivimab and imdevimab doses.[2]

The EUA was issued to Regeneron Pharmaceuticals Inc.[2]

On 2 October 2020, Regeneron Pharmaceuticals announced that US President Donald Trump had received "a single 8 gram dose of REGN-COV2" after testing positive for SARS-CoV-2.[11][12] The drug was provided by the company in response to a "compassionate use" (temporary authorization for use) request from the president's physicians.[11]

As of September 2020, REGN-COV2 is being evaluated as part of the RECOVERY Trial.[13]

• Bamlanivimab, another monoclonal antibody treatment for COVID-19.

• "Casirivimab and Imdevimab EUA Letter of Authorization" (PDF). U.S. Food and Drug Administration (FDA).
• "Frequently Asked Questions on the Emergency Use Authorization of Casirivimab + Imdevimab" (PDF). U.S. Food and Drug Administration (FDA).
• "Fact Sheet For Patients, Parents And Caregivers Emergency Use Authorization (EUA) Of Casirivimab And Imdevimab For Coronavirus Disease 2019 (COVID-19)" (PDF). U.S. Food and Drug Administration (FDA).
• "Fact Sheet For Health Care Providers Emergency Use Authorization (EUA) Of Casirivimab And Imdevimab" (PDF). U.S. Food and Drug Administration (FDA).