[24][25] On 2 October 2020, Regeneron Pharmaceuticals announced that then-US President Donald Trump had received "a single 8 gram dose of REGN-COV2" after testing positive for SARS-CoV-2.

[33] In September 2021, the World Health Organization urged producers and governments to address the drug's high cost and called for technology sharing to enable the manufacture of biosimilar versions.

[10][37] 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.

[9] 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.

[9] In June 2021, the EUA was revised to authorize "the use of the unapproved product, REGEN‑COV (casirivimab and imdevimab) co-formulated product and REGEN‑COV (casirivimab and imdevimab) supplied as individual vials to be administered together, for the treatment of mild to moderate COVID‑19 in people aged twelve years of age and 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 progression to severe COVID‑19, including hospitalization or death".

[40][41] In February 2021, the CHMP concluded that the combination, also known as REGN-COV2, can be used for the treatment of confirmed COVID‑19 in people who do not require supplemental oxygen and who are at high risk of progressing to severe COVID‑19.

[42] The Central Drugs Standards Control Organisation (CDSCO) in India, on 5 May 2021, granted an Emergency Use Authorization to Roche (Genentech)[23] and Regeneron[43] for use of the casirivimab/imdevimab cocktail in the country.

[46] In June 2021, preliminary results form the Recovery trial showed reduced mortality from 30% to 24% in people that had produced no antibodies themselves which were 33% of the total of participants.

[9] 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.

[9] The effects on viral load, reduction in hospitalizations and ER visits were similar in participants receiving either of the two casirivimab and imdevimab doses.