On Aug. 30, 2021, the Mayo Clinic reported that in an observational study the combination of casirivimab and imdevimab – two monoclonal antibody treatments under Food and Drug Administration emergency use authorization – kept high-risk patients out of the hospital when infected with mild to moderate COVID-19.

Nearly 1,400 Mayo Clinic patients were enrolled in the study ― 696 who received the drug combo between December 2020 and early April and an equal matched cohort who did not receive it. Their status was evaluated at 14, 21 and 28 days after treatment. At each point, the numbers for hospitalization were significantly lower in the treated group. The findings appeared in The Lancet’s EClinicalMedicine.