The authors showed that the Regeneron antibody cocktail has a low incidence of side effects and a profound and rapid effect on viral load, with most reduction occurring within 48 hours, even in patents with the highest viral loads, which would presumably be at higher risk of death. The neutralizing antibody titers in the trial patents were more than 1000 times the titers achievable with convalescent plasma from previously ill patients who had recovered. Order of authorship in the original publication: Weinreich, Sivapalasingam, Norton et al. Available from PubMedCentral at this link.

(Thanks to Juan Weiss for this reference and its interpretation.)