Analysis of the first 275 patients in a trial of the REGN-COV2 antibody cocktail showing reductions in viral load and the time to alleviate symptoms in non-hospitalized patients with COVID-19. Greatest improvements were seen with patients that had not mounted their own effective immune response prior to treatment.
The mean time-weighted-average change from baseline nasopharyngeal viral load through Day 7 in the seronegative (no measurable antiviral antibodies) group was a 0.60 log10 copies/mL greater reduction (p
=0.03) in patients treated with high dose, and a 0.51 log10 copies/mL greater reduction (p
=0.06) in patients treated with low dose, compared to placebo. In the overall population, there was a 0.51 log10 copies/mL greater reduction (p
=0.0049) in patients treated with high dose, and a 0.23 log10 copies/mL greater reduction (p
=0.20) in patients treated with low dose, compared to placebo.
Among seronegative patients, median time to symptom alleviation (defined as symptoms becoming mild or absent) was 13 days in placebo, 8 days in high dose (p
=0.22), and 6 days in low dose (p
Adverse reactions were similar with treatment and placebo. There were no deaths.Efficacy is variant dependent. In Vitro research suggests a lack of efficacy for omicron [Liu, Sheward, Tatham, VanBlargan].
Regeneron et al., 29 Sep 2020, Randomized Controlled Trial, USA, preprint, 1 author.