Viral and symptom rebound following anti-SARS-CoV-2 monoclonal antibody therapy in a randomized placebo-controlled trial

We explored viral and symptom rebound after COVID-19 amubarvimab/romlusevimab monoclonal antibody therapy vs placebo in the randomized ACTIV-2/A5401 trial. Participants underwent nasal SARS-CoV-2 PCR at study days 3, 7, 14, and 28. Viral rebound was defined as RNA ≥3 and ≥0.5 log10 copies/mL increase from day 3 or 7, and symptom rebound as hospitalization or any moderate/severe symptom for ≥2 days after initial symptom improvement. There was no difference in viral rebound (∼5%/arm) (analysis population n=713) or symptom rebound among participants who initially improved (hazard ratio 0.95 (95% CI 0.52, 1.75, analysis population) n=574);