A phase 2/3 study of S-217622 in participants with SARS-CoV-2 infection (Phase 3 part).

In a post hoc analysis of the phase 2b study, compared with placebo, ensitrelvir demonstrated a reduced time to resolution of 5 symptoms in patients with mild-to-moderate COVID-19. Through this study, we intend to validate and establish the efficacy and safety of ensitrelvir in patients with mild-to-moderate COVID-19.