One thousand and two hundred adult subjects with mild/moderate COVID-19 (including subjects with high risk factors for progression into severe cases) are planned to be enrolled and randomized in a ratio of 1:1 into the test group or the placebo group. Randomization and stratification factors include clinical type (mild vs. moderate) of COVID-19, high risk factors for severe disease (with vs. without), history of SARS-CoV-2 vaccination or infection (yes vs. no). Subjects in the test group will receive STI-1558, and subjects in the placebo group will receive STI-1558 placebo. STI-1558 and STI-1558 placebo will be orally administered under fasting condition twice daily (BID) for 5 days (10 doses in total) at a dose of 600 mg and 0 mg, respectively; the two doses administered will be at a minimum interval of 8 hours (≥8 h). Efficacy and safety will be assessed until D29 after the first dose.
This is a multicenter, randomized, double-blind, placebo-controlled phase III clinical study to evaluate the efficacy and safety of STI-1558 in adult subjects with mild/moderate COVID-19. One thousand and two hundred adult subjects with mild/moderate COVID-19 (including subjects with high risk factors for progression into severe cases) are planned to be enrolled and randomized in a ratio of 1:1 into the test group or the placebo group (600 in the test group and 600 in the placebo group).