ObjectiveTo evaluate the efficacy and safety of pegylated interferon alpha-2b (PEG IFN-α2b) administered in conjunction with the standard of care (SOC) in subjects with moderate coronavirus disease-19 (COVID-19). MethodsIn this study, adult subjects with confirmed moderate COVID-19 were randomized in a 1:1 ratio to receive either PEG IFN-α2b + SOC or SOC alone. The primary endpoint was a two-point improvement in clinical status on Day 11, measured by the World Health Organization's seven-point ordinal scale. ResultsOf 250 subjects, 120 were randomized to the PEG IFN-α2b + SOC arm and 130 were randomized to the SOC arm. The results for the PEG IFN + SOC arms vs the SOC arm for the proportion of subjects with a two-point improvement in the seven-point ordinal scale were 80.36% vs 68.18% (P=0.037) on Day 8, 91.60% vs 92.56% (P=0.781) on Day 11, and 94.12% vs 95.93% (P=0.515) on Day 15. There was a time-dependent decrease in the biomarkers in both arms, and no clinically significant changes in laboratory parameters. The safety profile was similar in both arms. ConclusionPEG IFN-α2b induced early viral clearance, improved the clinical status, and decreased the duration of supplemental oxygen. It provides a viable treatment option and can limit the spread of severe acute respiratory syndrome coronavirus-2.