Multicenter, Single-Blind, Randomized Controlled Study of the Efficacy and Safety of Favipiravir and Nafamostat Mesilate in Patients with COVID-19 Pneumonia

To evaluate the efficacy and safety of nafamostat combined with favipiravir for coronavirus disease 2019.We conducted a multicenter, randomized, single-blind, placebo-controlled parallel assignment study in hospitalized patients with mild-to-moderate coronavirus disease 2019 pneumonia. Patients were randomly assigned to receive favipiravir alone (n=24) or nafamostat with favipiravir (n=21). Outcomes included changes in the WHO Clinical Progression Scale score, time to improvement in body temperature, and improvement in oxygen saturation (SpOThere was no significant difference in changes in the Clinical Progression Scale between nafamostat with favipiravir and favipiravir alone groups (median, -0·444 vs. -0·150, respectively; least-squares mean difference, -0·294; p=0·364). Time to improvement in body temperature was significantly shorter in the combination group (5·0 days; 95% CI, 4·0-7·0) than in the favipiravir group (9·0 days; 95% CI, 7·0-18·0; p=0·009). Changes in SpOAlthough our study showed no differences in clinical progression, earlier defervescence and recovery of SpOThis study was registered in the Japan Registry of Clinical Trials (identifier: jRCTs031200026) and WHO's International Clinical Trial Registry Platform (identifier: JPRN-jRCTs031200026).