Favipiravir treatment does not influence disease progression among adult patients hospitalized with moderate-to-severe COVID-19: a prospective, sequential cohort study from Hungary.

Data suggests that favipiravir (FVP) could be used against SARS-CoV-2. Our aim was to investigate the role of FVP in COVID-19 treatment. A prospective sequential cohort study was performed among adults hospitalized at our center between March and August 2020 with moderate-to-severe, PCR-confirmed COVID-19. For diagnosis and severity, ECDC and WHO definitions were utilized. Patients were screened for inclusion by a priori criteria and included in the FVP cohort if standard-of-care (SOC) + FVP or the non-FVP cohort if SOC ± other antivirals without FVP were administered for > 48 h from diagnosis. Treatment allocation was done per national guidelines, based on severity and drug availability. Primary endpoint was disease progression, a composite of 14-day all-cause death, need for mechanical ventilation, or immunomodulatory therapy. The impact of FVP exposure on disease progression was analyzed by binomial logistic regression. In all, 150 patients were included, 75 in each cohort. Disease progression (17/75, 22.7% vs. 10/75, 13.3%, p = 0.13), 14-day all-cause death (9/75, 12.0% vs. 10/75, 13.3%, p = 0.8), and need for mechanical ventilation (8/75, 10.7% vs. 4/75, 5.3%, p = 0.22) were similar, while immunomodulatory therapies were required more frequently among patients receiving FVP (10/75, 13.3% vs. 1/75, 1.3%, p < 0.01). The use of favipiravir was not retained as a protective factor against disease progression in multivatiate analysis. Time to antiviral therapy from PCR positivity, disease severity, need for oxygen supportation, and ICU admittance rates did not differ statistically between cohorts. In this study, favipiravir did not seem to positively affect disease progression.