Efficacy and Safety of Favipiravir and Ribavirin Formulation for Treatment of COVID-19

The clinical picture of COVID-19 disease is in a broad spectrum, which includes asymptomatic infection, a mild upper respiratory tract infection, respiratory failure, and even severe viral pneumonia with death. The alarming levels of spread and severity of COVID-19 caused a global emergency and this outbreak has been characterized as a pandemic by the World Health Organization (WHO). Coronavirus entry into host cells is an important determinant of viral infectivity and pathogenesis. SARS-CoV S1 contains a receptor-binding domain (RBD) that specifically recognizes angiotensin-converting enzyme 2 (ACE2) as its receptor. SARS-CoV spike needs to be proteolytically activated at the S1/S2 boundary, such that S1 dissociates and S2 undergoes a dramatic structural change. These SARS-CoV entry-activating proteases include cell surface protease TMPRSS2 and lysosomal proteases cathepsins. These features of SARS-CoV entry contribute to its rapid spread and severe symptoms and high fatality rates of infected patients. Ribavirin is a guanosine analog that interferes with the replication of RNA and DNA viruses. Ribavirin was used during the Severe Acute Respiratory Syndrome (SARS) outbreak in combination with corticosteroids, which have an anti-inflammatory effect. Favipiravir is a substrate for viral RNA-dependent RNA polymerase (RdRp) and showed anti-influenza virus activity. Favipiravir is effective against other RNA viruses, poliovirus, rhinovirus, and respiratory syncytial virus and evaluated and developed as a broad spectrum anti-RNA virus drug, including lethal RNA virus infections. According to national guidelines, Favipiravir treatment is applied to COVID-19 infection in Turkey. The main purpose of this study is to obtain efficacy and safety data for ribavirin and favipiravir in the Turkish patient cohort diagnosed with COVID-19. This study designed as an open-label, multicenter, parallel-group, randomized, phase II/III clinical drug trial. This study will be conducted in 4 sites.