Beijing Institute of Pharmacology and Toxicology

Title: An adaptive study of the pharmacokinetics of favipiravir in patients with severe influenza Study Design: An open label, single group assignment, adaptive study to evaluate the pharmacokinetics of favipiravir in adult patients with severe influenza.
In the first stage, participants will receive favipiravir 1600mg BID on day 1, followed by favipiravir 600mg BID for 9 days.
If the proportion of patients with a minimum observed plasma trough concentration above the MEC (20μg/ml) at all measured time points after the second dose is less than 80% then a second patient cohort will be recruited and will receive favipiravir 1800mg BID on day 1, followed by favipiravir 800mg BID for 9 days.
Intervention: The 1st stage: 1600mg BID on day 1, followed with 600mg BID for 9 days. Sample size: 15 The 2nd stage: 1800mg BID on day 1, followed with 800mg BID for 9 days. Sample size: 15 Population: Males and females aged 18 years or older admitted to hospital with a positive PCR test for influenza and a PaO2/FiO2≤300mmHg or/and on mechanical ventilation for severe lung infection on admission.
Sample size 15 or 30 severe influenza patients Research hypothesis The administration of oral favipiravir at either 1600mg/600mg BID or 1800/800mg BID will result in ≥ 80% patients achieving a minimum observed plasma trough concentration above the MEC (20μg/ml) at all measured time points after the second dose.
Phase: Phase 2a, PK, safety and feasibility study. Description of Study Agent: Favipiravir (T-705) a viral RNA-dependent RNA polymerase inhibitor.
Study Duration: 1 year Participant Duration: 38 days

The purpose of this study is to explore the therapeutic efficacy of Favipiravir, a broad-spectrum antiviral drug against severe cases of Ebola Virus Disease (EVD), which is the most difficult aspect for clinical management of EVD due to its high fatality rate.