Favipiravir reduced median time to illness alleviation vs placebo in one trial (84.2 vs 98.6 hours; P=.004) but did not significantly reduce time to alleviation in a second trial.
RCT (n=1,318)
Double-blind
1:1 in US316; 3:1 in US317
Does favipiravir reduce time to illness alleviation in otherwise healthy adults with uncomplicated influenza?
Favipiravir demonstrated significant antiviral efficacy but inconsistent clinical illness alleviation in uncomplicated influenza.
Effect estimate: 14.4-hour reduction
Absolute Event Rate: 84.2% vs 98.6%
p-value: p=.004
BACKGROUND: We conducted double-blind, placebo-controlled trials assessing the efficacy and tolerability of favipiravir in acute influenza. METHODS: Otherwise healthy adults with influenza-like symptoms and fever of ≤48 hours were randomized to favipiravir (1800 mg twice daily BID on day 1, 800 mg BID on days 2-5) or placebo tablets (1:1 in US316; 3:1 in US317). The primary efficacy endpoint was the time to illness alleviation when 6 influenza symptoms were self-rated as absent or mild and fever was absent in the intention-to-treat, influenza-infected participants. RESULTS: In US316 (301 favipiravir, 322 placebo), favipiravir was associated with a 14.4-hour reduction (median, 84.2 vs 98.6 hours; P = .004) in time to illness alleviation vs placebo. In US317 (526 favipiravir, 169 placebo), favipiravir did not significantly reduce time to alleviation (median, 77.8 vs 83.9 hours). In both trials favipiravir was associated with reduced viral titers, RNA load area under the curve over days 1-5, and median times to cessation of virus detection (P < .001). Aside from asymptomatic hyperuricemia, no important differences in adverse events were found. CONCLUSIONS: This favipiravir dosing regimen demonstrated significant antiviral efficacy but inconsistent illness alleviation in uncomplicated influenza. Studies of higher doses and antiviral combinations for treating serious influenza and other RNA viral infections are warranted. Clinical Trials Registration. NCT02026349; NCT02008344.
Hayden et al. (Thu,) conducted a rct in Uncomplicated influenza (n=1,318). Favipiravir vs. Placebo was evaluated on Time to illness alleviation when 6 influenza symptoms were self-rated as absent or mild and fever was absent (14.4-hour reduction, p=.004). Favipiravir reduced median time to illness alleviation vs placebo in one trial (84.2 vs 98.6 hours; P=.004) but did not significantly reduce time to alleviation in a second trial.