Table 3.
Virologic Outcomes in the Intention-to-Treat, Influenza-Infected Population
| Outcome | US316 | US317 | ||
|---|---|---|---|---|
| Placebo | Favipiravir | Placebo | Favipiravir | |
| Time to cessation of detecting infectious virus, h, median (95% CI) | 70.7 (68.1–71.5) (n = 322) |
47.5 (46.8–47.9) (n = 301) |
71.7 (68.3–72.1) (n = 169) |
47.7 (47.4–47.8) (n = 526) |
| Viral titer change baseline to day 2, log10 TCID50/mL, mean (SD) | −0.8 (1.7) (n = 314) |
−1.3 (1.7) (n = 293) |
−1.1 (1.7) (n = 161) |
−1.7 (1.7) (n = 505) |
| Viral titer change baseline to day 3, log10 TCID50/mL, mean (SD) | −1.6 (2.0) (n = 311) |
−2.1 (1.7) (n = 291) |
−1.9 (2.0) (n = 162) |
−2.6 (1.9) (n = 504) |
| Viral titer AUC for days 1–5, TCID50 × h/mL, mean (SD) | 143.8 (89.0) (n = 318) |
104.1 (64.6) (n = 296) |
152.5 (101.6) (n = 165) |
115.5 (65.9) (n = 509) |
| Viral RNA load AUC, qRT-PCR particles × h/mL, mean (SD) | 506.5 (130.9) (n = 311) |
475.8 (127.0) (n = 290) |
493.1 (138.0) (n = 162) |
456.8 (126.4) (n = 490) |
| Time to undetectable viral RNA, h, median (95% CI) | 98.2 (96.6 to >120) (n = 322) |
100.1 (98.5 to >120) (n = 301) |
>120 (97.4 to >120) (n = 169) |
96.8 (96.4–101.6) (n = 526) |
The ITTI population comprised participants with RT‐PCR–confirmed influenza virus infection. In US316, the observed baseline mean (SD) viral titers on day 1 were 3.0 (1.8) and 2.8 (1.7) log10 TCID50/mL in the placebo and favipiravir groups, respectively, and the mean (SD) log10 viral particles/mL were 6.8 (1.8) and 6.9 (1.5), respectively.
AUC was calculated using the trapezoidal method. Subjects missing a baseline or follow‐up value were not included in the AUC analyses. Time‐to‐event analyses were assessed by using Kaplan–Meier estimates, while the between‐group comparisons were assessed by using a 2–sided Peto–Peto–Prentice test. The lower limit of quantification was defined as <2.18 viral particles/mL in influenza type A and <2.93 viral particles/mL in influenza type B.
Abbreviations: AUC, area under the concentration‐time curve; CI, confidence interval; qRT‐PCR, qualitative reverse-transcription polymerase chain reaction; SD, standard deviation; TCID50, median tissue culture infectious dose.