Efficacy and Safety Study of Laninamivir Octanoate TwinCaps® Dry Powder Inhaler in Adults With Influenza

Approximately 636 subjects will be randomized into the Study. Following confirmation of circulating influenza in the local area, eligible subjects with recent onset of symptomatic presumptive influenza A or B infection will be enrolled in the study. Subjects must be randomized within 40 hours of the first symptom onset. Subjects will be randomized to placebo, 40 or 80 mg of laninamivir octanoate. The study will be conducted on an outpatient basis. The first dose of study drug will be administered via inhalation within 4 hours of randomization in the clinic, followed by a second dose at home. Participants will be followed for 14 days to assess efficacy, virology and safety. Outpatient visits to the investigational site are scheduled on Days 2 (optional PK Sub-study Visit) 3, 5, 8, 15. An End of study visit will be performed on Day 29.