A Study of Intravenous Zanamivir Versus Oral Oseltamivir in Adults and Adolescents Hospitalized With Influenza

The recent influenza pandemic has highlighted the need for alternative formulations for anti-influenza therapies. This will be an international Phase III, double-blind, double-dummy, 3-arm study to evaluate the efficacy, antiviral activity and safety of IV zanamivir 600 mg twice daily compared to oral oseltamivir 75 mg twice daily, and 600 mg IV zanamivir twice daily compared to 300 mg IV zanamivir for 5 days in hospitalized subjects with laboratory confirmed or suspected influenza infection. For a given subject, the initial 5-day treatment course may be extended for up to 5 additional days if clinical symptoms or patient characteristics as assessed by the investigator warrant further treatment. Alternatively, if the investigator considers that a subject is failing to improve clinically on their randomized treatment, the investigator can choose to initiate the switch/rescue option (600 mg IV zanamivir twice daily) on any day from Day 6 through Day 10 for up to an additional 5 days of treatment. On switching treatments, subjects complete a maximum of 14 days of treatment and are followed-up to Post-Treatment +28 Days.