Conditions: Influenza, Human
Keywords: Seasonal Influenza Pandemic Orthomyxoviridae Infections Influenza Influenza A Virus, H1N1 Subtype Enzyme Inhibitors Influenza, seasonal Respiratory Tract Diseases Zanamivir Pharmacologic Actions Antiviral Agents Anti-Infective Agents H1N1 Neuraminidase inhibitor Influenza B virus
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 626
Healthy volunteers: no

Brief summary:
The purpose of this study is to test the safety and efficacy of zanamivir given intravenously and how well it works at two different doses in hospitalized adolescents and adults with flu. Zanamivir will be compared with oseltamivir, which is used for treating flu.

Detailed description:
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.

Arms:
arm 1: 300mg of IV zanamivir infusion twice daily plus oral oseltamivir placebo twice daily arm 2: 600mg of IV zanamivir infusion twice daily plus oral oseltamivir placebo twice daily arm 3: 75mg oral oseltamivir twice daily plus intravenous placebo zanamivir twice daily

Interventions: intervention 1: Zanamivir intervention 2: Placebo to match zanamivir intervention 3: Oseltamivir intervention 4: Placebo to match oseltamivir
Intervention descriptions: intervention 1: Zanamivir aqueous solution, 10 mg/mL, will be provided as a single use, sterile clear, colorless preparation in 20 mL clear glass vials. intervention 2: Placebo to match IV zanamivir will be provided as a normal saline solution of a matched volume. intervention 3: Oseltamivir will be provided as over-encapsulated 75 mg capsules. intervention 4: Placebo to match oral oseltamivir will be provided as capsules with a common excipient of appropriate quality.

Protocol document: