Evaluation of the Efficacy and Safety of Peramivir in Subjects With Uncomplicated Acute Influenza.

Peramivir is a neuraminidase inhibitor that was previously shown to be effective in the treatment of human experimental influenza using an oral formulation. Parenteral formulations of peramivir (for intramuscular and intravenous injection) entered clinical development at the time of this Phase 2 study. A series of Phase 1 studies in human volunteers was completed that provided safety and pharmacokinetic results that supported the initiation of this Phase 2 multinational, randomized, double-mask study that compared the antiviral efficacy and safety of peramivir administered intramuscularly versus placebo in adults with uncomplicated acute influenza. Because of the unique pharmacokinetic and pharmacodynamic properties of peramivir - a long terminal half life in plasma and an extended duration of binding to the neuraminidase enzyme - subjects were randomized in a 1:1:1 ratio to receive a single dose of one of three treatments: peramivir 150 mg, peramivir 300 mg, and placebo. Study drug was administered as one 2-mL intramuscular injection in each gluteal muscle (total of 4 mL, injected in divided doses). This multinational study was originally to be conducted at approximately 80 sites in the US and Canada. When enrollment during the North American influenza season of 2006-2007 did not achieve the target, the study was extended to sites in Australia, New Zealand, South Africa, and Hong Kong.