A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate

INTERVENTION: Product Name: Peramivir Product Code: BCX‐1812 Pharmaceutical Form: Solution for infusion INN or Proposed INN: Peramivir CAS Number: 330600‐85‐6 Current Sponsor code: BCX‐1812 Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 400‐ Pharmaceutical form of the placebo: Solution for infusion Route of administration of the placebo: Intravenous use CONDITION: Treatment of experimental influenza PRIMARY OUTCOME: Main Objective: To evaluate the virologic activity of peramivir by intravenous; administration compared to placebo against experimental; challenge with A/Panama/2007/99. Primary end point(s): The change (reduction) from baseline in influenza virus titer by; serial measurements of tissue culture infective dose (TCID50). Secondary Objective: To assess the safety and tolerability of peramivir 400 mg; administered intravenously once daily for five days to healthy; adults aged 18 to 49 years who are selected based on serologic; evidence of susceptibility to A/Panama/2007/99.; ; To assess the frequency and severity of influenza symptoms in; subjects receiving either peramivir or placebo following; experimental challenge with A/Panama/2007/99.; ; To assess the time to resolution of fever in subjects receiving; either peramivir or placebo following experimental challenge; with A/Panama/2007/99.; ; To assess the pharmacodynamic relationship between exposure; to peramivir (as measured by plasma drug concentrations) and; virological response. INCLUSION CRITERIA: A subject will be eligible for enrollment if all of the following apply: 1. Male or Female (non‐pregnant, non‐lactating), age 18 to 49 years, inclusive. 2. Comprehension of the study requirements; availability for the required study period, ability to attend scheduled study visits, and willingness to participate in the inpatient challenge. 3. Willingness to provide written consent for participation after reading the Consent Form and after having adequate opportunity to discuss the study with an Investigator or qualified deputy. 4. Good general health status as determined by a screening evaluation completed = 42 days prior to challenge. 5. For female subjects, provision of a history of reliable contraceptive practices (hysterectomy or bilateral tubal ligation, oral or implanted contraceptive use, intrauterine device, barrier method plus spermicide, history of a single male partner with vasectomy, or a hist