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

• Time to Resolution of Fever [ Time Frame: Up to 14 days ]
  The time to resolution of fever (defined as the number of hours from initiation of study drug until temperature is less than 37.2 degrees C [99.0 degrees F] and no antipyretic medications had been taken in the previous 12 hours) was estimated using the method of Kaplan-Meier. Differences between the treatment groups were assessed using the log rank statistic controlling for current smoking behavior. Subjects who did not have resolution of fever were censored at the time of the last assessment. No adjustment for multiple comparisons was performed.
• Time to Resumption of Ability to Perform Usual Activities [ Time Frame: Up to 14 days ]
  The time to resumption of a subject's self-assessed ability to perform his or her usual activities was estimated using the method of Kaplan-Meier. Differences between the treatment groups were assessed using the log rank statistic controlling for current smoking behavior. Subjects who were not able to resume performance of usual activities were censored at the time of the last assessment.
• Change From Baseline to Day 2 in Influenza Virus Titer [ Time Frame: Baseline and approximately 24 hours after treatment ]
  The change in viral titers was defined as the time-weighted change from baseline in log_10 tissue culture infective dose_50 (TCID_50/mL) and was summarized for each treatment group. The differences between the treatment groups were evaluated using a Wilcoxon Rank Sum Test controlling for current smoking behavior. Specimens for virologic culture and determination of influenza virus TCID_50/mL were obtained on Day 2 (approximately 24 hours after treatment), on Day 3 (approximately 48 hours after treatment), on Day 5 (approximately 96 hours after treatment), and on Day 9 (approximately 192 hours after treatment).
• Change From Baseline to Day 3 in Influenza Virus Titer [ Time Frame: Baseline and approximately 48 hours after treatment ]
  The change in viral titers was defined as the time-weighted change from baseline in log_10 tissue culture infective dose_50 (TCID_50/mL) and was summarized for each treatment group. The differences between the treatment groups were evaluated using a Wilcoxon Rank Sum Test controlling for current smoking behavior. Specimens for virologic culture and determination of influenza virus TCID_50/mL were obtained on Day 2 (approximately 24 hours after treatment), on Day 3 (approximately 48 hours after treatment), on Day 5 (approximately 96 hours after treatment), and on Day 9 (approximately 192 hours after treatment).
• Change From Baseline to Day 5 in Influenza Virus Titer [ Time Frame: Baseline and approximately 96 hours after treatment ]
  The change in viral titers was defined as the time-weighted change from baseline in log_10 tissue culture infective dose_50 (TCID_50/mL) and was summarized for each treatment group. The differences between the treatment groups were evaluated using a Wilcoxon Rank Sum Test controlling for current smoking behavior. Specimens for virologic culture and determination of influenza virus TCID_50/mL were obtained on Day 2 (approximately 24 hours after treatment), on Day 3 (approximately 48 hours after treatment), on Day 5 (approximately 96 hours after treatment), and on Day 9 (approximately 192 hours after treatment).
• Change From Baseline to Day 9 in Influenza Virus Titer [ Time Frame: Baseline and approximately 192 hours after treatment ]
  The change in viral titers was defined as the time-weighted change from baseline in log_10 tissue culture infective dose_50 (TCID_50/mL) and was summarized for each treatment group. The differences between the treatment groups were evaluated using a Wilcoxon Rank Sum Test controlling for current smoking behavior. Specimens for virologic culture and determination of influenza virus TCID_50/mL were obtained on Day 2 (approximately 24 hours after treatment), on Day 3 (approximately 48 hours after treatment), on Day 5 (approximately 96 hours after treatment), and on Day 9 (approximately 192 hours after treatment).

• Drug: Peramivir 150 mg
  Single dose administered as bilateral 2-mL intramuscular injections in each gluteal muscle (one injection of peramivir 150 mg and one injection of placebo).
  Other Name: BCX1812
• Drug: Peramivir 300 mg
  Single dose administered as bilateral 2-mL intramuscular injections in each gluteal muscle (2 injections of peramivir 150 mg).
  Other Name: BCX1812
• Drug: Placebo
  Single dose administered as bilateral 2-mL intramuscular injections in each gluteal muscle (2 injections of placebo).

• Experimental: Peramivir 150 mg
  Intervention: Drug: Peramivir 150 mg
• Experimental: Peramivir 300 mg
  Intervention: Drug: Peramivir 300 mg
• Placebo Comparator: Placebo
  Intervention: Drug: Placebo

Inclusion Criteria:

• Age ≥18 years
• Presence of fever at time of screening of ≥38.0 ºC (≥100.4 ºF) taken orally, or ≥38.5 ºC (≥101.2 ºF) taken rectally. However, this requirement is waived if the subject has a history of fever within the 24 hours prior to screening and has been administered antipyretic(s) in the 6 hours prior to screening.
• Presence of at least one respiratory symptom (cough, sore throat, or nasal symptoms) of any severity (mild, moderate, or severe)
• Presence of at least one constitutional symptom (headache, malaise, myalgia, sweats and/or chills, or fatigue) of any severity (mild, moderate, or severe)
• Onset of illness no more than 48 hours before presentation. Note: Time of onset of illness is defined as either (1) the time when the temperature (either oral or rectal) was first measured as elevated (at least one ºC of elevation-oral temperature), OR (2) the time when the subject experienced the presence of at least one respiratory symptom AND the presence of at least one constitutional symptom.
• Rapid Antigen Test (RAT) performed on an adequate specimen collected from an anterior nasal swab is positive. A negative initial RAT may be repeated within one hour of obtaining a negative result. A second negative RAT result will exclude the subject from evaluation for enrollment.

• Females of childbearing potential must report one of the following:

  • Be surgically sterile
  • Have been sexually abstinent 4 weeks prior to date of screening evaluation and be willing to remain abstinent through 4 weeks after study drug administration
  • Use oral contraceptives or other form of hormonal birth control including hormonal vaginal rings or transdermal patches and have been using these for 3 months prior through 4 weeks after study drug administration
  • Use an intra-uterine device (IUD), or adequate barrier contraception (or double-barrier method such as condom or diaphragm with spermicidal gel or foam) as birth control 4 weeks prior to date of screening evaluation through 4 weeks after study drug administration.

Exclusion Criteria:

• Women who are breast-feeding
• History of diagnosed chronic obstructive pulmonary disease or diagnosis of severe persistent asthma
• History of chronic renal impairment requiring hemodialysis or known or suspected to have moderate or severe renal impairment (actual or estimated creatinine clearance <50 mL/min)
• History of congestive heart failure requiring daily pharmacotherapy with symptoms consistent with New York Heart Association Class II, III, or IV within the past 12 months
• Immunocompromised status due to illness or previous organ transplant
• Current use of systemic immunosuppressive medications (except inhaled corticosteroids)
• Use of rimantadine, amantadine, zanamivir, or oseltamivir in the past 7 days
• Immunized against influenza with live attenuated virus vaccine (FluMist®) in the previous 21 days
• Clinical evidence of active bacterial infection at any body site requiring therapy with oral or systemic antibiotics
• Clinically significant signs of acute respiratory distress
• Clinically significant signs of acute cardiac disease
• Screening ECG which suggests acute ischemia or presence of medically significant dysrhythmia
• Presence of a chronic disease or illness(es) with either clinical or historical evidence of recent exacerbation of such disease(s) or illness(es) or lack of control of such disease(s) or illness(es)
• History of hepatitis B, hepatitis C, or human immunodeficiency virus infection
• History of alcohol abuse or drug addiction within 1 year prior to admission in the study
• Participation in a study of any investigational drug within the last 30 days
• Positive urine pregnancy test