Safety and Efficacy of Investigational Anti-Influenza Immune Plasma in Treating Influenza

Morbidity and mortality occur despite treatment with current antivirals. Circulating influenza H1N1 and H3N2 isolates are highly resistant to amantadine and rimantadine, whereas previous seasonal H1N1 isolates were highly resistant to oseltamivir. So there is concern that circulating influenza A/H1N1 2009 virus may also acquire oseltamivir resistance.

This randomized, open-label, multicenter phase 2 trial will assess the safety, efficacy, and pharmacokinetics (PK) of anti-influenza plasma in subjects with influenza. Hospitalized subjects with influenza at risk for severe disease (as defined in the inclusion criteria) will be eligible for study participation. This study will enroll adults, children and pregnant women.

Up to 40 sites in the United States will participate in this protocol. One hundred eligible subjects will be randomized in a 1:1 ratio to receive either 2 units (or pediatric equivalent) of anti-influenza immune plasma on Study Day 0 in addition to standard care or standard care alone (50 subjects receiving standard care alone; 50 subjects receiving anti-influenza immune plasma and standard care).

Subjects will be assessed on Study Day 0 (pre-dose), 30 minutes post-dose (plasma arm only), and on Study Days 1, 2, 4, 7, 14, and 28. All subjects will undergo a series of efficacy, safety, and PK (HAI) assessments during the study. Blood samples will be collected at each time point (except Day 1). Nasal and oropharyngeal swabs for influenza PCR will be obtained on Days 0,1,2,4 and 7.

Inclusion criteria

• Diagnosis of influenza A or B within 72 hours prior to enrollment (by local assay including rapid antigen, direct fluorescent antibody (DFA), polymerase chain reaction (PCR), or culture, and must be able to detect and distinguish influenza A from influenza B)
• Hospitalization for signs and symptoms of influenza (decision for hospitalization will be up to the individual treating clinician).
• Abnormal respiratory status, defined as room air saturation of oxygen (SaO2) less than 93% or tachypnea (respiratory rate above an age adjusted normal range)
• Agree to the storage of specimens and data
• ABO compatible plasma available on site or available within 24 hours after randomization with activity against locally circulating strains of influenza

Exclusion criteria

• Receipt of non-licensed treatment for influenza within the last 2 weeks (or plans to receive any time during the study). This does not include licensed drugs at non approved doses, off-label indications, or drugs available under an Emergency Use Authorization (EUA).
• History of severe allergic reaction to blood products (as judged by the investigator).
• Medical conditions for which receipt of 500 mL volume (or 8 mL/kg for pediatric patients) may be dangerous to the subject (e.g. decompensated congestive heart failure [CHF], etc.)
• Clinical suspicion that etiology of acute illness is primarily due to a condition other than active influenza virus replication (e.g., a bacterial or fungal infection)