Protocol Number: IRC-005 A Randomized Double-Blind, Phase 3 Study Comparing the Efficacy and Safety of High-Titer versus Low-Titer Anti-Influenza Immune Plasma for the Treatment of Severe Influenza A

Study Design: This randomized, double-blinded, multicenter phase 3 trial will assess the efficacy and safety of anti-influenza immune plasma [also referred as “antiinfluenza plasma”] as an addition to standard of care antivirals in subjects hospitalized with severe influenza A infection (as defined in the inclusion criteria). Up to 40 sites in the United States will participate in this protocol. Adults and children may participate. There is no exclusion for pregnancy. A total of 150 eligible subjects will be randomized in a 2:1 ratio to receive either high-titer anti-influenza plasma or control (low-titer) plasma. All subjects will receive standard care antivirals. Randomization will be stratified by: • severity: in the intensive care unit (ICU), non-ICU hospitalization requiring supplemental oxygen, or non-ICU hospitalization not requiring supplemental oxygen. • age category (child/adult) Subjects will be assessed on Day 0 (baseline) and on Days 1, 2, 3, 7, 14, and 28. For participants who are not hospitalized on Days 2, 14, and 28, contact with the participant for the purpose of study data collection on those days may be performed by telephone. All subjects will undergo a series of efficacy, safety, and hemagglutination inhibition (HAI) assessments during the study. Blood samples will be collected on Day 0, 1, 3, and 7. Oropharyngeal (OP) swabs for influenza PCR will be obtained on Days 0 and 3. Study Agent: All plasma is from male donors to minimize the risk of transfusion-related acute lung injury (TRALI). The high-titer arm will receive 2 units of human plasma (FFP or FP24, 250-350 mL per unit, or pediatric equivalent) with influenza A/H1N1 and A/H3N2 HAI titers of at least 1:80.