Due to preliminary efficacy results from an influenza challenge trial

The purpose of this study is to evaluate the rate of decline in quantitative viral load measured in hospitalized patients with Influenza A infection

This is a randomized, placebo-controlled, double-blind phase IIa proof-of-concept study, designed to evaluate the effect of CR8020, CR6261, or placebo in hospitalized patients with influenza A infection that are receiving standard of care. Up to 262 participants will be randomized to receive 30 mg/kg of CR8020, 30 mg/kg of CR6261, or placebo. The study duration will be approximately 117 days for each participant. Prior to enrollment, participants will be screened to assess their eligibility. Eligible participants will be randomized to CR8020, CR6261, or placebo and study drug will be administered on Day 1. Participants will be followed up for 115 days in 9 visits on Days 2 to 8, Day 29, and Day 116 (end of study). After hospital discharge, the remaining follow-up visits will be performed as outpatient visits.

Inclusion Criteria:

Participant requires hospitalization/ Each participant or his or her legally acceptable representative must sign an informed consent form/ Participant must be able to start the infusion within 36 hours from the time the screening specimen was collected/ A woman must either be not of childbearing potential or of childbearing potential and agrees to practice two forms of highly effective method of birth control/ A woman of childbearing potential must have a negative serum (beta human chorionic gonadotropin [beta hCG]) at screening/ A man who is sexually active with a woman of childbearing potential and has not had a vasectomy must agree to use a barrier method of birth control/

Exclusion Criteria:

Participant is a female who is pregnant or breastfeeding/ Participant undergoing peritoneal dialysis, hemodialysis or hemofiltration/ Participant has presence of any pre-existing illness that, in the opinion of the investigator, would place the participant at an unreasonably increased risk through participation in this study/ Participant has prior treatment with an experimental mAb; or receipt of IgG within 3 months or on chronic mAb treatment prior to enrollment/ Participant has known or suspected hypersensitivity to any of the CR8020 or CR6261 excipients (sucrose, L-histidine L-histidine monohydrochloride, polysorbate 20)/ Participant received an investigational product (including investigational vaccines) or used an investigational medical device within 60 days before the planned start of treatment, is currently enrolled in an interventional investigational study, or is an employee of the investigational site/