A Study to Evaluate EDP 938 Regimens in Children With RSV

Inclusion Criteria:

• Male or female who is either ≥6 months to ≤36 months (for Age Group 1) or ≥28 daysto <6 months (for Age Group 2), defined at the time of randomization. Subjects inAge Group 2 must have been born ≥29 weeks of gestation to be eligible.

• Subjects diagnosed with RSV infection

• Subjects with signs of an acute respiratory illness with onset ≤7 days for Part 1and ≤5 days for Part 2 before the time of signing the ICF

• In the Investigator's opinion, the subject's caregiver understands and is able tocomply with protocol requirements, instructions, and protocol-stated restrictions,and the subject is likely to complete the study as planned

Exclusion Criteria:

• Use of or anticipated need for invasive mechanical ventilation, cardiopulmonarybypass, hemodialysis, or extracorporeal membrane oxygenation; or subjects who arenot expected to survive the current illness

• Underlying immune deficiency, (e.g., from confirmed human immunodeficiency virusinfection or use of an immunosuppressive medication except immunoglobulin Adeficiency)

• Receipt of (within 12 months before Screening) or on a waiting list for a bonemarrow, stem cell, or solid organ transplant, or who received radiation orchemotherapy (within 12 months before screening)

• Receiving chronic oxygen therapy at home before admission

• Subjects whose mother received an investigational RSV vaccination while pregnantwith the subject if they were born at term (≥37 weeks of gestation) and are lessthan 12 months of age

• In Part 2, subjects dosed with an investigational or approved medication that isintended to prevent or treat RSV infection within the following times before thefirst dose of study drug: ribavirin 35 days; palivizumab 100 days; nirsevimab 350days; other RSV-specific monoclonal antibody 5 half-lives of the specific antibody;RSV vaccines 12 months.