A Study of EDP-938 in Non-hospitalized Adults With RSV Who Are at High Risk for Complications.

Inclusion Criteria: * At least one of the following conditions that predispose them to complications after RSV infection: 1. Age ≥65 years 2. Congestive heart failure (CHF) 3. Asthma 4. Chronic obstructive pulmonary disease (COPD) * The subject has a new onset of any of the following symptom(s) or worsening of pre-existing symptom(s) consistent with a respiratory tract infection no more than 72 hours prior to the administration of the first dose of study drug: feeling feverish, headache, neck pain, fatigue, loss of appetite, interrupted sleep, body aches, sore throat, nasal congestion, cough, cough with phlegm, wheezing, or short of breath. * The subject reports at least 2 of the following symptoms, one of which must be reported as at least 'moderate' severity: cough, cough with phlegm, wheezing, or short of breath * The subject has tested positive for RSV infection using a NAAT (polymerase chain reaction \[PCR\] or other) on a nasal/nasopharyngeal swab sample. * A woman of childbearing potential who is sexually active with a male must agree to use two effective methods of contraception from the date of Screening until 30 days after her last dose of study drug. * A male subject who has not had a vasectomy and is sexually active with a woman of childbearing potential must agree to use effective contraception from the date of Screening to 90 days after his last dose of study drug. Exclusion Criteria: * The subject has an anticipated need for hospitalization within 24 hours of signing the Study ICF * The subject receives systemic antiviral, antibacterial, antifungal, or antimycobacterial therapy within 7 days prior to signing the Study ICF * The subject has concomitant respiratory infections that are viral (other than RSV but including influenza), bacterial, or fungal, including systemic bacterial or fungal infections, within 7 days prior to signing the Study ICF * The subject has a SARS-CoV-2 test result that is positive within 28 days prior to signing the Study ICF * The subject has COPD with spirometry results (obtained within 1 year prior to signing the Study ICF) FEV1 ≤35% * The subject has a known positive human immunodeficiency virus infection, active hepatitis A virus infection, chronic hepatitis B virus infection, and/or current hepatitis C virus (HCV) infection; subjects with a history of HCV infection who have achieved a documented sustained virologic response 12 weeks after completion of HCV therapy may be enrolled. * The subject has any of the following cardiac conditions: any congenital heart disease, congenital long QT syndrome, or any clinical manifestation resulting in QT interval prolongation * The subject has immunocompromised status * The subject is living in institutional care or assisted living facility and is also receiving acute care management for any respiratory condition; Note: Independent living apartments are not considered institutional care or assisted living facility