['respiratory syncytial virus infection']
['presatovir', 'presatovir placebo']

        Key Inclusion Criteria:

          -  Current inpatient

          -  New onset of acute respiratory infectious symptoms, or acute worsening of chronic
             symptoms related to ongoing respiratory disease for ≤ 5 days prior to screening:

               -  Upper respiratory tract symptoms: nasal congestion, runny nose, sore throat, or
                  earache

               -  Lower respiratory tract symptoms: cough, sputum production, wheezing, dyspnea, or
                  chest tightness

          -  Documented to be RSV-positive at the current admission within 72 hours of screening,
             or as evaluated at screening

        Key Exclusion Criteria:

          -  Related to concomitant or previous medication use:

               -  Use of oral prednisone or other corticosteroid equivalent to:

                    -  > 20 mg/day for > 14 days prior to screening is not permitted.

                    -  > 20 mg/day for ≤ 14 days, including corticosteroids received during current
                       hospitalization (ie, bolus doses), is permitted.

                    -  ≤ 20 mg/day, regardless of duration, is permitted.

               -  Individuals taking a moderate or strong cytochrome P450 enzyme (CYP) inducer
                  including but not limited to rifampin, St John's Wort, carbamazepine, phenytoin,
                  efavirenz, bosentan, etracirine, modafinil, and nafcillin within 2 weeks prior to
                  the first dose of study drug

          -  Related to medical history:

               -  Pregnant, breastfeeding, or lactating females

               -  Individuals requiring > 50% supplemental oxygen (while the individual is awake)
                  at screening

               -  Individuals with a Clinical Frailty Scale (CFS) > 7 at Baseline

               -  Known significant abnormality altering the anatomy of the nose or nasopharynx
                  that in, the opinion of the investigator, will preclude obtaining adequate nasal
                  swab sampling in either nasal passage

               -  Waiting for or recently (within the past 12 months) received a bone marrow, stem
                  cell, or solid organ transplant, or who have received radiation or chemotherapy
                  within 12 months prior to Screening

               -  Individuals with HIV/AIDS and a known CD4 count < 200 cells/uL

               -  History of severe dementia or Alzheimer's disease

               -  History of drug and/or alcohol abuse that, in the opinion of the investigator,
                  may prevent adherence to study activities

          -  Related to medical condition at screening:

               -  Influenza-positive as determined by local diagnostic test

               -  Known Middle East Respiratory Syndrome coronavirus (MERS-CoV) infection or known
                  coinfection with other coronavirus

               -  Use of mechanical ventilation during the current admission, not including
                  noninvasive ventilation

               -  Clinically significant bacteremia or fungemia that has not been adequately
                  treated prior to Screening, as determined by the investigator

               -  Inadequate treatment of confirmed bacterial, fungal, or non-RSV pneumonia, as
                  determined by the investigator

               -  Excessive nausea/vomiting at admission, as determined by the investigator, that
                  precludes administration of an orally administered study drug

          -  Related to allergies:

               -  Known allergy to components of the study drug (microcrystalline cellulose,
                  mannitol, croscarmellose sodium, magnesium stearate, polyvinyl alcohol, titanium
                  dioxide, polyethylene glycol and talc)

               -  Documented history of acute (anaphylaxis) or delayed (Stevens-Johnson syndrome or
                  epidermal necrolysis) allergy to sulfa drugs

        Note: Other protocol defined Inclusion/Exclusion criteria may apply.
      