Study to Evaluate the Safety and Antiviral Activity of Remdesivir (GS-5734™) in Participants With Moderate Coronavirus Disease (COVID-19) Compared to Standard of Care Treatment

Key Inclusion Criteria:

   - Willing and able to provide written informed consent prior to performing study
   procedures (participants ≥ 18 years of age) or assent (participants ≥ 12 and < 18
   years of age) prior to performing study procedures. For participants ≥ 12 and < 18
   years of age, a parent or legal guardian willing and able to provide written informed
   consent prior to performing study procedures

   - Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 infection confirmed by
   polymerase chain reaction (PCR) test ≤ 4 days before randomization

   - Currently hospitalized and requiring medical care for COVID-19

   - Peripheral capillary oxygen saturation (SpO2) > 94% on room air at screening

   - Radiographic evidence of pulmonary infiltrates

Key Exclusion Criteria:

   - Participation in any other clinical trial of an experimental treatment for COVID-19

   - Concurrent treatment or planned concurrent treatment with other agents with actual or
   possible direct acting antiviral activity against SARS-CoV-2

   - Requiring mechanical ventilation at screening

   - Alanine Aminotransferase (ALT) or aspartate aminotransferase (AST) > 5 X upper limit
   of normal (ULN)

   - Creatinine clearance < 50 mL/min using the Cockcroft-Gault formula for participants ≥
   18 years of age {Cockcroft 1976} and Schwartz Formula for participants < 18 years of
   age

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