Participants will receive continued standard of care (SOC) therapy together with RDV 200 mg on Day 1 followed by RDV 100 mg on Days 2, 3, 4, and 5.

Participants will receive continued standard of care therapy together with RDV 200 mg on Day 1 followed by RDV 100 mg on Days 2, 3, 4, 5, 6, 7, 8, 9, and 10.

Participants will receive continued standard of care therapy.

Participants will receive continued standard of care therapy together with RDV 200 mg on Day 1 followed by RDV 100 mg on Days 2, 3, 4, 5, 6, 7, 8, 9, and 10.

Administered as an intravenous infusion

Clinical status was derived from death, hospital discharge, and ordinal scale as follows: score of "1" was used for all days on or after the date of death; score of "7" was used for all days on or after discharged alive date; last available assessment for missing value. The scale is as follows: 1. Death; 2. Hospitalized, on invasive mechanical ventilation or Extracorporeal Membrane Oxygenation (ECMO); 3. Hospitalized, on non-invasive ventilation or high flow oxygen devices; 4. Hospitalized, requiring low flow supplemental oxygen; 5. Hospitalized, not requiring supplemental oxygen - requiring ongoing medical care (coronavirus (COVID-19) related or otherwise); 6. Hospitalized, not requiring supplemental oxygen - no longer required ongoing medical care (other than per protocol remdesivir administration; 7. Not hospitalized. The odds ratio represents the odds of improvement in the ordinal scale for a RDV group relative to the SOC group.

TEAEs were defined as the following: any AE with an onset date on or after the study treatment start date and no later than 30 days after permanent discontinuation of study treatment and/or any AE leading to premature discontinuation of study treatment. For participants randomized to the SOC group, all AEs reported on or after the protocol-specified Day 1 visit were considered as treatment emergent.