Inclusion Criteria:

• Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) positive as determined by Polymerase Chain Reaction (PCR) or other commercially available or public health assay (e.g., Nucleic Acid Amplification Test [NAAT] and antigen tests) in any respiratory specimen.
• Hospitalized for COVID-19.
• Age ≥ 12 years and weighing at least 40 kg.
• Oxygen (O2) saturation ≤ 94% on room air or requiring O2 supplement or Radiographic evidence of pulmonary infiltrates for COVID-19.
• Severely reduced kidney function (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73m^2 ), using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and revised Schwartz equations for adults and adolescents, respectively, including people with ESKD requiring chronic dialysis but not people requiring RRT for AKI.
• Willing and able to provide written informed consent, or with a legal representative who can provide informed consent, or enrolled under ICH E6(R2) 4.8.15 emergency use provisions as deemed necessary by the investigator (age ≥ 18) prior to performing study procedures.
• The interval between COVID-19 symptoms onset and randomization is no more than 10 days.
• Male participants and female participants of childbearing potential who engage in heterosexual intercourse must agree to use protocol-specified method(s) of contraception.

Exclusion Criteria:

• Received any investigational drug, RDV, or other antiviral treatment for COVID-19.
• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 5 times the upper limit of normal.
• Invasive mechanical ventilation, noninvasive mechanical ventilation, ECMO, or RRT for acute kidney injury (AKI).
• Positive serum pregnancy test at screening for women of childbearing potential or currently breastfeeding.
• Known hypersensitivity to the study drug, metabolites, or formulation sulfobutylether-beta-cyclodextrin (SBECD).