Inclusion Criteria:

1. Positive SARS-CoV-2 test conducted ≤ 5 days prior to randomization
2. Mild or moderate COVID-19 with symptom onset ≤ 5 days before randomization and at least one COVID-19 related symptom present at time of screening
3. Subject must be high risk, defined below:

1. Age ≥70 years OR
2. Age ≥55 years with one of the following: i) obesity (body mass index [BMI] ≥30 kg/m2) ii) diabetes mellitus iii) cardiovascular disease or hypertension iv) chronic lung disease requiring routine therapy OR
3. Age 50 to 54 years with two of the following: i) obesity (BMI ≥30 kg/m2) ii) diabetes mellitus iii) cardiovascular disease or hypertension iv) chronic lung disease requiring routine therapy OR
4. Age ≥18 years with one of the following: i) Down syndrome, sickle cell disease, dementia, Parkinson's disease, or care home residents ii) One of the following immunocompromising conditions or immunosuppressive treatments: receiving chemotherapy for cancer, hematologic malignancy, being within 2 years of a hematopoietic stem cell transplant, receipt of a solid organ transplant and on immunosuppressive therapy, human immunodeficiency virus (HIV) infection untreated or with CD4+ T lymphocyte count <350 cells per cubic millimeter, moderate/severe primary immunodeficiency, taking immunosuppressive medications
5. Use of adequate contraception for females of childbearing potential

Exclusion Criteria:

1. Severe or critical COVID-19 illness
2. Admitted to a hospital within 90 days prior to randomization due to COVID-19
3. Use of other investigational drugs within 30 days prior to planned dosing, or plans to enroll in another clinical trial of an investigational agent while participating in the present study
4. Initiation or planned initiation of remdesivir for treatment of the current SARS-CoV-2 infection
5. Requirement of prohibited medications, including hydroxychloroquine or amiodarone within 3 months prior to screening. Note: Subjects who had already initiated any COVID-19 drug with antiviral effects intended to treat symptomatic SARS-CoV-2 infection (≥ 24 hours prior to randomization) will be excluded. During screening (or within 24 hours prior to or after randomization), locally available COVID-19 drugs with antiviral effects (including but not limited to nirmatrelvir/ritonavir, molnupiravir, favipiravir, monoclonal antibodies) will be permitted.
6. Other known active viral or bacterial infection at the time of screening, such as influenza and respiratory syncytial virus (RSV). Note: This exclusion does not apply to subjects with stable chronic viral infections, such as chronic hepatitis C virus (HCV) or HIV providing other eligibility criteria are met.
7. Receiving dialysis or have known severe renal impairment
8. History of severe hepatic impairment (Child-Pugh Class C)
9. Known allergy or hypersensitivity to components of study drug