Inclusion Criteria:

1. Ability to understand the purpose and risks of the study and provide signed and dated
informed consent or have a legal representative provide consent and authorization to
use protected health information (in accordance with national and local patient
privacy regulations)

2. Men and women ≥18 years of age at the time of signing the informed consent form

3. Confirmed infection with SARS-CoV-2 confirmed per World Health Organization (WHO)
criteria (including positive RT-PCR nucleic acid test of any specimen [eg,
respiratory, blood, urine, stool, or other bodily fluid]) within 4 days of
randomization

4. COVID-19 pneumonia (documented radiographically) requiring hospitalization and oxygen
saturation <94% on room air or requires supplemental oxygen

5. Able to swallow pills

6. Willing to follow contraception guidelines

Exclusion Criteria:

1. Respiratory failure at time of screening due to COVID-19

2. Known medical resuscitation within 14 days of randomization

3. Pregnant or breast feeding

4. Suspected uncontrolled active bacterial, fungal, viral, or other infection (besides
infection with SARS-CoV-2)

5. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and/or bilirubin ≥ 3x
upper limit of normal (ULN) and/or severe hepatic impairment detected within 24 hours
at screening (per local lab)

6. Uncontrolled or untreated symptomatic arrhythmias, myocardial infarction within the
last 6 weeks, or congestive heart failure (NYHA Grade 3 or 4). Exception: Subjects
with controlled, asymptomatic atrial fibrillation during screening are allowed to
enroll

7. Treatment with a strong cytochrome P450 (CYP)3A inhibitor (within 14 days before first
dose of study drug) or inducer (within 7 days before first dose of study drug).

8. Requires treatment with proton-pump inhibitors (PPIs; eg, omeprazole, esomeprazole,
lansoprazole, dexlansoprazole, rabeprazole, or pantoprazole). Subjects receiving PPIs
who switch to H2-receptor antagonists or antacids are eligible for enrollment in this
study

9. Received oral antirejection or immunomodulatory drugs (eg, anticytokines, Btk
inhibitors, JAK inhibitors, PI3K inhibitors) within 30 days before randomization on
study