For Part 1 (Randomized cohort): 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 COVID-19 infection confirmed per World Health Organization (WHO) criteria (including positive nucleic acid test of any specimen [eg, respiratory, blood, urine, stool, or other bodily fluid] within 3 weeks of study entry) with suspected pneumonia requiring hospitalization and oxygen saturation <94% on room air or requires 2-5 L/min of oxygen with at least one of the follow laboratory values: (a) Ferritin > 300 ng/mL for men and > 150 ng/mL for women (b) C-reactive protein (CRP) ≥ 10 mg/L (c) D-dimer > 1 mg/L (d) Absolute lymphocyte count < 1000 cells/µL 4. Able to swallow capsules or receive delivery of emptied capsule via a nasogastric (NG) or an enteral feeding tube 5. Willing to follow contraception guidelines For Part 2 Intensive Care Unit (ICU Cohort): 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 COVID-19 infection requiring ICU admission and requiring ≥ 6 L/min of oxygen or PaO2/FiO2 ≤300 mm Hg) 4. Able to swallow capsules or receive delivery of emptied capsule via a nasogastric (NG) or an enteral feeding tube 5. Willing to follow contraception guidelines

For Part 1 (Randomized cohort): 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 COVID-19 infection confirmed per World Health Organization (WHO) criteria (including positive nucleic acid test of any specimen [eg, respiratory, blood, urine, stool, or other bodily fluid] within 3 weeks of study entry) with suspected pneumonia requiring hospitalization and oxygen saturation <94% on room air or requires 2-5 L/min of oxygen with at least one of the follow laboratory values: (a) Ferritin > 300 ng/mL for men and > 150 ng/mL for women (b) C-reactive protein (CRP) ≥ 10 mg/L (c) D-dimer > 1 mg/L (d) Absolute lymphocyte count < 1000 cells/µL 4. Able to swallow capsules or receive delivery of emptied capsule via a nasogastric (NG) or an enteral feeding tube 5. Willing to follow contraception guidelines For Part 2 Intensive Care Unit (ICU Cohort): 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 COVID-19 infection requiring ICU admission and requiring ≥ 6 L/min of oxygen or PaO2/FiO2 ≤300 mm Hg) 4. Able to swallow capsules or receive delivery of emptied capsule via a nasogastric (NG) or an enteral feeding tube 5. Willing to follow contraception guidelines