* known cardio-pulmonary resuscitation within 14 days prior to randomization * pregnant or breast feeding * suspected uncontrolled active bacterial, fungal, viral, or other infection (besides infection with sars-cov-2) * alanine aminotransferase (alt) ≥ 3x upper limit of normal (uln) and total bilirubin \> 2x uln * qtcf prolongation \>480 milliseconds * 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 * treatment with a strong cytochrome p450 (cyp3a4 inhibitor (within 14 days before first dose of study drug) or inducer (within 7 days before first dose of study drug) * received anti-rejection or immunomodulatory drugs (eg, anti-cytokines, btk inhibitors, jak inhibitors, pi3k inhibitors) within 30 days before randomization on study * concurrent participation in another clinical trial involving therapeutic interventions (observational study participation is acceptable) * any condition that confounds the ability to interpret data from the study * relevant renal impairment (egfr \<60 ml/min) * any significant medical condition, laboratory abnormality or psychiatric illness that would interfere or prevent the subject from participating in the study

* known cardio-pulmonary resuscitation within 14 days prior to randomization * pregnant or breast feeding * suspected uncontrolled active bacterial, fungal, viral, or other infection (besides infection with sars-cov-2) * alanine aminotransferase (alt) ≥ 3x upper limit of normal (uln) and total bilirubin \> 2x uln * qtcf prolongation \>480 milliseconds * 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 * treatment with a strong cytochrome p450 (cyp3a4 inhibitor (within 14 days before first dose of study drug) or inducer (within 7 days before first dose of study drug) * received anti-rejection or immunomodulatory drugs (eg, anti-cytokines, btk inhibitors, jak inhibitors, pi3k inhibitors) within 30 days before randomization on study * concurrent participation in another clinical trial involving therapeutic interventions (observational study participation is acceptable) * any condition that confounds the ability to interpret data from the study * relevant renal impairment (egfr \<60 ml/min) * any significant medical condition, laboratory abnormality or psychiatric illness that would interfere or prevent the subject from participating in the study

- known cardio-pulmonary resuscitation within 14 days prior to randomization - pregnant or breast feeding - suspected uncontrolled active bacterial, fungal, viral, or other infection (besides infection with sars-cov-2) - alanine aminotransferase (alt) ≥ 3x upper limit of normal (uln) and total bilirubin > 2x uln - qtcf prolongation >480 milliseconds - 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 - treatment with a strong cytochrome p450 (cyp3a4 inhibitor (within 14 days before first dose of study drug) or inducer (within 7 days before first dose of study drug) - received anti-rejection or immunomodulatory drugs (eg, anti-cytokines, btk inhibitors, jak inhibitors, pi3k inhibitors) within 30 days before randomization on study - concurrent participation in another clinical trial involving therapeutic interventions (observational study participation is acceptable) - any condition that confounds the ability to interpret data from the study - relevant renal impairment (egfr <60 ml/min) - any significant medical condition, laboratory abnormality or psychiatric illness that would interfere or prevent the subject from participating in the study

- known cardio-pulmonary resuscitation within 14 days prior to randomization - pregnant or breast feeding - suspected uncontrolled active bacterial, fungal, viral, or other infection (besides infection with sars-cov-2) - alanine aminotransferase (alt) ≥ 3x upper limit of normal (uln) and total bilirubin > 2x uln - qtcf prolongation >480 milliseconds - 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 - treatment with a strong cytochrome p450 (cyp3a4 inhibitor (within 14 days before first dose of study drug) or inducer (within 7 days before first dose of study drug) - received anti-rejection or immunomodulatory drugs (eg, anti-cytokines, btk inhibitors, jak inhibitors, pi3k inhibitors) within 30 days before randomization on study - concurrent participation in another clinical trial involving therapeutic interventions (observational study participation is acceptable) - any condition that confounds the ability to interpret data from the study - relevant renal impairment (egfr <60 ml/min) - any significant medical condition, laboratory abnormality or psychiatric illness that would interfere or prevent the subject from participating in the study

- respiratory failure at time of screening due to covid-19 - known cardio-pulmonary resuscitation within 14 days prior to randomization - pregnant or breast feeding - suspected uncontrolled active bacterial, fungal, viral, or other infection (besides infection with sars-cov-2) - alanine aminotransferase (alt) ≥ 3x upper limit of normal (uln) and total bilirubin > 2x uln - qtcf prolongation >480 milliseconds - 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 - treatment with a strong cytochrome p450 (cyp3a4 inhibitor (within 14 days before first dose of study drug) or inducer (within 7 days before first dose of study drug) - received anti-rejection or immunomodulatory drugs (eg, anti-cytokines, btk inhibitors, jak inhibitors, pi3k inhibitors) within 30 days before randomization on study - concurrent participation in another clinical trial involving therapeutic interventions (observational study participation is acceptable) - any condition that confounds the ability to interpret data from the study - any significant medical condition, laboratory abnormality or psychiatric illness that would interfere or prevent the subject from participating in the study

- respiratory failure at time of screening due to covid-19 - known cardio-pulmonary resuscitation within 14 days prior to randomization - pregnant or breast feeding - suspected uncontrolled active bacterial, fungal, viral, or other infection (besides infection with sars-cov-2) - alanine aminotransferase (alt) ≥ 3x upper limit of normal (uln) and total bilirubin > 2x uln - qtcf prolongation >480 milliseconds - 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 - treatment with a strong cytochrome p450 (cyp3a4 inhibitor (within 14 days before first dose of study drug) or inducer (within 7 days before first dose of study drug) - received anti-rejection or immunomodulatory drugs (eg, anti-cytokines, btk inhibitors, jak inhibitors, pi3k inhibitors) within 30 days before randomization on study - concurrent participation in another clinical trial involving therapeutic interventions (observational study participation is acceptable) - any condition that confounds the ability to interpret data from the study - any significant medical condition, laboratory abnormality or psychiatric illness that would interfere or prevent the subject from participating in the study