Inclusion Criteria:  Male or female patients aged ≥18 years Women of childbearing potential must have a negative serum pregnancy test to confirm eligibility Provision of signed written informed consent from the patient or patient's legally acceptable representative SARS-CoV-2 infection confirmed by RT-PCR laboratory test (which may include results from a test that was performed prior to hospital admission if, in the opinion of the Investigator, it is relevant to ongoing COVID-19)  Meet Berlin definition for moderate - severe ARDS  Bilateral opacities - not fully explained by effusions, lobar/lung collapse, or nodules Respiratory failure not fully explained by cardiac failure or fluid overload. PaO2/FIO2 ≤200 mmHg with PEEP ≥5 cmH2O Patient requires intubation or is currently intubated and has been for ≤48 hours  Exclusion Criteria:  Persistent septic shock (>24 hours) with a Mean Arterial Pressure (MAP) ≤65 mm Hg and serum lactate level >4 mmol/L (36 mg/dL) despite adequate volume resuscitation and vasopressor use (norepinephrine >0.2 μg/kg/min) for >6 hours Major trauma in the past 5 days Presence of any active malignancy (other than non-melanoma skin cancer) that required treatment within the last year Pre-existing severe cardiopulmonary disease including, but not limited to, interstitial lung disease; severe COPD (GOLD Stage IV or FEV1<30% predicted); heart failure (estimated left ventricular ejection fraction < 40%); or a chronic lung condition requiring home oxygen treatment An underlying clinical condition that, in the opinion of the Investigator, would make it very unlikely for the patient to be successfully weaned from ventilation due to severe underlying diseases (e.g., severe malnutrition, severe neurological disease) Patients considered inappropriate for critical care (e.g., being considered for palliative care) Currently receiving extracorporeal membrane oxygenation (ECMO) Severe chronic liver disease with Child-Pugh score >12 (Appendix 1) White blood count <2.5 x 109/L; Hemoglobin <4.0 mmol/L (6.5g/dL); Platelets <50 x 109/L ALT or AST >10x upper limit of normal (ULN) or bilirubin >3x ULN Women who are pregnant or breast-feeding Use of drugs with strong CYP3A4 induction potential, such as carbamazepine, efavirenz, enzalutamide, phenobarbital, phenytoin, hypericum, mitotane, nevirapine, primidone, rifabutin and rifampicin Inability of the ICU staff to initiate administration of study treatment within 48 hours of intubation Enrolled in a concomitant clinical trial of an investigational medicinal product In the opinion of the investigator, progression to death is highly probable, irrespective of the provision of treatments