• Currently receiving invasive mechanical ventilation
• Presence or suspicion of active malignancy with the exception of cancer in situ (e.g., skin cancer)
• Evidence of serious active infection other than COVID-19
• Current diagnosis of human immunodeficiency virus, hepatitis B or C
• Unlikely to survive for > 24 hours from enrollment
• Pregnant or might be pregnant, or who are currently breast-feeding
• Presence of significant comorbidity that, in the opinion of the investigator, predisposes the subject to mortality. Such conditions might include: New York Heart Association class IV Heart Failure, Hepatic dysfunction (i.e., AST or ALT >3x upper limit of normal), Renal dysfunction (i.e., estimated glomerular filtration rate (eGFR) < 50mL/min) or receiving renal replacement therapy
• Presence of septic shock at time of enrollment
• Hemoglobin < 80 g/L
• Evidence of neutropenia (i.e., absolute neutrophil count < 1000 cells/uL), lymphopenia (i.e., absolute lymphocyte count < 200 cells/uL) or thrombocytopenia (i.e.Platelets < 50×10^9/L)
• Hypersensitivity to TD-0903 or its components, or to other JAK inhibitors
• Treatment with anti-IL 6 (e.g., tocilizumab, sarilumab), anti-IL-6R antagonists (e.g., abatacept), JAK inhibitors (e.g., baricitinib, tofacitinib) supplemental interferon therapy, or tyrosine kinase inhibitors (e.g., erlotinib, gefinitib) in the past 30 days, or plans to receive a JAK inhibitor during the study period
• Current treatment with conventional synthetic disease-modifying anti-rheumatic drugs (DMARDs)/immunosuppressive agents including: Methotrexate, cyclosporine, mycophenolate, tacrolimus, penicillamine, or sulfasalazine within 2 weeks prior to enrollment, Azathioprine or cyclophosphamide within 12 weeks prior to enrollment , Monoclonal antibodies targeting B cells (e.g., rituximab) within 12 weeks prior to enrollment , Tumor necrosis factor-alpha (TNFα)) inhibitors within 4 weeks prior to enrollment
• Participating in other clinical trials involving any other experimental treatment for COVID-19, except in the context of a single-arm antiviral or convalescent plasma compassionate-use protocol
• Active or incompletely treated pulmonary tuberculosis, or known history of non-tuberculosis mycobacterium over past 12 months
• Requires continuous oxygen supplementation for underlying cardio-respiratory history in the past 90 day
• Body Mass Index ≥40 kg/m
• Receipt of live vaccine (i.e., live attenuated) in the 4 weeks prior to visit 1 or plans to receive a live vaccine (or live attenuated) during the study period. Note: Use of non-live (inactivated) vaccinations is allowed for all subjects
• History of venous thromboembolism (VTE), deep venous thrombosis (DVT), Pulmonary Embolism (PE) or known hypercoagulable disorder (e.g., factor V Leiden, antiphospholipid antibody syndrome, protein C or S deficiency)

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing willing stated in the publication: