* respiratory failure at time of screening as defined per protocol with any of these following therapies: * endotracheal intubation and mechanical ventilation * extracorporeal membrane oxygenation (ecmo) * high flow nasal cannula oxygen at flow rates ≥ 30 l/min and fraction of delivered oxygen ≥ 0.5 * non-invasive positive pressure ventilation * unable to swallow capsules or malabsorption syndrome, disease significantly affecting gastrointestinal function, or resection of the stomach or small bowel, symptomatic inflammatory bowel disease or ulcerative colitis, or partial or complete bowel obstruction * on a bruton's tyrosine kinase (btk)-inhibitor, anti-interleukin 6 (il6), anti-interleukin 6r (il6r), or janus kinase inhibitor (jaki) * has received rituximab within 180 days from study entry. * known bleeding disorders * major surgery within 4 weeks of study entry * participants in whom surgery is anticipated to be necessary within 72 hours * history of stroke or bleeding around or within brain within 6 months prior to enrollment * known history of human immunodeficiency virus (hiv) or active with hepatitis c virus (hcv) or hepatitis b virus (hbv) * currently active, clinically significant cardiovascular disease * asymptomatic arrythmias and or history of ejection fraction \< 40% on an echo * participants receiving a strong cytochrome p450 (cyp) 3a4 inhibitor with the exception of those receiving anti-fungal therapy/prophylaxis * chronic liver disease and hepatic impairment meeting child pugh class c * female participants who are pregnant, or breastfeeding, or planning to become pregnant while enrolled in this study or within 1 month of last dose of study drug. male participants who plan to father a child while enrolled in this study or within 3 months after the last dose of study drug. * unwilling or unable to participate in all required study evaluations and procedures * vaccinated with a live, attenuated vaccine within 4 weeks * uncontrolled high blood pressure * on therapeutic anticoagulation at baseline * participants with cancer, history of interstitial lung disease, and/or history of malignancies as defined in the protocol * co-enrolled in another interventional trial * aspartate aminotransferase (ast) or alanine aminotransferase (alt) ≥ 3.0 × uln, and total bilirubin \> 2.0 × uln * international normalized ratio (inr) ≥ 1.5 × uln attributable to coagulation disorders

* respiratory failure at time of screening as defined per protocol with any of these following therapies: * endotracheal intubation and mechanical ventilation * extracorporeal membrane oxygenation (ecmo) * high flow nasal cannula oxygen at flow rates ≥ 30 l/min and fraction of delivered oxygen ≥ 0.5 * non-invasive positive pressure ventilation * unable to swallow capsules or malabsorption syndrome, disease significantly affecting gastrointestinal function, or resection of the stomach or small bowel, symptomatic inflammatory bowel disease or ulcerative colitis, or partial or complete bowel obstruction * on a bruton's tyrosine kinase (btk)-inhibitor, anti-interleukin 6 (il6), anti-interleukin 6r (il6r), or janus kinase inhibitor (jaki) * has received rituximab within 180 days from study entry. * known bleeding disorders * major surgery within 4 weeks of study entry * participants in whom surgery is anticipated to be necessary within 72 hours * history of stroke or bleeding around or within brain within 6 months prior to enrollment * known history of human immunodeficiency virus (hiv) or active with hepatitis c virus (hcv) or hepatitis b virus (hbv) * currently active, clinically significant cardiovascular disease * asymptomatic arrythmias and or history of ejection fraction \< 40% on an echo * participants receiving a strong cytochrome p450 (cyp) 3a4 inhibitor with the exception of those receiving anti-fungal therapy/prophylaxis * chronic liver disease and hepatic impairment meeting child pugh class c * female participants who are pregnant, or breastfeeding, or planning to become pregnant while enrolled in this study or within 1 month of last dose of study drug. male participants who plan to father a child while enrolled in this study or within 3 months after the last dose of study drug. * unwilling or unable to participate in all required study evaluations and procedures * vaccinated with a live, attenuated vaccine within 4 weeks * uncontrolled high blood pressure * on therapeutic anticoagulation at baseline * participants with cancer, history of interstitial lung disease, and/or history of malignancies as defined in the protocol * co-enrolled in another interventional trial * aspartate aminotransferase (ast) or alanine aminotransferase (alt) ≥ 3.0 × uln, and total bilirubin \> 2.0 × uln * international normalized ratio (inr) ≥ 1.5 × uln attributable to coagulation disorders

respiratory failure at time of screening as defined per protocol with any of these following therapies: endotracheal intubation and mechanical ventilation extracorporeal membrane oxygenation (ecmo) high flow nasal cannula oxygen at flow rates ≥ 30 l/min and fraction of delivered oxygen ≥ 0.5 non-invasive positive pressure ventilation unable to swallow capsules or malabsorption syndrome, disease significantly affecting gastrointestinal function, or resection of the stomach or small bowel, symptomatic inflammatory bowel disease or ulcerative colitis, or partial or complete bowel obstruction on a bruton's tyrosine kinase (btk)-inhibitor, anti-interleukin 6 (il6), anti-interleukin 6r (il6r), or janus kinase inhibitor (jaki) has received rituximab within 180 days from study entry. known bleeding disorders major surgery within 4 weeks of study entry participants in whom surgery is anticipated to be necessary within 72 hours history of stroke or bleeding around or within brain within 6 months prior to enrollment known history of human immunodeficiency virus (hiv) or active with hepatitis c virus (hcv) or hepatitis b virus (hbv) currently active, clinically significant cardiovascular disease asymptomatic arrythmias and or history of ejection fraction < 40% on an echo participants receiving a strong cytochrome p450 (cyp) 3a4 inhibitor with the exception of those receiving anti-fungal therapy/prophylaxis chronic liver disease and hepatic impairment meeting child pugh class c female participants who are pregnant, or breastfeeding, or planning to become pregnant while enrolled in this study or within 1 month of last dose of study drug. male participants who plan to father a child while enrolled in this study or within 3 months after the last dose of study drug. unwilling or unable to participate in all required study evaluations and procedures vaccinated with a live, attenuated vaccine within 4 weeks uncontrolled high blood pressure on therapeutic anticoagulation at baseline participants with cancer, history of interstitial lung disease, and/or history of malignancies as defined in the protocol co-enrolled in another interventional trial aspartate aminotransferase (ast) or alanine aminotransferase (alt) ≥ 3.0 × uln, and total bilirubin > 2.0 × uln international normalized ratio (inr) ≥ 1.5 × uln attributable to coagulation disorders

respiratory failure at time of screening as defined per protocol with any of these following therapies: endotracheal intubation and mechanical ventilation extracorporeal membrane oxygenation (ecmo) high flow nasal cannula oxygen at flow rates ≥ 30 l/min and fraction of delivered oxygen ≥ 0.5 non-invasive positive pressure ventilation unable to swallow capsules or malabsorption syndrome, disease significantly affecting gastrointestinal function, or resection of the stomach or small bowel, symptomatic inflammatory bowel disease or ulcerative colitis, or partial or complete bowel obstruction on a bruton's tyrosine kinase (btk)-inhibitor, anti-interleukin 6 (il6), anti-interleukin 6r (il6r), or janus kinase inhibitor (jaki) has received rituximab within 180 days from study entry. known bleeding disorders major surgery within 4 weeks of study entry participants in whom surgery is anticipated to be necessary within 72 hours history of stroke or bleeding around or within brain within 6 months prior to enrollment known history of human immunodeficiency virus (hiv) or active with hepatitis c virus (hcv) or hepatitis b virus (hbv) currently active, clinically significant cardiovascular disease asymptomatic arrythmias and or history of ejection fraction < 40% on an echo participants receiving a strong cytochrome p450 (cyp) 3a4 inhibitor with the exception of those receiving anti-fungal therapy/prophylaxis chronic liver disease and hepatic impairment meeting child pugh class c female participants who are pregnant, or breastfeeding, or planning to become pregnant while enrolled in this study or within 1 month of last dose of study drug. male participants who plan to father a child while enrolled in this study or within 3 months after the last dose of study drug. unwilling or unable to participate in all required study evaluations and procedures vaccinated with a live, attenuated vaccine within 4 weeks uncontrolled high blood pressure on therapeutic anticoagulation at baseline participants with cancer, history of interstitial lung disease, and/or history of malignancies as defined in the protocol co-enrolled in another interventional trial aspartate aminotransferase (ast) or alanine aminotransferase (alt) ≥ 3.0 × uln, and total bilirubin > 2.0 × uln international normalized ratio (inr) ≥ 1.5 × uln attributable to coagulation disorders

- respiratory failure at time of screening as defined per protocol with any of these following therapies: - endotracheal intubation and mechanical ventilation. - extracorporeal membrane oxygenation (ecmo). - high flow nasal cannula oxygen at flow rates >=30 l/min and fraction of delivered oxygen >= 0.5. - non-invasive positive pressure ventilation. - unable to swallow capsules or malabsorption syndrome, disease significantly affecting gastrointestinal function, or resection of the stomach or small bowel, symptomatic inflammatory bowel disease or ulcerative colitis, or partial or complete bowel obstruction. - on a btk-inhibitor, anti-il6, anti-il6r, or janus kinase inhibitor (jaki). - has received rituximab within 180 days from study entry. - known bleeding disorders. - major surgery within 4 weeks of study entry. - participants in whom surgery is anticipated to be necessary within 72 hours. - history of stroke or bleeding around or within brain within 6 months prior to enrollment. - known history of human immunodeficiency virus (hiv) or active with hepatitis c virus (hcv) or hepatitis b virus (hbv). - currently active, clinically significant cardiovascular disease. - asymptomatic arrythmias and or history of ejection fraction < 40% on an echo. - participants receiving a strong cytochrome p450 (cyp) 3a4 inhibitor with the exception of those receiving anti-fungal therapy/prophylaxis. - chronic liver disease and hepatic impairment meeting child pugh class c. - female participants who are pregnant, or breastfeeding, or planning to become pregnant while enrolled in this study or within 1 month of last dose of study drug. male participants who plan to father a child while enrolled in this study or within 3 months after the last dose of study drug. - unwilling or unable to participate in all required study evaluations and procedures. - vaccinated with a live, attenuated vaccine within 4 weeks. - uncontrolled high blood pressure. - on therapeutic anticoagulation at baseline. - participants with cancer. - co-enrolled in another interventional trial.

- respiratory failure at time of screening as defined per protocol with any of these following therapies: - endotracheal intubation and mechanical ventilation. - extracorporeal membrane oxygenation (ecmo). - high flow nasal cannula oxygen at flow rates >=30 l/min and fraction of delivered oxygen >= 0.5. - non-invasive positive pressure ventilation. - unable to swallow capsules or malabsorption syndrome, disease significantly affecting gastrointestinal function, or resection of the stomach or small bowel, symptomatic inflammatory bowel disease or ulcerative colitis, or partial or complete bowel obstruction. - on a btk-inhibitor, anti-il6, anti-il6r, or janus kinase inhibitor (jaki). - has received rituximab within 180 days from study entry. - known bleeding disorders. - major surgery within 4 weeks of study entry. - participants in whom surgery is anticipated to be necessary within 72 hours. - history of stroke or bleeding around or within brain within 6 months prior to enrollment. - known history of human immunodeficiency virus (hiv) or active with hepatitis c virus (hcv) or hepatitis b virus (hbv). - currently active, clinically significant cardiovascular disease. - asymptomatic arrythmias and or history of ejection fraction < 40% on an echo. - participants receiving a strong cytochrome p450 (cyp) 3a4 inhibitor with the exception of those receiving anti-fungal therapy/prophylaxis. - chronic liver disease and hepatic impairment meeting child pugh class c. - female participants who are pregnant, or breastfeeding, or planning to become pregnant while enrolled in this study or within 1 month of last dose of study drug. male participants who plan to father a child while enrolled in this study or within 3 months after the last dose of study drug. - unwilling or unable to participate in all required study evaluations and procedures. - vaccinated with a live, attenuated vaccine within 4 weeks. - uncontrolled high blood pressure. - on therapeutic anticoagulation at baseline. - participants with cancer. - co-enrolled in another interventional trial.