* respiratory failure requiring mechanical ventilation. * in the opinion of the investigator, progression to mechanical ventilation or death is imminent and inevitable within the next 24 hours. * valid do not intubate (dni) or do not resuscitate (dnr) order. * anticipated duration of hospital stay \< 72 hours. * history of allergy or hypersensitivity reaction to any component of the ip. * participation in another clinical study with an ip within 4 weeks prior to day 1 or within 5 half-lives of the ip, whichever is longer. (participation in covid-19 antiviral or antimalarial trials may be permitted after discussion with the medical monitor). * liver cirrhosis or liver failure. * known human immunodeficiency virus infection. * known hepatitis b or known hepatitis c infection in the absence of a history of curative therapy. * known or suspect active or latent tuberculosis infection. * active bacterial, fungal, viral, or other infection (besides covid-19). * clinically significant cardiac disease within 6 months. * history of severely impaired respiratory function at baseline (not related to covid-19) based on requirement for home oxygen of \> 4 l/min or based on other medical history known to the investigator. * history of cancer within 12 months of enrollment. * receipt of chemotherapy, biologic immunomodulators (including jak inhibitors), or immunosuppressive therapies within 8 weeks of enrollment, or receipt of rituximab or other b cell-depleting mab therapy within 6 months. note: other protocol defined exclusion criteria apply

* respiratory failure requiring mechanical ventilation. * in the opinion of the investigator, progression to mechanical ventilation or death is imminent and inevitable within the next 24 hours. * valid do not intubate (dni) or do not resuscitate (dnr) order. * anticipated duration of hospital stay \< 72 hours. * history of allergy or hypersensitivity reaction to any component of the ip. * participation in another clinical study with an ip within 4 weeks prior to day 1 or within 5 half-lives of the ip, whichever is longer. (participation in covid-19 antiviral or antimalarial trials may be permitted after discussion with the medical monitor). * liver cirrhosis or liver failure. * known human immunodeficiency virus infection. * known hepatitis b or known hepatitis c infection in the absence of a history of curative therapy. * known or suspect active or latent tuberculosis infection. * active bacterial, fungal, viral, or other infection (besides covid-19). * clinically significant cardiac disease within 6 months. * history of severely impaired respiratory function at baseline (not related to covid-19) based on requirement for home oxygen of \> 4 l/min or based on other medical history known to the investigator. * history of cancer within 12 months of enrollment. * receipt of chemotherapy, biologic immunomodulators (including jak inhibitors), or immunosuppressive therapies within 8 weeks of enrollment, or receipt of rituximab or other b cell-depleting mab therapy within 6 months. note: other protocol defined exclusion criteria apply

- respiratory failure requiring mechanical ventilation. - in the opinion of the investigator, progression to mechanical ventilation or death is imminent and inevitable within the next 24 hours. - valid do not intubate (dni) or do not resuscitate (dnr) order. - anticipated duration of hospital stay < 72 hours. - history of allergy or hypersensitivity reaction to any component of the ip. - participation in another clinical study with an ip within 4 weeks prior to day 1 or within 5 half-lives of the ip, whichever is longer. (participation in covid-19 antiviral or antimalarial trials may be permitted after discussion with the medical monitor). - liver cirrhosis or liver failure. - known human immunodeficiency virus infection. - known hepatitis b or known hepatitis c infection in the absence of a history of curative therapy. - known or suspect active or latent tuberculosis infection. - active bacterial, fungal, viral, or other infection (besides covid-19). - clinically significant cardiac disease within 6 months. - history of severely impaired respiratory function at baseline (not related to covid-19) based on requirement for home oxygen of > 4 l/min or based on other medical history known to the investigator. - history of cancer within 12 months of enrollment. - receipt of chemotherapy, biologic immunomodulators (including jak inhibitors), or immunosuppressive therapies within 8 weeks of enrollment, or receipt of rituximab or other b cell-depleting mab therapy within 6 months. note: other protocol defined exclusion criteria apply

- respiratory failure requiring mechanical ventilation. - in the opinion of the investigator, progression to mechanical ventilation or death is imminent and inevitable within the next 24 hours. - valid do not intubate (dni) or do not resuscitate (dnr) order. - anticipated duration of hospital stay < 72 hours. - history of allergy or hypersensitivity reaction to any component of the ip. - participation in another clinical study with an ip within 4 weeks prior to day 1 or within 5 half-lives of the ip, whichever is longer. (participation in covid-19 antiviral or antimalarial trials may be permitted after discussion with the medical monitor). - liver cirrhosis or liver failure. - known human immunodeficiency virus infection. - known hepatitis b or known hepatitis c infection in the absence of a history of curative therapy. - known or suspect active or latent tuberculosis infection. - active bacterial, fungal, viral, or other infection (besides covid-19). - clinically significant cardiac disease within 6 months. - history of severely impaired respiratory function at baseline (not related to covid-19) based on requirement for home oxygen of > 4 l/min or based on other medical history known to the investigator. - history of cancer within 12 months of enrollment. - receipt of chemotherapy, biologic immunomodulators (including jak inhibitors), or immunosuppressive therapies within 8 weeks of enrollment, or receipt of rituximab or other b cell-depleting mab therapy within 6 months. note: other protocol defined exclusion criteria apply