inclusion criteria: hospitalized adult male or non-pregnant, non-lactating female subjects (between 18 and 80 years), with sars-cov-2 (previously known as 2019-ncov) infection that is documented by authorized diagnostic pcr test. a rapid pcr test could also be used. confirmation that subject has covid-19 within the last 2 weeks prior to randomization. meeting who covid 19 clinical improvement ordinal scale criteria 5 (non-invasive mechanical ventilation or high-flow oxygen) or criteria 6 (intubation and mechanical ventilation). o2 sat <= 93% male subjects and female subjects of childbearing potential must agree to use protocol specified methods of contraception. female subjects of childbearing potential and women of non childbearing potential (defined as at least 2 years postmenopausal or permanently sterilized women [bilateral tubal ligation, bilateral ovariectomy, or hysterectomy]) must have a negative serum pregnancy test at screening or pretreatment on day 1. the subject or a lar has provided written informed consent. the subject or the lar is aware of the investigational nature of this study and willing to comply with protocol treatments, and other evaluations listed in the icf.

inclusion criteria: hospitalized adult male or non-pregnant, non-lactating female subjects (between 18 and 80 years), with sars-cov-2 (previously known as 2019-ncov) infection that is documented by authorized diagnostic pcr test. a rapid pcr test could also be used. confirmation that subject has covid-19 within the last 2 weeks prior to randomization. meeting who covid 19 clinical improvement ordinal scale criteria 5 (non-invasive mechanical ventilation or high-flow oxygen) or criteria 6 (intubation and mechanical ventilation). o2 sat <= 93% male subjects and female subjects of childbearing potential must agree to use protocol specified methods of contraception. female subjects of childbearing potential and women of non childbearing potential (defined as at least 2 years postmenopausal or permanently sterilized women [bilateral tubal ligation, bilateral ovariectomy, or hysterectomy]) must have a negative serum pregnancy test at screening or pretreatment on day 1. the subject or a lar has provided written informed consent. the subject or the lar is aware of the investigational nature of this study and willing to comply with protocol treatments, and other evaluations listed in the icf.

inclusion criteria: 1. hospitalized adult male or non-pregnant, non-lactating female subjects (between 18 and 80 years), with sars-cov-2 (previously known as 2019-ncov) infection that is documented by authorized diagnostic pcr test. a rapid pcr test could also be used. confirmation that subject has covid-19 within the last 2 weeks prior to randomization. 2. meeting who covid 19 clinical improvement ordinal scale criteria 5 (non-invasive mechanical ventilation or high-flow oxygen) or criteria 6 (intubation and mechanical ventilation). 3. o2 sat <= 93% 4. male subjects and female subjects of childbearing potential must agree to use protocol specified methods of contraception. 5. female subjects of childbearing potential and women of non childbearing potential (defined as at least 2 years postmenopausal or permanently sterilized women [bilateral tubal ligation, bilateral ovariectomy, or hysterectomy]) must have a negative serum pregnancy test at screening or pretreatment on day 1. 6. the subject or a lar has provided written informed consent. 7. the subject or the lar is aware of the investigational nature of this study and willing to comply with protocol treatments, and other evaluations listed in the icf.

inclusion criteria: 1. hospitalized adult male or non-pregnant, non-lactating female subjects (between 18 and 80 years), with sars-cov-2 (previously known as 2019-ncov) infection that is documented by authorized diagnostic pcr test. a rapid pcr test could also be used. confirmation that subject has covid-19 within the last 2 weeks prior to randomization. 2. meeting who covid 19 clinical improvement ordinal scale criteria 5 (non-invasive mechanical ventilation or high-flow oxygen) or criteria 6 (intubation and mechanical ventilation). 3. o2 sat <= 93% 4. male subjects and female subjects of childbearing potential must agree to use protocol specified methods of contraception. 5. female subjects of childbearing potential and women of non childbearing potential (defined as at least 2 years postmenopausal or permanently sterilized women [bilateral tubal ligation, bilateral ovariectomy, or hysterectomy]) must have a negative serum pregnancy test at screening or pretreatment on day 1. 6. the subject or a lar has provided written informed consent. 7. the subject or the lar is aware of the investigational nature of this study and willing to comply with protocol treatments, and other evaluations listed in the icf.