inclusion criteria: able and willing to give signed informed consent hospitalized less than 48 hours with pneumonia and confirmed covid-19 disease meet the criteria for severe covid_19 disease at randomization defined as patients that have one or more of the following: oxygen saturation as detected by pulse oximeter (spo2) < 94% on room air at sea level ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (pao2/fio2) < 300 mm hg respiratory rate > 30 breaths/min lung infiltrates involving > 50% of lung parenchyma score of 5 or 6 on the who covid-19 10-point clinical progression scale (cps) at randomization female patients of reproductive potential must be on an effective contraceptive method

inclusion criteria: able and willing to give signed informed consent hospitalized less than 48 hours with pneumonia and confirmed covid-19 disease meet the criteria for severe covid_19 disease at randomization defined as patients that have one or more of the following: oxygen saturation as detected by pulse oximeter (spo2) < 94% on room air at sea level ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (pao2/fio2) < 300 mm hg respiratory rate > 30 breaths/min lung infiltrates involving > 50% of lung parenchyma score of 5 or 6 on the who covid-19 10-point clinical progression scale (cps) at randomization female patients of reproductive potential must be on an effective contraceptive method