Incidence of treatment discontinuation due to AEs [D10 in stage 1];Incidence; nature and severity of AEs and SAEs[D10 in stage 1];Changes in PaO2/FiO2 assessed by arterial blood gases and ventilator measures[end of infusion in stage 2]

Incidence of treatment discontinuation due to AEs [D10 in stage 1];Incidence; nature and severity of AEs and SAEs[D10 in stage 1];Changes in PaO2/FiO2 assessed by arterial blood gases and ventilator measures[end of infusion in stage 2]