Difference in Time to Clinical Improvement (TTCI) [Censored at Day 29] [Time Frame: up to 29 days] between the 2 treatment and the placebo group. The primary endpoint parameter is time to clinical improvement (censored at Day 29), defined as the time (in days) from randomization of study treatment (NuSepin or placebo) until a decline of two categories on a six-category ordinal scale* of clinical status (1 ꞊ complete clinical remission, 6 ꞊ death) * Six-category ordinal scale: 6. Death, 5. ICU, requiring ECMO and/or IMV, 4. ICU/hospitalization, requiring NIV/ HFNC therapy, 3. Hospitalization, requiring supplemental oxygen (such as LFNC or facial mask), 2. Hospitalization, not requiring supplemental oxygen, 1. Complete clinical remission, i.e. fever, respiratory rate, oxygen saturation return to normal, and cough relief). Abbreviations: IMV= invasive mechanical ventilation, NIV= non-invasive mechanical ventilation, HFNC= High-flow nasal cannula, LFNC= Low-flow nasal cannula.

Difference in Time to Clinical Improvement (TTCI) [Censored at Day 29] [Time Frame: up to 29 days] between the 2 treatment and the placebo group. The primary endpoint parameter is time to clinical improvement (censored at Day 29), defined as the time (in days) from randomization of study treatment (NuSepin or placebo) until a decline of two categories on a six-category ordinal scale* of clinical status (1 ꞊ complete clinical remission, 6 ꞊ death) * Six-category ordinal scale: 6. Death, 5. ICU, requiring ECMO and/or IMV, 4. ICU/hospitalization, requiring NIV/ HFNC therapy, 3. Hospitalization, requiring supplemental oxygen (such as LFNC or facial mask), 2. Hospitalization, not requiring supplemental oxygen, 1. Complete clinical remission, i.e. fever, respiratory rate, oxygen saturation return to normal, and cough relief). Abbreviations: IMV= invasive mechanical ventilation, NIV= non-invasive mechanical ventilation, HFNC= High-flow nasal cannula, LFNC= Low-flow nasal cannula.