A Randomized, Double-blinded, Placebo-controlled, Parallel-treatment Group, Adaptive Design, Multi-center, Phase 2b/3 Trial to Evaluate Efficacy and Safety of NuSepin® Intravenous Infusion in COVID-19 Pneumonia Patients

Inclusion Criteria:

1. An individual who or whose legally authorized representative has fully informed of all pertinent aspect of the trial and IMP, voluntarily decided to participate in the trial and adherence to the trial-related requirements, and provided a written informed consent
2. An adult man or woman aged between 19 years (or age of majority in his/her country) and 80 years.
3. A hospitalized patient with laboratory-confirmed SARS-CoV-2 infection by PCR test within 10 days (240 hours) prior to randomization.
4. At the time of randomization; whose clinical status is stage 4 (oxygenation by facial mask or nasal cannula) or 5 (non-invasive ventilation or high flow oxygen) on WHO 8-point ordinal scale
5. Pneumonia that satisfies all the following criteria at the time of randomization
6. Planned first dosing of the IMP not later than 2 days after the initiation of standard of care (SOC), when given in combination with SOC for severe Illness (according to NIH Clinical Spectrum of SARS-CoV-2 Infection)
7. A score of 5 points or more ("think sepsis") on the NEWS 2 scale at the time of randomization

Exclusion Criteria:

1. A patient whose clinical status is stage 3 or lower on the WHO 8-point ordinal scale (WHO 8-OS) at the time of randomization
2. An individual who requires endotracheal intubation, mechanical ventilation (WHO 8-OS stage 6), or extracorporeal membrane oxygen therapy (stage 7) at the time of randomization
3. A patient with multiorgan failure, shock, acute respiratory syndrome (ARDS)
4. A patient with renal dysfunction defined by eGFR less than 30mL/min/1.73m², or the use of hemodialysis or hemofiltration
5. Cholestatic liver disease (example: biliary obstruction, cholangitis, etc.) or hepatic dysfunction
6. Any of the following laboratory test results at the time of screening:
7. An individual with HIV-positive results or who requires antiviral treatments against active hepatitis (HBV, HCV) and etc.