Phase 2 Study of 500 mg BID NTZ on Top of Standard of Care in Patients With Acute Decompensation of Liver Cirrhosis at High Risk of Progression to Acute-on-Chronic Liver Failure or Established Acute-on-Chronic Liver Failure

Inclusion Criteria: Participants are eligible to be included in the study only if all of the following criteria apply: * Participants with liver cirrhosis of any underlying etiology (liver cirrhosis diagnosed by standard clinical criteria, imaging findings, and/or histology) * Recent acute clinical deterioration within 10 days prior to Day 1 defined as the onset of ascites, HE, gastrointestinal bleeding, or any combination of them with or without infection with or without organ failure * Adult male or female participants, defined as having reached the legal age of majority according to local regulations, aged \<75 years on the day of signing informed consent form (ICF) * Participants or legal representative willing and able to provide written informed consent in accordance with local ethical and legal requirements * Participants able to swallow peroral medication Exclusion Criteria: Participants are excluded from the study if any of the following criteria apply: 1. Known hypersensitivity to nitazoxanide or any known excipient of the IMP 2. Nitazoxanide use within 30 days prior to SCR 3. Uncontrolled acute bleeding at SCR or Day 1 4. Participants with poorly controlled seizure disorder 5. Severe circulatory failure requiring the use of high dose vasopressors (eg, dopamine \>15 μg/kg/min, or epinephrine \>0.1 μg/kg/min, or norepinephrine \>0.1 μg/kg/min); the use of terlipressin or low dose norepinephrine to treat hepatorenal syndrome is not an exclusion criterion 6. Uncontrolled severe infection with hemodynamic instability or shock 7. Need for renal replacement therapy (RRT) or any extracorporeal liver support device 8. Any significant disease considered to be potentially detrimental or would preclude the participant from participating in and completing the study as assessed by the PI 9. Individuals for whom the PI deems that study participation would be unsafe or not in the interest of the participant 10. Pregnancy or lactation 11. Participants of childbearing potential and non-sterile male participants who are not willing to use adequate contraception from SCR to 90 days after the final dose of IMP 12. Participation in another interventional clinical study within 30 days of SCR.