This is a Phase 1, open label, dose escalation clinical trial of human umbilical cord-derived mesenchymal stem cells for the treatment of decompensated cirrhosis. The purpose of this study is to assess the safety of human umbilical cord-derived mesenchymal stem cells in patients with decompensated cirrhosis.

The primary objective of this study is to assess the safety of intravenous infusion of human umbilical cord-derived mesenchymal stem cells in patients with decompensated cirrhosis.

Inclusion Criteria:

1. Willing to provide written informed consent;
2. Aged 18 to 75 years (including 18 and 75 years), male or female;
3. Patients diagnosed with decompensated liver cirrhosis based on clinical findings, laboratory tests, imaging findings and/or representative pathological findings (decompensated liver cirrhosis is defined as the occurrence of at least one serious complication, including esophageal and gastric varices bleeding, hepatic encephalopathy, ascites, spontaneous bacterial peritonitis and other serious complications);
4. Child-Turcotte-Pugh (CTP) score 7 to 12 points.

Exclusion Criteria:

1. Appearance of active variceal bleeding, overt hepatic encephalopathy (HE), refractory ascites or hepatorenal syndrome within 1 month prior to screening visit.
2. Uncontrolled severe infection within 2 weeks of screening.
3. Hepatitis B virus (HBV) DNA ≥ detection limit at the time of screening.
4. Patients with hepatitis B virus-related decompensated liver cirrhosis may discontinue antiviral therapy during the study, or those who with antiviral therapy for HBV for less than 12 months.
5. Patients with hepatitis C virus-related decompensated liver cirrhosis may discontinue antiviral therapy during the study, or those who with antiviral therapy for HCV for less than 12 months.
6. Patients under treatment with corticosteroids for autoimmune hepatitis for less than 6 months.
7. Trans-jugular intrahepatic portosystemic shunts (TIPS) insertion within 6 months prior to study inclusion.
8. Active drinkers with alcohol-related decompensated cirrhosis are unwilling to stop alcohol abuse after inclusion.
9. Severe jaundice (serum total bilirubin level ≥ 170μmol/L); Significant renal insufficiency (serum creatinine ≥ 1.2 times upper normal limit); Severe electrolyte abnormality (serum sodium level < 125 mmol/L); Severe leukopenia (white blood cell count < 1 × 10E9/L).
10. Patients with biliary obstruction, hepatic vein, portal vein, splenic vein thrombosis and portal vein spongiosis.
11. Patients with surgical history such as splenic cut-off flow and portal body shunt.
12. Patients with confirmed or suspected malignancies.
13. Patients with a prior history of major organ transplantation or complicated with significant disease of heart, lung, kidney, blood, endocrine and other systems.
14. Drug abuse, drug dependence and patients who receive methadone treatment or with psychosis.
15. HIV seropositivity.
16. Those who have received blood transfusion or other blood products within 1 month prior to screening visit.
17. Pregnancy, lactation or with recent fertility plan.
18. Highly allergic or have a history of severe allergies.
19. Participants in other clinical trials within the last 3 months.
20. Any other clinical condition which the investigator considers would make the patient unsuitable for the trial.

After approval from the steering committee and the Human Genetic Resources Administration of China, this trial data can be shared with qualifying researchers who submit a proposal with a valuable research question. A contract should be signed.