Immunosuppression Withdrawal for Stable Pediatric Liver Transplant Recipients

Inclusion Criteria

• Subject and/or parent guardian must be able to understand and provide informed consent;
• Is the recipient of a living or deceased donor liver tx when subject was less than or equal to 6 years of age;
• Is at least 4 years post-tx at the time of study enrollment;
• Has normal allograft function defined as Alanine aminotransferase (ALT) < 50 IU/l and gamma-glutamyl transferase (GGT) < 50 IU/l;
• Has no evidence of acute rejection (AR) or chronic rejection (CR) within the past 2 years, based on medical history;
• Is stable on IS monotherapy with a calcineurin inhibitor (CNI);
• For female subjects of childbearing potential, subject must have a negative pregnancy test upon study entry;
• For female and male subjects with reproductive potential, subject must agree to use FDA approved methods of birth control for the duration of the study;
• Must be negative for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection within one year of enrollment;
• Must have screening biopsy that fulfills, based on central pathology reading, the following criteria:
• Portal inflammation and interface activity: Preferably absent, but minimal to focal mild portal mononuclear inflammation may be present. Interface necro-inflammatory activity is absent or equivocal/minimal and, if present, involves a minority of portal tracts.
• Centrizonal/peri-venular inflammation: Preferably absent, but minimal to focal mild perivenular mononuclear inflammation may be present. Perivenular necro-inflammatory activity is absent or equivocal/minimal and, if present, involves a minority of terminal hepatic venules.
• Bile duct changes: No lymphocytic bile duct damage, ductopenia and biliary epithelial senescence changes, unless there is an alternative, non-immunologic explanation (e.g. biliary strictures).
• Fibrosis: < Ishak Stage 3 (i.e. not more than occasional portal-to-portal bridging). Perivenular fibrosis should be less than "moderate", according to Banff Criteria.
• Arteries: Negative for obliterative or foam cell arteriopathy.

Exclusion Criteria

• Have received a liver tx for autoimmune liver disease, including autoimmune hepatitis or primary sclerosing cholangitis;
• Have received a liver tx for hepatitis B or hepatitis C;
• Have received a second organ transplant before, simultaneously, or after liver tx;
• Have a calculated glomerular filtration rate (modified Schwartz formula) of less than 60 mL/min/1.73 m^2;
• Have had a 50 percent (%) dose increase in CNI within 6 months of screening;
• Have discontinued a second IS agent within 12 months of screening;
• Have any systemic illness requiring or likely to require chronic or recurrent use of IS;
• Is pregnant or breastfeeding;
• Is unwilling or unable to adhere with study requirements and procedures;
• Have mental illness or history of drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements;
• Is unwilling or unable to provide consent or comply with the study protocol;
• Has used investigational drugs within 4 weeks of enrollment;
• Is receiving treatment for HIV infection;
• Has received any licensed or investigational live attenuated vaccine(s) within two months of enrollment;
• Has any medical condition that, in the opinion of the investigator, will interfere with safe participation in the trial.