Combination Therapy With Ursodeoxycholic Acid (UDCA) and All-Trans Retinoic Acid (ATRA) for Treatment of Primary Sclerosing Cholangitis

"The subjects will continue to take their current dose of UDCA (15 mg/kg/day), as per ongoing clinical care, and need to be on a stable dose of UDCA for at least six months prior to enrollment.~The specific intervention is the addition of daily oral ATRA (45 mg/m\^2) divided into 2 doses. To increase adherence to the dosing regimen, the drug will be compounded by the Research Pharmacies of Yale and Mayo into 2 formulations (30 mg and 40 mg capsules), and an Investigational New Drug (IND) permit was obtained for this process."