Sclerosing cholangitis is a rare, chronic, cholestatic liver disease caused by inflammation and fibrosis of the intrahepatic/extrahepatic biliary tract. Its pathophysiology involves destruction and stricture of the bile duct due to diffuse inflammation and fibrosis of the bile duct. The selected subjects will be randomly assigned to either active or placebo groups and administered 100 mg of HK-660S or placebo (1 tablet) twice a day for 12 weeks. After Visit 2, subjects will visit the study center at Week 4 (Visit 3), Week 8 (Visit 4), Week 12 (Visit 5 / End of Treatment), and Week 16 (Visit 6 / Follow-up) to assess efficacy and safety.
The objective of this study is to evaluate the improvement of bile duct strictures following the administration of HK-660S in patients with Primary Sclerosing Cholangitis(PSC). Percentage of subjects who show improvement of severity of PSC as assessed by Magnetic Resonance Cholangiopancreatography(MRCP) at Week 12 from baseline, with improvement defined as a decrease of -1 or more in the MRCP and change of alkaline phosphatase(ALP) level will be assessed at Week 12 from baseline.