Phase II Pilot Study of Cladribine (2-Chlorodeoxyadenosine; 2-CdA) for Early Stage Primary Sclerosing Cholangitis

PROTOCOL ENTRY CRITERIA: --Disease Characteristics-- Stage I-III primary sclerosing cholangitis Radiologically and pathologically documented No concomitant liver disease, e.g.: Viral hepatitis Autoimmune hepatitis Primary biliary cirrhosis Cirrhosis Portal hypertension or associated complications Jaundice caused by dominant stricture --Prior/Concurrent Therapy-- No concurrent immunosuppressives --Patient Characteristics-- Hematopoietic: Absolute neutrophil count at least 2500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 10 g/dL Other: No active infection No fistula abscess No active inflammatory bowel disease Quiescent disease allowed, including: Chronic ulcerative colitis Crohn's disease No other significant immunologic disorder No active malignancy No active alcohol or drug abuse No pregnant or nursing women Effective contraception required of fertile patients Endoscopic retrograde cholangiopancreatography within 36 months prior to registration Liver biopsy within 12 months prior to registration