Safety and Tolerability of A3907 in Primary Sclerosing Cholangitis

This study will test a drug called A3907 to see how safe and tolerated it is for treating people with Primary Sclerosing Cholangitis (PSC).

Key inclusion criteria:Clinical and radiological diagnosis of large-duct PSC via magnetic resonance cholangiopancreatography movement-related cortical potential (MRCP) or equivalent imaging modality that excludes biliary obstruction and malignancy within 6 months before screeningAlkaline phosphatase (ALP) > 1.5 × upper limit of normal (ULN) but ≤ 10 × ULNTotal bilirubin < 3 × ULNAspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 5 × ULNBaseline serum bile acid level at Screening must be > ULNClinically stable for at least 3 months prior to screeningKey exclusion criteria:Presence of documented secondary sclerosing cholangitis, small duct PSC, known or suspected overlapping clinical and histologic diagnosis of autoimmune hepatitis or other causes of chronic liver diseaseBiliary intervention within 3 months prior to study enrollment or plannedInflammatory bowel disease (IBD) with uncontrolled moderate to severe activity and/or on treatment with any immunosuppressive, immunomodulator, or biologic agent for treatment of IBD. Treatment with corticosteroids in the previous 4 weeksHistory of human immunodeficiency virus infection or any other known relevant infection (e.g., tuberculosis)History of colostomy or colectomyHistory of malignancy, including hepatocellular carcinoma within the past 10 years, except for basal or squamous cell carcinoma of the skin or carcinoma in situ of the cervix that has been successfully treatedHistory of transplants, including liver transplantation, or currently on active transplantation listKnown or suspected overlapping clinical and histologic diagnosis of autoimmune hepatitisLiver cirrhosis as assessed by any of the following:historical liver histology suspected liver fibrosisliver stiffness measurement, assessed by FibroScan (FibroScan value > 14.4 kPa)current or history of signs and symptoms of hepatic decompensation (including, but not limited to, jaundice, ascites, variceal haemorrhage, and/or hepatic encephalopathy)Treatment with rifampicin, CYP3A4 substrates, vitamin D or fibrates (unless patient is on a stable dose ≥ 6 months prior to baseline) and with medications that slow gastrointestinal motilityExposure to an investigational drug, biologic agent, or medical device within 30 days prior to Screening, or 5 half-lives of the study agent, whichever is longerPlatelet count < 150 000/mm3Albumin level < 3.0 g/dLInternational normalised ratio (INR) > 1.4 (the patient may be treated with vitamin K intravenously, and if INR is ≤ 1.4 at resampling, the patient may be enrolled)Advanced renal disease glomerular filtration rate (GFR) <70 mL/min/1.73 m2)