Inclusion Criteria:  Male and female participants must be between 18 to 80 years of age inclusive, at the time of signing the informed consent. Participants who have documented PBC. Participants who have moderate to severe itch.  Exclusion Criteria:  Symptoms suggestive of active coronavirus disease 2019 (COVID-19) infection whilst symptoms persist or known COVID-19 positive contacts within the past 14 days should be excluded for at least 14 days from the exposure. Total bilirubin >2.0 times Upper Limit of Normal (ULN) using the average of two Baseline measures. Screening Alanine Aminotransferase (ALT) > 6 times ULN in a single Baseline measure or ALT > 5 times ULN using the average of two Baseline measures. Screening estimated glomerular filtration rate (eGFR) <30 milliliter per minute per 1.73 square meter (mL/min/1.73m^2). History or presence of hepatic decompensation (e.g., variceal bleeding, hepatic encephalopathy or ascites). Presence of actively replicating viral hepatitis B or C (HBV, HCV) infection, primary sclerosing cholangitis (PSC), alcoholic liver disease and/or confirmed hepatocellular carcinoma or biliary cancer. Current clinically significant diarrhea or active inflammatory ileal disease according to Investigator´s clinical judgment. Current symptomatic cholelithiasis or cholecystitis. Current diagnosis of primary skin disorders with itch symptoms (e.g., atopic dermatitis, psoriasis). Primary sleep disorders such as but are not limited to sleep apnea, narcolepsy, hypersomnia. Current/previous diagnosis of colorectal cancer. Initiation, discontinuation or change in dose of ursodeoxycholic acid (UDCA), bezafibrate or fenofibrate in the 8 weeks prior to Screening. Use of obeticholic acid: within 8 weeks prior to Screening. (Participants may not initiate or restart during the study). Initiation, discontinuation, or change in dose of any of the following in the 8 weeks prior to Screening: bile acid binding resins, rifampicin, naltrexone, naloxone, nalfurafine, pregabalin, gabapentin, sertraline or other selective serotonin reuptake inhibitor (SSRIs), antihistamines used for the treatment of itching. Administration of any other human ileal bile acid transporter (IBAT) inhibitor in the 12 weeks prior to screening. Any planned procedures intended to treat cholestatic pruritus such as nasobiliary drainage or ultraviolet light therapy from Screening and throughout the study. History of sensitivity or intolerance to the study treatment.