Nemolizumab for the Treatment of Moderate to Severe Chronic Hepatic Pruritus

Inclusion Criteria:

* Cholestatic pruritus secondary primary biliary sclerosis (PBS) or primary sclerosing cholangitis (PSC)
* Pruritus that is chronic in duration (greater equal to 6 months)
* Pruritus severity with a peak pruritus numerical rating score of ≥ 5 (moderate severity)
* Model for End-Stage Liver Disease (MELD) score \< 15. This will capture patients with chronic stable liver disease without significant comorbid conditions and/or signs of rapidly progressive or decompensated liver failure
* Willingness and ability to comply with scheduled clinic visits, physical exams, laboratory tests, questionnaires, effective contraception use, and other trial procedures

Exclusion Criteria:

* Pruritus due to a primary inflammatory skin dermatosis or other forms of psychogenic pruritus utilizing skin biopsies to exclude as needed
* Pregnant females. Urine pregnancy test required at screening
* History of intrahepatic cholestasis of pregnancy
* Any form of chronic hepatic pruritus associated with underlying malignancy
* Liver transplant recipients
* Drug-induced liver pruritus
* ALT or AST greater than 3 times the upper limit of normal or total bilirubin greater than 2 times upper normal limit
* Advanced liver disease indicators including, ascites requiring therapeutic paracentesis, history of spontaneous bacterial peritonitis, any grade of hepatic encephalopathy, or a documented history of variceal bleeding within the preceding six months
* Severe coagulopathy with INR \> 15
* Any form of acute cholestatic liver disease
* Allergy to nemolizumab or its ingredients
* Inability to provide informed consent