Emerging drugs for the treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare immunemediated cholestatic disease for which no medical therapy has been shown to slow disease progression. Consequently, liver transplantation is the only lifesaving intervention for patients, and despite being a rare disease, PSC is the lead indication for transplantation across several European countries. The vast majority of patients (>70%) also develop inflammatory bowel disease (IBD) at some point in their lifetime, which imparts added lifetime risks of hepatobiliary malignancy and colorectal cancer. The rare disease nature, variable and often slow rates of disease progression (years rather than months), and lack of robust surrogate biomarkers for early stage yet high risk disease, represent critical challenges in trial design that have long precluded the development of effective medical treatment. However, the horizon for new treatments is encouraging, given innovative clinical trial programmes led by industry, alongside several investigatorinitiated studies. Herein, we outline the current platform of interventional trials in PSC, before discussing emerging areas of therapeutic interest.