OBJECTIVES: Primary sclerosing cholangitis (PSC) is a rare, chronic cholestatic disease that can progress to cirrhosis, liver failure, and secondary cancers. Disease progression is typically non-linear, with no clearly defined milestones or disease stages. Several drugs are under investigation, but no economic model for PSC exists to evaluate the value of new treatments. The objective of this study was to develop an early economic model framework for PSC and validate through discussions with clinical and health economic experts.

METHODS: A Markov-cohort model was developed to simulate PSC progression over a lifetime time horizon. The framework for disease progression, as well as inputs for disease progression, mortality, and adverse events were determined by literature review. The preliminary model structure and input values were validated with 3 US clinical experts and 3 health economic experts. An alternative structure accounting for the complications of cancers secondary to PSC was also explored. Fibrosis staging was used to model disease progression for PSC-related liver complications. Model outcomes included overall and transplant-free survival, incidence of liver transplants (LTs), the rate of recurrent PSC (rPSC) and LTs after rPSC.

RESULTS: The conceptual model aligned upon with the experts estimated the overall survival for PSC patients to be 23.1 years and transplant-free survival to be 21.5 years, in line with values from the literature of 21.9 and 18.3 years, respectively. The estimated rate of LT in the lifetime of PSC patient was 14%. The rate of rPSC was estimated to be 3.39%. Within rPSC patients, the rate of second LT was estimated at 3%.

CONCLUSIONS: An early economic model framework was developed to replicate the progression of PSC. Model results validated the accuracy of the disease progression component of the model framework. This may serve as the foundation of models to evaluate the benefits of future treatments.