Trends in Public Drug Plan Expenditures for Patients With Crohn Disease and Ulcerative Colitis Initiating Targeted Immune Modulator Therapy

The objective of this analysis was to examine the changes in drug expenditures with the initiation of targeted immune modulator (TIM) treatment in patients diagnosed with Crohn disease (CD) and ulcerative colitis (UC). Patient cohorts for CD and UC were identified from hospitalizations in Canada. Expenditure data for TIMs with a Health Canada–approved indication for the treatment of CD or UC were extracted from all provincial drug plans (except Quebec) and Yukon from 2016 to 2021, and a descriptive analysis was performed to assess the expenditure patterns. Annual expenditures on TIMs for patients with CD increased each year from 2016 to 2019 before decreasing in 2020 and 2021, whereas expenditures on TIMs in UC increased each year, generally by a greater percentage than was observed in CD (peak percentage growth of 92.5% for UC versus 15.9% for CD in 2018). Expenditures associated with TIM initiation among patients with CD and UC were driven by infliximab and adalimumab, with the 2 drugs accounting for nearly all expenditures in both indications in 2016 and most expenditures in 2021. In both CD and UC, vedolizumab expenditures increased over time, as did the proportions of TIM expenditures on ustekinumab in CD and tofacitinib in UC, albeit to a lesser extent than vedolizumab.