P0732 A cost comparison of treatment sequencing for Ulcerative Colitis: vedolizumab vs ustekinumab as a second-line biologic in anti-TNF-exposed patients in Canada
Authors: Martin M , Zhou J Y , Mac S , Kao K E , Johnston K , Marshall J K 
Published: January 2025

Abstract

Background
Ulcerative colitis (UC) is a chronic inflammatory condition characterized by periods of relapse and remission. The main therapeutic goal is to induce and maintain remission to prevent long-term disease progression.1 Given the nature of the condition, patients often cycle through multiple treatments.2 The objective was to evaluate overall costs of treatment sequencing for anti-tumor necrosis factor (TNF)-exposed UC patients from a societal perspective in Canada.

Methods
A cost-comparison model was developed to investigate two treatment sequences in a hypothetical cohort of anti-TNF-exposed adult (≥ 18 years) UC patients: vedolizumab as a second-line biologic followed by ustekinumab vs. ustekinumab as a second-line biologic followed by vedolizumab. The model time horizon was based on the longest treatment duration from first-line anti-TNF to the end of third-line therapy, which was 8.23 years according to published sources. Treatment persistence was characterized by parametric time-to-discontinuation curves per line of therapy from published literature. Where multiple sources were identified, curves were fitted to pooled data. Treatment costs were based on dosing regimens described in Health Canada product monographs and parametric curves fitted to treatment persistence data. For fourth-line therapy and beyond, patients received a validated mix of subsequent treatment options including upadacitinib, mirikizumab, etrasimod, and colectomy. Costs of treatment, healthcare resource use, adverse event management, and productivity loss were aggregated, with total costs reported. Several scenario analyses assessed base case robustness; statistical testing was not conducted.

Results
All patients were treated with a first-line anti-TNF regimen for 1.97 years. Patients who then received second-line vedolizumab remained on second-line treatment longer versus those who received second-line ustekinumab (3.79 vs 2.52 years). Patients who received second-line vedolizumab subsequently received ustekinumab for 2.48 years (end of time horizon); for those receiving second-line ustekinumab, patients were subsequently treated with vedolizumab for 3.16 years and the composite mix for 0.59 years. Both treatment sequences yielded similar per-patient-per-year total costs: $203,107 for second-line vedolizumab and $201,988 for second-line ustekinumab.

Conclusion
Across lines of therapy, treatment persistence for vedolizumab has been reported as superior to ustekinumab. Given the comparable overall costs, the value to patients of extending the duration of earlier lines of therapy and slowing transition to later lines should be considered when treating moderate-to-severe UC.

References
1.Wetwittayakhlang P, Lontai L, Gonczi L, et al. Treatment Targets in Ulcerative Colitis: Is It Time for All In, including Histology? J Clin Med. 2021;10(23).
2.Bressler B. Is there an optimal sequence of biologic therapies for inflammatory bowel disease? Therap Adv Gastroenterol. 2023;16:17562848231159452.