BACKGROUND AND OBJECTIVESUlcerative colitis is highly prevalent in Canada and cost-effective ulcerative colitis therapies are warranted. Vedolizumab subcutaneous (SC) formulation was recently approved for ulcerative colitis maintenance therapy. We assessed vedolizumab SC cost effectiveness vs conventional and advanced therapeutics in patients with moderately to severely active ulcerative colitis from a Canadian public healthcare payer perspective.METHODSA hybrid decision tree/Markov model was developed to evaluate vedolizumab SC costs, quality-adjusted life-years, and cost effectiveness vs conventional therapy, adalimumab SC, infliximab intravenous, golimumab SC, tofacitinib, ustekinumab SC, and vedolizumab intravenous. This model predicts the number of patients achieving clinical response and remission after treatment induction, and sustained benefit during maintenance treatment. To account for statistical uncertainties, the base-case analysis was conducted in a probabilistic manner. Scenario analyses examined the impact of previous treatment with anti-tumor necrosis factor agents, dose escalation, loss of efficacy, and treatment adherence.RESULTSIn the base-case analysis, conventional therapy was the most cost-effective therapeutic option in the overall population. Vedolizumab SC was cost effective and dominant compared with other advanced therapies (adalimumab, golimumab, infliximab, tofacitinib 5 mg, ustekinumab, and vedolizumab intravenous). The annual vedolizumab SC cost per patient was reduced vs ustekinumab SC, tofacitinib 5 mg, vedolizumab intravenous, and golimumab SC by $47,024, $3251, $2120, and $2004 (Canadian dollars), respectively, and exceeded that of infliximab, adalimumab, and conventional therapy by $582, $3293, and $41,024, respectively. Among the treatments, vedolizumab SC generated the highest quality-adjusted life-years overall (14.21), which translated into the best incremental cost per quality-adjusted life-years gained over conventional therapy in the overall population ($109,374) and in anti-tumor necrosis factor-naïve and anti-tumor necrosis factor-experienced patients ($41,658/$114,287).CONCLUSIONSConventional therapy offered the most cost-effective therapeutic option followed by vedolizumab SC. Based on a $50,000/quality-adjusted life-year threshold, vedolizumab was cost effective in anti-tumor necrosis factor-naïve patients but not the overall population also when compared to conventional therapy.