Infliximab Monotherapy Versus Infliximab and Azathioprine Combination Therapy in Patients with Ulcerative Colitis: A Cost-Effectiveness Analysis.

Abstract

Inflammatory bowel disease, encompassing ulcerative colitis (UC) and Crohn's disease, is increasing in prevalence in Western populations. Infliximab (IFX) is a standard treatment for severe UC. Evidence suggests combination therapy with IFX and azathioprine (AZA) improves clinical outcomes. However, AZA increases non-Hodgkin lymphoma (NHL) risk.We modeled the cost-effectiveness of combination therapy with IFX and AZA versus IFX monotherapy.We used a Markov model to simulate 25-year-old patients with UC over a 5-year time horizon in eight-week cycles. Patients received monotherapy, combination therapy for all 5 years ("continuous combination therapy"), or combination therapy for 1 year followed by monotherapy ("one-year combination therapy"). We measured quality-adjusted life years (QALYs) and costs of drug therapy, complications, and NHL.With monotherapy, patients experienced 3.263 QALYs and 6.84 flares; with 1-year combination therapy, 3.349 QALYs and 5.73 flares; and with continuous combination therapy, 3.351 QALYs and 5.67 flares. After 5 years, NHL incidence was 0.188% with monotherapy; 0.207% with 1-year combination therapy; and 1.121% with continuous combination therapy. Healthcare costs were $312,500 for monotherapy, $264,700 for 1-year combination therapy, and $265,400 for continuous combination therapy. Results were robust across sensitivity analyses.Combination therapy with IFX and AZA is a cost-saving strategy for moderate-to-severe UC, providing superior outcomes and lower costs compared to IFX monotherapy. Both 1-year and continuous combination therapy achieve comparable health outcomes. Short-term combination therapy may be preferable, as it captures the benefits of improved UC management while avoiding the deleterious effects of long-term exposure to thiopurines.

View details for DOI 10.1007/s10620-026-09761-5

View details for PubMedID 41723800

View details for PubMedCentralID 12158780