Infliximab Monotherapy Versus Infliximab and Azathioprine Combination Therapy in Patients with Ulcerative Colitis: A...

Area of Science:

• Gastroenterology
• Pharmacoeconomics
• Clinical Therapeutics

Background:

• Inflammatory bowel disease (IBD), including ulcerative colitis (UC), is rising in Western populations.
• Infliximab (IFX) is a standard treatment for severe UC.
• Combination therapy with IFX and azathioprine (AZA) improves outcomes but increases non-Hodgkin lymphoma (NHL) risk.

Purpose of the Study:

• To model the cost-effectiveness of combination therapy (IFX + AZA) versus IFX monotherapy for moderate-to-severe UC.
• To compare clinical outcomes and healthcare costs over a 5-year period.

Main Methods:

• A Markov model simulated 25-year-old UC patients over a 5-year horizon.
• Three treatment strategies were modeled: IFX monotherapy, continuous IFX+AZA, and 1-year IFX+AZA followed by IFX monotherapy.
• Outcomes measured included quality-adjusted life years (QALYs), disease flares, NHL incidence, and healthcare costs.

Main Results:

• Combination therapy yielded more QALYs and fewer flares than monotherapy.
• 1-year and continuous combination therapy showed comparable QALYs and flares.
• 1-year combination therapy had the lowest healthcare costs ($264,700) compared to monotherapy ($312,500) and continuous combination therapy ($265,400).
• NHL incidence was 0.188% for monotherapy, 0.207% for 1-year combination, and 1.121% for continuous combination therapy.

Conclusions:

• Combination therapy with IFX and AZA is a cost-saving strategy for moderate-to-severe UC.
• Both 1-year and continuous combination therapy offer comparable health outcomes.
• Short-term combination therapy may be preferred to maximize UC management benefits while mitigating long-term thiopurine risks.