Real-World Incidence of Suboptimal Response to Anti-Tumor Necrosis Factor Therapy for Ulcerative Colitis: A Nationwide Population-Based Study

Background/Aims: Although anti-tumor necrosis factor (TNF) agents have been widely used to treat ulcerative colitis (UC), the real-world incidence of suboptimal response to anti-TNF agents has not been thoroughly investigated, especially among Asians. Methods: Using the Korean National Health Insurance database, we collected data on UC patients who initiated anti-TNF agents between July 1, 2014, and June 30, 2017. We assessed suboptimal responses, including anti-TNF discontinuation or dose escalation, switching to other biologics, augmentation with a non-biologic therapy, and the requirement for colectomy. Results: A total of 1,268 patients were included as new anti-TNF users (infliximab 713, adalimumab 433, golimumab 122). The proportion of patients who experienced at least one suboptimal response within 1 year among all patients was 63.5%, including 59.1%, 69.5%, and 68.0% of patients treated with infliximab, adalimumab, and golimumab, respectively. The cumulative incidences of at least one suboptimal response over time were 41.5%, 63.7%, 80.5%, and 87.1% at 6, 12, 24, and 36 months, respectively. Cox proportional hazards modeling revealed that adalimumab was associated with a higher risk of at least one suboptimal response (hazard ratio [HR], 1.29; 95% confidence interval [CI], 1.13 to 1.48), dose escalation (HR, 4.35; 95% CI, 2.97 to 6.38) and discontinuation (HR, 1.25; 95% CI, 1.03 to 1.52) than infliximab. Golimumab was associated with a higher risk of switching to other biologics than infliximab (HR, 1.78; 95% CI, 1.21 to 2.60). Conclusions: More than half of Korean UC patients had suboptimal responses to anti-TNF agents within 1 year. UC patients treated with infliximab might be less prone to suboptimal responses than those treated with adalimumab or golimumab.