BACKGROUND/AIMS Combination therapy with immunomodulators (IMMs) was proposed as a strategy to prevent the development of loss of response (LOR) to anti-tumor necrosis factor (TNF) for patients with inflammatory bowel disease (IBD). However, the effect is unclear in patients already exposed to IMMs. The aim of this study was to evaluate whether combination therapy with IMMs is superior to monotherapy for prevention of LOR to anti-TNF.

METHODS This was a retrospective study of patients in Seoul National University Bundang Hospital with IBD between January 2009 and October 2018. LOR was defined as clinical deterioration after maintenance of anti-TNF for at least 6 months. We investigated the difference in incidence of LOR to anti-TNF between the monotherapy and combination groups. We additionally assessed factors affecting LOR development to anti-TNF.

RESULTS A total of 116 patients with IBD were included in this study (monotherapy 61 patients; combination 55 patients). Overall, LOR to anti-TNF occurred in 31 patients during the follow-up period. The combination of an anti-TNF agent and IMM showed no significant difference in the incidence of LOR compared to anti-TNF agent monotherapy (hazard ratio [HR], 1.64; 95% confidence interval [CI], 0.786 to 3.148; p = 0.182). Female sex was significantly associated with the development of LOR to anti-TNF (HR, 3.032; 95% CI, 1.467 to 6.268; p = 0.003).

CONCLUSION Anti-TNF and IMM combination therapy did not prove efficacious in preventing the development of LOR in IBD patients. Female sex was associated with the development of LOR to anti-TNF; further studies are required to confirm these results.