OBJECTIVES: Anti TNF-α agents (infliximab, adalimumab) are indicated for the second-line therapy in patients with inflammatory bowel disease (IBD). They are expected to achieve a sufficient treatment goal for IBD. However, we are not sure their clinical outcomes due to lack of evidences in Korean populations. This study aims to investigate treatment outcome such as loss of response(LOR) of anti TNF-α agents in real world settings.

METHODS: In this retrospective, population-based observational study, 5-year National Health Insurance claim data from 2010 to 2014 were used. Patients with ulcerative colitis (UC) and Crohn’s disease (CD)(ICD 10 codes K51 or K50) who were newly diagnosed and recorded anti TNF-α agent prescriptions during the study period were enrolled. Index date was defined as the first prescription day of anti TNF-α agents during 2010 to 2012. Subjects were follow-up for their clinical outcomes till end of the study period. LOR of anti TNF-α agent was defined as follows: increasing dose or shortening dose interval, switching to other anti TNF-α agent, discontinuation for at least 1 year, IBD-related operation, or administration of total parenteral nutrition. All data were analyzed using SAS software version 9.3.

RESULTS: During the overall study period (2010 to 2014), infliximab was more frequently used than adalimumab for UC and CD (85% and 81%). The numbers of anti TNF-α users during 2010 to 2012 were 807 and 2,119 patients for UC and CD, respectively. LOR was developed in 72.6% and 80.4% among anti TNF-α users with UC and CD during the study period. More than 60% of LOR was developed within the first year from index date. Among LOR criteria, anti-TNF-α discontinuation was top ranked in both UC and CD.

CONCLUSIONS: High LOR rate of anti TNF-α agents in IBD requires further treatment strategies in patients developed LOR to anti TNF-α agents.