Declining use of combination infliximab and immunomodulator for inflammatory bowel disease in the community setting

To describe trends of combination therapy (CT) of infliximab (IFX) and immunomodulator (IMM) for inflammatory bowel disease (IBD) in the community setting.

A retrospective study was conducted of all IBD patients referred for IFX infusion to our community infusion center between 04/01/01 and 12/31/14. CT was defined as use of IFX with either azathioprine, 6-mercaptopurine, or methotrexate. We analyzed trends of CT usage overall, for Crohn's disease (CD) and ulcerative colitis (UC), and for the subgroups of induction patients. We also analyzed the trends of CT use in these groups over the study period, and compared the rates of CT use prior to and after publication of the landmark SONIC trial.

Of 258 IBD patients identified during the 12 year study period, 60 (23.3%) received CT, including 35 of 133 (26.3%) induction patients. Based on the Cochran-Armitage trend test, we observed decreasing CT use for IBD patients overall (P < 0.0001) and IBD induction patients, (P = 0.0024). Of 154 CD patients, 37 (24.68%) had CT, including 20 of 77 (26%) induction patients. The Cochran Armitage test showed a trend towards decreasing CT use for CD overall (P < 0.0001) and CD induction, (P = 0.0024). Overall, 43.8% of CD patients received CT pre-SONIC vs 7.4% post-SONIC (P < 0.0001). For CD induction, 40.0% received CT pre-SONIC vs 10.8% post-SONIC (P = 0.0035). Among the 93 patients with UC, 19 (20.4%) received CT. Of 50 induction patients, 14 (28.0%) received CT. The trend test of the 49 patients with a known year of induction again failed to demonstrate any significant trends in the use of CT (P = 0.6).

We observed a trend away from CT use in IBD. A disconnect appears to exist between expert opinion and evidence favoring CT with IFX and IMM, and evolving community practice.