P249. Combination therapy with infliximab and thiopurines might reduce colectomy rates compared to infliximab monotherapy in patients with ulcerative colitis (UC)

U. Eriksson1, U.A. Janson1, H. Strid1, L. Öhman1, A. Bajor1

1Institute of Medicine, Sahlgrenska Academy, Sweden

Background: In the ACT 1 and 2 trials, infliximab therapy induced and maintained higher rates of remission compared to placebo in patients with UC. Colectomy rates were also lower (10% vs. 17%). The SUCCESS trial, on UC patients naïve to both anti TNF and AZA, or had stopped AZA 3 months before entry, demonstrated that combination therapy with thiopurines and infliximab was superior compared to monotherapy of either agent in inducing remission. We therefore investigated if combination therapy might reduce colectomy rates and disease activity more effectively than mono therapy with anti TNF.

Methods: We retrospectively studied the charts of patients who received infliximab therapy for corticosteroid- or thiopurine-resistant or steroid dependent UC in our outpatient clinics. Exclusion criteria were Crohn's disease, indeterminate colitis, previous biologic therapy and lost to follow up. The primary endpoints were colectomy and/or improvement rates. We defined improvement as the physicians global assessment including symtoms, endoscopy/rectoscopy or in some cases fecal calprotectin levels and if patients could stop corticosteroids.

Results: Thirty patients were included in the study, 12 females, mean age 38 years (SD = 14), disease duration 9 years (SD=9), number of infliximab treatments 6 (SD = 3.4). The colectomy rate was 11/30 and the improvement rate 15/30, four patients refused colectomy despite impairment. Sixteen patients were already on thiopurine therapy and two started concomitantly with infliximab, altogether 18 patients had combination therapy. Only one patient did not try thiopurines, eleven patients stopped because of side effects. 29 patients were treated with 5‑ASA and 20 were on corticosteroids.

The colectomy rate was significantly lower in patients receiving infliximab and thiopurines, 3/18 (17%) vs. those receiving only infliximab 8/12 (67%) (p < 0.01). The improvement rate was higher in the combo group, 13/18 (72%) compared to the monotherapy group with infliximab, 2/12 (17%) (p < 0.01). The colectomy rates were not affected by age, gender, disease duration, and initial CRP or calprotectin values.

In the combo group the calprotectin levels decreased during treatment (delta =1900 mg/kg, compared to the monotherapy group where calprotectin increased delta = −100 mg/kg, p < 0.05).

Conclusions: Combination therapy with infliximab and thiopurines seems to be superior compared to monotherapy to prevent colectomy and to reduce disease activity in patients with UC.