P682 A Retrospective Comparison of Different Treatment Modalities in Patients with Chronic Pouchitis

Chronic pouchitis affects ~30% of patients post total colectomy with ileal pouch anal anastomosis (IPAA) surgery. Treatment with anti-TNF, anti-integrin α4β7, anti-IL-12/23, or Crohn's disease exclusion diet (CDED), have shown promise in different studies. We aimed to compare the efficacy of these treatments in a real-world context and to detect factors that can aid in treatment choices. A retrospective cohort study encompassing demographic, clinic, endoscopic, histologic and lab values of adult ulcerative colitis (UC) patients post-IPAA surgery with chronic pouchitis, treated with biologics or CDED at the Tel Aviv Medical Center. Data were collected at baseline, 12, 26, and 52 weeks of treatment. Primary outcomes were assessed using the modified Pouchitis Disease Activity Index (mPDAI). mPDAI response was defined as a reduction from baseline of ≥2 points, while mPDAI remission was defined as mPDAI response in addition to mPDAI score ≤4. Therapeutic interventions among 51 patients included CDED (n=10), vedolizumab (n=21), ustekinumab (n=7) and adalimumab (n=13) [Table 1]. At 12 and 26 weeks, overall mPDAI response rates were 52% and 48%, respectively, with no significant difference between groups. At 52 weeks, mPDAI response rates were significantly higher for ustekinumab and vedolizumab (60% and 55%, respectively) compared with adalimumab and CDED (27.3% and 0%, respectively), p=0.043. Fecal calprotectin reduction at week-26 was greatest for ustekinumab (93%), followed by vedolizumab (73%), adalimumab (55%), and CDED (-13%), p=0.003. Treatment persistence over 150 weeks was significantly higher for ustekinumab (100%) compared with adalimumab (46%), vedolizumab (33%), and CDED (20%), p<0.001 [Figure 1]. The predominant cause for treatment discontinuation was secondary loss of response (50%), followed by primary non-response and surgical complications (14.7% each), poor compliance (11.8%), side-effects (5.9%), and development of antibodies (2.9%). Patients without prior biologic or immunomodulator treatment for pouchitis had significantly higher mPDAI response rates at 12 weeks (90%, p=0.016 and 73.3%, p=0.03, respectively). Patients with surgical pouch complications showed a trend towards lower mPDAI-defined response rates at 12 weeks (25% vs. 64.7%; p = 0.064). Ustekinumab and vedolizumab demonstrate higher likelihood of maintaining long-term clinical and endoscopic response, along with greater reduction in fecal calprotectin compared with adalimumab and CDED. Biologic and immunomodulator therapy-naïve patients achieved higher induction response rates.