Durable clinical and deep remission with ustekinumab in perianal fistulizing Crohn's disease: A 2-year retrospective real-world cohort study.

Background and aims: Real-world evidence on ustekinumab for the treatment of perianal fistulizing Crohn's disease (PFCD) remains limited. This study assessed the long-term efficacy of ustekinumab in PFCD.

Methods: A total of 143 CD patients with perianal fistulas who initiated ustekinumab therapy were enrolled. Clinical remission was defined as the absence of pain and drainage from fistula tracts, as assessed by physicians. Deep remission was defined as concurrent clinical remission and radiological healing.

Results: The study population comprised 143 patients, with a mean age of 28.6 years and a mean number of prior perianal surgeries of 2.5. Overall, 77.6 % of patients had complex fistulas, and 65.7 % experienced prior biologic failure. During a median follow-up of 136.0 (108-156) weeks, 22/143 (18.5 %) patients discontinued ustekinumab therapy. Among patients with active PFCD, clinical remission was achieved in 88/119 (73.9 %) patients. Deep remission was achieved in 40 of 100 evaluable patients (40.0 %), typically 32.1 weeks after clinical remission. Multivariate analysis identified prior exposure to biological agents (hazard ratio [HR] = 0.38, 95 % confidence interval [CI]: 0.20-0.73, P = 0.004) and ileocolonic lesions (HR = 0.47, 95 % CI: 0.23-0.96, P = 0.040) as negative predictors of deep remission. Recurrence was rare (6.3 %), with a 2-year recurrence-free survival rate of 93.4 %.

Conclusions: Ustekinumab demonstrates remarkable efficacy in achieving sustained clinical and deep remission in PFCD. Prospective studies are warranted to confirm these findings.