Ustekinumab is effective for perianal fistulising Crohn's disease: a real-world experience and systematic review with meta-analysis

Background Perianal Crohn's disease (pCD) is a debilitating complication affecting up to 30% of Crohn's disease (CD) population, leading to increased morbidity, mortality and decreased quality of life. Despite the growing armamentarium of medications for luminal CD, their efficacy in pCD remains poorly studied. Aim To determine the efficacy of ustekinumab, a biologic approved for luminal CD, in pCD through a retrospective cohort study and systematic review. Methods A retrospective cohort study on patients with CD with active perianal fistulae treated with ustekinumab from September 2013 to August 2019 was performed to determine perianal fistula response and remission at 6 and 12 months after ustekinumab induction. A systematic review was performed to further establish rates of fistula response and remission with ustekinumab. Results At 6 months, 48.1% (13/27) patients achieved fistula response with none achieving fistula remission on provider exam, and 59.3% (16/27) achieved patient-reported symptomatic improvement with 3.7% (1/27) achieving symptomatic remission. At 1 year, on provider exam, 55.6% (5/9) had fistula response with none achieving fistula remission, and 100% (9/9) had symptomatic improvement with 22.2% (2/9) achieving symptomatic remission. There were no major safety signals during 1-year follow-up. The systematic review of 25 studies found 44% (92/209) of patients with active perianal fistulas had a clinical response within 6 months of follow-up, and 53.9% (85/152) of patients with 12 months of follow-up achieved clinical response. Conclusion Ustekinumab presents a safe and effective therapy for treatment of pCD. Prospective, randomised trials are needed to further elucidate long-term efficacy of ustekinumab for pCD.