Clinical and radiological outcomes of ustekinumab in pediatric perianal Crohn’s disease: a multicenter retrospective study from the Pediatric IBD Porto Group of ESPGHAN

Abstract Background Perianal Crohn’s disease (pCD) is a severe pediatric phenotype with high morbidity. Although antitumor necrosis factor (TNF) agents are first-line therapy, remission is not achieved in a subset of patients. We aimed to evaluate clinical and radiological outcomes of ustekinumab (UST) in pediatric patients with pCD. Methods This is a multicenter retrospective study including pediatric patients with pCD treated with UST between 2016 and 2023. Primary outcomes were clinical and radiological remission at predefined time points. Clinical remission was defined as absence of fistula drainage without antibiotics or unplanned perianal interventions. Radiological remission was defined as a Pediatric MRI-Based perianal Crohn’s Disease (PEMPAC) score of  Results Fifty patients were included, of whom 2 were anti-TNF-naive. The median age at UST initiation was 15 years (IQR 12.4-16.2). Clinical remission was observed in 46% (23/50; P = .006 vs baseline), 48% (23/48; P = .036 vs baseline), and 42% (19/45; P = .13 vs baseline) at weeks 26, 52, and 104, respectively. Radiological remission was 29% (10/34) and 30% (13/43) at weeks 52 and 104, respectively (both P  Conclusions UST was associated with perianal clinical remission in a substantial proportion of pediatric patients, approaching 50% at 1 year, and radiological healing in about one-third at 2 years, supporting its potential role in pediatric pCD.