Efficacy of Ustekinumab on perianal fistulizing Crohn’s disease: a retrospective single-center real-world analysis

Abstract Aim: Data of Ustekinumab (UST) in treating perianal fistulizing Crohn’s disease (CD) are limited in China. We aimed to evaluate the efficacy of UST in the real-world setting. Methods: We retrospectively analyzed patients with perianal fistulizing CD and receiving UST treatment from March 1, 2020 to October 30, 2021. Patients’ characteristics, biomarker, and imaging were extracted from digital databases. Results: Twenty patients were eligible (18 males; mean age of 29.4±2.6 years; mean disease duration of 6.3±0.9 years; 45.0% diagnosed as complex fistula; mean baseline Van Assche score of 7.7±1.1). Perianal Crohn’s disease activity index (5.4±1.0 vs 8.7±1.0, P=0.027) and Crohn’s anal fistula quality of life (29.4±4.8 vs 38.9±4.2, P=0.011) reduced significantly. Clinical remission appeared in 60.0% and clinical response in 85.0%; clinical fistula remission in 30.0%, clinical fistula response in 35.0%, and no response in 35.0% of patients. Eight patients received post-treatment MRI. Healing, partial response, no change, and deterioration appeared in 37.5%, 25.0%, 12.5% and 25.0% of the patients, respectively. The cut-off UST trough concentration predicting clinical fistula remission was 2.6 μg/ml (an area under the curve of 0.821, sensitivity 66.7%, specificity 85.7%). Conclusions: UST is efficacious in promoting clinical and radiological fistula remission in patients with CD.