Symptom Improvement of ulceRative colitis after an Induction dose of UStekinumab in Japanese clinical practice (SIRIUS), measured using patient-reported outcomes: a prospective observational study

INTRODUCTION: Ulcerative colitis (UC) is an idiopathic, chronic inflammatory disease of the large intestine. Ustekinumab is a monoclonal antibody against the p40 subunit of interleukin-12 and interleukin-23 and has proven efficacy in inducing and maintaining remission in adult patients with moderate-to-severe UC. In the Symptom Improvement of ulceRative colitis after an Induction dose of Ustekinumab study, we will document the initial treatment response (daily patient-reported outcomes for 8 weeks from first infusion) and treatment patterns of patients wih UC receiving an induction dose of ustekinumab in the real-world setting in Japan. We will also investigate the relationship between the treatment response at week 8 and early indicators of response and determine patient factors that may define the appropriate dosing interval for maintenance therapy. METHODS AND ANALYSIS: For this single-arm, prospective observational study at 24 centres in Japan with a follow-up period of 16/20 weeks, we aim to recruit 140 patients with moderate-to-severe UC between July 2021 and July 2022. All surveys will be conducted in Japanese and patient-reported outcomes relating to rectal bleeding, stool frequency, abdominal pain, nocturnal diarrhoea, tenesmus and perception of UC symptoms will be recorded using a smartphone application, where the patients can enter their initial response to ustekinumab induction therapy on a daily basis. Dosing intervals and the reasons for selecting this interval, and concomitant medications taken during treatment with ustekinumab will be collected by a physician questionnaire at the end of the study. On completion of primary end point (8-week patient-reported outcomes) data collection, results will be reported sequentially. ETHICS AND DISSEMINATION: The study has been approved by the ethics committee of each facility involved and the Institutional Review Board of the non-profit organisation MINS. TRIAL REGISTRATION NUMBER: UMIN000043753, NCT04963725.