BackgroundFilgotinib was approved in Germany for treating patients with moderate to severe active ulcerative colitis in November 2021. It represents a preferential Janus kinase 1 inhibitor. The FilgoColitis study began recruiting immediately after approval and aims to assess filgotinib effectiveness under real-world conditions with a particular focus on patient-reported outcomes (PROs). The novelty of the study design is the optional inclusion of 2 innovative wearables, which could provide a new layer of patient-derived data.ObjectiveThe study investigates quality of life (QoL) and psychosocial well-being of patients with active ulcerative colitis during long-term exposure to filgotinib. PROs related to QoL and psychometric profiles (fatigue and depression) are collected alongside with disease activity symptom scores. We aim to evaluate physical activity patterns collected by wearables as an addition to traditional PROs, patient-reported health status, and QoL in different phases of disease activity.MethodsThis is a prospective, single-arm, multicentric, noninterventional, observational study with a sample size of 250 patients. QoL is assessed with validated questionnaires: the Short Inflammatory Bowel Disease Questionnaire (sIBDQ) for the disease-specific QoL, the EQ-5D for the general QoL, and the fatigue questionnaire (Inflammatory Bowel Disease-Fatigue [IBD-F]). Physical activity data are collected from patients using wearables (SENS motion leg sensor [accelerometry] and smartwatch, GARMIN vívosmart 4).ResultsThe enrollment started in December 2021 and was still open at the date of submission. After 6 months of study initiation, 69 patients were enrolled. The study is expected to be completed in June 2026.ConclusionsReal-world data for novel drugs are important to assess effectiveness outside of highly selected populations represented by randomized controlled trials. We examine whether patients’ QoL and other PROs can be supplemented with physical activity patterns measured objectively. Use of wearables with newly defined outcomes represents an additional observational tool for monitoring disease activity in patients with inflammatory bowel disease.Trial RegistrationGerman Clinical Trials Register DRKS00027327; https://drks.de/search/en/trial/DRKS00027327International Registered Report Identifier (IRRID)DERR1-10.2196/42574