BACKGROUND: The treatment landscape for active ulcerative colitis is rapidly evolving and current real-world evidence on response to advanced therapy is limited. This study aimed to determine indicators of inadequate therapeutic response among patients with ulcerative colitis in Germany initiating advanced therapy. METHODS: This retrospective analysis used German claims data (2015-2022) from adult patients (>/= 18 years). The prevalence and incidence of ulcerative colitis (ICD-10-GM: K51.X) were estimated. Inadequate response to therapy was evaluated in patients initiating advanced therapy based on eight predefined indicators observed for 12 months following dispensation of index treatment. RESULTS: Mean ulcerative colitis patient age in 2016-2022 ranged from 49.6 to 51.5 years, 47.6%-48.3% were female. Administrative prevalence ranged from 0.45% in 2016 to 0.53% in 2022. The number of patients initiating advanced treatment ranged from 157 to 347 across the study years (3.2%-4.9% of overall treated study population). On average from 2016-2021, 78.8% had inadequate response in the 12 months following index treatment. Common indicators included prolonged use of corticosteroids (46.2%) and augmentation with conventional therapies (43.9%). CONCLUSIONS: Adult ulcerative colitis patients showed a high prevalence of inadequate response to advanced therapies. Our findings reveal a need for improved UC advanced therapy options, providing insight into inadequate response patterns. This may help identify patients who could benefit from a change in therapy to improve long-term outcomes.