Long-term treatment outcomes of upadacitinib for Crohn's disease: a single-center retrospective study.

Background: Upadacitinib is the sole Janus kinase inhibitor approved for Crohn's disease in Japan, with its short-term efficacy already known. However, its long-term real-world outcomes remain unclear. This study aimed to evaluate its long-term continuation rates in patients with Crohn's disease and to identify predictive factors for sustained treatment. Methods: This single-center retrospective study included 41 patients with Crohn's disease treated with upadacitinib between July 2023 and April 2025. Continuation rates at 1 and 2 years defined the primary outcomes. Furthermore, predictive factors for treatment discontinuation, predictive scoring system development, upadacitinib's effects on perianal draining fistulas, endoscopic outcomes, and adverse events were the secondary outcomes. Results: The cumulative continuation rates were 67% and 63% at 1 and 2 years, respectively. In univariate analysis, factors such as age ≥ 40 years, penetrating disease behavior, prior intestinal resection, small-bowel stoma, prior exposure to ≥3 biologics, low baseline inflammation (C-reactive protein < 0.34 mg/dL and Simple Endoscopic Score for Crohn's Disease < 8), week 4 hemoglobin < 11.4 g/dL, week 4 albumin < 4.1 g/dL, and 5-aminosalicylic acid nonuse were associated with upadacitinib discontinuation. A predictive scoring system (0-8 points) demonstrated that patients with scores <3 had significantly better continuation rates than those with scores ≥3 (median: 703 vs. 341 days). Within 24 weeks of upadacitinib use, 2 of 5 patients developed perianal fistula closure. Conclusions: In Crohn's disease, upadacitinib continuation rates can be predicted using baseline patient characteristics and early biomarkers at week 4.