Abstract Background While upadacitinib (UPA) has been approved for the treatment of patients with moderate to severe Crohn’s disease in China, there is still a lack of real world evidence focusing specifically on those with perianal fistulizing Crohn’s disease (PFCD). This study aims to evaluate the effectiveness and safety of UPA in the management of PFCD in Chinese patients. Methods This study retrospectively enrolled patients with PFCD who were treated with UPA at the IBD Center of the Affiliated Hospital of Nanjing University of Chinese Medicine from July 2023 to May 2025. The primary outcome was closure of fistulas (absence of drainage with gentle finger compression on examination). Secondary outcomes included clinical response Harvey–Bradshaw Index (HBI) ≤ 4 or at least 50% improvement from baseline, clinical remission (HBI≤ 4), radiological remission (the absence of high-signal tracts on T2-weighted scans), and adverse events during the treatment. Logistic regression was used to identify factors associated with the closure of fistula at week 12. Results A total of 49 patients were enrolled, with a male-to-female ratio of 2.5:1 and a median follow-up period of 9 (5, 15) months. 38.8% (19/49), 56.7% (17/30), and 63.6% (14/22) of patients were in closure of fistulizing at 12, 26, and 52 weeks during UPA treatment respectively. The clinical response and clinical remission rates at 12, 26, and 52 weeks were 87.8% (43/49) and 85.7% (42/49); 86.7% (26/30) and 86.7% (26/30); and 95.5% (21/22) and 95.5% (21/22), respectively. Complete radiological remission was achieved in 18.8% (3/16), 23.1% (3/13), and 33.3% (3/9) of patients at 12, 26, and 52 weeks. During the 52-week period, 44.9% of patients experienced at least one adverse event. A total of 28 adverse events were reported, with acne, infections, liver dysfunction, dyslipidemia, and anemia were the most common ones. One patient discontinued treatment due to severe liver dysfunction, and two switched to another treatment due to uncontrolled disease. No death was reported. Pre-treatment use of UST was the independent factor associated with closure of external openings (OR: 223.866, 95% CI: 1.147–43685.976, p = 0.044). Conclusion This study represents the largest single-center retrospective investigation of UPA in China. These findings suggest that UPA appear effective, achieving remission in perianal fistula patients, with generally favorable safety. Conflict of interest: Ms. Han, Shuangshuang: No conflict of interest Chen, Qi: No conflict of interest Xiang, Yu: No conflict of interest Guo, Wenjie: No conflict of interest Gong, Yuxia: No conflict of interest Yang, Bolin: No conflict of interest Zhu, Weiming: No conflict of interest
Han et al. (2026) studied this question.