Abstract
OBJECTIVE: This study aimed to evaluate the efficacy and safety of upadacitinib in patients with refractory Behcet’s syndrome (BS). METHODS: A multicentre, single-arm trial was conducted from February 2023 to August 2025. Eligible patients had BS refractory to at least two immunosuppressive agents or one targeted therapy for a minimum of 6 months. Participants discontinued previous targeted therapies and received upadacitinib 15 mg/day for up to 48 weeks, in addition to their ongoing glucocorticoid and immunosuppressant regimens. Clinical features, inflammatory markers, imaging findings, and treatment data were collected throughout follow-up. The primary endpoint was the overall response rate (ORR; complete response [CR] plus partial response [PR]) at 24 weeks. RESULTS: Twenty-seven patients (16 male; median age 36 years) were enrolled, with a median baseline BDCAF score of 4 (range: 2–7). Affected systems included the mucocutaneous, articular, gastrointestinal, cardiovascular, and ocular systems. The ORR at 24 weeks was 85.2% (23/27), comprising 16 CRs and 7 PRs. Significant reductions were observed in median BDCAF scores, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and glucocorticoid dosage by week 24. Among the 23 patients who achieved remission at week 24, median CRP and ESR levels at 48 weeks were significantly lower than those at 24 weeks. For clinical responses across different systems, CR was achieved in 3 (100.0%) with cardiovascular involvement, 5 (83.3%) with ocular symptoms, 10 (76.9%) with gastrointestinal involvement, 16 (59.3%) patients with mucocutaneous symptoms, and 1 (16.7%) with articular involvement at 24 weeks. Three patients experienced relapse during the follow-up. No serious adverse events were reported. CONCLUSION: Upadacitinib represents a potential therapeutic option for patients with refractory BS. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13075-026-03778-x.