Upadacitinib for Refractory Behcet's Syndrome

Inclusion Criteria: * • Male or female aged 18-70 years at time of screening. * Diagnosis of Behcet's syndrome (according to the International Criteria for Behçet's Disease) for ≥3 months before screening. * Active Behcet's syndrome at time of screening (BDCAF≥2). * Resistant to glucocorticoids, at least two traditional immunosuppressants (one of which must have been cyclophosphamide or mycophenolate mofetil) or biological agents (one of which must have been a TNF-α inhibitor or a JAK inhibitor) for at least 6 months. * Given their written informed consent to participate in the trial and expected to be able to adhere to the study visit schedule and other protocol requirements. Exclusion Criteria: * High-dose glucocorticoid (\>1mg/kg/d) usage within 1 month. * Severe comorbidities: including heart failure (≥ grade III NYHA), renal insufficiency (creatinine clearance ≤30 ml/min), hepatic insufficiency (serum ALT or AST \>3 times the ULN, or total bilirubin \>ULN for the central laboratory conducting the test). Other severe, progressive or uncontrolled hematologic, gastrointestinal, endocrine, pulmonary, cardiac, neurologic, or cerebral disease (including demyelinating diseases such as multiple sclerosis). * Known allergies, hypersensitivity, or intolerance to Baricitinib or its excipients. * Had a severe infection (including, but not limited to hepatitis, pneumonia, sepsis, or pyelonephritis); had been hospitalized for an infection; or had been treated with IV antib…