Baricitinib in the Treatment of Intestinal Behçet's Syndrome

Inclusion Criteria:

1. Refer to the consensus on the diagnosis and treatment of intestinal Behçet'ssyndrome in China: Patients who meet the 2013 International Criteria for Behçet'sDisease (ICBD) and have typical Behçet's syndrome-related intestinal ulcersconfirmed by colonoscopy, or patients diagnosed according to the criteria forBehçet's syndrome established by the Korean Behçet's Disease Collaborative Group in 2009;

2. Patients have a DAIBD score ≥ 40 points or intestinal symptom score ≥ 3 points atbaseline;

3. Endoscopic examination conducted within 60 days before inclusion suggests activeintestinal ulcers;

4. Patients who have been treated with medium to high-dose steroids (prednisoloneequivalent of 0.5-1 mg/kg/day) for more than 1 month continuously, or anyimmunomodulator/Immunosuppressants for more than 3 months regularly or biologics formore than 2 months, as judged by the doctor to be treatment failure or intolerance;

5. Currently steroid dose ≤ 30 mg prednisolone equivalent, stabilized for ≥ 2 weeks,and/or stabilized immunomodulator dose for ≥ 4 weeks;

6. Understanding the research process, voluntary participation, and signing of informedconsent.

Exclusion Criteria:

1. Diagnosis of other diseases such as Crohn's disease, ulcerative colitis, lymphoma,etc.;

2. Other active organ damage related to BS requires intensified immunosuppressivetherapy, including aneurysms, uveitis, and substantial involvement of the centralnervous system; skin lesions and joint involvement can be included;

3. Severe organ dysfunction including ALT, AST, TBIL levels exceeding twice the upperlimit of normal, creatinine levels exceeding 1.5 times the upper limit of normal,white blood cell count < 3×10^9/L, ANC < 2×10^9/L, hemoglobin < 80g/L, platelets < 100×10^9/L;

4. Active infections such as active tuberculosis, active hepatitis B or C, syphilis,chronic Epstein-Barr virus infection, HIV infection, sustained or severe bacterialor viral infections, and history of severe herpes zoster;

5. Patients with latent tuberculosis must undergo ≥3 weeks of prophylacticanti-tuberculosis treatment before inclusion;

6. Primary immunodeficiency disease;

7. History of cancer, or endoscopic intestinal histopathology indicatingintraepithelial neoplasia or malignancy, or presence of other malignancies;

8. Patients who did not respond to infliximab treatment for primary refractory BS (patients with secondary failure, intolerance, or allergy to infliximab should beincluded);

9. Patients treated with biologics/small molecule targeting therapies within 5half-lives (including use of tofacitinib within 10 days, etanercept within 4 weeks,infliximab within 8 weeks, golimumab, certolizumab, abatacept, and tocilizumabwithin 10 weeks, ustekinumab within 6 months);

10. Patients with prior use of baricitinib or ADA;

11. Complications of intestinal BS such as symptomatic stenosis, short bowel syndrome,intestinal fistula, or suspected intra-abdominal abscess; potential need for surgeryor situations not conducive to DAIBD and efficacy assessment; any form of intestinalresection or other abdominal surgery within 6 months before baseline; presence of afunctioning (i.e., patent) stoma or ostomy;

12. Patients requiring parenteral nutrition due to disease severity;

13. Pregnant, lactating, or planning pregnancy soon;

14. Patients unwilling or unable to comply with regular visits;

15. History of severe thrombotic events or chronic cardiovascular events.