Lenalidomide in the Treatment of Mucosal Behçet's Syndrome

Inclusion Criteria: * Patients that can understand and voluntarily sign an informed consent document prior to the study; * Male and female subjects ≥ 18 years and ≤ 65 years of age at the time of signing the informed consent document. * Fulfilling the ICBD (International Conference on Behcet's Disease) criteria(2013); * Presented with active mucosal lesions: Subjects must have at least 1 oral ulcer within 4 weeks after the screening visit and at least 2 oral ulcers on the day of enrollment; subjects may be with or without genital ulcers and (or) skin lesions. * Refractory mucosal lesions: Subjects must experience at least 2 relapses of oral ulcers during 3 consecutive months of conventional treatment with corticosteroids and(or) immunosuppressants. * Without major organ involvement, including active gastrointestinal, ocular, nervous system, and major vessel involvement; previous major organ involvement is allowed if it occurred at least 1 year prior to the screening visit and is not active at the time of enrollment.; subjects with arthritis are permitted. Exclusion Criteria: The presence of any of the following will exclude a subject from the study enrollment. Exclusion Criteria: * Pregnant women or breastfeeding mothers, Male and female patients with recent fertility requirements. * Skin and mucosal lesions should exclude erythema multiforme, syphilis, Sweet disease, Stevens-Johnson syndrome, acne vulgaris, herpes simplex infection, periodic granulocytopenia, and acquire…