60 active IgG4-RD patients with internal organ involvement are enrolled in this study and accept the combination treatment of glucocorticoids and mycophenolate mofetil in remission induction period (6 months), during which glucocorticoids are tapered regularly and discontinued in 3 months. During remission maintenance period, pateints are randomly divided into two groups at a 1:1 ratio: patients in group I are treated with low dose mycophenolate mofetil (0.5-1g/day) and patients in group Ⅱ accept the treatment of leflunomide (10-20 mg/day). Patients in two groups will be followed up for another 6 months, and clinical evaluations, laboratory tests, image examinations and IgG4-RD responder index (RI) will be recorded during follow up. The primary endpoint is the difference of relapse rate between two groups at 12 months. The secondary endpoints are relapse time, response rate and side effects.
This study has been designed as a 12-month, open-label randomized controlled clinical trial. The study aims to compare the efficacy and safety of two treatment strategies in active IgG4-RD patients with internal organ involvement during maintenance remission period: low dose mycophenolate mofetil group and leflunomide group.