Comparison of the efficacy and safety of leflunomide versus mycophenolate mofetil in treating IgG4-related disease: a retrospective cohort study

Objective Combination therapy of glucocorticoids (GCs) plus leflunomide (LEF) and GCs plus mycophenolate mofetil (MMF) was reported to have good efficacy and safety in the management of IgG4-RD. However, studies comparing the efficacy and safety of these two combination therapies were unavailable. Herein, this study aimed to compare the efficacy and safety of GCs plus LEF and GCs plus MMF in treating IgG4-RD. Methods This study included 130 newly diagnosed IgG4-RD patients who received the therapy of GCs plus LEF (group I) and GCs plus MMF (group II). Clinical data at baseline and after treatment, treatment response, relapse rate, and adverse effects were recorded and analyzed. Results Patients in both groups responded well to the treatment in the 1st-month follow-up, and 100% of patients achieved treatment response. However, at the 6th and 12th-month follow-up, the total response rate of group II was higher than that in group I (75.6 vs. 53.7%, p = 0.038 and 85.4% vs. 61.0%, p = 0.013, respectively). In addition, the duration of disease remission in group II was longer than that in group I (9 (6–9) vs. 6 (6–6) months, p = 0.014). Moreover, more patients in group I had adverse effects compared with group II (36.6 vs. 7.3%, p < 0.01); and the most common adverse events of LEF were rash (12.2%) and elevation of liver enzymes (9.8%). Conclusion The combination therapy of GCs plus low-dose MMF had better efficacy and safety in the management of IgG4-RD compared with the therapy of GCs plus LEF. Key points • This is the first study comparing the efficacy and safety of GCs plus LEF/MMF against IgG4-RD. • GCs plus MMF had better efficacy and safety in the management of IgG4-RD. • This study provides physicians with decision-making advice in choosing a treatment strategy for IgG4-RD.