Efficacy and safety of high-dose of mycophenolate mofetil compared with cyclophosphamide pulse therapy as induction therapy in Japanese patients with proliferative lupus nephritis

To clarify the effectiveness and safety of induction therapy with mycophenolate mofetil (MMF) in patients with lupus nephritis (LN).Patients with LN administered MMF (n = 35) or intravenous cyclophosphamide pulse therapy (IVCY) (n = 25) plus high-dose corticosteroids between July 2015 and June 2020 were included. MMF was increased from 2 to 3 g/day, with no adverse events (AEs). The primary endpoint was the 6 month renal remission rate. Secondary endpoints were retention rate and AEs.There were no significant differences in age, sex, disease duration, renal histological type, SLE disease activity index, and urine protein creatinine ratio between the two groups. Twenty-six patients (74%) continued with MMF therapy, whereas 12 (48%) completed six IVCY courses. The retention rate was significantly higher in the MMF than in the IVCY group (p = 0.048). Twenty-four and 14 patients in MMF and IVCY groups, respectively, achieved renal remission with insignificant differences. Grade 3 or higher AEs were observed in 8 and 14 patients in the MMF and IVCY groups, respectively (p = 0.014).The efficacy of high-dose MMF was comparable to that of IVCY in Japanese patients with proliferative LN, with fewer AEs and a higher retention rate than IVCY, suggesting the high tolerability of MMF.