Long-term safety and effectiveness of mycophenolate mofetil in adults with lupus nephritis: a real-world study in Japan

Objectives: To assess the safety and effectiveness of mycophenolate mofetil (MMF) in Japanese adults with lupus nephritis (LN) in real-world clinical practice.

Methods: This multicentre, prospective, post-marketing surveillance study investigated the effectiveness and safety of MMF, as induction or maintenance therapy, in LN patients. Primary endpoints were adverse drug reactions (ADRs), changes in renal function from baseline, and relapse rate (RR) after 6 months in the maintenance group, estimated using the Kaplan-Meier method. Complete remission (CR) and partial remission (PR) were estimated by renal measurements.

Results: Overall, 112 patients were enrolled in the induction group and 340 in the maintenance group. Of these 452 patients, 418 were evaluable for safety and 396 for effectiveness. Eighty-three patients (19.85%) experienced ADRs, most commonly herpes zoster (3.34%) and diarrhoea (3.11%). Serious ADRs occurring in more than three patients were cytomegalovirus infections (1.43%), acute pyelonephritis (0.71%), and herpes zoster (0.71%). One patient died from herpes zoster disseminated. CR and PR were 19.54% and 44.82%, respectively, in the induction group, and 40.62% and 66.16%, respectively, in the maintenance group. RR in the maintenance group was 0.70%.

Conclusions: The tolerability of MMF is in line with that reported in other studies. Since the average dose of MMF was <1.5 g/day, research into the optimal dose for achieving effectiveness is required.