Five-years drug survival of mycophenolate mofetil therapy in patients with systemic lupus erythematosus. comparison between renal and non-renal involvement

Objective: The EULAR recommendations underline the use of MMF for Lupus Nephritis (LN) but also for the treatment of moderate/severe non-renal manifestations (NLN). This study aims at evaluating the 5-years drug retention rate (DRR) of MMF in a SLE cohort in a real-life scenario. Secondly, we investigated the MMF influence to control chronic damage progression. Methods: We performed a longitudinal study including all the SLE patients starting MMF in our Lupus Clinic (from 2008 to 2020). The DRR was estimated using the Kaplan-Meier method. Results: We evaluated 162 SLE patients (M/F 22/140). The most frequent indications for prescribing MMF were LN (101 patients, 62.3%) and musculoskeletal manifestations (39, 24.1%) followed by NPSLE (10, 6.2%) and other manifestations (12, 7.4%). We registered a median treatment duration of 30 months (IQR 55). At 60 months follow-up we observed a DRR of 61.1% for LN patients, which was similar to that registered for patients without renal involvement (60.5%). The DRR was higher in the subgroup of patients with joint involvement (75.4%, p non-significant). During the overall observation period, 92 patients (59.2%) discontinued MMF. The main cause of withdrawal was the achievement of remission, observed in 20 patients (21.7%). Moreover, MMF resulted able to control chronic damage progression, as demonstrated by the lack of significant increase in the median SDI values (baseline: 0.6, IQR 1; last: 0.93, IQR 1). Conclusions: Our finding suggested that MMF is a safe and effective drug for SLE manifestation other than LN, especially for joint involvement. Moreover, it was able to reduce the chronic damage progression.