Mycophenolate mofetil (MMF) is used off-label for systemic lupus erythematosus (SLE) and systemic vasculitis. The study aim was to investigate clinical use and treatment results with MMF in patients with SLE and systemic vasculitis. This study included patients with SLE or systemic vasculitis with ongoing or previous MMF treatment. Data on treatment outcome were obtained through medical record reviews. A total of 135 of 648 (21%) patients with SLE and 43 of 455 (9%) patients with systemic vasculitis had ongoing or previous MMF treatment. Among SLE patients, the most common organ manifestation at baseline (treatment start) was renal involvement (50%). Most of the systemic vasculitis patients had Wegener's granulomatosis (GPA) (65%). Median dose of MMF was 2000 mg/day. Glucocorticoid (GC) doses were significantly reduced during MMF treatment from 21.7 mg/day at baseline to 8.3 mg/day at 12 months (p < 0.05). Forty-six percent of the patients were good responders after 12 months. The most common adverse events (AES) leading to discontinuation were side effects in the gastrointestinal tract (40%) and general side effects (30%). "Survival-on-drug" analysis suggested that 40% of the patients remained on long-term MMF treatment. In conclusion, MMF was used in 21% of the SLE patients and 9% of the systemic vasculitis patients. MMF appeared to be effective with a reasonable survival-on-drug and a GC-sparing effect.
Keywords: Systemic lupus erythematosus; mycophenolate mofetil; systemic vasculitis.