Long-term efficacy of mycophenolate mofetil in myelin oligodendrocyte glycoprotein antibody-associated disorders: A prospective study

Abstract

Objective: To investigate whether the use of mycophenolate mofetil (MMF) could reduce the relapse risk in patients with myelin oligodendrocyte glycoprotein (MOG)-immunoglobulin G (IgG)-associated disorders (MOGADs).

Methods: This prospective observational cohort study included patients with MOGAD at Peking Union Medical College Hospital between January 1, 2017, and April 30, 2019. The patients were divided into 2 groups: those with (MMF+) or without (MMF-) MMF therapy. The primary outcome was relapse at follow-up. We used Cox proportional hazards models to calculate hazard ratios (HRs) for relapse.

Results: Seventy-nine patients were included in our MOG cohort. Fifty (63.3%) were adults at index date, and 47 (59.5%) were women. Fifty-four (68.4%) were in the MMF+ group, and 25 (31.6%) were in the MMF- group. Clinical and demographic factors, MOG-IgG titer, and follow-up time (median, 472.5 days for MMF+, 261.0 days for MMF-) were comparable between the groups. Relapse rates were 7.4% (4/54) in the MMF+ group and 44.0% (11/25) in the MMF- group. Of all potential confounders, only the use of MMF was associated with reduced risk of relapse. The HR for relapse among patients in the MMF+ group was 0.14 (95% CI, 0.05-0.45) and was 0.08 (95% CI, 0.02-0.28) in a model adjusted for age, sex, disease course, and MOG-IgG titer. MMF therapy also remained associated with a reduced relapse risk in sensitivity analyses. Only one patient (1.9%) discontinued MMF therapy because of adverse effect.

Conclusions: These findings provide a clinical evidence that MMF immunosuppression therapy may prevent relapse in patients with MOGAD.

Classification of evidence: This study provides class IV evidence that for patients with MOGAD, MMF reduces relapse risk.

Figure 1. Selection of patients

AZA = azathioprine; MMF = mycophenolate mofetil; MOG-IgG = myelin oligodendrocyte glycoprotein immunoglobulin G.

Figure 2. Kaplan-Meier curves showing the probability of survival free of relapse in patients with an MOG-IgG-associated disorder

Log-rank test: p < 0.001. Tick marks indicate censored patients. MMF = mycophenolate mofetil; MOG = myelin oligodendrocyte glycoprotein.

Figure 3. HRs for relapse in subgroup analyses

(A) Other includes 3 patients who were pregnant/lactating and 7 with fatigue/poor sleep/tension. (B) Other includes 9 with cerebellum/brain stem involvement, 4 with optic neuritis and cerebrum involvement, 3 with myelitis and cerebrum involvement, 2 with optic neuritis and myelitis, 2 with cerebellum/brain stem and cerebrum involvement, and 2 with meningitis. (C) 0: patients with 1 attack before the index date; <3.0: patients with ≥2 attacks before the index date and ARR <3.0; ≥3.0: patients with ≥2 attacks before the index date and ARR ≥3.0. (D) Two missing datapoints. ARR = annualized relapse rate; HR = hazard ratio; MMF = mycophenolate mofetil; MOG = myelin oligodendrocyte glycoprotein.