Biologic Therapy in Refractory Non-Multiple Sclerosis Optic Neuritis Isolated or Associated to Immune-Mediated Inflammatory Diseases. A Multicenter Study.

We aimed to assess the efficacy of biologic therapy in refractory non-Multiple Sclerosis (MS) Optic Neuritis (ON), a condition more infrequent, chronic and severe than MS ON. This was an open-label multicenter study of patients with non-MS ON refractory to systemic corticosteroids and at least one conventional immunosuppressive drug. The main outcomes were Best Corrected Visual Acuity (BCVA) and both Macular Thickness (MT) and Retinal Nerve Fiber Layer (RNFL) using Optical Coherence Tomography (OCT). These outcome variables were assessed at baseline, 1 week, and 1, 3, 6 and 12 months after biologic therapy initiation. Remission was defined as the absence of ON symptoms and signs that lasted longer than 24 h, with or without an associated new lesion on magnetic resonance imaging with gadolinium contrast agents for at least 3 months. We studied 19 patients (11 women/8 men; mean age, 34.8 ± 13.9 years). The underlying diseases were Bechet's disease (n = 5), neuromyelitis optica (n = 3), systemic lupus erythematosus (n = 2), sarcoidosis (n = 1), relapsing polychondritis (n = 1) and anti-neutrophil cytoplasmic antibody -associated vasculitis (n = 1). It was idiopathic in 6 patients. The first biologic agent used in each patient was: adalimumab (n = 6), rituximab (n = 6), infliximab (n = 5) and tocilizumab (n = 2). A second immunosuppressive drug was simultaneously used in 11 patients: methotrexate (n = 11), azathioprine (n = 2), mycophenolate mofetil (n = 1) and hydroxychloroquine (n = 1). Improvement of the main outcomes was observed after 1 year of therapy when compared with baseline data: mean ± SD BCVA (0.8 ± 0.3 LogMAR vs. 0.6 ± 0.3 LogMAR; p = 0.03), mean ± SD RNFL (190.5 ± 175.4 µm vs. 183.4 ± 139.5 µm; p = 0.02), mean ± SD MT (270.7 ± 23.2 µm vs. 369.6 ± 137.4 µm; p = 0.03). Besides, the median (IQR) prednisone-dose was also reduced from 40 (10-61.5) mg/day at baseline to. 2.5 (0-5) mg/day after one year of follow-up; p = 0.001. After a mean ± SD follow-up of 35 months, 15 patients (78.9%) achieved ocular remission, and 2 (10.5%) experienced severe adverse events. Biologic therapy is effective in patients with refractory non-MS ON.