Clardy, Stacey

Importance Myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD) lacks proven relapse-preventive therapies. While clinical trials are ongoing, safety data may be limited and approved drugs are costly. Studies of interleukin 6 receptor blocker (IL-6RB) in MOGAD are limited by small numbers and no comparative studies, contributing to low use. Objective To evaluate the impact of IL-6RB therapy on relapse rates in MOGAD and compare relapse frequency with intravenous immunoglobulin (IVIG). Design, Setting, and Participants This international, multicenter, retrospective cohort study (January 1, 2015, through December 31, 2025) included a historical IVIG-treated cohort of varying doses. The study took place across sites in North and South America (US, Canada, Mexico, Argentina, Brazil, Chile, Colombia, and Peru). Patients with MOGAD (n = 116, no excluded patients) who received at least 1 dose of an IL-6RB were included. These data were analyzed in January 2026. Exposures Tocilizumab or satralizumab. Main Outcomes and Measures Annualized relapse rate (ARR) during IL-6RB therapy, time to next relapse after treatment initiation, and adverse events. Outcomes were compared with the IVIG cohort using inverse probability of treatment weighting (IPTW) adjusted for age, sex, prior ARR, and concomitant therapies. Results A total of 116 patients with MOGAD (89% relapsing) receiving IL-6RB (tocilizumab, 104 [90%] and satralizumab, 12 [10%]) were included; overall, 60.3% were female, 39.7% were male, and 18% were younger than 18 years. The median (IQR) IL-6RB treatment follow-up was 1.4 (0.7-2.5) years and 23 relapses occurred during 241.8 person-years of IL-6RB therapy. The ARR decreased from 0.64 (95% CI, 0.58-0.70) for relapsing MOGAD before IL-6RB to 0.09 (95% CI, 0.06-0.14) during IL-6RB treatment (incidence rate ratio, 0.08; 95% CI, 0.04-0.16). Adverse events occurred in 58 patients (50%), most commonly mild infections, although 10 (9%) had severe infections. In the IVIG cohort (n = 59), 30 relapses occurred over 133.8 person-years (ARR, 0.22; 95% CI, 0.15-0.32). After IPTW, IL-6RB was associated with a lower hazard ratio (HR) than the group who underwent IVIG therapy less than 1 g/kg every 4 weeks (HR, 4.5; 95% CI, 2.0-9.8), with no significant difference vs the group who underwent IVIG 1 g/kg or more every 4 weeks (HR, 2.0; 95% CI, 0.8-4.5). Conclusions and Relevance In this multicenter observational cohort, IL-6RB use in MOGAD was associated with low relapse rates and a favorable safety profile, though severe infections occurred occasionally. Relapse rates were lower than the group who underwent IVIG less than 1 g/kg every 4 weeks but not significantly different from the group who underwent IVIG 1 g/kg or more every 4 weeks. This supports IL-6RB as a potential relapse-prevention therapy in MOGAD; the wide availability and relative affordability of tocilizumab may enable broad global use.

ABSTRACT Objective The optimal treatment for neurosarcoidosis myelitis is uncertain. We characterize incident neurosarcoidosis myelitis and assess treatment response by MRI and clinical scales. Methods Incident probable or definite neurosarcoidosis myelitis in adults was retrospectively identified from 13 academic medical centers. Cases were analyzed by initial treatment. The primary outcome was T1 post‐contrast gadolinium enhancement resolution at 6 months post‐treatment. Secondary outcomes were changes in modified Rankin scale (mRS) and Expanded Disability Status Scale (EDSS) from nadir to final follow‐up. Results Two hundred two patients were identified (median diagnosis age: 47 years (IQR 39–55); male: female 1.3:1). Median nadir mRS and EDSS were 2 (IQR 2–3) and 4 (IQR 2.5–6). At initial treatment, 129 (63.9%) received prolonged corticosteroids ≥ 4 weeks (group A 1 ), 36 (17.8%) received corticosteroids < 4 weeks (B 1 ), 21 (10.4%) received corticosteroids plus sarcoidosis‐directed immunosuppressant (E), and 16 (7.9%) received corticosteroids plus non‐sarcoidosis‐directed agents (F). In 167 cases with sufficient imaging, there were no significant differences in contrast enhancement resolution at 6 months (A 1 27/106 (25.5%), B 1 9/28 (32.1%), E 5/19 (26.3%), F 5/14 (35.7%); Fisher's exact p = 0.76). There were no significant differences in changes in mRS or EDSS among treatment groups (Kruskal–Wallis p = 0.69 and 0.63, respectively) after median follow‐up of 46.5 months (IQR 18–91.3). Interpretation Different initial immunosuppression strategies did not correlate with MRI contrast enhancement resolution at 6 months or clinical scales (mRS, EDSS). However, conclusions are limited by retrospective design, imbalanced cohorts, and insensitivity of binary MRI outcomes and available clinical scales for treatment response in neurosarcoidosis.