To report primary and key secondary efficacy and safety results of the Phase 3 METEOROID (NCT05271409) study investigating satralizumab in patients with MOGAD.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a demyelinating disease in which attacks can result in prominent neurological and visual disability, yet proven attack-prevention treatments are lacking. Interleukin-6 (IL-6) has a key role in MOGAD pathogenesis. Satralizumab blocks the IL-6 receptor.

METEOROID, a randomized, double-blind (DB), placebo-controlled study enrolled patients (≥12 years) with relapsing MOGAD (≥1 relapse in the last 12 months or ≥2 attacks in the last 24 months). Patients were randomized 1:1 to satralizumab or placebo ± concomitant immunosuppressive therapy (IST). Satralizumab was administered subcutaneously at Weeks 0, 2, 4 and Q4-weeks thereafter. The primary endpoint was time to first relapse, adjudicated by an independent committee. Key secondary endpoints evaluated relapse rate, active MRI lesions, need for rescue therapy and rate of hospitalizations. Safety was assessed.

Overall, 132 patients randomly assigned to satralizumab (n=68) or placebo (n=64). Satralizumab treatment prolonged the time to first relapse versus placebo resulting in a 68% reduction in the risk of a new MOGAD relapse (hazard ratio: 0.32; 95% confidence interval: 0.15–0.70; p=0.0025). The proportion of relapse-free patients at 48 weeks was 87.3% (satralizumab) versus 66.5% (placebo).

Consistency in efficacy was observed across subgroups. Key secondary endpoints of annualized relapse rate, annualized rate of active lesions and proportion of participants receiving rescue therapy were also statistically significant, with 66.3%, 78.5% and 72.5% risk-reductions, respectively, with satralizumab treatment. The rates of adverse events (AEs) and infections were comparable between groups; rates of serious AEs were low and unrelated to treatment. Treatment discontinuation rates were low.

Satralizumab significantly reduced the risk of attack in patients with relapsing MOGAD compared with placebo, with a favorable safety profile.