Eculizumab Lowers Relapse Risk in Neuromyelitis Optica Spectrum Disorder After Prior Rituximab Treatment

The risk of adjudicated relapse is significantly lower with eculizumab compared with placebo among patients with neuromyelitis optica spectrum disorder (NMSOD) who had previously received rituximab, a monoclonal antibody, according to study results presented at the 2021 Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC), held October 25-28, 2021 in Orlando, Florida.

In a previous trial, PREVENT, eculizumab was associated with a reduced relapse risk compared with placebo and was well tolerated among patients with NMSOD. A total of 46 patients from both the eculizumab group and the placebo group had received prior treatment with rituximab. The efficacy and safety profile of eculizumab in the PREVENT trial for patients previously treated with rituximab was not explored. The objective of the current study was to observe how effective and safe eculizumab is in this specific patient population when it comes to reducing the risk of adjudicated relapse. 

Researchers conducted a post-hoc descriptive analysis of patients with aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder from the PREVENT trial. The participants had received any previous rituximab treatment (within the previous year regarding adverse events [AEs]) more than 3 months before randomization.

A total of 46 patients—26/96 in the eculizumab group and 20/47 in the placebo group—had previously received rituximab. The participants were administered eculizumab as a maintenance dose, 1200 mg/2 weeks, or placebo with or without concomitant immunosuppressive treatment, except rituximab/mitoxantrone.

The prior-rituximab subgroup had similar baseline characteristics as those in the overall PREVENT population, except the subgroup included a lower proportion of Asian patients (10.9% vs 36.4% in total PREVENT) and a higher percentage of patients from the Americas (58.7% vs 30.8%, respectively). In the subgroup, the median times from the last dose of rituximab to meningococcal vaccination and to the first dose of treatment were 31.7 and 38.7 weeks, respectively.

Among patients in the eculizumab group, adjudicated relapses were observed in 1/26 participants (3.8%), compared with 7/20 patients (35.0%) in the placebo group (hazard ratio, 0.093; 95% CI, 0.011-0.755; P =.0055).

AE rates were 1025.8 and 1029.1 events/100 patient-years (100% of patients) for the eculizumab and placebo groups, respectively, and the rates of serious AEs were 46.9 and 66.0 events/100 patient-years (38.9% and 47.1% of patients), respectively.

Serious infections were observed in 2/18 patients (11.1%) in the eculizumab group and in 2/17 patients (11.8%) in the placebo group.

“In patients in PREVENT who had previously received rituximab, the risk of adjudicated relapse was significantly lower with eculizumab than with placebo. Rates of serious infections were similarly low with eculizumab and placebo,” the researchers concluded.

Disclosure: Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Levy M, Berthele A, Kim HJ, et al. Efficacy and safety of eculizumab in patients with neuromyelitis optica spectrum disorder previously treated with rituximab: findings from PREVENT. Presented at: CMSC 2021 Annual Meeting; October 25-28, 2021; Orlando, Florida. Abstract DMT48.