Efficacy and safety of inebilizumab in Asian participants with neuromyelitis optica spectrum disorder: Subgroup analyses of the N-MOmentum study

BACKGROUND

Inebilizumab, an anti-CD19 B cell-depleting antibody, reduced the risk of a neuromyelitis optica spectrum disorder (NMOSD) attack, disability worsening, magnetic resonance imaging (MRI) lesion activity, and disease-related hospitalizations in participants with NMOSD in the N-MOmentum study (NCT02200770). However, the efficacy and safety outcomes of inebilizumab specific to an Asian population were not fully reported. Therefore, subgroup analyses of the N-MOmentum study were conducted post hoc to evaluate the efficacy and safety of inebilizumab in Asian participants with NMOSD.

METHODS

The N-MOmentum study was a multicenter, double-blind, randomized, placebo-controlled phase 2/3 trial with an open-label extension period (OLP). In the subgroup analyses, data from Asian participants from the N-MOmentum study were compared with those of non-Asian participants. Eligible participants were randomly allocated (3:1) to receive 300 mg intravenous (IV) inebilizumab or placebo on Days 1 and 15. Participants who had an NMOSD attack or completed the randomized controlled period (RCP) could enter the OLP, where they received inebilizumab for ≥2 years. All participants who entered the OLP received inebilizumab 300 mg IV every 6 months.

RESULTS

Overall, 230 participants received treatment (174 received inebilizumab and 56 received placebo), of whom 47 were Asian (39 received inebilizumab and 8 received placebo). Baseline characteristics were similar between the Asian and non-Asian subgroups, except for disease duration, annualized relapse rate prior to randomization in this study, and previous maintenance therapy. In the Asian subgroup, the risk of NMOSD attacks was reduced with inebilizumab versus placebo (hazard ratio, 0.202) and the attack-free rate at 28 weeks was 82.1% with inebilizumab versus 37.5% with placebo, in the 6-month RCP. NMOSD attack rates were comparable between the Asian and non-Asian subgroups. In the Asian subgroup, the rates of Expanded Disability Status Scale worsening from baseline, active MRI lesions, and disease-related hospitalizations tended to be lower in the inebilizumab group than in the placebo group; similar results were shown in the non-Asian subgroup. For long-term efficacy and safety (RCP and OLP), the annualized adjudicated NMOSD attack rate in Asian participants treated with inebilizumab was reduced (0.096) compared with that at baseline (1.04), with a mean follow-up period of inebilizumab treatment of 3.38 years, which was consistent with the results in the non-Asian subgroup. The risk of NMOSD attack decreased with prolonged duration of treatment in both the inebilizumab/inebilizumab and placebo/inebilizumab groups in the Asian and non-Asian subgroups. The incidence of treatment-emergent adverse events (TEAEs) was similar between the Asian and non-Asian subgroups. In the Asian and non-Asian subgroups, 15.2% and 35.2% of participants, respectively, had at least one serious TEAE and/or Grade ≥3 TEAE during long-term therapy. No deaths occurred in the Asian subgroup whereas three deaths occurred in the non-Asian subgroup.

CONCLUSION

Inebilizumab reduced the risk of an NMOSD attack, progression of disability, MRI lesion activity, and disease-related hospitalizations in Asian participants with NMOSD. The efficacy of inebilizumab in reducing NMOSD attacks continued without any unexpected safety signals or concerns during long-term use in Asian participants.

Analysis of Pregnancy-Related Attacks in Neuromyelitis Optica Spectrum Disorder: A Systematic Review and Meta-Analysis

IMPORTANCE

Risk of relapse may be increased in the postpartum period of neuromyelitis optica spectrum disorder (NMOSD). Information regarding factors associated with pregnancy-related attacks is still lacking.

OBJECTIVES

To identify factors associated with pregnancy-related NMOSD attacks, investigate the integrated annualized relapse rate (ARR) and Expanded Disability Status Scale (EDSS) score in each phase of pregnancy, and summarize pregnancy outcomes and complications in patients with NMOSD.

DATA SOURCES

An electronic search was performed in the MEDLINE, PubMed in-process and non-MEDLINE, EMBASE, Web of Science, and Cochrane databases using the OvidSP search platform, updated through December 30, 2021.

STUDY SELECTION

All published and unpublished studies in English were considered, covering all patients with NMOSD with an informative pregnancy.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted the published data with a standardized procedure following MOOSE and PRISMA guidelines. The end points were calculated with the DerSimonian and Laird inverse variance (for random effects) method.

MAIN OUTCOMES AND MEASURES

The primary outcome was the rate of pregnancies with pregnancy-related NMOSD attacks, measured by risk ratios (RRs). The mean differences (MDs) in ARR and EDSS scores between each phase of pregnancy, pregnancy outcomes, and complications were defined as the secondary outcomes.

RESULTS

A total of 15 studies were analyzed, including 443 patients with NMOSD with 639 informative pregnancies. Patients receiving immunosuppressive treatment during pregnancy (RR, 0.43; 95% CI, 0.32-0.57; P < .001) and with older age at conception (RR, 0.67; 95% CI, 0.47-0.95; P = .02) had lower rates of pregnancy with pregnancy-related attacks. The increase in the ARR was highest in the first trimester after delivery compared with before pregnancy (MD, 1.28; 95% CI, 0.94-1.62; P < .001). The EDSS scores increased significantly both during pregnancy (MD, 0.44; 95% CI, 0.20-0.69; P < .001) and in the postpartum period (MD, 0.88; 95% CI, 0.51-1.26; P < .001) compared with before pregnancy.

CONCLUSIONS AND RELEVANCE

This systematic review and meta-analysis found that receiving immunosuppressive treatment during pregnancy and older age at conception were associated with reduced risk of pregnancy-related NMOSD attacks, which mostly occurred in the first trimester of the postpartum period, although more high-quality prospective studies are needed.

A Case With New-Onset Neuromyelitis Optica Spectrum Disorder Following COVID-19 mRNA BNT162b2 Vaccination

INTRODUCTION

In the midst of the coronavirus disease of 2019 pandemic, active immunization by effective vaccination gained utmost importance in terms of global health. The messenger RNA (mRNA) vaccines are novel strategies requiring clinical surveillance for adverse events.

CASE REPORT

We report a 43-year-old previously healthy female with an optic neuritis attack 24 hours following immunization with the second dose of coronavirus disease of 2019 mRNA BNT162b2 vaccine. A second transverse myelitis attack together with an elevated anti-AQP-4 antibody titer confirmed the diagnosis of neuromyelitis optica spectrum disorder.

CONCLUSION

Our case identifies the BNT162b2 vaccine as a possible trigger for neuromyelitis optica spectrum disorder. This rare and potentially coincidental event has no implications for vaccine administration practices. However, further research is needed to elucidate the effects of mRNA vaccines on humoral and cell-mediated immunity.

Neuromyelitis optica after a spinal anaesthesia with bupivacaine

We report the case of a 53-year old woman who developed a neuromyelitis optica (NMO or Devic’s syndrome) after a spinal anaesthesia with bupivacaine. To our knowledge, the use of bupivacaine in human has not been associated to neurological complications like myelitis or NMO. The patho genesis of this complication will be discussed.

[Case of NMO (neuromyelitis optica) spectum disorder triggered by interferon alpha, which involved extensive pyramidal tract lesion of the brain]

A 65-year-old woman developed left optic neuritis during the course of peg-interferon alpha (PEG-IFN-α) and ribavirin combination therapy for chronic hepatitis C. Brain T(2)W-MRI disclosed hyperintense lesions in the corpus callosum and white matter. We diagnosed neuromyelitis optica spectrum disorder (NMOSD) on the basis of anti-aquaporin-4 antibody seropositivity. PEG-IFN-α was discontinued, and she received steroid pulse therapy (intravenous high dose methylprednisolone). Two weeks later she also developed right optic neuritis. Repetitive steroid pulse therapy improved the left optic neuritis, but the upper half of the visual field of the right eye remained impaired. One month later she presented with mild dysarthria and mild left hemiparesis. Brain MRI disclosed an extensive pyramidal tract lesion from the right corona radiata to the pedunculus cerebri. This cerebral pyramidal tract lesion is associated with NMOSD. Our case corresponds to the past reports of optic neuritis or multiple sclerosis-like disease triggered by IFN-α. IFN-α may trigger NMOSD via a biological effect characteristic of Type I IFNs, a group that includes IFN-α and IFN-β.

Evidence against cellular internalization in vivo of NMO-IgG, aquaporin-4, and excitatory amino acid transporter 2 in neuromyelitis optica

Autoantibodies against astrocyte water channel aquaporin-4 (AQP4) are thought to be pathogenic in neuromyelitis optica (NMO). Prior work has suggested that a key component of NMO autoantibody (NMO-IgG) pathogenesis is internalization of AQP4 and the associated glutamate transporter EAAT2, leading to glutamate excitotoxicity. Here, we show selective endocytosis of NMO-IgG and AQP4 in transfected cell cultures, but little internalization in brain in vivo. AQP4-dependent endocytosis of NMO-IgG occurred rapidly in various AQP4-transfected cell lines, with efficient transport from early endosomes to lysosomes. Cell surface AQP4 was also reduced following NMO-IgG exposure. However, little or no internalization of NMO-IgG, AQP4, or EAAT2 was found in primary astrocyte cultures, nor was glutamate uptake affected by NMO-IgG exposure. Following injection of NMO-IgG into mouse brain, NMO-IgG binding and AQP4 expression showed a perivascular astrocyte distribution, without detectable cellular internalization over 24 h. We conclude that astrocyte endocytosis of NMO-IgG, AQP4, and EAAT2 is not a significant consequence of AQP4 autoantibody in vivo, challenging generally accepted views about NMO pathogenesis.