Optimal management of neuromyelitis optica spectrum disorder with aquaporin-4 antibody by oral prednisolone maintenance therapy

Anti-IL-6 receptor antibody suppresses onset of paralytic symptoms in AQP4 peptide-immunized mice without lowering bone strength or mineral density

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease characterized by the production of autoantibodies against aquaporin-4 (AQP4). Treatment with prednisolone (PSL) or anti-IL-6 receptor (IL-6R) antibody can reduce the frequency of relapse in patients with AQP4 antibody-positive NMOSD. We previously established a mouse model of paralysis induced by intradermal immunization with AQP4 peptide. In this study, we investigated the effects of PSL and anti-IL-6R antibody treatment on paralysis and on bone fragility in this NMOSD mouse model. Prednisolone and anti-IL-6R antibody treatment each suppressed the clinical scores and incidence of paralytic symptoms in AQP4 peptide-immunized mice. High-PSL treatment induced thinning of cortical bone and reduction of tissue mineral density in the femoral shaft and a decrease in femoral bone strength, although it increased bone volume/tissue volume in the trabecular bone of the distal femur. In contrast, anti-IL-6R treatment showed no significant differences in bone strength or cortical thickness compared to the non-immunized naive group. Bone morphometric analysis showed that high-PSL treatment reduced the bone formation rate in both cortical and trabecular bone, with a predominance of bone resorption, whereas anti-IL-6R treatment demonstrated no notable effect on bone metabolism. These results suggest that anti-IL-6R antibody can prevent the development of paralytic symptoms in AQP4 peptide-immunized mice without reducing bone strength.

Effectiveness and safety of glucocorticoids bridging rituximab in neuromyelitis spectrum disorder

BACKGROUND

Anti-CD20 monoclonal antibody rituximab have been widely used to prevent relapses in patients with neuromyelitis optica spectrum disorder (NMOSD), but data on early use of oral prednisone overlapping with rituximab for effective reduction of relapses are limited. In this study, we evaluated the long-term efficacy of oral prednisone bridging rituximab therapy in NMOSD patients with anti-aquaporin-4 antibody (AQP4-IgG).

METHODS

We collected the medications and disease activities in patients with AQP4-IgG+ NMOSD patients in this retrospective study. Time to first relapse was evaluated after starting stable doses of prednisone and/or initiating rituximab. We compared the efficacy and safety of different doses of prednisone with sequential rituximab treatment in NMOSD.

RESULTS

211 patients fulfilled the inclusion criteria for the study, including 91 patients who were treated with prednisone monotherapy and 120 patients who were treated with prednisone bridging rituximab. In total, 59.3% (54/91) of patients in the prednisone monotherapy group experienced new relapses. The proportions of patients with relapses were different in the subgroups of prednisone monotherapy, with 100% (23/23) in the group of dose ≤ 5mg/d, 64.1% (25/39) in the group of doses 7.5-10mg/d, and 20.7% (6/29) in the group of dose ≥ 12.5mg/d. 24.2% (29/120) of patients in the prednisone bridging rituximab group experienced relapses. Bridging rituximab regimen significantly reduced the risk of relapses compared to prednisone monotherapy (hazard ratio: 0.24, 95% CI: 0.15-0.38, p < 0.0001). Patients with prolonged usage of prednisone tapering (6-12 months) had a significant reduction in the relapse risk compared to those with prednisone tapering 3-6 months (hazard ratio: 0.3119, 95% CI: 0.09125-1.066, p = 0.0264). The most common adverse events were hyperlipidemia in the prednisone monotherapy group (17.6%) and infections in the prednisone bridging rituximab group (25.8%).

CONCLUSIONS

Prednisone bridging rituximab therapy is associated with the reduced relapse risk in patients with AQP4-IgG+ NMOSD, especially when the bridging time is over 6 months.

Usage status of biologics for the chronic treatment of optic neuritis in neuromyelitis optica spectrum disorders in Japan

PURPOSE

To investigate the usage status of biologics for the chronic treatment of optic neuritis including neuromyelitis optica spectrum disorders in Japan.

DESIGN

Multicenter retrospective case series.

METHODS

Patients diagnosed with anti-aquaporin 4 antibody (AQP4-Ab) positive optic neuritis and had been initiated on biologics (satralizumab, eculizumab, and inebilizumab) between January 2020 and August 2022 were identified at 30 facilities in Japan. These patients were investigated regarding changes in oral steroid doses, optic neuritis relapse, and adverse events after initiation of biologics.

RESULTS

Eighty-eight patients with AQP4-Ab positive optic neuritis initiated on biologics were included. Satralizumab was the most common biologic used (79 patients), followed by eculizumab (6 patients) and inebilizumab (3 patients). In the satralizumab group, during the observation period (10.0±7.0 months) until February 2023, the oral steroid dose was reduced significantly from 13.8 ± 8.6 mg/day at the time of initiation to 5.3 ± 4.8 mg/day (p < 0.001). No relapse of optic neuritis was observed in 76 of 79 patients (96.2%) after initiation of satralizumab. Furthermore, in 15 patients who succeeded in discontinuing steroids during 8.5 ± 5.8 months after initiation of satralizumab, no relapse of optic neuritis was observed throughout the observation period. Adverse events occurred in 7 patients with satralizumab and 2 patients with eculizumab, but no serious infections were observed.

CONCLUSIONS

Satralizumab was the most commonly used biologic for AQP4-Ab positive optic neuritis in Japan. This study demonstrates the efficacy and safety of satralizumab in preventing the relapse of optic neuritis.

The real-world impact of biologics for NMOSD: A retrospective single-center study compared with natural course and conventional treatments in Japanese

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD), a central nervous system inflammatory disease associated with aquaporin-4 immunoglobulin G (AQP4-IgG), is conventionally treated with oral steroids and immunosuppressants (IS) in Japan. Several biologics which show great efficacy in the clinical trials have been developed recently. However, studies on their efficacy, especially those comparing them with conventional treatments in real-world situations are lacking.

OBJECTIVE

Here, we conducted a single-center retrospective cohort study in Japan comparing the efficacy of biologics, over conventional drugs, in treating AQP4-IgG-positive NMOSD.

METHODS

We extracted the medical history of patients with AQP4-IgG-positive NMOSD who visited the Tohoku University Hospital between 2000 and 2023, from the hospital patient database. All patients were diagnosed according to the international consensus diagnostic criteria for NMOSD 2015. We then classified the disease duration of each patient into four periods based on their prescription history as: no-treatment, prednisolone monotherapy (PSL-mono), immunosuppressants (IS) treatment, and biologics (Bio) treatment. Subsequently, the efficacy of Bio treatment, over the conventional treatment, in alleviating AQP4-IgG-positive NMOSD was estimated. We used univariate Poisson regression analysis to compare the annualized relapse rate (ARR), log-rank test for the first attack, and the hazard ratios (HR)-calculated using multivariate Andersen-Gill model for recurrent attacks-of the Bio and conventional treatment period groups. The safety of each treatment period group was assessed by comparing infection and mortality rates.

RESULTS

A total of 109 patients (92 % females) met the eligibility criteria of the study. We could extract a total of 1,283 patient years with 289 NMOSD attacks from their medical history data. The mean ARR of no-treatment group was 0.60. Most of the Bio group initially received combined treatments with PSL or IS. The mean ARR of the Bio group was 0.01 [95 % confidence interval (CI): 0.002 to 0.08], which was significantly lower than the PSL-mono group (0.16, 95 % CI: 0.13 to 0.19, p = 0.03) and the IS group (0.17, 95 % CI: 0.13 to 0.22, p = 0.02). In the survival analysis, the Bio group showed a significantly prolonged attack-free period than the other groups, suggesting its potential in reducing 79 % of relapses in the no-treatment group, 33 % in the PSL-mono group, and 31 % in the IS group during the two years. The multivariate analysis using Andersen-Gill model showed that the Bio group had significantly lower HR (log HR -2.75, 95 % CI: -4.71 to -0.8, p = 0.006), relative to the PSL-mono group. Importantly, the patients needed significantly lower PSL (median 5 mg/day) during the Bio group treatment period than in the PSL-mono group treatment period (median 10 mg/day). Further, the concomitant use of IS could be stopped safely in all patients who were on Bio treatment. All treatment period groups showed similar safety profiles.

CONCLUSION

In patients with AQP4-IgG-positive NMOSD, biologics demonstrated more efficacy than conventional PSL and/or IS treatment, without increasing infection and mortality rates.

Interleukin-6 inhibitors for neuromyelitis optica spectrum disorder (NMOSD): A systematic review and meta-analysis

BACKGROUND

Interleukin-6 (IL-6) inhibitors recently emerged as a promising therapy for neuromyelitis optica spectrum disorder (NMOSD).

OBJECTIVE

We performed a systematic review and meta-analysis comparing IL-6 inhibitors to placebo or traditional immunosuppressants in NMOSD.

METHODS

We searched PubMed, Embase, and Cochrane Central for eligible studies. Efficacy endpoints included hazard ratio (HR) for relapse, annualized relapse ratio (ARR) and Expanded Disability Status Scale (EDSS) change over time. Safety outcomes comprised any adverse event, serious adverse events and infections. Statistical analysis was performed using RevMan Web and R studio package meta. Heterogeneity was assessed with I² statistics.

RESULTS

Four studies involving 361 patients (228 treated with IL-6 inhibitors) were included. IL-6 inhibitors significantly reduced HR for relapse (HR 0.35; 95 % CI 0.23, 0.55); p < 0.00001; I² = 0 %) and ARR (mean difference -0.79 relapses/year; 95 % CI -1.54, -0.03; p = 0.04; I² = 96 %) compared to placebo or traditional immunosuppressants. No significant differences were observed in EDSS change over 24 weeks of follow-up (mean difference -0.18; 95 % CI -0.41, 0.05; p = 0.93; I² = 0 %), adverse events (odds ratio (OR) 1.59; 95 % CI 0.45, 5.63; p = 0.48; I² = 48 %), serious adverse events (OR 0.76; 95 % CI 0.40, 1.44; p = 0.50; I² = 0 %) and infection rates (OR 1.10; 95 % CI 0.67, 1.79; p = 0.71; I² = 0 %).

CONCLUSION

IL-6 inhibitors demonstrate superior efficacy in preventing relapses in NMOSD compared to placebo or traditional immunosuppressants, without a notable increase in safety risks.

NMOSD and MOGAD: an evolving disease spectrum

Neuromyelitis optica (NMO) spectrum disorder (NMOSD) is a relapsing inflammatory disease of the CNS, characterized by the presence of serum aquaporin 4 (AQP4) autoantibodies (AQP4-IgGs) and core clinical manifestations such as optic neuritis, myelitis, and brain or brainstem syndromes. Some people exhibit clinical characteristics of NMOSD but test negative for AQP4-IgG, and a subset of these individuals are now recognized to have serum autoantibodies against myelin oligodendrocyte glycoprotein (MOG) - a condition termed MOG antibody-associated disease (MOGAD). Therefore, the concept of NMOSD is changing, with a disease spectrum emerging that includes AQP4-IgG-seropositive NMOSD, MOGAD and double-seronegative NMOSD. MOGAD shares features with NMOSD, including optic neuritis and myelitis, but has distinct pathophysiology, clinical profiles, neuroimaging findings (including acute disseminated encephalomyelitis and/or cortical encephalitis) and biomarkers. AQP4-IgG-seronegative NMOSD seems to be a heterogeneous condition and requires further study. MOGAD can manifest as either a monophasic or a relapsing disease, whereas NMOSD is usually relapsing. This Review summarizes the history and current concepts of NMOSD and MOGAD, comparing epidemiology, clinical features, neuroimaging, pathology and immunology. In addition, we discuss new monoclonal antibody therapies for AQP4-IgG-seropositive NMOSD that target complement, B cells or IL-6 receptors, which might be applied to MOGAD in the near future.

Long-term disability progression in aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder: a retrospective analysis of 101 patients

BACKGROUND

Anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4Ab+NMOSD) is an inflammatory disorder of the central nervous system with relapse-dependent progression. Few studies have reported the effects of prednisolone and biologics on disability progression in AQP4Ab+NMOSD, although it is established that they prevent clinical relapses. This retrospective study investigated long-term disability progression and the effects of therapeutic interventions on disability progression in AQP4Ab+NMOSD.

METHODS

This study included a total of 101 patients with AQP4Ab+NMOSD. Disease progression was investigated in the following two cohorts: (1) duration from disease onset to Expanded Disability Status Scale (EDSS) 3.0 in patients who did or did not receive oral prednisolone or biologics before reaching EDSS 3.0 and (2) duration from disease onset to EDSS 6.0 in patients who did or did not receive oral prednisolone or biologics before reaching EDSS 6.0.

RESULTS

Approximately half of the untreated patients reached EDSS 3.0 and 6.0 at 10 and 46 months after disease onset, respectively. In addition, 88% and 71% of the untreated patients reached EDSS 3.0 and 6.0 within 10 years after disease onset, respectively. Disability progression, clinical relapses and attack severity were suppressed by prednisolone and biologics.

CONCLUSIONS

AQP4Ab+NMOSD is a severely disabling disease. Treatment interventions using prednisolone and biologics are useful in suppressing disability progression in AQP4Ab+NMOSD.

Safety and efficacy of inebilizumab for the treatment of neuromyelitis optica spectrum disorder: end-of-study results from the open-label period of the N-MOmentum trial

BACKGROUND

Inebilizumab, an anti-CD19 B-cell-depleting antibody, demonstrated safety and efficacy in neuromyelitis optica spectrum disorder in the randomised controlled period of the N-MOmentum trial. Here, end-of-study data, including the randomised controlled period and open-label extension period, are reported.

METHODS

In the double-blind, randomised, placebo-controlled, phase 2/3 N-MOmentum trial, adults aged 18 years and older with an neuromyelitis optica spectrum disorder diagnosis, Expanded Disability Status Scale score of 8·0 or less, and history of either at least one acute inflammatory attack requiring rescue therapy in the past year or two attacks requiring rescue therapy in the past 2 years, were recruited from 81 outpatient specialty clinics or hospitals in 24 countries. Eligible participants were randomly assigned (3:1), using a central interactive voice system or interactive web response system, and a permuted block randomisation scheme (block size of 4), to receive intravenous inebilizumab (300 mg) or identical placebo on days 1 and 15 of the randomised period, which lasted up to 197 days. Participants and all study staff were masked to treatment assignment. The primary endpoint of the randomised period of the trial was time to onset of adjudicated neuromyelitis optica spectrum disorder attack on or before day 197. Participants in the randomised controlled period who had an adjudicated attack, completed 197 days in the study, or were in the randomised controlled period when enrolment stopped, could voluntarily enter the open-label period. In the open-label period, participants either initiated inebilizumab if assigned placebo (receiving 300 mg on days 1 and 15 of the open-label period) or continued treatment if assigned inebilizumab (receiving 300 mg on day 1 and placebo on day 15, to maintain B-cell depletion and masking of the randomised controlled period). All participants subsequently received inebilizumab 300 mg every 6 months for a minimum of 2 years. The end-of-study analysis endpoints were time to adjudicated attack and annualised attack rate (assessed in all participants who received inebilizumab at any point during the randomised controlled period or open-label period [any inebilizumab population] and the aquaporin-4 [AQP4]-IgG seropositive subgroup [any inebilizumab-AQP4-IgG seropositive population]) and safety outcomes (in all participants who were exposed to inebilizumab, analysed as-treated). This study is registered with ClinicalTrials.gov, NCT02200770, and is now complete.

FINDINGS

Between Jan 6, 2015, and Sept 24, 2018, 467 individuals were screened, 231 were randomly assigned, and 230 received at least one dose of inebilizumab (n=174) or placebo (n=56). Between May 19, 2015, and Nov 8, 2018, 165 (95%) of 174 participants in the inebilizumab group and 51 (91%) of 56 in the placebo group entered the open-label period (mean age 42·9 years [SD 12·4], 197 [91%] of 216 were female, 19 [9%] were male, 115 [53%] were White, 45 [21%] were Asian, 19 [9%] were American Indian or Alaskan Native, and 19 [9%] were Black or African American). As of data cutoff for this end of study analysis (Dec 18, 2020; median exposure 1178 days [IQR 856-1538], total exposure of 730 person-years) 225 participants formed the any inebilizumab population, and 208 (92%) participants were AQP4-IgG seropositive. Overall, 63 adjudicated neuromyelitis optica spectrum disorder attacks occurred in 47 (21%) of 225 treated participants (60 attacks occurred in 44 [21%] of 208 in the AQP4-IgG seropositive subgroup); 40 (63%) of 63 attacks occurred in 34 (15%) of 225 treated participants during the first year of treatment. Of individuals who had an adjudicated attack while receiving inebilizumab, 36 (77%) of 47 were subsequently attack-free at the end of 4 years. Annualised attack rates decreased year-on-year, with end-of-study adjusted annualised attack rates being similar in the any inebilizumab-AQP4-IgG seropositive subgroup (0·097 [95% CI 0·070-0·14]) and any inebilizumab populations (0·092 [0·067-0·13]). Overall, 208 (92%) of 225 participants who received any inebilizumab had at least one treatment-emergent adverse event, the most frequent of which were urinary tract infection (59 [26%]), nasopharyngitis (47 [21%]), and arthralgia (39 [17%]). Infection rates did not increase over 4 years. Three (1%) of 225 participants in the any inebilizumab population died during the open-label period (one each due to a CNS event of unknown cause and pneumonia, respiratory insufficiency resulting from an neuromyelitis optica spectrum disorder attack and viral pneumonia related to COVID-19), all of which were deemed to be unrelated to treatment.

INTERPRETATION

Data from the end-of-study analysis of the N-MOmentum trial showed continued and sustained clinical benefits of long-term inebilizumab treatment in individuals with neuromyelitis optica spectrum disorder, which supports the role of inebilizumab as a CD19+ B-cell-depleting therapy in neuromyelitis optica spectrum disorder.

FUNDING

MedImmune and Viela Bio/Horizon Therapeutics, now part of Amgen.

Update on the diagnosis and treatment of neuromyelitis optica spectrum disorders (NMOSD) - revised recommendations of the Neuromyelitis Optica Study Group (NEMOS). Part II: Attack therapy and long-term management

This manuscript presents practical recommendations for managing acute attacks and implementing preventive immunotherapies for neuromyelitis optica spectrum disorders (NMOSD), a rare autoimmune disease that causes severe inflammation in the central nervous system (CNS), primarily affecting the optic nerves, spinal cord, and brainstem. The pillars of NMOSD therapy are attack treatment and attack prevention to minimize the accrual of neurological disability. Aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) are a diagnostic marker of the disease and play a significant role in its pathogenicity. Recent advances in understanding NMOSD have led to the development of new therapies and the completion of randomized controlled trials. Four preventive immunotherapies have now been approved for AQP4-IgG-positive NMOSD in many regions of the world: eculizumab, ravulizumab - most recently-, inebilizumab, and satralizumab. These new drugs may potentially substitute rituximab and classical immunosuppressive therapies, which were as yet the mainstay of treatment for both, AQP4-IgG-positive and -negative NMOSD. Here, the Neuromyelitis Optica Study Group (NEMOS) provides an overview of the current state of knowledge on NMOSD treatments and offers statements and practical recommendations on the therapy management and use of all available immunotherapies for this disease. Unmet needs and AQP4-IgG-negative NMOSD are also discussed. The recommendations were developed using a Delphi-based consensus method among the core author group and at expert discussions at NEMOS meetings.

Neuromyelitis Optica: Pathogenesis Overlap with Other Autoimmune Diseases

PURPOSE OF REVIEW

Neuromyelitis optica (NMO) is an auto-immune disease essentially depicted by optic neuritis and transverse myelitis. Per se, NMO was initially believed to be a sub-type of multiple sclerosis with typical demyelinating cerebral lesions and optic nerve inflammation. More recently, corroborating lignes of evidence have strengthened the concept of the spectrum of diseases associated with NMO and more specifically with the role of anti-aquaporin-4 antibodies in the pathogenesis of disease.

RECENT FINDINGS

In this article, we review the recent pathogenic findings in NMO and more interestingly the newly discovered role of anti-aquaporin-4 antibodies as key players in triggering cerebral lesions. The concept of spectrum of diseases associated with NMO is also discussed. These recent findings have paved in the further understanding of the pathogenesis underlying NMO and new treatments are currently being developed targeting anti-aquaporin-4 antibodies.

Higher longitudinal brain white matter atrophy rate in aquaporin-4 IgG-positive NMOSD compared with healthy controls

We aimed to compare longitudinal brain atrophy in patients with neuromyelitis optica spectrum disorder (NMOSD) with healthy controls (HCs). The atrophy rate in patients with anti-aquaporin-4 antibody-positive NMOSD (AQP4 + NMOSD) was compared with age-sex-matched HCs recruited from the Japanese Alzheimer's Disease Neuroimaging Initiative study and another study performed at Chiba University. Twenty-nine patients with AQP4 + NMOSD and 29 HCs were enrolled in the study. The time between magnetic resonance imaging (MRI) scans was longer in the AQP4 + NMOSD group compared with the HCs (median; 3.2 vs. 2.9 years, P = 0.009). The annualized normalized white matter volume (NWV) atrophy rate was higher in the AQP4 + NMOSD group compared with the HCs (median; 0.37 vs. - 0.14, P = 0.018). The maximum spinal cord lesion length negatively correlated with NWV at baseline MRI in patients with AQP4 + NMOSD (Spearman's rho =  - 0.41, P = 0.027). The annualized NWV atrophy rate negatively correlated with the time between initiation of persistent prednisolone usage and baseline MRI in patients with AQP4 + NMOSD (Spearman's rho =  - 0.43, P = 0.019). Patients with AQP4 + NMOSD had a greater annualized NWV atrophy rate than HCs. Suppressing disease activity may prevent brain atrophy in patients with AQP4 + NMOSD.

Long-term safety and effectiveness of eculizumab in patients with aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder: a 2-year interim analysis of post-marketing surveillance in Japan

Background

The terminal complement C5 inhibitor eculizumab is approved in Japan for relapse prevention in aquaporin-4 antibody-positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD) and is undergoing mandatory post-marketing surveillance (PMS) of clinical use.

Objectives

The objective of the study is to assess the real-world, long-term safety and effectiveness of eculizumab in Japanese patients with AQP4+ NMOSD.

Design

Regulatory-mandated PMS analysis implemented as an all-case surveillance of all patients with AQP4+ NMOSD who have been treated with eculizumab in Japan since its approval in November 2019.

Methods

This PMS interim analysis assessed the safety and effectiveness of eculizumab in Japanese patients with AQP4+ NMOSD from November 2019 to April 2022.

Results

Of 147 patients treated with eculizumab who consented to publication, 71 had at least one case report form collected and locked at the interim analysis data cut-off, constituting the safety analysis set; three patients from PREVENT (NCT01892345) were excluded from the effectiveness analysis set. Twelve and 10 patients in the safety and effectiveness analysis sets discontinued, respectively. In the safety analysis set, 67/71 patients (94.4%) were female, mean illness duration was 6.8 [standard deviation (SD): 6.2] years, mean age at eculizumab initiation was 50.7 (SD: 13.3) years, and mean eculizumab treatment duration was 44.6 (SD: 23.7) weeks. At diagnosis of NMOSD, 34/71 patients (47.9%) and 35/71 patients (49.3%) in the safety analysis set had symptoms of optic neuritis and transverse myelitis, respectively. In the safety analysis set, 19/71 patients (26.8%) reported adverse events, 10/71 (14.1%) reported adverse drug reactions (ADRs), and 7/71 (9.9%) reported serious ADRs; no meningococcal infections were observed. In the effectiveness analysis set, 64/68 patients (94.1%) were female, mean disease duration was 6.9 (SD: 6.3) years, mean age at eculizumab initiation was 50.6 (SD: 13.2) years, and 27/68 (39.7%) were tested for C5 genetic polymorphism (all negative). In the 2 years before eculizumab, 51/68 patients (75.0%) experienced relapse. Relapse rate was 0.02/patient-year after eculizumab initiation versus 0.74/patient-year in the 2 years before eculizumab. Overall, 37/68 patients (54.4%) were prescribed immunosuppressants in the 6 months before and 19/40 (47.5%) in the 6-12 months after starting eculizumab treatment. The proportion of patients taking >10 mg/day of prednisolone decreased from 45.6% at 24-20 weeks before to 23.1% and 0% at 48-52 and 100-104 weeks after eculizumab, respectively.

Conclusion

This article reports interim PMS data for Japanese patients and provides updated real-world evidence for the safety of eculizumab and its effectiveness at preventing relapses in patients with AQP4+ NMOSD. Safety and effectiveness results are consistent with those from PREVENT.

A real-world study of interleukin-6 receptor blockade in patients with neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune disease that can cause permanent neurological disabilities. However, the interleukin-6 (IL-6) signaling pathway is a promising therapeutic target for relapse prevention. Therefore, this study evaluated the long-term effectiveness of tocilizumab, a humanized anti-IL-6 receptor antibody, for NMOSD. We enrolled 65 patients with NMOSD who received regular intravenous administration of tocilizumab (8 mg/kg) between October 2017 and January 2022. Then, we retrospectively collected data on the clinical characteristics and baseline glial fibrillary acidic protein (GFAP) and neurofilament light chain levels. The primary outcome was the annualized relapse rate (ARR). Risk factors were assessed using a multivariable logistic regression model. During the median follow-up of 34.1 (interquartile range: 25.5-39.3) months, 23% (15/65) of patients relapsed during tocilizumab treatment, but the median ARR decreased from 1.9 (range 0.12-6.29) to 0.1 (range 0-1.43, p < 0.0001). A prolonged infusion interval (> 4 weeks, odds ratio [OR]: 10.7, 95% confidence interval [CI]: 1.6-71.4, p = 0.014) and a baseline plasma GFAP level of > 220 pg/mL (OR: 20.6, 95% CI 3.3-129.4, p  = 0.001) were risk factors for future relapses. During treatment, the median Expanded Disability Status Scale score significantly decreased in aquaporin-4 antibody-positive and -negative patients, but the pain did not considerably improve. There were no severe safety concerns. Tocilizumab treatment significantly reduced the relapse rate in patients with NMOSD. However, prolonged infusion intervals and high baseline plasma GFAP levels may increase the relapse risk during tocilizumab therapy.

Neuromyelitis Optica Spectrum Disorders

PURPOSE OF REVIEW

This article reviews the cardinal clinical features, distinct immunopathology, current diagnostic criteria, relapse-related risk factors, emerging biomarkers, and evolving treatment strategies pertaining to neuromyelitis optica spectrum disorders (NMOSD).

RECENT FINDINGS

The discovery of the pathogenic aquaporin-4 (AQP4)-IgG autoantibody and characterization of NMOSD as an autoimmune astrocytopathy have spearheaded the identification of key immunologic therapeutic targets in this disease, including but not limited to the complement system, the interleukin 6 (IL-6) receptor, and B cells. Accordingly, four recent randomized controlled trials have demonstrated the efficacy of three new NMOSD therapies, namely eculizumab, satralizumab, and inebilizumab.

SUMMARY

Currently, NMOSD poses both diagnostic and treatment challenges. It is debated whether individuals who are seropositive for myelin oligodendrocyte glycoprotein (MOG)-IgG belong within the neuromyelitis optica spectrum. This discussion is fueled by disparities in treatment responses between patients who are AQP4-IgG seropositive and seronegative, suggesting different immunopathologic mechanisms may govern these conditions. As our understanding regarding the immune pathophysiology of NMOSD expands, emerging biomarkers, including serum neurofilament light chain and glial fibrillary acidic protein (GFAP), may facilitate earlier relapse detection and inform long-term treatment decisions. Future research focal points should include strategies to optimize relapse management, restorative treatments that augment neurologic recovery, and practical solutions that promote equitable access to approved therapies for all patients with NMOSD.

Contemporary management challenges in seropositive NMOSD

Neuromyelitis optica spectrum disorders (NMOSD) is an inflammatory disorder of the central nervous system that presents unique management challenges. Neurologic disability in NMOSD is directly linked to acute attacks, therefore, relapse prevention is an overarching goal of care. To this end, identifying effective biomarkers that predict relapse onset and severity is of critical importance. As treatment becomes more precision-based and patient-centred, clinicians will need to be familiar with managing circumstances of particular vulnerability for patients with NMOSD, including infection, pregnancy, and the post-partum phase. The discovery of the pathogenic aquaporin-4 Immunoglobulin G (AQP4 IgG) autoantibody almost 20 years ago ultimately distinguished NMOSD as an autoimmune astrocytopathy and helped spearhead recent therapeutic advancements. Targeted therapies, including eculizumab, satralizumab, and inebilizumab, approved for use in aquaporin-4 immunoglobulin G (AQP4 IgG) seropositive patients with NMOSD will likely improve outcomes, but there are formidable costs involved. Importantly, seronegative patients continue to have limited therapeutic options. Moving forward, areas of research exploration should include relapse prevention, restorative therapies, and initiatives that promote equitable access to approved therapies for all people living with NMOSD.

Comparison on the effect of seven drugs to prevent relapses of neuromyelitis optica spectrum disorders: A modeling analysis of literature aggregate data

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is an immune-mediated demyelinating disease of the central nervous system. This study aimed to perform a comprehensive comparison of the effect of seven drugs to prevent relapses of NMOSD.

METHOD

A literature search was conducted using public databases. Clinical studies on the seven drugs (eculizumab, inebilizumab, satralizumab, rituximab, tocilizumab, azathioprine, and mycophenolate mofetil) to prevent relapses of NMOSD were identified. A time-course model was established using the time to first relapse as the primary endpoint, in order to evaluate the long-term effect of each drug in preventing relapse.

RESULTS

Twenty-four trials, including 2207 patients, were included in the model analysis. The results showed that monoclonal antibody therapy could significantly prolong the time to first relapse. Among all seven drugs, eculizumab can most significantly prevent patient from relapse. The estimated proportion of relapse-free patients treated with eculizumab was 98.9% at 24 months.

CONCLUSION

Based on the construction of a time-course pharmacodynamic model, this study made a comprehensive quantitative comparison of seven drugs for the treatment of NMOSD for the first time. These results can not only serve as a quantitative supplement for the rational use of drugs in clinical practice but also provide a pharmacodynamic reference for clinical trial design and decision making in the future.

What's new in neuromyelitis optica spectrum disorder treatment?

Optic neuritis, an optic nerve inflammatory disease presenting with acute unilateral or bilateral visual loss, is one of the core symptoms of neuromyelitis optica spectrum disorder (NMOSD). The diagnosis of NMOSD-related optic neuritis is challenging, and it is mainly based on clinical presentation, optical coherence tomography, magnetic resonance imaging scans, and the status of serum aquaporin-4 antibodies. In the pathogenesis, aquaporin-4 antibodies target astrocytes in the optic nerves, spinal cord and some specific regions of the brain eliciting a devastating autoimmune response. Current pharmacological interventions are directed against various steps within the immunological response, notably the terminal complement system, B-cells, and the pro-inflammatory cytokine Interleukin 6 (IL6). Conventional maintenance therapies were off-label uses of the unspecific immunosuppressants azathioprine and mycophenolate mofetil as well as the CD20 specific antibody rituximab and the IL6 receptor specific antibody tocilizumab. Recently, four phase III clinical trials demonstrated the safety and efficacy of the three novel biologics eculizumab, inebilizumab, and satralizumab. These monoclonal antibodies are directed against the complement system, CD19 B-cells and the IL6 receptor, respectively. All three have been approved for NMOSD in the US and several other countries worldwide and thus provide convincing treatment options.

Relapse activity in the chronic phase of anti-myelin-oligodendrocyte glycoprotein antibody-associated disease

Objective

The patterns of relapse and relapse-prevention strategies for anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are not completely investigated. We compared the patterns of relapse in later stages of MOGAD with those of anti-aquaporin-4 antibody (AQP4-Ab)-positive neuromyelitis optica spectrum disorder (NMOSD).

Methods

In this observational, comparative cohort study, 66 patients with MOGAD and 90 with AQP4-Ab-positive NMOSD were enrolled. We compared the patterns of relapse and annualized relapse rates (ARRs) in the first 10 years from disease onset, stratified by relapse-prevention treatments.

Results

Approximately 50% of the patients with MOGAD experienced relapses in the first 10 years. Among those not undergoing relapse-prevention treatments, ARRs in the first 5 years were slightly lower in MOGAD patients than in AQP4-Ab-positive NMOSD patients (MOGAD vs. AQP4-Ab NMOSD: 0.19 vs. 0.30; p = 0.0753). After 5 years, the ARR decreased in MOGAD patients (MOGAD vs. AQP4-Ab NMOSD: 0.05 vs. 0.34; p = 0.0001), with a 72% reduction from the first 5 years (p = 0.0090). Eight (61.5%) of the 13 MOGAD patients with more than 10-year follow-up from disease onset showed relapse 10 years after onset. Clustering in the timing and phenotype of attacks was observed in both disease patients. The effectiveness of long-term low-dose oral PSL for relapse prevention in patients with MOGAD has not been determined.

Conclusions

The relapse risk in patients with MOGAD is generally lower than that in patients with AQP4-Ab-positive NMOSD, especially 5 years after onset. Meanwhile, relapses later than 10 years from onset are not rare in both diseases.

Treatment response, risk of relapse and clinical characteristics of Taiwanese patients with neuromyelitis optica spectrum disorder

BACKGROUND/PURPOSE

The long-term disease course and efficacy of maintenance therapies have rarely been investigated in Asian patients with neuromyelitis optica spectrum disorder (NMOSD).

METHODS

Medical records of patients fulfilling the 2015 International Consensus Diagnostic Criteria for NMOSD at three medical centers in Taiwan were systematically analyzed. Linear regression analysis was performed to investigate factors related to annualized relapse rate (ARR); survival analysis was used to estimate the relapse-free intervals among therapies.

RESULTS

A total of 557 relapses affecting 648 regions (202 optic neuritis, 352 acute myelitis, and 94 brain syndromes) in 204 patients were analyzed during a follow-up period of 69.5 months (range, 1-420). Up to 36.1% of myelitis-onset patients and 24.0% of optic neuritis-onset patients exhibited a limited form disease, defined as having one or more relapses confined to the same region. The median ARR was significantly lower in patients with limited form disease than those with relapses involving multiple regions (0.30 vs. 0.47, respectively). An older age at disease onset was associated with a lower ARR (p = 0.023). Kaplan-Meier analysis showed that the estimated time (months) to next relapse was longest in rituximab-treatment group (58.0 ± 13.2), followed by immunosuppressant (48.5 ± 4.8) or prednisone (29.6 ± 4.6) groups, and shortest in those without maintenance therapy (27.6 ± 4.2) (p = 8.1 × 10^-7).

CONCLUSION

Limited form disease and older age at disease onset are associated with a lower relapse rate in NMOSD. Compared to no maintenance therapy, rituximab and immunosuppressant significantly reduce the relapse risks.