Benefits of eculizumab in AQP4+ neuromyelitis optica spectrum disorder: Subgroup analyses of the randomized controlled phase 3 PREVENT trial

Eculizumab Use in Neuromyelitis Optica Spectrum Disorders: Routine Clinical Care Data From a European Cohort

BACKGROUND AND OBJECTIVES

Attack prevention is crucial in managing neuromyelitis optica spectrum disorders (NMOSDs). Eculizumab (ECU), an inhibitor of the terminal complement cascade, was highly effective in preventing attacks in a phase III trial of aquaporin-4 (AQP4)-IgG seropositive(+) NMOSDs. In this article, we evaluated effectiveness and safety of ECU in routine clinical care.

METHODS

We retrospectively evaluated patients with AQP4-IgG+ NMOSD treated with ECU between December 2014 and April 2022 at 20 German and 1 Austrian university center(s) of the Neuromyelitis Optica Study Group (NEMOS) by chart review. Primary outcomes were effectiveness (assessed using annualized attack rate [AAR], MRI activity, and disability changes [Expanded Disability Status Scale {EDSS}]) and safety (including adverse events, mortality, and attacks after meningococcal vaccinations), analyzed by descriptive statistics.

RESULTS

Fifty-two patients (87% female, age 55.0 ± 16.3 years) received ECU for 16.2 (interquartile range [IQR] 9.6 - 21.7) months. Forty-five patients (87%) received meningococcal vaccination before starting ECU, 9 with concomitant oral prednisone and 36 without. Seven of the latter (19%) experienced attacks shortly after vaccination (median: 9 days, IQR 6-10 days). No postvaccinal attack occurred in the 9 patients vaccinated while on oral prednisone before starting ECU and in 25 (re-)vaccinated while on ECU. During ECU therapy, 88% of patients were attack-free. The median AAR decreased from 1.0 (range 0-4) in the 2 years preceding ECU to 0 (range 0-0.8; p < 0.001). The EDSS score from start to the last follow-up was stable (median 6.0), and the proportion of patients with new T2-enhancing or gadolinium-enhancing MRI lesions in the brain and spinal cord decreased. Seven patients (13%) experienced serious infections. Five patients (10%; median age 53.7 years) died on ECU treatment (1 from myocardial infarction, 1 from ileus with secondary sepsis, and 3 from systemic infection, including 1 meningococcal sepsis), 4 were older than 60 years and severely disabled at ECU treatment start (EDSS score ≥ 7). The overall discontinuation rate was 19%.

DISCUSSION

Eculizumab proved to be effective in preventing NMOSD attacks. An increased risk of attacks after meningococcal vaccination before ECU start and potentially fatal systemic infections during ECU-particularly in patients with comorbidities-must be considered. Further research is necessary to explore optimal timing for meningococcal vaccinations.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that eculizumab reduces annualized attack rates and new MRI lesions in AQP4-IgG+ patients with NMOSD.

Role of C5 inhibitors in neuromyelitis optica spectrum disorders with seropositive anti-aquaporin-4 antibody: A systematic review and meta-analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder characterized by relapses of inflammation and demyelination primarily affecting the optic nerve and the spinal cord. C5 complement inhibition is an effective therapeutic approach in the treatment of NMOSD. In this systematic review and meta-analysis, we aimed to determine the role of C5 inhibitors in the treatment of patients with seropositive anti-aquaporin-4 antibody (AQP4+IgG) NMOSD.

METHODS

This systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Relevant articles were systematically searched through Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases until October 6th, 2023. We included randomized clinical trials (RCTs) that investigated the treatment with C5 inhibitors compared to placebo in patients with seropositive NMOSD. The primary endpoint was the rates of first adjudicated relapse. Secondary endpoints included different disability and quality of life measures. The random-effects model was used for all statistical analyses.

RESULTS

Two RCTs with a total of 201 patients were included. C5 inhibitors demonstrated significant reduction of first adjudicated relapse (risk ratio (RR) = 0.05, 95 % CI 0.01-0.15) and Hauser Ambulation Index (HAI) (mean difference (MD): -0.79, 95 % CI -1.27 to -0.31). There was no significant difference between the two groups in Expanded Disability Status Scale (EDSS) (MD -0.23, 95 % CI -0.54-0.08). C5 inhibitors significantly improved the mean change in EQ-5D index (MD 0.08, 95 % CI 0.01-0.14; P = 0.02); however, no significant difference was shown in the mean change in EQ-5D VAS (MD 3.79, 95 % CI -1.61 to 9.19; P = 0.17). Safety measures were comparable between C5 inhibitors and placebo.

CONCLUSION

NMOSD Patients with AQP4+IgG receiving C5 inhibitors have lower rate of relapses and improved levels of disability and quality of life. Real-world studies are warranted to establish the long-term safety of C5 inhibitors.

Predicting time to serologic diagnosis of AQP4+ NMOSD based on clinical factors and social determinants of health

BACKGROUND

Early serologic diagnosis and initiation of targeted therapy are associated with better outcomes in aquaporin-4 IgG positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD).

OBJECTIVE

To determine predictors of time to serologic diagnosis of AQP4+ NMOSD.

METHODS

In CANOPTICS, a multi-centre, Canadian cohort study of NMOSD, we retrospectively evaluated time from the first clinical attack to first positive AQP4-IgG serology. We used a multivariable negative binomial regression model to evaluate possible predictors of time to diagnosis.

RESULTS

We identified 129 participants with AQP4+ NMOSD from 7 centres. Diagnostic delay of >1 month was observed in 82 (63.6 %). Asian compared to European (White) ethnicity (IRR:0.40, 95 % CI:0.21-0.78), female sex (IRR:0.56, 95 % CI:0.32-0.99), later calendar year (IRR:0.84, 95 % CI:0.81-0.86), and hospitalization for the first attack (IRR:0.35, 95 % CI:0.20-0.62) were associated with shorter times to serologic diagnosis. We did not observe any overall effect of Afro-Caribbean ethnicity, but in exploratory analyses, Afro-Caribbean individuals with low income had longer times to diagnosis.

CONCLUSION

More than 60 % of patients with NMOSD experienced delays to AQP4-IgG serologic diagnosis in this cohort. Given evidence of more adverse long-term outcomes in Afro-Caribbean individuals with NMOSD, intersectional effects of ethnicity and social determinants of health merit further study.

Treatment of neuromyelitis optica spectrum disorder: revisiting the complement system and other aspects of pathogenesis

Neuromyelitis optica spectrum disorder (NMOSD) represents a rare neuroimmunological disease causing recurrent attacks and accumulation of permanent disability in affected patients. The discovery of the pathogenic IgG‑1 antibody targeting a water channel expressed in astrocytes, aquaporin 4, constitutes a milestone achievement. Subsequently, multiple pathophysiological aspects of this distinct disease entity have been investigated. Demyelinating lesions and axonal damage ensue from autoantibodies targeting an astroglial epitope. This conundrum has been addressed in the current disease model, where activation of the complement system as well as B cells and interleukin 6 (IL-6) emerged as key contributors. It is the aim of this review to address these factors in light of novel treatment compounds which reflect these pathophysiological concepts in aiming for attack prevention, thus reducing disease burden in patients with NMOSD.

Updates in NMOSD and MOGAD Diagnosis and Treatment: A Tale of Two Central Nervous System Autoimmune Inflammatory Disorders

Aquaporin-4-IgG positive neuromyelitis optica spectrum disorder (AQP4+NMOSD) and myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are antibody-associated diseases targeting astrocytes and oligodendrocytes, respectively. Their recognition as distinct entities has led to each having its own diagnostic criteria that require a combination of clinical, serologic, and MRI features. The therapeutic approach to acute attacks in AQP4+NMOSD and MOGAD is similar. There is now class 1 evidence to support attack-prevention medications for AQP4+NMOSD. MOGAD lacks proven treatments although clinical trials are now underway. In this review, we will outline similarities and differences between AQP4+NMOSD and MOGAD in terms of diagnosis and treatment.

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.

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

A Clinical Approach to Existing and Emerging Therapeutics in Neuromyelitis Optica Spectrum Disorder

PURPOSE OF REVIEW

Neuromyelitis optica spectrum disorder (NMOSD) is a rare but highly disabling disease of the central nervous system. Unlike multiple sclerosis, disability in NMOSD occurs secondary to relapses that, not uncommonly, lead to blindness, paralysis, and death. Recently, newer, targeted immunotherapies have been trialed and are now in the treatment arsenal. We have endeavoured to evaluate the current state of NMOSD therapeutics.

RECENT FINDINGS

This review provides a pragmatic evaluation of recent clinical trials and post-marketing data for rituximab, inebilizumab, satralizumab, eculizumab, and ravalizumab, contrasted to older agents. We also review contemporary issues such as treatment in the context of SARS-CoV2 infection and pregnancy. There has been a dramatic shift in NMOSD morbidity and mortality with earlier and improved disease recognition, diagnostic accuracy, and the advent of more effective, targeted therapies. Choosing a maintenance therapy remains nuanced depending on patient factors and accessibility. With over 100 putative agents in trials, disease-free survival is now a realistic goal for NMOSD patients.

Ravulizumab in Aquaporin-4-Positive Neuromyelitis Optica Spectrum Disorder

OBJECTIVE

CHAMPION-NMOSD (NCT04201262) is a phase 3, open-label, externally controlled interventional study evaluating the efficacy and safety of the terminal complement inhibitor ravulizumab in adult patients with anti-aquaporin-4 antibody-positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD). Ravulizumab binds the same complement component 5 epitope as the approved therapeutic eculizumab but has a longer half-life, enabling an extended dosing interval (8 vs 2 weeks).

METHODS

The availability of eculizumab precluded the use of a concurrent placebo control in CHAMPION-NMOSD; consequently, the placebo group of the eculizumab phase 3 trial PREVENT (n = 47) was used as an external comparator. Patients received weight-based intravenous ravulizumab on day 1 and maintenance doses on day 15, then once every 8 weeks. The primary endpoint was time to first adjudicated on-trial relapse.

RESULTS

The primary endpoint was met; no patients taking ravulizumab (n = 58) had an adjudicated relapse (during 84.0 patient-years of treatment) versus 20 patients with adjudicated relapses in the placebo group of PREVENT (during 46.9 patient-years; relapse risk reduction = 98.6%, 95% confidence interval = 89.7%-100.0%, p < 0.0001). Median (range) study period follow-up time was 73.5 (11.0-117.7) weeks for ravulizumab. Most treatment-emergent adverse events were mild/moderate; no deaths were reported. Two patients taking ravulizumab experienced meningococcal infections. Both recovered with no sequelae; one continued ravulizumab treatment.

INTERPRETATION

Ravulizumab significantly reduced relapse risk in patients with AQP4+ NMOSD, with a safety profile consistent with those of eculizumab and ravulizumab across all approved indications. ANN NEUROL 2023;93:1053-1068.

Systematic Review of Treatment Options and Therapeutic Responses for Lesions of the Sella and Orbit: Evidence-Based Recommendations

OBJECTIVE

Inflammatory pathologies of the sella and orbit are rare but require prompt diagnosis to initiate effective treatment. Because uniform recommendations for treatment are currently lacking, we performed an evidence-based review to identify recommendations.

METHODS

We performed a literature search of the PubMed, Embase, and Web of Science databases to identify papers evaluating treatment of inflammatory pathologies of the sella and orbit. We used PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to define recommendations, specifically examining aggregated sample sizes, disease-specific patient follow-up, and clinical trials focused on inflammatory diseases of the sella and orbit.

RESULTS

A total of 169 studies were included and organized by disease pathology. Treatments for various pathologies were recorded. Treatment options included surgery, radiation, steroids, targeted treatments, immunomodulators, intravenous immune globulin, and plasmapheresis. Steroids were the most often employed treatment, second-line management options and timing varied. Pathological diagnosis was highly associated with treatment used. Most evidence were level 3 without available control groups, except for 13 trials in neuromyelitis optica with level 1 or 2 evidence.

CONCLUSIONS

This is the first evidence-based review to provide recommendations on specific treatments for pathologies of the orbit and sella. The reported data may be useful to help guide randomized clinical trials and provide resource for clinical management decisions based on the available evidence.

The case for complement component 5 as a target in neurodegenerative disease

INTRODUCTION

Complement-based drug discovery is undergoing a renaissance, empowered by new advances in structural biology, complement biology and drug development. Certain components of the complement pathway, particularly C1q and C3, have been extensively studied in the context of neurodegenerative disease, and established as key therapeutic targets. C5 also has huge therapeutic potential in this arena, with its druggability clearly demonstrated by the success of C5-inhibitor eculizumab.

AREAS COVERED

We will discuss the evidence supporting C5 as a target in neurodegenerative disease, along with the current progress in developing different classes of C5 inhibitors and the gaps in knowledge that will help progress in the field.

EXPERT OPINION

Validation of C5 as a therapeutic target for neurodegenerative disease would represent a major step forward for complement therapeutics research and has the potential to furnish disease-modifying drugs for millions of patients suffering worldwide. Key hurdles that need to be overcome for this to be achieved are understanding how C5a and C5b should be targeted to bring therapeutic benefit and demonstrating the ability to target C5 without creating vulnerability to infection in patients. This requires greater biological elucidation of its precise role in disease pathogenesis, supported by better chemical/biological tools.

Sex and gender differences in autoimmune demyelinating CNS disorders: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and myelin-oligodendrocyte-glycoprotein antibody associated disorder (MOGAD)

Multiple sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD) and Myelin-Oligodendrocyte-Glycoprotein antibody associated disorder (MOGAD) are demyelinating disorders of the central nervous system (CNS) of autoimmune origin. Here, we summarize general considerations on sex-specific differences in the immunopathogenesis and hormonal influences as well as key clinical and epidemiological elements. Gender-specific issues are widely neglected starting with the lacking separation of sex as a biological variable and gender comprising the sociocultural components. As for other autoimmune diseases, female preponderance is common in MS and NMOSD. However, sex distribution in MOGAD seems equal. As in MS, immunotherapy in NMOSD and MOGAD is crucial to prevent further disease activity. Therefore, we assessed data on sex differences of the currently licensed disease-modifying treatments for efficacy and safety. This topic seems widely neglected with only fragmented information resulting from post-hoc analyses of clinical trials or real-world post-marketing studies afflicted with lacking power and/or inherent sources of bias. In summary, biological hypotheses of sex differences including genetic factors, the constitution of the immune system and hormonal influences are based upon human and preclinical data, especially for the paradigmatic disease of MS whereas specific data for NMOSD and MOGAD are widely lacking. Epidemiological and clinical differences between men and women are well described for MS and to some extent for NMOSD, yet, with remaining contradictory findings. MOGAD needs further detailed investigation. Sex-specific analyses of safety and efficacy of long-term immunotherapies need to be addressed in future studies designed and powered to answer the pressing questions and to optimize and individualize treatment.

The role of complement and complement therapeutics in neuromyelitis optica spectrum disorders

INTRODUCTION

Neuromyelitis optica spectrum disorders (NMOSD) are characterized in the majority of cases by the presence of IgG1 autoantibodies against aquaporin 4 (AQP4) and myelin-oligodendrocyte glycoprotein (MOG), both capable of activating complement.

AREAS COVERED

We review evidence of complement involvement in NMOSD pathophysiology from pathological, in vitro, in vivo, human studies, and clinical trials.

EXPERT OPINION

In AQP4 NMOSD, complement deposition is a prominent pathological feature, while in vitro and in vivo studies have demonstrated complement-dependent pathogenicity of AQP4 antibodies. Consistent with these studies, the anti-C5 monoclonal antibody eculizumab was remarkably effective and safe in a phase 2/3 trial of AQP4-NMOSD patents leading to FDA-approved indication. Several other anti-complement agents, either approved or in trials for other neuro-autoimmunities, like myasthenia, CIDP, and GBS, are also relevant to NMOSD generating an exciting group of evolving immunotherapies. Limited but compelling in vivo and in vitro data suggest that anti-complement therapeutics may be also applicable to a subset of MOG NMOSD patients with severe disease. Overall, anticomplement agents, along with the already approved anti-IL6 and anti-CD19 monoclonal antibodies sartralizumab and inebilizumab, are rapidly changing the therapeutic algorithm in NMOSD, a previously difficult-to-treat autoimmune neurological disorder.

Progress in treatment of neuromyelitis optica spectrum disorders (NMOSD): Novel insights into therapeutic possibilities in NMOSD

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune inflammatory demyelinating disorder of the central nervous system (CNS), which is a severely disabling disorder leading to devastating sequelae or even death. Repeated acute attacks and the presence of aquaporin-4 immunoglobulin G (AQP4-IgG) antibody are the typical characteristics of NMOSD. Recently, the phase III trials of the newly developed biologicals therapies have shown their effectiveness and good tolerance to a certain extent when compared with the traditional therapy with the first- and second-line drugs. However, there is still a lack of large sample, double-blind, randomized, clinical studies to confirm their efficacy, safety, and tolerability. Especially, these drugs have no clear effect on NMOSD patients without AQP4-IgG and refractory patients. Therefore, it is of strong demand to further conduct large sample, double-blind, randomized, clinical trials, and novel therapeutic possibilities in NMOSD are discussed briefly here.

In utero exposure to maternal anti-aquaporin-4 antibodies alters brain vasculature and neural dynamics in male mouse offspring

The fetal brain is constantly exposed to maternal IgG before the formation of an effective blood-brain barrier (BBB). Here, we studied the consequences of fetal brain exposure to an antibody to the astrocytic protein aquaporin-4 (AQP4-IgG) in mice. AQP4-IgG was cloned from a patient with neuromyelitis optica spectrum disorder (NMOSD), an autoimmune disease that can affect women of childbearing age. We found that embryonic radial glia cells in neocortex express AQP4. These cells are critical for blood vessel and BBB formation through modulation of the WNT signaling pathway. Male fetuses exposed to AQP4-IgG had abnormal cortical vasculature and lower expression of WNT signaling molecules Wnt5a and Wnt7a. Positron emission tomography of adult male mice exposed in utero to AQP4-IgG revealed increased blood flow and BBB leakiness in the entorhinal cortex. Adult male mice exposed in utero to AQP4-IgG had abnormal cortical vessels, fewer dendritic spines in pyramidal and stellate neurons, and more S100β+ astrocytes in the entorhinal cortex. Behaviorally, they showed impairments in the object-place memory task. Neural recordings indicated that their grid cell system, within the medial entorhinal cortex, did not map the local environment appropriately. Collectively, these data implicate in utero binding of AQP4-IgG to radial glia cells as a mechanism for alterations of the developing male brain and adds NMOSD to the conditions in which maternal IgG may cause persistent brain dysfunction in offspring.

Adverse Events in NMOSD Therapy

Neuromyelitis optica spectrum disorders (NMOSD) are rare neurologic autoimmune diseases that have a poor prognosis if left untreated. For many years, generic oral immunosuppressants and repurposed monoclonal antibodies that target the interleukin-6 pathway or B cells were the mainstays of drug treatment. Recently, these drug treatments have been complemented by new biologics developed and approved specifically for NMOSD. In principle, all of these drugs are effective, but treatment recommendations that take this into account are still pending. Instead, the choice of a drug may depend on other criteria such as drug safety or tolerability. In this review, we summarise current knowledge on the adverse effects of azathioprine, mycophenolate mofetil, rituximab, tocilizumab, eculizumab, satralizumab, and inebilizumab in NMOSD. Infections, cytopenias, and infusion-related reactions are most common, but the data are as heterogeneous as the manifestations are diverse. Nevertheless, knowledge of safety issues may facilitate treatment choices for individual patients.

Anti-complement Agents for Autoimmune Neurological Disease

In recent years, there has been increasing recognition of the diversity of autoimmune neurological diseases affecting all levels of the nervous system. A growing understanding of disease pathogenesis has enabled us to better target specific elements of the immune system responsible for the cell dysfunction and cell destruction seen in these diseases. This is no better demonstrated than in the development of complement directed therapies for the treatment of complement mediated autoimmune neurological conditions. Herein, we describe the basic elements of the complement cascade, provide an overview of select autoimmune neurological diseases whose pathogenesis is mediated by complement, the effector system of autoantigen bound autoantibodies, and discuss the complement directed therapies trialed in the treatment of these diseases. Several complement-directed therapies have demonstrated benefit in the treatment of autoimmune neurological diseases; we also review the trials resulting in the approval of these therapies for the treatment of AChR Ab-positive myasthenia gravis (MG) and neuromyelitis spectrum disorder. Finally, on the heels of the recent successes described, we discuss possibilities for the future, including additional targeted therapies with greater ease of administration, improved risk profiles, and other possible uses for therapeutics targeting elements of the complement cascade.

[Clinical and epidemiological aspects of neuromyelitis optic spectrum diseases in the russian population]

OBJECTIVE

To present clinical and epidemiological aspects of neuromyelitis optica spectrum disorders (NMOSD) in the Russian Federation.

MATERIAL AND METHODS

We studied 142 patients who met diagnostic criteria of 2015 for NMOSD. Sex, age at disease onset, presence or absence of aquaporin-4 immunoglobulin G antibodies (AQP4-IgG), mail clinical symptoms, oligoclonal IgG, therapy for the treatment of exacerbations and prevention of exacerbations, compliance with 2006 diagnostic criteria were assessed.

RESULTS

The prevalence of women is 4.26:1, the most frequent age at disease onset is 18-29 years (36% of cases). The laboratory aspects of the disease are characterized and approaches to the treatment and prevention of exacerbations of NMOSD in patients of the Russian population are evaluated. Approaches to diagnostics are compared depending on the applied diagnostic criteria (34% of patients do not meet neuromyelitis optica 2006 diagnostic criteria). A prognosis for the prevalence of NMOSD in the Russian population has been proposed: 0.45-4.21/100000.

CONCLUSION

This is the first published data on clinical and epidemiological characteristics of NMOSD in the Russian Federation.

Comparisons of clinical phenotype, radiological and laboratory features, and therapy of neuromyelitis optica spectrum disorder by regions: update and challenges

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) associated with autoantibody (ab) to aquaporin-4 (AQP4). There is obvious variation between regions and countries in the epidemiology, clinical features and management in NMOSD. Based on published population-based observation and cohort studies, the different clinical pattern of NMOSD has been seen in several geographical regions and some of these patients with NMOSD-like features do not fully meet the current diagnostic criteria, which is needed to consider the value of recently revised diagnostic criteria. At present, all treatments applied in NMOSD have made great progress, however, these treatments failed in AQP4 ab negative and refractory patients. Therefore, it is necessary to turn into an innovative idea and to open a new era of NMOSD treatment to develop novel and diverse targets and effective therapeutic drugs in NMOSD and to conduct the trails in large clinical samples and case-control studies to confirm their therapeutic effects on NMOSD in the future, which still remain a challenge.

Long-Term Safety and Efficacy of Eculizumab in Aquaporin-4 IgG-Positive NMOSD

OBJECTIVE

During PREVENT (NCT01892345), eculizumab significantly reduced relapse risk versus placebo in patients with aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder (AQP4-IgG+ NMOSD). We report an interim analysis of PREVENT's ongoing open-label extension (OLE; NCT02003144) evaluating eculizumab's long-term safety and efficacy.

METHODS

Patients who completed PREVENT could enroll in the OLE to receive eculizumab (maintenance dose = 1,200 mg/2 weeks, after a blinded induction phase). Safety and efficacy data from PREVENT and its OLE (interim data cut, July 31, 2019) were combined for this analysis.

RESULTS

Across PREVENT and the OLE, 137 patients received eculizumab and were monitored for a median (range) of 133.3 weeks (5.1-276.9 weeks), for a combined total of 362.3 patient-years (PY). Treatment-related adverse event (AE) and serious adverse event (SAE) rates were 183.5 in 100 PY and 8.6 in 100 PY, respectively. Serious infection rates were 10.2 in 100 PY in eculizumab-treated patients versus 15.1 in 100 PY in the PREVENT placebo group. No patient developed a meningococcal infection. At 192 weeks (3.7 years), 94.4% (95% confidence interval [CI], 88.6-97.3) of patients remained adjudicated relapse-free. The adjudicated annualized relapse rate was 0.025 (95% CI = 0.013-0.048) in all eculizumab-treated patients versus 0.350 (95% CI = 0.199-0.616) in the PREVENT placebo group. During the OLE, 37% of patients (44 of 119 patients) stopped or decreased background immunosuppressive therapy use.

INTERPRETATION

This analysis demonstrates that eculizumab's long-term safety profile in NMOSD is consistent with its established profile across other indications. This analysis also demonstrated the sustained ability of long-term eculizumab treatment to reduce relapse risk in patients with AQP4-IgG+ NMOSD. ANN NEUROL 2021;89:1088-1098.

Recent advances in the treatment of neuromyelitis optica spectrum disorders

PURPOSE OF REVIEW

This review examines recently published randomized placebo-controlled trials for the treatment of neuromyelitis optica spectrum disorders (NMOSD).

RECENT FINDINGS

Until recently, treatments for NMOSD were used-off label and had not been subjected to randomized placebo-controlled trials. Increased understanding of the pathophysiology of NMOSD, particularly aquaporin-4-IgG seropositive NMOSD, lead to the investigation of eculizumab, inebilizumab, and satralizumab for maintenance therapy. Eculizumab inhibits the cleavage of the terminal complement protein C5, inebilizumab depletes immune cells of B-lymphocyte lineage, and satralizumab inhibits interleukin-6 receptors. International, phase 3, randomized, placebo-controlled trials have demonstrated that each of these therapies reduces the risk of NMOSD relapse. In some cases, the studied therapies were administered in conjunction with other immunosuppressants. Each therapy has important safety considerations, notably risk of meningococcal infection with eculizumab and risks of infection and hypogammaglobulinemia with inebilizumab. Reviewing trial design highlights future areas of inquiry for the treatment of NMOSD.

SUMMARY

Eculizumab, inebilizumab, and satralizumab are effective maintenance therapies approved for the treatment of AQP-4 seropositive NMOSD.

Eculizumab in Asian patients with anti-aquaporin-IgG-positive neuromyelitis optica spectrum disorder: A subgroup analysis from the randomized phase 3 PREVENT trial and its open-label extension

Background Eculizumab, a terminal complement inhibitor, significantly reduced the risk of relapse compared with placebo in patients with anti-aquaporin-4 immunoglobulin G-positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD) in the PREVENT trial. We report efficacy and safety analyses in Asian patients in PREVENT and its open-label extension (OLE). Methods PREVENT was a double-blind, randomized, phase 3 trial. Patients with AQP4+ NMOSD were randomly assigned (2:1) to receive intravenous eculizumab (maintenance dose, 1200 mg/2 weeks) or placebo. Patients who completed PREVENT could receive eculizumab in an OLE. Analyses were performed in a prespecified subgroup of Asian patients. Results Of 143 patients enrolled, 52 (36.4%) were included in the Asian subgroup (eculizumab, n = 37; placebo, n = 15); 45 Asian patients received eculizumab in the OLE. Most Asian patients (86.5%) received concomitant immunosuppressive therapy. During PREVENT, one adjudicated relapse occurred in patients receiving eculizumab and six occurred in patients receiving placebo in the Asian subgroup (hazard ratio, 0.05; 95% confidence interval: 0.01-0.35; p = 0.0002). An estimated 95.2% of Asian patients remained relapse-free after 144 weeks of eculizumab treatment. Upper respiratory tract infections, headache, and nasopharyngitis were the most common adverse events with eculizumab in the Asian subgroup. Conclusion Eculizumab reduces the risk of relapse in Asian patients with AQP4+ NMOSD, with a benefit-risk profile similar to the overall PREVENT population. The benefits of eculizumab were maintained during long-term therapy. Clinical trial registration ClinicalTrials.gov identifiers: NCT01892345 (PREVENT); NCT02003144 (open-label extension).