Network Meta-analysis of Food and Drug Administration-approved Treatment Options for Adults with Aquaporin-4 Immunoglobulin G-positive Neuromyelitis Optica Spectrum Disorder

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 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.

Research hotspots and trends on neuromyelitis optica spectrum disorders: insights from bibliometric analysis

Neuromyelitis optica spectrum disorders (NMOSD) are demyelinating diseases of the central nervous system, have drawn the attention of many researchers due to the relapsing courses and cumulative disability. A first bibliometric analysis of NMOSD was conducted to identify the research hotspots and emerging trends. Articles relevant to NMOSD published in the core collection of Web of Science were retrieved and analyzed through visualized analysis using CiteSpace and VOSviewer, focusing on annual publication trends, countries, institutions, authors, journals, and keywords. The analysis showed that over the past 30 years, publications related to NMOSD had shown steady growth with slight fluctuations. The United States played an important part in this field, with the highest outputs and the greatest number of citations. Research hotspots of NMOSD had gradually shifted from the definition, biomarkers, and diagnostic criteria to diagnosis and treatment, particularly immunotherapy. This bibliometric analysis provides researchers with a theoretical basis for studying NMOSD and offers guidance for future research directions.

Efficacy and safety of monoclonal antibody therapy in patients with neuromyelitis optica spectrum disorder: A systematic review and network meta-analysis

Introduction

Neuromyelitis optica spectrum disorder (NMOSD) is a devastating inflammatory CNS demyelinating disease. Two groups of monoclonal antibodies (mAbs) are used to prevent disease relapse, i.e., Food and Drug Administration (FDA)-approved mAbs (e.g., eculizumab satralizumab, inebilizumab), and off-label mAb drugs (e.g., rituximab and tocilizumab). The FDA-approved mAbs have high efficacy but more expensive compared to the off-labels, and thus are less accessible. This systematic review and network meta-analysis (NMA) was to assess the efficacy and safety of both classes of mAbs compared to the current standard treatments.

Methods

Systematically searches were conducted in MEDLINE and SCOPUS from inception until July 2021. Randomized-controlled trials (RCTs) were eligible if they compared any pair of treatments (mAbs, immunosuppressive drugs, or placebo) in adult patients with NMOSD. Studies with AQP4-IgG positive or negative were used in the analysis. Probability of relapse and time to event were extracted from the Kaplan-Meier curves using Digitizer. These data were then converted into individual patient time-to-event data. A one-stage mixed-effect survival model was applied to estimate the median time to relapse and relative treatment effects using hazard ratios (HR). Two-stage NMA was used to determine post-treatment annualized relapse rate (ARR), expanded disability status score (EDSS) change, and serious adverse events (SAE). Risk of bias was assessed using the revised cochrane risk of bias tool.

Results

A total of 7 RCTs with 776 patients were eligible in the NMA. Five of the seven studies were rated low risk of bias. Both FDA-approved and off-label mAbs showed significantly lower risk of relapse than standard treatments, with HR (95% CI) of 0.13 (0.07, 0.24) and 0.16 (0.07, 0.37) respectively. In addition, the FDA-approved mAbs had 20% lower risk of relapse than the off-label mAbs, but this did not reach statistical significance. The ARRs were also lower in FDA-approved and off-label mAbs than the standard treatments with the mean-difference of−0.27 (-0.37,−0.16) and−0.31(-0.46,−0.16), respectively.

Conclusion

The off-label mAbs may be used as the first-line treatment for improving clinical outcomes including disease relapse, ARR, and SAEs for NMOSD in countries where resources and accessibility of the FDA-approved mAbs are limited.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=283424, identifier: CRD42021283424.

An update on biologic treatments for neuromyelitis optica spectrum disorder

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the central nervous system mediated by antibodies targeting the aquaporin-4 (AQP4) water channel expressed on astrocytes. The binding of specific antibodies to AQP4 causes complement-dependent cytotoxicity, leading to inflammation and demyelination. Several recent phase 2 and 3 randomized placebo-controlled trials showed the efficacy and safety of monoclonal antibody therapies targeting B-cells, interleukin-6 receptor, and complement.

AREAS COVERED

Current biologic treatments for NMOSD and developments therein, and unresolved issues in NMOSD treatment.

EXPERT OPINION

New biologic treatments demonstrate high efficacy and good safety for patients with AQP4-IgG-positive NMOSD. The optimal therapeutics for seronegative NMOSD, pediatric patients, and female patients who are pregnant or wish to be are unclear, and further research is needed. Also, real-world studies of new biological agents and the data on the durability of their beneficial effects and their long-term safety are required. Effective rescue therapy for an acute attack is critical given permanent disability in NMOSD is attack-related, and biologic agents that treat acute attack are emerging. If such treatments are to become widely applied, studies on the most cost-effective treatment strategies are needed.

Inebilizumab: A Review in Neuromyelitis Optica Spectrum Disorder

Inebilizumab (Uplizna®) is a recently approved monoclonal antibody for use in adults with neuromyelitis optica spectrum disorder (NMOSD) who are anti-aquaporin-4 (AQP4) antibody seropositive. Inebilizumab targets the B cell antigen CD19 and effectively depletes circulating B cells, thus suppressing inflammatory NMOSD attacks that are potentially disabling or life-threatening. It is approved as an intravenous infusion in several countries. In the pivotal phase 2/3 N-MOmentum trial, inebilizumab reduced the risk of NMOSD attacks compared with placebo, including in AQP4-antibody seropositive patients. Inebilizumab also significantly reduced the risk of disability score worsening, the number of NMOSD-related hospitalisations and MRI lesion count, but had no significant effect on low-contrast binocular vision. The treatment effect on relapse risk and disability scores was sustained in inebilizumab-treated patients for ≥ 4 years during the open-label extension. Inebilizumab was generally well tolerated, with the most common adverse events being urinary tract infection and arthralgia. Thus, inebilizumab is an effective treatment option for adults with AQP4-antibody seropositive NMOSD.

Serum glial fibrillary acidic protein correlates with retinal structural damage in aquaporin-4 antibody positive neuromyelitis optica spectrum disorder

BACKGROUND

Aquaporin-4 immunoglobulin-G positive (AQP4-IgG⁺) neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune astrocytopathy associated with optic neuritis (ON). Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an oligodendrocytopathy with a similar phenotype. Serum glial fibrillary acidic protein (sGFAP), an astrocyte-derived protein, is associated with disease severity in AQP4-IgG⁺ NMOSD. Serum neurofilament light (sNfL) indicates neuroaxonal damage. The objective was to investigate the association of sGFAP and sNfL with subclinical afferent visual system damage in clinically stable AQP4-IgG⁺ NMOSD and MOGAD patients.

METHODS

In this cross-sectional study, clinically stable patients with AQP4-IgG⁺ NMOSD (N = 33) and MOGAD (N = 16), as diseased controls, underwent sGFAP and sNfL measurements by single molecule array, retinal optical coherence tomography and visually evoked potentials.

RESULTS

Higher sGFAP concentrations were associated with thinner ganglion cell-inner plexiform layer (β (95% confidence interval (CI)) = -0.75 (-1.23 to -0.27), p = 0.007) and shallower fovea (average pit depth: β (95%CI) = -0.59 (-0.63 to -0.55), p = 0.020) in NMOSD non-ON eyes. Participants with pathological P100 latency had higher sGFAP (median [interquartile range]: 131.32 [81.10-179.34] vs. 89.50 [53.46-121.91] pg/ml, p = 0.024). In MOGAD, sGFAP was not associated with retinal structural or visual functional measures.

CONCLUSIONS

The association of sGFAP with structural and functional markers of afferent visual system damage in absence of ON suggests that sGFAP may be a sensitive biomarker for chronic disease severity in clinically stable AQP4-IgG⁺ NMOSD.

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.

Neuromyelitis Optica Spectrum Disorder: From Basic Research to Clinical Perspectives

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system characterized by relapses and autoimmunity caused by antibodies against the astrocyte water channel protein aquaporin-4. Over the past decade, there have been significant advances in the biologic knowledge of NMOSD, which resulted in the IDENTIFICATION of variable disease phenotypes, biomarkers, and complex inflammatory cascades involved in disease pathogenesis. Ongoing clinical trials are looking at new treatments targeting NMOSD relapses. This review aims to provide an update on recent studies regarding issues related to NMOSD, including the pathophysiology of the disease, the potential use of serum and cerebrospinal fluid cytokines as disease biomarkers, the clinical utilization of ocular coherence tomography, and the comparison of different animal models of 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.

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.

Evaluating the Economic Burden of Relapses in Neuromyelitis Optica Spectrum Disorder: A Real-World Analysis Using German Claims Data

Introduction

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the central nervous system which causes recurrent relapses, resulting in blindness, paralysis, and spinal cord damage. This study sought to explore the real-world burden, treatment, and cost of NMOSD in Germany using claims data.

Methods

Our study consisted of a retrospective analysis of two anonymized health insurance datasets covering around 9 million patients in Germany from 01/01/2013 to 31/12/2019. NMOSD patients were identified using inpatient and outpatient International Classification of Diseases, Tenth Revision (ICD-10) diagnoses of neuromyelitis optica (NMO; G36.0) and relevant symptom codes. Active periods of disease were identified based on relapse events (including hospitalizations and acute treatment); healthcare resource utilization (HCRU) and direct costs were allocated to active and inactive periods based on treatment dates. Propensity score matching was used to compare HCRU and cost outcomes among patients with and without NMOSD.

Results

Overall, 130 patients were identified as having NMOSD (mean age: 46.84 years; 58% female). NMOSD patients recorded 16.52 active and 348.48 inactive days per patient year (PPY). HCRU and associated costs were approximately tenfold higher during active periods than during inactive periods, with the largest share of the cost difference driven by hospitalizations (€6424.09/€259.10 per active/inactive month) and outpatient drug prescriptions (€412.83/€271.58). Direct healthcare costs incurred by patients with NMOSD (€12,913.28 PPY) were approximately threefold higher than those incurred by patients without NMOSD (€4667.66 PPY). Costs of hospitalization (€6448.32/€1937.64 PPY) and outpatient prescriptions (€3335.67/€1037.64 PPY) contributed most strongly to the difference.

Conclusion

Patients with NMOSD consume substantial healthcare resources and incur heavy costs during active disease phases. This study captured direct measurable healthcare costs and likely underestimates the real societal/emotional burden on patients and their families. Nevertheless, prevention of acute relapses represents one compelling strategy to minimize the economic burden of NMOSD in Germany.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00311-x.