Emerging drugs for the treatment of neuromyelitis optica

Frequency of new asymptomatic MRI lesions during attacks and follow-up of patients with NMOSD in a real-world setting

BACKGROUND

We aimed to assess the frequency of new asymptomatic lesions on brain and spinal imaging (magnetic resonance imaging (MRI)) and their association with subsequent relapses in a large cohort of neuromyelitis optica spectrum disorder (NMOSD) patients in Argentina.

METHODS

We retrospectively reviewed 675 MRI (225 performed during an attack and 450 during the relapse-free period (performed at least 3 months from the last attack)) of NMOSD patients who had at least 2 years of clinical and MRI follow-up since disease onset. Kaplan-Meier (KM) curves were used for depicting time from remission MRI to subsequent relapse.

RESULTS

We included 135 NMOSD patients (64.4% were aquaporin-4-immunoglobulin G (AQP4-IgG)-positive). We found that 26 (19.26%) and 66 (48.88%) of patients experienced at least one new asymptomatic MRI lesion during both the relapse-free period and attacks, respectively. The most frequent asymptomatic MRI lesions were optic nerves followed by short-segment myelitis during the relapse-free period and attacks. KM curves did not show differences in the time taken to develop a new relapse.

CONCLUSION

Our findings showed that new asymptomatic lesions are relatively frequent. However, the presence of new asymptomatic MRI lesions during the relapse-free period and at relapses was not associated with a shorter time to developing subsequent relapses.

Glial fibrillary acidic protein as a biomarker in neuromyelitis optica spectrum disorder: a current review

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing, often debilitating neuroinflammatory disease, whose predominant clinical manifestations are longitudinally extensive transverse myelitis and optic neuritis. About 80% of the patients with an NMOSD phenotype have pathogenic autoantibodies against the astrocyte water channel aquaporin-4 (AQP4-IgG). While therapeutic options for NMOSD have greatly expanded in recent years, well-established biomarkers for prognosis or treatment response are still lacking. Glial fibrillary acidic protein (GFAP) is mainly expressed in astrocytes and can be detected in cerebrospinal fluid (CSF) and blood of patients with NMOSD.

AREAS COVERED

Here, we comprehensively review the current knowledge on GFAP as a biomarker in NMOSD.

EXPERT OPINION

In patients with AQP4-IgG⁺ NMOSD, GFAP levels are elevated in CSF and serum during acute attacks and correlate with disability, consistent with the pathophysiology of this antibody-mediated astrocytopathy. Serum GFAP levels tend to be higher in AQP4-IgG⁺ NMOSD than in its differential diagnoses, multiple sclerosis, and myelin oligodendrocyte antibody-associated disease. Importantly, serum GFAP levels in AQP4-IgG⁺ NMOSD during remission may be predictive of future disease activity. Serial serum GFAP measurements are emerging as a biomarker to monitor disease activity in AQP4-IgG⁺ NMOSD and could have the potential for application in clinical practice.

Diagnostik der Neuromyelitis-optica-Spektrum-Erkrankung (NMOSD) und der MOG-Antikörper-assoziierten Erkrankung (MOGAD)

Die Aquaporin-4-Antikörper-positive Neuromyelitis-optica-Spektrum-Erkrankung (engl. NMOSD) und die Myelin-Oligodendrozyten-Glykoprotein-Antikörper-assoziierte Erkrankung (engl. MOGAD) sind Autoimmunerkrankungen des zentralen Nervensystems. Typische Erstmanifestationen sind bei Erwachsenen Optikusneuritis und Myelitis. Eine Beteiligung auch von Hirn und Hirnstamm, spätestens im weiteren Verlauf, ist häufig. Während die NMOSD nahezu immer schubförmig verläuft, nimmt die MOGAD gelegentlich einen monophasischen Verlauf. Die Differenzialdiagnostik ist anspruchsvoll und stützt sich auf u. a. auf radiologische und serologische Befunde. Die Abgrenzung von der häufigeren neuroinflammatorischen Erkrankung, Multiple Sklerose (MS), ist von erheblicher Bedeutung, da sich Behandlung und langfristige Prognose von NMOSD, MOGAD und MS wesentlich unterscheiden. Die vielfältigen Symptome und die umfangreiche Diagnostik machen eine enge Zusammenarbeit zwischen Ophthalmologie, Neurologie und Radiologie erforderlich. Dieser Artikel gibt einen Überblick über typische MRT-Befunde und die serologische Antikörperdiagnostik bei NMOSD und MOGAD. Zwei illustrative Fallberichte aus der ärztlichen Praxis ergänzen die Darstellung.

Telitacicept following plasma exchange in the treatment of subjects with recurrent neuromyelitis optica spectrum disorders: A single‐center, single‐arm, open‐label study

Introduction

Neuromyelitis optica spectrum disorders (NMOSD), mainly mediated by B cells and AQP4 antibody, has a high rate of recurrence. Telitacicept is a novel drug specifically targeting the upstream signaling for the activation of B cell with its following production of autoimmune antibodies. Thus, it may be a promising approach. Our study preliminarily explored the potential safety and effectiveness of Telitacicept following plasma exchange in the treatment of recurrent NMOSD.

Methods

This was a single‐center, single‐arm, open‐label study enrolling eight patients with recurrent NMOSD in China. All patients received plasma exchange three times, followed by Telitacicept 240 mg every week for 46 times. The primary endpoint was the time of first recurrence after enrollment. Secondary end points included: changes in Expanded Disability Status Scale score, Optic Spinal Impairment Scale score, Hauser Ambulation Index, number of lesions on MRI, retinal nerve fiber layer thickness measured by optical coherence tomography, latency and amplitude of visual evoked potential, titer of AQP4 antibody, and immune parameters of blood. Safety was also assessed. The study was registered with Chictr.org.cn (ChiCTR1800019427).

Results

Eight eligible patients were enrolled. Relapse occurred in two patients (25%) and five patients (63%) remained relapse free after 48 weeks of treatment. The time to first recurrence was prolonged and the number of recurrences was reduced (p < 0.001, power of test = 1). One patient withdrew from the study due to low neutrophil count. No serious adverse events occurred.

Conclusions

In this small, uncontrolled study, Telitacicept following plasma exchange has the potential to be a safe treatment for patients with recurrent NMOSD. It may prolong the recurrence interval and reduces the annual count of recurrences. A multicenter randomized controlled study with a larger sample is thus feasible and needed to further assess its safety and efficacy.

Results of a Survey on Diagnostic Procedures and Treatment Choices for Neuromyelitis Optica Spectrum Disorder in Korea: Beyond the Context of Current Clinical Guidelines

Background and Purpose

Neuromyelitis optica spectrum disorder (NMOSD) is a rare demyelinating disease of the central nervous system (CNS). We investigated the medical behaviors of experts in Korea when they are diagnosing and treating NMOSD.

Methods

An anonymous questionnaire on the diagnosis and treatment of NMOSD was distributed to experts in CNS demyelinating diseases.

Results

Most respondents used the 2015 diagnostic criteria for NMOSD and applied a cerebrospinal fluid examination, magnetic resonance imaging (MRI) of the brain and spine, and anti-aquaporin-4 antibody testing to all suspected cases of NMOSD. All respondents prescribed steroid pulse therapy as an first-line therapy in the acute phase of NMOSD, and 67% prescribed azathioprine for maintenance therapy in NMOSD. However, details regarding monitoring, the tapering period of oral steroids, second-line therapy use in refractory cases, management during pregnancy, and schedule of follow-up MRI differed according to the circumstances of individual patients. We analyzed the differences in response rates between two groups of respondents according to the annual number of NMOSD patients that they treated. The group that had been treating ≥10 NMOSD patients annually preferred rituximab more often as the second-line therapy (p=0.011) and had more experience with rituximab treatment (p=0.015) compared with the group that had been treating <10 NMOSD patients.

Conclusions

This study has revealed that NMOSD experts in Korea principally follow the available treatment guidelines. However, the differences in specific clinical practices applied to uncertain cases that have been revealed will need to be investigated further in order to formulate suitable recommendations.

Next generation antibody-based therapies in neurology

Antibody (Ab)-based therapeutics are now standard in the treatment of neuroinflammatory diseases, and the spectrum of neurological diseases targeted by those approaches continues to grow. The efficacy of Ab-based drug-platforms is largely determined by the specificity-conferring antigen-binding fragment (Fab) and the crystallizable fragment (Fc) driving antibody function. The latter provides specific instructions to the immune system by interacting with cellular Fc receptors and complement components. Extensive engineering efforts enabled tuning of Fc functions to modulate effector functions and to prolong or reduce Ab serum half-lives. Technologies that improve bioavailability of Ab-based treatment platforms within the central nervous system parenchyma are being developed and could invigorate drug discovery for a number of brain diseases for which current therapeutic options are limited. These powerful approaches are currently being tested in clinical trials or have been successfully translated into the clinic. Here, we review recent developments in the design and implementation of Ab-based treatment modalities in neurological diseases.

Evaluation of effect of empirical attack-preventive immunotherapies in neuromyelitis optica spectrum disorders: An update systematic review and meta -analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system, which mainly involves the optic nerve and spinal cord. Frequent relapse can accumulate the degree of disability. At present, the main treatment options are immunosuppressants and blood purification. The first-line immunosuppressants for NMOSD are mainly rituximab (RTX), mycophenolate mofetil (MMF) and azathioprine (AZA). Therefore, we designed this systematic review and meta-analysis to evaluate the safety and effect of the above three drugs in the treatment of NMOSD patients.

METHODS

The following Medical Subject Heading (MeSH) and related entry terms are used to search English literature in PubMed, MEDLINE and CENTRAL databases, respectively. MeSH include: Neuromyelitis optic and Rituximab or Azathioprine or Mycophenolate Mofetil; entry terms include: NMO Spectrum Disorder, NMO Spectrum Disorders, Neuromyelitis Optica (NMO) Spectrum Disorder, Neuromyelitis Optica Spectrum Disorders, Devic Neuromyelitis Optica, Neuromyelitis Optica, Devic, Devic's Disease, Devic Syndrome, Devic's Neuromyelitis Optica, Neuromyelitis Optica (NMO) Spectrum Disorders, CD20 Antibody, Rituximab CD20 Antibody, Mabthera, IDEC-C2B8 Antibody, GP2013, Rituxan, Mycophenolate Mofetil, Mofetil, Mycophenolate, Mycophenolic Acid, Morpholinoethyl Ester, Cellcept, Mycophenolate Sodium, Myfortic, Mycophenolate Mofetil Hydrochloride, Mofetil Hydrochloride, Mycophenolate, RS 61443, RS-61443, RS61443, azathioprine sodium, azathioprine sulfate (note: literature retrieval operators "AND" "OR" "NOT" are used to link MeSH with Entry Terms.) The literature search found a total of 3058 articles about rituximab, mycophenolate mofetil and azathioprine in the treatment of NMOSD, 63 of which were included in this study after a series of screening.

RESULTS

930,933,732 patients with NMOSD were enrolled, who had been treated with MMF, AZA and RTX, respectively. The pooled standardized mean difference (SMD) of EDSS before and after RTX treated was -0.58 (95%CI: -0.72, -0.44) (I² = 0%, p = 0.477), before and after MMF treated was -0.47 (95%CI: -0.73, -0.21) (I² = 85.6%, p<0.001), before and after AZA treated was -0.41 (95%CI: -0.60, -0.23) (I² = 65.4%, p<0.001). there was no significant difference in the effect of the three drugs on reducing EDSS scores (RTX vs MMF, p = 0.522; RTX vs AZA, p = 0.214; MMF vs AZA, p = 0.732). The pooled standardized mean difference (SMD) of ARR before and after RTX treated was -1.45 (95%CI: -1.72, -1.18) (I² = 72.4%, p<0.001), before and after MMF treated was -1.14 (95%CI: -1.31, -0.97) (I² = 54.5%, p<0.001), before and after AZA treated was -1.11 (95%CI: -1.39, -0.83) (I² = 83.4%, p<0.001). RTX significantly reduced ARR compared with the other two drugs (RTX vs MMF, p = 0.039; RTX vs AZA, p = 0.049; MMF vs AZA, p = 0.436).

CONCLUSION

The results of this systematic review and meta-analysis showed that the treatment of NMOSD patients with RTX, MMF and AZA is associated with decreased number of relapses and disability improvement as well, and there was no significant difference in the effect of the three drugs on reducing EDSS scores, but RTX significantly reduced ARR compared with the other two drugs.

AQP4-IgG autoimmunity in Japan and Germany: Differences in clinical profiles and prognosis in seropositive neuromyelitis optica spectrum disorders

BACKGROUND

Clinical outcomes in neuromyelitis optica spectrum disorders (NMOSD) vary across different regions.

OBJECTIVE

To describe clinical profiles in Japanese and German NMOSD patients.

METHODS

Medical records of aquaporin-4-immunoglobulin G (AQP4-IgG) positive NMOSD patients from Japan (n = 54) and Germany (n = 38) were retrospectively analyzed.

RESULTS

The disability status was similar between both cohorts, although Japanese patients had a longer disease duration (13.3 ± 11.1 vs. 8.1 ± 6.9 years, p = 0.018) but similar relapse rates. Optic neuritis and myelitis were the most frequent attacks in both cohorts. Brain attacks occurred more frequently in Japanese patients (40.7% vs. 15.8%, p = 0.020). The time from disease onset (median [interquartile range] 2.3 [0.3-10.1] vs. 0.6 [0.2-1.9] years, p = 0.009) and the number of attacks (2.5 [1-7] vs. 2 [1-3], p = 0.047) until start of the first immunotherapy were higher in the Japanese cohort. Rituximab was the most common drug in the German cohort (52.6%) and not given in the Japanese cohort (p < 0.001), where oral prednisolone was the most common drug (92.6% vs. 15.8%, p < 0.001). The frequency of autoimmune comorbidities was higher in the German cohort (39.5% vs. 18.5%, p = 0.047).

CONCLUSION

Compared with Japanese NMOSD patients, German patients presented with similar disability despite shorter disease duration and earlier and more frequent immunosuppressive therapy.

[Treatment of antibody-mediated encephalomyelitis : Strategies for the treatment of neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease]

BACKGROUND

Antibody-mediated encephalomyelitis, such as neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and glial fibrillary acidic protein (GFAP) antibody-associated astrocytopathy belong to a group of newly described autoimmune diseases.

AIM

Presentation of the treatment of antibody-mediated encephalomyelitis with a focus on NMOSD and MOGAD.

METHODS

Selective literature search in PubMed taking the consultation version of the S2k guidelines of the German Society of Neurology (DGN) on the diagnosis and treatment of multiple sclerosis (MS), NMOSD and MOG IgG-associated diseases into account.

RESULTS

Acute relapses are treated with high-dose steroid pulse therapy or apheresis therapy (plasma exchange or immunoadsorption). It is crucial to start treatment as quickly as possible and apheresis therapy can also be used as first-line treatment under certain conditions. For prophylactic immunotherapy, steroids, classical immunosuppressants and monoclonal antibodies with specific mechanisms of action are used. Eculizumab, inebilizumab and satralizumab are the first drugs approved for NMOSD. Symptomatic treatment and neurorehabilitation are important complementary measures.

CONCLUSION

Treatment of antibody-mediated encephalomyelitis differs from treatment of multiple sclerosis and requires specific measures.

Telitacicept Following Plasma Exchange in the Treatment of Subjects With Recurrent NMOSD: Study Protocol for a Single-Center, Single-Arm, Open-Label Study

Background: Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune demyelinating disease that recurrently relapses and leads to severe disability. The available choices for disease prevention are few or intolerable. Previous studies suggested that telitacicept may provide a promising therapeutic strategy for autoimmune diseases involving B cells. Therefore, this study aims to assess the effectiveness and safety of telitacicept for recurrent NMOSD.

Methods: We will perform a single-arm, single-center, open-label, specialist study with a total enrollment of eight participants. The treatment regimen includes plasma exchange three times and subcutaneous injection of telitacicept for 46 cycles, with a total period of 48 weeks. The primary endpoint is the time to first recurrence after enrollment. Secondary endpoints are Expanded Disability Status Scale (EDSS) score, Opticospinal Impairment Scale (OSIS) score, Hauser Ambulation Index, number of lesions on MRI, and changes in visual evoked potential (VEP), optical coherence tomography (OCT) and immunologic status. All adverse events after medication will be documented and investigated.

Discussion: This study will explore the safety and effectiveness of telitacicept following plasma exchange regarding the time to recurrence in neuromyelitis optica spectrum disorder (NMOSD) for the first time.

Clinical Trial Registration:Chictr.org.cn, identifier ChiCTR1800019427

Anti-aquaporin 4 IgG Is Not Associated With Any Clinical Disease Characteristics in Neuromyelitis Optica Spectrum Disorder

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a clinically defined, inflammatory central nervous system (CNS) disease of unknown cause, associated with humoral autoimmune findings such as anti-aquaporin 4 (AQP4)-IgG. Recent clinical trials showed a benefit of anti-B cell and anti-complement-antibodies in NMOSD, suggesting relevance of anti-AQP4-IgG in disease pathogenesis. Objective: AQP4-IgG in NMOSD is clearly defined, yet up to 40% of the patients are negative for AQP4-IgG. This may indicate that AQP4-IgG is not disease-driving in NMOSD or defines a distinct patient endotype. Methods: We established a biobank of 63 clinically well-characterized NMOSD patients with an extensive annotation of 351 symptoms, patient characteristics, laboratory results and clinical scores. We used phylogenetic clustering, heatmaps, principal component and longitudinal causal interference analyses to test for the relevance of anti-AQP4-IgG. Results: Anti-AQP4-IgG was undetectable in 29 (46%) of the 63 NMOSD patients. Within anti-AQP4-IgG-positive patients, anti-AQP4-IgG titers did not correlate with clinical disease activity. Comparing anti-AQP4-IgG-positive vs. -negative patients did not delineate any clinically defined subgroup. However, anti-AQP4-IgG positive patients had a significantly (p = 0.022) higher rate of additional autoimmune diagnoses. Conclusion: Our results challenge the assumption that anti-AQP4-IgG alone plays a disease-driving role in NMOSD. Anti-AQP4-IgG might represent an epiphenomenon associated with NMOSD, may represent one of several immune mechanisms that collectively contribute to the pathogenesis of this disease or indeed, anti-AQP4-IgG might be the relevant factor in only a subgroup of patients.

Satralizumab in the treatment of neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare and debilitating autoimmune astrocytopathy with a predominantly relapsing disease course. Satralizumab, a humanized monoclonal antibody, was designed to treat NMOSD by targeting the IL-6 receptor. Satralizumab builds on positive experiences of off-label use tocilizumab in recent years. Before 2019, no medications were approved for the treatment of NMOSD. In 2020, satralizumab became the third compound to enter the US market, adding to the complement inhibitor eculizumab and the CD19 inhibitor inebilizumab. Here, we review the two randomized, double-blind, Phase III trials that investigated the subcutaneous administration of satralizumab as add-on treatment and monotherapy. Both studies revealed positive effects concerning the reduction of relapse risk for AQP4 seropositive NMOSD patients and generally good tolerability.

Review of approved NMO therapies based on mechanism of action, efficacy and long-term effects

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Neuromyelitis optica (NMO - including NMO spectrum disorders [NMOSD]) is a devastating disease.

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Up until recently, there was no proven agent to treat to prevent relapses.

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We now have three agents indicated for the treatment of NMO.

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We might suggest the following sequence – 1st line using eculizumab for rapid efficacy and stabilization without effect on the acquired immune system followed by satrilizumab (long term immunomodulation).

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Reserve inebilizumab (immunosuppressant) for breakthrough disease and salvage the severe with AHSCBMT.

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In NMO, control the complement, transition to modulation, and reserve suppression – and salvage the severe with AHSCBMT.

Importance

Neuromyelitis optica (NMO - including NMO spectrum disorders [NMOSD]) is a devastating disease. Eighty-three percent of patients with transverse myelitic (TM) attacks and 67% of patients with optic neuritis (ON) attacks have no or a partial recovery.

Observations

Up until recently, there was no proven agent to treat to prevent relapses. The neuro-immunological community had a dearth of indicated agents for NMOSD. We now have three agents indicated for the treatment of NMO including (eculizumab [Soliris®]), an anti-C5 complement inhibitor, satralizumab (ENSRYNG®), a monoclonal antibody against the IL-6 receptor (IL-6R) that blocks B cell antibody production and inebilizumab (Uplinza®), a monoclonal antibody that binds to the B-cell surface antigen CD19 with subsequent B and plasmablast cell lymphocytolysis with decreasing antibody production. Autologous hematopoietic stem cell bone marrow transplantation (AHSCBMT) has also been used. How do we sequence NMO therapies with the understanding of the acuteness and severity of the disease, the individual mechanism of action (MOA) and rapidity of onset of action, onset of efficacy and long-term safety of each agent?

Conclusions and Relevance

We might suggest the following sequence – 1st line using eculizumab for rapid efficacy and stabilization without effect on the acquired immune system followed by satrilizumab (long term immunomodulation). Reserve inebilizumab (immunosuppressant) for breakthrough disease and salvage the severe with AHSCBMT. In NMO, control the complement, transition to modulation, and reserve suppression – and salvage the severe with AHSCBMT.