RARE DISEASE
Neuromyelitis optica spectrum disorder
Neuromyelitis optica spectrum disorder
Neuromyelitis optica spectrum disorder
Synonyms: Devic disease, NMOSD
Synonyms: Devic disease, NMOSD
Synonyms: Devic disease, NMOSD
Drug discovery
10
drugs
With orphan designations
Overview
Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare autoimmune condition primarily targeting aquaporin-4 (AQP4) water channels in the central nervous system, causing optic neuritis, transverse myelitis, and brainstem syndromes. It leads to severe disability through relapses, with symptoms such as vision loss, paralysis, and autonomic dysfunction. Diagnosis requires MRI and AQP4-IgG serology, distinguishing it from multiple sclerosis. Early immunosuppression is critical to limit attack severity and relapse frequency.
Population
Prevalence: 1–12.99/100,000, with higher rates in Black (12.99) and Asian (9.41) populations vs. White individuals (5.58) [2][10].
Demographics: 90% female predominance; median age of onset ~40 years (AQP4-IgG+), earlier in non-White groups [1][10][14].
Comorbidities: Often linked with systemic autoimmune diseases (e.g., lupus, Sjögren’s) [9][14].
Burden
Disability: ≥65% of relapses require hospitalization; 15.4% mortality in Black vs. 7% overall [10][11].
Economic impact: High costs from recurrent hospitalizations, biologics, and long-term care [4][15].
Quality of life: Chronic pain, vision loss, and mobility deficits contribute to depression and unemployment [4][13].
Therapies
Acute attacks: High-dose IV corticosteroids ± plasma exchange (PLEX) for refractory cases [3][7].
Relapse prevention: First-line immunosuppressants (rituximab, mycophenolate mofetil) and FDA-approved biologics (eculizumab, inebilizumab, satralizumab) targeting complement, CD19/20, or IL-6 pathways [3][15].
Monitoring: Regular clinical/MRI assessments to adjust therapy and detect subclinical activity [7][15].
Categories: rare neurological diseases, rare ophthalmic disorders
Research Papers
1,823 drug discovery papers about Neuromyelitis optica spectrum disorder, with 5 first-in-class and 17 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
1,823 drug discovery papers about Neuromyelitis optica spectrum disorder, with 5 first-in-class and 17 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
2026-08-12 | Case Report: Pharmacological decision-making in pregnant women with neuromyelitis optica spectrum disorder: two contrasting clinical scenarios.
Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune disease of the central nervous system that predominantly affects women of reproductive age. Pregnancy requires careful pharmacological decision-making because maternal relapse can lead to severe neurological disability, while fetal exposure to immunosuppressive therapy remains an important safety concern. We report two contrasting clinical scenarios in pregnant women with NMOSD. Case 1 involved a 30-year-old primigravida with AQP4-IgG-negative NMOSD and weak isolated MOG-IgA positivity of uncertain clinical significance. At 11 weeks of gestation, she developed a disabling relapse with severe bilateral lower-limb weakness, sensory disturbance, inability to walk independently, and urinary dysfunction. High-dose intravenous methylprednisolone led to partial recovery. After multidisciplinary counseling, she chose pregnancy termination at 18+3 weeks because of residual disability, concerns about fetal drug exposure, possible need for further immunosuppression, and anticipated rehabilitation burden. Case 2 involved a 35-year-old primigravida with AQP4-IgG-positive NMOSD who had been clinically stable for approximately 1 year before conception while receiving prednisolone 10 mg/day and azathioprine 50 mg/day. This regimen was continued during pregnancy with neurological, obstetric, and clinical pharmacology monitoring. She remained relapse-free and delivered a healthy female infant at 38 weeks. The infant weighed 3,100 g, had Apgar scores of 10, 10, and 10 at 1, 5, and 10 min, and showed normal growth and development at 12 months. These cases are not directly comparable and cannot establish treatment efficacy or pregnancy outcome causality. They highlight the need for preconception counseling, individualized risk-benefit assessment, careful use of pregnancy-compatible maintenance therapy when clinically indicated, and multidisciplinary follow-up. Isolated weak MOG-IgA positivity requires cautious interpretation.
2026-08-12 | Clinical Use of Interleukin-6 Blockade in Neuroimmunological Disorders.
Interleukin-6 (IL-6) is a multifunctional cytokine that plays a critical role in immune regulation, host defense, and tissue repair. Within the central nervous system (CNS), IL-6 contributes to both neuroprotection and neuroinflammation, depending on the signaling pathway involved; classic signaling, trans-signaling, or trans-presentation. Dysregulation of IL-6, particularly through sustained overexpression, disrupts the blood-brain barrier (BBB) integrity, promotes glial activation, and amplifies chronic inflammation, thereby contributing to the pathophysiology of numerous neurological disorders. This review aims to evaluate the role of IL-6 in neuroinflammatory processes and its clinical implications across a spectrum of neurological diseases. It focuses on the therapeutic potential and safety profile of IL-6 inhibitors, particularly tocilizumab and satralizumab. Key conditions discussed include neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein-associated disease (MOGAD), autoimmune encephalitis (AE), neuro-Behçet's disease (NBD), myasthenia gravis (MG), epilepsy, multiple sclerosis (MS), and Alzheimer's disease (AD). Clinical trials have demonstrated the efficacy of IL-6 receptor blockade in reducing relapse rates in NMOSD, leading to regulatory approvals. Promising off-label results have also been reported in treatment-resistant cases of MOGAD, epilepsy, and autoimmune conditions. However, IL-6 inhibition carries risks such as serious infections and paradoxical inflammatory reactions. Targeting the IL-6 pathway represents a significant advancement in neuroimmunology, offering new therapeutic opportunities for otherwise refractory conditions. Future research should focus on large-scale randomized controlled trials and the development of IL-6 inhibitors capable of crossing the BBB to enhance CNS-specific efficacy. Cost-related accessibility also remains a major challenge for broader clinical application.
2026-08-11 | Obinutuzumab β for aquaporin-4-positive neuromyelitis optica spectrum disorder: a phase 3 randomized controlled trial.
Although CD20-directed B cell depletion has long been used in neuromyelitis optica spectrum disorder (NMOSD), high-quality, large-scale, randomized controlled trials remain limited. In this multicenter, randomized, double-blind phase 3 trial, we evaluated obinutuzumab β (MIL62), a novel glycoengineered type II anti-CD20 monoclonal antibody, in patients with NMOSD. Eligible participants aged 18-70 years with aquaporin-4-immunoglobulin G (AQP4-IgG)-seropositive NMOSD and an Expanded Disability Status Scale (EDSS) score of 7.0 or lower were randomly assigned (1:1) to receive intravenous obinutuzumab β 1,000 mg (n = 45) or placebo (n = 46). The primary outcome-time to first adjudicated relapse on or before week 52-was met: relapse occurred in two of 45 (4.4%) obinutuzumab β-treated participants and in 21 of 46 (45.7%) placebo-treated participants (hazard ratio = 0.069, 95% confidence interval: 0.016-0.296, P < 0.0001). The incidence of grade 3 or higher treatment-related adverse events was similar between the obinutuzumab β group (6.7%) and the placebo group (6.5%). These findings support obinutuzumab β as a glycoengineered type II anti-CD20 therapeutic option for patients with AQP4-IgG+ NMOSD. ClinicalTrials.gov identifier: NCT05314010 .
2026-08-08 | Complement C3 inhibitory peptide AMY-101 ameliorates brain injury in a mouse model of NMOSD.
Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory demyelinating disease of the central nervous system, clinically characterized primarily by optic neuritis and transverse myelitis. This study aimed to investigate the therapeutic potential of the complement C3 inhibitory peptide AMY-101 in experimental models of NMOSD. In vitro experiments were performed using AQP4-transfected cells exposed to AQP4-IgG and human complement to assess complement-dependent cytotoxicity and membrane attack complex (MAC) deposition. In vivo efficacy was evaluated in an intracerebral injection mouse model of NMOSD, in which histopathological changes after AMY-101 treatment were compared with those in untreated controls. AMY-101 significantly attenuated AQP4-IgG- and complement-mediated cytotoxicity and inhibited MAC formation in vitro. In the NMOSD mouse model, AMY-101 treatment markedly reduced astrocyte loss, AQP4 depletion, and demyelination compared with controls. These findings demonstrate that complement C3 inhibition with AMY-101 effectively ameliorates key pathological features of NMOSD in experimental models, supporting its potential as a therapeutic strategy and providing a rationale for further preclinical and clinical investigation.
2026-08-05 | Association of therapeutic plasma exchange with functional outcomes in selected neurological disorders: a retrospective cohort study from a single tertiary center in Saudi Arabia.
Neurological disorders are associated with considerable morbidity and healthcare impact. Therapeutic plasma exchange (TPE) is an intervention that removes pathogenic antibodies, immune complexes, and other plasma constituents from circulation. Previous studies have suggested that TPE could be associated with improved outcomes in selected neurological disorders. To evaluate functional outcomes following therapeutic plasma exchange in patients with selected neurological disorders at National Guard Health Affairs (NGHA) in Jeddah, Saudi Arabia. This retrospective cohort study analyzes 133 patients diagnosed with various neurological disorders who received TPE between August 2015 and December 2022 at NGHA. Diagnoses included multiple sclerosis (MS), myasthenia gravis (MG), Guillain-Barré syndrome (GBS), neuromyelitis optica spectrum disorder (NMOSD), chronic inflammatory demyelinating polyneuropathy (CIDP), autoimmune encephalitis (AE), and other neurological conditions including amyotrophic lateral sclerosis (ALS), transverse myelitis, cerebellar ataxia, paraneoplastic neurologic syndrome, polymyositis, and central nervous system (CNS) infections. The effectiveness of TPE was assessed using the Modified Rankin Scale (mRS) before and 90 days following the final TPE session. Statistical analysis included Wilcoxon signed-rank tests and Mann-Whitney U test, with significance set at (p < 0.05). Significant improvements in mRS scores were observed following TPE for MS, MG, and GBS (all p < 0.001), as well as for NMOSD (p = 0.008), CIDP (p = 0.007), and AE (p = 0.018), but not in other neurological disorders (p = 0.234). Overall mortality was 6.8%, with no TPE-related deaths. Comorbidities among deceased patients included hypertension, diabetes mellitus, malignancy, chronic kidney disease, and cardiovascular disease. TPE was associated with improved functional outcomes in selected neurological disorders. Comorbidities were common among patients with poorer outcomes. Due to the retrospective design and potential confounding factors, causal inferences cannot be established. Further prospective studies are warranted to evaluate the role of TPE and optimize patient selection.
2026-08-12 | Case Report: Pharmacological decision-making in pregnant women with neuromyelitis optica spectrum disorder: two contrasting clinical scenarios.
Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune disease of the central nervous system that predominantly affects women of reproductive age. Pregnancy requires careful pharmacological decision-making because maternal relapse can lead to severe neurological disability, while fetal exposure to immunosuppressive therapy remains an important safety concern. We report two contrasting clinical scenarios in pregnant women with NMOSD. Case 1 involved a 30-year-old primigravida with AQP4-IgG-negative NMOSD and weak isolated MOG-IgA positivity of uncertain clinical significance. At 11 weeks of gestation, she developed a disabling relapse with severe bilateral lower-limb weakness, sensory disturbance, inability to walk independently, and urinary dysfunction. High-dose intravenous methylprednisolone led to partial recovery. After multidisciplinary counseling, she chose pregnancy termination at 18+3 weeks because of residual disability, concerns about fetal drug exposure, possible need for further immunosuppression, and anticipated rehabilitation burden. Case 2 involved a 35-year-old primigravida with AQP4-IgG-positive NMOSD who had been clinically stable for approximately 1 year before conception while receiving prednisolone 10 mg/day and azathioprine 50 mg/day. This regimen was continued during pregnancy with neurological, obstetric, and clinical pharmacology monitoring. She remained relapse-free and delivered a healthy female infant at 38 weeks. The infant weighed 3,100 g, had Apgar scores of 10, 10, and 10 at 1, 5, and 10 min, and showed normal growth and development at 12 months. These cases are not directly comparable and cannot establish treatment efficacy or pregnancy outcome causality. They highlight the need for preconception counseling, individualized risk-benefit assessment, careful use of pregnancy-compatible maintenance therapy when clinically indicated, and multidisciplinary follow-up. Isolated weak MOG-IgA positivity requires cautious interpretation.
2026-08-12 | Clinical Use of Interleukin-6 Blockade in Neuroimmunological Disorders.
Interleukin-6 (IL-6) is a multifunctional cytokine that plays a critical role in immune regulation, host defense, and tissue repair. Within the central nervous system (CNS), IL-6 contributes to both neuroprotection and neuroinflammation, depending on the signaling pathway involved; classic signaling, trans-signaling, or trans-presentation. Dysregulation of IL-6, particularly through sustained overexpression, disrupts the blood-brain barrier (BBB) integrity, promotes glial activation, and amplifies chronic inflammation, thereby contributing to the pathophysiology of numerous neurological disorders. This review aims to evaluate the role of IL-6 in neuroinflammatory processes and its clinical implications across a spectrum of neurological diseases. It focuses on the therapeutic potential and safety profile of IL-6 inhibitors, particularly tocilizumab and satralizumab. Key conditions discussed include neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein-associated disease (MOGAD), autoimmune encephalitis (AE), neuro-Behçet's disease (NBD), myasthenia gravis (MG), epilepsy, multiple sclerosis (MS), and Alzheimer's disease (AD). Clinical trials have demonstrated the efficacy of IL-6 receptor blockade in reducing relapse rates in NMOSD, leading to regulatory approvals. Promising off-label results have also been reported in treatment-resistant cases of MOGAD, epilepsy, and autoimmune conditions. However, IL-6 inhibition carries risks such as serious infections and paradoxical inflammatory reactions. Targeting the IL-6 pathway represents a significant advancement in neuroimmunology, offering new therapeutic opportunities for otherwise refractory conditions. Future research should focus on large-scale randomized controlled trials and the development of IL-6 inhibitors capable of crossing the BBB to enhance CNS-specific efficacy. Cost-related accessibility also remains a major challenge for broader clinical application.
2026-08-11 | Obinutuzumab β for aquaporin-4-positive neuromyelitis optica spectrum disorder: a phase 3 randomized controlled trial.
Although CD20-directed B cell depletion has long been used in neuromyelitis optica spectrum disorder (NMOSD), high-quality, large-scale, randomized controlled trials remain limited. In this multicenter, randomized, double-blind phase 3 trial, we evaluated obinutuzumab β (MIL62), a novel glycoengineered type II anti-CD20 monoclonal antibody, in patients with NMOSD. Eligible participants aged 18-70 years with aquaporin-4-immunoglobulin G (AQP4-IgG)-seropositive NMOSD and an Expanded Disability Status Scale (EDSS) score of 7.0 or lower were randomly assigned (1:1) to receive intravenous obinutuzumab β 1,000 mg (n = 45) or placebo (n = 46). The primary outcome-time to first adjudicated relapse on or before week 52-was met: relapse occurred in two of 45 (4.4%) obinutuzumab β-treated participants and in 21 of 46 (45.7%) placebo-treated participants (hazard ratio = 0.069, 95% confidence interval: 0.016-0.296, P < 0.0001). The incidence of grade 3 or higher treatment-related adverse events was similar between the obinutuzumab β group (6.7%) and the placebo group (6.5%). These findings support obinutuzumab β as a glycoengineered type II anti-CD20 therapeutic option for patients with AQP4-IgG+ NMOSD. ClinicalTrials.gov identifier: NCT05314010 .
2026-08-08 | Complement C3 inhibitory peptide AMY-101 ameliorates brain injury in a mouse model of NMOSD.
Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory demyelinating disease of the central nervous system, clinically characterized primarily by optic neuritis and transverse myelitis. This study aimed to investigate the therapeutic potential of the complement C3 inhibitory peptide AMY-101 in experimental models of NMOSD. In vitro experiments were performed using AQP4-transfected cells exposed to AQP4-IgG and human complement to assess complement-dependent cytotoxicity and membrane attack complex (MAC) deposition. In vivo efficacy was evaluated in an intracerebral injection mouse model of NMOSD, in which histopathological changes after AMY-101 treatment were compared with those in untreated controls. AMY-101 significantly attenuated AQP4-IgG- and complement-mediated cytotoxicity and inhibited MAC formation in vitro. In the NMOSD mouse model, AMY-101 treatment markedly reduced astrocyte loss, AQP4 depletion, and demyelination compared with controls. These findings demonstrate that complement C3 inhibition with AMY-101 effectively ameliorates key pathological features of NMOSD in experimental models, supporting its potential as a therapeutic strategy and providing a rationale for further preclinical and clinical investigation.
2026-08-05 | Association of therapeutic plasma exchange with functional outcomes in selected neurological disorders: a retrospective cohort study from a single tertiary center in Saudi Arabia.
Neurological disorders are associated with considerable morbidity and healthcare impact. Therapeutic plasma exchange (TPE) is an intervention that removes pathogenic antibodies, immune complexes, and other plasma constituents from circulation. Previous studies have suggested that TPE could be associated with improved outcomes in selected neurological disorders. To evaluate functional outcomes following therapeutic plasma exchange in patients with selected neurological disorders at National Guard Health Affairs (NGHA) in Jeddah, Saudi Arabia. This retrospective cohort study analyzes 133 patients diagnosed with various neurological disorders who received TPE between August 2015 and December 2022 at NGHA. Diagnoses included multiple sclerosis (MS), myasthenia gravis (MG), Guillain-Barré syndrome (GBS), neuromyelitis optica spectrum disorder (NMOSD), chronic inflammatory demyelinating polyneuropathy (CIDP), autoimmune encephalitis (AE), and other neurological conditions including amyotrophic lateral sclerosis (ALS), transverse myelitis, cerebellar ataxia, paraneoplastic neurologic syndrome, polymyositis, and central nervous system (CNS) infections. The effectiveness of TPE was assessed using the Modified Rankin Scale (mRS) before and 90 days following the final TPE session. Statistical analysis included Wilcoxon signed-rank tests and Mann-Whitney U test, with significance set at (p < 0.05). Significant improvements in mRS scores were observed following TPE for MS, MG, and GBS (all p < 0.001), as well as for NMOSD (p = 0.008), CIDP (p = 0.007), and AE (p = 0.018), but not in other neurological disorders (p = 0.234). Overall mortality was 6.8%, with no TPE-related deaths. Comorbidities among deceased patients included hypertension, diabetes mellitus, malignancy, chronic kidney disease, and cardiovascular disease. TPE was associated with improved functional outcomes in selected neurological disorders. Comorbidities were common among patients with poorer outcomes. Due to the retrospective design and potential confounding factors, causal inferences cannot be established. Further prospective studies are warranted to evaluate the role of TPE and optimize patient selection.
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Drug Discovery Landscape
10 orphan drug designations for Neuromyelitis optica spectrum disorder, including 6 approved therapies.
10 orphan drug designations for Neuromyelitis optica spectrum disorder, including 6 approved therapies.
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
Edralbrutinib | small molecules | FDA | 2023-04-24 | — | eVenus Pharmaceutical Lab Inc. |
Inebilizumab [Uplizna] | antibodies | EMA | 2017-03-20 | — | Viela Bio B.V. |
ublituximab | antibodies | FDA | 2016-08-25 | — | TG Therapeutics, Inc. |
Humanised anti-IL-6 receptor monoclonal antibody [Enspryng] | antibodies | EMA | 2016-06-27 | 2021-06-29 | Roche Registration GmbH |
inebilizumab [Uplizna] | antibodies | FDA | 2016-02-10 | 2020-06-11 | Horizon Therapeutics Ireland DAC |
cladribine | small molecules | FDA | 2015-03-19 | — | Chord Therapeutics S.a.r.l. |
satralizumab-mwge [Enspryng] | antibodies | FDA | 2014-06-30 | 2020-08-14 | Genentech, Inc. |
Eculizumab [Soliris] | antibodies | EMA | 2013-08-05 | 2019-08-28 | Alexion Europe SAS |
ravulizumab-cwvz [Ultomiris] | antibodies | FDA | 2013-06-24 | 2024-03-22 | Alexion Pharmaceuticals, Inc. |
eculizumab [Soliris] | antibodies | FDA | 2013-06-24 | 2019-06-27 | Alexion Pharmaceuticals, Inc. |
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