An open label study of the effects of rituximab in neuromyelitis optica

The Evolution of Anti-CD20 Treatment for Multiple Sclerosis: Optimization of Antibody Characteristics and Function

B-cell depletion with CD20-targeted agents is commonly used for treatment of multiple sclerosis (MS), other autoimmune diseases, and certain hematologic malignancies. Initial apparent success with rituximab in MS and neuromyelitis optica spurred development of the anti-CD20 monoclonal antibody (mAb) therapies ocrelizumab, ofatumumab, and ublituximab as well as the anti-CD19 mAb inebilizumab. While each are effective at targeting and depleting B cells, structural differences translate into different mechanisms of action affecting maintenance of B-cell depletion and safety and tolerability. Although the anti-CD20 mAbs differ in degree of human versus mouse sequences as well as target CD20 epitope, these properties do not appear to substantially affect activity or tolerability. In contrast, an antibody-dependent cell-mediated cytotoxicity (ADCC) versus a complement-dependent cytotoxicity mechanism of action as well as subcutaneous versus intravenous administration may provide improved tolerability. Glycoengineering of the mAbs ublituximab and inebilizumab enhances ADCC and can overcome the reduced responses to mAb-mediated B-cell depletion associated with certain genetic polymorphisms. Other strategies for therapeutic targeting of CD20, including brain shuttle antibodies (e.g., RO7121932), bispecific antibodies, chimeric antigen receptor T-cell therapies, and antibody-drug conjugates, are in active clinical development and may be future treatment approaches in MS and other B-cell-mediated autoimmune diseases.

Toward curing neurological autoimmune disorders: Biomarkers, immunological mechanisms, and therapeutic targets

Autoimmune neurology is a rapidly expanding field driven by the discovery of neuroglial autoantibodies and encompassing a myriad of conditions affecting every level of the nervous system. Traditionally, autoantibodies targeting intracellular antigens are considered markers of T cell-mediated cytotoxicity, while those targeting extracellular antigens are viewed as pathogenic drivers of disease. However, recent advances highlight complex interactions between these immune mechanisms, suggesting a continuum of immunopathogenesis. The breakdown of immune tolerance, central to these conditions, is affected by modifiable and non-modifiable risk factors such as genetic predisposition, infections, and malignancy. While significant therapeutic advancements have revolutionized treatment of certain diseases, such as neuromyelitis optica, our understanding of many others, particularly T cell-mediated conditions, remains limited, with fewer treatment options available. Future research should focus on improving effector function modeling and deepening our understanding of the factors influencing immune tolerance, with the goal of providing novel treatment options and improving patient care.

Disease-modifying treatments for neuromyelitis optica spectrum disorder in the context of a new generation of biotherapies

Neuromyelitis optica spectrum disorder (NMOSD) is a rare but debilitating autoimmune disease of the central nervous system (CNS) for which several biotherapies have recently been approved on the market. Historically, NMOSD disease-modifying treatments relied on wide-spectrum off-label immunosuppressants, such as azathioprine, mycophenolate mofetil, and cyclophosphamide. Since 2015, evidence has accumulated to support off-label biotherapies (rituximab and tocilizumab) and to approve satralizumab, inebilizumab, eculizumab, and ravulizumab. This next generation of drugs provides several targeted disease-modifying treatment options for NMOSD. Here, we review this modern panel. We first review the mechanistic rationales associated with their specific targets. We then review the pivotal evidence supporting their use in practice and their respective regimens. Lastly, we discuss the positioning of each therapeutic class. The current therapeutic options in NMOSD comprise three targeted mechanisms at different stages of a unique tissue-injury cascade: B-cell depleting, anti-cytokine, and anti-complement therapies. One drug has been approved on the market in each class. The current consensus proposes positioning the approved drugs as first-line treatments for newly-diagnosed patients and as alternative therapies in case of failure of historical treatment. Yet, there has been limited acceptance in practice due to high drug prices.

The correlation between rituximab dose reduction and acute relapses of neuromyelitis optica spectrum disorder, lessons from COVID-19 epidemic

BACKGROUND

COVID-19 was a viral infection that led to a global pandemic in March 2020. At the beginning of the pandemic, clinicians encountered the challenge of how immunosuppressive treatments would affect the course of COVID-19 infection in people with autoimmune diseases. Neuromyelitis optica spectrum disorder is an autoimmune astrocytopathy that is caused by an inflammation in the CNS. Major treatments to prevent acute relapses include immunosuppressive drugs. Rituximab is a well-established immunosuppressive agent in NMOSD maintenance therapy. Some reports suggested that treatment with Rituximab might increase the risk of COVID-19 infection and its mortality in NMOSD. On the other hand, dose reduction or extended interval treatment might lead to acute relapses of NMOSD and permanent disability.

METHODS

In this study, we evaluated the correlation between the dose of rituximab and the relapse rate of NMOSD during an epidemic. This was an observational study on 171 patients among whom 55 cases were seropositive. Some patients received full dose rituximab routinely (1000 mg/dose, every 6 months), but others were treated with half dose (500 mg/dose) during the epidemic. Also, some doses were prescribed with a delay, based on the level of CD19 and CD20.

RESULTS

The Pearson correlation coefficient (r) showed a negative and significant relation (r: - 0.19, p: 0.022) between the amount of drug and the number of relapses in the seropositive group, so low dosage of the drug was related to more acute relapses. In seronegative cases, there was not any valuable relationship. (p: 0.367).

CONCLUSION

Lower dose of rituximab, especially in seropositive NMOSD patients, can potentially lead to acute relapses. So, the more frequent evaluation of the CD19, CD20, and, CD27 levels, and the general clinical condition of the patients should be considered.

The monitoring of B lymphocytes in non-lymphoma patients following rituximab treatment

RTX was initially used for non-Hodgkin's lymphoma treatment and has been used in the clinical treatment of various autoimmune diseases as well as in antirejection and immune induction therapy for kidney transplant recipients. Following RTX treatment, the time for B cell regeneration varies among patients, but there is no unified recommendation for the frequency of B cell monitoring. This study aimed to investigate the clinical significance of periodic monitoring of peripheral blood B lymphocytes in individualized immunotherapy following rituximab (RTX) treatment in patients with different diseases. This study included 488 patients with different diseases divided in four groups who were hospitalized and followed up from April 2017 to March 2024 (including 77, 161, 120, and 130 cases of neuromyelitis optica, pemphigus, membranous nephropathy, and kidney transplant recipients, respectively). Dynamic changes in percentage and absolute count of peripheral blood B lymphocytes before and after RTX treatment were investigated in the four groups, as well as the number of B cell subsets in 32 patients with optic neuromyelitis after RTX treatment. Although most patients showed high expression of B cells after 24 weeks, less than 6.8% of patients still began to experience B cell regeneration within 4 weeks. Thus, regular B cell monitoring following RTX treatment is helpful to better track the remission and recurrence of the disease and provide effective laboratory support for the selection and implementation of individualized immunotherapy.

Hybrid immunity augments cross-variant protection against COVID-19 among immunocompromised individuals

BACKGROUND

Immunity to SARS-CoV-2 vaccination and infection differs considerably among individuals. We investigate the critical pathways that influence vaccine-induced cross-variant serological immunity among individuals at high-risk of COVID-19 complications.

METHODS

Neutralizing antibodies to the wild-type SARS-CoV-2 virus and its variants (Beta, Gamma, Delta and Omicron) were analyzed in patients with autoimmune diseases, chronic comorbidities (multimorbidity), and healthy controls. Antibody levels were assessed at baseline and at different intervals up to 12 months following primary and booster vaccination with either BNT162b2 or mRNA-1273. Immunity induced by vaccination with and without infection (hybrid immunity) was compared with that of unvaccinated individuals with recent SARS-CoV-2 infection. Plasma cytokines were analyzed to investigate variations in antibody production following vaccination.

RESULTS

Patients with autoimmune diseases (n = 137) produced lesser antibodies to the wild-type SARS-CoV-2 virus and its variants compared with those in the multimorbidity (n = 153) and healthy groups (n = 229); antibody levels were significantly lower in patients with neuromyelitis optica and those on prednisolone, mycophenolate or rituximab treatment. Multivariate logistic regression analysis identified neuromyelitis optica (odds ratio 8.20, 95% CI 1.68-39.9) and mycophenolate (13.69, 3.78-49.5) as significant predictors of a poorer antibody response to vaccination (i.e, neutralizing antibody <40%). Infected participants exhibited antibody levels that were 28.7% higher (95% CI 24.7-32.7) compared to non-infected participants six months after receiving a booster vaccination. Individuals infected during the Delta outbreak generated cross-protective neutralizing antibodies against the Omicron variant in quantities comparable to those observed after infection with the Omicron variant itself. In contrast, unvaccinated individuals recently infected with the wild-type (n = 2390) consistently displayed lower levels of neutralizing antibodies against both the wild-type virus and other variants. Pathway analyses suggested an inverse relationship between baseline T cell subsets and antibody production following vaccination.

CONCLUSION

Hybrid immunity confers a robust protection against COVID-19 among immunocompromised individuals.

The efficacy and safety of eculizumab in patients and the role of C5 polymorphisms

Eculizumab is an orphan drug with indications for extremely rare autoimmune disorders. It is primarily prescribed for use in patients with paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome; but is also highly effective in the treatment of myasthenia gravis, among others. By binding to the C5 protein in the complement system, eculizumab effectively inhibits cellular hemolysis and autoimmune reactions. Despite this effective treatment, some patients reported no improvement in symptoms. Genetic sequencing revealed three distinct C5 mutations in the non-responders and these polymorphisms appeared to be most prevalent among Japanese, Korean and African populations. Here, we present an overview of the current and potential future applications of eculizumab, as well as the disadvantages of eculizumab treatment in patients with C5 polymorphisms.

Rituximab Therapy for Immune-Mediated Neurological Diseases: Our Experience at a Tertiary Care Centre

INTRODUCTION

Rituximab (RTX) is a monoclonal anti-CD20 chimeric antibody that inhibits B cell activity. However, it is an appealing substitute for traditional immunomodulatory drugs as a swiftly acting, targeted therapy with mounting evidence of efficacy and tolerance in numerous neuroinflammatory conditions. We discuss the scientific evidence for the use of RTX in neurological illnesses, as well as the dose, safety, and other practical elements of prescription.

AIM

This study aims to assess and correlate the effects of RTX on immune-mediated neurological disorders.

OBJECTIVES

The primary objective of this study is to determine the outcomes in patients treated with RTX for the following conditions: myasthenia gravis (MG), autoimmune encephalitis, multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein antibody disease (MOGAD), immune-mediated peripheral neuropathy, and inflammatory muscle disease. The secondary objective is to assess adverse drug reactions in patients treated with RTX.

METHODS

This is a prospective observational study conducted at a tertiary care centre. The data were analyzed for the period from May 2022 to May 2024. Approval was obtained from the institutional ethics committee before commencing the study, and written informed consent was obtained from all patients.

RESULTS AND CONCLUSIONS

A total of 56 patients were included in the study. The distribution of patients according to diseases is as follows: MG (17), MS (11), NMOSD (10), MOGAD (7), immune-mediated peripheral neuropathy (6), autoimmune encephalitis (3), and inflammatory muscle disease (2). However, one patient was lost to follow-up in the autoimmune encephalitis group. All patients experienced improvements in symptoms, and no relapse episodes have been reported except for one patient who had a relapse in the inflammatory muscle disease group. During the infusion process, some adverse drug reactions, such as chills and rigors, were observed, and two patients experienced major side effects, such as Pott's disease and cryptogenic organizing pneumonia. Nevertheless, overall, rituximab shows promise as an off-label immunosuppressive treatment for the aforementioned neurological immune-mediated diseases.

Long-term efficacy and safety of rituximab in the treatment of neuromyelitis Optica Spectrum disorder

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing, autoimmune, inflammatory astrocytopathy. Rituximab for B-cell suppression is a common treatment for NMOSD; however, large-scale randomised controlled trials are lacking.

Objective

Evaluate long-term efficacy and safety of rituximab for NMOSD.

Methods

Retrospective observational study of patients with NMOSD treated with rituximab. Annualised relapse rates (ARRs) before and during rituximab treatment were evaluated; Modified Rankin Scores (mRS) were measured as a marker of disability.

Results

In total, 37 patients were included: 27 aquaporin-4-IgG-seropositive and 10 seronegative NMOSD. The predominant rituximab dosing regimen was an initial 1000 mg, split over two 500 mg infusions, two weeks apart, followed by single 500 mg doses. Over a median follow-up of 54 months, ARR for the whole cohort was 0.136 (95% CI 0.088-0.201), significantly lower than the pretreatment ARR of 0.366 (95% CI 0.271-0.483, p < 0.001). There was a significant reduction in ARR for the seropositive subgroup, but not seronegative. Significant improvement in mRS was seen post-treatment. Infections were reported in 32% of patients during follow-up; most were mild.

Conclusion

Rituximab, at doses lower than traditionally used, may be an efficacious therapy for NMOSD, with a favourable safety profile.

Efficacy and safety of rituximab in multiple sclerosis and neuromyelitis optica spectrum disorder

In Thailand, resource limitations lead many multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) patients to use off-label immunosuppressants. This study assesses the efficacy and safety of rituximab (RTX) with a CD19-based reinfusion regimen among Thai MS and NMOSD patients. A retrospective review of patients at the Faculty of Medicine Siriraj Hospital from January 1994 to April 2023 was conducted. The primary outcome assessed was the change in annualized relapse rate (ARR) for patients using RTX for over a year. Secondary outcomes included changes in the Expanded Disability Status Scale (EDSS) scores, time to the first relapse after RTX initiation for patients using RTX for over a year, and an evaluation of the safety of RTX. The study encompassed 36 MS and 39 NMOSD patients. A majority of patients (91.7% of MS and 79.5% of NMOSD) experienced no relapses during a median follow-up of 30 months (Interquartile range [IQR] 20-46) and 31 months (IQR 23-41), respectively. The median ARR significantly decreased in both MS (from 0.77 [IQR 0.42-1.83] to 0 [IQR 0-0], p < 0.001) and NMOSD (from 0.92 [IQR 0.68-1.78] to 0 [IQR 0-0.17], p < 0.001) patients after switching to RTX, with no difference between those following a fixed 6-month time point regimen and a CD19-based reinfusion regimen. Median EDSS scores improved significantly at the last follow-up visit in both groups. The mean time to the first subsequent relapse was 8.3 ± 3.0 months in MS and 6.8 ± 1.7 months in NMOSD. Mild adverse drug reactions occurred in 44% of patients. RTX effectively prevents relapses in Thai MS and NMOSD patients, with no observed serious adverse drug reactions.

Intruders or protectors - the multifaceted role of B cells in CNS disorders

B lymphocytes are immune cells studied predominantly in the context of peripheral humoral immune responses against pathogens. Evidence has been accumulating in recent years on the diversity of immunomodulatory functions that B cells undertake, with particular relevance for pathologies of the central nervous system (CNS). This review summarizes current knowledge on B cell populations, localization, infiltration mechanisms, and function in the CNS and associated tissues. Acute and chronic neurodegenerative pathologies are examined in order to explore the complex, and sometimes conflicting, effects that B cells can have in each context, with implications for disease progression and treatment outcomes. Additional factors such as aging modulate the proportions and function of B cell subpopulations over time and are also discussed in the context of neuroinflammatory response and disease susceptibility. A better understanding of the multifactorial role of B cell populations in the CNS may ultimately lead to innovative therapeutic strategies for a variety of neurological conditions.

Evidence-based management of optic neuritis

PURPOSE OF REVIEW

Optic neuritis can result from several distinct causes, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody disease (MOGAD), when not idiopathic. This review discusses evidence-based treatment approaches contingent upon each specific cause of optic neuritis.

RECENT FINDINGS

Current evidence highlights the need for prompt plasmapheresis as adjunct to intravenous methylprednisolone (IVMP) in patients with NMOSD-associated optic neuritis. Recent advances have included a proliferation of novel disease modifying therapies (DMTs) for long-term management of NMOSD and an understanding of how existing therapeutic options can be leveraged to optimally treat MOGAD.

SUMMARY

In acute idiopathic or MS-associated optic neuritis, IVMP hastens visual recovery, though it does not substantially affect final visual outcomes. IVMP and adjunctive plasmapheresis are beneficial in the treatment of NMOSD-associated optic neuritis, with a shorter time-to-treatment associated with a higher likelihood of recovery. The natural history of untreated MOGAD-associated optic neuritis is unclear but treatment with IVMP is near-universal given phenotypic similarities with NMOSD. Long-term immunosuppressive therapy is warranted in patients with NMOSD as well as in patients with MOGAD with poor visual recovery or recurrent attacks.

Monoclonal antibody therapies for aquaporin-4-immunoglobulin G-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease

Monoclonal antibody therapies mark the new era of targeted treatment for relapse prevention in aquaporin-4 (AQP4)-immunoglobulin G (IgG)-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD). For over a decade, rituximab, an anti-CD20 B-cell-depleting agent, had been the most effectiveness treatment for AQP4-IgG+NMOSD. Tocilizumab, an anti-interleukin-6 receptor, was also observed to be effective. In 2019, several randomized, placebo-controlled trials were completed that demonstrated the remarkable efficacy of eculizumab (anti-C5 complement inhibitor), inebilizumab (anti-CD19 B-cell-depleting agent), and satralizumab (anti-interleukin-6 receptor), leading to the Food and Drug Administration (FDA) approval of specific treatments for AQP4-IgG+NMOSD for the first time. Most recently, ravulizumab (anti-C5 complement inhibitor) was also shown to be highly efficacious in an open-label, external-controlled trial. Although only some patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) warrant immunotherapy, there is currently no FDA-approved treatment for relapse prevention in MOGAD. Observational studies showed that tocilizumab was associated with a decrease in relapses, whereas rituximab seemed to have less robust effectiveness in MOGAD compared to AQP4-IgG+NMOSD. Herein, we review the evidence on the efficacy and safety of each monoclonal antibody therapy used in AQP4-IgG+NMOSD and MOGAD, including special considerations in children and women of childbearing potential.

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.

Long-term Effects of IL-6 Receptor Blockade Therapy on Regulatory Lymphocytes and Neutrophils in Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND OBJECTIVES

Neuromyelitis optica spectrum disorder (NMOSD) is a disabling autoimmune neurologic disease. Anti-IL-6 receptor (IL-6R) therapy prevents relapses in patients with anti-aquaporin 4 (AQP4)-IgG-positive NMOSD; however, it remains unclear how cellular immune components are altered by anti-IL-6R therapy. In this study, we examined the long-term effects of the anti-IL-6R monoclonal antibody tocilizumab (TCZ) on immune cell profiles in patients with NMOSD.

METHODS

Monthly IV injections of TCZ (8 mg/kg) were administered as an add-on therapy to 19 anti-AQP4-IgG-positive patients, who had been refractory to corticosteroids and immunosuppressive drugs. Peripheral blood was collected before infusion of TCZ for flow cytometry analysis of lymphocyte subsets. Seven patients provided whole blood samples for gene expression profiles.

RESULTS

Patients with NMOSD had reduced numbers of lymphocyte subsets with regulatory functions, including transitional B cells, CD56high NK cells, and CD45RA-FoxP3high regulatory T cells. However, after initiating TCZ therapy, the numbers increased to normal levels within 1 year. Gene expression analysis revealed that neutrophil granule-related genes, predominated by those related to azurophil granules, were significantly upregulated in patients with NMOSD. Such alterations suggestive of accelerated myeloid turnover were not observed 1 year after TCZ therapy, and the effects of TCZ on some neutrophil genes were observed as early as 5 days after starting TCZ. In vitro analysis demonstrated that naïve T-cell division was impaired in the enrolled patients, which was fully recovered after 18 months of therapy.

DISCUSSION

In patients with active NMOSD not treated with molecular targeting drugs, we observed reduction or deficiency in lymphocytes with regulatory potentials and activation of neutrophils. However, introduction of anti-IL-6R therapy accompanied by tapering concomitant drugs corrected such abnormalities, which might contribute to persistent relapse prevention. The recovery in the naïve T-cell division after starting TCZ may underlie the relatively low risk of infection in patients under anti-IL-6R therapy.

TRIAL REGISTRATION INFORMATION

University Hospital Medical Information Network Clinical Trials Registry: UMIN000005889 (July 8, 2011) and UMIN000007866 (May 1, 2012) (umin.ac.jp/ctr/index.htm). The first participant was enrolled on November 2, 2011.

Satralizumab as an add-on treatment in refractory pediatric AQP4-antibody-positive neuromyelitis optica spectrum disorder: a case report

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the central nervous system. Relapse and incomplete recovery from relapse are common in NMOSD. Most patients with NMOSD have IgG to aquaporin-4 (AQP4-IgG). New biological agents for AQP4-IgG-seropositive NMOSD, such as satralizumab, have become available for maintenance therapy. Satralizumab is an anti-interleukin-6 receptor monoclonal antibody. To date, few studies have evaluated satralizumab as an add-on treatment in pediatric NMOSD patients. Here, we report an 11-year-old girl with NMOSD who frequently relapsed under long-term treatment, including oral prednisone, rituximab, mycophenolate mofetil (MMF), and maintenance intravenous immunoglobulin treatment even with B-cell depletion. For the poor treatment response and to improve the efficacy of relapse prevention further, the patient received satralizumab treatment as an add-on therapy to MMF plus oral prednisone, with a dose of 120 mg administered subcutaneously at weeks 0, 2, and 4 and every 4 weeks after that. After initiating satralizumab, the patient remained relapse-free for 14 months at the last follow-up. Satralizumab might be effective and safe as an add-on treatment in refractory pediatric AQP4-IgG-seropositive NMOSD under B-cell depletion.

Early rituximab treatment reduces long-term disability in aquaporin-4 antibody-positive neuromyelitis optica spectrum

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) causes relapsing inflammatory attacks in the central nervous system, leading to disability. As rituximab, a B-lymphocyte-depleting monoclonal antibody, is an effective in preventing NMOSD relapses, we hypothesised that earlier initiation of rituximab can also reduce long-term disability of patients with NMOSD.

METHODS

This multicentre retrospective study involving 19 South Korean referral centres included patients with NMOSD with aquaporin-4 antibodies receiving rituximab treatment. Factors associated with the long-term Expanded Disability Status Scale (EDSS) were assessed using multivariable regression analysis.

RESULTS

In total, 145 patients with rituximab treatment (mean age of onset, 39.5 years; 88.3% female; 98.6% on immunosuppressants/oral steroids before rituximab treatment; mean disease duration of 121 months) were included. Multivariable analysis revealed that the EDSS at the last follow-up was associated with time to rituximab initiation (interval from first symptom onset to initiation of rituximab treatment). EDSS at the last follow-up was also associated with maximum EDSS before rituximab treatment. In subgroup analysis, the time to initiation of rituximab was associated with EDSS at last follow-up in patients aged less than 50 years, female and those with a maximum EDSS score ≥6 before rituximab treatment.

CONCLUSIONS

Earlier initiation of rituximab treatment may prevent long-term disability worsening in patients with NMOSD, especially among those with early to middle-age onset, female sex and severe attacks.

Rituximab at lower dose for neuromyelitis optica spectrum disorder: a multicenter, open-label, self-controlled, prospective follow-up study

Objective

To address a novel lower-dose rituximab (RTX) therapy strategy based on our clinical experience and assess its efficacy and safety in neuromyelitis optica spectrum disorder (NMOSD).

Methods

A multicenter, open-label, self-controlled, prospective follow-up study. Totally, 108 NMOSD patients were enrolled and a lower-dose RTX strategy was applied including 100 mg weekly for 3 weeks and then reinfusions every 6 months. Annualized relapse rate (ARR), the expanded disability status scale (EDSS) score and length of spinal cord lesions were included to evaluate the efficacy. Side effects were recorded to assess the safety profile.

Results

Of 108 patients, 80 (74.1%) initiated low-dose RTX therapy immediately after acute attack treatment and 33 (30.6%) initiated it after the first attack. During a median treatment period of 35.5 (22.0-48.8) months, significant decreases were observed in median ARR (1.1 [0.8-2.0] versus 0 [0-0.2], p < 0.001), EDSS score (3.5 [2.5-4.0] versus 2.0 [1.0-3.0], p < 0.001) and spinal cord lesion segments (5.0 [4.0-8.0] versus 3.0 [1.0-6.0], p < 0.001). The cumulative risk of relapses significantly decreased during the post- versus pre-RTX period (HR 0.238, 95%CI 0.160-0.356, p < 0.001) and on early therapy initiated within 24 months after disease onset versus delayed therapy (HR 0.506, 95%CI 0.258-0.994, p = 0.041). No serious side effects were recorded and all the subjects did not discontinue treatment due to RTX-related side effects.

Conclusion

Our research provided evidence supporting the lower-dose RTX strategy in treating NMOSD and reopened the issues of optimal dosage and therapy initiation timing.

Research progress on pathogenesis and clinical treatment of neuromyelitis optica spectrum disorders (NMOSDs)

Neuromyelitis optica spectrum disorders (NMOSDs) are characteristically referred to as various central nervous system (CNS)-based inflammatory and astrocytopathic disorders, often manifested by the axonal damage and immune-mediated demyelination targeting optic nerves and the spinal cord. This review article presents a detailed view of the etiology, pathogenesis, and prescribed treatment options for NMOSD therapy. Initially, we present the epidemiology of NMOSDs, highlighting the geographical and ethnical differences in the incidence and prevalence rates of NMOSDs. Further, the etiology and pathogenesis of NMOSDs are emphasized, providing discussions relevant to various genetic, environmental, and immune-related factors. Finally, the applied treatment strategies for curing NMOSD are discussed, exploring the perspectives for developing emergent innovative treatment strategies.

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.

Therapeutic response to rituximab in seropositive neuromyelitis optica: Experience from a tertiary care center in South India

Objectives

Neuromyelitis optica (NMO) is a severe central nervous system demyelinating disease caused by autoantibodies to anti-aquaporin-4 immunoglobulin-G (AQP4-IgG). Rituximab, a monoclonal antibody targeting CD20 cells, is effective in neuromyelitis optica spectrum disorder (NMOSD) in several observational studies and small randomized controlled trials. However, this includes both AQP4-IgG antibody positive and negative cases. Whether rituximab is more effective in seropositive NMO is unknown. The aim of the study was to determine the efficacy of rituximab in seropositive NMO.

Materials and Methods

This single-center ambispective study with retrospective data collection and prospective follow-up included patients with NMOSD who were positive for AQP4-Ig-G and treated with rituximab. Efficacy outcomes assessed were annualized relapse rate (ARR), disability progression by expanded disability status scale (EDSS), very good outcome (defined as no relapse and an EDSS ≤3.5), and persistent antibody positivity. Safety was also monitored.

Results

Between June 2017 and December 2019, 15 AQP4-IgG-positive cases were identified. The mean (± SD) age was 36 ± 17.9 years and 73.3% were females. Transverse myelitis followed by optic neuritis was the most common presentations. Rituximab was initiated after a median period of 19-weeks from the disease onset. The mean number of rituximab doses received was 6.4 ± 2.3. After a mean follow-up duration of 107 ± 74.7 weeks from the first dose of rituximab, ARR significantly reduced from 0.5 ± 0.9 to 0.02 ± 0.08, difference 0.48 ± 0.86 (95% confidence intervals [CI], 0.0009-0.96; P = 0.05). The number of relapses also reduced significantly from 0.6 ± 0.8-0.07 ± 0.26 , a difference of 0.53 ± 0.91 (95% CI, 0.026-1.05; P = 0.041). EDSS also significantly reduced from 5.6 ± 2.5-3.3 ± 2.9 , a difference of 2.23 ± 2.36 (95% CI, 0.93-3.54; P = 0.003). Very good outcome was obtained in 73.3% (11 of 15); P = 0.002. AQP4-IgG remained positive in 66.7% (4 of 6) when repeated after a mean period of 149.5 ± 51.1 weeks after the first dose of rituximab. Neither pre-treatment ARR, EDSS, time to initiate rituximab, the total number of rituximab doses, or time to repeat AQP4-IgG were significantly associated with persistent antibody positivity. No serious adverse events were observed.

Conclusion

Rituximab exhibited high efficacy and good safety in seropositive NMO. Larger trials in this subgroup are warranted to confirm these findings.

Clinical and epidemiological correlates of treatment change in patients with NMOSD: insights from the CIRCLES cohort

OBJECTIVE

Neuromyelitis optica spectrum disorders (NMOSD) represent rare autoimmune diseases of the central nervous system largely targeting optic nerve(s) and spinal cord. The present analysis used real-world data to identify clinical and epidemiological correlates of treatment change in patients with NMOSD.

METHODS

CIRCLES is a longitudinal, observational study of NMOSD conducted at 15 centers across North America. Patients with ≥ 60 days of follow-up and receiving on-study maintenance treatment were evaluated. The mean annual relapse rate (ARR) was estimated using negative binomial models; the likelihood of treatment change was estimated using Cox proportional hazards models. Relapses were included as time-varying covariates to estimate the relationship to treatment change.

RESULTS

Of 542 patients included, 171 (31.5%) experienced ≥ 1 relapse on the study and 133 patients (24.5%) had ≥ 1 change in the treatment regimen. Two categories of variables significantly correlated with the likelihood of treatment change: (1) relapse: any on-study relapse (hazard ratio [HR] = 2.91; p < 0.001), relapse phenotypes (HR range = 2.15-5.49; p < 0.001), and pre-study ARR > 0.75 (HR 2.28; p < 0.001); 2) disease phenotype: brain syndrome only vs transverse myelitis involvement at onset (HR 2.44; p = 0.008), disease duration < 1 vs > 5 years (HR 1.66; p = 0.028), or autoimmune comorbidity (HR 1.55; p = 0.015). A subset of these factors significantly correlated with shorter time to first rituximab discontinuation.

CONCLUSIONS

In CIRCLES, relapse patterns and disease phenotype significantly correlated with changes in the maintenance treatment regimen. Such findings may facilitate the identification of patients with NMOSD who are likely to benefit from treatment change to reduce relapse risk or disease burden and enhance the quality of life.

B cell targeted therapies in inflammatory autoimmune disease of the central nervous system

Cumulative evidence along several lines indicates that B cells play an important role in the pathological course of multiple sclerosis (MS), neuromyelitisoptica spectrum disorders (NMOSD) and related CNS diseases. This has prompted extensive research in exploring the utility of targeting B cells to contain disease activity in these disorders. In this review, we first recapitulate the development of B cells from their origin in the bone marrow to their migration to the periphery, including the expression of therapy-relevant surface immunoglobulin isotypes. Not only the ability of B cells to produce cytokines and immunoglobulins seems to be essential in driving neuroinflammation, but also their regulatory functions strongly impact pathobiology. We then critically assess studies of B cell depleting therapies, including CD20 and CD19 targeting monoclonal antibodies, as well as the new class of B cell modulating substances, Bruton´s tyrosinekinase (BTK) inhibitors, in MS, NMOSD and MOGAD.

B-cell proliferation characteristics and monitoring significance under the modified reduced-dose rituximab regimen for NMOSD: A real-world case series study

OBJECTIVE

To explore the B-cell proliferation characteristics and monitoring significance under the modified reduced-dose rituximab (mRTX) regimen for neuromyelitis optica spectrum disorder (NMOSD).

METHODS

NMOSD patients treated with mRTX were recruited, and the percentages of total CD19⁺ B cells and CD27⁺ memory B cells were dynamically detected by flow cytometry. The annualized relapse rate (ARR) and expanded disability status scale (EDSS) scores were compared before and after mRTX treatment, and the differences in B-cell values were compared between groups.

RESULTS

A total of 34 patients with NMOSD were ultimately enrolled. The EDSS score decreased from 2.5 (1.5, 3.0) to 1.3 (1.0, 2.0), and the ARR decreased from 1.0 (0, 2.0) to 0 (0, 0) (p < 0.001). Relapses occurred in 6 patients, with total CD19⁺ B-cell percentages of 3.25% (2.7%, 3.7%) and CD27⁺ memory B-cell percentages of 0.3% (0.2%, 0.3%) at initial relapse. Twenty-eight patients (82.4%) remained relapse-free with 84 doses of mRTX. Before 56 repeated doses, the total CD19⁺ B cells and CD27⁺ memory B cells were 4.00% (3.14%, 5.32%) and 0.26% (0.17%, 0.40%), respectively. The mean dosing interval was 9.2 months. Both total CD19⁺ B cells and CD27⁺ memory B cells proliferated over time after mRTX use, with significantly faster proliferation rates in the later stages. In 28 relapse-free patients, the mean time to reach 1% for total CD19⁺ B cells was 210 days, and the mean time to reach 3% was 240 days, with the mean interval from 1% to 3% of 65 days. Twenty-five relapse-free patients had no significant differences in maximum, minimum, and mean B-cell values compared to those of 6 patients with relapse.

CONCLUSION

The high rate of B-cell proliferation under the mRTX regimen indicates that closer dynamic B-cell monitoring is required to guide repeated mRTX dosing. Sustained depletion of total CD19⁺ B cells targeting < 3% of lymphocytes may be feasible, enabling extended dosing intervals.

Efficacy of monoclonal antibodies in neuromyelitis optica: An updated systematic review with meta‐analysis

Objective

This is a critical review of studies aiming to assess the safety and efficacy of monoclonal antibodies as compared with the classical regimen in patients with neuromyelitis optica spectrum disorder.

Methods

Various electronic databases were searched for original articles reporting results from the use of monoclonal antibodies in neuromyelitis optica spectrum disorder. The Expanded Disability Status Scale and annualized relapse rate score before and after treatment were the primary effect measures. The pooled standardized mean difference with 95% CI was calculated using the random effects model. The heterogeneity of the included studies was calculated using Cochran's Q test and I2 statistics.

Results

Of 36 included studies, meta‐analysis was carried out from 27 studies. The pooled analysis of 1010 patients showed a mean reduction in the mean annualized relapse rate ratio after tocilizumab therapy −2.45 (95% CI −3.13 to −1.77) to be higher compared with rituximab −1.49 (95% CI −1.81 to −1.17). Likewise, the mean reduction in the Expanded Disability Status Scale after tocilizumab was higher −1.10 (95% CI −1.75 to −0.44) compared with rituximab −0.80 (95% CI −1.11 to −0.48).

Conclusion

Tocilizumab has a greater effect than rituximab in terms of the reduction of the annualized relapse rate and Expanded Disability Status Scale in neuromyelitis optica spectrum disorder patients. The greater efficacy of tocilizumab could result from its multiple dynamic pharmacodynamics (i.e. its effect on interleukin‐6‐dependent inflammatory processes, involving CD20‐negative plasmablasts, pathogenic T cells and regulatory T cells) and to some degree due to heterogeneity in our study. Satralizumab (monotherapy or add‐on), eculizumab and inebilizumab (monotherapy) are effective in aquaporin‐4‐positive cases with good safety profiles. Ublituximab, bortezomib, bevacizumab and C1‐esterase inhibitors are both effective and safe add‐on drugs.

Efficacy and safety of monoclonal antibodies in neuromyelitis optica spectrum disorders: A survival meta-analysis of randomized controlled trials

Background

Monoclonal antibodies such as rituximab (RTX), eculizumab, inebilizumab, satralizumab, and tocilizumab have been found to be effective therapies for neuromyelitis optica spectrum disease ​(NMOSD) in several clinical randomized controlled trials.

Objective

The purpose of this meta-analysis of randomized controlled trials was to assess the efficacy and safety of monoclonal antibodies in the treatment of NMOSD.

Methods

We searched the following databases for relevant English language literature from the establishment of the database to June 2021: PubMed, Embase, Cohorane Library, the Central Register of Controlled Trials (CENTRAL), and Web of Science. Randomized controlled trials of monoclonal antibodies were the targets of the review.

Results

We included seven trials containing 775 patients (485 in the monoclonal antibody group and 290 in the control group). Patients in the monoclonal group (HR 0.24, 95% CI: 0.14 to 0.40, P ​< ​0.00001), as well as patients with seropositive AQP4-IgG (HR 0.18, 95% CI: 0.11 to 0.29, P ​< ​0.00001), both had a higher free recurrence rate than that in the control group. In the first year (HR 0.25, 95% CI: 0.09 to 0.71, P ​= ​0.009) and the second year (HR 0.32, 95% CI: 0.13 to 0.81, P ​= ​0.02), no relapses were documented. The average changes of the expanded disability status scale (EDSS) score decreased by 0.29 (95% CI: -0.09 to 0.51, P ​= ​0.005). Upper respiratory tract infection (OR 1.52, 95% CI: 0.76 to 3.04, P ​= ​0.24), urinary tract infection(OR 0.79, 95% CI: 0.51 to 1.21, P ​= ​0.27), and headache (OR 1.30, 95% CI: 0.78 to 2.17, P ​= ​0.31) were three most frequent adverse reactions.

Conclusions

Monoclonal antibodies are particularly effective treatments in avoiding recurrence for NMOSD patients, according to this meta-analysis. The associated adverse responses are not significantly different from those seen with traditional immunosuppressants.

Comparison of Long-Term Use of Low Dose Rituximab and Mycophenolate Mofetil in Chinese Patients With Neuromyelitis Optica Spectrum Disorder

Background

Several studies have reported the efficacy and safety of rituximab (RTX) and mycophenolate mofetil (MMF) in neuromyelitis optica spectrum disorder (NMOSD). This study aimed to evaluate the efficacy and safety of long-term use of low-dose RTX and MMF in Chinese patients with NMOSD.

Methods

We retrospectively reviewed data from patients with NMOSD in our hospital. The enrolled patients were administrated different immunosuppressive agents. We accessed annual relapse rate (ARR), neurological disability (Expanded Disability Status Scale, EDSS), time to the next relapse, and adverse events.

Results

EDSS and ARR were both reduced after RTX and MMF treatment. Kaplan-Meier analysis indicated that patients treated with RTX had a longer time to next relapse compared other immunosuppressive agents before RTX (log-rank test: p &lt; 0.001). Furthermore, we evaluated the change of EDSS and ARR in RTX and MMF, and patients treated with RTX showed a better reduction. Eleven relapses from seven patients in group RTX and 20 relapses from 14 patients in group MMF were reported during follow-up.

Conclusion

Long-term using of low dose of RTX and MMF were effective and tolerable in Chinese patients with NMOSD. Compared with MMF, RTX showed a better way to reduce the ARR.

Monoclonal Antibody Therapies Beyond Complement for NMOSD and MOGAD

Aquaporin-4 (AQP4)-IgG seropositive neuromyelitis optica spectrum disorders (AQP4-IgG seropositive NMOSD) and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease (MOGAD) are inflammatory demyelinating disorders distinct from each other and from multiple sclerosis (MS).While anti-CD20 treatments can be used to treat MS and AQP4-IgG seropositive NMOSD, some MS medications are ineffective or could exacerbate AQP4-IgG seropositive NMOSD including beta-interferons, natalizumab, and fingolimod. AQP4-IgG seropositive NMOSD has a relapsing course in most cases, and preventative maintenance treatments should be started after the initial attack. Rituximab, eculizumab, inebilizumab, and satralizumab all have class 1 evidence for use in AQP4-IgG seropositive NMOSD, and the latter three have been approved by the US Food and Drug Administration (FDA). MOGAD is much more likely to be monophasic than AQP4-IgG seropositive NMOSD, and preventative therapy is usually reserved for those who have had a disease relapse. There is a lack of any class 1 evidence for MOGAD preventative treatment. Observational benefit has been suggested from oral immunosuppressants, intravenous immunoglobulin (IVIg), rituximab, and tocilizumab. Randomized placebo-controlled trials are urgently needed in this area.

Evolution of Anti-B Cell Therapeutics in Autoimmune Neurological Diseases

B cells have an ever-increasing role in the etiopathology of a number of autoimmune neurological disorders, acting as antigen-presenting cells facilitating antibody production but also as sensors, coordinators, and regulators of the immune response. In particular, B cells can regulate the T cell activation process through their participation in antigen presentation, production of proinflammatory cytokines (bystander activation or suppression), and contribution to ectopic lymphoid aggregates. Such an important interplay between B and T cells makes therapeutic depletion of B cells an attractive treatment strategy. The last decade, anti-B cell therapies using monoclonal antibodies against B cell surface molecules have evolved into a rational approach for successfully treating autoimmune neurological disorders, even when T cells seem to be the main effector cells. The paper summarizes basic aspects of B cell biology, discusses the roles of B cells in neurological autoimmunities, and highlights how the currently available or under development anti-B cell therapeutics exert their action in the wide spectrum and immunologically diverse neurological disorders. The efficacy of the various anti-B cell therapies and practical issues on induction and maintenance therapy is specifically detailed for the treatment of patients with multiple sclerosis, neuromyelitis-spectrum disorders, autoimmune encephalitis and hyperexcitability CNS disorders, autoimmune neuropathies, myasthenia gravis, and inflammatory myopathies. The success of anti-B cell therapies in inducing long-term remission in IgG4 neuroautoimmunities is also highlighted pointing out potential biomarkers for follow-up infusions.

Response to treatment in NMOSD: the Australasian experience

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is associated with significant morbidity and mortality. Several therapies have been recommended for NMOSD and more recently clinical trials have demonstrated efficacy for three monoclonal antibody therapies. We present a retrospective observational study of treatment response in NMOSD.

METHODS

This was a retrospective, unblinded, observational study of treatment efficacy for rituximab and traditional immunosuppressive therapy in patients with AQP4 antibody positive NMOSD. Treatment efficacy was assessed using annualised relapse rates (ARR), time to first relapse and expanded disability status scale (EDSS) scores.

RESULTS

Complete relapse and treatment data were available for 43/68 (63%) of AQP4 antibody positive NMOSD cases covering 74 episodes of treatment. In a time to first relapse analysis rituximab showed a risk ratio of 0.23 (95% CI 0.08 - 0.65) when compared with no treatment and there was a non-significant reduction in ARR of 35% compared to pre-treatment. β-interferon (p = 0.0002) and cyclophosphamide (p = 0.0034) were associated with an increased ARR compared to pre-treatment. Rituximab (median 4.0 [range 0.0 - 7.0]; p = 0.042) and traditional immunosuppressive therapy (median 4.0 [range 0.0 - 8.0]; p = 0.016) were associated with a lower final EDSS compared to β-interferon (median 6.0 [range 4.0 - 7.5]).

CONCLUSIONS

These data provide additional support for the use of rituximab in preference to traditional immunosuppressive agents and MS disease modifying therapies as first line treatment of NMOSD.

Inebilizumab for treatment of neuromyelitis optica spectrum disorder in patients with prior rituximab use from the N-MOmentum Study

BACKGROUND

The B-cell-depleting agent rituximab (anti-CD20) was historically used to prevent attacks in neuromyelitis optica spectrum disorder (NMOSD). Inebilizumab, which targets and depletes CD19-expressing B cells, plasmablasts, and some plasma cells, received approval from the US Food and Drug Administration for treatment of NMOSD based on results from the randomized, placebo-controlled, phase 2/3 N-MOmentum trial. Because of their closely related mechanisms of action, consideration as to whether inebilizumab may be a suitable treatment option for patients with prior rituximab experience is important. This post hoc analysis of data from N-MOmentum assessed inebilizumab efficacy and tolerability in participants previously treated with rituximab.

METHODS

Adjudicated attacks, secondary efficacy outcomes, and treatment-emergent adverse events were assessed by prior rituximab use during a 6-month randomized control period and open-label period.

RESULTS

Seventeen participants in N-MOmentum had prior rituximab use, of whom 13 were randomly assigned to the inebilizumab treatment group. Seven of these participants had breakthrough attacks prior to enrollment (annualized attack rate, 0.78 attacks/person-year) despite rituximab use. While they were receiving inebilizumab in the randomized control period, 1 of 13 participants with prior rituximab use had an attack (hazard ratio vs all placebo, 0.16; 95% confidence interval: 0.02 1.20; p = 0.07). Two additional participants with prior rituximab use experienced attacks on inebilizumab during the open-label period, with an overall annualized attack rate of 0.08 (95% confidence interval: 0.02 0.34) attacks/person-year. This annualized attack rate was similar to that of participants without prior rituximab use (0.10 [95% confidence interval: 0.07 0.15]). None of the 7 participants who experienced attacks while taking rituximab experienced an attack while receiving inebilizumab. Two (12%) participants with prior rituximab use experienced serious treatment-emergent adverse events related to inebilizumab, with serious or grade ≥3 infections occurring in 3 (18%) participants each. No deaths or opportunistic infections were reported in this cohort.

CONCLUSIONS

These findings support the efficacy of inebilizumab in participants with NMOSD who had previously been treated with rituximab. Infections occurred in nearly all study participants with prior rituximab exposure, highlighting a need for clinical vigilance in such individuals. Further studies are necessary to determine potential safety concerns of inebilizumab, including risk of infection, in rituximab-experienced patients. ClinicalTrials.gov identifier: NCT02200770.

Lymphocyte Subsets Are Associated with Disease Status in Neuromyelitis Optica Spectrum Disorders

OBJECTIVE

At present, studies on lymphocytes are mostly conducted on CD19+ B cells and CD27+ B cells in neuromyelitis optica spectrum disorders (NMOSDs), but the exact changes in lymphocyte subsets (CD19+ B cells, CD3+ T cells, CD4+ Th cells, CD8+ Ts cells, the CD4+/CD8+ ratio, and NK [CD56+ CD16] cells) have rarely been studied. This study aimed to assess lymphocyte subset changes in patients with NMOSD.

METHODS

We performed a cross-sectional study of consecutive patients with acute NMOSD (n = 41), chronic NMOSD (n = 21), and healthy individuals (n = 44). Peripheral blood samples were obtained upon admission, and lymphocyte subsets were analyzed by flow cytometry. Levels of lymphocyte subsets among 3 groups were compared and its correlation with the length of spinal cord lesions was analyzed.

RESULTS

The levels of peripheral blood CD19+ B cells were significantly higher in patients with acute and chronic NMOSD than in healthy controls (HCs) (17.91 ± 8.7%, 13.08 ± 7.562%, and 12.48 ± 3.575%, respectively; p < 0.001) and were positively correlated with the length of spinal cord lesions in acute NMOSD (r = 0.433, p < 0.05). The peripheral blood CD4+/CD8+ ratio was significantly lower in patients with acute NMOSD and chronic NMOSD than in HCs (1.497 ± 0.6387, 1.33 ± 0.5574, and 1.753 ± 0.659, respectively; p < 0.05), and the levels of peripheral blood NK (CD56+ CD16) cells were significantly lower in patients with acute and chronic NMOSD than in HCs (13.6 ± 10.13, 11.11 ± 7.057, and 14.7 [interquartile range = 9.28], respectively; p < 0.01).

CONCLUSIONS

The levels of certain subsets of peripheral blood lymphocytes are associated with disease status in NMOSD.

Adverse events of rituximab in neuromyelitis optica spectrum disorder: a systematic review and meta-analysis

Background:

The adverse events (AEs) of rituximab (RTX) for neuromyelitis optica spectrum disorder (NMOSD) are incompletely understood.

Aim:

To collate information on the reported the AEs of RTX in NMOSD and assess the quality of evidence.

Methods:

PubMed, EMBASE, Web of Science, Cochrane Library, Wanfang Data, CBM, CNKI, VIP, clinicaltrials.gov, and so on were searched for studies with control groups as well as for case series that had assessed the RTX-associated AEs. The incidence of AEs and the comparison of AE risks among different therapies were pooled. The GRADE was developed for evidence quality.

Results:

A total of 3566 records were identified. Finally, 36 studies (4 RCTs, 6 crochet studies, 2 NRCTs, and 24 case series), including 1542 patients (1299 females and 139 males), were included for final analyses. Rates of patients with any AEs, any serious AEs (SAEs), infusion-related AEs, any infection, respiratory infection, urinary infection, and death were 28.57%, 5.66%, 27.01%, 17.36%, 4.76%, 4.76%, and 0.17%, respectively. The results from subgroup analysis showed that AE rates were most likely not associated with covariates such as duration of illness and study designs. Very low-quality evidence suggested that the risk ratios (RR) of any AEs (0.84, 95% CI = 00.42–1.69, p = 0.62) and any infections (1.24 95% CI = 0.18–8.61) of RTX were similar to that of azathioprine, and the RR of any AEs of RXT was akin to that of mycophenolate mofetil (0.66, 95% CI = 0.32–1.35 p = 0.26). Evidence of low to high quality showed the lower RR of RTX in other AEs, but not in infusion-related AEs. Strategies to handle AEs focused on symptomatic treatments.

Conclusions:

RTX is mostly safer than other immunosuppressants in NMOSD: the incidence of RTX-associated AEs was not high, and when present, the AEs were usually mild or moderate and could be well controlled. Given its efficacy and safety, RTX could be recommended as a first-line treatment for NMOSD.

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.

Hope for patients with neuromyelitis optica spectrum disorders - from mechanisms to trials

Neuromyelitis optica spectrum disorder (NMOSD) is a rare inflammatory CNS disease that primarily manifests as relapsing episodes of severe optic neuritis and myelitis. Diagnosis of NMOSD is supported by the detection of IgG autoantibodies that target the aquaporin 4 (AQP4) water channel, which, in the CNS, is an astrocyte-specific protein. AQP4 antibody binding leads to AQP4 internalization, complement-dependent and antibody-dependent cellular cytotoxicity, and water channel dysfunction. Cumulative attack-related injury causes disability in NMOSD, so the prevention of attacks is expected to prevent disability accrual. Until recently, no regulator-approved therapies were available for NMOSD. Traditional immunosuppressant therapies, including mycophenolate mofetil, azathioprine and rituximab, were widely used but their benefits have not been assessed in controlled studies. In 2019 and 2020, five phase II and III randomized placebo-controlled trials of four mechanism-based therapies for NMOSD were published and demonstrated that all four effectively prolonged the time to first relapse. All four drugs were monoclonal antibodies: the complement C5 antibody eculizumab, the IL-6 receptor antibody satralizumab, the B cell-depleting antibody inebilizumab, which targets CD19, and rituximab, which targets CD20. We review the pathophysiology of NMOSD, the rationale for the development of these mechanism-based drugs, the methodology and outcomes of the five trials, and the implications of these findings for the treatment of NMOSD.

Effective Rituximab Treatment in Patients with Neuromyelitis Optica Spectrum Disorders Compared with Azathioprine and Mycophenolate

Introduction

As an autoimmune central nervous system disease characterized by inflammation and demyelination, neuromyelitis optica (NMO) has been extensively investigated. A specific antigenic target, astrocytic water channel aquaporin-4 (AQP4) has already been identified, and it can be recognized explicitly by the autoantibody marker NMO-IgG. Along with the immune attacks, clinical disabilities would gradually accumulate. As there has been no validated and well-recognized therapy for NMO till now, preventing and postponing attack using immunosuppressive therapies is the primary treatment option.

Methods

In the current retrospective study, the effect of immunosuppressive agents was investigated through a long-term follow-up. To assess the long-term effectiveness and safety of rituximab (RTX), azathioprine (AZA), and mycophenolate mofetil (MMF) therapies, all 129 patients with NMO spectrum disorders (NMOSD) who received at least one of these treatments were studied, including 55 seropositive for AQP4-Ab and 74 seronegative for AQP4-Ab.

Results

The median post-treatment annualized relapse rate (ARR) was lower than the pre-treatment rates in all AQP4⁺Ab groups (from 1.0 to 0.7 in RTX, from 0.8 to 0.3 in AZA, and from 0.85 to 0.35 in MMF). Meanwhile, the ARR also decreased in all AQP4⁻Ab groups (from 0.3 to 0.2 in RTX, from 0.9 to 0.5 in AZA, and from 0.9 to 0.4 in MMF). Disability condition improved in the Expanded Disability Status Scale (EDSS) in all AQP4⁺Ab groups (from 4.0 to 2.75 in RTX, from 3.5 to 2.5 in AZA, and from 3.0 to 2.0 in MMF) and in all AQP4⁻Ab groups (from 3.0 to 2.5 in RTX, from 3.0 to 2.5 in AZA, and from 3.5 to 2.0 in MMF). There was no statistically significant difference between the post-treatment and pre-treatment changes of EDSS and ARR in the RTX, AZA, and MMF groups (P > 0.05). However, according to Kaplan–Meier survival analysis, RTX-treated patients were more likely to be relapse-free after long-term follow-up than those who received AZA or MMF therapy. Meanwhile, adverse effects were noted in three out of 23 patients with RTX treatment, five of 32 with AZA treatment, and three of 21 with MMF treatment. No serious adverse events were observed in all treatment groups during the study.

Conclusions

RTX, AZA, and MMF therapies efficiently lowered the relapse frequency and disability in both of the AQP4-Ab seropositive or seronegative patients with NMO. Furthermore, low dosage of RTX is recommended for the patients with NMO owing to its long-term effectiveness and safety.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00298-5.

Immunosuppression in Multiple Sclerosis and Other Neurologic Disorders

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by peripheral immune cell infiltration into the brain and spinal cord, demyelination, glial cell activation, and neuronal damage. Currently there is no cure for MS, however, available disease-modifying agents minimize inflammation in the CNS by various mechanisms. Approved drugs lessen severity of the disease and delay disease progression, however, they are still suboptimal as patients experience adverse effects and varying efficacies. Additionally, there is only one disease-modifying therapy available for the more debilitating, progressive form of MS. This chapter focuses on the presently-available therapeutics and, importantly, the future directions of MS therapy based on preclinical studies and early clinical trials. Immunosuppression in other neurological disorders including neuromyelitis optica spectrum disorders, myasthenia gravis, and Guillain-Barré syndrome is also discussed.

B-Cell Targeted Treatments for Neuromyelitis Optica Spectrum Disorder: A Focus on CD19 and CD20

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing autoimmune disease of the central nervous system that preferentially targets the optic nerves and spinal cord, leading to visual loss and impaired mobility. Until 2019, no medications were FDA-approved for NMOSD treatment, and standard of care was based on mostly empiric and retrospective data. Therapies that target B cells emerged as a treatment strategy due to their fundamental role in disease pathogenesis. We explore different monoclonal antibodies directed at either CD20+ or CD19+ B cells that may have utilization in the treatment of NMOSD, discussing what is known regarding their efficacy and safety.

Treatment of Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune central nervous system (CNS) inflammatory disorder that can lead to serious disability and mortality. Females are predominantly affected, including those within the reproductive age. Most patients develop relapsing attacks of optic neuritis; longitudinally extensive transverse myelitis; and encephalitis, especially brainstem encephalitis. The majority of NMOSD patients are seropositive for IgG autoantibodies against the water channel protein aquaporin-4 (AQP4-IgG), reflecting underlying aquaporin-4 autoimmunity. Histological findings of the affected CNS tissues of patients from in-vitro and in-vivo studies support that AQP4-IgG is directly pathogenic in NMOSD. It is believed that the binding of AQP4-IgG to CNS aquaporin-4 (abundantly expressed at the endfoot processes of astrocytes) triggers astrocytopathy and neuroinflammation, resulting in acute attacks. These attacks of neuroinflammation can lead to pathologies, including aquaporin-4 loss, astrocytic activation, injury and loss, glutamate excitotoxicity, microglial activation, neuroinflammation, demyelination, and neuronal injury, via both complement-dependent and complement-independent pathophysiological mechanisms. With the increased understanding of these mechanisms underlying this serious autoimmune astrocytopathy, effective treatments for both active attacks and long-term immunosuppression to prevent relapses in NMOSD are increasingly available based on the evidence from retrospective observational data and prospective clinical trials. Knowledge on the indications and potential side effects of these medications are essential for a clear evaluation of the potential benefits and risks to NMOSD patients in a personalized manner. Special issues such as pregnancy and the coexistence of other autoimmune diseases require additional concern and meticulous care. Future directions include the identification of clinically useful biomarkers for the prediction of relapse and monitoring of the therapeutic response, as well as the development of effective medications with minimal side effects, especially opportunistic infections complicated by long-term immunosuppression.

Compressive epidural fluid collection secondary to varicella zoster transverse myelitis

Transverse myelitis is often clinically indistinguishable from compressive myelopathies that require emergent neurosurgical intervention. Here, we present a case of acute varicella zoster virus transverse myelitis that was associated with a compressive fluid collection on magnetic resonance imaging (MRI) requiring emergent operative intervention. To our knowledge, this is the first reported case of acute transverse myelitis and a compressive cord lesion in the adult population.

The efficacy of rituximab in patients with neuromyelitis optica spectrum disorder: A real-world study from Turkey

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) are a group of antibody-mediated chronic inflammatory diseases of the central nervous system. Rituximab is a monoclonal antibody that leads to a reduction in disease activity.

OBJECTIVE

To evaluate the efficacy of rituximab as monotherapy in NMOSD and to determine whether the efficacy varies depending on the presence of antibodies in this cohort.

METHOD

This multicentre national retrospective study included patients with NMOSD treated with rituximab at least for 12 months from Turkey. The primary outcomes were the change in the annualised relapse rate, the Expanded Disability Status Scale (EDSS), the number of relapse and radiological activity-free patients.

RESULTS

A total of 85 patients with NMOSD were included in the study. Of 85 patients, 58 (68.2%) were seropositive for anti-Aquaporin4-IgG (antI-AQP4-IgG). All patients were Anti-Myelin Oligodendrocyte Glycoprotein IgG (anti-MOG-IgG) negative. The median follow-up for rituximab treatment was 21 months (Q1 16-Q3 34.5). During rituximab treatment, the mean annualised relapse rate (ARR) significantly decreased from 1.45 ± 1.53 to 0.15 ± 0.34 (P < .001). In subgroup analyses, the mean ARR decreased from 1.61 ± 1.65 to 0.20 ± 0.39 in the seropositive group and 1.10 ± 1.19 to 0.05 ± 0.13 in the seronegative group. The mean EDSS improved from 3.98 ± 2.04 (prior to treatment onset) to 2.71 ± 1.59 (at follow-up) (P < .001). In the seropositive group, mean EDSS decreased from 3.94 ± 1.98 to 2.67 ± 1.54, and in the seronegative group, mean EDSS decreased from 4.07 ± 2.21 to 2.79 ± 1.73. There was no significant difference between anti-AQP4-IgG (+) and (-) groups in terms of ARR and EDSS. Sixty-four patients (75.2%) were relapse-free after the initiation of treatment. Seventy patients (82.3%) were radiological activity-free in the optic nerve, area postrema and brainstem. Additionally, 78 patients (91.7%) showed no spinal cord involvement after the treatment.

CONCLUSION

Rituximab therapy is efficacious in the treatment of Turkish NMOSD patients independent of the presence of the anti-AQP4-IgG antibody.

Targeting Neuromyelitis Optica Pathogenesis: Results from Randomized Controlled Trials of Biologics

Advances in neuromyelitis optica spectrum disorder pathogenesis have allowed the development of targeted drugs. These treatments act on core elements of the disease, including the pro-inflammatory IL-6 pathway (tocilizumab and satralizumab), B cells (rituximab and inebilizumab), and complement (eculizumab). According to recent phase II-III trials, biologics significantly reduced the risk of relapses in aquaporin-4-seropositive patients, whereas results were less striking in the small cohorts of aquaporin-4-seronegative patients. Most adverse events were mild to moderate, with systemic symptoms (headache, arthralgia) or infections (upper respiratory and urinary tracts) being most commonly reported.

EBI2-expressing B cells in neuromyelitis optica spectrum disorder with AQP4-IgG: Association with acute attacks and serum cytokines

Epstein-Barr virus-induced G-protein coupled receptor 2 (EBI2) is important in regulating B cell activation. We investigated whether EBI2 expression on B cells is associated with acute attacks in neuromyelitis optica spectrum disorder with aquaporin-4 IgG (AQP4-IgG(+) NMOSD). Blood samples were collected from patients with AQP4-IgG(+) NMOSD, multiple sclerosis (MS), and patients without inflammatory demyelinating diseases (non-IDD controls). CD19+ B cells and CD4+ T cells were analyzed for surface expression of EBI2. Serum cytokine levels were also analyzed. The EBI2+CD19+ to EBI2-CD19+ cell ratio was significantly higher in patients with AQP4-IgG(+) NMOSD enrolled within 2 months of an attack than in those with non-IDDs (p = 0.007) and MS (p = 0.003). Patients with AQP4-IgG(+) NMOSD enrolled within 2 months of an attack had a higher EBI2+CD19+ cell frequency than patients with AQP4-IgG(+) NMOSD enrolled 2 months after a recent attack (p = 0.001). The EBI2+CD19+ cell frequency was positively correlated with interleukin (IL)-6 and IL-10. EBI2 expression on B cells could be associated with acute attacks of AQP4-IgG(+) NMOSD, possibly through IL-6- or IL-10-related pathways.

A comparison of the effects of rituximab versus other immunotherapies for MOG-IgG-associated central nervous system demyelination: A meta-analysis

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOG-AD) is now recognised as a nosological entity with specific clinical and paraclinical features to aid early diagnosis. Rituximab (RTX) is a chimeric monoclonal antibody directed against CD20 epitope expressed on pre-B and mature B cells and is used to treat B-cell-derived lymphoid neoplasms and antibody-mediated autoimmune diseases. In this review, we performed a meta-analysis to evaluate RTX efficacy and assessed the treatment efficacies based on relapse rates.

METHODS

This study was conducted according to the PRISMA (Preferred Reporting Items for Systemic review and Meta-Analysis) statement. We searched for publications on the PubMed, Embase, Cochrane Library, clinical trials up to December 2020. We compiled 5 studies, Meta-analysis forest plots was conducted for the ARR ratio change pre and post-treatment between rituximab and other disease modifying drugs. A sensitivity analysis was performed with mean difference (MD) of the efficacy of RTX versus other immunotherapies and subgroup analysis was also performed based on site of study.

RESULTS

A meta-analysis of 5 studies with 239 participants was conducted. Patients have received rituximab were recorded in 82 of 239 (34.31%). The mean difference of ARR ratio of rituximab therapy versus other immunotherapies was 0.16 (95%CI, -0.15 to 0.47). No studies found to significantly affect heterogeneity. No major differences occurred in 9.2% of China patients (95% CI: -0.20-1.86; I2=0%) and 90.8% of non- China patients (95% CI: -0.24-0.42; I2=0%). Meanwhile there was no significant subgroup difference (p = 0.18) between them.

CONCLUSION

RTX reduces the relapse frequency in most patients with MOG antibody disease, but there is no differences between rituximab and other immunotherapies in MOG antibody disease. Future a large multicenter randomized controlled clinical trial to thoroughly characterize the efficacy of rituximab for MOG antibody disease is necessary.