Efficacy and safety of rituximab in pediatric neuromyelitis optica

Therapeutic Response in Pediatric Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND OBJECTIVE

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune condition, which can lead to significant disability, and up to 3%-5% of the cases have a pediatric onset. There are limited studies to guide physicians in disease-modifying treatment (DMT) choices for children with NMOSD.

METHODS

This retrospective cohort study evaluated children with NMOSD cases followed at 12 clinics in the US Network of Pediatric MS Centers. Cases were classified as aquaporin-4 antibody positive (AQP4+) and double seronegative (DS) when negative for AQP4+ and for myelin oligodendrocyte glycoprotein (MOG) antibody. The effect of initial DMTs including rituximab, mycophenolate, azathioprine, and IV immunoglobulin (IVIg) on the annualized relapse rate (ARR) was assessed by negative binomial regression. Time to disability progression (EDSS score increase ≥1.0 point) was modeled with a Cox proportional-hazards model.

RESULTS

A total of 91 children with NMOSD were identified: 77 AQP4+ and 14 DS (85.7% females; 43.2% White and 46.6% African American). Eighty-one patients were started on a DMT, and 10 were treatment naive at the time of the analysis. The ARR calculated in all serogroups was 0.25 (95% CI 0.13-0.49) for rituximab, 0.33 (95% CI 0.19-0.58) for mycophenolate, 0.40 (95% CI 0.13-1.24) for azathioprine, and 0.54 (95% CI 0.28-1.04) for IVIg. The ARR in the AQP4+ subgroup was 0.28 (95% CI 0.14-0.55) for rituximab, 0.39 (95% CI 0.21-0.70) for mycophenolate, 0.41 (95% CI 0.13-1.29) for azathioprine, and 0.54 (95% CI 0.23-1.26) for IVIg. The ARR in the treatment-naive group was 0.97 (95% CI 0.58-1.60) in all serogroups and 0.91 (95% CI 0.53-1.56) in the AQP4+ subgroup. None of the initial DMT had a statistically significant effect on EDSS progression.

DISCUSSION

The use of DMTs, particularly rituximab, is associated with a lowered annualized relapse rate in children with NMOSD AQP4+.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that use of disease-modifying treatments is associated with a lowered annualized relapse rate in children with NMOSD AQP4+.

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.

Pediatric Neuromyelitis Optica Spectrum Disorder: Case Series and Literature Review

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a central nervous system (CNS) inflammatory demyelinating disease characterized by recurrent inflammatory events that primarily involve optic nerves and the spinal cord, but also affect other regions of the CNS, including hypothalamus, area postrema and periaqueductal gray matter. The aquaporin-4 antibody (AQP4-IgG) is specific for NMOSD. Recently, myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) have been found in a group of AQP4-IgG negative patients. NMOSD is rare among children and adolescents, but early diagnosis is important to start adequate therapy. In this report, we present cases of seven pediatric patients with NMOSD and we review the clinical and neuroimaging characteristics, diagnosis, and treatment of NMOSD in children.

The Spectrum of Inflammatory Acquired Demyelinating Syndromes in Children

Acquired demyelinating syndromes in childhood comprise a spectrum of monophasic and recurrent inflammatory conditions of the central nervous system. Examples of monophasic conditions include, clinically isolated syndromes such as optic neuritis and transverse myelitis, as well as acute disseminated encephalomyelitis, whereas recurrent disorders include entities such as multiple sclerosis and neuromyelitis optica spectrum disorder. Knowledge about these disorders has expanded due to rigorously evaluated diagnostic criteria, magnetic resonance imaging features, outcomes, and serum biomarkers in these disorders. This review aims to provide a summary of clinical developments in pediatric acquired demyelinating syndromes, with a special focus on diagnostic criteria, neuroinflammatory markers, burden of disease in addition to current and potential future treatment options.

Monoclonal antibody therapy for neuromyelitis optica spectrum disorder: current and future

Monoclonal-antibody has been used for patients with autoimmune disorders for several years, and efficacy and safety were appreciated for these patients. Neuromyelitis optica specturm disorder (NMOSD) has been defined as an autoimmune demyelination disorder of the central nervous system (CNS) with a course of relapse-remission. Treatment of prevention is important for patients with NMOSD because of the increased disability after several attacks. Multiple factors were involved in the pathogenesis of NMOSD. Currently, targeting specific factor was favored in the research into the treatment for NMOSD. Previous studies reported the efficacy and tolerance in NMOSD for drugs such as rituximab, tocilizumab, and eculizumab. The aim of this article is to review the current monoclonal therapies for NMOSD patients, and also future alternative options.

An update on the evidence for the efficacy and safety of rituximab in the management of neuromyelitis optica

Neuromyelitis optica spectrum disorders (NMOSDs) is a new concept which includes classical neuromyelitis optica (NMO) and partial forms of NMO such as recurrent optic neuritis with positive aquaporin-4 antibodies (AQP4) or brainstem symptoms (intractable hiccups or vomiting). This disease is clearly distinguished from multiple sclerosis (MS) and the therapeutic approach is clearly different. Rituximab is actually considered to be one of the most efficient treatments of NMOSD, even if class I studies are clearly lacking. In the present review, we describe the state of the art about rituximab treatment in NMOSD, including adults and children, plus its efficacy and tolerance and we also underline the questions that should be addressed in the near future.

Anti-B-Cell Therapies in Autoimmune Neurological Diseases: Rationale and Efficacy Trials

B cells have an ever-increasing role in the etiopathology of a number of autoimmune neurological disorders, acting as antibody-producing cells and, most importantly, as sensors, coordinators, and regulators of the immune response. B cells, among other functions, regulate the T-cell activation process through their participation in antigen presentation and production of cytokines. The availability of monoclonal antibodies or fusion proteins against B-cell surface molecules or B-cell trophic factors bestows a rational approach for treating autoimmune neurological disorders, even when T cells are the main effector cells. This review summarizes basic aspects of B-cell biology, discusses the role(s) of B cells in neurological autoimmunity, and presents anti-B-cell drugs that are either currently on the market or are expected to be available in the near future for treating neurological autoimmune disorders.

[Evidence of treatment of chronic inflammation in childhood and adolescence with biologics]

BACKGROUND

Biologics, usually monoclonal antibodies or fusion proteins, are thought to specifically interfere with immunopathogenesis of chronic inflammatory diseases. In order to test these substances also in children and adolescents, financial incentives for manufacturers were created and classification of chronic inflammatory diseases and definition of disease activity, improvement, relapse and remission were established and large international research cooperation projects were founded.

METHODS

A selective literature search was carried out for treatment of chronic inflammatory diseases in children and adolescents with biologics including current guidelines.

RESULTS

Only 7 out of 18 prescribed biologics have been approved for children and mostly within narrow limits. The evidence for efficacy is based on four randomized double blind placebo-controlled studies, seven withdrawal studies and seven observational studies. In spite of the limited evidence in comparison to their use in adult patients these substances are broadly used worldwide and have enlarged and substantially improved the therapeutic choices in children when conventional treatment failed or proved to be toxic. Severe adverse events including infections occasionally occur (0.01-0.03 events per patient year) but the rate of malignancies is not obviously increased; however, only two thirds of patients respond to treatment. Improvement is often incomplete, some patients deteriorate and definite termination of drug treatment is possible in only a few patients.

CONCLUSION

As the prescription of biologics has become an important issue of treatment but is based on insufficient evidence data, further studies are necessary in children and adolescents with diseases, such as juvenile idiopathic arthritis, Crohn's disease, ulcerative colitis and inherited fever syndromes. As many drugs are available these studies can be conducted against verum.

Rituximab as a first-line preventive treatment in pediatric NMOSDs: Preliminary results in 5 children

OBJECTIVE

No established therapeutic protocol has been proposed to date for childhood-onset neuromyelitis optica (NMO) spectrum disorders (NMOSDs). We report the response of 5 NMO immunoglobulin (Ig)G-positive pediatric cases to a standardized B-cell-targeted first-line immunosuppressive protocol with rituximab for prevention of relapses.

METHODS

Retrospective observational cohort study.

RESULTS

All patients included in the study showed disease remission after rituximab induction. Relapses always occurred in conjunction with CD19(+) B-cell repopulation and appeared less severe than prior to treatment. At the end of follow-up, neurologic disability and MRI findings stabilized or improved in all the patients, with only minor and transient side effects. Oral steroid discontinuation was possible in all the patients.

CONCLUSIONS

Our protocol is well-tolerated and has provided encouraging results in terms of control of relapses and progression of disability. An early intervention with rituximab might affect the disease course in pediatric NMO-IgG-positive NMOSDs.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for children with NMOSDs, rituximab is well-tolerated and stabilizes or improves neurologic disability.

Individualized rituximab treatment for relapsing neuromyelitis optica: a pediatric case report

BACKGROUND

Neuromyelitis optica is an autoimmune inflammatory disorder of the central nervous system. Current therapeutic approaches are based on small uncontrolled trials, case series, or case reports. There are only a few case reports describing rituximab for pediatric neuromyelitis optica.

PATIENT

A 7-year-old girl with neuromyelitis optica had high disease activity with recurrent myelitis and steroid dependence. A remarkable increase of CD19(+) B-cell count in the peripheral blood mononuclear cells and seropositivity for anti-aquaporin 4 antibody were detected at each attack. After induction therapy with rituximab, the CD19(+) B-cell number was significantly reduced and sustained at low levels. The level of serum anti-aquaporin 4 antibody normalized. She was relapse-free over 1-year follow-up period. An individualized maintenance therapy scheme is underway.

CONCLUSION

Treatment with rituximab for relapsing neuromyelitis optica requires an individualized regimen to optimize the frequency and dosage of administration to maximize efficacy yet minimize overtreatment and cost. Personal levels of CD19(+) B cells in peripheral blood mononuclear cells at previous attacks and responsiveness to rituximab in induction therapy may be two useful indicators in establishing individualized maintenance therapy schemes for relapsing neuromyelitis optica.

Rituximab use in pediatric central demyelinating disease

BACKGROUND

Rituximab is a B-cell therapy used off-label to reduce relapses in adult demyelinating diseases. There is limited knowledge of its clinical use in pediatric neuromyelitis optica and multiple sclerosis. Demyelinating diseases in children can have high morbidity, and B-cell therapies hold promise for those with a severe course. Our study investigates the clinical experience of safety and efficacy with rituximab in children with demyelinating diseases of the central nervous system.

METHODS

This is a retrospective case series of 11 patients with pediatric neuromyelitis optica and multiple sclerosis who received at least one rituximab infusion at the Pediatric Multiple Sclerosis Clinic, University of California, San Francisco. Each patient was infused up to 1000 mg twice 2 weeks apart. Patients were monitored prospectively, and relapse events, laboratories, and adverse reactions were recorded.

RESULTS

Eight children with neuromyelitis optica, two with relapsing-remitting multiple sclerosis and one with secondary-progressive multiple sclerosis received rituximab treatment. The median number of cycles was 3. Most patients (82%, n = 9) experienced reduction of relapses after initiating rituximab. There were no serious infections. Infusion reactions were reported in three patients and managed successfully in subsequent infusions with increased pretreatment (dexamethasone and diphenhydramine) and use of slower infusion rates. Rituximab was not discontinued in any child because of side effects; two switched treatment therapy after 4.5 and 11 months because of relapses.

CONCLUSIONS

The use of rituximab in our pediatric neuromyelitis optica and multiple sclerosis cohort was overall safe and effective. Larger studies should confirm our observations.

Unilateral visual loss in a previously healthy 15-year-old girl: monosymptomatic neuromyelitis optica?

We report a previously healthy 15 year old girl with acute onset of unilateral visual loss consistent with a diagnosis of monosymptomatic optic neuritis. Her symptoms responded well to the use of high-dose intravenous methylprednisolone. With very brief follow-up (2 months) she has had no subsequent difficulties. However, testing was positive for the presence of anti-aquaporin-4 antibodies in both serum and cerebrospinal fluid, which have been associated with neuromyelitis optica (NMO). While NMO antibodies lack complete sensitivity, there is high degree of specificity. Our patient does not meet currently accepted diagnostic criteria for NMO, but is likely at high-risk to develop myelitis or recurrent optic neuritis. There are no evidence-based guidelines for whether this patient should undergo disease-modifying treatment. Based upon the high-risk for clinical relapse, we have recommended immunosuppressive therapy with rituximab (anti-B cell monoclonal antibodies). While randomized trials for patients with this clinical scenario are unlikely, observational studies of a cohort of such patients would provide better guidance on the natural history and merits of disease-modifying therapy.

Neuromyelitis optica in child: diagnostic and therapeutic challenges

Neuromyelitis optica (NMO) is a rare syndrome of severe inflammatory demyelination of the central nervous system, causing attacks of optic neuritis and transverse myelitis. Although uncommon, attention should be given to the proper identification and management of the affected patients. We present a case of a 13-year-old girl with severe neuromyelitis optica. The patient's initial presentation consisted of encephalopathy and optic neuritis. Approximately 2 months later, coinciding with the weaning of steroid treatment, she presented with ascending paralysis and respiratory failure. She was seropositive for NMO-IgG. Treatment included intravenous immune globulin, steroids, plasmapheresis, and rituximab and was complemented with proper nutrition, vitamins, minerals, and intense rehabilitation. Two years after the initial presentation and one short relapse, the patient has made a remarkable recovery without neurologic deficit. This report underscores the difficulty in making the initial diagnosis, choosing the best treatment, and the need for more streamlined pediatric guidelines for diagnosis, treatment, and prevention of relapses of pediatric NMO.

Monitoring neuromyelitis optica activity

Neuromyelitis optica (NMO) is a demyelinating and inflammatory disease essentially restricted to the spinal cord and the optic nerves. Emerging evidence indicates that serum antiaquaporin-4 (AQP4) antibodies have a critical role in its pathogenesis. NMO courses with multiple relapses, often leading to severe disability. Management of NMO focuses on the effective treatment of acute attacks and the prevention of relapses. The latter is currently attempted with immunosuppressive drugs. Although several factors have been associated with disease activity, especially serum levels of anti-AQP4 IgG, no single one of them has been proved clinically useful for guiding treatment. New drugs that target specifically AQP4 antibodies and complement activation are being developed; they may prove to be more efficient with fewer side effects.

Seropositive neuromyelitis optica: a pediatric case report and 6-year follow-up

BACKGROUND

Neuromyelitis optica is an autoimmune demyelinating disorder of the central nervous system. Although it has some features in common with multiple sclerosis, it has different clinical features, prognosis, and treatment. We describe a boy with seropositive neuromyelitis optica and his 6-year follow-up.

PATIENT

A boy aged 5 years 8 months presented with relapsing optic neuritis, short segment transverse myelitis, and brain involvement. He met the diagnostic criteria for multiple sclerosis fulfilling the McDonald 2010 criteria; however, neuromyelitis optica immunoglobulin-G was detected, and the patient was diagnosed with neuromyelitis optica. He had frequent relapses until immunosuppressive treatment with azathioprine and low-dose prednisone was started. After he was asymptomatic for 2.5 years, prednisone was withdrawn, but he had a new attack soon after withdrawal of the steroid.

CONCLUSIONS

It is important to differentiate neuromyelitis optica from multiple sclerosis because early immunosuppressive treatment prevents further disability, and longer periods of immunosuppressive treatment should be planned to prevent relapses.

The spectrum of neuromyelitis optica (NMO) in childhood

The evaluation of inflammatory central nervous system disorders in childhood with predominant involvement of the optic nerves and spinal cord has been greatly enhanced over the last decade with identification of a group of disorders unified by the detection of neuromyelitis optica (NMO)-IgG, an antibody targeting the central nervous system-predominant water channel aquaporin-4. Clinical syndromes are predominated by the relapsing form of NMO but also include encephalopathic variants that can mimic acute disseminated encephalomyelitis. Maintenance immunotherapy is used to prevent relapses in NMO-IgG-seropositive patients. In contrast, NMO-IgG-seronegative children with NMO more commonly have a monophasic course (simultaneous occurrence of optic neuritis and transverse myelitis) and do not require remission-maintaining immunotherapy, but close surveillance is advised. Current clinical, pathological, and pathogenetic knowledge is reviewed with a focus on clinical presentation, neuroimaging findings, serological investigations, and treatment of children with disorders within the spectrum of central nervous system aquaporin-4 autoimmunity.

Treatment of pediatric optic neuritis

OPINION STATEMENT

Pediatric optic neuritis is a rare disorder causing a subacute loss of vision (often bilateral) in children, often of a severe degree. Common clinical findings include dense visual field loss, afferent pupillary defect (APD) in unilateral cases, and papillitis that is often bilateral. Contrary to optic neuritis in the adult population, the differential diagnosis for this disorder in pediatric patients is quite extensive, so neuroimaging and serologic evaluation are necessary to exclude an infectious or neoplastic process. Pediatric optic neuritis may occur as a clinically isolated syndrome, or in association with diffuse neurologic dysfunction, such as acute disseminated encephalomyelitis (ADEM). Optic neuritis may also be the first episode heralding the onset of pediatric multiple sclerosis or neuromyelitis optica (NMO or Devic's disease). Therefore, formal neurologic evaluation and follow-up are indicated. Although the management of this disorder in adults is well described, there is a paucity of evidence-based, prospective clinical data on its management and treatment in a pediatric population. The current treatment of pediatric optic neuritis consists of 3 to 5 days of intravenous methylprednisolone (4-30 mg/kg per day), followed by a prolonged oral corticosteroid taper. A prolonged course of oral steroid (2-4 weeks) is recommended to avoid recurrence, which is common in this age group. Some controversy persists concerning the exposure of children to high-dose parenteral corticosteroids to treat an entity that is usually self-limited, but given the severity of vision loss in one or both eyes in this population, this intervention is standard in neuro-ophthalmologic practice.

Current options for the treatment of optic neuritis

Optic neuritis can be defined as typical (associated with multiple sclerosis, improving independent of steroid treatment), or atypical (not associated with multiple sclerosis, steroid-dependent improvement). Causes of atypical optic neuritis include connective tissue diseases (eg, lupus), vasculitis, sarcoidosis, or neuromyelitis optica. In this manuscript, updated treatment options for both typical and atypical optic neuritis are reviewed. Conventional treatments, such as corticosteroids, therapeutic plasma exchange, and intravenous immunoglobulin therapy are all discussed with commentary regarding evidence-based outcomes. Less commonly used treatments and novel purported therapies for optic neuritis are also reviewed. Special scenarios in the treatment of optic neuritis – pediatric optic neuritis, acute demyelinating encephalomyelitis, and optic neuritis occurring during pregnancy – are specifically examined.

[Neuromyelitis optica in children. Two case reports]

Devic neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system associating acute transverse myelitis and optic neuritis. This is a different disease from multiple sclerosis for which the presence of the NMO antibody directed against aquaporin 4 is a specific marker. Brain damage on MRI does not exclude the diagnosis; the location is superposable in the brain zones rich in aquaporin 4 channels. We report 2 cases of NMO with anti-aquaporin 4. One patient was not symptomatic of brain damage. In this patient, the affinity of anti-NMO for aquaporin 4, studied by flow cytometry, was particularly high. Both patients were treated with immunosuppressive agents (rituximab) due to the failure of or dependence on high-dose corticosteroids.

Update on neuromyelitis optica: natural history and management

Neuromyelitis optica or Devic disease is an inflammatory disorder of the central nervous system. It is caused by antibodies that attack aquaporin 4 water channels in the cell membrane of astrocytic foot processes at the blood brain barrier. It can involve the optic nerve, the spinal cord and beyond. Here we review its pathophysiology, clinical features, and therapy.