Natalizumab in pediatric multiple sclerosis patients

Ectopic Tumor VCAM-1 Expression in Cancer Metastasis and Therapy Resistance

Vascular Cell Adhesion Molecule-1 (VCAM-1; CD106) is a membrane protein that contributes critical physiologic functional roles in cellular immune response, including leukocyte extravasation in inflamed and infected tissues. Expressed as a cell membrane protein, VCAM-1 can also be cleaved from the cell surface into a soluble form (sVCAM-1). The integrin α4β1 (VLA-4) was identified as the first major ligand for VCAM-1. Ongoing studies suggest that, in addition to mediating physiologic immune functions, VCAM-1/VLA-4 signaling plays an increasingly vital role in the metastatic progression of various tumors. Additionally, elevated concentrations of sVCAM-1 have been found in the peripheral blood of patients with cancer, suggesting the tumor microenvironment (TME) as the source of sVCAM-1. Furthermore, over-expression of VLA-4 was linked to tumor progression in various malignancies when VCAM-1 was also up-regulated. This review explores the functional role of VCAM-1 expression in cancer metastasis and therapy resistance, and the potential for the disruption of VCAM-1/VLA-4 signaling as a novel immunotherapeutic approach in cancer, including osteosarcoma, which disproportionately affects the pediatric, adolescent and young adult population, as an unmet medical need.

Early onset multiple sclerosis and the effect of disease onset age on neurological disability in multiple sclerosis

OBJECTIVES

The incidence of early onset multiple sclerosis (EOMS) is increasing. We therefore aimed to compare the demographic, clinical, and magnetic resonance imaging features of early onset and adult onset multiple sclerosis patients. Furthermore, the effects of age of onset were evaluated for patients who reached an expanded disability status scale (EDSS) scores of six.

PATIENTS AND METHODS

This was a retrospective study of MS patient medical charts between 1977 and 2021, which were registered in the MS database. Only patients with relapsing remitting MS longer than 1 year were included in the study. The patients included in the study were divided into the EOMS and adult onset MS (AOMS) groups. General demographic datas, clinical datas such as the characteristics of the first clinical period, the time between the first two attacks, the attack rate in the first 2 and 3 years, the treatment status, the EDSS at the first evaluation, the EDSS score at 6 month intervals, the time to reach an EDSS score of six, and magnetic resonance imaging features such brain and spinal T2 lesions were recorded.

RESULTS

Total of 3477 including 353 (10.2 %) EOMS and 3124 (89.8 %) AOMS patients were analyzed. There was no statistically significant difference in symptom patterns between the EOMS and AOMS groups ( p = 0.649). Supratentorial clinical features at first attack were more common in AOMS patients, while optic neuropathy at first attack was more common in EOMS patients. Using univariable analysis, clinical supratentorial features at first attack, clinical optic neuropathy at first attack, clinical spinal cord at fist attack, spinal cord lesions, first EDSS score, relapse in the first 3 years, and onset patterns in terms of age were found to be statistically significant risk factors. In multivariable-adjusted analysis, clinical supratentorial features at first attack, clinical spinal cord lesions at first attack, first EDSS scores relapses in the first 3 years, and onset patterns in terms of age were found to be independent risk factors for EDSS in reaching a score of six. Early treatment start was associated with reduced hazard rate of reaching an EDSS score of 6.

CONCLUSION

Onset pattern in terms of age was an independent prognostic factor for neurological disabilities in MS patients.

The Economic and Humanistic Burden of Pediatric-Onset Multiple Sclerosis

Background: Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system. Pediatric-onset MS (POMS), defined as onset of MS before 18 years of age, is estimated to account for 2% to 5% of the MS population worldwide. Objectives: To conduct a literature review focused on the healthcare resource utilization and cost as well as quality-of-life (QOL) outcomes among patients with POMS. Methods: We conducted a systematic literature review of English-language studies published after September 2010 in MEDLINE and Embase to describe the global economic healthcare resource utilization and costs and humanistic (QOL) burden in patients with POMS. Results: We found 11 studies that reported on healthcare resource utilization, cost, or insurance coverage and 36 studies that reported on QOL outcomes in patients with POMS. Patients with POMS had higher rates of primary care visits (1.41 [1.29-1.54]), hospital visits (10.74 [8.95-12.90]), and admissions (rate ratio, 4.27 [2.92-6.25];OR, 15.2 [12.0-19.1]) compared with healthy controls. Mean per-patient costs in the United States were $5907 across all settings per year of follow-up between 2002 and 2012; mean costs per hospital stay were $38 543 (in 2015 USD) between 2004 and 2013. Three studies reported psychosocial scores between 71.59 and 79.7, and 8 studies reported physical health scores between 74.62 to 82.75 using the Pediatric Quality of Life Measurement Model (PedsQLTM). Twelve studies used the PedsQL™ Multidimensional Fatigue Scale. Mean scores on the self-reported general fatigue scale ranged from 63.15 to 78.5. Quality-of-life scores were lower than those of healthy controls. Discussion: Our review presents a uniquely broad and recent overview of the global economic and humanistic burden of patients with POMS. Additional research on healthcare resource utilization and cost would provide a more robust understanding of the economic burden in this population. Conclusions: Healthcare resource utilization and costs are high in this population, and patients report reduced QOL and significant fatigue compared with healthy children and adolescents.

Effect of natalizumab treatment on the rate of No Evidence of Disease Activity in young adults with multiple sclerosis in relation to pubertal stage

Approximately 40% of young-onset multiple sclerosis (MS) patients experience breakthrough disease, which carries a high risk for long-term disability, and requires using therapies beyond traditional first-line agents. Despite the increasing use of newer disease-modifying treatments (DMTs) in this population, data are not available to guide the need for escalating DMTs and there is a scarcity of data on the effects of natalizumab in children and young adults with active disease. We performed a retrospective analysis of the rate of No Evidence of Disease Activity (NEDA), tolerability, and safety of natalizumab in a multi-center cohort of 36 children and young adults with highly active MS. All patients had active disease and initiated treatment with natalizumab. The primary endpoint was the rate of achieving NEDA-3 status, within two years of natalizumab treatment. To examine a possible effect of age on the outcome of treatment, outcomes were also analyzed by pre-pubertal (n = 13 children aged 9-13 years) and pubertal subgroups (n = 23 young adolescents aged 14-20 years). The NEDA-3 status of the pre-pubertal group was 92% in the first and second year and in the pubertal group - 96% in the first year and 92% in the second year. Natalizumab reduced the number and volume of brain lesions in both pre-pubertal and pubertal groups. Treatment was well-tolerated, only 8 patients (22.2%) had adverse events during the 2-year study period. Our analysis shows that natalizumab is effective and well-tolerated in pre-pubertal and pubertal MS patients.

Multiple Sclerosis in Children: Differential Diagnosis, Prognosis, and Disease-Modifying Treatment

Pediatric-onset multiple sclerosis (POMS) is a rare neuroinflammatory and neurodegenerative disease that has a significant impact on long-term physical and cognitive patient outcomes. A small percentage of multiple sclerosis (MS) diagnoses occur before the age of 18 years. Before treatment initiation, a careful differential diagnosis and exclusion of other similar acquired demyelinating syndromes such as anti-aquaporin-4-associated neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody spectrum disorder (MOGSD) is warranted. The recent 2017 changes to the McDonald criteria can successfully predict up to 71% of MS diagnoses and have good specificity of 95% and sensitivity of 71%. Additional measures such as the presence of T1-weighted hypointense lesions and/or contrast-enhancing lesions significantly increase the accuracy of diagnosis. In adults, early use of disease-modifying therapies (DMTs) is instrumental to a better long-term prognosis, including lower rates of relapse and disability worsening, and numerous FDA-approved therapies for adult-onset MS are available. However, unlike their adult counterparts, the development, testing, and regulatory approval of POMS treatments have been significantly slower and hindered by logistic and/or ethical considerations. Currently, only two MS DMTs (fingolimod and teriflunomide) have been tested in large phase III trials and approved by regulatory agencies for use in POMS. First-line therapies not approved by the FDA for use in children (interferon-β and glatiramer acetate) are also commonly used and result in a significant reduction in inflammatory activity when compared with non-treated POMS patients. An increasing number of POMS patients are now treated with moderate efficacy therapies such as dimethyl fumarate and high-efficacy therapies such as natalizumab, anti-CD20 monoclonal antibodies, anti-CD52 monoclonal antibodies, and/or autologous hematopoietic stem cell transplantation. These high-efficacy DMTs generally provide additional reduction in inflammatory activity when compared with the first-line medications (up to 62% of relapse-rate reduction). Therefore, a number of phase II and III trials are currently investigating their efficacy and safety in POMS patients. In this review, we discuss potential changes in the regulatory approval process for POMS patients that are recommended for DMTs already approved for the adult MS population, including smaller sample size for pharmacokinetic/pharmacodynamic studies, MRI-centered primary outcomes, and/or inclusion of teenagers in the adult trials.

TyPed study: Natalizumab for the treatment of pediatric-onset multiple sclerosis in Portugal

BACKGROUND

A significant proportion of pediatric-onset multiple sclerosis (POMS) patients do not respond to first-line disease-modifying therapies. Clinical trials showed that natalizumab is effective and safe in adults, but there are limited clinical trial data for children. Natalizumab is currently prescribed off-label for POMS. We aimed to characterize the effectiveness, safety and tolerability of natalizumab in all POMS cases treated in Portugal (from 2007 to 2018).

METHODS

Data from clinical records were retrospectively collected for all POMS cases treated with natalizumab in Portugal.

RESULTS

Twenty-one patients were included, 14 (67%) of which were female. The median age at POMS diagnosis was 13 years old. The median duration of treatment with natalizumab was 2 years and 3 months. Median Expanded Disability Status Scale score decreased from 1.5 to 1.0 after 24 months. The Annualized Relapse Rate decreased from 1.31 events/patient/year before treatment with natalizumab to 0 after 12 months of treatment and to 0.04 after 24 months. No gadolinium-enhancing lesions or new or enlarged T2 hyperintense lesions were observed in 8/8 patients (100%) after 12 months, and 4/5 (80%) after 24 months. There was one possible serious adverse event, which did not require dose adjustment. Five patients discontinued treatment due to positive anti-JCV (JC virus) antibody JC serostatus.

CONCLUSION

Natalizumab may be an effective and safe disease-modifying therapy for POMS. Our results are in line with data published for the adult population, as well as with similar observational studies in pediatric populations in other regions.

Pharmacokinetics and pharmacodynamics of natalizumab in pediatric patients with RRMS

Objective

This phase I study investigated pharmacokinetic (PK) and pharmacodynamic (PD) profiles of natalizumab in pediatric patients with relapsing-remitting MS (RRMS).

Methods

Pediatric patients with RRMS who were prescribed natalizumab 300 mg IV every 4 weeks were enrolled. Blood samples were collected on days 1, 2, 8, 15, and 22 and at weeks 4, 8, 12, and 16 to estimate PK parameters; PD properties were evaluated by measuring α4-integrin saturation and lymphocyte counts over time. Natalizumab's safety profile was also evaluated.

Results

PK parameters were similar to those reported in adult patients; natalizumab concentrations peaked approximately 1 day after infusion in most of the participants (Cmax 142.9 μg/mL, AUClast 47389.4 hr*μg/mL), followed by a biphasic decline with a rapid distribution phase and a slow elimination phase, with a terminal half-life of 215.1 hours. In terms of PD, both time course and magnitude of α4-integrin saturation and increase in lymphocyte counts were similar to those observed in adults. During the 16-week study follow-up, 3 adverse events attributed to natalizumab were observed; no unexpected safety events occurred.

Conclusions

PK profile, α4-integrin saturation, lymphocyte counts, and safety observed in these pediatric patients are comparable to those reported in adults.

Classification of evidence

This study provides Class I evidence that natalizumab PK/PD parameters and safety profile are similar in adults and pediatric patients in the short term. Longer studies, also including a larger number of younger subjects (aged 10-12 years), are required to further inform about long-term PK and PD parameters in pediatric patients with MS.

Pediatric multiple sclerosis: a review

BACKGROUND

Pediatric-onset multiple sclerosis (POMS) prevalence and incidence rates are increasing globally. No disease-modifying therapy are approved for MS pediatric population. Hence, we aim to review the literature on POMS to guide treating physicians on the current understanding of diagnosis and management of pediatric MS.

METHODS

The authors performed a literature search and reviewed the current understanding on risk factors and disease parameters in order to discuss the challenges in assessing and implementing diagnosis and therapy in clinical practice.

RESULTS

The revised International Pediatric MS group diagnostic criteria improved the accuracy of diagnosis. Identification of red flags and mimickers (e.g. acute disseminated encephalomyelitis and neuromyelitis optica) are vital before establishing a definitive diagnosis. Possible etiology and mechanisms including both environmental and genetic risk factors are highlighted. Pediatric MS patients tend to have active inflammatory disease course with a tendency to have brainstem / cerebellar presentations at onset. Due to efficient repair mechanisms at early life, pediatric MS patients tend to have longer time to reach EDSS 6 but reach it at earlier age. Although no therapeutic randomized clinical trials were conducted in pediatric cohorts, open-label multi-center studies reported efficacy and safety results with beta interferons, glatiramer acetate and natalizumab in similar adult cohorts. Several randomized clinical trials assessing the efficacy and safety of oral disease-modifying therapies are ongoing in pediatric MS patients.

CONCLUSION

Pediatric MS has been increasingly recognized to have a more inflammatory course with frequent infratentorial presentations at onset, which would have important implications in the future management of pediatric cohorts while awaiting the results of ongoing clinical trials.

Pediatric Multiple Sclerosis: Genes, Environment, and a Comprehensive Therapeutic Approach

BACKGROUND

Pediatric multiple sclerosis is an increasingly recognized and studied disorder that accounts for 3% to 10% of all patients with multiple sclerosis. The risk for pediatric multiple sclerosis is thought to reflect a complex interplay between environmental and genetic risk factors.

MAIN FINDINGS

Environmental exposures, including sunlight (ultraviolet radiation, vitamin D levels), infections (Epstein-Barr virus), passive smoking, and obesity, have been identified as potential risk factors in youth. Genetic predisposition contributes to the risk of multiple sclerosis, and the major histocompatibility complex on chromosome 6 makes the single largest contribution to susceptibility to multiple sclerosis. With the use of large-scale genome-wide association studies, other non-major histocompatibility complex alleles have been identified as independent risk factors for the disease. The bridge between environment and genes likely lies in the study of epigenetic processes, which are environmentally-influenced mechanisms through which gene expression may be modified.

CONCLUSIONS

This article will review these topics to provide a framework for discussion of a comprehensive approach to counseling and ultimately treating the pediatric patient with multiple sclerosis.

Therapy of highly active pediatric multiple sclerosis

Objective:

Study aims were to determine the frequency of highly active disease in pediatric multiple sclerosis (MS), the response to natalizumab (NTZ) and fingolimod (FTY) treatment, and the impact of current treatment modalities on the clinical course.

Methods:

Retrospective single-center study in the German Center for MS in Childhood and Adolescence.

Results:

Of 144 patients with first MS manifestation between 2011 and 2015, 41.6% fulfilled the criteria for highly active MS. In total, 55 patients treated with NTZ and 23 with FTY demonstrated a significant reduction in relapse rate (NTZ: 95.2%, FTY: 75%), new T2 lesions (NTZ: 97%, FTY: 81%), and contrast-enhancing lesions (NTZ: 97%, FTY: 93%). However, seven patients switched from NTZ to FTY experienced an increase in disease activity. Comparing pediatric MS patients treated in 2005 with those treated in 2015 showed a 46% reduction in relapse rate and a 44% reduction in mean Expanded Disability Status Scale (EDSS).

Conclusion:

The rate of highly active disease among pediatric MS patients is high; more than 40% in our cohort. Response to NTZ and FTY treatment is similar if not better than observed in adults. Current treatment modalities including earlier treatment initiation and the introduction of NTZ and FTY have significantly improved the clinical course of pediatric MS.

Therapeutic Approach to the Management of Pediatric Demyelinating Disease: Multiple Sclerosis and Acute Disseminated Encephalomyelitis

Acquired pediatric demyelinating diseases manifest acutely with optic neuritis, transverse myelitis, acute disseminated encephalomyelitis, or with various other acute deficits in focal or polyfocal areas of the central nervous system. Patients may experience a monophasic illness (as in the case of acute disseminated encephalomyelitis) or one that may manifest as a chronic, relapsing disease [e.g., multiple sclerosis (MS)]. The diagnosis of pediatric MS and other demyelinating disorders of childhood has been facilitated by consensus statements regarding diagnostic definitions. Treatment of pediatric MS has been modeled after data obtained from clinical trials in adult-onset MS. There are now an increasing number of new therapeutic agents for MS, and many will be formally studied for use in pediatric patients. There are important efficacy and safety concerns regarding the use of these therapies in children and young adults. This review will discuss acute management as well as chronic immunotherapies in acquired pediatric demyelination.

Natalizumab in the pediatric MS population: results of the Italian registry

Background

Natalizumab is a promising option for pediatric multiple sclerosis (MS) patients with active evolution and a poor response to Interferon-beta or Glatiramer Acetate. However, no data are available in large cohorts of patients and after a long-term follow up. Our study was planned to shed lights on this topic.

Methods

A registry was established in 2007 in Italy to collect MS cases treated with Natalizumab (NA) before 18 years of age.

Results

101 patients were included (69 females), mean age of MS onset 12.9 ± 2.7 years, mean age at NA initiation 14.7 ± 2.4 years. Mean treatment duration was 34.2 ± 18.3 months.

During NA treatment, a total of 15 relapses were recorded in 9 patients, annualized relapse rate was 2.3 ± 1.0 in the year prior to NA and decreased to 0.1 ± 0.3 (p < 0.001) at last NA infusion.

Mean Expanded Disability Status Scale (EDSS) decreased from 2.6 ± 1.3 at initiation of NA to 1.8 ± 1.2 at the time of last visit (p < 0.001). At brain MRI, new T2 or Gd enhancing lesions were observed in 10/91 patients after 6 months, 6/87 after 12 months, 2/61 after 18 months, 2/68 after 24 months, 3/62 after 30 months, and 5/43 at longer follow up. At the time of last observation, 58 % of patients were free from clinical (relapses/increased EDSS) and/or MRI activity (new T2 or gadolinium-enhancing lesions). No relevant adverse events were recorded.

Discussion

NA was safe, well tolerated and very efficacious in the large majority of patients. Our data support the use of this medication in subjects with pediatric MS and an aggressive course.

Conclusions

A relevant reduction of relapse rate and EDSS was observed during NA treatment, compared to pre-treatment period. No evidence of disease activity (NEDA) occurred in 58 % of cases.

Treatment of multiple sclerosis in children and its challenges

Though pediatric-onset multiple sclerosis (MS) is a rare disease, providers must be aware of the diagnosis, and of symptoms that herald demyelination, in order to initiate prompt workup and treatment in the appropriate clinical scenarios. Though children with MS do not have significant physical disability at onset, at least a third of patients have cognitive deficits at the time of diagnosis and demonstrate worsening cognitive functioning over time. Pediatric MS patients tend to have high relapse rates and high lesion volumes early in their disease course and warrant early initiation of disease modifying therapy. This review discusses the different treatment options available for pediatric patients with MS, emerging medications, and some of the challenges associated with treating this patient population.

The usefulness of immunotherapy in pediatric neurodegenerative disorders: A systematic review of literature data

Immunotherapeutic strategies to treat neurodegenerative disorders have inspired the scientific community. The aim of our review is to address the translational aspects of neuroimmunology to describe the efficacy of immunotherapy in the treatment of pediatric neurodegenerative disorders. In the studies we analyzed IVIG were found to be efficient in the treatment of post-streptococcal neurodegenerative disorders, even if in PANDAS, plasma-exchange (PE) showed a higher efficiency. IVIG were also successfully used in ADEM and Guillan-Barré syndrome. In Sydenham Chorea the use of methylprednisolone was found in most cases as efficient as IVIG, while in Tourette's Syndrome, Colecoxib was successfully used in one patient. Pediatric Multiple Sclerosis seems to respond better to immunosuppressant agents (Mitoxantrone, Cyclophosphamide, Natalizumab), as well as Neuromyelitis optica (Rituximab, Mycofenolate). The importance of this review relies in the attempt to draw standardized guidelines for immunotherapy in pediatric neurodegeneratve disorders.

Cognitive deficits in pediatric-onset multiple sclerosis: what does the future hold?

Pediatric-onset multiple sclerosis is relatively rare and research regarding disease characteristics is in its infancy. Regardless, there are a growing number of studies finding early cognitive deficits in this population. There are some similarities in outcomes to those seen in the adult-onset multiple sclerosis population, but also several important differences. With specific regard to cognitive functioning in pediatric-onset multiple sclerosis, there is evidence of deficit in nearly a third of patients, with impairment primarily in areas of processing speed, visual-spatial processing and language. There are additional findings of fatigue and depression that impact functional outcomes requiring further attention in assessment and treatment considerations. This paper also explores other areas requiring increased focus, including treatment and outcomes, neuroimaging and additional disease-modifying factors (comorbidities, socioeconomic status, race and so on).

Multiple sclerosis in children: an update on clinical diagnosis, therapeutic strategies, and research

The clinical features, diagnostic challenges, neuroimaging appearance, therapeutic options, and pathobiological research progress in childhood-and adolescent-onset multiple sclerosis have been informed by many new insights in the past 7 years. National programmes in several countries, collaborative research efforts, and an established international paediatric multiple sclerosis study group have contributed to revised clinical diagnostic definitions, identified clinical features of multiple sclerosis that differ by age of onset, and made recommendations regarding the treatment of paediatric multiple sclerosis. The relative risks conveyed by genetic and environmental factors to paediatric multiple sclerosis have been the subject of several large cohort studies. MRI features have been characterised in terms of qualitative descriptions of lesion distribution and applicability of MRI aspects to multiple sclerosis diagnostic criteria, and quantitative studies have assessed total lesion burden and the effect of the disease on global and regional brain volume. Humoral-based and cell-based assays have identified antibodies against myelin, potassium-channel proteins, and T-cell profiles that support an adult-like T-cell repertoire and cellular reactivity against myelin in paediatric patients with multiple sclerosis. Finally, the safety and efficacy of standard first-line therapies in paediatric multiple sclerosis populations are now appreciated in more detail, and consensus views on the future conduct and feasibility of phase 3 trials for new drugs have been proposed.

JC virus antibody status in a pediatric multiple sclerosis cohort: prevalence, conversion rate and influence on disease severity

BACKGROUND

Because of the emergence of novel therapies for multiple sclerosis (MS) and the associated increased risk of progressive multifocal leukoencephalopathy, John Cunningham (JC) virus infection has become a focus of interest for neurologists. However, little is known about JC virus infection in pediatric MS to date.

OBJECTIVE

We aimed to analyze the prevalence of anti-JC virus antibodies, the conversion rate and the influence of the anti-JC virus antibody status on the clinical course in a large pediatric MS cohort.

METHODS

Anti-JC virus antibodies were analyzed in serum samples within six months of disease onset and during the course of the disease. Clinical data were extracted from a pediatric MS databank.

RESULTS

A total of 51.6% of 256 patients were found to be positive for anti-JC virus antibodies at onset of disease. No correlation between antibody status and clinical course was seen. Analyzing 693 follow-up serum samples revealed high titer stability, and an annual conversion rate of 4.37% was seen.

CONCLUSION

No evidence was found that seropositivity for anti-JC virus antibodies influences the clinical course. Surprisingly, seroprevalence for anti-JC virus antibodies was more than twice as high as anticipated in this age group, raising the question of whether the infection increases the risk of MS development.

Natalizumab treatment for multiple sclerosis: Middle East and North Africa regional recommendations for patient selection and monitoring

Background

Natalizumab, a highly specific α4-integrin antagonist, , has recently been registered across the Middle East and North Africa region. It improves clinical and magnetic resonance imaging (MRI) outcomes and reduces the rate of relapse and disability progression in relapsing-remitting multiple sclerosis (MS). Natalizumab is recommended for patients who fail first-line disease-modifying therapy or who have very active disease. Progressive multifocal leukoencephalopathy is a rare, serious adverse event associated with natalizumab.

We aim to develop regional recommendations for the selection and monitoring of MS patients to be treated with natalizumab in order to guide local neurological societies.

Methods

After a review of available literature, a group of neurologists with expertise in the management of MS met to discuss the evidence and develop regional recommendations to guide appropriate use of natalizumab in the region.

Results

Disease breakthrough is defined as either clinical (relapse or disability progression) or radiological activity (new T2 lesion or gadolinium-enhancing lesions on MRI), or a combination of both. Natalizumab is recommended as an escalation therapy in patients with breakthrough disease based on its established efficacy in Phase III studies. Several factors including prior immunosuppressant therapy, anti-John Cunningham virus (JCV) antibody status and patient choice will affect the selection of natalizumab. In highly active MS, natalizumab is considered as a first-line therapy for naive patients with disabling relapses in association with MRI activity. The anti-JCV antibody test is used to assess anti-JCV antibody status and identify the risk of PML. While seronegative patients should continue treatment with natalizumab, anti-JCV antibody testing every 6 months and annual MRI scans are recommended as part of patient monitoring. In seropositive patients, the expected benefits of natalizumab treatment have to be weighed against the risks of PML. Clinical vigilance and follow-up MRI scans remain the cornerstone of monitoring. After 2 years of natalizumab therapy, monitoring should include more frequent MRI scans (every 3–4 months) for seropositive patients, and the risk-benefit ratio should be reassessed and discussed with patients.

Conclusions

Recommendations have been developed to guide neurologists in the Middle East and North Africa on patient selection for natalizumab treatment and monitoring.

Natalizumab for multiple sclerosis: appraising risk versus benefit, a seemingly demanding tango

INTRODUCTION

Natalizumab is a highly effective monoclonal antibody used for the treatment of multiple sclerosis (MS). It reduces relapses, delays the onset of disease progression and improves disease outcomes in relapsing-remitting MS. However, treatment with natalizumab is associated with progressive multifocal leukoencephalopathy (PML), a severe opportunistic brain infection with John Cunningham virus.

AREAS COVERED

In this review, we discuss the mechanism of action, results of pivotal studies, clinical use and adverse effects associated with natalizumab therapy with emphasis on PML. A risk stratification strategy to optimize natalizumab therapy is included. This review also summarizes the alternative and upcoming therapies available for the treatment of MS.

EXPERT OPINION

Natalizumab is a very effective therapy for MS and has shown tremendous results in reducing the disease activity and improving patients' quality of life. Serious adverse effect such as PML warrant extreme caution and heightened clinical vigilance while prescribing the drug. If used with prudence, the drug can be instrumental in treatment of patients with inadequate response to the first-line medications.

Best practice in the use of natalizumab in multiple sclerosis

Natalizumab is approved for the treatment of patients with relapsing-remitting multiple sclerosis who have failed first-line treatment with traditional disease-modifying therapies or who have highly active disease. The drug has proved highly effective, both in a clinical trial setting and in clinical practice, with marked reductions in the rate of clinical relapses and slowed disease progression. These clinical outcomes are mirrored by a marked reduction in disease activity as evidenced by magnetic resonance imaging of the brain. However, natalizumab treatment has been associated with a risk of progressive multifocal leukoencephalopathy (PML), a potentially fatal condition caused by JC virus (JCV) activation. When this condition was detected in a clinical trial shortly after approval, the drug was immediately and voluntarily withdrawn from the market. As a condition of its reinstatement, stringent pharmacovigilance measures and a risk management plan were enforced. The recent availability of a two-step enzyme-linked immunosorbent assay (ELISA) test for the presence of anti-JCV antibodies (free testing is available in a central laboratory for registered centers), along with an ever-improving understanding of other risk factors such as prior immunosuppressant use and duration of treatment, allow an increasingly refined stratification of the risk of PML. This improved stratification of risk can help guide decisions about treatment. This review will also deal with other topics of relevance to clinical practice such as the development of antinatalizumab antibodies and their negative implications in terms of hypersensitivity reactions and loss of efficacy, withdrawal of treatment, and compassionate pediatric use.

Natalizumab in pediatric multiple sclerosis: results of a cohort of 55 cases

BACKGROUND

Limited information is available on the use of natalizumab (NA) in pediatric multiple sclerosis (ped-MS) patients.

OBJECTIVE

The purpose of this study was to describe the long-term effects of NA in a large cohort of active ped-MS patients.

METHODS

Patients with definite ped-MS were treated with NA if in the previous year they had experienced at least two relapses or a severe relapse with incomplete recovery while on immunomodulating treatment, or at least two relapses and new magnetic resonance imaging (MRI) lesions regardless of any prior treatment.

RESULTS

The study included 55 patients (mean age: 14.4 years, mean number of relapses: 4.4, pre-treatment mean disease duration: 25.5 months). They received a median number of 26 infusions. Three relapses occurred during the follow-up, one female patient continued to deteriorate in cognitive functioning. Mean Expanded Disability Status Scale (EDSS) scores decreased from 2.7 to 1.9 at the last visit (p<0.001). During the follow-up the majority of patients remained free from MRI activity. Transient and mild clinical adverse events occurred in 20 patients. Mild hematological abnormalities occurred in seven patients. Anti-JCV antibodies were detected in 20/51 tested patients.

CONCLUSIONS

NA was well tolerated in all patients. A strong suppression of disease activity was observed in the majority of patients during the follow-up.

Natalizumab use in pediatric patients with relapsing-remitting multiple sclerosis

BACKGROUND

Not all pediatric patients with relapsing-remitting multiple sclerosis (MS) may respond to traditional disease-modifying therapies. Natalizumab has been shown to be effective but is currently only approved in adults.

OBJECTIVE

To analyze the safety and efficacy of natalizumab in patients under 18 years of age diagnosed with MS.

METHOD

Data for pediatric patients with MS treated with natalizumab in a compassionate use setting were retrospectively collected and analyzed.

RESULTS

Valid data were obtained for nine patients under 18 years from seven different centers (mean age, 15 years 4 months [range 9.8-17.7]; 5 were boys). Patients received a median of 17 infusions of natalizumab (range, 2-31) and eight received at least 12 infusions. For these 8 patients, the median score on the Expanded Disability Status Scale decreased from 3.0 to 1.0 and the median annualized relapse rate decreased from 3.0 to 0. After 12 months, no patients reported gadolinium-enhancing lesions compared to seven at baseline. Four post-baseline adverse events occurred and one patient discontinued due to hypersensitivity reaction.

CONCLUSION

Natalizumab is a highly effective treatment as a second-line option in pediatric patients. In as far as the limited numbers allowed comparisons, the safety and efficacy of natalizumab in children was in line with the experience published in adult populations.

The management of pediatric multiple sclerosis

Prevention of disability through disease-modifying therapies has been a source of significant attention among clinicians treating children and adolescents with multiple sclerosis (MS). In this article, we will review currently available literature on therapies and the management of pediatric-onset multiple sclerosis, with specific discussion of therapies for acute exacerbations and disease-modifying therapies that may prevent relapses and slow disease progression, and will include a brief discussion of future directions in symptomatic interventions for cognitive decline, fatigue, and depression in children and adolescents with multiple sclerosis. Our article will focus specifically on children and adolescents with relapsing-remitting multiple sclerosis, as 99% of cases of pediatric-onset multiple sclerosis are relapsing-remitting multiple sclerosis.

Treating multiple sclerosis with natalizumab

Natalizumab is the first monoclonal antibody approved for the treatment of relapsing multiple sclerosis. Pivotal trials demonstrated the efficacy of natalizumab on clinical and paraclinical measures of disease activity and disability progression. Although a direct comparison has not been performed yet, natalizumab seems to be more efficacious than the currently available immunomodulant drugs, such as IFN-β and glatiramer acetate. Despite its efficacy, the occurrence of an increased risk of progressive multifocal leukoencephalopathy with the treatment, raises concerns about its widespread use in multiple sclerosis patients. This paper provides an overview of the most relevant results from the Phase I-IV studies on natalizumab and highlights the challenges addressed to minimize and manage its adverse events in clinical practice.

Current therapeutic options in pediatric multiple sclerosis

OPINION STATEMENT

Therapies for relapsing-remitting pediatric multiple sclerosis (MS) are aimed at preventing relapses (disease modifying therapies), treating acute attacks, and managing disabling cognitive and physical symptoms. Initial disease modifying therapy to prevent relapses should use one of four first-line injectable therapies that are approved for adult relapsing-remitting MS: interferon beta 1a IM, interferon beta 1a SC, interferon beta 1b SC, or glatiramer acetate. If breakthrough disease occurs or the medication is poorly tolerated, the next step should be to try one of the other first-line therapies. If the first-line therapies have been exhausted, second-line therapies such as natalizumab, cyclophosphamide, or mitoxantrone may be considered. One must use caution when choosing these potent therapies, as secondary effects may include serious infection or malignancy. Phase III studies in adult MS have been published on two oral agents, fingolimod and cladribine, and fingolimod has received FDA approval for use in relapsing-remitting MS in adults. These drugs have not been evaluated in the pediatric MS population, nor have any of three other oral agents now in phase III development: laquinimod, BG-12, and teriflunomide. Acute relapses can be treated with pulse methylprednisolone at a dosage of 20 to 30 mg/kg per day (maximum 1 g per day) for 3 to 5 days. If this is ineffective, intravenous immunoglobulin (2 g/kg divided over 2-5 days) or plasmapheresis may be considered. Neuropsychological, physical therapy, and occupational therapy screening should be performed on patients with pediatric MS. Interventions focusing on visual motor integration may be particularly useful in this group Spasticity may be treated with symptomatic therapies, but one must be aware of potential adverse effects of agents such as baclofen and diazepam. Headache, fatigue, anxiety, and depression are frequently seen, and patients may need a psychiatry consultation and counseling.