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

Old and New Strategies in the Treatment of Pediatric Multiple Sclerosis: A Personal View for a New Treatment Approach

Up to 10 years ago the most common approach to the treatment of pediatric MS (ped-MS) was to start with IFNB or GA (so-called first-line therapies or moderate-efficacy disease-modifying therapies [ME-DMTs]) and to switch to more aggressive treatments (or high-efficacy disease-modifying therapies [HE-DMTs]) in non-responder patients. The use of HE-DMTs as first choice was recommended in selected cases with an active, aggressive form of MS. Indications for the treatment of ped-MS were essentially derived from data of observational studies. Recently, results of three randomized clinical trials have been published as well as data from many observational studies evaluating the effect of new and more active DMTs, with clear evidence that HE-DMTs are more effective than ME-DMTs. Therefore, the paradigm of treatment for patients with MS onset before 18 years of age should be changed, offering treatment with HE-DMTs as first option, because of their superior effectiveness to prevent relapses and disease progression. HE-DMTs present an overall reassuring safety profile and obtain better adherence to treatment.

Comparative Effectiveness of Natalizumab, Fingolimod, and Injectable Therapies in Pediatric-Onset Multiple Sclerosis: A Registry-Based Study

BACKGROUND AND OBJECTIVES

Patients with pediatric-onset multiple sclerosis (POMS) typically experience higher levels of inflammation with more frequent relapses, and though patients with POMS usually recover from relapses better than adults, patients with POMS reach irreversible disability at a younger age than adult-onset patients. There have been few randomized, placebo-controlled clinical trials of multiple sclerosis (MS) disease-modifying therapies (DMTs) in patients with POMS, and most available data are based on observational studies of off-label use of DMTs approved for adults. We assessed the effectiveness of natalizumab compared with fingolimod using injectable platform therapies as a reference in pediatric patients in the global MSBase registry.

METHODS

This retrospective study included patients with POMS who initiated treatment with an injectable DMT, natalizumab, or fingolimod between January 1, 2006, and May 3, 2021. Patients were matched using inverse probability treatment weighting. The primary outcome was time to first relapse from index therapy initiation. Secondary study outcomes included annualized relapse rate; proportions of relapse-free patients at 1, 2, and 5 years; time to treatment discontinuation; and times to 24-week confirmed disability worsening and confirmed disability improvement.

RESULTS

A total of 1,218 patients with POMS were included in this analysis. Patients treated with fingolimod had a significantly lower risk of relapse than patients treated with injectable DMTs (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.29-0.83; p = 0.008). After adjustment for prior DMT experience in the unmatched sample, patients treated with natalizumab had a significantly lower risk of relapse than patients treated either with injectable DMTs (HR, 0.15; 95% CI 0.07-0.31; p < 0.001) or fingolimod (HR, 0.37; 95% CI 0.14-1.00; p = 0.049). The adjusted secondary study outcomes were generally consistent with the primary outcome or with previous observations. The findings in the inverse probability treatment weighting-adjusted patient populations were confirmed in multiple sensitivity analyses.

DISCUSSION

Our analyses of relapse risk suggest that natalizumab is more effective than fingolimod in the control of relapses in this population with high rates of new inflammatory activity, consistent with previous studies of natalizumab and fingolimod in adult-onset patients and POMS. In addition, both fingolimod and natalizumab were more effective than first-line injectable therapies.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that patients with POMS treated with natalizumab had a lower risk of relapse than those with fingolimod.

Clinical predictors of NEDA-3 one year after diagnosis of pediatric multiple sclerosis: an exploratory single-center study

Introduction

Multiple sclerosis (MS) is an inflammatory and demyelinating disorder of central nervous system that can be diagnosed in pediatric age (<18 years) in 3-5% of the cases. This early onset is associated with higher relapse rates and earlier progression to neurological disability. By using NEDA-3 (No Evidence of Disease Activity-3) criteria, we aimed to identify clinical predictors associated with absence of disease activity and control of disease progression 12 months after the diagnosis, in a cohort of pediatric-onset MS (POMS) patients regularly followed-up in our center.

Methods

We analyzed demographic, clinical, laboratorial and imaging variables of patients with POMS identified in our center, between 2010 and 2021, in two moments: at the diagnosis and 12 months after it. Statistical tests were applied to compare the distribution of those variables between groups defined by NEDA-3 status and by each one of its three variable components.

Results

We included 27 patients in the study (18 female), with a mean age of 14.8 years (± 2.8), being all diagnosed with relapsing-remitting MS and with a median score of 1.5 at the Expanded Disability Status Scale (EDSS). The use of natalizumab (p = 0.017) and the negativity for anti-EBV IgG antibodies (p = 0.018) at diagnosis were associated with a higher achievement of NEDA-3 status 12 months after, in our cohort. Prescribed treatment was also associated with statistically significant differences in the "absence of MRI activity" component of NEDA-3 (p = 0.006): patients under treatment with natalizumab had a higher probability of achieving this status, and the opposite was observed in glatiramer acetate-treated children.

Discussion and conclusion

Our exploratory results underline the pivotal importance that an early and more effective therapeutical approach may have in the control of disease activity, in POMS. Additionally, they also seem to suggest that the presence of anti-EBV antibodies is not innocent, as it can be related to a less favorable evolution of the disease, even at a very early stage. Further studies are needed to confirm the applicability of these variables as prognostic and personalized tools in this clinical setting.

Long-term follow-up (up to 11 years) of an Italian pediatric MS cohort treated with Natalizumab: a multicenter, observational study

BACKGROUND

Natalizumab (NAT) has a strong impact on disease activity of aggressive pediatric multiple sclerosis (MS), with no difference in safety profile compared to adult MS. However, available data are limited by short follow-up. Our aim was to report long-term follow-up data (up to 11 years) of a large Italian pediatric MS cohort treated with NAT.

MATERIALS AND METHODS

We retrospectively collected data of pediatric MS patients treated with NAT included in a previous study and prospectively followed in Italian MS centers. We compared disease activity pre, during, and post-NAT and we performed survival analyses of time to evidence of disease activity (EDA) during NAT, time to reach EDA post-NAT, and time to NAT discontinuation.

RESULTS

Ninety-two patients were included from 19 MS centers in Italy. At NAT initiation, cohort's characteristics were as follows: 55 females; 14.7 ± 2.4 (mean ± SD) years of age; 34 naïve to disease modifying therapies; 1-year pre-NAT annualized relapse rate (ARR): 2.2 ± 1.2; EDSS (median [IQR]): 2.5 [2.0-3.0]; gadolinium-enhancing lesions: 2 [1-5]; 41 JCV positives. During NAT treatment (61.9 ± 35.2 mean infusions), ARR lowered to 0.08 ± 0.23 (p < 0.001), EDSS score to 1.5 [1.0-2.5] at last infusion (p < 0.001), and 51% patients had EDA (21% after 6 months of rebaseline). No serious adverse events were reported. Forty-nine patients discontinued NAT, mainly due to PML concern; the majority (29/49) had disease reactivation in the subsequent 12 months, of which three with a clinical rebound.

CONCLUSION

NAT treatment maintains its high efficacy for a long time in pediatric MS patients, with no new safety issues.

Natalizumab therapy in patients with pediatric-onset multiple sclerosis in Greece: clinical and immunological insights of time-long administration and future directions-a single-center retrospective observational study

Pediatric-onset multiple sclerosis (MS, POMS) accounts for 3-5% of all MS cases and is characterized by a highly inflammatory profile, often warranting treatment with high-efficacy agents. Our aim is to present real-world data of a series of 18 Hellenic POMS patients treated with natalizumab (NTZ) either as adolescents or as adults, after high disease activity has efficiently subsided. Clinical and imaging/laboratory data from 18 POMS patients who have received at least one NTZ infusion were selected in this single-center retrospective observational study. Human leukocyte antigen (HLA) genotyping was performed with standard low-resolution sequence-specific oligonucleotide techniques. Eighteen patients with a mean age of disease onset of 15.3 ± 2.4 years were treated with NTZ with a mean of 51.7 ± 46.4 infusions, 6 as adolescents and 12 as adults. 22.2% were treatment naïve. At the end of the observational period, patients of both groups remained relapse-free, with no radiological activity and significantly reduced disability accumulation. No evidence of disease activity (NEDA)-3 status was achieved in 66.7% of all patients, 58.3% in the adult-treated, and 83.3% in the adolescent-treated POMS patients. NTZ was generally well tolerated. Only 5 adverse events were observed, in 3 patients who were carriers of the HLA-DRB1*15 (HLA-DRB1*15/HLA-DRB1*11 and HLA-DRB1*15/HLA-DRB1*13 genotypes), 1 homozygous for the HLA-DRB1*03 allele and 1 heterozygous for HLA-DRB1*04 and HLA-DRB1*16 alleles. NTZ is highly efficacious and mostly safe for POMS patients with high disease activity in all age groups. The role of immunogenetics in personalized patient evaluation and treatment needs to be further investigated.

Treatment of multiple sclerosis in children: A brief overview

Multiple sclerosis (MS) is the most common autoimmune, chronic inflammatory demyelinating disorder of the central nervous system. Pediatric-onset MS (POMS), as opposed to adult-onset MS (AOMS), is a rare condition, presenting similar clinical features to AOMS, but a more active course of the disease, with higher relapse rates and greater white and grey matter damage. To date, the therapeutic approaches to treat POMS have been extrapolated from observational studies and data from trials conducted on adults, raising concerns about their efficacy and safety in the pediatric population. Herein, we discuss the most common therapeutic strategies used in POMS management, basing on the individual clinical practice and experience.

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.