Observatoire Français de la Sclérose en Plaques (OFSEP): A unique multimodal nationwide MS registry in France

Anti-CD20 Therapies in Drug-Naive Patients With Primary Progressive Multiple Sclerosis: A Multicenter Real-Life Study

BACKGROUND AND OBJECTIVES

Although rituximab failed to demonstrate a significant effect on disability progression in primary progressive multiple sclerosis (PPMS), ocrelizumab succeeded. Our main objective was to analyze confirmed disability progression (CDP) in a cohort of patients with PPMS treated with anti-CD20 therapies compared with a weighted untreated control cohort.

METHODS

This was a retrospective study using data from the French MS registry (Observatoire Français de la Sclérose En Plaques). We included patients with PPMS treated or never treated with anti-CD20 therapies from 2016 to 2021, with an Expanded Disability Status Scale score of ≤6.5 at baseline. The primary outcome was time to first CDP. The secondary outcomes were time to first relapse, MRI activity at 2 years, identification of risk factors associated with CDP, and serious infection incidence rates (IIRs). Each outcome was studied using an inverse probability of treatment weighting method. The outcomes were modeled using a weighted proportional Cox model for the time-to-event outcomes and by a logistic regression regarding the MRI activity.

RESULTS

A total of 1,184 patients (426 treated and 758 untreated) fulfilled the inclusion criteria. Median age (Q1-Q3) was 56 years (49.3-63.8), and 52.7% were female. Among treated patients, 295 received rituximab, whereas 131 received ocrelizumab. At baseline, anti-CD20-treated patients were younger (median 51.9 vs 58.6 years, Cohen d = 0.683) and had more active disease (54.5 vs 27.8%, Cohen d = 0.562). 91.6% were drug-naive at inclusion. In time to first CDP analysis, no statistical significance was observed (hazard ratio [HR], 1.13; 95% CI 0.93-1.36, p = 0.2113). In time to first relapse analysis, a nonsignificant trend toward fewer patients relapsing in the treated group was observed (HR 0.83; 95% CI 0.48-1.28, p = 0.0809). For MRI activity, no significant difference was found between the 2 groups. Risk factors associated with CDP in the treated group were male sex and MS duration. IIR was 6.67 (95% CI 3.12-14.25) per 100 person-years in the treated group vs 2.67 (95% CI 0.80-8.86) in the untreated group.

DISCUSSION

Time to first CDP was not different between anti-CD20 treated and untreated patients with PPMS. Although our study is retrospective and mainly included patients treated by rituximab, our results indicate that there should be a constant evaluation of all available data to ascertain the best risk/benefit ratio for patients with PPMS.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that anti-CD20 therapy of previously untreated patients with PPMS was not superior to no therapy in delaying time to first CDP.

Serum NfL and GFAP are weak predictors of long-term multiple sclerosis prognosis: A 6-year follow-up

BACKGROUND

Serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) are promising biomarkers that might be associated with clinical and radiological markers of multiple sclerosis (MS) severity. However, it is not known whether they can accurately identify patients at risk of disability progression in the medium and long term.

OBJECTIVES

We wanted to determine the association between sNfL and sGFAP, Expanded Disability Status Scale score changes, and conversion to secondary progressive MS (SPMS) in a cohort of 133 patients with relapsing remitting MS.

METHODS

Blood samples were collected at inclusion to measure SNfL and sGFAP by single molecule array and their prognostic value was assessed using a linear mixed model.

RESULTS

In this cohort, 37 patients (27.8 % of 133) experienced disability progression and 12 patients (9.0 %) converted to SPMS during the follow-up (mean follow-up duration: 6.4 years). Only sNfL (p = 0.03) was associated with conversion to SPMS, and neither SNfL nor sGFAP was associated with disability progression.

CONCLUSION

Serum NfL and GFAP do not seem to accurately predict MS outcome in the long term. More studies are needed to determine how serum biomarkers, associated with other clinical and MRI biomarkers, might be used to improve MS prognostication.

Acute Clinical Events Identified as Relapses With Stable Magnetic Resonance Imaging in Multiple Sclerosis

Importance

Understanding the association between clinically defined relapses and radiological activity in multiple sclerosis (MS) is essential for patient treatment and therapeutic development.

Objective

To investigate clinical events identified as relapses but not associated with new T2 lesions or gadolinium-enhanced T1 lesions on brain and spinal cord magnetic resonance imaging (MRI).

Design, Setting, and Participants

This multicenter observational cohort study was conducted between January 2015 and June 2023. Data were extracted on June 8, 2023, from the French MS registry. All clinical events reported as relapses in patients with relapsing-remitting MS were included if brain and spinal cord MRI was performed within 12 and 24 months before the event, respectively, and 50 days thereafter with gadolinium injection.

Exposures

Events were classified as relapses with active MRI (RAM) if a new T2 lesion or gadolinium-enhanced T1 lesion appeared on brain or spinal cord MRI or as acute clinical events with stable MRI (ACES) otherwise.

Main Outcomes and Measures

Factors associated with ACES were investigated; patients with ACES and RAM were compared regarding Expanded Disability Status Scale (EDSS) course, relapse rate, confirmed disability accrual (CDA), relapse-associated worsening (RAW), progression independent of relapse activity (PIRA), and transition to secondary progressive (SP) MS, and ACES and RAM rates under each disease-modifying therapy (DMT) were estimated.

Results

Among 31 885 clinical events, 637 in 608 patients (493 [77.4%] female; mean [SD] age, 35.8 [10.7] years) were included. ACES accounted for 166 (26.1%) events and were more likely in patients receiving highly effective DMTs, those with longer disease duration (odds ratio [OR], 1.04; 95% CI, 1.01-1.07), or those presenting with fatigue (OR, 2.14; 95% CI, 1.15-3.96). ACES were associated with significant EDSS score increases, lower than those found for RAM. Before the index event, patients with ACES experienced significantly higher rates of relapse (relative rate [RR], 1.21; 95% CI, 1.01-1.46), CDA (hazard ratio [HR], 1.54; 95% CI, 1.13-2.11), and RAW (HR, 1.72; 95% CI, 1.20-2.45). Patients with ACES were at significantly greater risk of SP transition (HR, 2.58; 95% CI, 1.02-6.51). Although RAM rate decreased with DMTs according to their expected efficacy, ACES rate was stable across DMTs.

Conclusions and Relevance

The findings in this study introduce the concept of ACES in MS, which accounted for one-fourth of clinical events identified as relapses.

Framework for personalized prediction of treatment response in relapsing-remitting multiple sclerosis: a replication study in independent data

BACKGROUND

Individualizing and optimizing treatment of relapsing-remitting multiple sclerosis patients is a challenging problem, which would benefit from a clinically valid decision support. Stühler et al. presented black box models for this aim which were developed and internally evaluated in a German registry but lacked external validation.

METHODS

In patients from the French OFSEP registry, we independently built and validated models predicting being free of relapse and free of confirmed disability progression (CDP), following the methodological roadmap and predictors reported by Stühler. Hierarchical Bayesian models were fit to predict the outcomes under 6 disease-modifying treatments given the individual disease course up to the moment of treatment change. Data was temporally split on 2017, and models were developed in patients treated earlier (n = 5517). Calibration curves, discrimination, mean squared error (MSE) and relative percentage of root MSE (RMSE%) were assessed by external validation of models in more-recent patients (n = 3768). Non-Bayesian fixed-effects GLMs were also applied and their outcomes were compared to these of the Bayesian ones. For both, we modelled the number of on-therapy relapses with a negative binomial distribution, and CDP occurrence with a binomial distribution.

RESULTS

The performance of our temporally-validated relapse model (MSE: 0.326, C-Index: 0.639) is potentially superior to that of Stühler's (MSE: 0.784, C-index: 0.608). Calibration plots revealed miscalibration. Our CDP model (MSE: 0.072, C-Index: 0.777) was also better than its counterpart (MSE: 0.131, C-index: 0.554). Results from non-Bayesian fixed-effects GLM models were similar to the Bayesian ones.

CONCLUSIONS

The relapse and CDP models rebuilt and externally validated in independent data could compare and strengthen the credibility of the Stühler models. Their model-building strategy was replicable.

Narrative Review on the Use of Cladribine Tablets as Exit Therapy for Stable Elderly Patients with Multiple Sclerosis

The number of ageing people with relapsing multiple sclerosis (RMS) is increasing. The efficacy of disease-modifying therapies (DMTs) for RMS declines with age. Also, older persons with MS may be more susceptible to infections, hospitalisations and malignancy. Aging people with MS have higher rates of comorbidities versus aged-matched controls, increasing the individual risk of disability. We review the therapeutic properties of cladribine tablets (CladT) in ageing people with RMS, with regard to their utility for allowing these individuals to cease continuous administration of a DMT (i.e. to act as an "exit therapy"). CladT is thought to be an immune reconstitution therapy, in that two short courses of oral treatment 1 year apart provide suppression of MS disease activity in responders that far outlasts the duration of treatment and post-treatment reductions in lymphocyte counts. Post hoc analyses, long-term follow-up of populations with RMS in randomised trials, and real-world evidence suggest that the efficacy of CladT is probably independent of age, although more data in the elderly are still needed. No clear adverse signals for lymphopenia or other adverse safety signals have emerged with increasing age, although immunosenescence in the setting of age-related "inflammaging" may predispose elderly patients to a higher risk of infections. Updating vaccination status is recommended, especially against pneumococci and herpes zoster for older patients, to minimise the risk of these infections. CladT may be a useful alternative treatment for ageing people with MS who often bear a burden of multiple comorbidities and polypharmacy and who are more exposed to the adverse effects of continuous immunosuppressive therapy.

Big Multiple Sclerosis Data network: an international registry research network

BACKGROUND

The Big Multiple Sclerosis Data (BMSD) network ( https://bigmsdata.org ) was initiated in 2014 and includes the national multiple sclerosis (MS) registries of the Czech Republic, Denmark, France, Italy, and Sweden as well as the international MSBase registry. BMSD has addressed the ethical, legal, technical, and governance-related challenges for data sharing and so far, published three scientific papers on pooled datasets as proof of concept for its collaborative design.

DATA COLLECTION

Although BMSD registries operate independently on different platforms, similarities in variables, definitions and data structure allow joint analysis of data. Certain coordinated modifications in how the registries collect adverse event data have been implemented after BMSD consensus decisions, showing the ability to develop together.

DATA MANAGEMENT

Scientific projects can be proposed by external sponsors via the coordinating centre and each registry decides independently on participation, respecting its governance structure. Research datasets are established in a project-to-project fashion and a project-specific data model is developed, based on a unifying core data model. To overcome challenges in data sharing, BMSD has developed procedures for federated data analysis.

FUTURE PERSPECTIVES

Presently, BMSD is seeking a qualification opinion from the European Medicines Agency (EMA) to conduct post-authorization safety studies (PASS) and aims to pursue a qualification opinion also for post-authorization effectiveness studies (PAES). BMSD aspires to promote the advancement of real-world evidence research in the MS field.

Vulnerability of Thalamic Nuclei at CSF Interface During the Entire Course of Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Thalamic atrophy can be used as a proxy for neurodegeneration in multiple sclerosis (MS). Some data point toward thalamic nuclei that could be affected more than others. However, the dynamic of their changes during MS evolution and the mechanisms driving their differential alterations are still uncertain.

METHODS

We paired a large cohort of 1,123 patients with MS with the same number of healthy controls, all scanned with conventional 3D-T1 MRI. To highlight the main atrophic regions at the thalamic nuclei level, we validated a segmentation strategy consisting of deep learning-based synthesis of sequences, which were used for automatic multiatlas segmentation. Then, through a lifespan-based approach, we could model the dynamics of the 4 main thalamic nuclei groups.

RESULTS

All analyses converged toward a higher rate of atrophy for the posterior and medial groups compared with the anterior and lateral groups. We also demonstrated that focal MS white matter lesions were associated with atrophy of groups of nuclei when specifically located within the associated thalamocortical projections. The volumes of the most affected posterior group, but also of the anterior group, were better associated with clinical disability than the volume of the whole thalamus.

DISCUSSION

These findings point toward the thalamic nuclei adjacent to the third ventricle as more susceptible to neurodegeneration during the entire course of MS through potentiation of disconnection effects by regional factors. Because this information can be obtained even from standard T1-weighted MRI, this paves the way toward such an approach for future monitoring of patients with MS.

High-Efficacy Therapy Discontinuation vs Continuation in Patients 50 Years and Older With Nonactive MS

Importance

A recent randomized clinical trial concluded that discontinuing medium-efficacy therapy might be a reasonable option for older patients with nonactive multiple sclerosis (MS), but there is a lack of data on discontinuing high-efficacy therapy (HET). In younger patients, the discontinuation of natalizumab and fingolimod is associated with a risk of rebound of disease activity.

Objective

To determine whether discontinuing HET in patients 50 years and older with nonactive MS is associated with an increased risk of relapse compared with continuing HET.

Design, Setting, and Participants

This observational cohort study used data from 38 referral centers from the French MS registry (Observatoire Français de la Sclérose en Plaques [OFSEP] database). Among 84704 patients in the database, data were extracted for 1857 patients 50 years and older with relapsing-remitting MS treated by HET and with no relapse or magnetic resonance imaging activity for at least 2 years. After verification of the medical records, 1620 patients were classified as having discontinued HET or having remained taking treatment and were matched 1:1 using a dynamic propensity score (including age, sex, disease phenotype, disability, treatment of interest, and time since last inflammatory activity). Patients were included from February 2008 to November 2021, with a mean (SD) follow-up of 5.1 (2.9) years. Data were extracted in June 2022.

Exposures

Natalizumab, fingolimod, rituximab, and ocrelizumab.

Main Outcomes and Measures

Time to first relapse.

Results

Of 1620 included patients, 1175 (72.5%) were female, and the mean (SD) age was 54.7 (4.8) years. Among the 1452 in the HET continuation group and 168 in the HET discontinuation group, 154 patients in each group were matched using propensity scores (mean [SD] age, 57.7 [5.5] years; mean [SD] delay since the last inflammatory activity, 5.6 [3.8] years; mean [SD] follow-up duration after propensity score matching, 2.5 [2.1] years). Time to first relapse was significantly reduced in the HET discontinuation group compared with the HET continuation group (hazard ratio, 4.1; 95% CI, 2.0-8.5; P < .001) but differed between HETs, with a hazard ratio of 7.2 (95% CI, 2.1-24.5; P = .001) for natalizumab, 4.5 (95% CI, 1.3-15.5; P = .02) for fingolimod, and 1.1 (95% CI, 0.3-4.8; P = .85) for anti-CD20 therapy.

Conclusion and Relevance

As in younger patients, in patients 50 years and older with nonactive MS, the risk of relapse increased significantly after stopping HETs that impact immune cell trafficking (natalizumab and fingolimod). There was no significant increase in risk after stopping HETs that deplete B-cells (anti-CD20 therapy). This result may inform decisions about stopping HETs in clinical practice.

Highly Effective Therapies as First-Line Treatment for Pediatric-Onset Multiple Sclerosis

Importance

Moderately effective therapies (METs) have been the main treatment in pediatric-onset multiple sclerosis (POMS) for years. Despite the expanding use of highly effective therapies (HETs), treatment strategies for POMS still lack consensus.

Objective

To assess the real-world association of HET as an index treatment compared with MET with disease activity.

Design, Setting, and Participants

This was a retrospective cohort study conducted from January 1, 2010, to December 8, 2022, until the last recorded visit. The median follow-up was 5.8 years. A total of 36 French MS centers participated in the Observatoire Français de la Sclérose en Plaques (OFSEP) cohort. Of the total participants in OFSEP, only treatment-naive children with relapsing-remitting POMS who received a first HET or MET before adulthood and at least 1 follow-up clinical visit were included in the study. All eligible participants were included in the study, and none declined to participate.

Exposure

HET or MET at treatment initiation.

Main Outcomes and Measures

The primary outcome was the time to first relapse after treatment. Secondary outcomes were annualized relapse rate (ARR), magnetic resonance imaging (MRI) activity, time to Expanded Disability Status Scale (EDSS) progression, tertiary education attainment, and treatment safety/tolerability. An adapted statistical method was used to model the logarithm of event rate by penalized splines of time, allowing adjustment for effects of covariates that is sensitive to nonlinearity and interactions.

Results

Of the 3841 children (5.2% of 74 367 total participants in OFSEP), 530 patients (mean [SD] age, 16.0 [1.8] years; 364 female [68.7%]) were included in the study. In study patients, both treatment strategies were associated with a reduced risk of first relapse within the first 2 years. HET dampened disease activity with a 54% reduction in first relapse risk (adjusted hazard ratio [HR], 0.46; 95% CI, 0.31-0.67; P < .001) sustained over 5 years, confirmed on MRI activity (adjusted odds ratio [OR], 0.34; 95% CI, 0.18-0.66; P = .001), and with a better tolerability pattern than MET. The risk of discontinuation at 2 years was 6 times higher with MET (HR, 5.97; 95% CI, 2.92-12.20). The primary reasons for treatment discontinuation were lack of efficacy and intolerance. Index treatment was not associated with EDSS progression or tertiary education attainment (adjusted OR, 0.51; 95% CI, 0.24-1.10; P = .09).

Conclusions and Relevance

Results of this cohort study suggest that compared with MET, initial HET in POMS was associated with a reduction in the risk of first relapse with an optimal outcome within the first 2 years and was associated with a lower rate of treatment switching and a better midterm tolerance in children. These findings suggest prioritizing initial HET in POMS, although long-term safety studies are needed.

The Response Study: A French registry on pregnancy in women with MS and related disorders and their children up to 6 years-Protocol, recruitment status, and baseline characteristics

BACKGROUND

Counseling on pregnancy is still challenging, particularly regarding the use of disease-modifying treatments (DMTs). We are lacking long-term outcomes in children exposed to DMTs.

OBJECTIVES

This study aimed to set up a French pregnancy registry for women with multiple sclerosis (MS) and related disorders nested within the Observatoire Français de la Sclérose en Plaques (OFSEP) cohort.

METHODS

Prospective, observational, multicentric, epidemiological study in France. Neurological visits are organized according to routine practice. Data are collected on the OFSEP minimal datasheet. Auto-questionnaires on pregnancy are completed by patients at Months 5-6 and 8 during pregnancy, and Months 3, 6, and 12 postpartum. A specific survey on analgesia is completed by anesthesiologists. Pediatric data are collected from the child's health book, where visits on Day 8, Month 9, and 24 are mandatory. Parents complete neurodevelopmental questionnaires at Year 1, Years 2 and 6.

RESULTS

The RESPONSE study started in August 2019. On 7 April 2023, 515 women were included. Baseline demographics are presented.

CONCLUSIONS

RESPONSE will provide rich information on the global management of pregnancy in France and prospective data on children until the age of 6 years, exposed or not to a DMT, including data on neurodevelopment that can be compared to the general population.

STUDY FUNDING

EDMUS and ARSEP Foundation, Biogen, Roche.

Real-life study to assess effectiveness and safety of eculizumab in patients with neuromyelitis optica spectrum disorders in France: protocol for ECUP4, an observational study

Background

Eculizumab, a humanized monoclonal antibody targeting the C5 complement protein, has been approved for the treatment of neuromyelitis optica spectrum disorders (NMOSD) in adult patients who are anti-aquaporin-4 (AQP4) antibody positive (Ab+). The aim of this study is to evaluate the long-term effectiveness and safety of eculizumab in French adults with NMOSD and to describe patients' characteristics, disability, and quality of life using data collected in a real-world setting.

Methods

This is the protocol for ECUP4, an ongoing prospective, observational, non-comparative, multicenter study conducted in 32 reference centers in France. Eligible patients must also be enrolled in NOMADMUS, a nested cohort of the French national multiple sclerosis registry (OFSEP). The primary endpoint is the annualized relapse rate. Secondary endpoints include the long-term safety of eculizumab, as well as patients' characteristics, treatment outcomes, disability, pain, visual acuity, and quality of life. Visits and treatments follow routine clinical practice. The case report forms (CRF) comprise data recorded in the context of the NOMADMUS cohort, collected during routine visits. The inclusion period is planned for 3 years, with no limitation on the number of patients enrolled. The maximum follow-up duration will be 5.5 years.

Conclusion

The efficacy and safety of eculizumab in patients with AQP4+ NMOSD have been demonstrated in randomized clinical trials that showed a significant reduction in the risk of relapse, with a safety profile consistent with other indications. This study will provide clinical and patient-reported evidence of the benefits of eculizumab, using data from a real-world setting in France.

Trial registration number

This study is registered at the French public repertory Health data Hub, N° F20211228123801. All information can be accessed at: https://www.health-data-hub.fr/.

Brain structure ages-A new biomarker for multi-disease classification

Age is an important variable to describe the expected brain's anatomy status across the normal aging trajectory. The deviation from that normative aging trajectory may provide some insights into neurological diseases. In neuroimaging, predicted brain age is widely used to analyze different diseases. However, using only the brain age gap information (i.e., the difference between the chronological age and the estimated age) can be not enough informative for disease classification problems. In this paper, we propose to extend the notion of global brain age by estimating brain structure ages using structural magnetic resonance imaging. To this end, an ensemble of deep learning models is first used to estimate a 3D aging map (i.e., voxel-wise age estimation). Then, a 3D segmentation mask is used to obtain the final brain structure ages. This biomarker can be used in several situations. First, it enables to accurately estimate the brain age for the purpose of anomaly detection at the population level. In this situation, our approach outperforms several state-of-the-art methods. Second, brain structure ages can be used to compute the deviation from the normal aging process of each brain structure. This feature can be used in a multi-disease classification task for an accurate differential diagnosis at the subject level. Finally, the brain structure age deviations of individuals can be visualized, providing some insights about brain abnormality and helping clinicians in real medical contexts.

Predictors of treatment switching in the Big Multiple Sclerosis Data Network

Background

Treatment switching is a common challenge and opportunity in real-world clinical practice. Increasing diversity in disease-modifying treatments (DMTs) has generated interest in the identification of reliable and robust predictors of treatment switching across different countries, DMTs, and time periods.

Objective

The objective of this retrospective, observational study was to identify independent predictors of treatment switching in a population of relapsing-remitting MS (RRMS) patients in the Big Multiple Sclerosis Data Network of national clinical registries, including the Italian MS registry, the OFSEP of France, the Danish MS registry, the Swedish national MS registry, and the international MSBase Registry.

Methods

In this cohort study, we merged information on 269,822 treatment episodes in 110,326 patients from 1997 to 2018 from five clinical registries. Patients were included in the final pooled analysis set if they had initiated at least one DMT during the relapsing-remitting MS (RRMS) stage. Patients not diagnosed with RRMS or RRMS patients not initiating DMT therapy during the RRMS phase were excluded from the analysis. The primary study outcome was treatment switching. A multilevel mixed-effects shared frailty time-to-event model was used to identify independent predictors of treatment switching. The contributing MS registry was included in the pooled analysis as a random effect.

Results

Every one-point increase in the Expanded Disability Status Scale (EDSS) score at treatment start was associated with 1.08 times the rate of subsequent switching, adjusting for age, sex, and calendar year (adjusted hazard ratio [aHR] 1.08; 95% CI 1.07-1.08). Women were associated with 1.11 times the rate of switching relative to men (95% CI 1.08-1.14), whilst older age was also associated with an increased rate of treatment switching. DMTs started between 2007 and 2012 were associated with 2.48 times the rate of switching relative to DMTs that began between 1996 and 2006 (aHR 2.48; 95% CI 2.48-2.56). DMTs started from 2013 onwards were more likely to switch relative to the earlier treatment epoch (aHR 8.09; 95% CI 7.79-8.41; reference = 1996-2006).

Conclusion

Switching between DMTs is associated with female sex, age, and disability at baseline and has increased in frequency considerably in recent years as more treatment options have become available. Consideration of a patient's individual risk and tolerance profile needs to be taken into account when selecting the most appropriate switch therapy from an expanding array of treatment choices.

Comparison of 2 Methods for Estimating Multiple Sclerosis-Related Mortality

BACKGROUND AND OBJECTIVES

Determining whether multiple sclerosis (MS) causes death is challenging. Our objective was to contrast 2 frameworks to estimate probabilities of death attributed to MS (PMS) and other causes (Pother): the cause-specific framework (CSF), which requires the causes of death, and the excess mortality framework (EMF), which does not.

METHODS

We used data from the Observatoire Français de la Sclérose en Plaques (OFSEP, n = 37,524) and from a comparative subset where causes of death were available (4,004 women with relapsing-onset MS [R-MS]). In CSF, the probabilities were estimated using the Aalen-Johansen method. In EMF, they were estimated from the excess mortality hazard, which is the additional mortality among patients with MS as compared with the expected mortality in the matched general population. PMS values were estimated at 30 years of follow-up, (1) with both frameworks in the comparative subset, by age group at onset, and (2) with EMF only in the OFSEP population, by initial phenotype, sex, and age at onset.

RESULTS

In the comparative subset, the estimated 30-year PMS values were greater using EMF than CSF: 10.9% (95% CI 8.3-13.6) vs 8.7% (6.4-11.8) among the youngest and 20.4% (11.3-29.5) vs 16.2% (8.7-30.2) for the oldest groups, respectively. In the CSF, probabilities of death from unknown causes ranged from 1.5% (0.7-3.0) to 6.4% (2.5-16.4), and even after their reallocation, PMS values remained lower with CSF than with EMF. The estimated probabilities of being alive were close using the 2 frameworks, and the estimated POther (EMF vs CSF) was 2.6% (2.5-2.6) vs 2.1% (1.2-3.9) and 18.1% (16.9-19.3) vs 26.4% (16.5-42.2), respectively, for the youngest and oldest groups. In the OFSEP population, the estimated 30-year PMS values ranged from 7.5% (6.4-8.7) to 24.0% (19.1-28.9) in patients with R-MS and from 25.4% (21.1-29.7) to 36.8% (28.3-45.3) in primary progressive patients, depending on sex and age.

DISCUSSION

EMF has the great advantage of not requiring death certificates, their quality being less than optimal. Conceptually, it also seems more relevant because it avoids having to state, for each individual, whether death was directly or indirectly caused by MS or whether it would have occurred anyway, which is especially difficult in such chronic diseases.

Lifespan neurodegeneration of the human brain in multiple sclerosis

Atrophy related to multiple sclerosis (MS) has been found at the early stages of the disease. However, the archetype dynamic trajectories of the neurodegenerative process, even prior to clinical diagnosis, remain unknown. We modeled the volumetric trajectories of brain structures across the entire lifespan using 40,944 subjects (38,295 healthy controls and 2649 MS patients). Then, we estimated the chronological progression of MS by assessing the divergence of lifespan trajectories between normal brain charts and MS brain charts. Chronologically, the first affected structure was the thalamus, then the putamen and the pallidum (around 4 years later), followed by the ventral diencephalon (around 7 years after thalamus) and finally the brainstem (around 9 years after thalamus). To a lesser extent, the anterior cingulate gyrus, insular cortex, occipital pole, caudate and hippocampus were impacted. Finally, the precuneus and accumbens nuclei exhibited a limited atrophy pattern. Subcortical atrophy was more pronounced than cortical atrophy. The thalamus was the most impacted structure with a very early divergence in life. Our experiments showed that lifespan models of most impacted structures could be an important tool for future preclinical/prodromal prognosis and monitoring of MS.

A Weakly Supervised Gradient Attribution Constraint for Interpretable Classification and Anomaly Detection

The lack of interpretability of deep learning reduces understanding of what happens when a network does not work as expected and hinders its use in critical fields like medicine, which require transparency of decisions. For example, a healthy vs pathological classification model should rely on radiological signs and not on some training dataset biases. Several post-hoc models have been proposed to explain the decision of a trained network. However, they are very seldom used to enforce interpretability during training and none in accordance with the classification. In this paper, we propose a new weakly supervised method for both interpretable healthy vs pathological classification and anomaly detection. A new loss function is added to a standard classification model to constrain each voxel of healthy images to drive the network decision towards the healthy class according to gradient-based attributions. This constraint reveals pathological structures for patient images, allowing their unsupervised segmentation. Moreover, we advocate both theoretically and experimentally, that constrained training with the simple Gradient attribution is similar to constraints with the heavier Expected Gradient, consequently reducing the computational cost. We also propose a combination of attributions during the constrained training making the model robust to the attribution choice at inference. Our proposition was evaluated on two brain pathologies: tumors and multiple sclerosis. This new constraint provides a more relevant classification, with a more pathology-driven decision. For anomaly detection, the proposed method outperforms state-of-the-art especially on difficult multiple sclerosis lesions segmentation task with a 15 points Dice improvement.

Radiologically isolated syndrome

Individuals can be deemed to have radiologically isolated syndrome (RIS) if they have incidental demyelinating-appearing lesions in their brain or spinal cord that are highly suggestive of multiple sclerosis but their clinical history does not include symptoms consistent with multiple sclerosis. Data from international longitudinal cohorts indicate that around half of people with RIS will develop relapsing or progressive symptoms of multiple sclerosis within 10 years, suggesting that in some individuals, RIS is a presymptomatic stage of multiple sclerosis. Risk factors for progression from RIS to clinical multiple sclerosis include younger age (ie, <35 years), male sex, CSF-restricted oligoclonal bands, spinal cord or infratentorial lesions, and gadolinium-enhancing lesions. Other imaging, biological, genetic, and digital biomarkers that might be of value in identifying individuals who are at the highest risk of developing multiple sclerosis need further investigation. Two 2-year randomised clinical trials showed the efficacy of approved multiple sclerosis immunomodulatory medications in preventing the clinical conversion to multiple sclerosis in some individuals with RIS. If substantiated in longer-term studies, these data have the potential to transform our approach to care for the people with RIS who are at the greatest risk of diagnosis with multiple sclerosis.

Investigating the Long-term Effect of Pregnancy on the Course of Multiple Sclerosis Using Causal Inference

BACKGROUND AND OBJECTIVES

The question of the long-term safety of pregnancy is a major concern in patients with multiple sclerosis (MS), but its study is biased by reverse causation (women with higher disability are less likely to experience pregnancy). Using a causal inference approach, we aimed to estimate the unbiased long-term effects of pregnancy on disability and relapse risk in patients with MS and secondarily the short-term effects (during the perpartum and postpartum years) and delayed effects (occurring beyond 1 year after delivery).

METHODS

We conducted an observational cohort study with data from patients with MS followed in the Observatoire Français de la Sclérose en Plaques registry between 1990 and 2020. We included female patients with MS aged 18-45 years at MS onset, clinically followed up for more than 2 years, and with ≥3 Expanded Disease Status Scale (EDSS) measurements. Outcomes were the mean EDSS score at the end of follow-up and the annual probability of relapse during follow-up. Counterfactual outcomes were predicted using the longitudinal targeted maximum likelihood estimator in the entire study population. The patients exposed to at least 1 pregnancy during their follow-up were compared with the counterfactual situation in which, contrary to what was observed, they would not have been exposed to any pregnancy. Short-term and delayed effects were analyzed from the first pregnancy of early-exposed patients (who experienced it during their first 3 years of follow-up).

RESULTS

We included 9,100 patients, with a median follow-up duration of 7.8 years, of whom 2,125 (23.4%) patients were exposed to at least 1 pregnancy. Pregnancy had no significant long-term causal effect on the mean EDSS score at 9 years (causal mean difference [95% CI] = 0.00 [-0.16 to 0.15]) or on the annual probability of relapse (causal risk ratio [95% CI] = 0.95 [0.93-1.38]). For the 1,253 early-exposed patients, pregnancy significantly decreased the probability of relapse during the perpartum year and significantly increased it during the postpartum year, but no significant delayed effect was found on the EDSS and relapse rate.

DISCUSSION

Using a causal inference approach, we found no evidence of significantly deleterious or beneficial long-term effects of pregnancy on disability. The beneficial effects found in other studies were probably related to a reverse causation bias.

Lifespan Neurodegeneration Of The Human Brain In Multiple Sclerosis

Background

Atrophy related to Multiple Sclerosis (MS) has been found at the early stages of the disease. However, the archetype dynamic trajectories of the neurodegenerative process, even prior to clinical diagnosis, remain unknown.

Methods

We modeled the volumetric trajectories of brain structures across the entire lifespan using 40944 subjects (38295 healthy controls and 2649 MS patients). Then, we estimated the chronological progression of MS by assessing the divergence of lifespan trajectories between normal brain charts and MS brain charts.

Results

Chronologically, the first affected structure was the thalamus, then the putamen and the pallidum (3 years later), followed by the ventral diencephalon (7 years after thalamus) and finally the brainstem (9 years after thalamus). To a lesser extent, the anterior cingulate gyrus, insular cortex, occipital pole, caudate and hippocampus were impacted. Finally, the precuneus and accumbens nuclei exhibited a limited atrophy pattern.

Conclusion

Subcortical atrophy was more pronounced than cortical atrophy. The thalamus was the most impacted structure with a very early divergence in life. It paves the way toward utilization of these lifespan models for future preclinical/prodromal prognosis and monitoring of MS.

A decade of fingolimod in multiple sclerosis: Insights from a large real-world cohort study

BACKGROUND AND OBJECTIVES

Ten years after its authorization, data about fingolimod use in real-world setting is still scarce. Here we describe the long-term evolution of fingolimod-treated relapsing-remitting MS (RRMS) patients and determine baseline characteristics associated with risk of relapses or disability.

METHODS

We analyzed baseline characteristics and clinical evolution of 1227 patients with RRMS treated with fingolimod from 2010 to 2019 in 4 French MS referral centers. We used Cox models to determine risks factors of relapses and sustained EDSS worsening.

RESULTS

Median follow-up duration was 50 months, and 63% of patients remained fingolimod-treated at the end of follow-up. Mean 5-years annualized relapse rate (ARR) decreased from 0.63 (0.60-0.67) to 0.26 (0.24-0.29, P<0.001), while the mean EDSS rose from 2.5 (2.4-2.6) to 3.0 (2.8-3.1, P<0.001). Female sex, lower age, higher EDSS and use of natalizumab were associated with relapse risk. Female sex was associated with sustained EDSS increase risk.

CONCLUSIONS

Based on a large real-world cohort, our results confirm the durable reduction of the ARR described in pivot studies. Switching from moderate-efficacy DMT to fingolimod decreased the relapse risk. Switching patients from high-efficacy DMT increased risk of relapse, but the overall five-years ARR remained stable.

Pregnancy and post-partum in patients with myelin-oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND AND OBJECTIVE

Myelin-oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) frequently initiates during childbearing years. This study investigated the impact of pregnancy and post-partum on MOGAD activity.

METHODS

Retrospective analysis of clinical and demographic data from a multicenter French cohort of adult patients with MOGAD. All adult female patients who had a pregnancy after disease onset or in the year before disease onset were included. The annualized relapse rate was evaluated in patients who had a pregnancy after disease onset, to evaluate the impact of pregnancy and post-partum on MOGAD course.

RESULTS

Twenty-five informative pregnancies after disease onset were identified. No relapse was recorded during these pregnancies and only three relapses occurred during the first 3 months post-partum. The annualized relapse rate decreased from 0.67 (95% confidence interval: 0.40-1.10) during the pre-pregnancy period to 0 (95% confidence interval: 0-0.21) during pregnancy and to 0.22 (95% confidence interval: 0.09-0.53) during the first year post-partum. Among 144 female patients in their childbearing age recorded in the database, 18 (12.5%) reported their first symptoms during pregnancy or in the 12 months post-partum.

DISCUSSION

Our study suggests a marked reduction of MOGAD relapse rate during pregnancy and the post-partum period. Prospective studies on the role of pregnancy and delivery in MOGAD course are needed.

Improving the decision to switch from first- to second-line therapy in multiple sclerosis: A dynamic scoring system

BACKGROUND

In relapsing-remitting multiple sclerosis (RRMS), early identification of suboptimal responders can prevent disability progression.

OBJECTIVE

We aimed to develop and validate a dynamic score to guide the early decision to switch from first- to second-line therapy.

METHODS

Using time-dependent propensity scores (PS) from a French cohort of 12,823 patients with RRMS, we constructed one training and two validation PS-matched cohorts to compare the switched patients to second-line treatment and the maintained patients. We used a frailty Cox model for predicting individual hazard ratios (iHRs).

RESULTS

From the validation PS-matched cohort of 348 independent patients with iHR ⩽ 0.69, we reported the 5-year relapse-free survival at 0.14 (95% confidence interval (CI) 0.09-0.22) for the waiting group and 0.40 (95% CI 0.32-0.51) for the switched group. From the validation PS-matched cohort of 518 independent patients with iHR > 0.69, these values were 0.37 (95% CI 0.30-0.46) and 0.44 (95% CI 0.37-0.52), respectively.

CONCLUSIONS

By using the proposed dynamic score, we estimated that at least one-third of patients could benefit from an earlier switch to prevent relapse.

Effects of socioeconomic status on excess mortality in patients with multiple sclerosis in France: A retrospective observational cohort study

Background

The effects of socio-economic status on mortality in patients with multiple sclerosis is not well known. The objective was to examine mortality due to multiple sclerosis according to socio-economic status.

Methods

A retrospective observational cohort design was used with recruitment from 18 French multiple sclerosis expert centers participating in the Observatoire Français de la Sclérose en Plaques. All patients lived in metropolitan France and had a definite or probable diagnosis of multiple sclerosis according to either Poser or McDonald criteria with an onset of disease between 1960 and 2015. Initial phenotype was either relapsing-onset or primary progressive onset. Vital status was updated on January 1st 2016. Socio-economic status was measured by an ecological index, the European Deprivation Index and was attributed to each patient according to their home address. Excess death rates were studied according to socio-economic status using additive excess hazard models with multidimensional penalised splines. The initial hypothesis was a potential socio-economic gradient in excess mortality.

Findings

A total of 34,169 multiple sclerosis patients were included (88% relapsing onset (n = 30,083), 12% progressive onset (n = 4086)), female/male sex ratio 2.7 for relapsing-onset and 1.3 for progressive-onset). Mean age at disease onset was 31.6 (SD = 9.8) for relapsing-onset and 42.7 (SD = 10.8) for progressive-onset. At the end of follow-up, 1849 patients had died (4.4% for relapsing-onset (n = 1311) and 13.2% for progressive-onset (n = 538)). A socio-economic gradient was found for relapsing-onset patients; more deprived patients had a greater excess death rate. At thirty years of disease duration and a year of onset of symptoms of 1980, survival probability difference (or deprivation gap) between less deprived relapsing-onset patients (EDI = −6) and more deprived relapsing-onset patients (EDI = 12) was 16.6% (95% confidence interval (CI) [10.3%–22.9%]) for men and 12.3% (95%CI [7.6%–17.0%]) for women. No clear socio-economic mortality gradient was found in progressive-onset patients.

Interpretation

Socio-economic status was associated with mortality due to multiple sclerosis in relapsing-onset patients. Improvements in overall care of more socio-economically deprived patients with multiple sclerosis could help reduce these socio-economic inequalities in multiple sclerosis-related mortality.

Funding

This study was funded by the ARSEP foundation “Fondation pour l'aide à la recherche sur la Sclérose en Plaques” (Grant Reference Number 1122). Data collection has been supported by a grant provided by the French State and handled by the “Agence Nationale de la Recherche,” within the framework of the “Investments for the Future” programme, under the reference ANR-10-COHO-002, Observatoire Français de la Sclérose en Plaques (OFSEP).

Disease modifying therapies and disease activity during pregnancy and postpartum in a contemporary cohort of relapsing Multiple Sclerosis patients

BACKGROUND

In Multiple Sclerosis (MS) women, therapeutic management for pregnancy planning and during pregnancy still represents a challenge regarding timing of disease-modifying therapies (DMT) stop, risk of disease reactivation and potential fetal toxicity. The objective of this study was to describe disease activity during pregnancy and postpartum depending on treatment status before conception in women with MS.

METHODS

339 MS patients who have achieved a pregnancy between 2007 and 2017 were included. Women were classified according to their exposure to DMT in the 18 months period prior to pregnancy (untreated / first- / second/third-line treatment).

RESULTS

122 women were not exposed to DMT prior to conception, whereas 147 were exposed to first-line DMT and 70 to second/third line DMT (73% to natalizumab and 23% to fingolimod) before conception. In the first-line group, the ARR decreased from 0.39 during the year before conception to 0.21 during pregnancy, whereas it increased in the second/third-line group from 0.59 to 0.78. 47.1% of the second/third-line group faced at least one relapse during pregnancy and the time from conception to first relapse was significantly shorter in this group (p < 10^-4). The risk of relapse during pregnancy and postpartum was associated with occurrence of pre-conception relapses and second/third line DMT exposure before pregnancy.

CONCLUSION

Careful consideration should be given to natalizumab and fingolimod exposed patients before conception as they are at higher risk of reactivation of MS during pregnancy.

New multiple sclerosis lesion segmentation and detection using pre-activation U-Net

Automated segmentation of new multiple sclerosis (MS) lesions in 3D MRI data is an essential prerequisite for monitoring and quantifying MS progression. Manual delineation of such lesions is time-consuming and expensive, especially because raters need to deal with 3D images and several modalities. In this paper, we propose Pre-U-Net, a 3D encoder-decoder architecture with pre-activation residual blocks, for the segmentation and detection of new MS lesions. Due to the limited training set and the class imbalance problem, we apply intensive data augmentation and use deep supervision to train our models effectively. Following the same U-shaped architecture but different blocks, Pre-U-Net outperforms U-Net and Res-U-Net on the MSSEG-2 dataset, achieving a Dice score of 40.3% on new lesion segmentation and an F₁ score of 48.1% on new lesion detection. The codes and trained models are publicly available at https://github.com/pashtari/xunet.

Assessing the Risk of Relapse Requiring Corticosteroids After In Vitro Fertilization in Women With Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Several studies have shown an increased risk of relapse after in vitro fertilization (IVF) in women with multiple sclerosis (MS), especially when a gonadotrophin-releasing hormone (GnRH) agonist stimulation protocol was used. Our objective was to investigate the risk of relapse after IVF in women with MS, overall and according to stimulation protocol (GnRH agonists vs antagonists), using data from the French national health insurance database.

METHODS

This retrospective cohort study included all women with MS who have benefited from IVF between January 1, 2010, and December 31, 2015, in France. Three-month exposed periods after IVF were compared with unexposed periods before IVF, each woman being her own control. Four outcomes were considered: annualized relapse rate (ARR), proportion of IVF with relapse, difference in the number of relapses "after-before," and the delay from IVF to the first relapse. Relapses were identified by an algorithm based on MS-related hospital admissions and the use of corticosteroid therapy. Stimulation protocols and disease-modifying therapies (DMTs) were identified using drug claims. Zero-inflated Poisson regression models adjusted for age at IVF and the presence of DMT were used. A random effect on women was included because women may undergo multiple IVF procedures. Subgroup analyses by stimulation protocol and IVF outcome (pregnancy or failure) were conducted.

RESULTS

A total of 225 women accounting for 338 IVF procedures were included (the mean age at the first IVF 34.6 ± 4.5 years; 36% of women underwent at least 2 IVF procedures during the period). No increase in the risk of relapse after IVF was found overall (before vs after IVF: 0.20 vs 0.18 relapse per patient-year; 7.7% vs 7.1% of IVF with women having at least one relapse) and in subgroups. A lower ARR before and after IVF was observed among women who remained treated until IVF.

DISCUSSION

The maintenance of DMT until IVF seemed to be a determining factor in reducing the risk of relapse. Women with MS should be reassured because we did not show an increased risk of relapse requiring the use of corticosteroid therapy after IVF neither with GnRH agonists nor with GnRH antagonists.

Overall and patient-level comparative effectiveness of dimethyl fumarate and fingolimod: A precision medicine application to the Observatoire Français de la Sclérose en Plaques registry

Background

Comparing real-world effectiveness and tolerability of therapies for relapsing-remitting multiple sclerosis is increasingly important, though average treatment effects fail to capture possible treatment effect heterogeneity. With the clinical course of the disease being highly heterogeneous across patients, precision medicine methods enable treatment response heterogeneity investigations.

Objective

To compare real-world effectiveness and discontinuation profiles between dimethyl fumarate and fingolimod while investigating treatment effect heterogeneity with precision medicine methods.

Methods

Adults initiating dimethyl fumarate or fingolimod as a second-line therapy were selected from a French registry. The primary outcome was annualized relapse rate at 12 months. Seven secondary outcomes relative to discontinuation and disease progression were considered. A precision medicine framework was used to characterize treatment effect heterogeneity.

Results

Annualized relapse rates at 12 months were similar for dimethyl fumarate and fingolimod. The odd of treatment persistence was 47% lower for patients treated with dimethyl fumarate relative to those treated with fingolimod (odds ratio: 0.53, 95% confidence interval: 0.39, 0.70). None of the five precision medicine scoring approaches identified treatment heterogeneity.

Conclusion

These findings substantiated the similar effectiveness and different discontinuation profiles for dimethyl fumarate and fingolimod as a second-line therapy for relapsing-remitting multiple sclerosis, with no significant effect heterogeneity observed.

COPP-MS: COrticosteroids during the Post-Partum in relapsing Multiple Sclerosis patients

BACKGROUND

No specific treatment has demonstrated its effectiveness to prevent post-partum relapses for multiple sclerosis (MS) women.

OBJECTIVE

To assess the effectiveness of preventive high-dose corticosteroids in the post-partum period by comparing two strategies: (1) no preventive treatment and (2) standardized preventive treatment.

METHODS

We selected five French Multiple Sclerosis centers using the same post-partum strategy for their patients-either high-dose steroids (treating centers TC) or no treatment (non-treating centers NTC). We included relapsing-remitting multiple sclerosis women who delivered between January 2007 and January 2017. Our primary outcomes were the time from delivery to first relapse, EDSS progression and MRI activity between patients of treating centers and non-treating centers, after propensity-score weighting.

RESULTS

350 patients were included (116 from treating centers, 234 from non-treating centers). For both groups, the annualized relapse rate decreased during pregnancy (0.28 in treating centers and 0.34 in non-treating centers during the third trimester) and increased during the first post-partum trimester (0.45 and 0.69, respectively) with 11% and 14% (NS) of patients facing at least one relapse, respectively. Our primary outcomes were not statistically different between both groups.

CONCLUSION

This study provides class III evidence that systematic high-dose corticosteroids are not associated with a reduced inflammatory activity during the post-partum period in multiple sclerosis patients.

Impact of methodological choices in comparative effectiveness studies: application in natalizumab versus fingolimod comparison among patients with multiple sclerosis

Background

Natalizumab and fingolimod are used as high-efficacy treatments in relapsing–remitting multiple sclerosis. Several observational studies comparing these two drugs have shown variable results, using different methods to control treatment indication bias and manage censoring. The objective of this empirical study was to elucidate the impact of methods of causal inference on the results of comparative effectiveness studies.

Methods

Data from three observational multiple sclerosis registries (MSBase, the Danish MS Registry and French OFSEP registry) were combined. Four clinical outcomes were studied. Propensity scores were used to match or weigh the compared groups, allowing for estimating average treatment effect for treated or average treatment effect for the entire population. Analyses were conducted both in intention-to-treat and per-protocol frameworks. The impact of the positivity assumption was also assessed.

Results

Overall, 5,148 relapsing–remitting multiple sclerosis patients were included. In this well-powered sample, the 95% confidence intervals of the estimates overlapped widely. Propensity scores weighting and propensity scores matching procedures led to consistent results. Some differences were observed between average treatment effect for the entire population and average treatment effect for treated estimates. Intention-to-treat analyses were more conservative than per-protocol analyses. The most pronounced irregularities in outcomes and propensity scores were introduced by violation of the positivity assumption.

Conclusions

This applied study elucidates the influence of methodological decisions on the results of comparative effectiveness studies of treatments for multiple sclerosis. According to our results, there are no material differences between conclusions obtained with propensity scores matching or propensity scores weighting given that a study is sufficiently powered, models are correctly specified and positivity assumption is fulfilled.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01623-8.

Disability Progression in Multiple Sclerosis Patients using Early First-line Treatments

BACKGROUND

Therapeutic management of relapsing-remitting multiple sclerosis (RRMS) has evolved towards early treatment. The objective was to assess the impact of early treatment initiation on disability progression among RRMS first-line treated patients.

METHODS

This study included all incident RRMS cases starting interferon or glatiramer acetate for the first time from 1996/01/01 to 2012/31/12 (N=5,279) from ten MS expert OFSEP centers (Observatoire Français de la Sclérose en Plaques). The delay from treatment start to attain an irreversible Expanded Disability Status Scale score of 3.0 were compared between "Early" group (N= 1,882; treated within 12 months following MS clinical onset) and "Later" group using propensity score weighted Kaplan-Meier methods, overall and stratified by age.

RESULTS

Overall, the restricted mean time before reaching EDSS 3.0 (RMST) from treatment start was 11 years and two months for patients treated within the year following MS clinical onset and 10 years and seven months for patients treated later. Thus, early treated patients gained 7 months (95% CI: [4-11] months) in the time to reach EDSS 3.0 compared to patients treated later (treatment start delayed by 28 months). The difference in RMST was respectively six months (95% CI: [1-10] months) and 14 months (95% CI: [4-24] months) in the "≤40 years" age group and in the ">40 years" age group, in favour of early group. .

CONCLUSIONS

Early treatment initiation resulted in a significant reduction of disability progression among patients with RRMS, and also among older patients.

Comparative Effectiveness of Natalizumab Versus Anti-CD20 in Highly Active Relapsing-Remitting Multiple Sclerosis After Fingolimod Withdrawal

In France, two therapeutic strategies can be offered after fingolimod (FNG) withdrawal to highly active relapsing-remitting multiple sclerosis (RRMS) patients: natalizumab (NTZ) or anti-CD20. We compared the effectiveness of these two strategies as a switch for FNG within the OFSEP database. The primary endpoint was the time to first relapse. Other outcomes were the relapse rates over 3-month periods, time to worsening the EDSS score, proportion of patients with worsened 24-month MRI, time to treatment discontinuation, and incidence rates of serious adverse events. The dynamics of event rates over time were modeled using multidimensional penalized splines, allowing the possibility to model the effects of covariates in a flexible way, considering non-linearity and interactions. A total of 740 patients were included (337 under anti-CD20 and 403 under NTZ). There was no difference between the two treatments regarding the dynamic of the first occurrence of relapse, with a monthly probability of 5.0% at initiation and 1.0% after 6 months. The rate of EDSS worsening increased in both groups until 6 months and then decreased. No difference in the proportion of patients with new T2 lesions at 24 months was observed. After 18 months of follow-up, a greater risk of NTZ discontinuation was found compared to anti-CD20. This study showed no difference between NTZ and anti-CD20 after the FNG switch regarding the clinical and radiological activity. The effect of these treatments was optimal after 6 months and there was more frequent discontinuation of NTZ after 18 months, probably mainly related to JC virus seroconversions.

Effectiveness of Anti-Cluster of Differentiation 20 as a Disease-Modifying Therapy in Multiple Sclerosis Across Its Different Phenotypes at the University Hospital of Caen

Background

Multiple sclerosis is a chronic, demyelinating disorder occurring primarily as two main forms of relapsing-remitting multiple sclerosis (RRMS) found predominantly in women, and primary progressive multiple sclerosis (PPMS) occurring predominantly in men. In this retrospective single-center study, we aimed to explore the effects of anti-cluster of differentiation (CD)20 treatment for both relapsing-remitting and primary progressive forms of multiple sclerosis (MS) in a population-based cohort treated at the university hospital. 

Methodology

The diagnostic factors being assessed were forms of multiple sclerosis (MS), age at first relapse, whereas therapeutic factors were age at first disease-modifying therapy (DMT), age at starting anti-CD20, reason to switch to anti-CD20 and the duration of anti-CD20 treatment. Primary outcomes measured were number of relapses and progression in disability as measured by the Expanded Disability Status Scale, while secondary outcomes measures being assessed number of cerebral lesions on MRI and level of IgG at the beginning and end of the 12-month treatment.

Results

Treatment with anti-CD20 demonstrated a reduction in number of relapses 12 months after treatment, no change in the progression of disability in RRMS type, but an increase in PPMS type. No change was observed in cerebral MRI lesions at the end of treatment after 12 months. A statistically significant reduction in serum IgG value was observed after 12 months from the start of treatment, where only one out of 26 (3.8%) patients developed hypogammaglobulinemia with IgG less than 6 g/L but none developed hypogammaglobulinemia of less than 5 g/L.

Conclusion

Anti-CD20 antibodies as disease-modifying therapy can profoundly impact the course and progression of MS in both its forms if utilized at an earlier stage in patients and therefore greatly improve the quality of life in patients living with multiple sclerosis.

Multiple sclerosis lesions segmentation from multiple experts: The MICCAI 2016 challenge dataset

MRI plays a crucial role in multiple sclerosis diagnostic and patient follow-up. In particular, the delineation of T2-FLAIR hyperintense lesions is crucial although mostly performed manually - a tedious task. Many methods have thus been proposed to automate this task. However, sufficiently large datasets with a thorough expert manual segmentation are still lacking to evaluate these methods. We present a unique dataset for MS lesions segmentation evaluation. It consists of 53 patients acquired on 4 different scanners with a harmonized protocol. Hyperintense lesions on FLAIR were manually delineated on each patient by 7 experts with control on T2 sequence, and gathered in a consensus segmentation for evaluation. We provide raw and preprocessed data and a split of the dataset into training and testing data, the latter including data from a scanner not present in the training dataset. We strongly believe that this dataset will become a reference in MS lesions segmentation evaluation, allowing to evaluate many aspects: evaluation of performance on unseen scanner, comparison to individual experts performance, comparison to other challengers who already used this dataset, etc.

Natalizumab Versus Fingolimod in Patients with Relapsing-Remitting Multiple Sclerosis: A Subgroup Analysis From Three International Cohorts

INTRODUCTION

Natalizumab has proved to be more effective than fingolimod in reducing disease activity in relapsing-remitting multiple sclerosis (RRMS). Whether this association is universal for all patient groups remains to be determined.

OBJECTIVE

The aim of this study was to compare the relative effectiveness of natalizumab and fingolimod in RRMS subgroups defined by the baseline demographic and clinical characteristics of interest.

METHODS

Patients with RRMS who were given natalizumab or fingolimod were identified in a merged cohort from three international registries. Efficacy outcomes were compared across subgroups based on patients' sex, age, disease duration, Expanded Disability Status Scale (EDSS) score, and disease and magnetic resonance imaging (MRI) activity 12 months prior to treatment initiation. Study endpoints were number of relapses (analyzed with weighted negative binomial generalized linear model) and 6-month confirmed disability worsening and improvement events (weighted Cox proportional hazards model), recorded during study therapy. Each patient was weighted using inverse probability of treatment weighting based on propensity score.

RESULTS

A total of 5148 patients (natalizumab 1989; fingolimod 3159) were included, with a mean ± standard deviation age at baseline of 38 ± 10 years, and the majority (72%) were women. The median on-treatment follow-up was 25 (quartiles 15-41) months. Natalizumab was associated with fewer relapses than fingolimod (incidence rate ratio [IRR]; 95% confidence interval [CI]) in women (0.76; 0.65-0.88); in those aged ≤ 38 years (0.64; 0.54-0.76); in those with disease duration ≤ 7 years (0.63; 0.53-0.76); in those with EDSS score < 4 (0.75; 0.64-0.88), < 6 (0.80; 0.70-0.91), and ≥ 6 (0.52; 0.31-0.86); and in patients with pre-baseline relapses (0.74; 0.64-0.86). A higher probability of confirmed disability improvement on natalizumab versus fingolimod (hazard ratio [HR]; 95% CI) was observed among women (1.36; 1.10-1.66); those aged > 38 years (1.34; 1.04-1.73); those with disease duration > 7 years (1.33; 1.01-1.74); those with EDSS score < 6 (1.21; 1.01-1.46) and ≥ 6 (1.93; 1.11-3.34); and patients with no new MRI lesion (1.73; 1.19-2.51).

CONCLUSIONS

Overall, in women, younger patients, those with shorter disease durations, and patients with pre-treatment relapses, natalizumab was associated with a lower frequency of multiple sclerosis relapses than fingolimod. It was also associated with an increased chance of recovery from disability among most patients, particularly women and those with no recent MRI activity.

NARCOMS and Other Registries in Multiple Sclerosis: Issues and Insights

Observational studies and registries can play a critical role in elucidating the natural and treated history of multiple sclerosis (MS) and identifying factors associated with outcomes such as disability and health-related quality of life. The North American Research Committee on Multiple Sclerosis (NARCOMS) Registry is one of multiple registries worldwide that focuses on people with MS, but one of the very few patient-driven MS registries. On the 25th anniversary of the first data collection for the NARCOMS Registry, we discuss the importance of disease registries in the MS field, describe key concepts related to registry design and management, and highlight findings from MS registries relevant to clinical care or health policy.

Risk Factors and Time to Clinical Symptoms of Multiple Sclerosis Among Patients With Radiologically Isolated Syndrome

IMPORTANCE

Younger age, oligoclonal bands, and infratentorial and spinal cord lesions are factors associated with an increased 10-year risk of clinical conversion from radiologically isolated syndrome (RIS) to multiple sclerosis (MS). Whether disease-modifying therapy is beneficial for individuals with RIS is currently unknown.

OBJECTIVES

To evaluate the 2-year risk of a clinical event (onset of clinical symptoms of MS) prospectively, identify factors associated with developing an early clinical event, and simulate the sample size needed for a phase III clinical trial of individuals with RIS meeting 2009 RIS criteria.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data on prospectively followed-up individuals with RIS identified at 1 of 26 tertiary centers for MS care in France that collect data for the Observatoire Français de la Sclérose en Plaques database. Participants were aged 10 to 80 years with 2 or more magnetic resonance imaging (MRI) scans after study entry and an index scan after 2000. All diagnoses were validated by an expert group, whose review included a double centralized MRI reading. Data were analyzed from July 2020 to January 2021.

EXPOSURE

Diagnosis of RIS.

MAIN OUTCOMES AND MEASURES

Risk of clinical event and associated covariates at index scan were analyzed among all individuals with RIS. Time to the first clinical event was compared by covariates, and sample size estimates were modeled based on identified risk factors.

RESULTS

Among 372 individuals with RIS (mean [SD] age at index MRI scan, 38.6 [12.1] years), 354 individuals were included in the analysis (264 [74.6%] women). A clinical event was identified among 49 patients (13.8%) within 2 years, which was associated with an estimated risk of conversion of 19.2% (95% CI, 14.1%-24.0%). In multivariate analysis, age younger than 37 years (hazard ratio [HR], 4.04 [95% CI, 2.00-8.15]; P < .001), spinal cord lesions (HR, 5.11 [95% CI, 1.99-13.13]; P = .001), and gadolinium-enhancing lesions on index scan (HR, 2.09 [95% CI, 1.13-3.87]; P = .02) were independently associated with an increased risk of conversion to MS. Having 2 factors at the time of the index MRI scan was associated with a risk of 27.9% (95% CI, 13.5%-39.9%) of a seminal event within 2 years, increasing to 90.9% (95% CI, 41.1%-98.6%) for individuals with all 3 factors (3 risk factors vs none: HR, 23.34 [95% CI, 9.08-59.96]; P < .001). Overall, with 80% power to detect an effect size of 60% within 24 months, a total of 160 individuals with RIS were needed assuming an event rate of 20%.

CONCLUSIONS AND RELEVANCE

This study found that age younger than age 37 years, spinal cord involvement, and gadolinium-enhancing lesions on index MRI scan were associated with earlier clinical disease and relevant to the number of enrolled patients needed to detect a potential treatment effect.

Effects of High and Low Efficacy Therapy in Secondary Progressive Multiple Sclerosis

OBJECTIVE

To compare the clinical effectiveness of high- and low-efficacy treatments in patients with recently active and inactive secondary progressive multiple sclerosis (SPMS) after accounting for therapeutic lag.

METHODS

Patients treated with high- (natalizumab, alemtuzumab, mitoxantrone, ocrelizumab, rituximab, cladribine, fingolimod) or low-efficacy (interferon β, glatiramer acetate, teriflunomide) therapies after SPMS onset were selected from MSBase and OFSEP, two large observational cohorts. Therapeutic lag was estimated for each patient based on their demographic and clinical characteristics. Propensity score was used to match patients treated with high and low-efficacy therapies. Outcomes after disregarding the period of therapeutic lag were compared in paired, pairwise-censored analyses.

RESULTS

1000 patients were included in the primary analysis. Patients with active SPMS treated with high-efficacy therapy experienced less frequent relapses than those on low-efficacy therapy (hazard ratio [HR] 0.7, p=0.006). In patients with inactive SPMS, there was no evidence for a difference in relapse frequency between groups (HR=0.8,p=0.39). No evidence for a difference in the risk of disability progression was observed.

CONCLUSION

In treated patients with SPMS, high-efficacy therapy is superior to low-efficacy therapy in reducing relapses in patients with active, but not those with inactive, SPMS. However, more potent therapies do not offer an advantage in reducing disability progression in this patient group.

CLASSIFICATION OF EVIDENCE

This study provides class III evidence that high-efficacy therapy is superior to low-efficacy therapy in reducing relapses in patients with active SPMS whilst we did not find a difference in disability progression between patients treated with high- and low-efficacy therapy.

Clinical failure of natalizumab in multiple sclerosis: Specific causes and strategy

BACKGROUND

Natalizumab is a very effective treatment of multiple sclerosis (MS). Failure is rare and should lead to consider some specific etiologies. The purpose of our study was to describe causes of subacute neurological events under natalizumab.

METHODS

Observational single-center retrospective study in the MS expert center of Lyon, France.

INCLUSION CRITERIA

any patient with definite MS who received at least three infusions of natalizumab between April 2007 and February 2017. Clinical data were extracted from the Lyon EDMUS/OFSEP database. Events of interest: occurrence of a subacute neurological deficit, characterized by new clinical symptoms. We excluded pseudo-relapses and progression.

FINDINGS

A subacute neurological deficit occurred in 35 cases, for 607 patients treated with natalizumab. Ten patients presented natalizumab antibodies, nine had progressive multifocal leukoencephalopathy (PML), five presented an isolated subacute neurological deficit and two had AQP4 antibodies. No myelin oligodendrocyte glycoprotein (MOG) antibodies were found.

INTERPRETATION

The occurrence of an acute or subacute neurological deficit with natalizumab is rarely a MS relapse and should lead systematically to explore some important alternate etiologies, eliminating PML first.

Effects of Age and Disease Duration on Excess Mortality in Patients With Multiple Sclerosis From a French Nationwide Cohort

OBJECTIVE

To determine the effects of current age and disease duration on excess mortality in multiple sclerosis (MS), we describe the dynamics of excess death rates over these 2 time scales and study the effect of age at MS clinical onset on these dynamics, separately in each initial phenotype.

METHODS

We used data from 18 French MS expert centers participating in the Observatoire Français de la Sclérose en Plaques. Patients with MS living in metropolitan France and having a clinical onset between 1960 and 2014 were included. Vital status was updated on January 1, 2016. For each MS phenotype separately (relapsing onset [RMS] or primary progressive [PPMS]), we used an innovative statistical method to model the logarithm of excess death rates by a multidimensional penalized spline of age and disease duration.

RESULTS

Among 37,524 patients (71% women, mean age at MS onset ± SD 33.0 ± 10.6 years), 2,883 (7.7%) deaths were observed and 7.8% of patients were lost to follow-up. For patients with RMS, there was no excess mortality during the first 10 years after disease onset; afterwards, whatever the age at onset, excess death rates increased with current age. From current age 70, the excess death rate values converged and became identical whatever the age at disease onset, which means that disease duration had no more effect. Excess death rates were higher in men, with an excess hazard ratio of 1.46 (95% confidence interval 1.25-1.70). In contrast, in patients with PPMS, excess death rates rapidly increased from disease onset, and were associated with age at onset, but not with sex.

CONCLUSIONS

In RMS, current age has a stronger effect on MS mortality than disease duration, while their respective effects are not clear in PPMS.

Multiple sclerosis: Is there a risk of worsening after yellow fever vaccination?

BACKGROUND

Yellow fever vaccine (YFV) is not advised for multiple sclerosis (MS) patients because of the potential risk of post-vaccine relapses.

OBJECTIVE

To assess the risk of relapsing-remitting multiple sclerosis (RR-MS) worsening after YFV.

METHODS

Non-interventional observational retrospective, exposed/non-exposed cohort study nested in the French national cohort including MS.

RESULTS

128 RR-MS were included. The 1-year annualized relapse rate (ARR) following YFV did not differ between exposed: 0.219 (0.420) and non-exposed subjects: 0.208 (0.521) (p = 0.92). Time to first relapse was not different between groups (adjusted hazard ratio (HR) = 1.33; 95% confidence interval (CI) = 0.53-3.30, p = 0.54).

CONCLUSION

These results suggest that YFV does not worsen the course of RR-MS.

Drug safety in multiple sclerosis: From reporting to signal detection and benefit-risk management

BACKGROUND

Pharmacovigilance (PV) rules emerged in the late 60s-early 70s. Since that time, the World Health Organization Center for International Drug Monitoring carries out the corresponding tasks. Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system that generally starts in young adults between 20 and 40 years of age. Over the last 25 years, MS patients have benefited from the development of a plethora of disease modifying drugs (DMD). These changes in the therapeutic armamentarium have been associated with some serious adverse reactions challenging health authorities and neurologists involved in treatment and care for MS patients.

METHODS

The present review aims to describe, for MS DMDs, how adverse drug reactions are reported during clinical trials and the post-marketing period and how important signal detection and benefit-risk management have been in this disease until now. Several examples are reported to illustrate the different steps of PV processes.

CONCLUSION

Improvement of the PV system procedures has led to significant progress in the detection of signals, allowing better assessment of the benefit-risk balance and the implementation of risk management plans for MS treatments. The involvement of neurologists is essential to improve knowledge on the benefit-risk balance of these drugs. In addition, adverse drug reactions reporting by persons with MS should be encouraged.

Untreated patients with multiple sclerosis: A study of French expert centers

BACKGROUND AND PURPOSE

Disease-modifying therapies (DMTs) have an impact on relapses and disease progression. Nonetheless, many patients with multiple sclerosis (MS) remain untreated. The objectives of the present study were to determine the proportion of untreated patients with MS followed in expert centers in France and to determine the predictive factors of nontreatment.

METHODS

We conducted a retrospective cohort study. Data were extracted from the 38 centers participating in the European Database for Multiple Sclerosis (EDMUS) on December 15, 2018, and patients with MS seen at least once during the study period (from June 15, 2016 to June 14, 2017) were included.

RESULTS

Of the 21,189 patients with MS (age 47.1 ± 13.1 years; Expanded Disability Status Scale (EDSS) score 3.4 ± 2.4), 6,631 (31.3%; 95% confidence interval [CI] 30.7-31.9) were not receiving any DMT. Although patients with a relapsing-remitting course (n = 11,693) were the most likely to receive DMT, 14.8% (95% CI 14.2-15.4) were still untreated (6.8% never treated). After multivariate analysis among patients with relapsing-remitting MS, the main factors explaining never having been treated were: not having ≥9 lesions on brain magnetic resonance imaging (odds ratio [OR] 0.52 [95% CI 0.44-0.61]) and lower EDSS score (OR 0.78 [95% CI 0.74-0.82]). Most patients with progressive MS (50.4% for secondary and 64.2% for primary progressive MS) did not receive any DMT during the study period, while 11.6% of patients with secondary and 34.0% of patients with primary progressive MS had never received any DMT.

CONCLUSION

A significant proportion of patients with MS did not receive any DMT, even though such treatments are reimbursed by the healthcare system for French patients. This result highlights the unmet need for current DMTs for a large subgroup of patients with MS.

Pregnancy in Patients With AQP4-Ab, MOG-Ab, or Double-Negative Neuromyelitis Optica Disorder

OBJECTIVE

To analyze the effects of pregnancy on neuromyelitis optica spectrum disorder (NMOSD) according to patients' serostatus and immunosuppressive therapy (IST).

METHODS

We performed a retrospective multicenter international study on patients with NMOSD. Patients were tested for aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibodies (Ab). Informative pregnancies were reported when NMOSD onset occurred before or during pregnancy or up to 12 months postpartum. The mean annualized relapse rate (ARR) was calculated for the 12 months before conception, for each trimester of pregnancy, and postpartum. Events such as miscarriage, abortion, and preeclampsia were reported. IST was considered if taken in the 3 months before or during pregnancy.

RESULTS

We included 89 pregnancies (46 with AQP4-Ab, 30 with MOG-Ab, and 13 without either Ab) in 58 patients with NMOSD. Compared to the prepregnancy period, the ARR was lower during pregnancy in each serostatus group and higher during the postpartum period in patients with AQP4-Ab (p < 0.01). Forty-eight percent (n = 31) of pregnancies occurred during IST and these patients presented fewer relapses during pregnancy and the 12 months postpartum than untreated patients (26% vs 53%, p = 0.04). Miscarriages occurred in 10 (11%) pregnancies, and were mainly in patients with AQP4-Ab (with or without IST) and a previous history of miscarriage. Preeclampsia was reported in 2 (2%) patients who were AQP4-Ab-positive.

CONCLUSION

We found a rebound in the ARR during the first postpartum trimester that was higher than the prepregnancy period only in AQP4-Ab-positive patients. Taking IST just before or during pregnancy reduces the risk of relapses in these conditions.

Determinants of therapeutic lag in multiple sclerosis

BACKGROUND

A delayed onset of treatment effect, termed therapeutic lag, may influence the assessment of treatment response in some patient subgroups.

OBJECTIVES

The objective of this study is to explore the associations of patient and disease characteristics with therapeutic lag on relapses and disability accumulation.

METHODS

Data from MSBase, a multinational multiple sclerosis (MS) registry, and OFSEP, the French MS registry, were used. Patients diagnosed with MS, minimum 1 year of exposure to MS treatment and 3 years of pre-treatment follow-up, were included in the analysis. Studied outcomes were incidence of relapses and disability accumulation. Therapeutic lag was calculated using an objective, validated method in subgroups stratified by patient and disease characteristics. Therapeutic lag under specific circumstances was then estimated in subgroups defined by combinations of clinical and demographic determinants.

RESULTS

High baseline disability scores, annualised relapse rate (ARR) ⩾ 1 and male sex were associated with longer therapeutic lag on disability progression in sufficiently populated groups: females with expanded disability status scale (EDSS) < 6 and ARR < 1 had mean lag of 26.6 weeks (95% CI = 18.2-34.9), males with EDSS < 6 and ARR < 1 31.0 weeks (95% CI = 25.3-36.8), females with EDSS < 6 and ARR ⩾ 1 44.8 weeks (95% CI = 24.5-65.1), and females with EDSS ⩾ 6 and ARR < 1 54.3 weeks (95% CI = 47.2-61.5).

CONCLUSIONS

Pre-treatment EDSS and ARR are the most important determinants of therapeutic lag.

Relapses in Patients Treated with High-Dose Biotin for Progressive Multiple Sclerosis

High-dose biotin (HDB) is a therapy used in non-active progressive multiple sclerosis (PMS). Several reports have suggested that HDB treatment may be associated with an increased risk of relapse. We aimed to determine whether HDB increases the risk of clinical relapse in PMS and describe the characteristics of the patients who experience it. We conducted a French, multicenter, retrospective study, comparing a group of PMS patients treated with HDB to a matched control group. Poisson regression was applied to model the specific statistical distribution of the annualized relapse rate (ARR). A propensity score (PS), based on the inverse probability of treatment weighting (IPTW), was used to adjust for indication bias and included the following variables: gender, primary PMS or not, age, EDSS, time since the last relapse, and co-prescription of a DMT. Two thousand six hundred twenty-eight patients treated with HDB and 654 controls were analyzed with a follow-up of 17 ± 8 months. Among them, 148 validated relapses were observed in the group treated with biotin and 38 in the control group (p = 0.62). After adjustment based on the PS, the ARR was 0.044 ± 0.23 for the biotin-treated group and 0.028 ± 0.16 for the control group (p = 0.18). The more relapses there were before biotin, the higher the risk of relapse during treatment, independently from the use of HDB. While the number of relapses reported for patients with no previous inflammatory activity receiving biotin has gradually increased, the present retrospective study is adequately powered to exclude an elevated risk of relapse for patients with PMS treated with HDB.

First line treatment failure: Predictive factors in a cohort of 863 Relapsing Remitting MS patients

BACKGROUND

The advent of new, potent, disease-modifying therapies has dramatically changed the management of multiple sclerosis (MS). Along with these possibilities, it is crucial to better recognize patients who are at risk of first line treatment (FLT) failure and switch to highly effective therapies (HET).

OBJECTIVES

To identify baseline prognostic factors associated with FLT failure in relapsing remitting MS (RR-MS) patients.

METHODS

We included recently diagnosed RR-MS patients starting an FLT identified from 3 French MS centers databases. Baseline characteristics were included in a multivariable Cox analysis to identify the main factors associated with FLT failure.

RESULTS

Eight hundred sixty-three patients were included. We observed an overall rate of treatment failure of 23.5%. The main baseline characteristics associated with treatment failure were age <26 years at treatment start (HR= 2.1, p<0.001), EDSS ≥2 (HR=2.1, p<0.001) and ≥2relapses in the previous year (HR=1.5, p=0.04). The association with the presence of gadolinium enhancement on MRI was not statistically significant. EDSS progression was only significantly associated with age at treatment start and treatment failure.

CONCLUSION

Our series demonstrates that some clinical and imaging factors are associated with treatment failure, and should be considered when planning treatment strategy in patients with recently diagnosed RR-MS.