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.

Efficacy of dalfampridine in neuromyelitis optica spectrum disorder: A pilot study.

Objective: To assess the efficacy of dalfampridine in patients with neuromyelitis optica spectrum disorder. Methods: We included 15 consecutive patients, who were started on a treatment of dalfampridine 10 mg twice daily for 2 weeks. Efficacy assessment was based on walking ability improvement using Timed-25-Foot Walk and 12-item Multiple Sclerosis Walking Scale tests. Results: The mean Timed-25-Foot Walk score was reduced from 14.8 (±2.4) to 11.3 (±1.9) seconds (p = 0.01). The mean score on the 12-item Multiple Sclerosis Walking Scale was reduced from 41.2 (±3.5) to 31.4 (±3.2) (p = 0.004). Conclusion: Dalfampridine seems to be useful for symptomatic treatment of walking impairment in neuromyelitis optica spectrum disorder.

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.

Cancer and multiple sclerosis: 2023 recommendations from the French Multiple Sclerosis Society.

BACKGROUND: Epidemiological data reveal that 45% of persons with multiple sclerosis (PwMS) in France are more than 50 years. This population more than 50 is more susceptible to cancer, and this risk may be increased by frequent use of immunosuppressive drugs. Consequently, concerns have arisen about the potential increased risk of cancer in PwMS and how patients should be screened and managed in terms of cancer risk. OBJECTIVE: To develop evidence-based recommendations to manage the coexistence of cancer and multiple sclerosis (MS). METHODS: The French Group for Recommendations in MS collected articles from PubMed and university databases covering the period January 1975 through June 2022. The RAND/UCLA method was employed to achieve formal consensus. MS experts comprehensively reviewed the full-text articles and developed the initial recommendations. A group of multidisciplinary health care specialists then validated the final proposal. RESULTS: Five key questions were addressed, encompassing various topics such as cancer screening before or after initiating a disease-modifying therapy (DMT), appropriate management of MS in the context of cancer, recommended follow-up for cancer in patients receiving a DMT, and the potential reintroduction of a DMT after initial cancer treatment. A strong consensus was reached for all 31 recommendations. CONCLUSION: These recommendations propose a strategic approach to managing cancer risk in PwMS.

Early use of high efficacy therapies in pediatric forms of relapsing-remitting multiple sclerosis: A real-life observational study.

BACKGROUND: Pediatric forms of multiple sclerosis are more active than those in adults. Yet, the effectiveness of different therapeutic approaches is not well studied in this population. Our objective was to compare the effectiveness of the early use of high efficacy therapies (HETs) with the effectiveness of moderate efficacy therapies (METs) in children with MS. METHODS: This observational study included patients diagnosed with pediatric MS, at 4 hospital centers in France, during a 10-year period. METs included: interferon ß-1a, glatiramer acetate, dimethyl fumarate, teriflunomide; HETs included: fingolimod, natalizumab, ocrelizumab, alemtuzumab. The primary endpoint was the occurrence of a new relapse, the secondary endpoint was EDSS worsening. RESULTS: Sixty-four patients were included in the analysis (80% women; mean age 15.5 years, 81% treated with MET) with a median follow-up of 22.5 months. At baseline, 52 patients were on MET (interferon ß-1a, glatiramer acetate, dimethyl fumarate, teriflunomide) and 12 patients were on HET (natalizumab, ocrelizumab). The cumulative probability of being relapse-free at 6.5 years was 23.3% on MET, vs 90.9% on HET (p = 0.013). The cumulative probability of no EDSS worsening did not differ between the 2 groups. CONCLUSION: Patients starting with METs had much higher clinical disease activity than those starting early with HETs. Rapid initiation of more aggressive treatment may allow better disease control; however, the data on EDSS worsening are not conclusive.

Clinical features and maternal and fetal outcomes in women with Guillain-Barré syndrome in pregnancy.

BACKGROUND: Guillain-Barre syndrome (GBS) is an acute inflammatory polyradiculoneuropathy rarely observed during pregnancy. METHODS: In this retrospective study, we analyzed the characteristics of pregnant women with GBS (pGBS) diagnosed in French University Hospitals in the 2002-2022 period and compared them with a reference group of same-age non-pregnant women with GBS (npGBS) identified in the same institutions & timeframe. RESULTS: We identified 16 pGBS cases. Median age was 31 years (28-36), and GBS developed in the 1st, 2nd, and 3rd trimester in 31%, 31% and 38% of cases respectively. A previous infection was identified in six cases (37%), GBS was demyelinating in nine cases (56%), and four patients (25%) needed respiratory assistance. Fifteen patients (94%) were treated with intravenous immunoglobulins, and neurological recovery was complete in all cases (100%). Unscheduled caesarean section was needed in five cases (31%), and two fetuses (12.5%) died because of cytomegalovirus (CMV) infection (1 case) and HELLP (Hemolysis, Elevated Liver enzymes and Low Platelets) syndrome (1 case). In comparison with a reference group of 18 npGBS women with a median age of 30 years (27-33), pGBS patients more frequently had CMV infection (31% vs 11%), had a prolonged delay between GBS onset and hospital admission (delay > 7 days: 57% vs 12%), more often needed ICU admission (56% vs 33%) and respiratory assistance (25% vs 11%), and more often presented with treatment-related fluctuations (37% vs 0%). CONCLUSIONS: This study shows GBS during pregnancy is a severe maternal condition with significant fetal mortality.

Real-World Effectiveness of Natalizumab Extended Interval Dosing in a French Cohort.

INTRODUCTION: Natalizumab, a therapy for relapsing-remitting multiple sclerosis (RRMS), is associated with a risk of progressive multifocal leukoencephalopathy (PML). Over the last several years, practitioners have used off-label extended interval dosing (EID) of natalizumab to reduce PML risk, despite the absence of a large-scale efficacy evaluation. METHODS: We conducted a retrospective, multicenter cohort study among adults with RRMS receiving stable standard interval dosing (SID), defined as a ≥ 12-month consecutive period of ≥ 11 natalizumab infusions/year in France. We compared the 12-month risk difference of remaining relapse-free (primary endpoint) between patients who switched to EID (≤ 9 natalizumab infusions) and those who remained on SID, with a noninferiority margin of - 11%. We used propensity score methods such as inverse probability treatment weighting (IPTW) and 1:1 propensity score matching (PSM). Secondary endpoints were annualized relapse rate, disease progression, and safety. RESULTS: Baseline characteristics were similar between patients receiving EID (n = 147) and SID (n = 156). The proportion of relapse-free patients 12 months postbaseline was 142/147 in the EID (96.6%) and 144/156 in the SID group (92.3%); risk difference (95% CI) 4.3% (- 1.3 to 9.8%); p < 0.001 for non-inferiority. There were no significant differences between relapse rates (0.043 vs. 0.083 per year, respectively; p = 0.14) or Expanded Disability Status Scale mean scores (2.43 vs. 2.72, respectively; p = 0.18); anti-JC virus index values were similar (p = 0.23); and no instances of PML were reported. The comparisons using IPTW (n = 306) and PSM (n = 204) were consistent. CONCLUSION: These results support the pertinence of using an EID strategy for RRMS patients treated with natalizumab. CLINICAL TRIALS: gov identifier (NCT04580381).

Pregnancy and multiple sclerosis: 2022 recommendations from the French multiple sclerosis society.

OBJECTIVE: The objective of this study was to develop evidence-based recommendations on pregnancy management for persons with multiple sclerosis (MS). BACKGROUND: MS typically affects young women in their childbearing years. Increasing evidence is available to inform questions raised by MS patients and health professionals about pregnancy issues. METHODS: The French Group for Recommendations in Multiple Sclerosis (France4MS) reviewed PubMed and university databases (January 1975 through June 2021). The RAND/UCLA appropriateness method was developed to synthesise the scientific literature and expert opinions on healthcare topics; it was used to reach a formal agreement. Fifty-six MS experts worked on the full-text review and initial wording of recommendations. A group of 62 multidisciplinary healthcare specialists validated the final proposal of summarised evidence. RESULTS: A strong agreement was reached for all 104 proposed recommendations. They cover diverse topics, such as pregnancy planning, follow-up during pregnancy and postpartum, delivery routes, locoregional analgesia or anaesthesia, prevention of postpartum relapses, breastfeeding, vaccinations, reproductive assistance, management of relapses and disease-modifying treatments. CONCLUSION: The 2022 recommendations of the French MS society should be helpful to harmonise counselling and treatment practice for pregnancy in persons with MS, allowing for better and individualised choices.

Kappa Free Light Chain Biomarkers Are Efficient for the Diagnosis of Multiple Sclerosis: A Large Multicenter Cohort Study.

BACKGROUND AND OBJECTIVES: Kappa free light chains (KFLC) seem to efficiently diagnose MS. However, extensive cohort studies are lacking to establish consensus cut-offs, notably to rule out non-MS autoimmune CNS disorders. Our objectives were to (1) determine diagnostic performances of CSF KFLC, KFLC index, and KFLC intrathecal fraction (IF) threshold values that allow us to separate MS from different CNS disorder control populations and compare them with oligoclonal bands' (OCB) performances and (2) to identify independent factors associated with KFLC quantification in MS. METHODS: We conducted a retrospective multicenter study involving 13 French MS centers. Patients were included if they had a noninfectious and nontumoral CNS disorder, eligible data concerning CSF and serum KFLC, albumin, and OCB. Patients were classified into 4 groups according to their diagnosis: MS, clinically isolated syndrome (CIS), other inflammatory CNS disorders (OIND), and noninflammatory CNS disorder controls (NINDC). RESULTS: One thousand six hundred twenty-one patients were analyzed (675 MS, 90 CIS, 297 OIND, and 559 NINDC). KFLC index and KFLC IF had similar performances in diagnosing MS from nonselected controls and OIND (p = 0.123 and p = 0.991 for area under the curve [AUC] comparisons) and performed better than CSF KFLC (p < 0.001 for all AUC comparisons). A KFLC index of 8.92 best separated MS/CIS from the entire nonselected control population, with better performances than OCB (p < 0.001 for AUC comparison). A KFLC index of 11.56 best separated MS from OIND, with similar performances than OCB (p = 0.065). In the multivariate analysis model, female gender (p = 0.003), young age (p = 0.013), and evidence of disease activity (p < 0.001) were independent factors associated with high KFLC index values in patients with MS, whereas MS phenotype, immune-modifying treatment use at sampling, and the FLC analyzer type did not influence KFLC index. DISCUSSION: KFLC biomarkers are efficient tools to separate patients with MS from controls, even when compared with other patients with CNS autoimmune disorder. Given these results, we suggest using KFLC index or KFLC IF as a criterion to diagnose MS. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that KFLC index or IF can be used to differentiate patients with MS from nonselected controls and from patients with other autoimmune CNS disorders.

Pregnancy and neuromyelitis optica spectrum disorders: 2022 recommendations from the French Multiple Sclerosis Society.

BACKGROUND: In 2020, the French Multiple Sclerosis (MS) Society (SFSEP) decided to develop a national evidence-based consensus on pregnancy in MS. As neuromyelitis optica spectrum disorders (NMOSD) shares a series of commonalities with MS, but also some significant differences, specific recommendations had to be developed. OBJECTIVES: To establish recommendations on pregnancy in women with NMOSD. METHODS: The French Group for Recommendations in Multiple Sclerosis (France4MS) reviewed PubMed and universities databases (January 1975 through June 2021). The RAND/UCLA appropriateness method, which was developed to synthesise the scientific literature and expert opinions on health care topics, was used to reach a formal agreement. Fifty-six MS experts worked on the full-text review and initial wording of recommendations. A sub-group of nine NMOSD experts was dedicated to analysing available data on NMOSD. A group of 62 multidisciplinary healthcare specialists validated the final proposal of summarised evidence. RESULTS: A strong agreement was reached for all 66 proposed recommendations. They cover diverse topics, such as pregnancy planning, follow-up during pregnancy and postpartum, delivery routes, loco-regional analgesia or anaesthesia, prevention of postpartum relapses, breastfeeding, vaccinations, reproductive assistance, management of relapses, and disease-modifying treatments. CONCLUSION: Physicians and patients should be aware of the new and specific evidence-based recommendations of the French MS Society for pregnancy in women with NMOSD. They should help harmonise counselling and treatment practise, allowing for better individualised choices.

The Translatability of Multiple Sclerosis Animal Models for Biomarkers Discovery and Their Clinical Use.

Multiple Sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system which is characterized by demyelinating lesions and axonal damage. MS is a complex disease characterized by important pathophysiological heterogeneity affecting the clinical appearance, progression and therapeutic response for each patient. Therefore, there is a strong unmet need to define specific biomarkers that will reflect the different features of the disease. Experimental autoimmune encephalomyelitis (EAE) is the most commonly used experimental model for the study of MS, as it resembles the pathological features of human MS in many aspects and has allowed for the elucidation of pathogenesis pathways and the validation of certain targets for MS therapies. In this review, we discuss clinically relevant MS molecular biomarkers, divided into five groups based on the key pathological hallmarks of MS: inflammation, blood-brain barrier disruption, myelin and axonal damage, gliosis and, ultimately, repair mechanisms. To address the feasibility of translation between the animal model and human disease, we present an overview of several molecular biomarkers of each category and compare their respective deregulation patterns. We conclude that, like any disease animal model, EAE models can sometimes fail to mimic the entire spectrum of human disease, but they can nonetheless recapitulate the disease's primary hallmarks. We show that the EAE model is a valuable tool for understanding MS physiopathological mechanisms and for identifying biomarkers fundamental for drug development.

Anti-CD20 immunotherapy in progressive multiple sclerosis: 2-year real-world follow-up of 108 patients.

BACKGROUND: Anti-CD20 monoclonal antibodies are recently introduced treatments in progressive MS and real-world data are lacking. OBJECTIVE: The aim of this study is to describe a cohort of progressive MS patients treated with ocrelizumab or rituximab in a real-world setting. METHODS: This monocentric prospective cohort study at the University Hospital of Strasbourg included patients with primary progressive or secondary progressive MS that started treatment with anti-CD20 antibodies before June 2019. Every six months, patients were assessed using the following standardized clinical evaluations: Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9-HPT) and Symbol Digit Modalities Test (SDMT). The primary analysis considered EDSS progression (of at least 1.0 if EDSS ≤ 5.5 and at least 0.5 if EDSS ≥ 6.0). RESULTS: We included 108 patients, with a median age upon inclusion of 53 years [48.0-58.0]. 72% were classified as primary progressive forms. Median baseline EDSS was 6.0 [4.0-6.5]. EDSS was significantly correlated with T25FW, SDMT and 9-HPT. Following 2 years of treatment, 38.9% of patients presented EDSS progression compared to baseline. CONCLUSION: Our large cohort confirms tolerance of these treatments in a real-world setting. Standardized clinical assessments could improve detection of deteriorating patients. Further studies are needed to establish predictive factors.

Ocrelizumab versus fingolimod after natalizumab cessation in multiple sclerosis: an observational study.

BACKGROUND: Exit strategy after natalizumab cessation in multiple sclerosis (MS) is a crucial point because the risk of disease reactivation is high during this period. The objective of this observational study was to compare ocrelizumab to fingolimod after natalizumab cessation in patients with relapsing-remitting multiple sclerosis (RRMS). METHODS: All RRMS patients starting fingolimod or ocrelizumab within 6 weeks after natalizumab cessation were included. The primary endpoint was the annualized relapse rate (ARR) at 1 year. RESULTS: We included 54 patients receiving fingolimod and 48 patients receiving ocrelizumab after natalizumab cessation. In multivariate analysis, ARR at 1 year was significantly lower in the ocrelizumab group than in the fingolimod group (0.12 ± 0.39 versus 0.41 ± 0.71, p = 0.026), i.e. a 70.7% lower relapse rate. The cumulative probability of relapses at 1 year was 31.5% (17/54 patients) with fingolimod and 10.4% (5/48 patients) with ocrelizumab, corresponding to a hazard ratio of 3.4 (95% confidence interval: 1.1-11, p = 0.04). CONCLUSIONS: Our results suggest ocrelizumab is potentially a better exit strategy than fingolimod after natalizumab cessation.

A rise in cases of nitrous oxide abuse: neurological complications and biological findings.

BACKGROUND: The recent lockdown due to the COVID-19 pandemic has been linked to a higher incidence of psychiatric manifestations and substance abuse. The recreative use of nitrous oxide is more and more widespread and neurological complications are frequent. METHODS: We report clinical characteristics and biological findings of five consecutive patients presenting to our tertiary care center between April 2020 and February 2021 with various neurological symptoms occurring after recent nitrous oxide abuse. RESULTS: Our patients presented with subacute combined degeneration of the spinal cord (4/5 patients) or with acute inflammatory demyelinating polyneuropathy (1/5 patients). No patient had reduced vitamin B-12 titer, but all had elevated blood levels of homocysteine and methylmalonic acid. This reflects the functional deficit in vitamin B-12 that can be linked to nitrous oxide consumption. After vitamin B-12 supplementation, clinical signs regressed at least partially in all 5 patients. CONCLUSION: We report an elevated incidence of neurological complications of nitrous oxide abuse occurring during the recent COVID-19 lockdown. Nitrous oxide abuse should be tracked down in patients presenting with compatible neurological symptoms and elevated homocysteinemia. Vitamin B-12 should be supplemented as soon as the diagnosis is made.

A multicenter cross-sectional French study of the impact of COVID-19 on neuromuscular diseases.

BACKGROUND: Due to their health condition, patients with neuromuscular diseases (NMD) are at greater risk of developing serious complications with COVID-19. The objective of this study was to analyze the prevalence of COVID-19 among NMD patients and the risk factors for its impact and severity during the first wave of the pandemic. Clinical data were collected from NMD-COVID-19 patients, between March 25, 2020 and May 11, 2020 in an anonymous survey carried out by expert physicians from the French Health Care Network Filnemus. RESULTS: Physicians reported 84 patients, including: 34 with myasthenia gravis, 27 with myopathy and 23 with neuropathy. COVID-19 had no effect on NMD for 48 (58%) patients and 48 (58%) patients developed low COVID-19 severity. COVID-19 caused the death of 9 (11%) NMD patients. Diabetic patients were at greater risk of dying. Patients with diabetes, hypertension or severe forms of NMD had a higher risk of developing a moderate or severe form of COVID-19. In our cohort, corticosteroids and other immunosuppressants were not significantly associated with higher COVID-19 severity for acquired NMD. CONCLUSION: During this period, a small percentage of French NMD patients was affected by COVID-19 compared to the general French population and COVID-19 had a limited short-term effect on them. Diabetes, hypertension and a severe degree of NMD were identified as risk factors of unfavorable outcome following COVID-19. Conversely, in our cohort of patients with acquired NMD, corticosteroids or other immunosuppressants did not appear to be risk factors for more severe COVID-19.

Impact of Disease-Modifying Treatments of Multiple Sclerosis on Anti-SARS-CoV-2 Antibodies: An Observational Study.

OBJECTIVE: To compare the humoral response after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with multiple sclerosis (MS) receiving different disease-modifying treatments (DMTs). METHODS: Patients with MS with coronavirus disease 2019 (COVID-19) and available anti-SARS-CoV-2 serology were included. The primary endpoint was the anti-SARS-CoV-2 immunoglobulin G (IgG) index. The multivariate analysis was adjusted for COVID-19 severity, SARS-CoV-2 PCR result, and the time between COVID-19 onset and the serology. RESULTS: We included 61 patients with available IgG index. The IgG index was lower in patients with fingolimod or anti-CD20 monoclonal antibodies compared with patients without treatment (p < 0.01), patients with interferon ß-1a or glatiramer (p < 0.01), and patients with another DMT (p = 0.01). The IgG index was correlated with the time between COVID-19 onset and serology (r = -0.296 [-0.510; -0.0477], p = 0.02). CONCLUSIONS: Humoral response after COVID-19 was lower in patients with MS with fingolimod or anti-CD20 mAb. These patients could therefore be at risk of recurrent infection and could benefit from anti-SARS-CoV-2 vaccination. The humoral response after vaccination and the delay before vaccination need to be evaluated. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that patients treated with fingolimod or anti-CD20 monoclonal antibodies for MS have a lower humoral response after COVID-19 compared with patients without DMTs or with another DMTs.

How to switch disease-modifying treatments in multiple sclerosis: Guidelines from the French Multiple Sclerosis Society (SFSEP).

BACKGROUND: Today, there are no recommendations on switching disease-modifying treatments (DMTs) in multiple sclerosis (MS). OBJECTIVES: To establish guidelines on switching DMTs MS. METHODS: A Steering Committee composed of seven MS experts from the French Group for Recommendations in Multiple Sclerosis (France4MS) defined 15 proposals. These proposals were then submitted to a Rating Group, composed of 48 French MS experts, for evaluation. The proposals were classified as 'appropriate', 'inappropriate' or 'uncertain'. RESULTS: Switching from a first-line therapy to another first-line therapy or a second-line therapy could be done without a washout period. Switching from a second-line therapy to a first-line therapy could be done without a washout period with fingolimod or natalizumab, after 3 months with ocrelizumab or mitoxantrone, and, if disease activity occurs with alemtuzumab or cladribine. The switch from a second-line therapy to another second-line therapy could be done after a washout period of 1 month with fingolimod or natalizumab, after 3 months with ocrelizumab, after 6 months with mitoxantrone, and, if disease activity occurs, with alemtuzumab or cladribine. CONCLUSION: This expert consensus approach provides physicians with some guidelines on optimizing the benefit/risk ratio when switching DMTs in patients with MS.

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.