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Background: Two-stage models of heterogenous treatment effects (HTE) may advance personalized medicine in multiple sclerosis (MS). Brain atrophy is a relatively objective outcome measure that has strong relationships to MS prognosis and treatment effects and is enabled by standardized MRI., Objectives: To predict brain atrophy outcomes for patients initiating disease-modifying therapies (DMT) with different efficacies, considering the patients' baseline brain atrophy risk measured via brain parenchymal fraction (BPF)., Methods: Analyses included patients enrolled in the Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS) network who started DMT and had complete baseline data and ≥ 6-month brain MRI follow-up. All brain MRIs were acquired using standardized acquisition sequences on Siemens 3T scanners. BPF change risk was derived by linear mixed effects models using baseline covariates. Model performance was assessed by predicted versus actual BPF change R 2 . Propensity score (PS) weighting was used to balance covariates between groups defined by DMT efficacy (high: natalizumab, alemtuzumab, ocrelizumab, and rituximab; moderate: dimethyl fumarate, fingolimod, and cladribine; low: teriflunomide, interferons, and glatiramer acetate). HTE models predicting 1 year change in BPF were built using a weighted linear mixed effects model with low-efficacy DMT as the reference., Results: Analyses included 581 high-, 183 moderate-, and 106 low-efficacy DMT-treated patients. The mean and median number of brain MRI observations per treatment period were 2.9 and 3.0, respectively. Risk model performance R 2 =0.55. After PS weighting, covariate standardized mean differences were <10 %, indicating excellent balance across measured variables. Changes in BPF between baseline and follow-up were found to be statistically significant (p < 0.001), suggesting a pathological change. Patients with low brain atrophy risk had a similar outcome regardless of DMT selection. In patients with high brain atrophy risk, high- and moderate-efficacy DMTs performed similarly, while a 2-fold worse BPF change was predicted for patients selecting low-efficacy DMTs (p < 0.001). Similar results were observed in a sensitivity analysis adjusting for pseudoatrophy effects in a sub-population of patients treated with natalizumab., Conclusions: The relative benefit of selecting higher efficacy treatments may vary depending on patients' baseline brain atrophy risk. Poor outcomes are predicted in individuals with high baseline risk who are treated with low-efficacy DMTs., Competing Interests: Declaration of competing interest The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Carrie M. Hersh has received speaker, consulting, and/or advisory board fees from Biogen, Novartis, Bristol-Meyers Squibb, EMD Serono, Genentech, Genzyme, TG Therapeutics, Alexion Pharmaceuticals, and Horizon Therapeutics; she also receives research paid directly to her institution from Biogen, Novartis, Bristol Meyers-Squibb, NIHNINDS 1U01NS111678–01A1 sub-award, and Patient Centered Outcomes Research Institute. Zhaonan Sun is an employee of Biogen and may own stock in Biogen at the time this analysis was conducted. Devon Conway, MD has received research support paid to his institution from Novartis, EMD Serono, Horizon Therapeutics, Biogen, Bristol Meyers Squibb, and the Department of Defense. He has received consulting fees from Novartis, Bristol Myers Squibb, TG Therapeutics, and Arena Pharmaceuticals and speaking fees from Biogen. Elias Sotirchos has consulted for Alexion, Horizon Therapeutics, TG Therapeutics, and Roche/Genentech, and has received speaking honoraria from Alexion and Biogen. Kathryn C. Fitzgerald has no conflicts of interest to disclose. Le H. Hua has served as a consultant to Genentech, Novartis, EMD Serono, TG Therapeutics, Horizon, and Alexion; on scientific advisory boards for Genentech, EMD Serono and Novartis; and has received non-promotional speaker honoraria for Genzyme and TG Therapeutics. She has received research funding paid directly to her institution from Biogen. Tjalf Ziemssen received grants and study funding as well as speaking and consulting fees from Biogen, BMS, Hexal, Merck, Novartis, Roche, Sanofi, TEVA and Viatris. Robert T. Naismith has consulted for Alexion Pharmaceuticals, Biogen, Bristol Myers Squibb, Celltrion, Genentech, Genzyme, EMD Serono, Horizon Therapeutics, Novartis, TG Therapeutics. Fabio Pellegrini was an employee of Biogen and may own stock in Biogen at the time this analysis was conducted. Cynthia Grossman was an employee of Biogen and may own stock in Biogen at the time this analysis was conducted. Nolan Campbell was an employee of Biogen and may own stock in Biogen at the time this analysis was conducted., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: The non-inferiority of the efficacy of subcutaneous (SC) vs intravenous (IV) administration of natalizumab (NTZ) once every 4 weeks in relapsing-remitting multiple sclerosis (RRMS) was recently demonstrated on the primary outcome of the REFINE study, i.e. MRI "combined unique active lesions number" (CUAL). To provide further evidence on the comparative efficacy of the two NTZ formulations, the effect of NTZ-SC vs NTZ-IV on annualized relapse rate (ARR) was investigated re-analysing the REFINE dataset., Methods: Post-hoc analysis of the REFINE study dataset aimed at exploring the non-inferiority of the efficacy of NTZ-SC vs NTZ-IV on ARR, i.e. the main secondary outcome of the REFINE study. Robustness of the non-inferiority analysis on CUAL with respect to the presence of cases from the SC arm who received a rescue treatment, including NTZ-IV, was also assessed by sensitivity analyses. Three non-inferiority margins were selected, corresponding to 25 %, 33 %, and 50 % fractions of the effect size of NTZ-IV vs placebo observed in the AFFIRM study on ARR (i.e. 0.125, 0.170, and 0.250)., Results: Ninety-nine RRMS patients were included. The mean difference in the effect of NTZ-SC vs NTZ-IV on ARR was close to 0. The lower bound of the 95 % confidence interval (worst case scenario) was -0.119, corresponding to 25 % (p = 0.025) of the effect of NTZ-IV vs placebo on ARR. Sensitivity analyses confirmed the results of the primary non-inferiority analysis on the outcome CUAL., Conclusions: NTZ-SC resulted not inferior to NTZ-IV on ARR for all the non-inferiority margins. The non-inferiority analysis of the efficacy of NTZ-SC vs NTZ-IV on CUAL was demonstrated to be robust with respect to rescued patients., Competing Interests: Declaration of competing interest A.Mar. reports speaking honoraria from Sanofi, Biogen, Janssen, Novartis and Viatris; non-financial support from Biogen, Novartis, Janssen, and Sanofi, outside the submitted work. F.M. discloses consulting honoraria from Novartis and Daiichi-Sankyohas. A.Mat. has no competing interests to declare that are relevant to the content of this article. L.M. reports non-financial support and speaker honoraria from Biogen, Novartis, Merck Serono, Genzyme and Teva, Viatris., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Several studies reported lower drug concentrations with subcutaneous natalizumab compared to intravenous natalizumab. With the emergence of extended interval dosing, gaining more insight into lower concentrations after subcutaneous administration is essential., Methods: We compared serum trough concentrations between subcutaneous and intravenous administration within a matched cohort (n = 50)., Results: Subcutaneous administration (n = 25) was associated with lower concentrations compared to intravenous administration (n = 25) (log-B=-0.28, p = 0.01). In an exploratory group of 11 patients receiving extended interval dosing of subcutaneous natalizumab, the median trough concentration was even lower., Conclusion: Subcutaneous natalizumab can lead to lower drug concentrations, potentially limiting extended interval dosing., Competing Interests: Declaration of competing interest L.M.Y.G. had nothing to disclose. S.L. has nothing to disclose. A.A.T. has nothing to disclose. J.H. has nothing to disclose. F.C.L. has nothing to disclose. T.R. has received funding for research from Genmab; received consulting fees from Novartis. J.K. has received research grants for multicentre investigator initiated trials DOT-MS trial, ClinicalTrials.gov Identifier: NCT04260711 (ZonMW) and BLOOMS trial (ZonMW and Treatmeds), ClinicalTrials.gov Identifier: NCT05296161); received consulting fees for F. Hoffmann-La Roche Ltd, Biogen, Teva, Merck, Novartis and Sanofi/Genzyme (all payments to institution); reports speaker relationships with F. Hoffmann-La Roche Ltd, Biogen, Immunic, Teva, Merck, Novartis and Sanofi/Genzyme (all payments to institution); adjudication committee of MS clinical trials of Immunic (payments to institution only). E.C.T. has received honorarium for consulting work from Biogen, Janssen, Merck, Novartis, and Roche. She has received travel grants to attend or speak at educational meetings from Biogen, Merck, Roche and Novartis. Z.L.E.v.K. has nothing to disclose., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background and Objectives: Although pediatric-onset multiple sclerosis (POMS) is characterized by a more rapid accumulation of CNS inflammation than adult-onset MS (AOMS), the therapeutic algorithms applied in POMS are usually based on AOMS therapeutic outcomes. To define a high-efficacy treatment (HET)-based strategy to treat POMS, we designed an observational retrospective study aimed at evaluating the efficacy and safety of natalizumab (NTZ) in naïve POMS and AOMS., Methods: Starting from 160 patients, we applied a 2:1 (adult:pediatric) matching on propensity scores and obtained 32 patients with NTZ-treated POMS and 64 with AOMS, estimated from a multivariable logistic regression model. All patients were clinically and radiologically followed up every 6 months for a mean period of 46.0 ± 26.9 months., Results: Following re-baseline at month 6, no difference (log-rank test: p = 0.924) in new and enlarging T2 white matter lesions, postcontrast T1 lesions, and relapse rate were observed between POMS and AOMS throughout the study. Progression independent of relapse activity (PIRA) was never observed in POMS, while 9 of 64 patients with AOMS (12.5%) had PIRA events during the follow-up (40.0 ± 25.9 months; log-rank p value 0.0156). JCV seroconversion rate during NTZ infusion did not differ between POMS and AOMS (log-rank test p = 0.3231). Finally, no serious adverse event was observed in both POMS and AOMS., Discussion: The favorable outcomes observed on clinical, especially in PIRA, and radiologic parameters strongly support the use of NTZ as a first-choice HET in POMS.

Background: Neurofilament light chain (NFL) is a biomarker for monitoring disease activity and treatment response in multiple sclerosis (MS). However, while most agree that NFL levels predict disease activity and worsening, the predictive value of NFL on future relapse risk remains uncertain., Objective: The primary aim was to evaluate the predictive value of age-corrected serum NFL (sNFL) ratio on relapse risk in highly active relapsing-remitting MS patients (RRMS) treated with natalizumab. A secondary aim was to investigate the predictive value of sNFL ratios for MRI activity., Methods: From January 1, 2006, to December 31, 2010, 355 patients initiated natalizumab treatment at the Danish Multiple Sclerosis Center. 305 patients were anti-natalizumab antibodies negative and had at least one blood sample available for sNFL analysis using single molecule array analysis at baseline, three, six, or 12 months. The patients were either treatment-naïve (n = 8), switching from interferon-β or glatiramer acetate (n = 253), or switching from mitoxantrone (n = 44). An age-corrected ratio was calculated for sNFL. Time to first relapse was calculated from baseline and after re-baseline at 90 days. Data were collected from baseline until the two-year follow-up or end of treatment and included disease duration, expanded disability status scale, previous treatments, relapses 12 months prior to natalizumab initiation, smoking intensity, body mass index, and body weight. In addition, the patients underwent annual MRI of the brain., Results: The sNFL ratio was increased in 173 of 287 samples (60.3 %) at baseline, in 119 of 246 samples (48.8 %) at month three, in 109 of 287 samples (38.0 %) at month six, and in 82 of 270 samples (30.4 %) at month 12. The sNFL ratio continuously declined over 12 months with significant decreases for every measuring timepoint: baseline vs. three months p = 3.0 × 10 -6 ; three months vs. six months p = 3.2 × 10 -5 ; six months vs. 12 months p = 0.002. Univariate Cox regression analysis showed that time to first relapse from 1) natalizumab initiation and from 2) re-baseline was associated with the number of relapses in the previous 12 months (hazard ratio 1.31 per relapse, 95 % CI = 1.2-1.5, p = 2.0 × 10 -6 ; and 1.21 per relapse, 95 % CI = 1.1-1.4, p = 0.002, respectively). sNFL ratio at re-baseline was negatively associated with relapse risk (hazard ratio 0.82 per unit; 95 % CI = 0.7-1.0; p = 0.049). A multivariable Cox regression analysis of relapse risk from re-baseline showed that the number of relapses in the 12 months prior to natalizumab treatment (hazard ratio 1.29; 95 % CI = 1.1-1.5; p = 6.0 × 10 -4 ) and smoking (hazard ratio 1.51 per 20 cigarettes per day; 95 % CI = 1.0-2.2; p = 0.030) were associated with increased risk of relapse; sNFL ratio was associated with a lower risk of relapse (hazard ratio = 0.736 per unit; 95 % CI = 0.6-0.9 p = 0.007). In univariate logistic regression analyses, the sNFL ratio at 12 months and values above the 75th and the 90th percentile predicted MRI activity in the following year (odds ratio [OR] = 2.0, 95 % CI = 1.2-3.6, p = 0.012; OR = 2.2, 95 % CI = 1.2-4.1, p = 0.014; and OR = 2.8, 95 % CI = 1.1-6.7, p = 0.026)., Conclusion: In this highly active RRMS cohort, high sNFL ratios reflected previous relapse activity and decreased after initiation of treatment but were not associated with increased relapse risk in the following two years. Pre-treatment relapses and smoking on treatment were predictors of relapse risk after re-baselining at 90 days. MRI activity in year two was predicted by sNFL ratios at month 12., Competing Interests: Declaration of competing interest H. Højsgaard Chow reports non-financial support from Merck, non-financial support from Teva, non-financial support from Biogen, non-financial support from Roche, outside the submitted work and personal support from the Warwara Larsen Foundation. E. Rosa Petersen has nothing to declare. A. Olsson has nothing to declare. J. Hejgaard Laursen has nothing to declare. M. Bredahl Hansen has nothing to declare. A. Bang Oturai has nothing to declare. P. Soelberg Sørensen has received personal compensation for consultations, serving on scientific advisory boards, steering committees, independent data monitoring committees or have received honoraria as speaker from Biogen, Merck, Novartis, TEVA, and BMS/Celgene. H. Bach Søndergaard has nothing to declare. F. Sellebjerg reports grants from Biogen, grants from Danish Multiple Sclerosis Society, during the conduct of the study; grants and personal fees from Biogen, personal fees from Lundbeck, grants and personal fees from Merck, grants and personal fees from Novartis, grants and personal fees from Roche, grants and personal fees from Sanofi Genzyme, outside the submitted work; and Professor F. Sellebjerg is section editor on Multiple Sclerosis and Related Disorders., (Copyright © 2024. Published by Elsevier B.V.)

Background: Multiple Sclerosis (MS) a central nervous system autoimmune disorder, mainly affecting young adults and more prevalent among women, can lead to sexual dysfunction (SD) among both males and females with MS. Female sexual dysfunction can be defined as dyspareunia, a lack of sexual desire, disorders in the arousal and orgasm phases, and sexual pain disorders. The purpose of this study is to investigate the changes in sexual function among females with MS whose treatment was switched from first-line injectable medications to other agents after a six-month duration. And assess the changes in all three domains of SD., Methods: In this longitudinal study females diagnosed with MS, aged between 18 and 50 years old, and were candidates for switching their treatment from interferon beta-1a (intra-muscular and subcutaneous), and Glatiramer Acetate (GA), to Fingolimod, Dimethyl Fumarate (DMF), or Natalizumab (NTZ) due to patients' convenience and tolerability and adverse events were included. "Multiple Sclerosis Intimacy and Sexuality Questionnaire-19" was used to evaluate the SD changes before and six months after the new treatment initiation. Statistical analysis was conducted using SPSS V.24 software. Histograms and the Shapiro-Wilk test were used to assess the normality of the variables; due to the non-normal distribution of quantitative variables (except for age), the Wilcoxon signed-rank test was used to compare the scores, before and six months after the medication change. The level of significance was considered less than 0.05., Results: Out of 107 female participants (average age: 35.09 ± 5.61), The mean of overall MSISQ-19 scores, before and six months after the medication change were not significant (p-value = 0.091). However, considering the subdomains, the medication changes only affected the tertiary subdomain of MSISQ-19 (p-value = 0.017). Still, the scores of other subdomains did not change significantly (p-value = 0.761 for primary SD and 0.479 for secondary SD). Also, there wasn't any significant difference between EDSS before and after the medication change (p-value = 0.461)., Conclusions: To our knowledge, this was the first study, assessing the effect of MS medication change on the improvement of SD among patients. According to the results of the presented cross-sectional study, we found that during a six-month period, the tertiary subdomain of MSISQ-19 symptoms improved significantly, while the changes in other SD domains were not significant., (© 2024. The Author(s).)

Background and Objectives: Wearing-off symptoms during natalizumab treatment in multiple sclerosis are characterized by an increase of MS-related symptoms prior to natalizumab administration. The influence of extended interval dosing (EID) on wearing-off symptoms are important to consider, as this might cause hesitancy in initiating or continuing EID., Methods: Participants of the NEXT-MS trial, in which treatment intervals are adjusted based on drug concentrations, were divided into two groups: an extended group containing participants with at least one week of additional interval extension, and a group with a fixed interval during the trial (range 4-7 weeks). Changes in the occurrence, frequency, onset, and severity of wearing-off symptoms were evaluated., Results: 255 participants were included (extended group n = 171, fixed group n = 84). The odds on occurrence of wearing-off symptoms in the extended group did not increase after extending the treatment interval. Additional analyses for frequency, onset, and severity of wearing-off symptoms showed no changes over time. Mean decrease in natalizumab drug concentration did not influence the frequency of wearing-off symptoms., Discussion: Wearing-off symptoms were not reinforced by further extending the natalizumab interval. Wearing-off symptoms might increase in a minority of patients after EID, although our data support the view that wearing-off symptoms appear to be unrelated to the decrease in natalizumab trough drug concentrations., Competing Interests: Declaration of competing interest A.A. Toorop: nothing to disclose. M.H.J. Wessels: nothing to disclose. L.M.Y. Gelissen: nothing to disclose. E. Hoitsma: has accepted (speaker and congress) fees from Merck Serono, Biogen Idec, Roche, and Sanofi Genzyme. E.M.P.E. Zeinstra: reports advisory boards/consultancy fees for Merck, Novartis, Genzyme and Roche. L.C. van Rooij: nothing to disclose. C.E.P. van Munster: nothing to disclose. A. Vennegoor: nothing to disclose. J.P. Mostert: nothing to disclose. B.H.A. Wokke: nothing to disclose. N.F. Kalkers: nothing to disclose. E.L.J. Hoogervorst: nothing to disclose. J.J.J. van Eijk: reports honoraria for advisory boards and/or speakers fee from Merck Serono, Biogen Idec, Sanofi Genzyme, Roche and Novartis. C.M. Roosendaal: nothing to disclose. J.J. Kragt: nothing to disclose. M. Eurelings: nothing to disclose. J. Nielsen: nothing to disclose. J. van Genugten: nothing to disclose. L.G.F. Sinnige: nothing to disclose. M.E. Kloosterziel: nothing to disclose. E.P.J. Arnoldus: nothing to disclose. G.W. van Dijk: nothing to disclose. W.H. Bouvy: nothing to disclose. E.M.M. Strijbis: nothing to disclose. B.W. van Oosten: nothing to disclose. B.A. de Jong: nothing to disclose. B.I. Lissenberg-Witte: nothing to disclose. T. Rispens received funding for research from Genmab and consultancy fees from Novartis. B.M.J. Uitdehaag: reports research support and/or consultancy fees from Genzyme, Biogen Idec, Novartis, Teva Pharmaceutical Industries, Merck Serono, Roche, and Immunic Therapeutics. J. Killestein: received research grants for multicentre investigator initiated trials DOT-MS trial, ClinicalTrials.gov Identifier: NCT04260711 (ZonMW) and BLOOMS trial (ZonMW and Treatmeds), ClinicalTrials.gov Identifier: NCT05296161); received consulting fees for F. Hoffmann-La Roche Ltd., Biogen, Teva, Merck, Novartis and Sanofi/Genzyme (all payments to institution); reports speaker relationships with F. Hoffmann-La Roche Ltd., Biogen, Immunic, Teva, Merck, Novartis and Sanofi/Genzyme (all payments to institution); adjudication committee of MS clinical trial of Immunic (payments to institution only). Z.L.E. van Kempen: nothing to disclose., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Natalizumab (NAT) pharmacokinetics and pharmacodynamics are complicated by arm exchange with endogenous IgG4, resulting in a mixture of a more potent intact, bivalent form and a less potent, functionally monovalent form. Total NAT and endogenous IgG4 concentrations vary considerably across patients. This study assessed the concentration of intact NAT, and how it relates to total NAT and endogenous IgG4 levels in blood and saliva., Methods: Paired serum and saliva samples from a small cohort of relapsing-remitting multiple sclerosis patients were measured for levels of intact NAT, total NAT, IgG and IgG4., Results: Intact NAT concentration was dependent on both total NAT and endogenous IgG4 levels. Low endogenous IgG4 led to a higher ratio of intact NAT to total NAT, while the opposite was observed in subjects with high endogenous IgG4. Serum and saliva measurements show good concordance., Conclusions: Intact NAT concentration is influenced by both NAT pharmacokinetics and endogenous IgG4 levels. Patients with low IgG4 levels can have high concentrations of intact NAT even with lower levels of total NAT, which may explain cases of NAT-associated progressive multifocal leukoencephalopathy (PML) in such patients. Monitoring both forms of NAT could better guide dosing, maximizing drug efficacy and safety., Competing Interests: Declaration of competing interest At the time of writing, Dr. Bradley Messmer was CSO of Aegirbio AB and received stock compensation from Aegirbio AB. J. Foley has received research support from Biogen, Octave, and Genentech. He received speakers' honoraria from Biogen. He has participated in advisory boards for Biogen, Horizon, Sandoz, and TG Therapeutics. He is the founder of InterPro Biosciences. L.J.P, I.F.P, R.H, T.H and E.T.C report no conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

To quantify the probability that monthly intravenous (IV) and subcutaneous (SC) natalizumab (NTZ) had similar efficacy in relapsing-remitting multiple sclerosis (RRMS), non-inferiority of efficacy of NTZ-SC versus NTZ-IV on combined MRI unique active lesions number (CUAL) was explored re-analysing the REFINE data set. Non-inferiority margins were selected equal to 25%/33%/50% fractions of the effect size of NTZ-IV versus placebo observed in the AFFIRM study. Ninety-nine RRMS were included. NTZ-SC resulted not inferior to NTZ-IV on CUAL for all margins at 2.5% significance level, and, in worst-case scenario, its effect over NTZ-IV did not exceed 3.5% (or 2.8%) of the effect of NTZ-IV versus placebo., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship and/or publication of this article: F.M. discloses consulting honoraria from Novartis and Daiichi-Sankyohas. A.Mat. has no competing interests to declare that are relevant to the content of this article. A.Mar. reports speaking honoraria from Sanofi, Biogen, Janssen and Novartis; non-financial support from Biogen, Novartis, Janssen and Sanofi, outside the submitted work. L.M. reports non-financial support and speaker honoraria from Biogen, Novartis, Merck Serono, Genzyme and Teva and Viatris.

Background: in the early stages of Multiple Sclerosis (MS), initiating high-efficacy disease-modifying therapy (HE DMTs) may represent an optimal strategy for delaying neurological damage and long-term disease progression, especially in highly active MS patients (HAMS). Natalizumab (NAT) and Ocrelizumab (OCR) are recognized as HE DMTs with significant anti-inflammatory effects. This study investigates NEDA-3 achievement in treatment-naïve HAMS patients receiving NAT or OCR over three years., Methods: we retrospectively enrolled treatment-naïve HAMS patients undergoing NAT or OCR, collecting demographic, clinical, and instrumental data before and after treatment initiation to compare with propensity score analysis disease activity, time to disability worsening, and NEDA-3 achievement., Results: we recruited 281 HAMS patients with a mean age of 32.7 years (SD 10.33), treated with NAT (157) or OCR (124). After three years, the Kaplan-Meier probability of achieving NEDA-3 was 66.0 % (95 % CI: 57.3 % - 76.0 %) with OCR and 68.2 % (95 % CI: 59.9 % - 77.7 %) with NAT without significant differences between the two groups (p = 0.27) DISCUSSION AND CONCLUSION: starting HE DMT with monoclonal antibodies for HAMS could achieve NEDA-3 in a high percentage of patients without differences between NAT or OCR., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Irene Schiavetti reports a relationship with Roche, Biogen, Horizon, Novartis, Hoya, Hippocrates Research, D.M.G Italia, Eyepharma, DreamsLab that includes: consulting or advisory. Livia Pasquali reports a relationship with Alexion, Biogen, Sanofi, Merck, Novartis, Roche that includes: consulting or advisory and travel reimbursement. Elisabetta Signoriello reports a relationship with Almirall, Biogen, Genzyme, Novartis, Teva that includes: board membership and travel reimbursement. Maria Pia Sormani reports a relationship with Biogen Idec, Merck Serono, Teva, Genzyme, Roche, Novartis, GeNeuro, Medday that includes: consulting or advisory. Jessica Frau reports a relationship with Biogen, Bristol, Novartis, Genzyme, Merck, Teva, Alexion that includes: board membership, consulting or advisory, and speaking and lecture fees. Daniele Caliendo reports a relationship with Merck that includes: funding grants. Alessio Signori reports a relationship with Roche, Horizon, Novartis that includes: speaking and lecture fees. Andrea Surcinelli reports a relationship with Roche, Merck, Biogen, Sanofi, Novartis that includes: travel reimbursement. Simona Bonavita reports a relationship with Novartis, Merck-Serono, Alexion, BMS, Biogen, Roche, Janssen-Cilag, Horizon that includes: speaking and lecture fees and travel reimbursement. Roberta Fantozzi reports a relationship with Novartis, Roche, Merck Serono, Bristol-Myers Squibb that includes: board membership and consulting or advisory. Antonio Carotenuto reports a relationship with Almirall, ECTRIMS- MAGNIMS, Biogen, Roche, Sanofi-Genzyme, Merck, Ipsen, Novartis that includes: funding grants. Doriana Landi reports a relationship with Biogen, Merck Serono, Teva, Bristol Myers Squibb, Mylan, Novartis, Roche, Horizon, Alexion, Sanofi-Genzyme, Novartis, Bayer-Schering that includes: speaking and lecture fees and travel reimbursement. Giacomo Lus reports a relationship with Biogen Idec, Merck Serono, Novartis, Sanofi- Aventis Pharmaceuticals, Teva neuroscience that includes: funding grants. Eleonora Cocco reports a relationship with Biogen, Merck, Novartis, Roche, Genzyme that includes: consulting or advisory and funding grants. Matteo Lucchini reports a relationship with Biogen, Merck Serono, Novartis, Roche, Sanofi-Genzyme, Almirall, Horizon, Bayer that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement. Girolama Alessandra Marfia reports a relationship with Almirall, Bayer-Schering, Biogen, Sanofi Genzyme, Merck Serono, Novartis, Teva, Mylan, Bristol Mayers Squibb, Roche, Biogen that includes: consulting or advisory, funding grants, speaking and lecture fees, and travel reimbursement. Matteo Foschi reports a relationship with Merck, Biogen, Sanofi, Roche, Novartis that includes: consulting or advisory and travel reimbursement. Massimiliano Mirabella reports a relationship with Bayer Schering, Biogen, Sanofi-Genzyme, Merck, Novartis, Teva, Mylan, Almirall, CSL Behring, Roche, Ultragenix that includes: board membership, consulting or advisory, speaking and lecture fees, and travel reimbursement. Diego Centonze reports a relationship with Almirall, Bayer Schering, Biogen, GW Pharmaceuticals, Merck Serono, Novartis, Roche, Sanofi-Genzyme, Protagon, Sandoz, Bristol-Myers Squibb, Alexion, Mitsubishi, Teva, Celgene that includes: board membership, funding grants, and non-financial support. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: The long-term effect of high efficacy disease modifying therapy (DMT) on neurodegeneration in people with multiple sclerosis (pwMS) is largely unknown. The aim of this study was to evaluate the long-term effect of natalizumab (NTZ) or fingolimod (FTY) therapy on the evolution of brain atrophy compared to moderate efficacy DMT in a real-world clinical setting., Methods: A total of 438 pwMS with 2,439 MRI exams during treatment were analyzed: 252 pwMS treated with moderate efficacy DMT, 130 with NTZ and 56 with FTY. Evolution of brain atrophy was analyzed over an average follow-up of 6.6 years after treatment initiation. Brain segmentation was performed on clinical 3D-FLAIRs using SynthSeg and regional brain volume changes over time were compared between the treatment groups., Results: Total brain, white matter and deep gray matter atrophy rates did not differ between moderate efficacy DMTs, NTZ and FTY. Annualized ventricle growth rates were lower in pwMS treated with NTZ (1.1 %/year) compared with moderate efficacy DMT (2.4 %/year, p < 0.001) and similar to FTY (2.0 %/year, p = 0.051). Cortical atrophy rates were lower in NTZ (-0.08 %/year) compared with moderate efficacy DMT (-0.16 %/year, p = 0.048)., Conclusion: In a real-world clinical setting, pwMS treated with NTZ had slower ventricular expansion and cortical atrophy compared to those treated with moderate efficacy DMT., Competing Interests: Declaration of competing interest E.M.M. Strijbis, E.M.E. Coerver, Z.L.E. van Kempen and B. Jasperse have nothing to disclose. S. Noteboom is supported by research grants from Atara Biotherapeutics, Merck and Biogen. J. Killestein reports grants from Biogen, Novartis, TEVA, Bayer Schering Pharma, Glaxo Smith Kline, Merck, Genzyme and Roche. H. Vrenken has received research grants from Pfizer, Merck Serono, Novartis, and Teva, speaker honoraria from Novartis, and consulting fees from Merck Serono; all funds were paid directly to his institution. M.M. Schoonheim serves on the editorial board of Neurology and Frontiers in Neurology, receives research support from the Dutch MS Research Foundation, Eurostars-EUREKA, ARSEP, Amsterdam Neuroscience, MAGNIMS and ZonMW (Vidi grant, project number 09150172010056) and has served as a consultant for or received research support from Atara Biotherapeutics, Biogen, Celgene/Bristol Meyers Squibb, EIP, Sanofi, MedDay and Merck. M.D. Steenwijk is supported by research grants from Atara Biotherapeutics, Merck and Biogen., (Copyright © 2024. Published by Elsevier B.V.)

Importance: Vaccination in patients with highly active multiple sclerosis (MS) requiring prompt treatment initiation may result in impaired vaccine responses and/or treatment delay., Objective: To assess the immunogenicity and safety of inactivated vaccines administered during natalizumab treatment., Design, Setting, and Participants: This self-controlled, prospective cohort study followed adult patients with MS from 1 study center in Spain from September 2016 to February 2022. Eligible participants included adults with MS who completed immunization for hepatitis B virus (HBV), hepatitis A virus (HAV), and COVID-19 during natalizumab therapy. Data analysis was conducted from November 2022 to February 2023., Exposures: Patients were categorized according to their time receiving natalizumab treatment at the time of vaccine administration as short-term (≤1 year) or long-term (>1 year)., Main Outcomes and Measures: Demographic, clinical, and radiological characteristics were collected during the year before vaccination (prevaccination period) and the year after vaccination (postvaccination period). Seroprotection rates and postvaccination immunoglobulin G titers were determined for each vaccine within both periods. Additionally, differences in annualized relapse rate (ARR), new T2 lesions (NT2L), Expanded Disability Status Scale (EDSS) scores, and John Cunningham virus (JCV) serostatus between the 2 periods were assessed., Results: Sixty patients with MS (mean [SD] age, 43.2 [9.4] years; 44 female [73.3%]; 16 male [26.7%]; mean [SD] disease duration, 17.0 [8.7] years) completed HBV, HAV, and mRNA COVID-19 immunization during natalizumab treatment, with 12 patients in the short-term group and 48 patients in the long-term group. The global seroprotection rate was 93% (95% CI, 86%-98%), with individual vaccine rates of 92% for HAV (95% CI, 73%-99%), 93% for HBV (95% CI, 76%-99%), and 100% for the COVID-19 messenger RNA vaccine (95% CI, 84%-100%). Between the prevaccination and postvaccination periods there was a significant reduction in the mean (SD) ARR (0.28 [0.66] vs 0.01 [0.12]; P = .004) and median (IQR) NT2L (5.00 [2.00-10.00] vs 0.81 [0.00-0.50]; P = .01). No changes in disability accumulation were detected (median [IQR] EDSS score 3.5 [2.0-6.0] vs 3.5 [2.0-6.0]; P = .62). No differences in safety and immunogenicity were observed for all vaccines concerning the duration of natalizumab treatment., Conclusions and Relevance: The findings of this cohort study suggest that immunization with inactivated vaccines during natalizumab therapy was both safe and immunogenic, regardless of the treatment duration. Natalizumab may be a valuable option for proper immunization, averting treatment delays in patients with highly active MS; however, this strategy needs to be formally evaluated.

Despite its widespread use in clinical practice, the effectiveness of natalizumab extended interval dosing (EID) adopted from treatment start across different treatment intervals and individual modifiers (body mass index - BMI) is still under-investigated. Here, seven-hundred and forty-five multiple sclerosis (MS) patients, exposed to natalizumab for 3.30 ​± ​1.34 years, were retrospectively enrolled in an observational multicenter study. After stratifying patients in EID or standard interval dosing (SID), we assessed differences in time to relapse, MRI activity and Expanded Disability Status Scale (EDSS) progression. The primary analysis was conducted on patients exposed to EID interval from 5 weeks and 1 day to 7 weeks, while a secondary analysis included also EID periods up to 8 weeks. An additional analysis explored the impact of BMI. No differences in time to first relapse, time to radiological activity, time to EDSS progression or time to EDA (evidence of disease activity) were detected between SID and EID group (EID interval from 5 weeks to 1 day to 7 weeks). When including EID periods from 7 weeks and 1 day to 8 weeks, the EID group showed a trend towards higher risk of experience clinical relapses than the SID group. A higher EDA risk was also identified in EID patients with BMI above median. In conclusion, a higher risk of relapses seems to occur for EID above 7 weeks. Independently from the EID scheme adopted, higher BMI increases the risk of EDA in these patients., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Carlo Pozzilli reports financial support was provided by Biogen. Many authors (see manuscript) reports a relationship with Teva, Janssen, Merck, Biogen, Novartis, Eisai, Intercept, Bayer, Sanofi, Genzyme, Bristol, Almirall, GW, Roche, Mitsubishi, Celgene, Actelion, Serono Foundation, CSL, Behring, Ultragenix, Horizon, HEALTH&LIFE, AIM Education, FARECOMUNICAZIONE E20 that includes: board membership, consulting or advisory, funding grants, speaking and lecture fees, and travel reimbursement., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Multiple sclerosis (MS) is a chronic inflammatory, immune-mediated disease affecting the central nervous system. Natalizumab, an FDA-approved monoclonal antibody for MS, has been explored for its off-label extended interval dosing (EID), suggesting a potential reduction in the risk of progressive multifocal leukoencephalopathy (PML) compared to standard interval dosing (SID). Our objective was to assess the efficacy and safety of EID in comparison to SID for natalizumab treatment in patients with MS., Methods: We searched PubMed, Embase, WOS, Scopus, Ovid, Science Direct, Clinical trials.gov, and Cochrane Library. Our assessed outcomes were clinical relapses, MRI activity, change in expanded disability status scale [EDSS], and the risk of PML. The EID group was defined as 5 to 8 weeks [EID (Q5-8W)]. The analysis was conducted using RevMan ver. 5.4. The effect estimates were presented as a risk ratio [RR] or mean difference with 95% confidence intervals [CI] using SID group as the reference for comparisons., Results: Fourteen studies met our inclusion criteria: 2 RCTs, 1 switched single-arm trial, and 12 observational studies. No significant differences were found in all efficacy outcomes of interest. Risk of clinical relapses [RR = 0.90, (95%CI 0.80, 1.02)], risk of new or newly enlarging T2 hyperintense MRI lesions [RR = 0.78, (95%CI 0.59, 1.04)], risk gadolinium enhancing lesions [RR = 1.30, (95%CI 0.98, 1.72)], change in EDSS [MD = 0.09 (95%CI - 0.57, 0.76)], risk of PML [RR = 1.09, 95%CI (0.24, 4.94)]., Conclusion: In summary, our meta-analysis indicates that natalizumab maintains its effectiveness under extended interval dosing [up to 8 weeks], presenting comparable risks for clinical relapses, MRI lesions, EDSS, and PML. Caution is advised given study limitations and heterogeneity. Robust conclusions necessitate well-designed high-quality prospective studies., (© 2024. The Author(s).)

Background: The decision of initiating treatment for multiple sclerosis (MS) with a high-efficacy DMT (HE DMT) or non-high-efficacy DMT (non-HE DMT) is influenced by several factors, including risk perception of patients and physicians., Objective: Investigate the influence of physicians' risk perception on decision-making when switching treatments for MS and the reasons for switching., Methods: Data were drawn from the Adelphi Real-World MS Disease-Specific Program (a retrospective survey) and analysis included people with RMS identified between 2017- 2021., Results: Of 4129 patients with reasons for switch available, 3538 switched from non-HE DMT and 591 from HE DMT. Overall, 4.7% of patients were switched treatment by their physicians due to the risk of malignancies and infections including PML risk. The proportion of switches that were made due to the risk of PML were 23.9% in the HE DMT and 0.5% in the non-HE DMT groups. The top reasons for switching were relapse frequency (non-HE DMT vs HE-DMT: 26.8% vs 15.2%), lack of efficacy (20.9 vs 11.7) and increased number of MRI lesions (20.3% vs 12.4%)., Conclusions: Physicians' risk perception of malignancies and infection excluding PML was not a leading factor when switching treatment. The risk of PML was a key factor, especially for switching patients from HE DMTs. In both groups, lack of efficacy was the key contributing factor for switching. Initiating the treatment with HE DMTs may potentially reduce the number of switches due to sub-optimal efficacy. These findings might help physicians to engage more in discussions with patients about the benefit/risk profile of DMTs., Competing Interests: Declaration of Competing Interest Tarunya Arun has nothing to disclose. Carlos Capela has received consulting fees from Janssen, Merck and Roche, has received payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Almirall, Biogen, Bristol Myers Squibb, Janssen, Merck, Novartis, Roche, Sanofi-Genzyme and Teva, has received support for attending meetings and/or travel from Almirall, Bayer, Merck, Novartis, Roche, Sanofi-Genzyme and Teva, has participated on a Data Safety Monitoring Board or Advisory Board for Biogen, Janssen, Merck, Novartis, Roche and Sanofi-Genzyme. Guy Laureys and/or his employer (UZ Ghent) have received financial compensation for congress attendance, consultancy, research and education by Almirall, Biogen, Celgene, Bristol Myers Squibb, Novartis, Roche, Sanofi, Teva. Pietro Iaffaldano and/or his institution has received medical writing support for present manuscript from Novartis, has received grants from Novartis, Biogen and Roche; has received consulting fees from Novartis, Biogen, Sanofi, genzyme, BMS, Merck and Roche; has received payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Roche, Biogen, Sanofi and Merck; support for attending meetings and/or travel from Biogen, Sanofi and Merck and participated on a data safety monitoring board or advisory board for Novartis, Biogen, Sanofi, Genzyme, BMS, Merck and Roche. Eddie Jones is an employee of Adelphi Real World. Adelphi Real World received funds from Novartis in exchange for access to the MS DSP data set that was used for analysis. Eddie Jones did not receive any funding directly from Novartis. Patricia Dominguez-Castro, and Simone Hiltl are employees of Novartis Pharma AG. Gustavo Seifer was an employee of Novartis Pharma AG at the time of study design, execution, interpretation and submission. Rainel Sanchez-de la Rosa was an employee of Novartis Pharma AG at the time of study design and execution., (Copyright © 2023. Published by Elsevier B.V.)

Background: Natalizumab is a humanized monoclonal antibody with high efficacy and an acceptable safety profile used in the treatment of patients with multiple sclerosis (MS)., Objective: Our aim was to report data regarding long-term administration of Natalizumab in patients with Relapsing-Remitting Multiple Sclerosis (RRMS) from our clinic., Methods: A retrospective observational study was performed including RRMS patients who underwent treatment with ≥ 24 Natalizumab infusions. We analyzed EDSS values, the relapse rate and the rate and type of adverse events related to Natalizumab administration., Results: 51 subjects were included with a predominance of women (62.74%), with an average age of 40.43±1.49 years, a mean disease duration of 9.86±0.7 years and mean number of Natalizumab infusions of 45.58±2.74. An increased number of patients (80.39%) were relapse-free and a mild reduction of the mean EDSS value following Natalizumab initiation in patients who had not been treated with other disease modifying therapies anteriorly was observed. Among the encountered adverse events such as increased liver transaminases (13.72%), local infections (7.84%) and dysmenorrhea in one patient were registered in this study. The rate of severe adverse events was 3.92 and no cases of Progressive Multifocal Leukoencephalopathy (PML) were registered., Conclusion: Natalizumab proves to be effective, has an adequate safety profile and can be administered with good tolerability for a rather extended period of time, provided that the patients are closely monitored., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Secondary immunodeficiencies (SIDs) are acquired conditions that may occur as sequelae of immune therapy. In recent years a number of disease-modifying therapies (DMTs) has been approved for multiple sclerosis and related disorders such as neuromyelitis optica spectrum disorders, some of which are frequently also used in- or off-label to treat conditions such as chronic inflammatory demyelinating polyneuropathy (CIDP), myasthenia gravis, myositis, and encephalitis. In this review, we focus on currently available immune therapeutics in neurology to explore their specific modes of action that might contribute to SID, with particular emphasis on their potential to induce secondary antibody deficiency. Considering evidence from clinical trials as well as long-term observational studies related to the patients' immune status and risks of severe infections, we delineate long-term anti-CD20 therapy, with the greatest data availability for rituximab, as a major risk factor for the development of SID, particularly through secondary antibody deficiency. Alemtuzumab and cladribine have relevant effects on circulating B-cell counts; however, evidence for SID mediated by antibody deficiency appears limited and urgently warrants further systematic evaluation. To date, there has been no evidence suggesting that treatment with fingolimod, dimethyl fumarate, or natalizumab leads to antibody deficiency. Risk factors predisposing to development of SID include duration of therapy, increasing age, and pre-existing low immunoglobulin (Ig) levels. Prevention strategies of SID comprise awareness of risk factors, individualized treatment protocols, and vaccination concepts. Immune supplementation employing Ig replacement therapy might reduce morbidity and mortality associated with SIDs in neurological conditions. In light of the broad range of existing and emerging therapies, the potential for SID warrants urgent consideration among neurologists and other healthcare professionals., (© 2021. The Author(s).)

Objective: The delivery of healthcare at home has expanded to intravenous infusions of monoclonal antibodies. A recently developed model of care for home infusions of natalizumab for people with relapsing-remitting multiple sclerosis was evaluated. This pilot study of home infusions of natalizumab and usual care (attendance in a hospital out-patients' clinic) compared safety, feasibility, patient satisfaction, effectiveness and costs., Methods: In this randomised AB/BA crossover trial, 37 adults were randomised to usual care (n = 19) or home infusions (n = 18). After three infusions, patients crossed over to the alternate treatment for another three infusions. Patient safety outcomes and adherence, satisfaction, quality of life, disability and costs were compared., Results: No adverse events were recorded from 207 infusions from 35 patients across both home and clinic infusions. There was no difference in adherence (p = 0.71) and infection rates (p = 0.84) between home and clinic settings. Satisfaction with "convenience" of home infusions was significantly greater (p = 0.008) but there were no differences in quality of life measures. Excluding pharmacy, costs were A$74 lower per infusion at home, including A$16 of patients" out-of-pocket costs., Interpretation: There were no differences in safety and effectiveness between clinic and home infusions of natalizumab. The home infusions were shown to be feasible, more convenient and less expensive than usual care. Larger scale studies are required to verify these preliminary findings, particularly around safety and management of hypersensitivity adverse events in the home setting and for equivalence of clinical outcomes., (© 2021 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Objectives: The study aimed to assess the potential for serum neurofilament light chain (NFL) levels to predict the risk of progressive multifocal leukoencephalopathy (PML) in natalizumab (NTZ)-treated patients with multiple sclerosis (MS) and to discriminate PML from MS relapses., Methods: NFL levels were measured with single molecule array (Simoa) in 4 cohorts: (1) a prospective cohort of patients with MS who developed PML under NTZ therapy (pre-PML) and non-PML NTZ-treated patients (NTZ-ctr); (2) a cohort of patients whose blood was collected during PML; (3) an independent cohort of non-PML NTZ-treated patients with serum NFL determinations at 2 years (replication cohort); and (4) a cohort of patients whose blood was collected during exacerbations., Results: Serum NFL levels were significantly increased after 2 years of NTZ treatment in pre-PML patients compared with NTZ-ctr. The prognostic performance of serum NFL levels to predict PML development at 2 years was similar in the NTZ-ctr group and replication cohort. Serum NFL levels also distinguished PML from MS relapses and were 8-fold higher during PML compared with relapses., Conclusions: These results support the use of serum NFL levels in clinical practice to identify patients with relapsing-remitting MS at higher PML risk and to differentiate PML from clinical relapses in NTZ-treated patients., Classification of Evidence: This study provides Class I evidence that serum NFL levels can identify NTZ-treated patients with MS who will develop PML with a sensitivity of 67% and specificity of 80%., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

The main aim of the study is to evaluate the efficacy and safety profile of ocrelizumab (OCR), rituximab (RTX), and cladribine (CLA), employed as natalizumab (NTZ) exit strategies in relapsing-remitting multiple sclerosis (RRMS) patients at high-risk for progressive multifocal leukoencephalopathy (PML). This is a multicentre, retrospective, real-world study on consecutive RRMS patients from eleven tertiary Italian MS centres, who switched from NTZ to OCR, RTX, and CLA from January 1st, 2019, to December 31st, 2019. The primary study outcomes were the annualized relapse rate (ARR) and magnetic resonance imaging (MRI) outcome. Treatment effects were estimated by the inverse probability treatment weighting (IPTW), based on propensity-score (PS) approach. Additional endpoint included confirmed disability progression (CDP) as measured by Expanded Disability Status Scale and adverse events (AEs). Patients satisfying predefined inclusion and exclusion criteria were 120; 64 switched to OCR, 36 to RTX, and 20 to CLA. Patients from the 3 groups did not show differences for baseline characteristics, also after post hoc analysis. The IPTW PS-adjusted models revealed that patients on OCR had a lower risk for ARR than patients on CLA (ExpB OCR 0.485, CI 95% 0.264-0.893, p = 0.020). This result was confirmed also for 12-month MRI activity (ExpB OCR 0.248 CI 95% 0.065-0.948, p = 0.042). No differences were found in other pairwise comparisons (OCR vs RTX and RTX vs CLA) for the investigated outcomes. AEs were similar among the 3 groups. Anti-CD20 drugs were revealed to be effective and safe options as NTZ exit strategies. All investigated DMTs showed a good safety profile., (© 2021. The Author(s).)

The extended interval dosing (EID) of natalizumab has been suggested to be associated with a reduced risk of progressive multifocal leukoencephalopathy (PML) and short-term preservation of efficacy but its long-term effectiveness remain unknown. We aimed to determine the long-term effectiveness and safety of natalizumab in an EID setting in a cohort of patients with multiple sclerosis (MS) treated for more than 7 years. We conducted an observational retrospective cohort study, including 39 (34 female, 5 male) patients with clinically definite relapsing-MS, initially treated with standard interval dosing (SID) of natalizumab (mean time 54 months [SD29]) who were then switched to EID, every 8 weeks (mean time 76 months [SD13]). The main outcome measures included the following: i) annualized relapse rate (ARR), ii) radiological activity, iii) disability progression, and iv) NEDA-3 no evidence of disease activity index. EID preserved ARR, radiological activity, and prevented disability worsening during follow-up. The proportion of patients maintaining their NEDA-3 status after 24, 48, and 72 months of natalizumab administration in EID was 94%, 73%, and 70%, respectively. Stratified analysis according to history of drug therapy showed that the EID of natalizumab was slightly more effective in naïve patients than in those previously treated with other immunosuppressive drugs. No cases of PML or other severe adverse reactions were reported. In conclusion, long-term therapy with natalizumab in an EID setting following an SID regimen maintained its disease-modifying activity, and was safe and well tolerated for over 7 years. These encouraging observational results need to be confirmed in controlled clinical trials., Competing Interests: JR has received travel grants or speaking fees from Merck, Sanofi-Genzyme, Roche, Biogen, and Novartis. JS has received travel grants from Merck. MM has received travel grants or speaking fees from Merck, Sanofi-Genzyme, and Biogen. TC-T has received speaking/consulting fees and/or travel funding from Bayer, Biogen, Merck, Novartis, Roche, Sanofi-Genzyme, and Teva. MD-A has received travel grants or speaking fees from Merck, Novartis, and Sanofi-Genzyme. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Riancho, Setien, Sánchez de la Torre, Torres-Barquin, Misiego, Pérez, Castillo-Triviño, Menéndez-García and Delgado-Alvarado.)

Natalizumab is approved for multiple sclerosis treatment at a dose of 300 mg every 4 weeks. Extended-interval dosing of natalizumab has been proposed as a strategy to mitigate the risk of progressive multifocal leukoencephalopathy, but the efficacy of extended-interval dosing is not established. Previous models suggesting lower efficacy when initiating natalizumab treatment with extended-interval dosing rather than every-4-week dosing are inconsistent with reports from clinical observations and real-world studies conducted in patient populations switching to extended-interval dosing after a period of receiving natalizumab every 4 weeks. Here, the efficacy of natalizumab extended-interval dosing was modeled specifically in patients switching from every-4-week dosing to extended-interval dosing. Published population pharmacokinetic/pharmacodynamic models were used to simulate the distribution of alpha-4 integrin saturations for different body weight categories and dosing intervals (every 5, 6, 7, 8, 10, or 12 weeks). Generalized estimating equations relating alpha-4 integrin saturation to probability of multiple sclerosis lesion or relapse were derived from RESTORE trial data, which included patients (n = 175) who discontinued natalizumab after being treated every 4 weeks for ≥1 year and had no relapses in the year before discontinuation. The model-based simulations described indicate that every-5-week or every-6-week dosing is likely to maintain the efficacy of natalizumab, particularly at body weights <80 kg, in patients who switch after a period of stability on every-4-week dosing. The efficacy of natalizumab decreases as dosing intervals and body weight increase. Partial model validation was achieved in that observed outcomes in an independent clinical study were similar to those predicted by the models., (© 2020 Biogen Inc. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Based on publicly available data, we reevaluated current algorithms for stratifying the risk of progressive multifocal leukoencephalopathy (PML) in natalizumab-treated patients with multiple sclerosis, and found that there are a number of issues. First and foremost, our analysis highlights the necessity of separate PML incidence assessments for the U.S. versus Europe, and indicates that the risk in John Cunningham virus (JCV) antibody-negative patients may be higher than previously communicated. Additionally, we advocate introducing a low-risk JCV index threshold of 0.45 for individuals with prior exposure to an immunosuppressant, and setting the low-risk threshold at 0.6 instead of 0.9 for those without such pretherapies. On the other hand, the risk of PML on natalizumab, in general, appears to not only plateau but to actually decrease after about 5 years of continuous dosing., (© 2021 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Background: The COVID-19 pandemic challenges multiple sclerosis services to be innovative in delivering infusible therapies. To reduce time in clinical settings, and potential staff or space losses, we implemented rapid infusion protocols for selected patients., Objective: To analyse the rate of infusion related reactions and patient experience of rapid infusions of natalizumab and ocrelizumab. To document time reduction patients spent in clinical settings during the COVID-19 pandemic., Methods: Patients with prior exposure to at least three natalizumab or two 300mg ocrelizumab infusions were approved for rapid protocols. A retrospective audit and survey were completed., Results: We analysed 269 rapid natalizumab infusions and 100 rapid ocrelizumab infusions. Infusion related reactions during the natalizumab or ocrelizumab infusions occurred in two patients (1.52%) and eight patients (8%), respectively. All infusion related reactions were mild to moderate and did not require infusion discontinuation. No infusion reactions occurred during the post-infusion observation. Patient experience was positive., Conclusion: Frequency or severity of infusion related reactions in rapid infusions were no different compared to published data. In the setting of COVID-19, pandemic rapid infusion protocols could potentially save hospital resources and limit patient exposure to a high-risk clinical setting while still maintaining ongoing treatment of multiple sclerosis., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Introduction: Natalizumab (NTZ) is one of the most effective treatment options for multiple sclerosis (MS) treatment. Our study aimed to evaluate the effectiveness of NTZ when administered according to the extended dosing strategy compared with standard 4-weekly administration in a large Italian MS population., Materials and Methods: This retrospective multicentre study included patients with relapsing-remitting MS (RR-MS) who received NTZ administrations between the 1 June 2012 and the 15 May 2018 and were followed by the 'Italian MS Register'. All patients with MS were stratified into two groups based on NTZ administration schedule: standard interval dosing (SID) patients who received infusions on average from 28 to 32 days (median 30) and extended interval dosing (EID) including patients who have been infused with interval between 33 and 49 days (median 43). Clinical data were assessed at baseline (before starting NTZ), after 12 (T1) and 24 months (T2) of treatment., Results: Out of 5231 patients with RR-MS screened, 2092 (mean age 43.2±12.0, 60.6% women) were enrolled. A total of 1254 (59.9%) received NTZ according to SID, and 838 (40.1%) according to EID. At 12 and 24 months, no differences in terms of annualised relapse rate and disability status were found between the two groups. Progression index and confirmed disability worsening were similar between the two groups., Discussion: The use of NTZ with an extended interval schedule showed similar effectiveness compared with SID. Unchanged clinical efficacy of EID schedule may raise the question of a possible advantage in terms of tolerability and safety., Competing Interests: Competing interests: CGC has received grants for congress participation from Almirall, Biogen, Merck Serono, Novartis, Roche, Sanofi Genzyme and Teva. GS received speaker’s honoraria, consulting fees, honoraria in advisory boards, support for attendance of scientific meetings from Meck Serono, Biogen, Novartis, Teva and Sanofi Genzyme. PR has received grants for speaking activities from Biogen, Merck Serono, Novartis, TEVA and grants for congress participation from Almirall, Biogen, Merck Serono, Novartis, Roche, Sanofi Genzyme and TEVA. LMG received speaker’s honoraria, consulting fees, honoraria in advisory boards, support for attendance of scientific meetings from Meck Serono, Biogen, Novartis, Teva and Sanofi Genzyme. SB received speaker’s honoraria, consulting fees, honoraria in advisory boards, support for attendance of scientific meetings from Meck Serono, Biogen, Novartis, Teva and Sanofi Genzyme. AL received speaker’s honoraria, consulting fees, honoraria in advisory boards, support for attendance of scientific meetings from Meck Serono, Biogen, Novartis, Teva and Sanofi Genzyme. MTF received speaker’s honoraria, consulting fees, honoraria in advisory boards, support for attendance of scientific meetings from Meck Serono, Biogen, Novartis, Teva and Sanofi Genzyme. ElC received speaker’s honoraria, support for attendance of scientific meetings from Meck Serono, Biogen, Novartis, Teva and Sanofi Genzyme. FG received honoraria in advisory boards, support for attendance of scientific meetings from Meck Serono, Biogen, Novartis, Teva and Sanofi Genzyme. MT received speaker’s honoraria, consulting fees, honoraria in advisory boards, support for attendance of scientific meetings from Meck Serono, Biogen, Novartis, Teva and Sanofi Genzyme. FP has received honoraria for speaking activities by Almirall, Bayer Schering, Biogen Idec, Merck Serono, Novartis, Roche, Sanofi Genzyme and TEVA; he also served as advisory board member the following companies: Bayer Schering, Biogen Idec, Merck Serono, Novartis, Roche, Sanofi Genzyme and TEVA; he was also funded by Pfizer and FISM for epidemiological studies; he received grants for congress participation from Almirall, Bayer Shering, Biogen Idec, Merck Serono, Novartis, Roche, Sanofi Genzyme and TEVA., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To evaluate risks of disease reactivity during pregnancy and postpartum following rituximab (RTX) and natalizumab (NTZ) suspension in women with MS., Methods: An observational cohort study of all women with MS disease onset before childbirth between 2006 and 2017. Women were identified through the Swedish MS Registry, a nationwide clinical register, with substratification into 3 groups: women who suspended RTX and NTZ within 6 months before conception and women who were not treated with any disease-modifying treatment (DMT) within 1 year of conception. The primary outcome was the annualized relapse rate (ARR) during pregnancy and 1 year postpartum., Results: We identified 2,386 women with MS onset before a live birth; of these, 76 women suspended RTX and 53 suspended NTZ, and 457 were untreated within 1 year before conception. In all women, regardless of the treatment type, the ARR declined from 0.05-0.04 prepregnancy to 0.03-0.02 during pregnancy, returning to prepregnancy rates at 3-6 months (0.05) postpartum. In the suspended cohort, 76% (98/129) of women resumed a DMT after delivery. The relapse rate 1 year postpartum was significantly higher in the suspended NTZ women compared with the suspended RTX women (adjusted rate ratio [aRR] 7.65, 95% CI 2.47-23.6) and was lower in the suspended RTX women compared with the untreated women (aRR 0.21, 95% CI 0.08-0.61)., Conclusion: Disease reactivity during the postpartum period was lower among women with MS who suspended RTX before pregnancy, relative to those who suspended NTZ and untreated women. These findings suggest that RTX may exert long-acting effects on MS disease activity that encompass pregnancy and postpartum periods., Classification of Evidence: This study provides Class IV evidence that in patients with MS who were on treatment before pregnancy, RTX reduces clinical disease activity compared with NTZ in the postpartum period., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

In multiple sclerosis, treatment start or switch is prompted by evidence of disease activity. Whilst immunomodulatory therapies reduce disease activity, the time required to attain maximal effect is unclear. In this study we aimed to develop a method that allows identification of the time to manifest fully and clinically the effect of multiple sclerosis treatments ('therapeutic lag') on clinical disease activity represented by relapses and progression-of-disability events. Data from two multiple sclerosis registries, MSBase (multinational) and OFSEP (French), were used. Patients diagnosed with multiple sclerosis, minimum 1-year exposure to treatment, minimum 3-year pretreatment follow-up and yearly review were included in the analysis. For analysis of disability progression, all events in the subsequent 5-year period were included. Density curves, representing incidence of relapses and 6-month confirmed progression events, were separately constructed for each sufficiently represented therapy. Monte Carlo simulations were performed to identify the first local minimum of the first derivative after treatment start; this point represented the point of stabilization of treatment effect, after the maximum treatment effect was observed. The method was developed in a discovery cohort (MSBase), and externally validated in a separate, non-overlapping cohort (OFSEP). A merged MSBase-OFSEP cohort was used for all subsequent analyses. Annualized relapse rates were compared in the time before treatment start and after the stabilization of treatment effect following commencement of each therapy. We identified 11 180 eligible treatment epochs for analysis of relapses and 4088 treatment epochs for disability progression. External validation was performed in four therapies, with no significant difference in the bootstrapped mean differences in therapeutic lag duration between registries. The duration of therapeutic lag for relapses was calculated for 10 therapies and ranged between 12 and 30 weeks. The duration of therapeutic lag for disability progression was calculated for seven therapies and ranged between 30 and 70 weeks. Significant differences in the pre- versus post-treatment annualized relapse rate were present for all therapies apart from intramuscular interferon beta-1a. In conclusion we have developed, and externally validated, a method to objectively quantify the duration of therapeutic lag on relapses and disability progression in different therapies in patients more than 3 years from multiple sclerosis onset. Objectively defined periods of expected therapeutic lag allows insights into the evaluation of treatment response in randomized clinical trials and may guide clinical decision-making in patients who experience early on-treatment disease activity. This method will subsequently be applied in studies that evaluate the effect of patient and disease characteristics on therapeutic lag., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: Limited comparative effectiveness data for rituximab (RTX) versus natalizumab (NTZ), fingolimod (FTY), and dimethyl fumarate (DMF) for the treatment of multiple sclerosis (MS) exist., Methods: Clinician-reported data on patients prescribed RTX, NTZ, FTY, or DMF for the treatment of MS at the Rocky Mountain MS Center at the University of Colorado were retrospectively collected. Outcomes included a composite effectiveness measure consisting of clinical relapse, contrast-enhancing lesions, and/or new T2 lesions, individual effectiveness outcomes, and discontinuation. Logistic regression was used on patients matched by propensity scores and using average treatment effect on treated doubly robust weighting estimator., Results: A total of 182, 451, 271, and 342 patients initiated RTX, NTZ, FTY, and DMF and were followed for 2 years. Before and after adjustment, the odds of experiencing disease activity was significantly higher for FTY [adjusted OR (aOR) = 3.17 (95% CI: 1.81-5.55), P < 0.001].and DMF [aOR = 2.68 (95% CI:1.67-4.29), P < 0.001], and similar for NTZ [aOR = 1.36 (95% CI:0.83-2.23), P = 0.216] versus RTX. When examining months 6-24, NTZ demonstrated higher odds of disease activity compared to RTX [aOR = 2.21 (95% CI: 1.20-4.06), P = 0.007]. Similar odds of discontinuation were seen between NTZ and RTX [aOR = 1.39 (95% CI: 0.88-2.20), P = 0.157]; however, FTY [aOR = 2.02 (95% CI: 1.24-3.30), P = 0.005] and DMF [aOR = 3.27 (95% CI: 2.15-4.97), P < 0.001] had greater odds of discontinuation than RTX., Interpretation: RTX demonstrated superior effectiveness and discontinuation outcomes compared to FTY and DMF. Although RTX demonstrated similar effectiveness and discontinuation compared to NTZ, RTX had superior effectiveness during months 6-24 and fewer discontinuations when excluding discontinuations due to insurance issues. Results suggest superiority of RTX in reducing disease activity and maintaining long-term treatment in a real-world MS cohort., (© 2020 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Objective: We evaluated the effect of 2 doses of natalizumab on functional outcomes in patients with acute ischemic stroke (AIS)., Methods: In this double-blind phase 2b trial, patients with AIS aged 18-80 years with NIH Stroke Scale scores of 5-23 from 53 US and European sites were randomized 1:1:1 to receive a single dose of 300 or 600 mg IV natalizumab or placebo, with randomization stratified by treatment window (≤9 or >9 to ≤24 hours from patient's last known normal state). The primary endpoint was a composite measure of excellent outcome (modified Rankin Scale score ≤1 and Barthel Index score ≥95) at day 90 assessed in all patients receiving a full dose. Sample size was estimated from a Bayesian model; p values were not used for hypothesis testing., Results: An excellent outcome was less likely with natalizumab than with placebo (natalizumab 300 or 600 mg odds ratio 0.60; 95% confidence interval 0.39-0.93). There was no effect modification by time to treatment or use of thrombolysis/thrombectomy. For natalizumab 300 mg, 600 mg, or placebo, there were no differences in incidence of adverse events (90.0%, 92.1%, and 92.3%, respectively), serious adverse events (25.6%, 32.6%, and 20.9%, respectively), or deaths (6.7%, 4.5%, and 5.5%, respectively)., Conclusions: Natalizumab administered ≤24 hours after AIS did not improve patient outcomes., Clinicaltrialsgov Identifier: NCT02730455 CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for patients with AIS, an excellent outcome was less likely in patients treated with natalizumab than with placebo., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: To determine whether natalizumab efficacy is maintained when switching to personalized extended interval dosing based on individual natalizumab trough concentrations in patients with relapsing-remitting multiple sclerosis (RRMS)., Methods: This was a prospective multicenter single-arm trial with 1 year follow-up and a 1-year extension phase. Participants were adult persons with RRMS treated with natalizumab without disease activity in the year prior to enrollment. The natalizumab treatment interval was based on longitudinal natalizumab trough concentrations. Patients received 3 monthly MRI scans, relapse assessments, and disability scoring during follow-up. The primary endpoint was the occurrence of gadolinium-enhancing lesions on MRI. Secondary endpoints were new/enlarging T2 lesions on MRI and relapses and progression on the Expanded Disability Status Scale (EDSS) during follow-up and extension phase., Results: Sixty-one patients were included. Eighty-four percent extended the interval from a 4-week interval to a 5- to 7-week interval. No patient developed gadolinium-enhancing lesions (95% confidence interval [CI] 0%-7.4%) during follow-up. No new/enlarging T2 lesions (95% CI 0%-7.4%) or relapses (95% CI 0%-7.4%) were reported during follow-up and in the extension phase. Median EDSS was comparable at baseline (3.0, interquartile range [IQR] 2.0-5.0) and after follow-up (3.0, IQR 2.0-5.0)., Conclusion: Personalized extended interval dosing did not induce recurrence of MS disease activity. Natalizumab efficacy was maintained in stable patients with RRMS receiving personalized extended interval dosing based on individual natalizumab concentrations., Classification of Evidence: This study provides Class IV evidence that personalized extended interval dosing of natalizumab does not result in recurrence of disease activity in stable patients with RRMS., (© 2020 American Academy of Neurology.)

Background: Several disease modifying drugs (DMDs) have been approved for the treatment of multiple sclerosis (MS), however, little is known about their differential impact on peripheral blood (PB) B cell subsets., Methods: We performed a cross sectional study on PB B cells in MS patients treated with interferon-β (n = 25), glatiramer acetate (n = 19), dimethyl fumarate (n = 15), fingolimod (n = 16) or natalizumab (n = 22), untreated MS patients (n = 20), and in patients with non-inflammatory neurological diseases (n = 12). Besides analyzing routine laboratory data, flow cytometry was performed to analyze naïve B cells (CD19+CD20+CD27-IgD+), non-class switched (CD19+CD20+CD27+IgD+) and class-switched memory B cells (CD19+CD20+CD27+IgD-), double negative B cells (CD19+CD20lowCD27-IgD-) and plasmablasts (CD19+CD20lowCD27+CD38++)., Results: Treatment associated changes were found for the overall B cell pool as well as for all B cell subsets. Natalizumab increased absolute numbers and percentage of all B cells mainly by expanding the memory B cell pool. Fingolimod decreased absolute numbers of all B cell subsets and the percentage of total B cells. Fingolimod, dimethyl fumarate and interferon-β treatments were associated with an increase in the fraction of naïve B cells while class switched and non-class switched memory B cells showed decreased percentages., Conclusion: Our results highlight differential effects of DMDs on the PB B cell compartment. Across the examined treatments, a decreased percentage of memory B cells was found in dimethyl fumarate, interferon-β and fingolimod treated patients which might contribute to the drugs' mode of action in MS. Further studies are necessary to decipher the exact role of B cell subsets during MS pathogenesis., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: C.L. Kemmerer: reports no disclosures. V. Pernpeitner: reports no disclosures. C. Ruschil: reports no disclosures. A. Abdelhak: received research funding from the German multiple sclerosis society (DMSG) as well as travel grants from Teva and Novartis all not related to this work. M. Scholl: reports no disclosures. U. Ziemann: UZ has received honoraria from Biogen Idec GmbH, Bayer Vital GmbH, Bristol Myers Squibb GmbH, Pfizer, CorTec GmbH, Medtronic GmbH, and grants from European Research Council, German Research Foundation, German Ministry of Education and Research, Biogen Idec GmbH, Servier, and Janssen Pharmaceuticals NV, all not related to this work. M. Krumbholz: receives financial support from Sanofi-Genzyme, Merck, Novartis, Biogen, Celgene and Roche, not related to this study. B. Hemmer has served on scientific advisory boards for Novartis; he has served as DMSC member for AllergyCare and TG therapeutics; he or his institution have received speaker honoraria from Desitin; holds part of two patents; one for the detection of antibodies against KIR4.1 in a subpopulation of MS patients and one for genetic determinants of neutralizing antibodies to interferon. All conflicts are not relevant to the topic of the study. M.C. Kowarik: receives financial support from Merck, Sanofi-Genzyme, Novartis, Biogen, Celgene and Roche, not related to this study. The competing interests do not alter our adherence to PLOS ONE policies on sharing data and materials.

Progressive multifocal leukoencephalopathy (PML) is a viral disease of the brain associated with immunodeficiency, immune suppressing medications, and malignancy. In the absence of effective anti-viral therapy for the causative JC virus, immune restoration has emerged as the critical therapeutic alternative. The evolving treatment of PML (and other rare JC virus-associated neurologic syndromes) requires consideration of baseline immune functioning and comorbid diseases while selecting from a number of therapeutic options to restore an effective immune response. This review focuses on the current options for management of PML in typical situations where this disease presents, including several where immune restoration is a standard therapeutic approach such as in PML associated with HIV/AIDS and in multiple sclerosis associated with natalizumab. Other circumstances in which PML occurs including associated with primary immunodeficiencies, malignancies, and transplants present greater challenges to immune reconstitution, but emerging concepts may enhance therapeutic options for these situations. Particular attention is focused on recent experience with checkpoint inhibitors, guidance for MS drug discontinuation, and strategies to monitor and facilitate immune restoration.

Background: The risk of progressive multifocal leukoencephalopathy (PML), a brain infection caused by John Cunningham virus (JCPyV), is the main limitation to the use of natalizumab, highly effective in the treatment of relapsing remitting multiple sclerosis (RRMS) patients. Establishing the PML risk against expected benefits represents an obligatory requirement of MS treatment algorithm. In order to achieve this goal, the aims of this study were to establish if JCPyV-DNA detection and non-coding control region (NCCR) arrangements could play a role of biomarkers, supporting anti-JCPyV antibodies measurement, actually the only parameter for PML risk stratification., Methods: Thirty RRMS patients in treatment with natalizumab were enrolled. Urine and blood samples were collected according to this calendar: baseline (T0), 4 (T1), 8 (T2), 12 (T3), 16 (T4), 20 months (T5) after beginning of natalizumab therapy. After JCPyV DNA extraction, a specific quantitative-PCR (Q-PCR) and arrangements' analysis of NCCR and Viral Capsid Protein 1 (VP1) were carried out., Results: Q-PCR detected JCPyV DNA in urine and blood from baseline (T0) to 20 natalizumab infusions (T5), although JC viral load in urine was significantly higher compared to viremia, at all selected time points. A contextual analysis of the anti-JCPyV-antibodies versus JCPyV-DNA detection revealed that viral DNA preceded the antibodies' presence in the serum. During the first year of natalizumab treatment, sequences isolated from blood displayed an archetype JCPyV NCCR structure with the occurrence of point mutations, whereas after one year NCCR re-organizations were observed in plasma and PBMC with duplication of NF-1 binding site in box F, duplication of box C and partial or total deletion of box D. VP1 analysis showed the amino acid change mutation S269F in plasma and S267L in PBMC, involving the receptor-binding region of VP1. Phylogenetic analysis suggested a stability and a similarity across different isolates of the JCPyV VP1., Conclusions: We highly recommend considering JCPyV-DNA detection and NCCR re-organizations as viral biomarkers in order to accurately identify JCPyV-infected patients with a specific humoral response not yet detectable and to identify NCCR arrangements correlated with the onset of neurovirulent variants., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

The poor clinical relevance of experimental models of stroke contributes to the translational failure between preclinical and clinical studies testing anti-inflammatory molecules for ischemic stroke. Here, we (i) describe the time course of inflammatory responses triggered by a thromboembolic model of ischemic stroke and (ii) we examine the efficacy of two clinically tested anti-inflammatory drugs: Minocycline or anti-CD49d antibodies (tested in stroke patients as Natalizumab) administered early (1 h) or late (48 h) after stroke onset. Radiological (lesion volume) and neurological (grip test) outcomes were evaluated at 24 h and 5 days after stroke. Immune cell responses peaked 48 h after stroke onset. Myeloid cells (microglia/macrophages, dendritic cells, and neutrophils) were already increased 24 h after stroke onset, peaked at 48 h, and remained increased-although to a lesser extent-5 days after stroke onset. CD8 + and CD4 + T-lymphocytes infiltrated the ipsilateral hemisphere later on (only from 48 h). These responses occurred together with a progressive blood-brain barrier leakage at the lesion site, starting 24 h after stroke onset. Lesion volume was maximal 24-48 h after stroke onset. Minocycline reduced both lesion volume and neurological deficit only when administered early after stroke onset. The blockade of leukocyte infiltration by anti-CD49d had no impact on lesion volume or long-term neurological deficit, independently of the timing of treatment. Our data are in accordance with the results of previous clinical reports on the use of Minocycline and Natalizumab on ischemic stroke. We thus propose the use of this clinically relevant model of thromboembolic stroke with recanalization for future testing of anti-inflammatory strategies for stroke.

Background: Many natalizumab treated patients experience end of dose interval (EDI) symptoms towards the end of the administration cycle. Natalizumab has previously shown to influence cytokine profiles in relapsing remitting MS patients. We hypothesize that EDI symptoms might be explained by variability in serum cytokine levels during natalizumab treatment., Methods: 42 relapsing remitting MS patients were included. Participants were evaluated before natalizumab administration (day 0) and 7 days afterwards (day 7). At both time points fatigue, depressed mood and cognition were evaluated using the fatigue severity scale (FSS), the visual analogue scale for fatigue (VAS-F), the symbol digit modality test (SDMT) and the inventory for depressive symptomatology (IDS-SR). Serum samples were tested for concentrations of IL-6, IFN-γ and TNF-α at both timepoints. On day 7 an additional EDI questionnaire was completed. Data were analyzed with SPSS by means of non-parametric tests., Results: EDI symptoms were reported by 59.5%. Although fatigue was most frequently reported, fatigue scales did not significantly change from day 0 to 7 in (fatigued) EDI patients. Mood and cognition significantly ameliorated in both EDI and non-EDI patients. Cytokines remained stable at day 0 vs 7 except for a significant increase in IFN-γ. On day 0, IFN-γ concentration was positively correlated with a depressed mood in the whole cohort, and with mood and fatigue in the EDI group. Depressed mood positively whilst cognition negatively correlated with IFN-γ concentration on day 0 in the EDI subgroup reporting fatigue. No significant correlations between IL-6 nor TNF-α and symptom scores could be found., Conclusion: In our study EDI symptoms could not be objectified since EDI and non-EDI groups did not differ in terms of change in mood, cognition and fatigue between day 0 and 7 suggesting that symptom recrudescence could be a subjective experience. Although our results need to be interpreted cautiously, we found no clear correlation between studied serum cytokines concentrations and the occurrence of EDI symptoms., Competing Interests: Declaration of Competing Interest This study was sponsored by Biogen as an investigator-initiated trial. The authors maintained full editorial control of all content. Dekeyser Cathérine: has received travel compensation from Biogen; De Pue Annelien: has received travel compensation from Biogen; Sieben Anne: nothing to disclose; Algoed Luc: has received travel compensation from Biogen; Vanhijfte Liesbeth: nothing to disclose; Sarah Gerlo: nothing to disclose; Laureys Guy: has received travel compensations, consultancy and speakers fees from Biogen, (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: Natalizumab (NTZ) can be associated with an opportunistic infection, progressive multifocal leukoencephalopathy (PML), caused by John Cunningham virus (JCV). High titer of anti-JCV antibody (JCV index) in patients treated with NTZ for over 2 years limit it use, leading to treatment discontinuation., Objective: Aim of the study was to investigate the JCV index changes pre, during and post NTZ treatment and describe the trend after a long period of NTZ discontinuation., Methods: Patients with relapsing-remitting multiple sclerosis (RR-MS) treated with NTZ between 2010 and 2018 were enrolled in this retrospective-prospective observational study. Inclusion criteria were: (1) diagnosis of RR-MS according to the McDonald criteria 2010, (2) at least six NTZ administrations, (3) at least two determinations of JCV Index during the follow-up period, (4) NTZ discontinuation period for more than 6 months. JCV index was determined by STRATIFY II. There were three different timepoints: NTZ initiation (T0), NTZ discontinuation (T1) and time after NTZ suspension (T2). Seroconversion was defined as changing status of serum JCV antibody. Main outcomes were the JCV index changes and the rate of seroconversion., Results: At baseline we enrolled 285 patients (208 JCV negative, 67 JCV positive, and 10 not available). There was a statistically significant increase of JCV index during NTZ treatment period (T0 vs T1, p =0.0009) and during NTZ discontinuation period (T1 vs T2, p =0.04). Patients seroconverted to a positive status more frequently during NTZ treatment than after discontinuation (p =0.008). Moreover, patients who shifted to fingolimod (FTY) as exit strategy after NTZ discontinuation, showed a statistically significant increase of JCV index., Conclusion: Our data confirmed that a high percentage of patients shift to or remain in a positive JCV status during NTZ treatment and after discontinuation. NTZ suspension seems not to be able to interfere on JCV status modification over an extended period. The choice of alternative treatment as exit strategy after NTZ discontinuation should be carefully considered because it could negatively influence the PML risk stratification of patients.

Background: Natalizumab, a monoclonal antibody directed against alpha-4-integrin, is an efficacious treatment used in Multiple Sclerosis (MS). Use in early pregnancy is safe but information in the third trimester is limited. Ceasing natalizumab is often associated with an increased risk in MS relapse and in some instances natalizumab continuation during pregnancy may be required. However natalizumab crosses the placenta in late pregnancy and has been associated with hematological abnormalities. We present clinical and hematological outcome data of newborns from a series of MS patients who received natalizumab during their second and third pregnancy trimesters. We describe possible methods to mitigate risks to the fetus., Methods: Retrospective chart review of 15 births from mothers receiving natalizumab throughout pregnancy., Results: Thirteen mothers with third-trimester exposure to natalizumab were identified. Median age at conception was 34 years (26-40) and median disease duration was 53.5 months (11-204). The 13 mothers gave birth to 15 newborns (2 mothers each with 2 individual births), median (SD) birth weight was 2778 gs (2100 - 3790). Congenital or laboratory abnormalities were identified in 5 which included anemia (n = 2) and thrombocytopenia (n = 3)., Conclusions: Complications following natalizumab administration during the second and third trimester of pregnancy occurred in 33% of newborns. However, did not result in mortality or morbidity. Dose alterations during the third trimester, pre-delivery umbilical cord sampling and IVIG administration may reduce hematological effects on newborns. Prospective studies with larger numbers of patients are required to provide further evidence regarding the safety of Natalizumab use in pregnancy., Competing Interests: Declaration of Competing Interest James Triplett, Srimathy Vijayan, SIvaajani Rajanayagam and Phillip Tuch have no disclosures. Allan Kermode has received speaker honoraria and Scientific Advisory Board fees from Bayer, BioCSL, Biogen-Idec, Lgpharma, Merck, Novartis, Roche, Sanofi-Aventis, Sanofi-Genzyme, Teva, NeuroScientific Biopharmaceuticals and Innate Immunotherapeutics. He is currently an investigator in pharmaceutical trials sponsored by Biogen-Idec, Novartis, and Innate Immunotherapeutics., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: In the Brazilian public healthcare system, natalizumab is recommended as fourth-line treatment for relapsing-remitting multiple sclerosis (RRMS). Although natalizumab has already demonstrated higher effectiveness compared with fingolimod in some studies, this real-world study was conducted to evaluate annualized hospitalization rates (AHR) in Brazil for both treatments when switching from platform therapies. As secondary goals, we analyzed RRMS treatment patterns and hospitalization profiles., Material and Methods: We extracted data from the DATASUS database of patients with MS (ICD-10 G35) who initiated treatment from January 2012 to December 2017. Two cohorts were screened for different purposes. Cohort 1 was used to analyze treatment patterns and hospitalization profiles and was defined as individuals who had at least one claim related to MS therapies and had received at least two lines of treatment. The second cohort, which was a subset of the first, was used to compare natalizumab's and fingolimod's AHR reduction from previous treatment lines and included patients switching from platform therapy to one of these two drugs. Cohort 2 adjustment was assessed through two different statistical methods: propensity score (PS) and inverse probability weighting (IPW)., Results: Of 29,410 patients screened, 2,876 were included in cohort 1. Three quarters of hospitalizations reported in this cohort were for treatment of MS relapse. Cohort 2 included 1,005 patients, and natalizumab was more commonly used (n = 540) than fingolimod (n = 465). Both PS and IPW analyses showed that patients treated with natalizumab had a statistical significantly reduction in AHR compared with first-line treatment (p<0.01 for both PS and IPW), while fingolimod did not result in significant reduction in AHR (p = 0.20 for PS and p = 0.17 for IPW)., Conclusion: This study provides real-world evidence of natalizumab's and fingolimod's effectiveness in terms of AHR, with an increased reduction in AHR with natalizumab. The findings of this study also provide information to support disease management and healthcare planning in the Brazilian public healthcare system., Competing Interests: Ricardo Papaléo Rosim and Jéssica Rigolon are employees of Biogen Brazil; Guilherme Silva Julian is an employee of IQVIA Brazil who was contracted by Biogen to conduct the study. Estela Cristina Carneseca is an employee of Proestat Consultoria who was also contracted to conduct the analysis. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Objective: We aimed to investigate whether wearing-off symptoms at the end of the natalizumab dosing interval were associated with clinical and demographic patient characteristics or natalizumab receptor occupancy (RO) on leukocytes., Methods: In this cross-sectional study of 40 patients with relapsing-remitting MS (RRMS) receiving natalizumab at the Department of Neurology, Haukeland University Hospital, we recorded clinical and demographic data including age, body mass index (BMI), working status, smoking habits, disease characteristics, treatment duration, vitamin D levels, and wearing-off symptoms. We quantified neurofilament light chain in serum and measured natalizumab RO in leukocyte subtypes by high-parameter mass cytometry. Associations with wearing-off symptoms were analyzed., Results: Eight (20.0%) patients who reported regular occurrence of wearing-off symptoms, 9 (22.5%) who sometimes had wearing-off symptoms, and 23 (57.5%) who did not have wearing-off symptoms were evaluated. Patients who regularly had wearing-off symptoms had lower natalizumab RO than patients who reported having such symptoms sometimes or never. The former group also had higher BMI and higher frequency of sick leave. High BMI was associated with low RO. No other demographic or disease characteristics were associated with the phenomenon., Conclusions: Low RO may explain the wearing-off phenomenon observed in some patients with RRMS treated with natalizumab, and high BMI may be the underlying cause., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: To determine if the concentration and saturation of natalizumab (NTZ) administration at extended interval dosing (EID; every 5-8 weeks) over 18 months is able to be maintained in the range considered adequate to sustain the clinical efficacy of NTZ., Methods: In a cross-sectional assessment of patients with multiple sclerosis (MS) who received standard interval dosing (every 4 weeks) or EID, serum NTZ concentrations were measured using ELISA, and α 4 -integrin receptor saturations were analyzed via cytometry, in blood samples obtained at trough timepoints., Results: Trough serum concentration was above the "therapeutic" concentration of 2.0 μg/mL in 72% of EID patients. Trough saturation was above the "therapeutic" 50% threshold in 79% of EID-treated patients. Our model predicted that at least 9 NTZ infusions/year are required to maintain adequate trough saturation and concentration levels. Higher body mass index (BMI) was a predictor of suboptimal trough saturation on EID NTZ., Conclusions: Trough α4-integrin receptor saturation >50% correlated with high clinical efficacy of NTZ in previous studies. A continual treatment with EID maintains receptor saturation and concentration that are in the "therapeutic range" for most patients. This finding provides biological plausibility for the clinical efficacy of NTZ EID. Patients with higher BMI may require closer clinical and MRI follow-up., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background: Natalizumab (NTZ) is a humanized monoclonal antibody used in the treatment of relapsing remitting multiple sclerosis. Although NTZ is usually well-tolerated, infusion-related reactions (IRRs) may occur, and the patients have to be monitored during the infusion and for one hour afterwards., Objective: To identify frequency and severity of IRRs during NTZ infusions and one-hour post-infusion observation period in a clinical practice setting., Methods: Multicenter, observational study involving three Swiss (Lugano, St. Gallen and Luzern) and two Italian (Milano and Napoli) tertiary MS centers. Predisposing factors to IRRs were investigated using multivariate Cox regression models., Results: A total of 11'133 infusions received by 302 MS patients were analyzed (68.9% females, median age 33.6 years, median EDSS 2.5). IRRs occurred in 24 (8%) patients during NTZ infusions and in 7 (2%) during one-hour post-infusion. Only 8 patients needed pharmacological treatment, of whom 7 during NTZ infusion. Age, sex and history of allergies were not associated with risks for IRR. The frequency of post infusion IRRs after the fifth cycle was low compared to that during the first four infusions (0.83% vs 0.06%)., Conclusion: In our cohort, NTZ associated IRR mainly occurred during the infusion period compared to the one-hour observational period. Also, the first IRR exclusively occurred within the first 4 NTZ administrations. However, further multi-center studies with a larger sample size are needed to capture rare and serious events that could emerge during the observational period and to make clinical recommendations., Competing Interests: Declaration of Competing Interest Zecca C, Gobbi C received financial support for scientific activity, congress participation and speaking bureau from Almirall, Biogen, Bayer, CelleGene, Genzyme, Merck-Serono, Novartis, Roche, Teva Pharma. Sacco R, Disanto G, Maraffi I, Candrian U and Schwegler G declare that they have no conflict of interest Kamm CP has received honoraria for lectures as well as research support from Biogen, Novartis, Almirall, Bayer Schweiz AG, Teva, Merck, Sanofi Genzyme, Roche, Celgene and the Swiss MS Society (SMSG). Rossi S acted as an Advisory Board member of Biogen, Bayer Schering, Merck, Teva, Novartis, Genzyme, Mylan and received travel funding from Biogen, Merck, Teva, Novartis, Bayer Schering, Genzyme, Almirall, and received honoraria for consultancy, speaking or writing from Biogen, Merck, Teva, Novartis, Bayer Schering, Genzyme, Roche. She received support for research projects by Teva, Merck and Bayer Schering and is involved as principal investigator in clinical trials for Teva, Novartis, Biogen and Roche. Gallo A received honoraria for speaking and travel grants from Biogen, Sanofi-Aventis, Merck, Genzyme, Teva, and Novartis., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Natalizumab (NTZ) is widely used for highly active relapsing-remitting multiple sclerosis (MS). Inflammatory disease activity often returns after NTZ treatment discontinuation. We aimed to identify predictive factors for such reactivation in a real-life setting., Methods: We conducted a retrospective survey in four Finnish hospitals. A computer-based search was used to identify all patients who had received NTZ for multiple sclerosis. Patients were included if they had received at least six NTZ infusions, had discontinued treatment for at least three months, and follow-up data was available for at least 12 months after discontinuation. Altogether 89 patients were analyzed with Cox regression model to identify risk factors for reactivation, defined as having a corticosteroid-treated relapse., Results: At 6 and 12 months after discontinuation of NTZ, a relapse was documented in 27.0% and 35.6% of patients, whereas corticosteroid-treated relapses were documented in 20.2% and 30.3% of patients, respectively. A higher number of relapses during the year prior to the introduction of NTZ was associated with a significantly higher risk for reactivation at 6 months (Hazard Ratio [HR] 1.65, p < 0.001) and at 12 months (HR 1.53, p < 0.001). Expanded Disability Status Scale (EDSS) of 5.5 or higher before NTZ initiation was associated with a higher reactivation risk at 6 months (HR 3.70, p = 0.020). Subsequent disease-modifying drugs (DMDs) failed to prevent reactivation of MS in this cohort. However, when subsequent DMDs were used, a washout time longer than 3 months was associated with a higher reactivation risk at 6 months regardless of whether patients were switched to first-line (HR 7.69, p = 0.019) or second-line therapies (HR 3.94, p = 0.035). Gender, age, time since diagnosis, and the number of NTZ infusions were not associated with an increased risk for reactivation., Conclusion: High disease activity and a high level of disability prior to NTZ treatment seem to predict disease reactivation after treatment cessation. When switching to subsequent DMDs, the washout time should not exceed 3 months. However, subsequent DMDs failed to prevent the reactivation of MS in this cohort., Competing Interests: Declaration of Competing Interest The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article. IR has received research grants (The Finnish Medical Foundation, Orion Research Foundation sr) and reimbursement of travel expenses (Novartis). PH has received research grants (Biogen, Sanofi Genzyme), reimbursement of travel expenses and/or honoraria for lectures/consultations (Allergan, Biogen, Merck, NordicInfu Care, Roche, Sanofi Genzyme, SNY, Teva). JK has served on the scientific advisory board for Merck and Roche. SS has been the congress representative of Mikkeli Central Hospital sponsored by industry and has received honoraria for lectures/consultations (Biogen, Merck, Novartis, Sanofi Genzyme, Teva). AMR has received reimbursement of travel expenses and/or honoraria for lectures/consultations (Merck, Sanofi Genzyme, Novartis, Teva). HK has received honoraria for lectures/consultations (Biogen, Merck, Novartis, Roche, Sanofi Genzyme, Teva). TM, MN and TS have no conflict to declare., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective. Quantitatively summarize patient preferences for European licensed relapsing-remitting multiple sclerosis (RRMS) disease-modifying treatment (DMT) options. Methods. To identify and summarize the most important RRMS DMT characteristics, a literature review, exploratory physician interviews, patient focus groups, and confirmatory physician interviews were conducted in Germany, the United Kingdom, and the Netherlands. A discrete choice experiment (DCE) was developed and executed to measure patient preferences for the most important DMT characteristics. The resulting DCE data ( n =799 and n =363 respondents in the United Kingdom and Germany, respectively) were analyzed using Bayesian mixed logit models. The estimated individual-level patient preferences were subsequently summarized using 3 additional analyses: the quality of the choice data was assessed using individual-level R 2 estimates, individual-level preferences for the available DMTs were aggregated into DMT-specific preference shares, and a principal component analysis was performed to explain the patients' choice process. Results. DMT usage differed between RRMS patients in Germany and the United Kingdom but aggregate patient preferences were similar. Across countries, 42% of all patients preferred oral medications, 38% infusions, 16% injections, and 4% no DMT. The most often preferred DMT was natalizumab (26%) and oral DMT cladribine tablets (22%). The least often preferred were mitoxantrone and the beta-interferon injections (1%-3%). Patient preferences were strongly correlated with patients' MS disease duration and DMT experience, and differences in patient preferences could be summarized using 8 principle components that together explain 99% of the variation in patients' DMT preferences. Conclusion. This study summarizes patient preferences for the included DMTs, facilitates shared decision making along the dimensions that are relevant to RRMS patients, and introduces methods in the medical DCE literature that are ideally suited to summarize the impact of DMT introductions in preexisting treatment landscapes.

Background: Multiple sclerosis (MS) predominantly affects women of child-bearing potential. Pregnancy in MS is still a controversial issue lacking standardized treatment recommendations., Objective: To examine the reciprocal effects of pregnancy, MS, and disease-modifying treatment (DMT)., Methods: We analyzed 387 pregnancies in 239 women with relapsing remitting multiple sclerosis (RRMS) and ⩾1 pregnancy, establishment of diagnosis >1 year before conception, and ⩾2 years of follow-up after delivery. Relapse rates and Expanded Disability Status Scale (EDSS) scores were compared in the year before conception, during pregnancy, and 2 years postpartum. Binary logistic regression was used to investigate predictors of risk for relapses and disability progression during pregnancy and postpartum., Results: Risk of relapse and disability progression during pregnancy was predicted by pre-conception relapse activity, higher EDSS score at conception, use of highly effective disease-modifying treatment (H-DMT) pre-conception, and prolonged washout period. Postpartum relapse and disability progression was associated with relapse activity pre-conception and during pregnancy and use of H-DMT pre-conception. Early restart of DMT reduced the risk of postpartum relapse., Conclusion: A personalized approach in planning pregnancy in women with MS while on H-DMT needs to be adopted. It seems reasonable maintaining natalizumab closer to conception and restarting the drug early postpartum to reduce the considerable risk of disease reactivation during early pregnancy and after delivery.

Studies comparing the effects of natalizumab and fingolimod in relapsing-remitting multiple sclerosis (RRMS) are limited. We aimed to compare natalizumab and fingolimod effects on clinical, neuropsychological, and MRI measures in RRMS patients after 2 years of treatment. RRMS patients starting natalizumab (n = 30) or fingolimod (n = 25) underwent neurologic, neuropsychological, and brain MRI assessments at baseline, month (M) 6, M12, and M24. Volumes of lesions, brain, gray matter (GM), white matter (WM), and deep GM were measured. Fifteen healthy controls (HC) were also scanned at baseline and M24. Treatment groups were matched for baseline variables. At M24 versus baseline, both drugs reduced the relapse rate (p value < 0.001), stabilized disability, and improved cognitive function (fingolimod: p value = 0.03; natalizumab: p value = 0.01), without between-group differences. The natalizumab group had a higher proportion of freedom from MRI activity (67% vs 36%, p value = 0.02) and no evidence of disease activity-3 (NEDA-3) (57% vs 28%, p value = 0.04). At M24 vs M6, brain (- 0.35%, p value = 0.002 [fingolimod]; - 0.42%, p value < 0.001 [natalizumab]), GM (- 0.62%, p value < 0.001 [fingolimod]; - 0.64%, p value < 0.001 [natalizumab]), and WM (- 0.98%, p value < 0.001 [fingolimod]; - 0.99%, p value < 0.001 [natalizumab]) atrophy progressed at higher rates than in HC, but similarly between treatment groups, whereas only the natalizumab group showed deep GM atrophy (- 0.79%, p value = 0.02) (p value vs fingolimod not significant). In both groups, atrophy progression was correlated with lesion accumulation (r from - 0.49 to - 0.36, p values from 0.013 to 0.05), whereas no correlation was found between clinical and MRI changes. Natalizumab and fingolimod reduce disease activity and improve cognition in RRMS. Natalizumab seems superior to limit lesion accumulation, whereas both drugs similarly modify atrophy progression.

Extending the natalizumab interval after the 24th administration could reduce the risk of progressive multifocal leukoencephalopathy (PML). The objective is to evaluate the noninferiority of the efficacy of an extended interval dosing (EID) compared with the standard interval dosing (SID) of natalizumab. It is an observational, multicenter (14 Italian centers), retrospective cohort study, starting from the 24th natalizumab infusion to the loss of follow-up or 2 years after baseline. Patients were grouped in 2 categories according to the mean number of weeks between doses: < 5 weeks, SID; ≥ 5 weeks, EID. Three hundred and sixty patients were enrolled. Median dose interval (MDI) following 24th infusion was 4.7 weeks, with a bimodal distribution (modes at 4 and 6 weeks). Two hundred and sixteen patients were in the SID group (MDI = 4.3 weeks) and 144 in the EID group (MDI 6.2 weeks). Annualized relapse rate was 0.060 (95% CI = 0.033-0.087) in the SID group and 0.039 (95% CI = 0.017-0.063) in the EID group. The non-inferiority of EID versus SID was satisfied. In conclusion, there is no evidence of a reduced efficacy of natalizumab in an EID setting. This observation confirms previous results and together with the emerging evidence of a reduced risk of PML associated to an EID, supports the need of a randomized study to assess the need to change the standard of the natalizumab dosing schedule.

The objectives were to study the expression of very late antigen (VLA)-4, melanoma cell adhesion molecule-1 (MCAM-1) and activated leukocyte cell adhesion molecule (ALCAM) on CD4+ T cells during natalizumab treatment and to investigate the association with disease activity. We find that subgroups of autoreactive T cells are retained in peripheral blood, in particular MOG-reactive CD4+ T cells expressing MCAM-1. The expression of MCAM-1 or ALCAM on CD4+ T cells was, however, not clearly associated with disease activity (clinical or MRI) during natalizumab treatment. We confirm upregulation of MCAM-1 on CD4+ T cells during natalizumab treatment while VLA-4 is downregulated., (Copyright © 2019 Elsevier B.V. All rights reserved.)