Patients with relapsing-remitting multiple sclerosis (RRMS) may experience disability progression independent of relapse activity (PIRA), which can be an early sign of secondary progressive MS (SPMS). We defined persistent PIRA as ongoing sustained disability over the entire available follow-up period. However, PIRA events can regress over time. Identifying factors that predict PIRA persistence is of great interest as they can refine the definition of RRMS to SPMS transition. Equally, factors associated with the non-persistence of PIRA have potential treatment implications for patients suffering from a PIRA event. We conducted a study to examine risk factors for PIRA persistence and risk differences in long-term disability progression between persistent and non-persistent PIRA. In this cohort study, we included only patients who had already experienced a PIRA event and investigated the persistence of disability progression following their first PIRA event. Therefore, PIRA occurrence time was set as the baseline. Data were collected from the MSBase registry between April 1995 and January 2024, with a median follow-up of 8.7 years. The primary outcome was time to 6-month confirmed non-persistence of PIRA. Secondary outcomes comprised time to 6-month confirmed Expanded Disability Status Scale (EDSS) 6 and time to SPMS. A stratified Cox regression model was used to identify risk factors associated with non-persistent PIRA. We then matched persistent PIRA patients with non-persistent PIRA patients in a 1:1 ratio using propensity scores, and compared their risk of reaching EDSS 6 using the Cox regression model. We re-matched patients with complete Kurtzke Functional Systems Scores to compare their risks of reaching SPMS. We included 4713 RRMS patients with PIRA, of whom around one-third experienced a post-PIRA disability improvement, over a relatively long period (median of 2.6 years to improvement). Use of high-efficacy disease-modifying therapies (DMT) at baseline [hazard ratio, 1.22; 95% confidence interval, (1.08-1.38); P = 0.0015], lower baseline EDSS [hazard ratio, 0.73 (0.69-0.78); P < 0.0001] and younger age [per 10 years; hazard ratio, 0.84 (0.80-0.89); P < 0.0001] were associated with non-persistent PIRA. Patients with non-persistent PIRA had a hazard ratio of 0.19 [95% confidence interval, (0.15-0.25); P < 0.0001] for reaching EDSS 6 and 0.18 [(0.11-0.29); P < 0.0001] for reaching SPMS compared to patients with persistent PIRA. PIRA events slowly regress in one-third of patients. Patients with persistent PIRA had a substantially higher risk of reaching EDSS 6 and SPMS than those with non-persistent PIRA. Younger age, lower baseline EDSS, and use of high-efficacy DMT during PIRA events were associated with PIRA regression.

• Keywords
• disability improvement, disability progression, progression independent of relapse activity (PIRA), relapsing-remitting multiple sclerosis (RRMS), secondary progressive MS (SPMS),
• Publication type
• Journal Article MeSH

IMPORTANCE: Progression independent of relapse activity (PIRA) is a significant contributor to long-term disability accumulation in relapsing-remitting multiple sclerosis (MS). Prior studies have used varying PIRA definitions, hampering the comparability of study results. OBJECTIVE: To compare various definitions of PIRA. DESIGN, SETTING, AND PARTICIPANTS: This cohort study involved a retrospective analysis of prospectively collected data from the MSBase registry from July 2004 to July 2023. The participants were patients with MS from 186 centers across 43 countries who had clinically definite relapsing-remitting MS, a complete minimal dataset, and 3 or more documented Expanded Disability Status Scale (EDSS) assessments. EXPOSURE: Three-hundred sixty definitions of PIRA as combinations of the following criteria: baseline disability (fixed baseline with re-baselining after PIRA, or plus re-baselining after relapses, or plus re-baselining after improvements), minimum confirmation period (6, 12, or 24 months), confirmation magnitude (EDSS score at/above worsening score or at/above threshold compared with baseline), freedom from relapse at EDSS score worsening (90 days prior, 90 days prior and 30 days after, 180 days prior and after, since previous EDSS assessment, or since baseline), and freedom from relapse at confirmation (30 days prior, 90 days prior, 30 days before and after, or between worsening and confirmation). MAIN OUTCOME AND MEASURE: For each definition, we quantified PIRA incidence and persistence (ie, absence of a 3-month confirmed EDSS improvement over ≥5 years). RESULTS: Among 87 239 patients with MS, 33 303 patients fulfilled the inclusion criteria; 24 152 (72.5%) were female and 9151 (27.5%) were male. At the first visits, the mean (SD) age was 36.4 (10.9) years; 28 052 patients (84.2%) had relapsing-remitting MS, and the median (IQR) EDSS score was 2.0 (1.0-3.0). Participants had a mean (SD) 15.1 (11.9) visits over 8.9 (5.2) years. PIRA incidence ranged from 0.141 to 0.658 events per decade and persistence from 0.753 to 0.919, depending on the definition. In particular, the baseline and confirmation period influenced PIRA detection. The following definition yielded balanced incidence and persistence: a significant disability worsening compared with a baseline (reset after each PIRA event, relapse, and EDSS score improvement), in absence of relapses since the last EDSS assessment, confirmed with EDSS scores (not preceded by relapses within 30 days) that remained above the worsening threshold for at least 12 months. CONCLUSION AND RELEVANCE: Incidence and persistence of PIRA are determined by the definition used. The proposed standardized definition aims to enhance comparability among studies.

• MeSH
• Adult MeSH
• Cohort Studies MeSH
• Middle Aged MeSH
• Humans MeSH
• Disability Evaluation MeSH
• Disease Progression * MeSH
• Recurrence MeSH
• Registries MeSH
• Multiple Sclerosis, Relapsing-Remitting * diagnosis   physiopathology   MeSH
• Retrospective Studies MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

BACKGROUND: Previous studies have indicated that progression independent of relapse activity (PIRA) is uncommon in patients with aquaporin- 4 antibody-positive (AQP4-IgG) neuromyelitis optica spectrum disorder (NMOSD). However, the patterns of disability accumulation in seronegative NMOSD are unknown. This study aimed to evaluate the prevalence of PIRA and relapse-associated worsening (RAW) in seronegative NMOSD. METHODS: We conducted a retrospective, multicentre cohort study of seronegative NMOSD patients from the MSBase registry. Inclusion criteria required at least three recorded expanded disability status scale (EDSS) scores: baseline, progression, and 6 months confirmed disability progression (CDP). For those with 6-month CDP, the presence or absence of relapse between baseline and progression determined the classification as RAW or PIRA, respectively. Descriptive statistics were employed to present the data. RESULTS: This study included 93 patients, with a median follow-up duration of 5.0 years (Q1 2.8, Q3 8.4). The cohort predominantly consisted of female patients (77.4%), with a median age of onset of 33.9 years (Q1 26.1, Q3 41.2). PIRA was observed in 1 case (1.1%), whilst RAW was documented in 7 cases (7.5%). CONCLUSION: This international cohort study confirms that CDP is uncommon in seronegative NMOSD. Given more than three quarters of CDP occur due to RAW, therapeutic strategies should focus primarily on preventing relapses.

• Keywords
• Disability, EDSS, NMOSD, Progression independent of relapses, Relapse-associated worsening, Seronegative,
• MeSH
• Aquaporin 4 immunology   MeSH
• Autoantibodies blood   MeSH
• Adult MeSH
• Cohort Studies MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Follow-Up Studies MeSH
• Neuromyelitis Optica * physiopathology   epidemiology   blood   immunology   MeSH
• Disability Evaluation MeSH
• Disease Progression * MeSH
• Recurrence MeSH
• Registries MeSH
• Retrospective Studies MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Names of Substances
• Aquaporin 4 MeSH
• AQP4 protein, human MeSH Browser
• Autoantibodies MeSH

BACKGROUND: Alemtuzumab (ALEM) is a humanised monoclonal antibody that depletes circulating lymphocytes by selectively targeting CD52, which is expressed in high levels on T- and B-lymphocytes. This depletion is followed by lymphocyte repopulation and a cytokine expression shift towards a lesser inflammatory profile, both of which may contribute to prolonged efficacy. National recommendations for enrolling and treating multiple sclerosis (MS) patients with ALEM have been established. However, there are no recommendations in place for the treatment of MS reactivation after the ALEM treatment. OBJECTIVES: To evaluate the effectiveness and safety of the use of ALEM and to analyse subsequent disease-modifying treatments (DMTs). A multidimensional prediction model was developed to make a patient-specific prognosis regarding the response to ALEM. DESIGN: A multicentre, prospective, non-controlled, non-interventional, observational cohort study. METHODS: Relapsing multiple sclerosis patients (RMSp) who received ⩾1 dose of ALEM were enrolled. In each treatment year, the following baseline and prospective data were collected: age, MS history, number, type and duration of previous disease-modifying treatment (PDMT), relapse rate (REL), expanded disability status scale (EDSS), magnetic resonance imaging and serious adverse events (AE). In cases of reactivation of MS, all data about the subsequent DMT were collected. RESULTS: A total of 142 RMSp from 10 MS Slovak Centres fulfilled the inclusion criteria. The average age was 35 years (standard error 8.56). The overall average EDSS was 3.87 (1.46) when ALEM was started. The average duration of PDMT was 6.0 (4.04) years, and the median number of PDMTs was 3 (0-5), while the patients were mostly treated with 2 or 3 DMTs (>65.00%). Post-ALEM treatment was needed in 39 cases (27.46%). The most frequent post-ALEM treatment indicated was ocrelizumab, followed by natalizumab (NAT), siponimod and cladribine. The ocrelizumab and NAT treatment bring little benefit to patients. Siponimod showed less EDSS increase in contrast to ocrelizumab and NAT. Another repopulation therapy, cladribine, may also be an effective option. Statistically significant predictors for the expected EDSS are age (p-value <0.0001), number of ALEM cycles (0.0066), high number of PDMT (0.0459) and the occurrence of relapses (<0.0001). There was no statistically significant effect on the patient's gender (0.6038), duration of disease-modifying treatment before alemtuzumab (0.4466), or the occurrence of AE (0.6668). CONCLUSION: The study confirms the positive effect of ALEM on clinical and radiological outcomes. We need more data from long-term sequencing studies.

• Keywords
• alemtuzumab, long-term efficacy, long-term safety, multiple sclerosis, post-alemtuzumab treatment, real-world data,
• Publication type
• Journal Article MeSH

Multiple sclerosis is a chronic, inflammatory, and neurodegenerative disease of the central nervous system and a major cause of neurological disability in young adults. Its prevalence and incidence are increasing, and it has been estimated at over 2.8 million cases worldwide, in addition to recent trends towards a shift in MS prevalence to older ages, with peak prevalence estimates in the sixth decade of life. Although historically the relapsing and progressive phases of the disease have been considered separate clinical entities, recent evidence of progression independent of relapse activity (PIRA) has led to a reconsideration of multiple sclerosis as a continuum, in which relapsing and progressive features variably coexist from the earliest stages of the disease, challenging the traditional view of the disease course. In this Series article, we provide an overview of how the traditional description of the clinical course of MS and epidemiological trends in Europe have evolved. For this purpose, we focus on the concept of PIRA, discussing its potential as the main mechanism by which patients acquire disability, how its definition varies between studies, and ongoing research in this field. We emphasise the importance of incorporating the assessment of hidden clinical manifestations into patient management to help uncover and quantify the PIRA phenomenon and the possible implications for future changes in the clinical classification of the disease. At the same time, we provide insights into overcoming the challenges of identifying and defining PIRA and adopting a new understanding of the clinical course of MS.

• Keywords
• Clinical classification, Epidemiology, Multiple sclerosis, Progression idependent of relapse activity,
• Publication type
• Journal Article MeSH
• Review MeSH

Geographical variations in the incidence and prevalence of multiple sclerosis have been reported globally. Latitude as a surrogate for exposure to ultraviolet radiation but also other lifestyle and environmental factors are regarded as drivers of this variation. No previous studies evaluated geographical variation in the risk of secondary progressive multiple sclerosis, an advanced form of multiple sclerosis that is characterized by steady accrual of irreversible disability. We evaluated differences in the risk of secondary progressive multiple sclerosis in relation to latitude and country of residence, modified by high-to-moderate efficacy immunotherapy in a geographically diverse cohort of patients with relapsing-remitting multiple sclerosis. The study included relapsing-remitting multiple sclerosis patients from the global MSBase registry with at least one recorded assessment of disability. Secondary progressive multiple sclerosis was identified as per clinician diagnosis. Sensitivity analyses used the operationalized definition of secondary progressive multiple sclerosis and the Swedish decision tree algorithm. A proportional hazards model was used to estimate the cumulative risk of secondary progressive multiple sclerosis by country of residence (latitude), adjusted for sex, age at disease onset, time from onset to relapsing-remitting phase, disability (Multiple Sclerosis Severity Score) and relapse activity at study inclusion, national multiple sclerosis prevalence, government health expenditure, and proportion of time treated with high-to-moderate efficacy disease-modifying therapy. Geographical variation in time from relapsing-remitting phase to secondary progressive phase of multiple sclerosis was modelled through a proportional hazards model with spatially correlated frailties. We included 51 126 patients (72% female) from 27 countries. The median survival time from relapsing-remitting phase to secondary progressive multiple sclerosis among all patients was 39 (95% confidence interval: 37 to 43) years. Higher latitude [median hazard ratio = 1.21, 95% credible interval (1.16, 1.26)], higher national multiple sclerosis prevalence [1.07 (1.03, 1.11)], male sex [1.30 (1.22, 1.39)], older age at onset [1.35 (1.30, 1.39)], higher disability [2.40 (2.34, 2.47)] and frequent relapses [1.18 (1.15, 1.21)] at inclusion were associated with increased hazard of secondary progressive multiple sclerosis. Higher proportion of time on high-to-moderate efficacy therapy substantially reduced the hazard of secondary progressive multiple sclerosis [0.76 (0.73, 0.79)] and reduced the effect of latitude [interaction: 0.95 (0.92, 0.99)]. At the country-level, patients in Oman, Tunisia, Iran and Canada had higher risks of secondary progressive multiple sclerosis relative to the other studied regions. Higher latitude of residence is associated with a higher probability of developing secondary progressive multiple sclerosis. High-to-moderate efficacy immunotherapy can mitigate some of this geographically co-determined risk.

• Keywords
• disease-modifying therapy, geography, health expenditure, latitude, secondary progressive multiple sclerosis,
• MeSH
• Multiple Sclerosis, Chronic Progressive * epidemiology   MeSH
• Humans MeSH
• Neoplasm Recurrence, Local MeSH
• Disease Progression MeSH
• Multiple Sclerosis, Relapsing-Remitting * epidemiology   MeSH
• Multiple Sclerosis * epidemiology   diagnosis   MeSH
• Ultraviolet Rays MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

INTRODUCTION: Prescribing guidance for disease-modifying treatment (DMT) in multiple sclerosis (MS) is centred on a clinical diagnosis of relapsing-remitting MS (RRMS). DMT prescription guidelines and monitoring vary across countries. Standardising the approach to diagnosis of disease course, for example, assigning RRMS or secondary progressive MS (SPMS) diagnoses, allows examination of the impact of health system characteristics on the stated clinical diagnosis and treatment access. METHODS: We analysed registry data from six cohorts in five countries (Czech Republic, Denmark, Germany, Sweden and United Kingdom) on patients with an initial diagnosis of RRMS. We standardised our approach utilising a pre-existing algorithm (DecisionTree, DT) to determine patient diagnoses of RRMS or secondary progressive MS (SPMS). We identified five global drivers of DMT prescribing: Provision, Availability, Funding, Monitoring and Audit, data were analysed against these concepts using meta-analysis and univariate meta-regression. RESULTS: In 64,235 patients, we found variations in DMT use between countries, with higher usage in RRMS and lower usage in SPMS, with correspondingly lower usage in the UK compared to other registers. Factors such as female gender (p = 0.041), increasing disability via Expanded Disability Status Scale (EDSS) score (p = 0.004), and the presence of monitoring (p = 0.029) in SPMS influenced the likelihood of receiving DMTs. Standardising the diagnosis revealed differences in reclassification rates from clinical RRMS to DT-SPMS, with Sweden having the lowest rate Sweden (Sweden 0.009, range: Denmark 0.103 - UK portal 0.311). Those with higher EDSS at index (p < 0.03) and female gender (p < 0.049) were more likely to be reclassified from RRMS to DT-SPMS. The study also explored the impact of diagnosis on DMT usage in clinical SPMS, finding that the prescribing environment and auditing practices affected access to treatment. DISCUSSION: This highlights the importance of a healthcare system's approach to verifying the clinical label of MS course in facilitating appropriate prescribing, with some flexibility allowed in uncertain cases to ensure continued access to treatment.

• Keywords
• big data, clinical audit, decision tree, disease registers, international collaboration, multiple sclerosis,
• Publication type
• Journal Article MeSH

BACKGROUND AND OBJECTIVES: B cell-depleting antibodies were proven as effective strategy for the treatment of relapsing multiple sclerosis (RMS). The monoclonal antibody ocrelizumab was approved in 2017 in the United States and in 2018 in the European Union, but despite proven efficacy in randomized, controlled clinical trials, its effectiveness in the real-world setting remains to be fully elucidated. In particular, most study patients were treatment naive or switched from injectable therapies, whereas oral substances or monoclonal antibodies made up >1% of previous treatments. METHODS: We evaluated ocrelizumab-treated patients with RMS enrolled in the prospective cohorts at the University Hospitals Duesseldorf and Essen, Germany. Epidemiologic data at baseline were compared, and Cox proportional hazard models were applied to evaluate outcomes. RESULTS: Two hundred eighty patients were included (median age: 37 years, 35% male patients). Compared with using ocrelizumab as a first-line treatment, its use as a third-line therapy increased hazard ratios (HRs) for relapse and disability progression, whereas differences between first- vs second-line and second- vs third-line remained smaller. We stratified patients according to their last previous disease-modifying treatment and here identified fingolimod (FTY) (45 patients, median age 40 years, 33% male patients) as a relevant risk factor for ongoing relapse activity despite 2nd-line (HR: 3.417 [1.007-11.600]) or 3rd-line (HR: 5.903 [2.489-13.999]) ocrelizumab treatment, disability worsening (2nd line: HR: 3.571 [1.013-12.589]; 3rd line: HR: 4.502 [1.728-11.729]), and occurrence of new/enlarging MRI lesions (2nd line: HR: 1.939 [0.604-6.228]; 3rd line: HR: 4.627 [1.982-10.802]). Effects were persistent throughout the whole follow-up. Neither peripheral B-cell repopulation nor immunoglobulin G levels were associated with rekindling disease activity. DISCUSSION: Our prospectively collected observational data suggest suboptimal effectiveness of ocrelizumab in patients switching from FTY compared with those switching from other substances or having been treatment naive. These findings support previous studies indicating abated effectiveness of immune cell-depleting therapies following FTY treatment in patients with RMS. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with RMS, previous treatment with FTY compared with previous treatment with other immunomodulating therapies decreases the effectiveness of ocrelizumab.

• MeSH
• Antilymphocyte Serum MeSH
• Adult MeSH
• Humans MeSH
• Prospective Studies MeSH
• Recurrence MeSH
• Multiple Sclerosis, Relapsing-Remitting * drug therapy   MeSH
• Multiple Sclerosis * drug therapy   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• United States MeSH
• Names of Substances
• Antilymphocyte Serum MeSH
• ocrelizumab MeSH Browser

BACKGROUND: To assign a course of secondary progressive multiple sclerosis (MS) (SPMS) may be difficult and the proportion of persons with SPMS varies between reports. An objective method for disease course classification may give a better estimation of the relative proportions of relapsing-remitting MS (RRMS) and SPMS and may identify situations where SPMS is under reported. MATERIALS AND METHODS: Data were obtained for 61,900 MS patients from MS registries in the Czech Republic, Denmark, Germany, Sweden, and the United Kingdom (UK), including date of birth, sex, SP conversion year, visits with an Expanded Disability Status Scale (EDSS) score, MS onset and diagnosis date, relapses, and disease-modifying treatment (DMT) use. We included RRMS or SPMS patients with at least one visit between January 2017 and December 2019 if ≥ 18 years of age. We applied three objective methods: A set of SPMS clinical trial inclusion criteria ("EXPAND criteria") modified for a real-world evidence setting, a modified version of the MSBase algorithm, and a decision tree-based algorithm recently published. RESULTS: The clinically assigned proportion of SPMS varied from 8.7% (Czechia) to 34.3% (UK). Objective classifiers estimated the proportion of SPMS from 15.1% (Germany by the EXPAND criteria) to 58.0% (UK by the decision tree method). Due to different requirements of number of EDSS scores, classifiers varied in the proportion they were able to classify; from 18% (UK by the MSBase algorithm) to 100% (the decision tree algorithm for all registries). Objectively classified SPMS patients were older, converted to SPMS later, had higher EDSS at index date and higher EDSS at conversion. More objectively classified SPMS were on DMTs compared to the clinically assigned. CONCLUSION: SPMS appears to be systematically underdiagnosed in MS registries. Reclassified patients were more commonly on DMTs.

• Keywords
• Multiple sclerosis, SPMS, disease course, disease-modifying treatments, progression,
• Publication type
• Journal Article MeSH

The objective of this study was to investigate confirmed progression independent of relapse activity in relapsing-remitting multiple sclerosis patients under long-term natalizumab treatment. We performed a retrospective, cross-sectional study of clinical data captured between 1994 and 2019 at two German multiple sclerosis tertiary referral centres. Data files of all relapsing-remitting multiple sclerosis patients treated with natalizumab for ≥24 months were analysed. Confirmed progression independent of relapse activity was defined as ≥12 week confirmed disability progression on a roving Expanded Disability Status Scale reference score by 1 point in patients with an Expanded Disability Status Scale score ≤3 or 0.5 in patients with an Expanded Disability Status Scale score ≥3.5 in the absence of a relapse. Cox proportional hazard models were used to analyse the probability of developing confirmed progression independent of relapse activity depending on both disease and natalizumab treatment duration. Among the 184 patients identified, 44 (24%) developed confirmed progression independent of relapse activity under natalizumab irrespective of the Expanded Disability Status Scale score at natalizumab onset. Time to confirmed progression independent of relapse activity was not affected by Expanded Disability Status Scale at natalizumab onset (categorized by Expanded Disability Status Scale score ≤3.5 versus >3.5) nor by duration of disease nor by duration of therapy. Confirmed progression independent of relapse activity occurred earlier in the disease course in patients with an earlier natalizumab therapy onset with regard to disease duration. A stepwise forward regression analysis revealed disease duration as the main factor for confirmed progression independent of relapse activity development (P = 0.005). Taken together, confirmed progression independent of relapse activity occurs in a substantial proportion of patients on long-term natalizumab treatment and independent of Expanded Disability Status Scale score at natalizumab onset. Our findings suggest that patients who are initiated on natalizumab early during disease course, usually in order to treat an aggressive clinical phenotype, have a higher risk of early confirmed progression independent of relapse activity.

• Keywords
• cPIRA, disease progression, long-term treatment, multiple sclerosis, natalizumab,
• Publication type
• Journal Article MeSH