Assessing the long-term effectiveness of interferon-beta and glatiramer acetate in multiple sclerosis: final 10-year results from the UK multiple sclerosis risk-sharing scheme

Using instrumental variables to correct for bias in real-world cohort studies of the effects of disease-modifying treatment in MS

BACKGROUND

Estimating the effect of disease-modifying treatment of MS in observational studies is impaired by bias from unmeasured confounders, in particular indication bias.

OBJECTIVE

To show how instrumental variables (IVs) reduce bias.

METHODS

All patients with relapsing onset of MS 1996-2010, identified by the nationwide Danish Multiple Sclerosis Registry, were followed from onset. Exposure was treatment index throughout the first 12 years from onset, defined as a cumulative function of months without and with medium- or high-efficacy treatment, and outcomes were hazard ratios (HRs) per unit treatment index for sustained Expanded Disability Scale Score (EDSS) 4 and 6 adjusted for age at onset and sex, without and with an IV. We used the onset cohort (1996-2000; 2001-2005; 2006-2010) as an IV because treatment index increased across the cohorts.

RESULTS

We included 6014 patients. With conventional Cox regression, HRs for EDSS 4 and 6 were 1.15 [95% CI: 1.13-1.18] and 1.17 [1.13-1.20] per unit treatment index. Only with IVs, we confirmed a beneficial effect of treatment with HRs of 0.86 [0.81-0.91] and 0.82 [0.74-0.90].

CONCLUSION

The use of IVs eliminates indication bias and confirms that treatment is effective in delaying disability. IVs could, under some circumstances, be an alternative to marginal structural models.

Association of Very Early Treatment Initiation With the Risk of Long-term Disability in Patients With a First Demyelinating Event

BACKGROUND AND OBJECTIVES

Early treatment is associated with better long-term outcomes in patients with a first demyelinating event and early multiple sclerosis (MS). However, magnetic resonance (MR) findings are not usually integrated to construct propensity scores (PSs) when evaluating outcomes. We assessed the association of receiving very early treatment with the risk of long-term disability including an MR score (MRS) in patients with a first demyelinating event.

METHODS

We included 580 patients with a first demyelinating event prospectively collected between 1994 and 2021, who received at least 1 disease-modifying drug (DMD). Patients were classified into tertiles according to the cohort's distribution of the time from the first demyelinating event to the first DMD: first tertile (FT) or very early treatment (6 months; n = 194), second tertile (6.1-16 months, n = 192), and third tertile (TT) (16.1 months, n = 194). A 5-point MRS was built according to the sum of the following indicators: ≥9 brain lesions (1 point); ≥1 infratentorial lesion (1 point); ≥1 spinal cord (SC) lesion (1 point); ≥1 contrast-enhancing (CE) brain lesion (1 point); and ≥1 CE SC lesion (1 point). PS based on covariates and the MRS was computed for each of the outcomes. Inverse PS-weighted Cox and linear regression models assessed the risk of different outcomes between tertile groups. Finally, to confirm the role of MR in treatment decision, we studied the time elapsed from the first demyelinating event to treatment initiation according to the MRS in all patients with radiologic available information, renamed as raw-MRS.

RESULTS

Very early treatment decreased the risk of reaching Expanded Disability Status Scale 3.0 (hazard ratio [HR] 0.55, 95% CI 0.32-0.97), secondary progressive MS (HR 0.40, 95% CI 0.19-0.85), and sustained disease progression at 12 months after treatment initiation (HR 0.50, 95% CI 0.29-0.84), when compared with patients from the TT group. Patients from the FT group had a lower disability progression rate (β estimate -0.009, 95% CI -0.016 to -0.002) and a lower severe disability measured by the Patient-Determined Disease Step (β estimate -0.52, 95% CI -0.91 to -0.13) than the TT group. Finally, there was a 62.4% reduction in the median time between the first demyelinating event and the first-ever treatment initiation from patients displaying a raw-MRS 1 to patients with a raw-MRS 5.

DISCUSSION

Using PS models with and without MRS, we showed that treatment initiation at very early stages is associated with a reduction in the risk of long-term disability accrual in patients with a first demyelinating event.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that earlier treatment of patients with MS presenting with a first demyelinating event is associated with improved clinical outcomes.

CNS resilience in the progression of MS

Resilience; Progressive multiple sclerosis; Genomics.

Interferon beta-1a sc at 25 years: a mainstay in the treatment of multiple sclerosis over the period of one generation

INTRODUCTION

Interferon beta (IFN beta) preparations are an established group of drugs used for immunomodulation in patients with multiple sclerosis (MS). Subcutaneously (sc) applied interferon beta-1a (IFN beta-1a sc) has been in continuous clinical use for 25 years as a disease-modifying treatment.

AREAS COVERED

Based on data published since 2018, we discuss recent insights from analyses of the pivotal trial PRISMS and its long-term extension as well as from newer randomized studies with IFN beta-1a sc as the reference treatment, the use of IFN beta-1a sc across the patient life span and as a bridging therapy, recent data regarding the mechanisms of action, and potential benefits of IFN beta-1a sc regarding vaccine responses.

EXPERT OPINION

IFN beta-1a sc paved the way to effective immunomodulatory treatment of MS, enabled meaningful insights into the disease process, and remains a valid therapeutic option in selected vulnerable MS patient groups.

Locus for severity implicates CNS resilience in progression of multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) that results in significant neurodegeneration in the majority of those affected and is a common cause of chronic neurological disability in young adults1,2. Here, to provide insight into the potential mechanisms involved in progression, we conducted a genome-wide association study of the age-related MS severity score in 12,584 cases and replicated our findings in a further 9,805 cases. We identified a significant association with rs10191329 in the DYSF-ZNF638 locus, the risk allele of which is associated with a shortening in the median time to requiring a walking aid of a median of 3.7 years in homozygous carriers and with increased brainstem and cortical pathology in brain tissue. We also identified suggestive association with rs149097173 in the DNM3-PIGC locus and significant heritability enrichment in CNS tissues. Mendelian randomization analyses suggested a potential protective role for higher educational attainment. In contrast to immune-driven susceptibility3, these findings suggest a key role for CNS resilience and potentially neurocognitive reserve in determining outcome in MS.

Variability of the response to immunotherapy among subgroups of patients with multiple sclerosis

BACKGROUND AND PURPOSE

This study assessed the effect of patient characteristics on the response to disease-modifying therapy (DMT) in multiple sclerosis (MS).

METHODS

We extracted data from 61,810 patients from 135 centers across 35 countries from the MSBase registry. The selection criteria were: clinically isolated syndrome or definite MS, follow-up ≥ 1 year, and Expanded Disability Status Scale (EDSS) score ≥ 3, with ≥1 score recorded per year. Marginal structural models with interaction terms were used to compare the hazards of 12-month confirmed worsening and improvement of disability, and the incidence of relapses between treated and untreated patients stratified by their characteristics.

RESULTS

Among 24,344 patients with relapsing MS, those on DMTs experienced 48% reduction in relapse incidence (hazard ratio [HR] = 0.52, 95% confidence interval [CI] = 0.45-0.60), 46% lower risk of disability worsening (HR = 0.54, 95% CI = 0.41-0.71), and 32% greater chance of disability improvement (HR = 1.32, 95% CI = 1.09-1.59). The effect of DMTs on EDSS worsening and improvement and the risk of relapses was attenuated with more severe disability. The magnitude of the effect of DMT on suppressing relapses declined with higher prior relapse rate and prior cerebral magnetic resonance imaging activity. We did not find any evidence for the effect of age on the effectiveness of DMT. After inclusion of 1985 participants with progressive MS, the effect of DMT on disability mostly depended on MS phenotype, whereas its effect on relapses was driven mainly by prior relapse activity.

CONCLUSIONS

DMT is generally most effective among patients with lower disability and in relapsing MS phenotypes. There is no evidence of attenuation of the effect of DMT with age.

Contemporary study of multiple sclerosis disability in South East Wales

BACKGROUND

A contemporary understanding of disability evolution in multiple sclerosis (MS) is an essential tool for individual disease management and planning of interventional studies. We have used prospectively collected longitudinal data to analyse disability progression and variation in a British MS cohort.

METHODS

Cox proportional hazards regression was used to estimate hazard of Expanded Disability Status Scale (EDSS) 4.0 and 6.0. A continuous Markov model was used to estimate transitional probabilities for individual EDSS scores. Models were adjusted for age at MS onset, sex and disease-modifying treatments (DMTs) exposure.

RESULTS

2135 patients were included (1487 (70%) female, 1922 (89%) relapsing onset). 865 (41%) had used DMTs. Median time to EDSS 4.0 and 6.0 was 18.2 years (95% CI 16.3 to 20.2) and 22.1 years (95% CI 20.5 to 24.5). In the Markov model, the median time spent at EDSS scores of <6 (0.40-0.98 year) was shorter than the time spent at EDSS scores of ≥6 (0.87-4.11 year). Hazard of change in EDSS was greatest at EDSS scores <6 (HR for increasing EDSS: 1.02-1.33; decreasing EDSS: 0.34-1.27) compared with EDSS scores ≥6 (HR for increasing EDSS: 0.08-0.61; decreasing EDSS: 0.18-0.54).

CONCLUSIONS

These data provide a detailed contemporary model of disability outcomes in a representative population-based MS cohort. They support a trend of increasing time to disability milestones compared with historical reference populations, and document disability variation with the use of transitional matrices. In addition, they provide essential information for patient counselling, clinical trial design, service planning and offer a comparative baseline for assessment of therapeutic interventions.

The current standing of autologous haematopoietic stem cell transplantation for the treatment of multiple sclerosis

Autologous haematopoietic stem cell transplantation (aHSCT) is gaining traction as a valuable treatment option for patients affected by severe multiple sclerosis (MS), particularly the relapsing–remitting form. We describe the current literature in terms of clinical trials, observational and retrospective studies, as well as immune reconstitution following transplantation, with a focus on the conditioning regimens used for transplantation. The evidence base predominantly consists of non-randomised, uncontrolled clinical trials or data from retrospective or observational cohorts, i.e. very few randomised or controlled trials. Most often, intermediate-intensity conditioning regimens are used, with promising results from both myeloablative and lymphoablative strategies, as well as from regimens that are low and high intensity. Efficacy of transplantation, which is likely secondary to immune reconstitution and restored immune tolerance, is, therefore, not clearly dependent on the intensity of the conditioning regimen. However, the conditioning regimen may well influence the immune response to transplantation. Heterogeneity of conditioning regimens among studies hinders synthesis of the articles assessing post-aHSCT immune system changes. Factors associated with better outcomes were lower Kurtzke Expanded Disability Status Scale, relapsing–remitting MS, younger age, and shorter disease duration at baseline, which supports the guidance for patient selection proposed by the European Society for Blood and Marrow Transplantation. Interestingly, promising outcomes were described for patients with secondary progressive MS by some studies, which may be worth taking into account when considering treatment options for patients with active, progressive disease. Of note, a significant proportion of patients develop autoimmune disease following transplantation, with alemtuzumab-containing regimens associated with the highest incidence.

How have Economic Evaluations in Relapsing Multiple Sclerosis Evolved Over Time? A Systematic Literature Review

INTRODUCTION

The introduction of disease-modifying therapies (DMTs) for relapsing multiple sclerosis (RMS) over the last two decades has prompted the economic assessments of these treatments by reimbursement authorities. The aim of this systematic literature review was to evaluate the modeling approach and data sources used in economic evaluations of DMTs for RMS, identify differences and similarities, and explore how economic evaluation models have evolved over time.

METHODS

MEDLINE®, Embase®, and EBM Reviews databases were searched using Ovid® Platform from database inception on 25 December 2019 and subsequently updated on 17 February 2021. In addition, health technology assessment agency websites, key conference proceedings, and gray literature from relevant websites were screened. The quality of included studies was assessed using the Drummond and Philips checklists.

RESULTS

A total 155 publications and 30 Health Technology Assessment (HTA) reports were included. Most of these were cost-utility analysis (73 studies and 25 HTA reports) and funded by medicines manufacturers (n = 65). The top three countries where studies were conducted were the USA (n = 29), the UK (n = 16), and Spain (n = 10). Studies predominantly used Markov cohort models (94 studies; 25 HTAs) structured based on the Expanded Disability Status Scale (EDSS) with 21 health states (20 studies; 12 HTA reports). The London Ontario and British Columbia data sets were commonly used sources for natural history data (n = 33; n = 13). Twelve studies and ten HTAs from the UK assumed a waning of DMT effect over the long term, while this was uncommon in studies from other countries. Nineteen studies adjusted for multiple sclerosis (MS)-specific mortality estimates, while 18 studies used data from the national life table without adjustment. Studies prominently referred to mortality data that were about two decades old. The data on treatment effect was generally obtained from randomized controlled trials (43 studies; 7 HTAs) or from published evidence synthesis (23 studies; 24 HTAs). Utility estimates were derived from either published studies and/or supplemented with data from RCTs. Most of the models used the lifetime horizon (n = 37) with a 1-year cycle length (n = 63).

CONCLUSION

As expected, similarities as well as differences were observed across the different economic models. Available evidence suggests models should continue using the Markov cohort model with 21 EDSS-based states, however, allowing the transition to a lower EDSS state and assuming a sustained treatment effect. With reference to the data sources, models should consider using a contemporary MS-specific mortality data, recent natural history data, and country-specific utility data if available. In case of data unavailability, a sensitivity analysis using multiple sources of data should be conducted. In addition, future models should incorporate other clinically relevant outcomes, such as the cognition, vision, and psychological aspects of RMS, to be able to present the comprehensive value of DMTs.

Apparent changes in the epidemiology and severity of multiple sclerosis

Multiple sclerosis (MS) is an immunological disease that causes acute inflammatory lesions and chronic inflammation in the CNS, leading to tissue damage and disability. As awareness of MS has increased and options for therapy have come into use, a large amount of epidemiological data have been collected, enabling studies of changes in incidence and disease course over time. Overall, these data seem to indicate that the incidence of MS has increased, but the course of the disease has become milder, particularly in the 25 years since the first disease-modifying therapies (DMTs) became available. A clear understanding of these trends and the reasons for them is important for understanding the factors that influence the development and progression of MS, and for clinical management with respect to prevention and treatment decisions. In this Review, we consider the evidence for changes in the epidemiology of MS, focusing on trends in the incidence of the disease over time and trends in the disease severity. In addition, we discuss the factors influencing these trends, including refinement of diagnostic criteria and improvements in health-care systems that have increased diagnosis in people with mild disease, and the introduction and improvement of DMT.

A systematic, concept-based method of developing the exposure measure for drug safety and effectiveness studies

PURPOSE

In drug safety and effectiveness studies based on secondary data, the choice of an appropriate exposure measure for a given outcome can be challenging. Different measures of exposure can yield different estimates of treatment effect and safety. There is a knowledge gap with respect to developing and refining measures of drug exposure, to ensure that the exposure measure addresses the study question and is suitable for statistical analysis.

METHODS

We present a transparent, step-by-step approach to the development of drug exposure measures involving secondary data. This approach would be of interest to students and investigators with initial training in pharmacoepidemiology. We illustrate the approach using a study about Parkinson's disease.

RESULTS

We described the exposure specifications according to the study question. Next, we refined the exposure measure by linking it to knowledge about four major concepts in drug safety and effectiveness studies: drug use patterns, duration, timing, and dose. We then used this knowledge to guide the ultimate choice of exposure measure: time-varying, cumulative 6-month exposure to tamsulosin (a drug used to treat prostate hyperplasia).

CONCLUSIONS

The proposed approach links exposure specifications to four major concepts in drug safety and effectiveness studies. Formulating subject-matter knowledge about these major concepts provides an avenue to develop the rationale and specifications for the exposure measure.

Impact of drug diversity on treatment effectiveness in relapsing-remitting multiple sclerosis (RRMS) in Germany between 2010 and 2018: real-world data from the German NeuroTransData multiple sclerosis registry

OBJECTIVE

To evaluate the impact of drug diversity on treatment effectiveness in relapsing-remitting multiple sclerosis (RRMS) in Germany.

DESIGN

This study employs real-world data captured in-time during clinical visits in 67 German neurology outpatient offices of the NeuroTransData (NTD) multiple sclerosis (MS) registry between 1 January 2010 and 30 June 2019, including 237 976 visits of 17 553 patients with RRMS. Adherence and clinical effectiveness parameters were analysed by descriptive statistics, time-to-event analysis overall and by disease-modifying therapies (DMTs) stratified by administration modes (injectable, oral and infusion). Three time periods were compared: 2010-2012, 2013-2015 and 2016-2018.

RESULTS

Between 2010 and 2018, an increasing proportion of patients with RRMS were treated with DMTs and treatment was initiated sooner after diagnosis of MS. Introduction of oral DMT temporarily induced higher readiness to switch. Comparing the three index periods, there was a continuous decrease of annualised relapse rates, less frequent Expanded Disability Status Scale (EDSS) progression and increasing periods without relapse, EDSS worsening and with stability of no-evidence-of-disease-activity 2 and 3 criteria, lower conversion rates to secondary progressive MS on oral and on injectable DMTs.

CONCLUSION

Sparked by the availability of new mainly oral DMTs, RRMS treatment effectiveness improved clinically meaningful between 2010 and 2018. As similar effects were seen for injectable and oral DMTs more than for infusions, a better personalised treatment allocation in many patients is likely. These results indicate that there is an overall beneficial effect for the whole patient with MS population as a result of the greater selection of available DMTs, a benefit beyond the head-to-head comparative efficacy, resulting from an increased probability and readiness to individualise MS therapy.

Pathology-supported genetic testing as a method for disability prevention in multiple sclerosis (MS). Part I. Targeting a metabolic model rather than autoimmunity

In this Review (Part I), we investigate the scientific evidence that multiple sclerosis (MS) is caused by the death of oligodendrocytes, the cells that synthesize myelin, due to a lack of biochemical and nutritional factors involved in mitochondrial energy production in these cells. In MS, damage to the myelin sheaths surrounding nerve axons causes disruption of signal transmission from the brain to peripheral organs, which may lead to disability. However, the extent of disability is not deterred by the use of MS medication, which is based on the autoimmune hypothesis of MS. Rather, disability is associated with the loss of brain volume, which is related to the loss of grey and white matter. A pathology-supported genetic testing (PSGT) method, developed for personalized assessment and treatment to prevent brain volume loss and disability progression in MS is discussed. This involves identification of MS-related pathogenic pathways underpinned by genetic variation and lifestyle risk factors that may converge into biochemical abnormalities associated with adverse expanded disability status scale (EDSS) outcomes and magnetic resonance imaging (MRI) findings during patient follow-up. A Metabolic Model is presented which hypothesizes that disability may be prevented or reversed when oligodendrocytes are protected by nutritional reserve. Evidence for the validity of the Metabolic Model may be evaluated in consecutive test cases following the PSGT method. In Part II of this Review, two cases are presented that describe the PSGT procedures and the clinical outcomes of these individuals diagnosed with MS.

Altered Immune Phenotypes and HLA-DQB1 Gene Variation in Multiple Sclerosis Patients Failing Interferon β Treatment

Background

Interferon beta (IFNβ) has been prescribed as a first-line disease-modifying therapy for relapsing-remitting multiple sclerosis (RRMS) for nearly three decades. However, there is still a lack of treatment response markers that correlate with the clinical outcome of patients.

Aim

To determine a combination of cellular and molecular blood signatures associated with the efficacy of IFNβ treatment using an integrated approach.

Methods

The immune status of 40 RRMS patients, 15 of whom were untreated and 25 that received IFNβ1a treatment (15 responders, 10 non-responders), was investigated by phenotyping regulatory CD4⁺ T cells and naïve/memory T cell subsets, by measurement of circulating IFNα/β proteins with digital ELISA (Simoa) and analysis of ~600 immune related genes including 159 interferon-stimulated genes (ISGs) with the Nanostring technology. The potential impact of HLA class II gene variation in treatment responsiveness was investigated by genotyping HLA-DRB1, -DRB3,4,5, -DQA1, and -DQB1, using as a control population the Milieu Interieur cohort of 1,000 French healthy donors.

Results

Clinical responders and non-responders displayed similar plasma levels of IFNβ and similar ISG profiles. However, non-responders mainly differed from other subject groups with reduced circulating naïve regulatory T cells, enhanced terminally differentiated effector memory CD4⁺ T_EMRA cells, and altered expression of at least six genes with immunoregulatory function. Moreover, non-responders were enriched for HLA-DQB1 genotypes encoding DQ8 and DQ2 serotypes. Interestingly, these two serotypes are associated with type 1 diabetes and celiac disease. Overall, the immune signatures of non-responders suggest an active disease that is resistant to therapeutic IFNβ, and in which CD4⁺ T cells, likely restricted by DQ8 and/or DQ2, exert enhanced autoreactive and bystander inflammatory activities.

Early treatment delays long-term disability accrual in RRMS: Results from the BMSD network

BACKGROUND

The optimal timing of treatment starts for achieving the best control on the long-term disability accumulation in multiple sclerosis (MS) is still to be defined.

OBJECTIVE

The aim of this study was to estimate the optimal time to start disease-modifying therapies (DMTs) to prevent the long-term disability accumulation in MS, using a pooled dataset from the Big Multiple Sclerosis Data (BMSD) network.

METHODS

Multivariable Cox regression models adjusted for the time to first treatment start from disease onset (in quintiles) were used. To mitigate the impact of potential biases, a set of pairwise propensity score (PS)-matched analyses were performed. The first quintile, including patients treated within 1.2 years from onset, was used as reference.

RESULTS

A cohort of 11,871 patients (median follow-up after treatment start: 13.2 years) was analyzed. A 3- and 12-month confirmed disability worsening event and irreversible Expanded Disability Status Scale (EDSS) 4.0 and 6.0 scores were reached by 7062 (59.5%), 4138 (34.9%), 3209 (31.1%), and 1909 (16.5%) patients, respectively. The risk of reaching all the disability outcomes was significantly lower (p < 0.0004) for the first quintile patients' group.

CONCLUSION

Real-world data from the BMSD demonstrate that DMTs should be commenced within 1.2 years from the disease onset to reduce the risk of disability accumulation over the long term.

Health care resource utilization and disease modifying treatment use in multiple sclerosis patients by age and insurance type

OBJECTIVE

The objective of this study was to describe and compare health care resource utilization (HCRU) and disease modifying treatment (DMT) use among US adults <65 years with multiple sclerosis (MS), across commercial and Medicare Advantage plans.

METHODS

Medical and pharmacy claims data from commercial and Medicare Advantage with Part D (MAPD) plans were extracted for MS patients age 18 - 64 identified between 1 January 2014 and 31 May 2017. Comparisons were made between commercial and MAPD enrollees for all-cause HCRU and DMT use over 1 year, overall and by 5 year age groups.

RESULTS

A total of 28,427 MS patients were identified; two-thirds (67%) had commercial coverage. MAPD patients had statistically significantly higher mean counts of all-cause inpatient, emergency room (ER) and ambulatory visits compared to commercial patients. The significant differences were evident in all age groups ≥30 years, except for ER visits in the 40-44 and 60-64 age groups. MAPD patients had statistically significantly lower prevalence of DMT use compared to commercial patients in all age groups starting at ≥35 years.

CONCLUSION

MAPD patients had a higher burden of medical HCRU compared to their commercially insured counterparts, most likely due primarily to their more advanced disease state and higher level of MS-related disability. Reasons for lower prevalence of DMT use among MAPD patients may include their more advanced disease state, older age and higher prevalence of comorbid conditions compared with commercially insured patients, as well as more restrictive formularies for MAPD vs. commercial plans. These findings suggest that there may be an opportunity for recently approved DMTs indicated for active secondary progressive MS to fulfill an unmet need for treatment among MS patients <65 years without contraindicated comorbid conditions who are enrolled in MAPD plans. Novel therapies under development to delay progression may help keep MS patients of working age in the work force.

Profiling serum neurofilament light chain and glial fibrillary acidic protein in primary progressive multiple sclerosis

This study examined the utility of serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) as biomarkers in primary progressive multiple sclerosis in context with clinical severity, progression, and treatment. Using a single-molecule array (Quanterix), serum protein concentrations were measured from twenty-five participants semiannually for five years. There was no association between levels of either biomarker and disease severity, disease duration, or treatment group. Enrollment sNfL level was not associated with future clinical worsening. Precedent clinical worsening was not associated with last sGFAP measurement. These results suggest a limited role for these biomarkers in primary progressive disease management.

Methodological issues in economic evaluations of emergency transport systems in low-income and middle-income countries

A recent systematic review identified few papers on the economic evaluation of systems for emergency transport of acutely ill or injured patients. In addition, we found no articles dealing with the methodological challenges posed by such studies in low-income or middle-income countries. We therefore carried out an analysis of issues that are of particular salience to this important topic. This is an intellectual study in which we develop models, identify their limitations, suggest potential extensions to the models and discuss priorities for empirical studies to populate models. First, we develop a general model to calculate changes in survival contingent on the reduced time to treatment that an emergency transport system is designed to achieve. Second, we develop a model to estimate transfer times over an area that will be served by a proposed transfer system. Third, we discuss difficulties in obtaining parameters with which to populate the models. Fourth, we discuss costs, both direct and indirect, of an emergency transfer service. Fifth, we discuss the issue that outcomes other than survival should be considered and that the effects of a service are a weighted sum over all the conditions and severities for which the service caters. Lastly, based on the above work, we identify priorities for research. To our knowledge, this is the first study to identify and frame issues in the health economics of acute transfer systems and to develop models to calculate survival rates from basic parameters, such as time delay/survival relationships, that vary by intervention type and context.

Effect of Disease-Modifying Therapy on Disability in Relapsing-Remitting Multiple Sclerosis Over 15 Years

OBJECTIVE

To test the hypothesis that immunotherapy prevents long-term disability in relapsing-remitting multiple sclerosis (MS), we modeled disability outcomes in 14,717 patients.

METHODS

We studied patients from MSBase followed for ≥1 year, with ≥3 visits, ≥1 visit per year, and exposed to MS therapy, and a subset of patients with ≥15-year follow-up. Marginal structural models were used to compare the cumulative hazards of 12-month confirmed increase and decrease in disability, Expanded Disability Status Scale (EDSS) step 6, and the incidence of relapses between treated and untreated periods. Marginal structural models were continuously readjusted for patient age, sex, pregnancy, date, disease course, time from first symptom, prior relapse history, disability, and MRI activity.

RESULTS

A total of 14,717 patients were studied. During the treated periods, patients were less likely to experience relapses (hazard ratio 0.60, 95% confidence interval [CI] 0.43-0.82, p = 0.0016), worsening of disability (0.56, 0.38-0.82, p = 0.0026), and progress to EDSS step 6 (0.33, 0.19-0.59, p = 0.00019). Among 1,085 patients with ≥15-year follow-up, the treated patients were less likely to experience relapses (0.59, 0.50-0.70, p = 10^-9) and worsening of disability (0.81, 0.67-0.99, p = 0.043).

CONCLUSION

Continued treatment with MS immunotherapies reduces disability accrual by 19%-44% (95% CI 1%-62%), the risk of need of a walking aid by 67% (95% CI 41%-81%), and the frequency of relapses by 40-41% (95% CI 18%-57%) over 15 years. This study provides evidence that disease-modifying therapies are effective in improving disability outcomes in relapsing-remitting MS over the long term.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that, for patients with relapsing-remitting MS, long-term exposure to immunotherapy prevents neurologic disability.

The course of multiple sclerosis rewritten: a Norwegian population-based study on disease demographics and progression

OBJECTIVES

Over the past few decades, there has been an improvement in the rate of disability progression in multiple sclerosis (MS) patients, and most studies relate this evolvement to the introduction of disease-modifying therapies. However, several other factors have changed over this period, including access to MRI and newer diagnostic criteria. The aim of this study is to investigate changes in the natural course of MS over time in a near-complete and geographically well-defined population from the south-east of Norway.

METHODS

We examined disease progression and demographics over two decades and assessed the effect of disease-modifying therapies using linear mixed-effect models.

RESULTS

In a cohort of 2097 patients, we found a significant improvement in disability as measured by the Expanded Disability Status Scale (EDSS) stratified by age, and the improvement remained significant after adjusting for time on disease-modifying medications, gender and progressive MS at onset. The time from disease onset to EDSS 6 in the total cohort was 29.8 years (95% CI 28.5-31.1) and was significantly longer in patients diagnosed after 2006 compared to patients diagnosed before. There are significant differences between patient demographics, as well as time to EDSS 6, in the near-complete, geographically well-defined population compared to an additional cohort from the capital Oslo and its suburbs.

CONCLUSION

The natural course of MS is improving, but the improvement seen in disease progression has multifaceted explanations. Our study underlines the importance of completeness of data, relevant timeframes and demographics when comparing different MS populations. Studies on incomplete populations should be interpreted with caution.

Internuclear Ophthalmoplegia as the First Manifestation of Pediatric-Onset Multiple Sclerosis and Concurrent Lyme Disease

BACKGROUND Internuclear ophthalmoplegia (INO) presents as a disruption of horizontal conjugate ocular movement and is an uncommon finding in the pediatric population. Its presence warrants a thorough evaluation to search for demyelinating, mass effect, inflammatory, or infectious etiologies. CASE REPORT A 15-year-old African American girl presented to the Emergency Department with acute horizontal binocular diplopia in left gaze. An ophthalmic examination revealed a right INO. She denied any fever, chills, or neck stiffness. Complete blood counts and a metabolic panel were unremarkable. Magnetic resonance imaging (MRI) of the brain and orbits revealed scattered pontine, periventricular, and subcortical white matter signal abnormalities within the left frontal lobe suggestive of active demyelination. MRI of the spinal column also demonstrated multiple areas of increased signal intensity from the C3 to C7-T1 region. Inflammatory and autoimmune studies were negative. However, her serum IgM and IgG studies were positive for Borrelia burgdorferi with negative CSF titers. Cerebrospinal fluid (CSF) analysis demonstrated mildly elevated glucose (82 mg/dL) and oligoclonal bands, but was otherwise unremarkable. She was started on intravenous methylprednisolone and ceftriaxone. She was subsequently diagnosed with pediatric-onset multiple sclerosis and started on disease-modifying therapy, with full resolution of diplopia and INO 2 weeks later. CONCLUSIONS We present a case of INO presenting as the first manifestation of multiple sclerosis in a pediatric patient with a concurrent infectious etiology. A thorough evaluation can lead to earlier identification and treatment of underlying diseases.

International experience with performance-based risk-sharing arrangements: implications for the Chinese innovative pharmaceutical market

OBJECTIVES

Various forms of outcomes-based or risk-sharing agreements have been implemented since early 2000s as a way of access to innovative medicinal products. This study aims to summarize the international experience of performance-based risk-sharing arrangements (PBRSAs) and identify the preconditions for a successful implementation of such schemes. Their implications for the Chinese healthcare market are discussed.

METHODS

A systematic literature review (in PubMed) was conducted to review the evidence on the nature and performance of PBRSAs in the past 10 years. Grey literature was searched for reports in government websites of the countries in scope.

RESULTS

The search identifies 463 records from PubMed and 3 additional records from other sources. Thirty-one publications are included in the final review. The following preconditions were identified to support a successful implementation of PBRSAs: (1) Identify meaningful and feasible outcome measurements; (2) Establish an effective and efficient data collection infrastructure; (3) Control of the implementation costs; (4) Develop governance and administrative infrastructure to allow delisting and rebate/refund; (5) Clarify personal data protection issues.

CONCLUSIONS

The implementation of PBRSAs has proven to be challenging. Although the Chinese healthcare system is not yet well equipped to implement such schemes, some recent changes may pave the way to successful PBRSAs for particular innovative products.

Informing Medication Discontinuation Decisions among Older Adults with Relapsing-Onset Multiple Sclerosis

BACKGROUND

For older adults with relapsing-onset multiple sclerosis (MS), limited information is available to inform if, or when, disease-modifying drugs (DMDs) may be safely discontinued.

OBJECTIVE

The aim of this study was to project the outcomes of DMD discontinuation among older adults with relapsing-onset MS.

METHODS

We projected the 10-year outcomes of discontinuation of a DMD (interferon-β, fingolimod, or natalizumab) among older adults (aged 55 or 70 years) who were relapse-free for 5 or more years and had not reached an Expanded Disability Status Scale (EDSS) score of 6. Outcomes included the percentage of people who had at least one relapse or reached EDSS 6, and quality-adjusted life-years (QALYs), which incorporated both relapses and disability. We used a simulation modeling approach. With increased age, relapses decreased and the effectiveness of DMDs for disability outcomes also decreased.

RESULTS

We found lower projected benefits for DMD continuation at 70 years of age than at 55 years of age. Compared with discontinuation, the projected benefit of DMD continuation ranged from 0.007 to 0.017 QALYs at 55 years of age and dropped to 0.002-0.006 at 70 years of age. The annual projected benefits of DMD continuation (0.1-3.0 quality-adjusted life-days) were very low compared with typical patient preferences regarding treatment burden.

CONCLUSION

The benefits of DMDs may not be substantial among older adults with relapsing-onset MS. Direct clinical evidence remains limited and the decision of whether to discontinue a DMD should also take into account patient preferences. It is important to gain a better understanding of how age-related changes in the trajectory of relapsing-onset MS affect treatment effectiveness among older adults.

Do disease-modifying drugs (DMD) have a positive impact on the occurrence of secondary progressive multiple sclerosis? Comment

Very recent data from cohorts, such as that of the French Observatory of Multiple Sclerosis (OFSEP) and the MSBase cohort, are the subject of new statistical analyses using propensity scores that enable the matching of relapses frequency, EDSS, age, and sex ratio in patient populations for comparisons with each other, which reduces selection biases. The first data from these cohorts revealed a decline in transition to secondary progressive MS with the most effective disease-modifying drugs currently available, especially when these drugs were used early in the disease. However, these studies remain limited regarding the number of patients, the duration of follow-up, the use of imperfect methodologies, and the level of evidence remains low. The Gothenburg cohort in Sweden, which has been followed since the 1950s, found that 14% of benign non-progressive multiple sclerosis (MS) never evolved to secondary progression after more than 45 years of evolution. EDSS 7 was reached after 48 years of disease (median), and 50% evolved to secondary progressive MS after 15 years (consistent with data from the historic London, Ontario cohort). These data demonstrate that most people living with MS evolve without treatment to a significant long-term disability and that this evolution is closely linked to secondary progression (more than the relapse frequency). Benign forms appear as MS that never passes into secondary progressive MS. Recent data demonstrate that the delay until transition to secondary progression (more than 30 years in the MSBase cohort) and the delay in reaching EDSS 6 decreased since the introduction of disease-modifying drugs 20 years ago. However, randomized placebo-controlled trials do not last more than 2 or 3 years, and many biases may be involved in long-term follow-up studies: worsening patients who are lost to follow-up ("informative censoring" bias: only good responders to treatment remain primarily under the same long-term treatment and are followed); changes in the populations in the most recent studies with a lower rate of relapse and lower progression of disability at the beginning of the disease prior to initiating treatments; and environmental changes that remain largely misunderstood and may contribute to a natural evolution towards less severe disease.

Managed Entry Agreements: Policy Analysis From the European Perspective

BACKGROUND

Mounting pressures on the healthcare system, such as budget constraints and new, costly health technologies reaching the market, have pushed payers and manufacturers to engage in managed entry agreements (MEAs) to address uncertainty and facilitate market access.

OBJECTIVES

This study was conducted to illustrate the current landscape of MEAs in Europe and to analyze the main hurdles they face in implementation, providing a policy perspective.

METHODS

We conducted a health policy analysis based on a literature review and described the emergence, classification, current use, and implementation obstacles of MEAs in Europe.

RESULTS

Throughout Europe, uncertainty and high prices of health technologies have pushed stakeholders towards MEAs. Two main types of MEAs were applied heavily, finance-based agreements (FBAs) and performance-based agreements, including individual performance-based agreements and coverage with evidence development (CED). Service-based agreements have not been as heavily considered so far, yet are increasingly used. Many European countries are turning to CEDs to address uncertainty and facilitate market access while negotiating the pricing and reimbursement rates of products. Despite the interest in CEDs, European countries have moved toward FBAs due to the complexities and burdens associated with PBAs.

CONCLUSIONS

Ultimately, in Europe, with the exception of Italy, where MEAs have proven to be inefficient, MEAs are predominantly FBAs dedicated to addressing cost containment from payers' perspective and external reference pricing from the manufacturers' perspective. It has been speculated that MEAs will disappear in the medium-term as they are counterproductive for extending patient access and emergence of innovation. To inform value-based decision making and allow early access to innovative medicines, CEDs should be revisited.

Glatiramer acetate as a clinically and cost-effective treatment of relapsing multiple sclerosis over 10 years of use within the National Health Service: Final results from the UK Risk Sharing Scheme

Background

The UK Risk Sharing Scheme (RSS) provided information on the effect of first-line multiple sclerosis (MS) disease-modifying treatments on long-term disability.

Objective

The aim is to provide results specific to glatiramer acetate (GA; Copaxone®) from the final 10-year analysis of the RSS.

Methods

A Markov model was used to assess clinical effectiveness measured as Expanded Disability Status Scale (EDSS) progression and utility loss. Untreated patients from the British Columbia MS cohort (1980-1995) were used as a 'virtual comparator' group. A separate Markov model assessed cost-effectiveness, based on a 50-year time horizon (with a 50% treatment waning effect imposed at 10 years) and using NHS list price (£513.95 per 28 days). Results were expressed in quality-adjusted life years (QALYs).

Results

In total, 755 patients with relapsing-remitting MS (RRMS) received GA, with a mean follow-up of 7.1 (standard deviation 1.3) years. EDSS progression was reduced by 23% (progression ratio 76.7, 95% confidence interval [CI] 69.0-84.3) and utility loss by 39% (progression ratio 61.0, 95% CI 52.7-69.3) compared with no treatment. There was no persistent waning in GA treatment effect over time (EDSS: p = 0.093; utilities: p = 0.119). The cost per QALY was £17,841.

Conclusion

GA had a beneficial effect on long-term disability and was a cost-effective treatment for RRMS.

The effectiveness of interferon beta versus glatiramer acetate and natalizumab versus fingolimod in a Polish real-world population

Objective

The aim of the study was to assess the effectiveness of disease-modifying therapies (DMTs) in relapsing-remitting multiple sclerosis (RRMS) patients treated in MS centres in Poland.

Methods

Demographic and clinical data of all Polish RRMS patients receiving DMTs were prospectively collected from 2014 to 2018 in electronic files using the Therapeutic Program Monitoring System (SMPT).

Results

The study included 10,764 RRMS patients treated with DMTs in first-line and 1,042 in second-line programmes. IFNβ more effectively lengthened the times to the first relapse, disability progression, and brain MRI activity than GA. After 2 and 4 years of follow-up, more patients on IFNβ showed no evidence of disease activity (NEDA-3) in comparison to GA (66.3% and 44.3% vs 55.2% and 33.2%, respectively; p<0.001). NAT more effectively reduced brain MRI activity than FTY (p = 0.001). More patients under NAT had NEDA-3 after 2 and 4 years of follow-up compared to FTY (66.2% and 42.1% vs 52.1% and 29.5%, respectively; p = 0.03). In adjusted analysis, a higher baseline Expanded Disability Status Score (EDSS) was a predictor of relapse (p<0.001) and NEDA-3 failure (p = 0.003).

Conclusion

IFNβ compared to GA and NAT compared to FTY more effectively reduced disease activity in a Polish population of RRMS patients.

Interferon Beta-1b for the Treatment of Multiple Sclerosis – More than 10 Years of Experience

Objective: Interferon beta-1b (IFNβ-1b) was the first disease-modifying agent (DMT) used for the treatment of multiple sclerosis (MS). We aimed to evaluate the first patients with MS that started treatment in our clinic.

Methods: An observational, retrospective study was performed on 78 patients that had continuous treatment with IFNβ-1b for more than 10 years. The collection of the demographical data and periodical clinical evaluation was performed on all patients. The disability was quantified using the Expanded Disability Status Scale (EDSS), creating two groups of patients, G1: EDSS < 4.0 and G2: EDSS ≥ 4.0. The hallmarks of the disability evolution were gathered by direct patient interview, such as the symptoms at onset and relapse frequency.

Results: After more than 17 years of disease evolution, more than half (65.38%) of the patients present a mild disability score. The majority (54.90%) started treatment in the first three years after the onset, while the patients in G2 started treatment after more than 3 years from the onset. The initiation of IFNβ-1b lead to a significant reduction of the relapse rates. A reduced number of patients (<25%) transitioned from RRMS to SPMS.

Discussion: Continuous evaluation of MS patients allows us to assess the possibility of prolonged treatment with IFNβ-1b and to differentiate the responders from non-responders. The clear reduction in relapse rates and disability progression, notably in patients that started treatment early ensure us into continuing administering this medication. Compared to historical cohorts, our lot had a slower disability evolution and a significant proportion hadn’t reach an important disability score.