Voxel-wise magnetization transfer imaging study of effects of natalizumab and IFNβ-1a in multiple sclerosis

Advanced MRI Techniques: Diagnosis and Follow-Up of Multiple Sclerosis

Brain and spinal cord imaging plays a pivotal role in aiding clinicians with the diagnosis and monitoring of multiple sclerosis. Nevertheless, the significance of magnetic resonance imaging in MS extends beyond its clinical utility. Advanced imaging modalities have facilitated the in vivo detection of various components of MS pathogenesis, and, in recent years, MRI biomarkers have been utilized to assess the response of patients with relapsing-remitting MS to the available treatments. Similarly, MRI indicators of neurodegeneration demonstrate potential as primary and secondary endpoints in clinical trials targeting progressive phenotypes. This review aims to provide an overview of the latest advancements in brain and spinal cord neuroimaging in MS.

Drug-Induced Progressive Multifocal Leukoencephalopathy (PML): A Systematic Review and Meta-Analysis

INTRODUCTION

Progressive multifocal leukoencephalopathy (PML) was first described among patients affected by hematological or solid tumors. Following the human immunodeficiency virus (HIV) epidemic, people living with HIV have represented most cases for more than a decade. With the diffusion of highly active antiretroviral therapy, this group progressively decreased in favor of patients undergoing treatment with targeted therapy/immunomodulators. In this systematic review and meta-analysis, the objective was to assess which drugs are most frequently related to PML development, and report the incidence of drug-induced PML through a meta-analytic approach.

METHODS

The electronic databases MEDLINE, EMBASE, ClinicalTrials.gov, Web of Science and the Canadian Agency for Drugs and Technologies in Health Database (CADTH) were searched up to May 10, 2022. Articles that reported the risk of PML development after treatment with immunomodulatory drugs, including patients of both sexes under the age of 80 years, affected by any pathology except HIV, primary immunodeficiencies or malignancies, were included in the review. The incidence of drug-induced PML was calculated based on PML cases and total number of patients observed per 100 persons and the observation time. Random-effect metanalyses were conducted for each drug reporting pooled incidence with 95% confidence intervals (CI) and median (interquartile range [IQR]) of the observation time. Heterogeneity was measured by I2 statistics. Publication bias was examined through funnel plots and Egger's test.

RESULTS

A total of 103 studies were included in the systematic review. In our analysis, we found no includible study reporting cases of PML during the course of treatment with ocrelizumab, vedolizumab, abrilumab, ontamalimab, teriflunomide, daclizumab, inebilizumab, basiliximab, tacrolimus, belimumab, infliximab, firategrast, disulone, azathioprine or danazole. Dalfampridine, glatiramer acetate, dimethyl fumarate and fingolimod show a relatively safe profile, although some cases of PML have been reported. The meta-analysis showed an incidence of PML cases among patients undergoing rituximab treatment for multiple sclerosis (MS) of 0.01 cases/100 persons (95% CI - 0.08 to 0.09; I2 = 20.4%; p = 0.25) for a median observation period of 23.5 months (IQR 22.1-42.1). Treatment of MS with natalizumab carried a PML risk of 0.33 cases/100 persons (95% CI 0.29-0.37; I2 = 50%; p = 0.003) for a median observation period of 44.1 months (IQR 28.4-60) and a mean number of doses of 36.3 (standard deviation [SD] ± 20.7). When comparing data about patients treated with standard interval dosing (SID) and extended interval dosing (EID), the latter appears to carry a smaller risk of PML, that is, 0.08 cases/100 persons (95% CI 0.0-0.15) for EID versus 0.3 cases/100 persons (95% CI 0.25-0.34) for SID.

CONCLUSIONS

A higher risk of drug-related PML in patients whose immune system is not additionally depressed by means of neoplasms, HIV or concomitant medications is found in the neurological field. This risk is higher in MS treatment, and specifically during long-term natalizumab therapy. While this drug is still routinely prescribed in this field, considering the efficacy in reducing MS relapses, in other areas it could play a smaller role, and be gradually replaced by other safer and more recently approved agents.

Intravenous or subcutaneous natalizumab in patients with relapsing-remitting multiple sclerosis: investigation on efficiency and savings-the EASIER study

INTRODUCTION

EASIER is a multicenter, observational, cross-sectional study investigating the consumption of healthcare resources, including healthcare professional (HCP) active working time, the costs associated with the current natalizumab intravenous (IV) administration, and the potential impact of the adoption of subcutaneous (SC) route.

METHODS

The EASIER study has three parts: (1) time and motion study to measure healthcare resources and working time needed for natalizumab IV administration using a digital data collection tool operated directly by HCPs; (2) HCP structured questionnaire-based estimation of the potential impact of natalizumab SC vs. IV administration; and (3) patient survey on the burden of natalizumab administration.

RESULTS

Nine Italian multiple sclerosis (MS) centers measured 404 IV natalizumab administration procedures and administered 26 HCP questionnaires and 297 patient questionnaires. Patients had a mean of 52 (range 1-176) previous IV administrations and spent a mean (median, IQR) of 152 (130, 94-184) minutes in the center per each IV procedure, with IV infusion covering 50% of the total. Including patient travel time, an average of 5 h was dedicated to each IV administration. Active working time by HCP amounted to 29 min per IV administration procedure, 70% of which by nursing staff. With adoption of the SC route, HCPs estimated a 50% reduction in patient procedure time and 55% lower HCP active working time. This translated into a 63% cost reduction for the MS center per natalizumab administration procedure.

CONCLUSIONS

SC natalizumab administration will consistently reduce consumption of patient and HCP times per procedure and associated costs.

Natalizumab Treatment for Relapsing Multiple Sclerosis Stabilises Normal-Appearing White Matter Microstructure: A One-Year Prospective Ultra-High-Field Quantitative Imaging Study

(1) Background: Natalizumab dramatically reduces relapses and MRI inflammatory activity (new lesions and enhancing lesions) in multiple sclerosis (MS). Chemical exchange saturation transfer (CEST) MRI can explore brain tissue in vivo with high resolution and sensitivity. We investigated if natalizumab can prevent microstructural tissue damage progression measured with MRI at ultra-high field (7 Tesla) over the first year of treatment. (2) Methods: In this one-year prospective longitudinal study, patients with active relapsing-remitting MS were assessed clinically and scanned at ultra-high-field MRI at the time of their first natalizumab infusion, at 6 and 12 months, with quantitative imaging aimed to detect microstructural changes in the normal-appearing white matter (NAWM), including sequences sensitive to magnetisation transfer (MT) effects from amide proton transfer (MTRAPT) and the nuclear Overhauser effect (MTRNOE). (3) Results: 12 patients were recruited, and 10 patients completed the study. The difference in the T1 relaxation times at month 6 and month 12 of natalizumab treatment was not significant, suggesting the lack of accumulation of tissue damage, while improvements were seen in MTR (MTRAPT and MTRNOE measures) at month 12, suggesting a tissue repair effect. This paralleled the expected lack of clinical and radiological worsening of conventional MRI measures of disease activity (new lesions or gadolinium-enhancing lesions). (4) Conclusion: Natalizumab prevents microstructural brain damage and has effects suggesting an improved white matter microstructure measured at ultra-high field during the first year of treatment.

Meningeal inflammation as a driver of cortical grey matter pathology and clinical progression in multiple sclerosis

Growing evidence from cerebrospinal fluid samples and post-mortem brain tissue from individuals with multiple sclerosis (MS) and rodent models indicates that the meninges have a key role in the inflammatory and neurodegenerative mechanisms underlying progressive MS pathology. The subarachnoid space and associated perivascular spaces between the membranes of the meninges are the access points for entry of lymphocytes, monocytes and macrophages into the brain parenchyma, and the main route for diffusion of inflammatory and cytotoxic molecules from the cerebrospinal fluid into the brain tissue. In addition, the meningeal spaces act as an exit route for CNS-derived antigens, immune cells and metabolites. A number of studies have demonstrated an association between chronic meningeal inflammation and a more severe clinical course of MS, suggesting that the build-up of immune cell aggregates in the meninges represents a rational target for therapeutic intervention. Therefore, understanding the precise cell and molecular mechanisms, timing and anatomical features involved in the compartmentalization of inflammation within the meningeal spaces in MS is vital. Here, we present a detailed review and discussion of the cellular, molecular and radiological evidence for a role of meningeal inflammation in MS, alongside the clinical and therapeutic implications.

Updates and advances in multiple sclerosis neurotherapeutics

The multiple sclerosis (MS) neurotherapeutic landscape is rapidly evolving. New disease-modifying therapies (DMTs) with improved efficacy and safety, in addition to an expanding pipeline of agents with novel mechanisms, provide more options for patients with MS. While treatment of MS neuroinflammation is well tailored in the existing DMT armamentarium, concerted efforts are currently underway for identifying neuropathological targets and drug discovery for progressive MS. There is also ongoing research to develop agents for remyelination and neuroprotection. Further insights are needed to guide DMT initiation and sequencing as well as to determine the role of autologous stem cell transplantation in relapsing and progressive MS. This review provides a summary of these updates.

Quantitative magnetization transfer imaging in relapsing-remitting multiple sclerosis: a systematic review and meta-analysis

Myelin-sensitive MRI such as magnetization transfer imaging has been widely used in multiple sclerosis. The influence of methodology and differences in disease subtype on imaging findings is, however, not well established. Here, we systematically review magnetization transfer brain imaging findings in relapsing-remitting multiple sclerosis. We examine how methodological differences, disease effects and their interaction influence magnetization transfer imaging measures. Articles published before 06/01/2021 were retrieved from online databases (PubMed, EMBASE and Web of Science) with search terms including 'magnetization transfer' and 'brain' for systematic review, according to a pre-defined protocol. Only studies that used human in vivo quantitative magnetization transfer imaging in adults with relapsing-remitting multiple sclerosis (with or without healthy controls) were included. Additional data from relapsing-remitting multiple sclerosis subjects acquired in other studies comprising mixed disease subtypes were included in meta-analyses. Data including sample size, MRI acquisition protocol parameters, treatments and clinical findings were extracted and qualitatively synthesized. Where possible, effect sizes were calculated for meta-analyses to determine magnetization transfer (i) differences between patients and healthy controls; (ii) longitudinal change and (iii) relationships with clinical disability in relapsing-remitting multiple sclerosis. Eighty-six studies met inclusion criteria. MRI acquisition parameters varied widely, and were also underreported. The majority of studies examined the magnetization transfer ratio in white matter, but magnetization transfer metrics, brain regions examined and results were heterogeneous. The analysis demonstrated a risk of bias due to selective reporting and small sample sizes. The pooled random-effects meta-analysis across all brain compartments revealed magnetization transfer ratio was 1.17 per cent units (95% CI -1.42 to -0.91) lower in relapsing-remitting multiple sclerosis than healthy controls (z-value: -8.99, P < 0.001, 46 studies). Linear mixed-model analysis did not show a significant longitudinal change in magnetization transfer ratio across all brain regions [β = 0.12 (-0.56 to 0.80), t-value = 0.35, P = 0.724, 14 studies] or normal-appearing white matter alone [β = 0.037 (-0.14 to 0.22), t-value = 0.41, P = 0.68, eight studies]. There was a significant negative association between the magnetization transfer ratio and clinical disability, as assessed by the Expanded Disability Status Scale [r = -0.32 (95% CI -0.46 to -0.17); z-value = -4.33, P < 0.001, 13 studies]. Evidence suggests that magnetization transfer imaging metrics are sensitive to pathological brain changes in relapsing-remitting multiple sclerosis, although effect sizes were small in comparison to inter-study variability. Recommendations include: better harmonized magnetization transfer acquisition protocols with detailed methodological reporting standards; larger, well-phenotyped cohorts, including healthy controls; and, further exploration of techniques such as magnetization transfer saturation or inhomogeneous magnetization transfer ratio.

Economic burden of multiple sclerosis: a cross-sectional study in Iran

BACKGROUND

Multiple Sclerosis (MS) is a chronic debilitating disease that imposes a heavy socioeconomic burden on societies. This study aimed to determine the economic burden of MS on patients using the first (CinnoVex and ReciGen) and second (Fingolimod and Natalizumab) drug therapy lines.

METHODS

This cost of illness study was an economic evaluation carried out as cross-sectional research in 2019 in southern Iran. A total of 259 patients were enrolled in two lines of drug therapy (178 patients in the first line and 81 ones in the second). The prevalence-based approach and the bottom-up approach were used to collect cost information and to calculate the costs from the societal perspective, respectively. The human capital approach was applied to calculate indirect costs. To collect the required data a researcher-made data collection form was utilized. The data were obtained using the information available in the patients' medical records and insurance invoices as well as their self-reports or that of their companions.

RESULTS

The results showed that the annual costs of MS in the first and second lines of drug therapy per patient were $ 1919 and $ 4082 purchasing power parity (PPP), respectively, and in total, $ 2721 PPP in 2019. The highest mean costs in both lines were those of direct medical costs, of which purchasing the main medicines in both lines accounted for the highest.

CONCLUSION

Considering the findings of this study and in order to reduce the burden of the disease, the following suggestions are presented: providing necessary facilities for the production of MS drugs in the country; proper and equitable distribution of neurologists; expanding the provision of home care services; and using the technologies related to the Internet, including WhatsApp, to follow up the MS patients' treatment.

Myelin water imaging in relapsing multiple sclerosis treated with ocrelizumab and interferon beta-1a

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2-Year change in MS myelin water fraction favored ocrelizumab over interferon.

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Matched healthy controls showed no change in myelin water fraction over 2 years.

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Ocrelizumab appears to protect against demyelination in MS white matter and lesions.

Background

Myelin water imaging is a magnetic resonance imaging (MRI) technique that quantifies myelin damage and repair in multiple sclerosis (MS) via the myelin water fraction (MWF).

Objective

In this substudy of a phase 3 therapeutic trial, OPERA II, MWF was assessed in relapsing MS participants assigned to interferon beta-1a (IFNb-1a) or ocrelizumab (OCR) during a two-year double-blind period (DBP) followed by a two-year open label extension (OLE) with ocrelizumab treatment.

Methods

MWF in normal appearing white matter (NAWM), including both whole brain NAWM and 5 white matter structures, and chronic lesions, was assessed in 29 OCR and 26 IFNb-1a treated participants at weeks 0, 24, 48 and 96 (DBP), and weeks 144 and 192 (OLE), and in white matter for 23 healthy control participants at weeks 0, 48 and 96.

Results

Linear mixed-effects models of data from baseline to week 96 showed a difference in the change in MWF over time favouring ocrelizumab in all NAWM regions. At week 192, lesion MWF was lower for participants originally randomised to IFNb-1a compared to those originally randomised to OCR. Controls showed no change in MWF over 96 weeks in any region.

Conclusion

Ocrelizumab appears to protect against demyelination in MS NAWM and chronic lesions and may allow for a more permissive micro environment for remyelination to occur in focal and diffusely damaged tissue.

Effects of Fingolimod and Natalizumab on Brain T1-/T2-Weighted and Magnetization Transfer Ratios: a 2-Year Study

Fingolimod and natalizumab significantly reduce disease activity in relapsing-remitting multiple sclerosis (RRMS) and could promote tissue repair and neuroprotection. The ratio between conventional T1- and T2-weighted sequences (T1w/T2w-ratio) and magnetization transfer ratio (MTR) allow to quantify brain microstructural tissue abnormalities. Here, we compared fingolimod and natalizumab effects on brain T1w/T2w-ratio and MTR in RRMS over 2 years of treatment. RRMS patients starting fingolimod (n = 25) or natalizumab (n = 30) underwent 3T brain MRI scans at baseline (T0), month 6 (M6), month 12 (M12), and month 24 (M24). White matter (WM) lesions, normal-appearing (NA) WM, and gray matter (GM) T1w/T2w-ratio and MTR were estimated and compared between groups using linear mixed models. No baseline demographic, clinical, and MRI difference was found between groups. In natalizumab patients, lesion T1w/T2w-ratio and MTR significantly increased at M6 vs. T0 (p ≤ 0.035) and decreased at subsequent timepoints (p ≤ 0.037). In fingolimod patients, lesion T1w/T2w-ratio increased at M12 vs. T0 (p = 0.010), while MTR gradually increased at subsequent timepoints vs. T0 (p ≤ 0.027). Natalizumab stabilized NAWM and GM T1w/T2w-ratio and MTR. In fingolimod patients, NAWM T1w/T2w-ratio and MTR significantly increased at M24 vs. M12 (p ≤ 0.001). A significant GM T1w/T2w-ratio decrease at M6 vs. T0 (p = 0.014) and increase at M24 vs. M6 (p = 0.008) occurred, whereas GM MTR was significantly higher at M24 vs. previous timepoints (p ≤ 0.017) with significant between-group differences (p ≤ 0.034). Natalizumab may promote an early recovery of lesional damage and prevent microstructural damage accumulation in NAWM and GM during the first 2 years of treatment. Fingolimod enhances tissue damage recovery being visible after 6 months in lesions and after 2 years in NAWM and GM.

Promoting remyelination in multiple sclerosis

The greatest unmet need in multiple sclerosis (MS) are treatments that delay, prevent or reverse progression. One of the most tractable strategies to achieve this is to therapeutically enhance endogenous remyelination; doing so restores nerve conduction and prevents neurodegeneration. The biology of remyelination-centred on the activation, migration, proliferation and differentiation of oligodendrocyte progenitors-has been increasingly clearly defined and druggable targets have now been identified in preclinical work leading to early phase clinical trials. With some phase 2 studies reporting efficacy, the prospect of licensed remyelinating treatments in MS looks increasingly likely. However, there remain many unanswered questions and recent research has revealed a further dimension of complexity to this process that has refined our view of the barriers to remyelination in humans. In this review, we describe the process of remyelination, why this fails in MS, and the latest research that has given new insights into this process. We also discuss the translation of this research into clinical trials, highlighting the treatments that have been tested to date, and the different methods of detecting remyelination in people.

Occurrence and microstructural features of slowly expanding lesions on fingolimod or natalizumab treatment in multiple sclerosis

Background:

In multiple sclerosis (MS), up to 57% of white matter lesions are chronically active. These slowly expanding lesions (SELs) contribute to disability progression.

Objective:

The aim of this study is to compare fingolimod and natalizumab effects on progressive linearly enlarging lesions (i.e. SELs), a putative biomarker of smouldering inflammation.

Methods:

Relapsing-remitting MS patients starting fingolimod ( n = 24) or natalizumab ( n = 28) underwent 3T brain magnetic resonance imaging (MRI) at baseline, months 6, 12 and 24. SELs were identified among baseline-visible lesions showing ⩾ 12.5% of annual increase, calculated by linearly fitting the Jacobian of the nonlinear deformation field between timepoints obtained combining T1- and T2-weighted scans. SEL burden, magnetization transfer ratio (MTR) and T1 signal intensity were compared using linear models.

Results:

The prevalences of fingolimod (75%) and natalizumab patients (46%) with ⩾ 1 SEL were not significantly different (adjusted- p = 0.08). Fingolimod group had higher SEL number and volume (adjusted- p ⩽ 0.047, not false discovery rate (FDR) survived). In both groups, SELs versus non-SELs showed lower MTR and T1 signal intensity (adjusted- p ⩽ 0.01, FDR-survived). Longitudinally, non-SEL MTR increased in both treatment groups (adjusted- p ⩽ 0.005, FDR-survived). T1 signal intensity decreased in SELs with both treatments (adjusted- p ⩽ 0.049, FDR-survived in fingolimod group) and increased in natalizumab non-SELs (adjusted- p = 0.03, FDR-survived).

Conclusion:

The effects of natalizumab and fingolimod on SEL occurrence seem modest, with natalizumab being slightly more effective. Both treatments may promote reparative mechanisms in stable or chronic inactive lesions.

Magnetization transfer ratio: a quantitative imaging biomarker for 5q spinal muscular atrophy

BACKGROUND AND PURPOSE

We quantified peripheral nerve lesions in adults with 5q-linked spinal muscular atrophy (SMA) type 3 by analysing the magnetization transfer ratio (MTR) of the sciatic nerve, and tested its potential as a novel biomarker for macromolecular changes.

METHODS

Eighteen adults with SMA 3 (50% SMA 3a, 50% SMA 3b) and 18 age-/sex-matched healthy controls prospectively underwent magnetization transfer contrast imaging in a 3-Tesla magnetic resonance scanner. Two axial three-dimensional gradient echo sequences, with and without an off-resonance saturation rapid frequency pulse, were performed at the right distal thigh. Sciatic nerve regions of interest were manually traced on 10 consecutive axial slices in the images generated without off-resonance saturation, and then transferred to corresponding slices generated by the sequence with the off-resonance saturation pulse. Subsequently, MTR and cross-sectional areas (CSAs) of the sciatic nerve were analysed. In addition, detailed neurologic, physiotherapeutic and electrophysiologic examinations were conducted in all patients.

RESULTS

Sciatic nerve MTR and CSA reliably differentiated between healthy controls and SMA 3, 3a or 3b. MTR was lower in the SMA 3 (P < 0.0001), SMA 3a (P < 0.0001) and SMA 3b groups (P = 0.0020) than in respective controls. In patients with SMA 3, MTR correlated with all clinical scores, and arm nerve compound motor action potentials (CMAPs). CSA was lower in the SMA 3 (P < 0.0001), SMA 3a (P < 0.0001) and SMA 3b groups (P = 0.0006) than in controls, but did not correlate with clinical scores or electrophysiologic results.

CONCLUSIONS

Magnetization transfer ratio is a novel imaging marker that quantifies macromolecular nerve changes in SMA 3, and positively correlates with clinical scores and CMAPs.

Magnetization transfer ratio quantifies polyneuropathy in hereditary transthyretin amyloidosis

Objective

To quantify peripheral nerve lesions in symptomatic and asymptomatic hereditary transthyretin amyloidosis with polyneuropathy (ATTRv‐PNP) by analyzing the magnetization transfer ratio (MTR) of the sciatic nerve, and to test its potential as a novel biomarker for macromolecular changes.

Methods

Twenty‐five patients with symptomatic ATTRv‐PNP, 30 asymptomatic carriers of the mutant transthyretin gene (mutTTR), and 20 age‐/sex‐matched healthy controls prospectively underwent magnetization transfer contrast imaging at 3 Tesla. Two axial three‐dimensional gradient echo sequences with and without an off‐resonance saturation rapid frequency pulse were conducted at the right distal thigh. Sciatic nerve regions of interest were manually drawn on 10 consecutive axial slices in the images without off‐resonance saturation, and then transferred to the corresponding slices that were generated by the sequence with the off‐resonance saturation pulse. Subsequently, the MTR and cross‐sectional area (CSA) of the sciatic nerve were evaluated. Detailed neurologic and electrophysiologic examinations were conducted in all ATTRv‐PNP patients and mutTTR‐carriers.

Results

Sciatic nerve MTR and CSA reliably differentiated between ATTRv‐PNP, mutTTR‐carriers, and controls. MTR was lower in ATTRv‐PNP (26.4 ± 0.7; P < 0.0001) and in mutTTR‐carriers (32.6 ± 0.8; P = 0.0005) versus controls (39.4 ± 2.1), and was also lower in ATTRv‐PNP versus mutTTR‐carriers (P = 0.0009). MTR correlated negatively with the NIS‐LL and positively with CMAPs and SNAPs. CSA was higher in ATTRv‐PNP (34.3 ± 1.7 mm³) versus mutTTR‐carriers (26.0 ± 1.1 mm³; P = 0.0005) and versus controls (20.4 ± 1.2 mm³; P < 0.0001). CSA was also higher in mutTTR‐carriers versus controls.

Interpretation

MTR is a novel imaging marker that can quantify macromolecular changes in ATTRv‐PNP and differentiate between symptomatic ATTRv‐PNP and asymptomatic mutTTR‐carriers and correlates with electrophysiology.

Application of advanced MRI techniques to monitor pharmacologic and rehabilitative treatment in multiple sclerosis: current status and future perspectives

Introduction: Advances in magnetic resonance imaging (MRI) technology and analyses are improving our understanding of the pathophysiology of multiple sclerosis (MS). Due to their ability to grade the presence of irreversible tissue loss, microstructural tissue abnormalities, metabolic changes and functional plasticity, the application of these techniques is also expanding our knowledge on the efficacy and mechanisms of action of different pharmacological and rehabilitative treatments. Areas covered: This review discusses recent findings derived from the application of advanced MRI techniques to evaluate the structural and functional substrates underlying the effects of pharmacologic and rehabilitative treatments in patients with MS. Current applications as outcome in clinical trials and observational studies, their interpretation and possible pitfalls in their use are discussed. Finally, how these techniques could evolve in the future to improve monitoring of disease progression and treatment response is examined. Expert commentary: The number of treatments currently available for MS is increasing. The application of advanced MRI techniques is providing reliable and specific measures to better understand the targets of different treatments, including neuroprotection, tissue repair, and brain plasticity. This is a fundamental progress to move toward personalized medicine and individual treatment selection.

MD1003 (High-Dose Pharmaceutical-Grade Biotin) for the Treatment of Chronic Visual Loss Related to Optic Neuritis in Multiple Sclerosis: A Randomized, Double-Blind, Placebo-Controlled Study

BACKGROUND

Chronic visual loss is a disabling feature in patients with multiple sclerosis (MS). It was recently shown that MD1003 (high-dose pharmaceutical-grade biotin or hdPB) may improve disability in patients with progressive MS.

OBJECTIVE

The aim of this study was to evaluate whether MD1003 improves vision compared with placebo in MS patients with chronic visual loss.

METHODS

The MS-ON was a 6-month, randomized, double-blind, placebo-controlled study with a 6-month open-label extension phase. Adult patients with MS-related chronic visual loss of at least one eye [visual acuity (VA) below 0.5 decimal chart] were randomized 2:1 to oral MD1003 300 mg/day or placebo. The selected eye had to show worsening of VA within the past 3 years following either acute optic neuritis (AON) or slowly progressive optic neuropathy (PON). The primary endpoint was the mean change from baseline to month 6 in VA measured in logarithm of the minimum angle of resolution (logMAR) at 100% contrast of the selected eye. Visually evoked potentials, visual field, retinal nerve fiber layer (RNFL) thickness, and health outcomes were also assessed.

RESULTS

Ninety-three patients received MD1003 (n = 65) or placebo (n = 28). The study did not meet its primary endpoint, as the mean change in the primary endpoint was nonsignificantly larger (p = 0.66) with MD1003 (- 0.061 logMAR, + 3.1 letters) than with placebo (- 0.036 logMAR, + 1.8 letters). Pre-planned subgroup analyses showed that 100% contrast VA improved by a mean of + 2.8 letters (- 0.058 logMAR) with MD1003 and worsened by - 1.5 letters (+ 0.029 logMAR) with placebo (p = 0.45) in the subgroup of patients with PON. MD1003-treated patients also had nonsignificant improvement in logMAR at 5% contrast and in RNFL thickness and health outcome scores when compared with placebo-treated patients. There was no superiority of MD1003 vs placebo in patients with AON. The safety profile of MD1003 was similar to that of placebo.

CONCLUSIONS

MD1003 did not significantly improve VA compared with placebo in patients with MS experiencing chronic visual loss. An interesting trend favoring MD1003 was observed in the subgroup of patients with PON. Treatment was overall well tolerated.

TRIAL REGISTRATION

EudraCT identifier 2013-002112-27. ClinicalTrials.gov Identifier: NCT02220244 FUNDING: MedDay Pharmaceuticals.

Magnetic Resonance Imaging in Multiple Sclerosis

Since its technical development in the early 1980s, magnetic resonance imaging (MRI) has quickly been adopted as an essential tool in supporting the diagnosis, longitudinal monitoring, evaluation of therapeutic response, and scientific investigations in multiple sclerosis (MS). The clinical usage of MRI has increased in parallel with technical innovations in the technique itself; the widespread adoption of clinically routine MRI at 1.5T has allowed sensitive qualitative and quantitative assessments of macroscopic central nervous system (CNS) inflammatory demyelinating lesions and tissue atrophy. However, conventional MRI lesion measures lack specificity for the underlying MS pathology and only weakly correlate with clinical status. Higher field strength units and newer, advanced MRI techniques offer increased sensitivity and specificity in the detection of disease activity and disease severity. This review summarizes the current status and future prospects regarding the role of MRI in the characterization of MS-related brain and spinal cord involvement.

Long-Term Magnetization Transfer Ratio Evolution in Multiple Sclerosis White Matter Lesions

BACKGROUND AND PURPOSE

Magnetization transfer ratio (MTR), a magnetic resonance imaging technique used to assess tissue integrity, correlates with demyelination and axonal loss in multiple sclerosis (MS) lesions. In acute white matter lesions, short-term MTR changes mainly reflect demyelination and remyelination, in addition to edema and axonal and glial changes. Long-term MTR changes in MS lesions have not been studied extensively.

METHODS

A new quantitative image analysis method was developed to measure long-term MTR changes in MS lesions. The method was applied to a group of 59 patients and 14 healthy control subjects followed for 4 years. MTR changes in white matter lesions were analyzed, where lesion voxels were classified into six categories based on starting MTR and change over time. For each patient, the proportion of lesion voxels in each MTR-change category was calculated. Correlations between long-term MTR evolution, disability progression, and brain atrophy were investigated.

RESULTS

The proportion of lesion voxels in the high stable category correlated with less atrophy progression, while the proportion with low and increasing MTR correlated with increased atrophy. The proportion of lesion voxels in the high and stable MTR lesion category was significantly different between MS disease subgroups. The group with disability progression had a higher proportion of lesion voxels with low and increasing MTR.

CONCLUSIONS

These results suggest that long-term changes in MTR in white matter lesions can be used to distinguish lesion subtypes associated with MS disease progression and improve understanding of the temporal evolution of MS pathology.

The Role of Advanced Magnetic Resonance Imaging Techniques in Multiple Sclerosis Clinical Trials

Magnetic resonance imaging has been crucial in the development of anti-inflammatory disease-modifying treatments. The current landscape of multiple sclerosis clinical trials is currently expanding to include testing not only of anti-inflammatory agents, but also neuroprotective, remyelinating, neuromodulating, and restorative therapies. This is especially true of therapies targeting progressive forms of the disease where neurodegeneration is a prominent feature. Imaging techniques of the brain and spinal cord have rapidly evolved in the last decade to permit in vivo characterization of tissue microstructural changes, connectivity, metabolic changes, neuronal loss, glial activity, and demyelination. Advanced magnetic resonance imaging techniques hold significant promise for accelerating the development of different treatment modalities targeting a variety of pathways in MS.

Adrenocorticotropic hormone versus methylprednisolone added to interferon β in patients with multiple sclerosis experiencing breakthrough disease: a randomized, rater-blinded trial

BACKGROUND

The objective of this study was to evaluate monthly intramuscular adrenocorticotropic hormone (ACTH) gel versus intravenous methylprednisolone (IVMP) add-on therapy to interferon β for breakthrough disease in patients with relapsing forms of multiple sclerosis.

METHODS

This was a prospective, open-label, examiner-blinded, 15-month pilot study evaluating patients with Expanded Disability Status Scale (EDSS) score 3.0-6.5 and at least one clinical relapse or new T2 or gadolinium-enhanced lesion in the previous year. Twenty-three patients were randomized to ACTH (n = 12) or IVMP (n = 11) and completed the study. The primary outcome measure was the cumulative number of relapses. Secondary outcomes included EDSS, Mental Health Inventory (MHI), plasma cytokines, MS Functional Composite (MSFC), Quality-of-Life (MS-QOL) score, bone mineral density (BMD), and new or worsened psychiatric symptoms per month. Brain magnetic resonance imaging was analyzed post hoc. This was a preliminary and small-scale study.

RESULTS

Relapse rates differed significantly [ACTH 0.08, 95% confidence interval (CI) 0.01-0.54 versus IVMP 0.80, 95% CI 0.36-1.75; rate ratio, IVMP versus ACTH: 9.56, 95% CI 1.23-74.6; p = 0.03]. ACTH improved (p = 0.03) MHI (slope 0.95 ± 0.38 points/month; p = 0.02 versus slope -0.38 ± 0.43 points/month; p = 0.39). On-study decreases (all p < 0.05) in eight cytokine levels occurred only in the ACTH group. However, on-study EDSS, MSFC, MS-QOL, BMD, and MRI lesion changes were not significant between groups. Psychiatric symptoms per patient were greater with IVMP than ACTH (0.55, 95% CI 0.12-2.6 versus 0; p < 0.0001). Other common adverse events were insomnia and urinary tract infections (IVMP, seven events each) and fatigue or flu symptoms (ACTH, five events each).

CONCLUSIONS

This study provided class II evidence that ACTH produced better examiner-assessed cumulative rates of relapses per patient than IVMP in the adjunctive treatment of breakthrough disease in multiple sclerosis.

Grey matter atrophy is associated with disability increase in natalizumab-treated patients

Background:

Brain volume loss (BVL) is a key outcome in multiple sclerosis (MS) trials. Natalizumab is highly effective on inflammation with moderate impact on atrophy.

Objective:

To explore BVL in patients receiving natalizumab with an emphasis on grey matter (GM).

Methods:

We performed a retrospective post hoc analysis of BVL in 38 patients receiving natalizumab for 3 years using longitudinal voxel-based morphometry (VBM) and FreeSurfer.

Results:

Significant BVL was observed during first year: brain parenchymal fraction (BPF): −1.12% ( p < 0.001); white matter fraction (WMF): −0.9% ( p = 0.001); grey matter fraction (GMF): −1.28% ( p = 0.002). GM loss was found using VBM in bilateral cerebellum, cingulum, left > right fronto-parietal cortex, right > left hippocampus and left caudate. FreeSurfer showed significant volume losses in subcortical GM, brainstem and cerebellum, and cortical thinning in the left insula. In the second year, only WMF decrease (−0.6%; p = 0.015) was observed with no VBM changes, although FreeSurfer detected significant volume loss in thalamus, hippocampus and cerebellum. Baseline gadolinium enhancement influenced WMF and BPF changes during the first year, but not GMF. Patients with confirmed Expanded Disability Status Scale (EDSS) worsening at 3 years had lower baseline GMF and left thalamus volume and greater BVL over follow-up.

Conclusion:

BVL develops mainly during the first year of natalizumab therapy. GM changes are independent of baseline inflammation and correlate with disability.

Drug-associated progressive multifocal leukoencephalopathy: a clinical, radiological, and cerebrospinal fluid analysis of 326 cases

The implementation of a variety of immunosuppressive therapies has made drug-associated progressive multifocal leukoencephalopathy (PML) an increasingly prevalent clinical entity. The purpose of this study was to investigate its diagnostic characteristics and to determine whether differences herein exist between the multiple sclerosis (MS), neoplasm, post-transplantation, and autoimmune disease subgroups. Reports of possible, probable, and definite PML according to the current diagnostic criteria were obtained by a systematic search of PubMed and the Dutch pharmacovigilance database. Demographic, epidemiologic, clinical, radiological, cerebrospinal fluid (CSF), and histopathological features were extracted from each report and differences were compared between the disease categories. In the 326 identified reports, PML onset occurred on average 29.5 months after drug introduction, varying from 14.2 to 37.8 months in the neoplasm and MS subgroups, respectively. The most common overall symptoms were motor weakness (48.6 %), cognitive deficits (43.2 %), dysarthria (26.3 %), and ataxia (24.1 %). The former two also constituted the most prevalent manifestations in each subgroup. Lesions were more often localized supratentorially (87.7 %) than infratentorially (27.4 %), especially in the frontal (64.1 %) and parietal lobes (46.6 %), and revealed enhancement in 27.6 % of cases, particularly in the MS (42.9 %) subgroup. Positive JC virus results in the first CSF sample were obtained in 63.5 %, while conversion after one or more negative outcomes occurred in 13.7 % of cases. 52.2 % of patients died, ranging from 12.0 to 83.3 % in the MS and neoplasm subgroups, respectively. In conclusion, despite the heterogeneous nature of the underlying diseases, motor weakness and cognitive changes were the two most common manifestations of drug-associated PML in all subgroups. The frontal and parietal lobes invariably constituted the predilection sites of drug-related PML lesions.

A longitudinal uncontrolled study of cerebral gray matter volume in patients receiving natalizumab for multiple sclerosis

OBJECTIVE

Brain atrophy in multiple sclerosis (MS) selectively affects gray matter (GM), which is highly relevant to disability and cognitive impairment. We assessed cerebral GM volume (GMV) during one year of natalizumab therapy.

DESIGN/METHODS

Patients with relapsing-remitting (n = 18) or progressive (n = 2) MS had MRI ∼1 year apart during natalizumab treatment. At baseline, patients were on natalizumab for (mean ± SD) 16.6 ± 10.9 months with age 38.5 ± 7.4 and disease duration 9.7 ± 4.3 years.

RESULTS

At baseline, GMV was 664.0 ± 56.4 ml, Expanded Disability Status Scale (EDSS) score was 2.3 ± 2.0, timed 25-foot walk (T25FW) was 6.1±3.4 s; two patients (10%) had gadolinium (Gd)-enhancing lesions. At follow-up, GMV was 663.9 ± 60.2 mL; EDSS was 2.6 ± 2.1 and T25FW was 5.9 ± 2.9 s. One patient had a mild clinical relapse during the observation period (0.052 annualized relapse rate for the entire cohort). No patients had Gd-enhancing lesions at follow-up. Linear mixed-effect models showed no significant change in annualized GMV [estimated mean change per year 0.338 mL, 95% confidence interval -9.66, 10.34, p = 0.94)], GM fraction (p = 0.92), whole brain parenchymal fraction (p = 0.64), T2 lesion load (p = 0.64), EDSS (p = 0.26) or T25FW (p = 0.79).

CONCLUSIONS

This pilot study shows no GM atrophy during one year of natalizumab MS therapy. We also did not detect any loss of whole brain volume or progression of cerebral T2 hyperintense lesion volume during the observation period. These MRI results paralleled the lack of clinical worsening.

Nonconventional MRI and microstructural cerebral changes in multiple sclerosis

MRI has become the most important paraclinical tool for diagnosing and monitoring patients with multiple sclerosis (MS). However, conventional MRI sequences are largely nonspecific in the pathology they reveal, and only provide a limited view of the complex morphological changes associated with MS. Nonconventional MRI techniques, such as magnetization transfer imaging (MTI), diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) promise to complement existing techniques by revealing more-specific information on microstructural tissue changes. Past years have witnessed dramatic advances in the acquisition and analysis of such imaging data, and numerous studies have used these tools to probe tissue alterations associated with MS. Other MRI-based techniques-such as myelin-water imaging, (23)Na imaging, magnetic resonance elastography and magnetic resonance perfusion imaging-might also shed new light on disease-associated changes. This Review summarizes the rapid technical progress in the use of MRI in patients with MS, with a focus on nonconventional structural MRI. We critically discuss the present utility of nonconventional MRI in MS, and provide an outlook on future applications, including clinical practice. This information should allow appropriate selection of advanced MRI techniques, and facilitate their use in future studies of this disease.

Hematopoietic mobilization: Potential biomarker of response to natalizumab in multiple sclerosis

OBJECTIVE

To ascertain the mobilization from the bone marrow and the functional relevance of the increased number of circulating hematopoietic stem and progenitor cells (HSPC) induced by the anti-α-4 integrin antibody natalizumab in patients with multiple sclerosis (MS).

METHODS

We evaluated CD45(low)CD34+ HSPC frequency by flow cytometry in blood from 45 natalizumab-treated patients (12 of whom were prospectively followed during the first year of treatment as part of a pilot cohort and 16 prospectively followed for validation), 10 untreated patients with MS, and 24 healthy donors. In the natalizumab-treated group, we also assessed sorted HSPC cell cycle status, T- and B-lymphocyte subpopulation frequencies (n = 29), and HSPC differentiation potential (n = 10).

RESULTS

Natalizumab-induced circulating HSPC were predominantly quiescent, suggesting recent mobilization from the bone marrow, and were capable of differentiating ex vivo. Circulating HSPC numbers were significantly increased during natalizumab, but heterogeneously, allowing the stratification of mobilizer and nonmobilizer subgroups. Nonmobilizer status was associated with persistence of disease activity during treatment. The frequency of B cells and CD103+CD8+ regulatory T cells persistently increased, more significantly in mobilizer patients, who also showed a specific naive/memory B-cell profile.

CONCLUSIONS

The data suggest that natalizumab-induced circulating HSPC increase is the result of true mobilization from the bone marrow and has clinical and immunologic relevance. HSPC mobilization, associated with clinical remission and increased proportion of circulating B and regulatory T cells, may contribute to the treatment's mode of action; thus, HSPC blood counts could represent an early biomarker of responsiveness to natalizumab.

Immunomodulatory characteristics of mesenchymal stem cells and their role in the treatment of multiple sclerosis

Multiple Sclerosis (MS) is a chronic inflammatory neurodegenerative disease of central nervous system (CNS). Although the main cause of MS is not clear, studies suggest that MS is an autoimmune disease which attacks myelin sheath of neurons. There are different therapeutic regimens for MS patients including interferon (IFN)-β, glatiramer acetate (GA), and natalizumab. However, such therapies are not quite effective and are associated with some side effects. So which, there is no complete therapeutic method for MS patients. Regarding the potent immunomodulatory effects of mesenchymal stem cells (MSCs) and their ameliorative effects in experimental autoimmune encephalopathy (EAE), it seems that MSCs may be a new therapeutic method in MS therapy. MSC transplantation is an approach to regulate the immune system in the region of CNS lesions. In this review, we have tried to discuss about the immunomodulatory properties of MSCs and their therapeutic mechanisms in MS patients.

Effect of treatment with interferon beta-1a on changes in voxel-wise magnetization transfer ratio in normal appearing brain tissue and lesions of patients with relapsing-remitting multiple sclerosis: a 24-week, controlled pilot study

Background

This pilot study investigated changes in remyelinating and demyelinating activity in normal appearing brain tissue (NABT) and lesions, by using voxel-wise magnetization transfer ratio (VW-MTR), in patients with relapsing–remitting multiple sclerosis (RRMS) receiving interferon beta-1a 44 mcg subcutaneously (IFN β-1a SC) three times weekly versus healthy controls (HCs) (NCT01085318).

Methods

Increasing (suggestive of remyelination) and decreasing (suggestive of demyelination) VW-MTR changes in NABT and in T2, T1 and gadolinium (Gd)-enhancing lesion volume were measured over 24 weeks in 23 patients treated with IFN β-1a SC and in 15 HCs (where applicable). VW-MTR changes were tested using the Wilcoxon signed–rank or Wilcoxon rank–sum test.

Results

A trend for greater volume of NABT with increasing VW-MTR at 24 weeks was observed for patients versus HCs (median [range] 1206 [0–15278]; 342 [0–951] mm³; p = 0.061). NABT volume with increasing VW-MTR at 12 weeks was significantly greater in patients than in HCs (852 [6–11577]; 360 [0–1755] mm³; p = 0.028). Similar findings were detected for lesion volumes. Two patients with notably high numbers of Gd-enhancing lesions at baseline had a markedly greater volume of tissue with increasing VW-MTR compared with other patients. Volume of NABT tissue with decreasing VW-MTR was significantly greater in patients versus HCs at 24 weeks (942 [0–6141]; 297 [0–852] mm³; p<0.001).

Conclusions

The significant change in NABT volume with increasing VW-MTR at 12 weeks suggests that active remyelination in patients with RRMS may occur during treatment with IFN β-1a SC. Findings from two patients with the highest number of Gd-enhancing lesions at baseline suggest that extensive remyelination in NABT may occur in patients with high disease activity. Tissue volume with decreasing VW-MTR was greater in patients than in HCs, despite treatment, validating the sensitivity of this technique for detecting MS disease activity.

Trial Registration

ClinicalTrials.gov NCT01085318.

Remyelination therapy for multiple sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system characterized by infiltration of immune cells and progressive damage to myelin and axons. All therapeutics used to treat MS have been developed to target an overactive immune response, with aims to reduce disease activity. Chronic demyelinated axons are further prone to irreversible damage and death, and it is imperative that new therapies address this critical issue. Remyelination, the generation of new myelin in the adult nervous system, is an endogenous repair mechanism that restores function of denuded axons and delays their deterioration. Although remyelination can be extensive in some patients, the majority of cases limit repair only to the acute phase of disease. A significant current drive in new MS therapeutics is to identify targets that can promote remyelination by boosting endogenous oligodendrocyte precursor cells to form new myelin. Also, a number of inhibitory pathways have been identified in chronic MS lesions that prevent oligodendrocyte precursor cells from being properly recruited to demyelinated lesions or interfere with their differentiation to myelin-forming oligodendrocytes. In this review, we introduce the phenomenon of remyelination from the view of experimental models and studies in MS patients, describe a potential role in remyelination for currently available MS mediations, and discuss many avenues that are being actively studied to promote remyelination. The next frontier in MS therapeutics will supplement immunomodulation with agents that directly foster myelin repair, with aims to delay disease progression and recover lost neurological functions.