MS Abstracts 05c-2g5

Background
Whereas recent data from imaging studies challenge the prevailing notion that Multiple Sclerosis (MS) is purely an inflammatory disease, pathologic studies suggest differences in the disease processes between individual patients with MS.

The ability to dissect the pathophysiologic disease heterogeneity, if it indeed exists, by methodologies that can be applied in vivo is important both for the development of new therapeutics and for the ability to identify the optimal therapy for an individual patient.

Objective
To design a stratification algorithm for patients with MS based on accepted MRI measurements reflective of inflammation and Axonal damage/tissue loss and to assess if such MS subgroups retain their intergroup differences long term.

Methods
Mathematical modeling was used to select three discriminatory MRI measures for clinical outcome based on the cross-sectional analysis of 71 patients with untreated MS and tested general applicability of the stratification scheme on the independent longitudinal cohort of 71 MS patients.

Results
By consecutive employment of MRI measures reflective of inflammation and tissue loss, the authors were able to separate MS patients into four clinically meaningful subgroups.

The analysis of the longitudinal confirmatory cohort demonstrated persistence of the intergroup differences in selected MRI measures for 8 years.

Conclusions
The inflammatory activity and destructiveness of the Multiple Sclerosis process are to some degree independent of each other, and the successive evaluation of both of these variables can strengthen prediction of clinical outcome in individual patients.

Multiple Sclerosis afflicts more than 1 million individuals worldwide and is widely considered to be an Autoimmune Disease. Traditionally, CD4⁺ T-Helper Cells have almost exclusively been held responsible for its ImmunoPathogenesis.

Partly because certain MHC Class II alleles clearly predispose for developing Multiple Sclerosis and also, because of their importance in inducing Experimental Autoimmune Encephalomyelitis (EAE), the animal model for Multiple Sclerosis.

However, several strategies that target CD4⁺ T-Cells beneficially in EAE have failed to ameliorate disease activity in Multiple Sclerosis, and some have even triggered exacerbations.

Recently, the potential importance of CD8⁺ T-Cells has begun to emerge. Physiologically, CD8⁺ T-Cells are essential for detecting and eliminating abnormal cells, whether infected or neoplastic.

In Multiple Sclerosis, genetic associations with MHC Class I alleles have now been established, and CD8⁺ as well as CD4⁺ T-Cells have been found to invade and clonally expand in inflammatory Central Nervous System plaques.

Recent animal models induced by CD8⁺ T-Cells show interesting similarities to Multiple Sclerosis, in particular, in lesion distribution (more inflammation in the Brain relative to the Spinal Cord), although not all of the features of the human disease are recapitulated.

Here we outline the arguments for a possible role for CD8⁺ T-Cells, a Lymphocyte subset that has long been underrated in Multiple Sclerosis and should now be considered in new therapeutic approaches.

Multiple Sclerosis (MS) is a chronic inflammatory DeMyelinating disease of the Central Nervous System. The pathological hallmarks of MS lesions in the Brain and Spinal Cord are Inflammation, DeMyelination, Axon Loss and Gliosis.

Recent studies revealed heterogeneity in the mechanisms leading to the formation of lesions, which include typical autoimmune patterns of DeMyelination involving T-Cells and Macrophages, as well as AntiBody/Complement as characteristic effector mechanisms.

Additionally, Oligodendrocyte dystrophy patterns of DeMyelination, with disturbances of Oligodendroglial Myelin Protein expression and Oligodendrocyte Apoptosis, were observed.

Treatment of MS has advanced dramatically in recent years, with the introduction of beta-Interferons, Glatiramer Acetate and Mitoxantrone. However, not all MS patients respond well to treatment with these drugs, and this may be a consequence of disease heterogeneity.

Although ImmunoModulatory therapy has been clinically proven to be effective in patients with Relapsing/Remitting MS, studies in Secondary/Progressive MS patients have only demonstrated a positive therapeutic effect with iInterferon beta-1b.

The pathology and pathogenesis of lesions suggest the need for a subtype-specific treatment, which may be possible when observations from pathology can be acted upon in the living MS patient.

In addition to Myelin and Oligodendrocytedamage, the loss of Axons represents another key element of MS lesions that lacks a therapeutic approach.

However, Axon-protective therapy is yet to be established and the mechanisms and effector molecules involved in Axonal degeneration are still to be defined.

Objective
To evaluate the efficacy and safety of combination therapy with pulse Cyclophosphamide given with methylprednisolone (MP) and Interferon-beta (IFN-ß)-Ia in Multiple Sclerosis (MS) patients with active disease during IFN-ß monotherapy.

Methods
This was a randomized, single-blind, parallel-group, multicenter trial in MS patients with a history of active disease during IFN-ß treatment.

Patients were randomized to either Cyclophosphamide 800 mg/m2 plus MethylPrednisolone 1 g IV (CY/MP) or MethylPrednisolone once a month for six months and then followed for an additional 18 months.

All patients received three days of MethylPrednisolone 1 g IV at screening and 30 mcg IFN-ß-Ia IM weekly for the entire 24 months.

The primary endpoint was change from baseline in the mean number of Gadolinium-enhancing (Gd+) lesions. Secondary clinical endpoints included time to treatment failure.

Results
Fifty-nine patients were randomized to treatment: 30 to CY/MP and 29 to MP Change from baseline in the number of Gd+ lesions was significantly different between treatment groups at three (P =0.01), six (P =0.04) and 12 months (P =0.02), with fewer lesions in the CY/MP group.

The cumulative rate of treatment failure was significantly lower in the CY/MP group compared with the MP group (rate ratio =0.30; 95% confidence interval, 0.12-0.75; P =0.011). CY/MP treatment was well tolerated.

Conclusion
Combination therapy with CY/MP and IFN-ß-Ia decreased the number of Gd+ lesions and slowed clinical activity in patients with previously active disease on IFN-ß alone.

The INCOMIN study (INdependent COMparison of INterferons) lends further support to the growing body of evidence that both dose and frequency of Interferon-beta (IFN-ß) administration are important in the treatment of Multiple Sclerosis (MS).

High-dose, high-frequency IFN-ß (IFN-ß-1b 250 microg eod sc and IFN-ß-1a 44 microg sc) treatment offers greater therapeutic benefit, in terms of clinical and Magnetic Resonance Imaging (MRI) outcome measures, compared with low-dose, once-weekly administration of IFN-ß.

The importance of maintaining the most effective treatment regimen has been shown in another study.

The data from this study suggested that patients who have 'stable' disease (i.e. no evidence of clinical or MRI disease activity) during long-term treatment with IFN-ß-1b 250 microg:
• Who are subsequently treated with low-dose, once-weekly IFN-ß-1a 30 microg
1. Are more likely to experience:
   • Relapses
   • Disease progression or
   • MRI activity
2. Compared with those remaining on IFN-ß-1b 250 microg.

These data clearly indicate that frequently administered therapy must be maintained to achieve the optimal therapeutic benefit for patients.

Those patients who had their IFN-ß-1b 250 microg therapy reduced to low-dose, once-weekly IFN-ß-1a and experienced a resumption of disease activity were returned to their previous regimen.

However, after 1 year of additional follow-up, many of these patients still had clinical or MRI signs of disease activity, highlighting further the risks associated with the reduction of IFN-ß dose and frequency of administration.

Taking into consideration the evidence supporting the greater efficacy of IFN-ß-1b 250 microg or IFN-ß-1a 44 microg in MS it is of considerable interest to examine whether it is useful to increase the dose of IFN-ß-1b in patients who do not respond satisfactorily to the approved standard dose.

This is the rationale for the recently completed OPTIMS (OPTimization of Interferon for MS) study, in which partially responding patients were randomized to IFN-ß-1b 250 or 375 microg every other day. An interim safety analysis of OPTIMS patients has not raised any safety or tolerability concerns.

In summary, there is consistent evidence to support the importance of maintaining frequently administered IFN-ß (IFN-ß-1b microg or IFN-ß-1a 44 microg) for the treatment of MS.

Use of Intravenous ImmunoGlobulins (IVIG) has been recommended for treatment of RRMS if first line therapy with Interferon-beta or Glatiramer Acetate is not tolerated, or if contraindications exist.

This consensus recommendation is based on the demonstration of efficacy and tolerability of IVIG in four randomized controlled trials (RCTs).

The impact of non-randomized observational trials on evidence-based recommendations for treatment is still under discussion.

In order to evaluate the transferability of study results derived from RCTs into a routine practice setting, we carried out a retrospective data analysis on patients with RRMS who had been treated with IVIG during the last five years.

Data sets from 308 out of 1122 screened patients were available for analysis.

Treatment with IVIG resulted in a 69% reduction of the mean annual relapse rate (ARR) (calculated over two years) from 1.74+/-1.15 before IVIG treatment to 0.53+/-0.61 after start of IVIG treatment.

Mean Expanded Disability Status Scale (EDSS) values remained stable throughout the observation period. The results of this observational study were similar to the results of previous RCTs with IVIG.

The use of Interferon-beta (IFN-ß) in the treatment of Multiple Sclerosis (MS) has not changed greatly since its introduction.

However, two new treatment paradigms have recently emerged: initiation of treatment as early in the course of the disease as possible and the use of higher doses with greater frequency to gain maximum therapeutic effect.

The rationale for early treatment comes from evidence showing that early and irreversible pathology exists in very early stages of Relapsing/Remitting MS (RRMS).

Often, before significant disability is apparent and continues during remission. In addition, irreversible axonal damage begins early in the course of MS.

Two relatively short-term studies indicate that it is possible to delay the onset of MS by early treatment with low-dose IFN-ß-1a.

The BENEFIT (Betaferon((R))/Betaseron((R)) in Newly Emerging MS For Initial Treatment) study is being undertaken to investigate whether early intervention with a high-dose and more frequent administration of IFN-ß-1b (250 microg [8 MIU] every other day [eod]) has the ability to affect long-term clinical and Magnetic Resonance Imaging (MRI) outcomes even more favorably.

In addition, together with its follow-up study, BENEFIT will address the open question of long-term effects of early treatment on disease progression.

Results from the pivotal IFN-ß-1b study, together with data from PRISMS (Prevention of Relapses and Disability by Interferon-ß-1a Subcutaneously in Multiple Sclerosis) showed the presence of a dose-response relationship for IFN-ß in the treatment of RRMS.

This finding was confirmed by the results of INCOMIN (Independent Comparison of Interferons) and EVIDENCE (Evidence of Interferon Dose-response: European North American Comparative Efficacy).

Direct comparative studies of high-dose (250 microg IFN-ß-1b, 44 microg IFN-ß-1a), high-frequency versus lower dose (30 microg IFN-ß-1a) and less frequent IFN-ß regimens.

Results from a pilot study in patients with RRMS have indicated that increasing the dose of IFN-ß-1b to 500 microg (16 MIU) had a more pronounced biological effect compared with the standard 250 microg dose.

The BEYOND (Betaferon((R))/Betaseron((R)) Efficacy Yielding Outcomes of a New Dose) study is being undertaken to investigate whether IFN-ß-1b 500 microg eod is superior to the standard 250 microg eod dose in treatment-naive patients with RRMS.

A third treatment arm will provide a comparison with Glatiramer Acetate 20mg subcutaneously once daily.

Multiple Sclerosis is a chronic Inflammatory and DeMyelinating disorder of the CNS with an unknown Etiology. Although Intrathecal ImmunoGlobulin G (IgG) synthesis is a key feature of the disease, little is still known about the B-Cell response in the CNS of Multiple Sclerosis patients.

We analyzed the phenotype and kinetics of different B-Cell subsets in patients with Multiple Sclerosis, infectious disease (IND) and Non-Inflammatory Neurological Disease (NIND).

B-Cells were detected in the CSF of Multiple Sclerosis and IND patients, but were largely absent in NIND patients.

In the CSF, the majority of B-Cells had a phenotype of Memory B-Cells and short-lived Plasma Blasts (PB); Plasma Cells were absent from the compartment.

The proportion of PB was highest in Multiple Sclerosis patients and patients with acute CNS infection.

While PB disappeared rapidly from the CSF after resolution of infection in IND patients, these cells were present at high numbers throughout the disease course in Multiple Sclerosis patients.

CSF PB numbers in Multiple Sclerosis patients strongly correlated with Intrathecal IgG synthesis and Inflammatory Parenchymal Disease activity as disclosed by MRI.

This study identifies short-lived Plasma Blasts as the main effector B-Cell population involved in ongoing active inflammation in Multiple Sclerosis patients.

Background And Purpose
In recent studies, measures of Whole Brain Atrophy were strongly correlated with NeuroPsychological testing, explaining more variance than measures of lesion burden in patients with Multiple Sclerosis.

The relationship between Regional Lobar Atrophy and Cognitive Impairment is yet to be examined. We endeavored to assess the clinical significance of Regional Lobar Atrophy in Multiple Sclerosis.

Methods
In a cross-sectional study, we evaluated 31 patients with Multiple Sclerosis with Brain MR imaging and NeuroPsychological testing. Impairment was determined by comparison with demographically matched healthy controls.

MR imaging generated measures of lesion burden (Fluid-Attenuated Inversion Recovery HyperIntense volume), general Atrophy (Brain Parenchymal Fraction), Central Atrophy (Lateral Ventricle Volume), and Lobar Atrophy (Regional Brain Parenchymal Fraction of Frontal, Temporal, Parietal, and Occipital Lobes in each Hemisphere).

NeuroPsychological testing emphasized measures of Processing Speed and Memory, because these are commonly affected in Multiple Sclerosis.

Results
Patients with Multiple Sclerosis showed significant Atrophy and impairment on all NeuroPsychological tests. Regional Atrophy accounted for the most variance in all regression models predicting Memory performance.

Left Temporal Atrophy was the primary predictor of Auditory/Verbal Memory (partial r's = 0.55-0.61), and both left and Right Temporal Atrophy predicted Visual/Spatial Memory performance (Partial r's = 0.51-0.67).

Models predicting learning consistency retained Frontal Lobe Atrophy measures (partial r's = 0.44-0.68). Central and General Atrophy measures were the primary predictors in modeling Processing Speed (Partial r's = 0.42-0.64).

Conclusion
Regional Atrophy accounts for more variance than lesion burden, Whole Brain Atrophy, or Lateral Ventricle Volume in predicting Multiple Sclerosis-associated Memory Dysfunction.

Objective
Leflunomide, a potent disease-modifying AntiRheumatic drug of the Isoxazole class, exhibits AntiInflammatory, AntiProliferative, and ImmunoSuppressive effects by largely unknown mechanisms, although alterations of Pyrimidine synthesis have been proposed.

Successful Immune responsiveness requires T-Cell activation by interaction with Antigen-Presenting Cells (APCs), and Integrin activation and formation of an Immunologic Synapse (IS).

In this study, we evaluated the impact of the active Leflunomide metabolite Teriflunomide on T-Cell Integrin activation, evolution of the IS, and Antigen-specific formation of stable T-Cell/APC conjugates.

Methods
Effects of pharmacologic concentrations of Teriflunomide on CD3/CD28- and Lymphocyte function-associated Antigen 1-induced signal transduction and activation of primary human T-Cells were investigated.

Furthermore, T-Cells were stimulated with SuperAntigen- and Antigen-pulsed APCs to study relocalization of molecules to the IS and T-Cell/APC conjugate formation.

Results
Teriflunomide inhibited T-Cell Receptor (TCR)/CD3-mediated Calcium mobilization, but other critical T-Cell signaling events, including activation of MAPK and NF-kappaB, remained unaltered.

In contrast, inhibition of TCR/CD3-triggered ß1,2 Integrin avidity and Integrin-mediated costimulation (outside-in signaling) by Teriflunomide revealed a striking interference with Integrin function that was independent of altered Pyrimidine synthesis.

Moreover, Teriflunomide abolished molecule relocalization to the IS and induction of T-Cell/APC conjugates.

Disease-Modifying Treatments (DMTs) for Multiple Sclerosis (MS) are now widely available, and their beneficial effects on relapse rates, Magnetic Resonance Imaging outcomes and, in some cases, relapse-related disability have been shown in numerous clinical studies.

However, as these treatments are only partially effective in halting the MS disease process, the search for improved treatment regimens and novel therapies must continue.

Strategies to improve our therapeutic armamentarium have to take into account the different phases or parts of the pathogenesis of the disease.

Available treatments address systemic Immune dysfunction, Blood-Brain Barrier permeability and the inflammatory process in the Central Nervous System.

Currently, patients who fail to respond adequately to first-line DMTs are often considered as candidates for intensive ImmunoSuppression with cytostatic agents or even autologous Stem Cell Transplantation. However, new approaches are being developed.

Combination therapies offer an alternative approach that may have considerable potential to improve therapeutic yield and, although likely to present considerable challenges in terms of trial design, this certainly seems to be a logical step forward in view of the complex pathology of MS.

Several new drugs are also being developed with the aim of providing more effective, convenient and/or specific modulation of the inflammatory component of the disease.

These treatments include humanised MonoClonal AntiBodies such as the Anti-VLA-4 AntiBody Natalizumab, Inhibitors of IntraCellular activation, signalling pathways and T-Cell proliferation, and oral ImmunoModulators such as Sirolimus, Teriflunomide or Statins.

There remains, however, an urgent need for treatments that protect against DeMyelination and Axonal Loss, or promote ReMyelination/regeneration.

Due to the chronicity of MS, the therapeutic window for Neuroprotective Agents is wider than that following stroke or acute Spinal Cord injury, and may therefore allow the use of some drugs that have proven disappointing in other situations.

Novel potential NeuroProtective agents such as alpha-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid Antagonists and Ion-Channel Blockers will be entering Phase II trials in MS in the near future, and it is hoped that these agents will mark the start of a new era for DMTs for MS.

Focal DeMyelinated plaques in White Matter, which are the hallmark of Multiple Sclerosis pathology, only partially explain the patient's clinical deficits. We thus analyzed global Brain pathology in Multiple Sclerosis, focusing on the Normal-Appearing White Matter (NAWM) and the Cortex.

Autopsy tissue from 52 Multiple Sclerosis patients (acute, Relapsing/Remitting, Primary and Secondary/Progressive Multiple Sclerosis) and from 30 controls was analyzed using quantitative morphological techniques.

New and active focal inflammatory DeMyelinating lesions in the White Matter were mainly present in patients with acute and Relapsing Multiple Sclerosis, while Diffuse injury of the NAWM and Cortical DeMyelination were characteristic hallmarks of Primary and Secondary/Progressive Multiple Sclerosis.

Cortical DeMyelination and injury of the NAWM, reflected by Diffuse Axonal injury with profound Microglia activation, occurred on the background of a global inflammatory response in the Whole Brain and Meninges.

There was only a marginal correlation between focal lesion load in the White Matter and Diffuse White Matter injury, or Cortical pathology, respectively.

Our data suggest that Multiple Sclerosis starts as a focal inflammatory disease of the CNS, which gives rise to circumscribed DeMyelinated plaques in the White Matter.

With chronicity, Diffuse inflammation accumulates throughout the Whole Brain, and is associated with slowly progressive Axonal Injury in the NAWM and Cortical DeMyelination.