Disease-modifying Treatments For Multiple Sclerosis Research Articles

Alternatives to current disease-modifying treatment in MS: what do we need and what can we expect in the future?

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.

What do we know about the mechanism of action of disease-modifying treatments in MS?

Multiple sclerosis (MS), a chronic inflammatory disorder of the central nervous system (CNS), 2 results in damage to axons and their surrounding myelin sheath. The exact cause of inflammation remains unclear, but an autoimmune response directed against CNS antigens is suspected. MS can affect the brain, optic nerve and spinal cord, thus causing many neurological symptoms. These can include limb numbness or weakness, sensory or motor changes, ataxia, blurry vision, painful eye movements, bladder and bowel dysfunction, decreased memory, fatigue and effective disorders. This article will include a concise overview of the pathogenesis of MS in order to set the stage for subsequent discussion of the mechanisms of action of disease-modifying treatments, and whether these should influence our treatment choices. Although the exact pathogenesis of MS is not fully understood, current knowledge has already led to the development of effective treatments, namely interferon (IFN) 3 and glatiramer acetate, both of which have been shown to reduce relapse rates, while IFN 3- 1 a also reduces confirmed disability progression. Further increases in our understanding of the pathogenesis of MS are likely to assist in the identification of new targets for disease-modifying therapies and in the optimisation of current treatments..

The use of magnetic resonance imaging in multiple sclerosis: lessons learned from clinical trials.

Magnetic resonance imaging (MRI) is an important paraclinical tool for the diagnosis of multiple sclerosis (MS) and for monitoring its disease course. The efficacy of most of the available MS disease-modifying treatments has been tested in clinical trials where MRI-derived quantities served as primary or secondary outcome measures. However, conventional MRI measures (i.e., the number and volume of contrast-enhancing, the volumes of T2-hyperintense and T1-hypointense lesions and the assessment of brain volume changes) are limited in terms of pathological specificity and, as a consequence, are modestly correlated with clinical measures of disease activity and have a modest prognostic value as predictors of MS evolution. In the present review, we discuss the main factors potentially responsible for the so-called 'clinical MRI paradox' and how modern quantitative MR-based techniques might contribute to, at least partially, overcome it. The lessons learned from MS trials suggest that future applications of MRI to assess MS evolution should rely upon the use of composite measures thought to reflect the various components of the disease, as well as on study protocols specifically designed on the individual trial characteristics.

Non-specific immunosuppressants in the treatment of multiple sclerosis

Immunosuppressants have been proposed as disease-modifying treatments in multiple sclerosis (MS) for almost 40 years, but only one, mitoxantrone, has recently been approved, whereas β-interferons and glatiramer acetate have been licensed since the mid-90s. Recent therapeutic trials of potent immunosuppressive agents such as Campath-1H, mitoxantrone and cyclophosphamide of MS patients with high relapse rates, rapid accumulation of disability and high degree of MRI activity, have resulted in strong suppression of clinical and MRI inflammatory activity, provided that profound and prolonged lymphopenia was achieved. Clinical experience during the past decades has amply demonstrated that some patients with MS respond to immunosuppressants. The odds ratios of relapsing-remitting MS patients to remain relapse-free after a 2-year period of treatment are similar for Betaseron ®, Avonex ®, Rebif ®, Copaxone ®, intravenous immunoglobulins or azathioprine compared to placebo. The risk of cancer induction is not significant for up to 10 years of daily usage of azathioprine. Currently available non-specific immunosuppressants are able to control inflammation and reduce relapses in MS, but cannot prevent neurodegeneration and the progression of irreversible disability; specific tools need to be developed for that purpose.

Box and block test of manual dexterity in normal subjects and in patients with multiple sclerosis

Recently new disease-modifying treatments for multiple sclerosis (MS) were introduced which can change the natural course of the disease. In clinical trials with these new agents the Expanded Disability Status Scale (EDSS) is often used as a primary outcome instrument to measure neurological impairment and disability. A number of limitations have been identified when using the EDSS, some of wich are because the EDSS is an ordinal scale that is heavily biased to locomotor function. In this study we applied the box and block test of manual dexterity in normal subjects and relapsing-remitting MS patients. The results were that 64.8% of the female and 80.7% of the male patients had significant changes on this task compared with normal subjects, and as this test is easily applied and is sensitive in detecting upper extremity functional ability, we recommend its use in clinical trials to evaluate new drugs in MS patients.

Multiple sclerosis, disease modifying treatments and depression: a critical methodological review.

Major depression affects one in two patients with multiple sclerosis (MS) during the course of their lifetime. This adds to the morbidity associated with the disorder and may contribute to an increased mortality rate because of suicide. Over the past few years, with the advent of disease modifying treatments for MS, a new concern with respect to mood has arisen, namely the possibility that some of these drugs may have depression as a clinically significant side effect. To ascertain whether disease modifying treatments in MS are associated with the development of depression or the worsening of a depressive illness. A MEDLINE and PSYCHLIT search focusing on depression and disease modifying treatments going back to 1993 (the publication date of the results of the first randomised, placebo controlled trial). The methodology pertaining to the assessment of depression is critically reviewed. Furthermore, a critical summary is provided of treatment modalities for the depressed MS patient. There are conflicting data that depression may occur with some disease modifying drugs, particularly interferon beta-1b. However, all studies reveal limitations with respect to the assessment of mood. Some reports, despite omitting details of how mentation was assessed, still comment on the presence or absence of depression. Others suffer from one or more of the following shortcomings: a failure to assess premorbid risk factors for mood disorder; a reliance on one question to assess depression; the utilisation of self report mood rating scales of questionable validity; neglecting to distinguish depression as a symptom from depression as a syndrome (i.e. major depression as defined by the DMS-1V). Given the many methodological pitfalls inherent in all studies to date, it is premature to conclude that disease modifying drugs are associated with depression. Evidence suggests that treatment of depression, irrespective of a putative association with a disease modifying agent, is frequently effective. This applies to pharmacotherapy or psychotherapy, although the former may be preferred should depression arise during a course of treatment with a disease modifying agent. Multiple Sclerosis (2000) 6 343 - 348

How should we proceed with disease-modifying treatments for multiple sclerosis?

How should we proceed with disease-modifying treatments for multiple sclerosis?