Comparison of subcutaneous interferon beta-1a with glatiramer acetate in patients with relapsing multiple sclerosis (the REbif vs Glatiramer Acetate in Relapsing MS Disease [REGARD] study): a multicentre, randomised, parallel, open-label trial

Classical immunomodulatory therapy in multiple sclerosis: how it acts, how it works

Interferon beta (IFNβ) and glatiramer acetate (GA) were the first immunomodulators approved to the treatment of relapsing-remitting multiple sclerosis (MS) and clinically isolated syndromes. Despite the enlargement of the therapeutic armamentarium, IFNβ and GA remain the most widely drugs and the therapeutic mainstay of MS.

OBJECTIVE

To review the mechanisms of action of IFNβ and GA and main clinical results in MS.

RESULTS

IFNβ modulates T and B-cell activity and has effects on the blood-brain barrier. The well proved mechanism of GA is an immune deviation by inducing expression of anti-inflammatory cytokines. Some authors favor the neuroprotective role of both molecules. Clinical trials showed a 30% reduction on the annualized relapse rate and of T2 lesions on magnetic resonance.

CONCLUSION

Although the precise mechanisms how IFNβ and GA achieve their therapeutics effects remain unclear, these drugs have recognized beneficial effects and possess good safety and tolerability profiles. The large clinical experience in treating MS patients with these drugs along almost two decades deserves to be emphasized, at a time where the appearance of drugs with more selective mechanisms of action, but potentially less safer, pave the way to a better selection of the most appropriate individualized treatment.

Change in the clinical activity of multiple sclerosis after treatment switch for suboptimal response

BACKGROUND

  Therapy for multiple sclerosis (MS) has a partial efficacy, and a significant proportion of treated patients will develop a suboptimal response with first-line disease-modifying drugs (DMD). Therapy switch in patients with MS can be a strategy after a treatment failure. We studied the change in clinical activity after switching of first-line DMD because of a treatment failure.

METHODS

  Relapsing-remitting multiple sclerosis (RRMS) patients treated with interferon-beta (IFNB) or glatiramer acetate (GA) were divided into (i) patients without change in DMD, (ii) patients with a change in DMD because of a poor response, and (iii) those with a change in DMD without relation with response. Annualized relapse rate (ARR) and relapse-free proportions were analyzed.

RESULTS

  We identified 923 patients with RRMS. Of the 180 who experienced a change because of suboptimal response, 90 switched to another first-line DMT, 38 to mitoxantrone, and 52 to natalizumab. Median ARR in the pre-DMD period on first DMD and second DMD was the following: 1, 1, and 0 for switchers from IFNB to another IFNB (P = 0.0001); 0.67, 1, and 0 for switchers from GA to IFNB (P = 0.01); 1, 1, and 0 for switchers from an IFNB to GA (P = 0.02); 1.1, 1.5, 0.2 for switchers from IFNB or GA to mitoxantrone (P = 0.0001); 0.9, 1, 0 for switchers from IFNB or GA to natalizumab (P = 0.0001).

CONCLUSIONS

  In patients with RRMS who have a poor response, switch to another DMD may reduce the clinical activity of the disease.

Systematic review of disease-modifying therapies to assess unmet needs in multiple sclerosis: tolerability and adherence

Reviews of therapeutic drugs usually focus on the highly selected and closely monitored patient populations from randomized controlled trials. The objective of this study was to review systematically the tolerability and adherence of multiple sclerosis disease-modifying therapies, using data from both randomized controlled trials and observational settings. Relevant literature was identified using predefined search terms, and adverse event and study discontinuation data were extracted and categorized according to study type (randomized controlled trial or observational) and study duration. A total of 151 papers were selected for analysis; 33% were classified as randomized controlled trials and 62% as observational studies. Most of the papers concerned interferon preparations and glatiramer acetate; the limited available information on mitoxantrone and natalizumab precluded extensive examination of these. The most common adverse events were flu-like symptoms (interferon therapies only) and injection-site reactions. Mean discontinuation rates ranged from 16% to 27%. There were no marked differences in tolerability or adherence data from randomized controlled trials and observational studies, but the incidence of adverse events remained high in lengthy studies and discontinuations accumulated with time. The present systematic review of randomized clinical trial and observational data highlights the tolerability and adherence issues associated with commonly used first-line multiple sclerosis treatments.

New and emerging disease modifying therapies for multiple sclerosis

Several disease-modifying drugs (DMDs) are currently approved for the treatment of multiple sclerosis (MS). Recently, there has been increased identification and development of potential new treatments that may modulate the MS disease process, including oral therapies. Many of the newly approved MS therapies, as well as those in ongoing clinical trials, have the advantage of improved efficacy and/or being oral and more convenient, as compared to conventional injectable first-line MS therapies. However, many of these new and emerging MS treatments are known to be associated with serious adverse events, some of which may be potentially life threatening. Of additional concern, there is limited experience and long-term safety data for many of these drugs, and thus the true potential for complications associated with these agents remains ambiguous. With an anticipated explosion in the artillery of available MS therapies in the near future, neurologists will need to carefully weigh drug efficacy, convenience, safety, and tolerability when making therapeutic decisions. In this review, we describe the known mechanisms of action, efficacy, and side-effect profiles of new and emerging MS DMDs.

Current and emerging therapies for the treatment of multiple sclerosis: focus on cladribine

Multiple Sclerosis (MS) is a chronic inflammatory, immune-mediated, demyelinating disorder of the central nervous system with a heterogeneous clinical presentation and pathology in which activated lymphocytes play an important role in mediating tissue damage. Until recently, all first line therapies for MS were injectable. Several oral medications have been studied for preventative treatment of MS. Cladribine (2-chlorodeoxyadenosine) is a purine nucleoside analog that has been used for the treatment of several hematologic neoplasms, with a unique lymphcytotoxic mechanism of action. Cladribine has been investigated as treatment of MS for more than 15 years. A recent placebo-controlled, double-blind study of cladribine, CLARITY, showed decreased relapse rates, risk of disability progression and MRI measures of disease activity at 96 weeks. Cladribine's strengths included high efficacy and convenient, biannual oral dosing. However, concerns about safety prevented the FDA from approving cladribine in 2011. Thus, use of cladribine for treatment of relapsing and remitting multiple sclerosis will remain off-label.

Clinical predictors of response to immunomodulators for multiple sclerosis

OBJECTIVES: To determine, based on clinical criteria, the proportion of multiple sclerosis (MS) patients responsive to immunomodulators (RI) and nonresponsive to immunomodulators (NRI), and to ascertain whether clinical and epidemiological data differs between RI and NRI patient groups. METHODS: Patients were assessed on rate of exarcerbations per year, for the period before and after commencement of treatment. The RI and NRI groups were compared for several clinical and epidemiological characteristics. DISCUSSION AND CONCLUSION: A total of 31.4% of the patients were nonresponders to the immunomodulatory treatment. The main predictors of immunomodulatory response were early diagnostic and commencement of therapy and high rate of annual exacerbations prior to treatment. Given the arsenal of medication options available for MS management, screening potential candidates for different therapeutic approaches are critical to optimize evolution of patients with the disease.

Cost-effectiveness analysis of disease modifiying drugs (interferons and glatiramer acetate) as first line treatments in remitting-relapsing multiple sclerosis patients

Abstract Objective: The aim of this study was to assess cost-effectiveness of the different Disease Modifying Drugs (DMD) used as first-line treatments (interferons IM IFNβ-1a, SC IFNβ-1a, SC IFNβ-1b, and glatiramer acetate, GA) in Remitting-Relapsing Multiple Sclerosis (RRMS) in Spain.

METHODS

A Markov model was developed to simulate the progression of a cohort of patients with RRMS, during a period of 10 years. Seven health states, defined by the Expanded Disability Status Scale (EDSS), were considered in the model. Patients with an EDSS score less than 6.0 were assumed to be treated with one of the DMD. In addition, all patients were assumed to receive symptomatic treatment. The monthly transition probabilities of the model were obtained from the literature. The analysis was performed from the societal perspective, in which both direct and indirect (losses in productivity) healthcare costs (€, 2010) were included. A discount rate of 3% was applied to both costs and efficacy results.

RESULTS

GA was the less costly strategy (€322,510), followed by IM IFNβ-1a (€329,595), SC IFNβ-1b (€ 333,925), and SC IFNβ-1a (€348,208). IM IFNβ-1a has shown the best efficacy results, with 4.176 quality-adjusted life years (QALY), followed by SC IFNβ-1a (4.158 QALY), SC IFNβ-1b (4.157 QALY), and GA (4.117 QALY). Incremental costs per QALY gained with IM IFNβ-1a were €-1,005,194/QALY, €-223,397/QALY, and €117,914/QALY in comparison to SC IFNβ-1a, SC IFNβ-1b, and GA, respectively.

CONCLUSIONS

First-line treatment with GA is the less costly strategy for the treatment of patients with RRMS. Treatment with IM IFNβ-1a is a dominant strategy (lower cost and higher QALY) compared with SC IFNβ-1a and SC IFNβ-1b. However, IM IFNβ-1a is not a cost-effective strategy vs GA, because incremental cost per QALY gained with IM IFNβ-1a exceeds the €30,000 per QALY threshold commonly used in Spain.

LIMITATIONS

The highly-restrictive inclusion criteria of clinical trials limits generalization of the results on efficacy to all patients with multiple sclerosis. Availability of data for head-to-head comparisons is associated with the use of information from clinical trials.

Can a physician predict the clinical response to first-line immunomodulatory treatment in relapsing-remitting multiple sclerosis?

BACKGROUND

Decreased relapse rate and slower disease progression have been reported with long-term use of immunomodulatory treatments (IMTs, interferon beta or glatiramer acetate) in relapsing-remitting multiple sclerosis. There are, however, patients who do not respond to such treatments, and they can be potential candidates for alternative therapeutic approaches.

OBJECTIVE

To identify clinical factors as possible predictors of poor long-term response.

METHODS

A 9-year prospective, continuous follow-up at a single center in Hungary to assess clinical efficacy of IMT.

RESULTS

In a patient group of 81 subjects with mean IMT duration of 54 ± 33 months, treatment efficacy expressed as annual relapse rate and change in clinical severity from baseline did not depend on the specific IMT (any of the interferon betas or glatiramer acetate), and on mono- or multifocal features of the initial appearance of the disease. Responders had shorter disease duration and milder clinical signs at the initiation of treatment. Relapse-rate reduction in the initial 2 years of treatment predicted clinical efficacy in subsequent years.

CONCLUSION

Based on these observations, we suggest that a 2-year trial period is sufficient to decide on the efficacy of a specific IMT. For those with insufficient relapse reduction in the first 2 years of treatment, a different IMT or other therapeutic approaches should be recommended.

Placebo-controlled trials in relapsing–remitting multiple sclerosis: are they still needed?

Placebo-controlled clinical trials are an important tool to verify the efficacy of therapeutic approaches. During recent years, many trials have been conducted into relapsing–remitting multiple sclerosis, resulting in a variety of treatment options considered effective based on prospective, randomized controlled trials with masked outcome assessment in a representative population of patients (class I evidence). Accordingly, treatment is recommended because the benefit of treatment outweighs the potential risks (level A recommendation), whereas no treatment or delay of treatment may potentially harm patients. Placebo-controlled trials seem to be outdated in relapsing–remitting multiple sclerosis because they: cannot predict where a new treatment is placed in relation to the already established therapies, lead to the recruitment of inactive and nonrepresentative patient populations, delay the registration process due to slow recruitment, change the genetic background of study populations due to a shift of clinical trials to Asian countries and are unethical.

Subcutaneous recombinant interferon-β-1a (Rebif®): a review of its use in the treatment of relapsing multiple sclerosis

Subcutaneous recombinant interferon-β-1a (SC IFNβ-1a) [Rebif®] is indicated as monotherapy for the prevention of relapses and progression of physical disability in patients with relapsing multiple sclerosis (MS). This article reviews the efficacy and tolerability of SC IFNβ-1a in this indication, with further discussion of its pharmacological properties and pertinent pharmacoeconomic studies. SC IFNβ-1a efficacy and tolerability were evaluated in randomized, double-blind, multinational trials in patients with relapsing-remitting MS (RRMS). Its efficacy was demonstrated in the 2-year PRISMS trial, as SC IFNβ-1a 22 or 44 μg three times weekly (tiw) significantly reduced relapse rates, with an ≈30% relative risk reduction compared with placebo. SC IFNβ-1a was also associated with significantly delayed progression of disability, and lower disease activity according to MRI, relative to placebo. In the 24-week EVIDENCE trial, a significantly higher proportion of SC IFNβ-1a 44 μg tiw than intramuscular IFNβ-1a (Avonex®) 30 μg once weekly recipients remained relapse free. A serum-free formulation of SC IFNβ-1a 44 μg tiw was more efficacious than placebo in preventing the development of brain lesions in the 16-week IMPROVE trial. In the 96-week REGARD trial, the efficacy of SC IFNβ-1a 44 μg tiw was not significantly different to that of glatiramer acetate for clinical endpoints, although it was associated with reduced development of brain lesions compared with glatiramer acetate, according to some MRI endpoints. In the 36-month CAMMS223 trial, alemtuzumab led to significantly lower relapse rates and risk of developing sustained disability than SC IFNβ-1a 44 μg tiw, and was generally more efficacious according to other clinical and MRI endpoints. Across trials, influenza-like symptoms, injection-site reactions, haematological disturbances and hepatic enzyme abnormalities were the most common treatment-emergent adverse events occurring with SC IFNβ-1a. In the PRISMS trial, SC IFNβ-1a 22 and 44 μg tiw recipients had more injection-site reactions than placebo recipients and, at the higher dosage, haematological disturbances and increases in ALT levels were also significantly more frequent than with placebo. Pooled data from clinical trials and postmarketing surveillance indicate that haematological and hepatic adverse events are generally asymptomatic and rarely result in treatment discontinuation. Nevertheless, some cases of serious hepatic complications have been reported. In cost-utility studies, first-line therapies for RRMS, including SC IFNβ-1a, all exceeded commonly accepted US thresholds for incremental cost per quality-adjusted life-years gained relative to symptomatic treatment. However, because of patient need and the difficulty in adequately assessing cost utility in a gradually progressive disease, these agents have been made available to many patients worldwide through special access programmes. Overall, SC IFNβ-1a has a favourable risk-benefit ratio and is a valuable first-line treatment option for patients with relapsing MS.

Establishing long-term efficacy in chronic disease: use of recursive partitioning and propensity score adjustment to estimate outcome in MS

Context

Establishing the long-term benefit of therapy in chronic diseases has been challenging. Long-term studies require non-randomized designs and, thus, are often confounded by biases. For example, although disease-modifying therapy in MS has a convincing benefit on several short-term outcome-measures in randomized trials, its impact on long-term function remains uncertain.

Objective

Data from the 16-year Long-Term Follow-up study of interferon-beta-1b is used to assess the relationship between drug-exposure and long-term disability in MS patients.

Design/Setting

To mitigate the bias of outcome-dependent exposure variation in non-randomized long-term studies, drug-exposure was measured as the medication-possession-ratio, adjusted up or down according to multiple different weighting-schemes based on MS severity and MS duration at treatment initiation. A recursive-partitioning algorithm assessed whether exposure (using any weighing scheme) affected long-term outcome. The optimal cut-point that was used to define “high” or “low” exposure-groups was chosen by the algorithm. Subsequent to verification of an exposure-impact that included all predictor variables, the two groups were compared using a weighted propensity-stratified analysis in order to mitigate any treatment-selection bias that may have been present. Finally, multiple sensitivity-analyses were undertaken using different definitions of long-term outcome and different assumptions about the data.

Main Outcome Measure

Long-Term Disability.

Results

In these analyses, the same weighting-scheme was consistently selected by the recursive-partitioning algorithm. This scheme reduced (down-weighted) the effectiveness of drug exposure as either disease duration or disability at treatment-onset increased. Applying this scheme and using propensity-stratification to further mitigate bias, high-exposure had a consistently better clinical outcome compared to low-exposure (Cox proportional hazard ratio = 0.30–0.42; p<0.0001).

Conclusions

Early initiation and sustained use of interferon-beta-1b has a beneficial impact on long-term outcome in MS. Our analysis strategy provides a methodological framework for bias-mitigation in the analysis of non-randomized clinical data.

Trial Registration

Clinicaltrials.govNCT00206635

Efficacy, safety, and cost-effectiveness of glatiramer acetate in the treatment of relapsing-remitting multiple sclerosis

The current Multiple Sclerosis (MS) therapeutic landscape is rapidly growing. Glatiramer acetate (GA) remains unique given its non-immunosuppressive mechanism of action as well as its superior long-term safety and sustained efficacy data. In this review, we discuss proposed mechanisms of action of GA. Then we review efficacy data for reduction of relapses and slowing disability as well as long term safety data. Finally we discuss possible future directions of this unique polymer in the treatment of MS.

Glatiramer acetate antibodies, gene expression and disease activity in multiple sclerosis

BACKGROUND

Glatiramer acetate (GA) treatment suppresses disease activity in multiple sclerosis (MS). The immunological response to treatment may differ in patients who are stable on GA therapy and patients with breakthrough disease activity, but the results of previous studies are inconsistent.

OBJECTIVES

We studied the immunological response to GA and its relationship with disease activity.

METHODS

Anti-GA antibodies in plasma and the expression of genes encoding cytokines and T-cell-polarizing transcription factors in blood cells were analysed by flow cytometric bead array and polymerase chain reaction (PCR) analysis in 39 untreated and 29 GA-treated relapsing-remitting MS patients. Definition of breakthrough disease was based on the occurrence of relapses, disability progression, or gadolinium (Gd)-enhanced MRI.

RESULTS

The expression of T helper type 1 (Th1) and Th17 cytokines and transcription factors was reduced during long-term treatment, but there was no relationship between the expression of cytokines and transcription factors and anti-GA antibodies. High expression of mRNA encoding GATA3 and lymphotoxin-β (LT-β) was associated with low disease activity in Gd-enhanced MRI studies. None of the variables studied were associated with clinical disease activity. GA treatment resulted in the development of IgG and IgG4 anti-GA antibodies during the first months of treatment, persisting during long-term treatment.

CONCLUSIONS

The observed relationship between the expression of mRNA encoding GATA3 and LT-β expression and MRI disease activity deserves further analysis in future studies. The development of anti-GA antibodies was observed in all patients treated with GA, but this was not related with measures of cellular immunity, clinical or MRI disease activity.

Principles of a new treatment algorithm in multiple sclerosis

We are entering a new era in the management of patients with multiple sclerosis (MS). The first oral treatment (fingolimod) has now gained US FDA approval, addressing an unmet need for patients with MS who wish to avoid parenteral administration. A second agent (cladribine) is currently being considered for approval. With the arrival of these oral agents, a key question is where they may fit into the existing MS treatment algorithm. This article aims to help answer this question by analyzing the trial data for the new oral therapies, as well as for existing MS treatments, by applying practical clinical experience, and through consideration of our increased understanding of how to define treatment success in MS. This article also provides a speculative look at what the treatment algorithm may look like in 5 years, with the availability of new data, greater experience and, potentially, other novel agents.

Adherence and persistence among multiple sclerosis patients after one immunomodulatory therapy failure: retrospective claims analysis

INTRODUCTION

There are no published data on patient adherence to, and persistence with, disease-modifying therapies (DMT) for multiple sclerosis (MS) after one immunomodulatory failure. The present study compares secondline DMT adherence and persistence among patients with MS.

METHODS

Patients with MS initiating a second-line treatment with natalizumab, intramuscular interferon beta-1a (i.m.-IFNβ-1a), subcutaneous (s.c.) IFNβ-1a, interferon beta-1b (IFNβ-1b), and glatiramer acetate (GA) from January 1, 2006 to October 4, 2008 were identified from a retrospective claims database associated with a large US health plan. Adherence was measured with medication possession ratio (MPR); adherence indicated MPR ≥ 0.80. Persistence was measured as time until a minimum 60-day gap in second-line therapy. Adherence and persistence were modeled with logistic and Cox proportional hazard regressions, respectively.

RESULTS

The study population comprised 1381 patients. Multivariate analysis showed that the odds of adherence were significantly higher in the natalizumab cohort compared with all other second-line cohorts. The natalizumab cohort was more likely to be persistent compared with the i.m.-IFNβ-1a and IFNβ-1b cohorts.

CONCLUSION

The natalizumab cohort was more adherent compared with the other second-line DMT cohorts, likely due in large part to active physician involvement and monitoring. Adherence to DMT, even after first-line failure, is critical to achieving optimal therapeutic benefit.

Challenges to clinical trials in multiple sclerosis: outcome measures in the era of disease-modifying drugs

PURPOSE OF REVIEW

This review summarizes standard and evolving outcome measures in multiple sclerosis (MS) clinical trials.

RECENT FINDINGS

Progress in the development of MS treatments has led to an increasing number of clinical trials and a need for sensitive, timely, and clinically relevant outcome measures. Relapse rate and the Expanded Disability Status Scale remain the standard clinical outcome measures, but the MS Functional Composite continues to gain additional validation as a meaningful outcome measure. The uncertain relationship between MRI outcome measures and clinical disability has been a persistent challenge in MS clinical trials, but there is increasing evidence supporting a correlation between MRI changes and disability in relapsing-remitting MS patients. Additionally, new imaging techniques are being developed to further increase the sensitivity of MRI as a tool in MS clinical trials. Optical coherence tomography is another outcome measure gaining influence in clinical trials. Some of the greatest challenges remain in the subset of primary progressive MS clinical trials in which brain atrophy appears to be the most promising imaging outcome measure, but the optimal clinical measures and study durations are still uncertain.

SUMMARY

Progress in MS clinical trials requires critical evaluation of existing and future outcome measures and their relationships to one another.

Fatigue and cognition in patients with relapsing multiple sclerosis treated with interferon β

INTRODUCTION

Fatigue and cognitive deficits are common symptoms affecting patients with multiple sclerosis.

METHODS

The effects of interferon beta on fatigue and cognitive deficits were assessed in 50 patients with relapsing multiple sclerosis (recruited at a single center). The pre-treatment assessments were performed on visits 1 and 2 (Months 0 and 3). Patients started treatment with subcutaneous interferon beta-1a or beta-1b, or intramuscular interferon beta-1a at Month 3, with reassessment at visits 3 and 4 (6 and 12 months, respectively). Co-primary endpoints were change in fatigue (Modified Fatigue Impact Scale) and change in cognition (Brief Repeatable Battery of Neuropsychological Tests) from pre-treatment to visits 3 and 4. Follow-up data were obtained for 40 patients.

RESULTS

The pre-treatment demographic and disease characteristics did not differ between groups. Improvements in fatigue levels were reported for patients receiving subcutaneous interferon beta-1a versus patients in the intramuscular interferon beta-1a group (p = .04) and in the interferon beta-1b group (p = .09). Improvements were also reported in five out of 17 cognitive indices for all the treatment groups.

CONCLUSION

The data suggest that interferon beta may reduce fatigue and cognitive deficits in patients with relapsing multiple sclerosis. Larger, randomized, and controlled studies are required to confirm our findings.

The changing face of multiple sclerosis clinical trial populations

BACKGROUND

Since the commercial introduction of disease-modifying drugs (DMDs) for the treatment of multiple sclerosis (MS), there have been numerous randomized placebo-controlled and head-to-head clinical trials assessing the efficacy and safety of these agents in relapsing-remitting MS (RRMS).

SCOPE

Recent trials in the past 10 years demonstrate that the characteristics and behavior of clinical trial populations in RRMS have changed. Here we review evidence from key published clinical trials of DMDs in RRMS that highlights the general shift in trial populations, and examine the implications of this shift for future trial design.

FINDINGS

Populations in recent studies are characterized by lower clinical disease activity. This difference is apparent with regards to baseline patient characteristics and on-study behavior in terms of outcomes (e.g., relapse rates). The reasons for this shift are probably multifactorial and include study design, current treatment options, patient selection, and a possible change in the natural history of MS.

CONCLUSIONS

The variation among study designs makes it difficult to draw more extensive conclusions about changes in clinical trial populations. However, these recent changes undoubtedly will affect interpretation of recent study results, some of which based clinical and statistical assumptions on earlier trials. Furthermore, the shift in populations has major implications for the design of future studies: (1) assumptions regarding effect size and statistical powering must be based on comparable patient populations; (2) larger trials of longer duration may be needed, possibly with stopping criteria based on the number of actual events rather than a preset, fixed time point for the end of study; (3) the use of biomarkers to facilitate identification of subpopulations may be considered; and (4) enhanced measures of disease activity (e.g., composite outcomes) may help to identify effects in multiple relevant MS outcomes. Furthermore, trial design may need to be modified to study the effects of a medication in patients who are representative of the anticipated patient population. To ensure that the clinical trial experience of a drug is reflected in its eventual clinical use, 'real-life' observation study programmers should be conducted to continuously monitor its effects in relevant populations and in comparison with available therapies.

Current disease-modifying treatment of multiple sclerosis

The treatment era for multiple sclerosis began in 1993 with the approval of the first disease-modifying therapy. This changed the management of multiple sclerosis from treating acute exacerbations to focusing on preventive therapeutic options that lessen the risk for exacerbations, changes on magnetic resonance imaging, and disability as measured by the Expanded Disability Status Scale. Currently, there are 8 therapies approved to treat multiple sclerosis: beta-interferons (Avonex, Betaseron, Extavia, and Rebif), fingolimod (Gilenya), glatiramer acetate (Copaxone), mitoxantrone (Novantrone), and natalizumab (Tysabri). These agents will be reviewed including the pivotal trial data, mechanisms of action, and side effects. The timing of beginning therapy and selection of these agents must be individualized for each patient depending upon patient preference, tolerability, clinical and magnetic resonance imaging disease activity, and disease course. All of the current treatments are approved for relapsing disease. To date only the injectable agents, including interferons and glatiramer acetate, have been shown to be of benefit when started after an initial demyelinating event referred to as clinically isolated syndrome. Mitoxantrone was approved for progressive relapsing and secondary progressive multiple sclerosis, although its use is limited by potential risks such as cardiotoxicity and leukemia. Although these agents have made a significant impact on the treatment of multiple sclerosis, they are often only partially effective, so patients may continue to have disease activity. Multiple new agents are currently being tested in clinical trials and it is likely our treatment paradigms will change as more effective therapies become available.

Disease-modifying agents in multiple sclerosis

Since 1993, six disease-modifying therapies for multiple sclerosis (MS) have been proven to be of benefit in rigorous phase III clinical trials. Other agents are also available and are used to treat MS, but definitive data on their efficacy is lacking. Currently, disease-modifying therapy is used for relapsing forms of MS. This includes clinically isolated syndrome/first-attack high-risk patients, relapsing patients, secondary progressive patients who are still experiencing relapses, and progressive relapsing patients. The choice of agent depends upon drug factors (including affordability, availability, convenience, efficacy, and side effects), disease factors (including clinical and neuroimaging prognostic indicators), and patient factors (including comorbidities, lifestyle, and personal preference). This review will discuss the disease-modifying agents used currently in MS, as well as available alternative agents.

IFNβ and glatiramer acetate trigger different signaling pathways to regulate the IL-1 system in multiple sclerosis

Imbalance in cytokine homeostasis plays an important part in the pathogenesis of various chronic inflammatory diseases. In multiple sclerosis (MS), the pro-inflammatory cytokine interleukin-1β (IL-1β) is present in the central nervous system, being expressed mainly in infiltrating macrophages and microglial cells. IL-1β activity is inhibited by the secreted form of IL-1 receptor antagonist (sIL-1Ra) whose production is increased in patients' blood and induced in human monocytes by IFNβ and glatiramer acetate (GA)-both immunomodulators displaying similar therapeutic efficacy in MS. Because intracellular pathways are currently considered as potential therapeutic targets, identification of specific kinases used by both immunomodulators might lead to more specific therapeutic targeting. We addressed the question of intracellular pathways used by IFNβ and GA to induce sIL-1Ra in human monocytes in two recent studies. This addendum to these studies aims at discussing common pathways and different elements used by IFNβ and GA to induce sIL-1Ra in human monocytes. This pinpoints PI3Kδ activation as a requirement to induce sIL-1Ra production downstream monocyte stimulation by either IFNβ or GA. However, the immunomodulators differentially use MEK/ERK pathway to induce sIL-1Ra production in human monocytes. Together, our current studies suggest that PI3Kδ and MEK2 might represent new targets in MS therapy.

Development of oral immunomodulatory agents in the management of multiple sclerosis

The emergence of oral disease-modifying therapies in multiple sclerosis (MS) will have a significant impact on the evolving scenario of immunomodulatory treatments in MS where current therapies are all injectable. Reducing relapses in trials translates for individuals with MS into a therapeutic aim of stopping future events. Thus the possible absence of any perceived benefits to the individual together with the long disease course, variable outcome, and a younger age group affected in MS makes side effects the major issue. The use of disease-modifying therapies as a whole needs to be placed in the context of a widening therapeutic indication where the use of these therapies is being justified at an increasingly early stage and in pre-MS syndromes such as clinically isolated and radiologically isolated syndromes where no fixed disability is likely to have accumulated. The five oral therapies discussed (cladribine, fingolimod, laquinimod, BG-12, and teriflunomide) have just completed Phase III studies and some have just been licensed. New oral drugs for MS need to be placed within this evolving marketplace where ease of delivery together with efficacy and side effects needs to be balanced against the known issues but also the known long-term safety of standard injectables.

FDA-approved preventative therapies for MS: first-line agents

Relapsing-remitting multiple sclerosis is highly variable in its presentation and disease course. The approach to initiating first-line preventative therapies must focus on individualizing treatment strategies. Careful discussion of available treatment options and appropriate expectations regarding outcomes is important to ensure a successful start. Early treatment is recommended, as is on-going monitoring of patients who may choose to forego therapy.

Glatiramer acetate in the treatment of multiple sclerosis: emerging concepts regarding its mechanism of action

Glatiramer acetate is a synthetic, random copolymer widely used as a first-line agent for the treatment of relapsing-remitting multiple sclerosis (MS). While earlier studies primarily attributed its clinical effect to a shift in the cytokine secretion of CD4+ T helper (T(h)) cells, growing evidence in MS and its animal model, experimental autoimmune encephalomyelitis (EAE), suggests that glatiramer acetate treatment is associated with a broader immunomodulatory effect on cells of both the innate and adaptive immune system. To date, glatiramer acetate-mediated modulation of antigen-presenting cells (APC) such as monocytes and dendritic cells, CD4+ T(h) cells, CD8+ T cells, Foxp3+ regulatory T cells and antibody production by plasma cells have been reported; in addition, most recent investigations indicate that glatiramer acetate treatment may also promote regulatory B-cell properties. Experimental evidence suggests that, among these diverse effects, a fostering interplay between anti-inflammatory T-cell populations and regulatory type II APC may be the central axis in glatiramer acetate-mediated immune modulation of CNS autoimmune disease. Besides altering inflammatory processes, glatiramer acetate could exert direct neuroprotective and/or neuroregenerative properties, which could be of relevance for the treatment of MS, but even more so for primarily neurodegenerative disorders, such as Alzheimer's or Parkinson's disease. In this review, we provide a comprehensive and critical overview of established and recent findings aiming to elucidate the complex mechanism of action of glatiramer acetate.

Longitudinal gray matter changes in multiple sclerosis--differential scanner and overall disease-related effects

Voxel-based morphometry (VBM) has been used repeatedly in single-center studies to investigate regional gray matter (GM) atrophy in multiple sclerosis (MS). In multi-center trials, across-scanner variations might interfere with the detection of disease-specific structural abnormalities, thereby potentially limiting the use of VBM. Here we evaluated longitudinally inter-site differences and inter-site comparability of regional GM in MS using VBM. Baseline and follow up 3D T1-weighted magnetic resonance imaging (MRI) data of 248 relapsing-remitting (RR) MS patients, recruited in two clinical centers, (center1/2: n = 129/119; mean age 42.6 ± 10.7/43.3 ± 9.3; male:female 33:96/44:75; median disease duration 150 [72-222]/116 [60-156]) were acquired on two different 1.5T MR scanners. GM volume changes between baseline and year 2 while controlling for age, gender, disease duration, and global GM volume were analyzed. The main effect of time on regional GM volume was larger in data of center two as compared to center one in most of the brain regions. Differential effects of GM volume reductions occurred in a number of GM regions of both hemispheres, in particular in the fronto-temporal and limbic cortex (cluster P corrected <0.05). Overall disease-related effects were found bilaterally in the cerebellum, uncus, inferior orbital gyrus, paracentral lobule, precuneus, inferior parietal lobule, and medial frontal gyrus (cluster P corrected <0.05). The differential effects were smaller as compared to the overall effects in these regions. These results suggest that the effects of different scanners on longitudinal GM volume differences were rather small and thus allow pooling of MR data and subsequent combined image analysis.

Glatiramer acetate treatment of multiple sclerosis: an immunological perspective

Glatiramer acetate (GA) has been used as an immunomodulatory agent for the treatment of relapsing-remitting multiple sclerosis (MS) in the United States since 1996. It is currently one of two first-line agents for use in the treatment of relapsing-remitting MS. GA was the first agent to be used in the treatment of MS that was developed using the animal model of MS called experimental autoimmune encephalomyelitis. In this commentary, we examine the development of GA as a treatment for MS and discuss its mechanism of action as suggested by recent studies using modern immunologic methods.

A critical appraisal of treatment decisions in multiple sclerosis--old versus new

Interferon β and glatiramer acetate have been available for the treatment of multiple sclerosis (MS) for over a decade and their efficacy and safety are well established. These agents have detectable effects on the immune system, but have not been associated with a breakdown of immune surveillance. Novel MS therapies have been approved, or are awaiting approval, that differ from established immunotherapies with regard to their mechanisms of action, modes of administration, adverse-effect profiles and, possibly, the clinical and paraclinical benefits that they may provide for patients. Neurologists will soon be required to make complex treatment decisions with their patients on the basis of very limited clinical data and evidence. Under these circumstances, optimal assessment of risks and benefits will be challenging. In this Review, the anticipated benefits of novel therapies, including reduction in disease activity, possible prevention of disability, and improvement in quality of life, are outlined. In addition, the current acceptance of potential risks--including serious or even life-threatening adverse effects, the likelihood of which may rise with increased cumulative exposure to a particular agent--by patients with MS will be reviewed.

Managing relapsing–remitting multiple sclerosis following first drug failure

SUMMARY IFN-β and glatiramer acetate are the usual first-line treatments for cases of relapsing–remitting multiple sclerosis. As both of these agents are only partially effective in controlling disease activity, ‘breakthrough’ disease is common. Deciding how much breakthrough constitutes a treatment failure necessitating a switch in therapy is now a common problem that most clinicians will encounter in practice. In this article we will discuss the approach to deciding when treatment failure occurs and the strategies that can be used to tackle this problem.

Definitions of breakthrough disease and second-line agents

Conventional disease-modifying agents are only moderately effective, so breakthrough disease activity is commonly seen. The evidence from randomized clinical trials and real-world observational data supporting the use of the second-line agents natalizumab, mitoxantrone, and cyclophosphamide are reviewed. Potential future treatment options are also discussed. Management algorithms for breakthrough disease are outlined.

Interferon-β but not Glatiramer acetate stimulates CXCL10 secretion in primary cultures of thyrocytes: a clue for understanding the different risks of thyroid dysfunctions in patients with multiple sclerosis treated with either of the two drugs

Autoimmune thyroid disease (AITD) has been reported in patients with multiple sclerosis (MS) receiving interferon-beta (IFN-β), but not in those receiving Glatiramer acetate (GA). CXCL10 is a chemokine playing a pathogenetic role in AITD and MS. Our aim was to evaluate the effects on CXCL10 secretion of IFN-β and GA, alone and in combination with TNF-α, in primary cultures of thyrocytes (PCT). Significant and dose-dependent secretions of CXCL10 were induced by IFN-β but not GA. TNF-α synergistically increased IFN-β induced CXCL10 secretion. These results may provide an explanation for the occurrence of AITD during IFN-β, but not during GA, treatment for MS.

Management of breakthrough disease in patients with multiple sclerosis: when an increasing of Interferon beta dose should be effective?

Background

In daily clinical setting, some patients affected by relapsing-remitting Multiple Sclerosis (RRMS) are switched from the low-dose to the high-dose Interferon beta (IFNB) in order to achieve a better control of the disease.

Purpose

In this observational, post-marketing study we reported the 2-year clinical outcomes of patients switched to the high-dose IFNB; we also evaluated whether different criteria adopted to switch patients had an influence on the clinical outcomes.

Methods

Patients affected by RRMS and switched from the low-dose to the high-dose IFNB due to the occurrence of relapses, or contrast-enhancing lesions (CELs) as detected by yearly scheduled MRI scans, were followed for two years. Expanded Disability Status Scale (EDSS) scores, as well as clinical relapses, were evaluated during the follow-up period.

Results

We identified 121 patients switched to the high-dose IFNB. One hundred patients increased the IFNB dose because of the occurrence of one or more relapses, and 21 because of the presence of one or more CELs, even in absence of clinical relapses. At the end of the 2-year follow-up, 72 (59.5%) patients had a relapse, and 51 (42.1%) reached a sustained progression on EDSS score. Overall, 85 (70.3%) patients showed some clinical disease activity (i.e. relapses or disability progression) after the switch.

Relapse risk after increasing the IFNB dose was greater in patients who switched because of relapses than those switched only for MRI activity (HR: 5.55, p = 0.001). A high EDSS score (HR: 1.77, p < 0.001) and the combination of clinical and MRI activity at switch raised the risk of sustained disability progression after increasing the IFNB dose (HR: 2.14, p = 0.01).

Conclusion

In the majority of MS patients, switching from the low-dose to the high-dose IFNB did not reduce the risk of further relapses or increased disability in the 2-year follow period.

Although we observed that patients who switched only on the basis on MRI activity (even in absence of clinical attacks) had a lower risk of further relapses, larger studies are warranted before to recommend a switch algorithm based on MRI findings.

Effect of disease-modifying drugs on cortical lesions and atrophy in relapsing-remitting multiple sclerosis

OBJECTIVE

To measure the effects of disease-modifying drugs (DMDs) on the development of cortical lesions (CL) and cortical atrophy in patients with relapsing-remitting multiple sclerosis (RRMS).

METHODS

RRMS patients (n = 165) were randomized to subcutaneous (sc) interferon (IFN) beta-1a (44 mcg three times weekly), intramuscular (im) IFN beta-1a (30 mcg weekly) or glatiramer acetate (GA; 20 mg daily). The reference population comprised 50 untreated patients. Clinical and MRI examinations were performed at baseline, 12 months and 24 months.

RESULTS

One hundred and forty-one treated patients completed the study. After 12 months, 37/50 (74%) of untreated patients developed ≥ 1 new CL (mean 1.6), compared with 30/47 (64%) of im IFN beta-1a-treated patients (mean 1.2, p = 0.021), 24/48 (50%) of GA-treated patients (mean 0.8, p = 0.001) and 12/46 (26%) of sc IFN beta-1a-treated patients (mean 0.4, p < 0.001). After 24 months, ≥ 1 new CL was observed in 41/50 (82%) of untreated (mean 3.0), 34/47 (72%) of im IFN beta-1a-treated (mean 1.6, p < 0.001), 30/48 (62%) of GA-treated (mean 1.3, p < 0.001) and 24/46 (52%) of sc IFN beta-1a-treated patients (mean 0.8, p < 0.001). Mean grey matter fraction decrease in DMD-treated patients at 24 months ranged from 0.7 to 0.8 versus 1.0 in untreated patients (p = 0.023).

CONCLUSIONS

Disease-modifying drugs significantly decreased new CL development and cortical atrophy progression compared with untreated patients, with faster and more pronounced effects seen with sc IFN beta-1a than with im IFN beta-1a or GA.

Evidence-based assessment of potential use of fingolimod in treatment of relapsing multiple sclerosis

Multiple sclerosis is an autoimmune inflammatory demyelinating disease of the central nervous system and represents one of the most common causes of chronic neurologic disability in young adults. All the current disease-modifying drugs are administered parenterally, and can be associated with varying degrees of injection site or infusion-related reactions. Together with other side effects, the parenteral route of administration is one of the key factors affecting adherence to therapy in multiple sclerosis. Fingolimod (FTY720) is an immunomodulator that acts on sphingosine 1-phosphate (S1P) receptors and is the first oral drug approved by the US Food and Drug Administration for the treatment of relapsing-remitting multiple sclerosis. Downmodulation of S1P receptor type 1 (S1P₁) slows the egress of lymphocytes from lymph nodes and recirculation to the central nervous system, reduces astrogliosis, and inhibits angiogenesis during chronic neuroinflammation. Fingolimod also regulates the migration of B cells and dendritic cells, and enhances endothelial barrier function. Results from Phase II and III clinical trials provide robust evidence of the efficacy of fingolimod in relapsing-remitting multiple sclerosis. While some caution should be exercised in terms of safety issues, the introduction of fingolimod represents a great advance in the treatment of relapsing-remitting multiple sclerosis. The pharmacologic data on fingolimod and its efficacy and safety in multiple sclerosis are reviewed in this paper.

The relationship between alternative medication possession ratio thresholds and outcomes: evidence from the use of glatiramer acetate

OBJECTIVE

To examine how changes in the medication possession ratio (MPR) affect the probability of multiple sclerosis (MS) relapses and total and MS-related charges among patients treated with glatiramer acetate (GA).

METHODS

Data were obtained from i3 InVision™ Data Mart for January 1, 2006 through March 31, 2010. Patients were included if they were diagnosed with MS, initiated therapy with GA, and had continuous insurance coverage from 6 months prior through 24 months after initial use of GA (n=839). Multivariate regressions which controlled for patient characteristics examined the association between achievement of alternative MPR goals and patient relapses and charges.

RESULTS

Patients who achieved an MPR of at least 0.7 had significantly lower odds of relapse than those with MPR thresholds below 0.7, with achievement of a threshold of 0.7, 0.8, or 0.9, associated with an odds ratio of relapse of 0.545 (95% CI=0.351-0.824), 0.568 (95% CI=0.371-0.870), and 0.421 (95% CI=0.260-0.679), respectively. Attaining higher MPR thresholds resulted in larger reductions in direct medical charges, excluding GA and other MS-related drugs. MPR of 0.25 was associated with $1699 lower 2-year total direct medical charges (p=0.009) while a threshold of 0.95 was associated with $2136 lower total charges (p<0.001), compared to patients not reaching these respective thresholds. MPR of 0.90 was associated with $986 lower MS-related charges than for those with MPR<0.90 (p=0.050). Results also revealed an association between patient adherence to GA and statistically significant reductions in charges for specific components of care.

LIMITATIONS

Results are generalizable only to patients with medical and prescription benefit coverage without regard for functional status.

CONCLUSIONS

As adherence improved the odds of relapse decreased and charge offsets generally increased. Results suggest that, despite higher costs associated with increased usage of GA, patient outcomes are improved and there are cost-offsets associated with adherent use of GA.

Multiple Sklerose

Die multiple Sklerose (MS) ist eine der häufigsten neurologischen Erkrankungen, für deren Ursache es bislang keine einheitliche Erklärung gibt. Grundpfeiler der Diagnostik ist die Klinik, ergänzt durch die Magnetresonanztomographie (MRT). Eine Liquoruntersuchung zum Nachweis der entzündlichen Genese nachgewiesener multifokaler Störungen ist bei allen unklaren Fällen und bei älteren Patienten erforderlich. Zur Bestätigung und Verlaufskontrolle sind elektrophysiologische Verfahren hilfreich.

[Interferon β for multiple sclerosis. How much is good enough?]

Interferon β-1b (IFNB-1b, Betaferon®) was the first therapy for multiple sclerosis (MS) showing efficacy in a randomized controlled clinical trial. Early studies suggested a dose-dependency of the clinical efficacy of IFNB-1b. However, until recently no reliable clinical data were available to assess the potential of higher dosing to increase therapeutic efficacy. In addition, no clinical trials have been conducted to directly compare the efficacy of IFNB-1b with that of glatiramer acetate, an alternative first line treatment option for relapsing-remitting MS. Just recently, the prospective, randomized, multicenter study BEYOND was published which addressed both issues. In this review the BEYOND trial is reviewed and placed in the context of advantages and disadvantages of currently available first line therapies for MS.

Population structure and HLA DRB1 1501 in the response of subjects with multiple sclerosis to first-line treatments

Using retrospectively collected outcome data for treatment naïve subjects treated with either glatiramer acetate (GA) (n=332) or interferon beta (IFN β) (n=424), we replicated the lack of a significant difference in efficacy between these treatments. Further, for both treatments, we observed a decline in the hazard of a relapse over time, which may suggest the existence of subsets of subjects with differential responses to each treatment. The HLA DRB1 1501 allele explained some of this variation in event-free survival while on GA, and we found suggestive evidence that an IRF8 polymorphism influences event-free survival in IFN β treated subjects.

Potential short-term use of oral cladribine in treatment of relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic, immune-mediated disorder of the central nervous system. The clinical course of MS varies among patients. Currently, interferon (IFN) products, including IFN β-1a administered intramuscularly or subcutaneously and IFN β-1b subcutaneously, glatiramer acetate, natalizumab, and mitoxantrone are approved disease-modifying therapies for the treatment of relapsing-remitting MS. Cladribine, also known as 2-chlorodeoxyadenosine, is a synthetic adenosine deaminase-resistant purine nucleoside analog that preferentially depletes lymphocyte subpopulations. This sustained effect on lymphocytes is advantageous for patients with MS. CLARITY (CLAdRIbine Tablets Treating MS OrallY), a Phase III trial, has demonstrated that short-term oral cladribine decreases relapse rates and risk of disability progression in comparison with placebo. Cladribine was well tolerated in the study, with the most common adverse effects being headache, nausea, upper respiratory tract infections, and lymphocytopenia. An ongoing study is evaluating the efficacy and safety of the combination of oral cladribine and IFN-β products. A further ongoing study is examining the use of oral cladribine in clinically isolated syndrome and time to conversion to MS. Although the results of CLARITY are promising, the exact role of oral cladribine may be better defined with the completion of ongoing studies.

Glatiramer acetate triggers PI3Kδ/Akt and MEK/ERK pathways to induce IL-1 receptor antagonist in human monocytes

Glatiramer acetate (GA), an immunomodulator used in multiple sclerosis (MS) therapy, induces the production of secreted IL-1 receptor antagonist (sIL-1Ra), a natural inhibitor of IL-1β, in human monocytes, and in turn enhances sIL-1Ra circulating levels in MS patients. GA is a mixture of peptides with random Glu, Lys, Ala, and Tyr sequences of high polarity and hydrophilic nature that is unlikely to cross the blood-brain barrier. In contrast, sIL-1Ra crosses the blood-brain barrier and, in turn, may mediate GA anti-inflammatory activities within the CNS by counteracting IL-1β activities. Here we identify intracellular signaling pathways induced by GA that control sIL-1Ra expression in human monocytes. By using kinase knockdown and specific inhibitors, we demonstrate that GA induces sIL-1Ra production via the activation of PI3Kδ, Akt, MEK1/2, and ERK1/2, demonstrating that both PI3Kδ/Akt and MEK/ERK pathways rule sIL-1Ra expression in human monocytes. The pathways act in parallel upstream glycogen synthase kinase-3α/β (GSK3α/β), the knockdown of which enhances sIL-1Ra production. Together, our findings demonstrate the existence of signal transduction triggered by GA, further highlighting the mechanisms of action of this drug in MS.