Glatiramer acetate: evidence for a dual mechanism of action

Glatiramer Acetate Immunomodulation: Evidence of Neuroprotection and Cognitive Preservation

Novel, neuroprotective uses of Copaxone (generic name: glatiramer acetate—GA) are being examined, primarily in neurological conditions involving cognitive decline. GA is a well-studied synthetic copolymer that is FDA-approved for immune-based treatment of relapsing remitting multiple sclerosis (RRMS). Clinical studies have explored the potential mechanism of action (MOA) and outcomes of GA immunization in patients. Furthermore, results from these and animal studies suggest that GA has a direct immunomodulatory effect on adaptive and innate immune cell phenotypes and responses. These MOAs have been postulated to have a common neuroprotective impact in several neuroinflammatory and neurodegenerative diseases. Notably, several clinical studies report that the use of GA mitigated MS-associated cognitive decline. Its propensity to ameliorate neuro-proinflammatory and degenerative processes ignites increased interest in potential alternate uses such as in age-related macular degeneration (AMD), amyotrophic lateral sclerosis (ALS), and Alzheimer’s disease (AD). Preclinical studies are exploring less frequent subcutaneous administration of GA, such as once weekly or monthly or a single dosing regimen. Indeed, cognitive functions were found to be either preserved, reversed, or improved after the less frequent treatment regimens with GA in animal models of AD. In this systematic review, we examine the potential novel uses of GA across clinical and pre-clinical studies, with evidence for its beneficial impact on cognition. Future investigation in large-size, double-blind clinical trials is warranted to establish the impact of GA immunomodulation on neuroprotection and cognitive preservation in various neurological conditions.

Acting centrally or peripherally: A renewed interest in the central nervous system penetration of disease-modifying drugs in multiple sclerosis

With the recent approval of cladribine tablets, siponimod and ozanimod, there has been a renewed interest into the extent to which these current generation disease-modifying therapies (DMTs) are able to cross into the central nervous system (CNS), and how this penetration of the blood-brain barrier (BBB) may influence their ability to treat multiple sclerosis (MS). The integrity of the CNS is maintained by the BBB, blood-cerebrospinal fluid barrier, and the arachnoid barrier, which all play an important role in preserving the immunological environment and homeostasis within the CNS. The integrity of the BBB decreases during the course of MS, with a putative temporal relationship to disease worsening. Furthermore, it is currently considered that progression of the disease is mediated mainly by resident cells of the CNS. The existing literature provides evidence to show that some of the current generation DMTs for MS are able to penetrate the CNS and potentially exert direct effects on CNS-resident cells, in particular the CNS-penetrating prodrugs cladribine and fingolimod, and other sphingosine-1 phosphate receptor modulators; siponimod and ozanimod. Other current generation DMTs appear to be restricted to the periphery due to their high molecular weight or physicochemical properties. As more effective brain penetrant therapies are developed for the treatment of MS, there is a need to understand whether the potential for direct effects within the CNS are of significance, and whether this brings additional benefits over and above treatment effects mediated in the periphery. In turn, this will require an improved understanding of the structure and function of the BBB, the role it plays in MS and subsequent treatments. This narrative review summarizes the data supporting the biological plausibility of a potential benefit from therapeutic molecules entering the CNS, and discusses the potential significance in the current and future treatment of MS.

Can FDA-Approved Immunomodulatory Drugs be Repurposed/Repositioned to Alleviate Chronic Pain?

Pain is among the most widespread chronic health condition confronting society today and our inability to manage chronic pain contributes to the opioid abuse epidemic in America. The immune system is known to contribute to acute and chronic pain, but only limited therapeutic treatments such as non-steroid anti-inflammatory drugs have resulted from this knowledge. The last decade has shed light on neuro-immune interactions mediating the development, maintenance, and resolution of chronic pain. Here, we do not aim to perform a comprehensive review of all immune mechanisms involved in chronic pain, but to briefly review the contribution of the main cytokines and immune cells (macrophages, microglia, mast cells and T cells) to chronic pain. Given the urgent need to address the Pain crisis, we provocatively propose to repurpose/reposition FDA-approved immunomodulatory drugs for their potential to alleviate chronic pain. Repositioning or repurposing offers an attractive way to accelerate the arrival of new analgesics.

Randomized peptide assemblies for enhancing immune responses to nanomaterials

Biomaterials capable of inducing immune responses with minimal associated inflammation are of interest in applications ranging from tissue repair to vaccines. Here we report the design of self-assembling randomized polypeptide nanomaterials inspired by glatiramoids, an immunomodulatory class of linear random copolymers. We hypothesized that peptide self-assemblies bearing similar randomized polypeptides would similarly raise responses skewed toward Type 2 immunity and T_H2 T-cell responses, additionally strengthening responses to co-assembled peptide epitopes in the absence of adjuvant. We developed a method for synthesizing self-assembling peptides terminated with libraries of randomized polypeptides (termed KEYA) with good batch-to-batch reproducibility. These peptides formed regular nanofibers and raised strong antibody responses without adjuvants. KEYA modifications dramatically improved uptake of peptide nanofibers in vitro by antigen presenting cells, and served as strong B-cell and T-cell epitopes in vivo, enhancing immune responses against epitopes relevant to influenza and chronic inflammation while inducing a KEYA-specific Type 2/T_H2/IL-4 phenotype. KEYA modifications also increased IL-4 production by T cells, extended the residence time of nanofibers, induced no measurable swelling in footpad injections, and decreased overall T cell expansion compared to unmodified nanofibers, further suggesting a T_H2 T-cell response with minimal inflammation. Collectively, this work introduces a biomaterial capable of raising strong Type 2/T_H2/IL-4 immune responses, with potential applications ranging from vaccination to tissue repair.

T Cells as an Emerging Target for Chronic Pain Therapy

The immune system is critically involved in the development and maintenance of chronic pain. However, T cells, one of the main regulators of the immune response, have only recently become a focus of investigations on chronic pain pathophysiology. Emerging clinical data suggest that patients with chronic pain have a different phenotypic profile of circulating T cells compared to controls. At the preclinical level, findings on the function of T cells are mixed and differ between nerve injury, chemotherapy, and inflammatory models of persistent pain. Depending on the type of injury, the subset of T cells and the sex of the animal, T cells may contribute to the onset and/or the resolution of pain, underlining T cells as a major player in the transition from acute to chronic pain. Specific T cell subsets release mediators such as cytokines and endogenous opioid peptides that can promote, suppress, or even resolve pain. Inhibiting the pain-promoting functions of T cells and/or enhancing the beneficial effects of pro-resolution T cells may offer new disease-modifying strategies for the treatment of chronic pain, a critical need in view of the current opioid crisis.

Effect of switching from glatiramer acetate 20 mg/daily to glatiramer acetate 40 mg three times a week on gray and white matter pathology in subjects with relapsing multiple sclerosis: A longitudinal DTI study

BACKGROUND

Glatiramer acetate (GA) 40 mg × 3/weekly was approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). While the beneficial effect of GA 20 mg/daily in MS patients on non-conventional MRI measures has been demonstrated, the effect of GA 40 mg × 3/weekly at the microstructural tissue level has yet to be explored.

OBJECTIVE

To investigate the effect of switching from GA 20 mg/daily to GA 40 mg × 3/weekly on the evolution of microstructural changes in the thalamus and normal appearing white matter (NAWM), using diffusion tensor imaging (DTI).

METHODS

In this observational, longitudinal, cross-over, 34-month MRI study, we recruited 150 RRMS patients that underwent MRI 12-18 months before switching (pre-index), during the switch (index) and 12-18 months after switching (post-index) from GA 20 mg/daily to GA 40 mg × 3/weekly. Regional DTI metrics and tract-based spatial statistics (TBSS) analyses were performed. Mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) and fractional anisotropy (FA) were measured in thalamus and NAWM.

RESULTS

Regional DTI measures, measures of whole brain, white and gray matter, and thalamus volumes, as well as lesion volume, showed no significant changes. However, the voxel-wise TBSS analysis showed increased FA both in the NAWM and thalamus, as well as increased MD and AD in NAWM, and decreased RD in NAWM (p < .05). Areas of increased FA and MD as well as decreased RD in the NAWM, and increased AD both in the NAWM and thalamus were detected between index to post-index (p < .05).

CONCLUSIONS

This study confirms a comparable effect of GA 40 mg × 3/weekly to GA 20 mg/daily on DTI measures over 34 months.

Biomaterial strategies for generating therapeutic immune responses

Biomaterials employed to raise therapeutic immune responses have become a complex and active field. Historically, vaccines have been developed primarily to fight infectious diseases, but recent years have seen the development of immunologically active biomaterials towards an expanding list of non-infectious diseases and conditions including inflammation, autoimmunity, wounds, cancer, and others. This review structures its discussion of these approaches around a progression from single-target strategies to those that engage increasingly complex and multifactorial immune responses. First, the targeting of specific individual cytokines is discussed, both in terms of delivering the cytokines or blocking agents, and in terms of active immunotherapies that raise neutralizing immune responses against such single cytokine targets. Next, non-biological complex drugs such as randomized polyamino acid copolymers are discussed in terms of their ability to raise multiple different therapeutic immune responses, particularly in the context of autoimmunity. Last, biologically derived matrices and materials are discussed in terms of their ability to raise complex immune responses in the context of tissue repair. Collectively, these examples reflect the tremendous diversity of existing approaches and the breadth of opportunities that remain for generating therapeutic immune responses using biomaterials.

Glatiramer acetate attenuates the activation of CD4+ T cells by modulating STAT1 and -3 signaling in glia

Interactions between immune effector cells of the central nervous system appear to directly or indirectly influence the progress/regression of multiple sclerosis (MS). Here, we report that glial STAT1 and -3 are distinctively phosphorylated following the interaction of activated lymphocytes and glia, and this effect is significantly inhibited by glatiramer acetate (GA), a disease-modifying drug for MS. GA also reduces the activations of STAT1 and -3 by MS-associated stimuli such as IFNγ or LPS in primary glia, but not neurons. Experiments in IFNγ- and IFNγ receptor-deficient mice revealed that GA-induced inhibitions of STAT signaling are independent of IFNγ and its receptor. Interestingly, GA induces the expression levels of suppressor of cytokine signaling-1 and -3, representative negative regulators of STAT signaling in glia. We further found that GA attenuates the LPS-triggered enhancement of IL-2, a highly produced cytokine in patients with active MS, in CD4+ T cells co-cultured with glia, but not in CD4+ T cells alone. Collectively, these results provide that activation of glial STATs is an essential event in the interaction between glia and T cells, which is a possible underlying mechanism of GA action in MS. These findings provide an insight for the development of targeted therapies against MS.

Metabolic response to glatiramer acetate therapy in multiple sclerosis patients

Glatiramer acetate (GA; Copaxone) is a random copolymer of glutamic acid, lysine, alanine, and tyrosine used for the treatment of patients with multiple sclerosis (MS). Its mechanism of action has not been already fully elucidated, but it seems that GA has an immune-modulatory effect and neuro-protective properties. Lymphocyte mitochondrial dysfunction underlines the onset of several autoimmune disorders. In MS first diagnosis patients, CD4⁺, the main T cell subset involved in the pathogenesis of MS, undergo a metabolic reprogramming that consist in the up-regulation of glycolysis and in the down-regulation of oxidative phosphorylation. Currently, no works exist about CD4⁺ T cell metabolism in response to GA treatment. In order to provide novel insight into the potential use of GA in MS treatment, blood samples were collected from 20 healthy controls (HCs) and from 20 RR MS patients prior and every 6 months during the 12 months of GA administration. GA treated patients' CD4⁺ T cells were compared with those from HCs analysing their mitochondrial activity through polarographic and enzymatic methods in association with their antioxidant status, through the analysis of SOD, GPx and CAT activities. Altogether, our findings suggest that GA is able to reduce CD4⁺ T lymphocytes' dysfunctions by increasing mitochondrial activity and their response to oxidative stress.

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GA is able to reduce CD4 + T cell's dysfunctions in MS patients;

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A CD4 + T cell metabolic response in GA treated patients is proposed;

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Metabolic response relies on changes in mitochondrial activity and in antioxidative status.

IL-27: a potential biomarker for responders to glatiramer acetate therapy

Glatiramer acetate (GA) is an FDA-approved efficacious drug for the treatment of relapsing-remitting multiple sclerosis (RRMS). However, this treatment is not effective for all RRMS patients. Therefore, it is important to identify reliable biomarkers that can predict a beneficial clinical response to GA therapy. Since an increase in IL-27 has been demonstrated to suppress autoimmune and allergic diseases of inflammatory origin, we examined the effect of GA on the production of IL-27. We observed that IL-27 production in PBMCs cultured with GA was heterogeneous amongst MS patients and healthy donors (HD), and thus, defined these MS patients as either efficient, weak, or non-IL-27 producers. Interestingly, GA could induce the expression of the IL-27p28 subunit more efficiently than the IL-27 EBI3 subunit, and the production of IL-27 depended on MHC class II binding by GA. In addition, we found that GA could augment Toll-like receptor (TLR)-mediated IL-27 production. Importantly, serum production of IL-27 and IL-10 was significantly increased at 6months during GA therapy in clinical responders to GA, but not in GA non-responders. Altogether, our data suggest that GA-induced IL-27 may represent a therapeutic mechanism of GA-mediated immunomodulation and that GA-mediated IL-27 production in PBMCs is worth exploring as a biomarker to screen for GA responders prior to the initiation of GA treatment.

Effectiveness of glatiramer acetate compared to other multiple sclerosis therapies

OBJECTIVE

To assess the effectiveness of glatiramer acetate (GA) compared to other multiple sclerosis (MS) therapies in routine clinical practice.

MATERIALS AND METHODS

Observational cohort study carried out in MS patients treated with GA (GA cohort) or other MS therapies -switched from GA- (non-GA cohort). Study data were obtained through review of our MS patient database. The primary endpoint was the Expanded Disability Status Scale (EDSS) scores reached at the end of treatment/last check-up.

RESULTS

A total of 180 patients were included: GA cohort n = 120, non-GA cohort n = 60. Patients in the GA cohort showed better EDSS scores at the end of treatment/last check-up (mean ± SD, 2.8 ± 1.8 vs. 3.9 ± 2.2; P = 0.001) and were 1.65 times more likely to show better EDSS scores compared to the non-GA cohort (odds ratio, 0.606; 95%CI, 0.436-0.843; P = 0.003). Patients in the GA cohort showed longer mean time to reach EDSS scores of 6 (209.1 [95%CI, 187.6-230.6] vs. 164.3 [95% CI, 137.0-191.6] months; P = 0.004) and slower disability progression (hazard ratio, 0.415 [95%CI, 0.286-0.603]; P < 0.001). The annualized relapse rate was lower in the GA cohort (mean ± SD, 0.5 ± 0.5 vs. 0.8 ± 0.5; P = 0.001) and patients' quality of life was improved in this study cohort compared to the non-GA cohort (mean ± SD, 0.7 ± 0.1 vs. 0.6 ± 0.2; P = 0.01).

CONCLUSIONS

GA may slow down the progression of EDSS scores to a greater extent than other MS therapies, as well as achieving a greater reduction in relapses and a greater improvement in patients' quality of life. Switching from GA to other MS therapies has not proved to entail a better response to treatment.

Glatiramer Acetate 40 mg/mL in Relapsing-Remitting Multiple Sclerosis: A Review

Glatiramer acetate (Copaxone(®)) is a synthetic analogue of myelin basic protein, which is thought to be involved in the pathogenesis of multiple sclerosis (MS). The therapeutic effects of the drug in the treatment of MS are thought to be via immunomodulation and neuroprotection. Subcutaneous glatiramer acetate 20 mg/mL once daily is approved in several countries for the treatment of relapsing forms of MS. Recently, a high-concentration formulation of glatiramer acetate 40 mg/mL administered three times weekly was approved in the USA and several European countries in the same indication. This article reviews the efficacy and tolerability of the high-concentration regimen. In the randomized, phase III GALA study in patients with relapsing-remitting MS (RRMS), glatiramer acetate 40 mg/mL three times weekly reduced annualized relapse rates significantly more than placebo, and indirect comparisons indicate that the efficacy of the three-times-weekly regimen is similar to that of the 20 mg/mL once-daily regimen. Results of the randomized, phase IIIb GLACIER study in patients with RRMS demonstrated that the three-times-weekly regimen reduced the risk of injection-site reactions by 50 % and was associated with numerically greater patient convenience scores than the once-daily regimen. Thus, in the treatment of RRMS, glatiramer acetate 40 mg/mL three times weekly is effective and provides a better tolerated and possibly more convenient option than the once-daily regimen.

Therapeutic approaches to disease modifying therapy for multiple sclerosis in adults: an Australian and New Zealand perspective: part 1 historical and established therapies. MS Neurology Group of the Australian and New Zealand Association of Neurologists

Multiple sclerosis (MS) is a potentially life-changing immune mediated disease of the central nervous system. Until recently, treatment has been largely confined to acute treatment of relapses, symptomatic therapies and rehabilitation. Through persistent efforts of dedicated physicians and scientists around the globe for 160 years, a number of therapies that have an impact on the long term outcome of the disease have emerged over the past 20 years. In this three part series we review the practicalities, benefits and potential hazards of each of the currently available and emerging treatment options for MS. We pay particular attention to ways of abrogating the risks of these therapies and provide advice on the most appropriate indications for using individual therapies. In Part 1 we review the history of the development of MS therapies and its connection with the underlying immunobiology of the disease. The established therapies for MS are reviewed in detail and their current availability and indications in Australia and New Zealand are summarised. We examine the evidence to support their use in the treatment of MS.

Codelivery of antigen and an immune cell adhesion inhibitor is necessary for efficacy of soluble antigen arrays in experimental autoimmune encephalomyelitis

Autoimmune diseases such as multiple sclerosis (MS) are typified by the misrecognition of self-antigen and the clonal expansion of autoreactive T cells. Antigen-specific immunotherapies (antigen-SITs) have long been explored as a means to desensitize patients to offending self-antigen(s) with the potential to retolerize the immune response. Soluble antigen arrays (SAgAs) are composed of hyaluronic acid (HA) cografted with disease-specific autoantigen (proteolipid protein peptide) and an ICAM-1 inhibitor peptide (LABL). SAgAs were designed as an antigen-SIT that codeliver peptides to suppress experimental autoimmune encephalomyelitis (EAE), a murine model of MS. Codelivery of antigen and cell adhesion inhibitor (LABL) conjugated to HA was essential for SAgA treatment of EAE. Individual SAgA components or mixtures thereof reduced proinflammatory cytokines in cultured splenocytes from EAE mice; however, these treatments showed minimal to no in vivo therapeutic effect in EAE mice. Thus, carriers that codeliver antigen and a secondary “context” signal (e.g., LABL) in vivo may be an important design criteria to consider when designing antigen-SIT for autoimmune therapy.

Targeting insulin-like growth factor 1 leads to amelioration of inflammatory demyelinating disease

In patients with multiple sclerosis (MS) and in mice with experimental autoimmune encephalomyelitis (EAE), proliferating autoreactive T cells play an important role in the pathogenesis of the disease. Due to the importance of these myelin-specific T cells, these cells have been therapeutic targets in a variety of treatments. Previously we found that Lenaldekar (LDK), a novel small molecule, could inhibit exacerbations in a preclinical model of MS when given at the start of an EAE exacerbation. In those studies, we found that LDK could inhibit human T cell recall responses and murine myelin responses in vitro. In these new studies, we found that LDK could inhibit myelin specific T cell responses through the insulin-like growth factor-1 receptor (IGF-1R) pathway. Alteration of this pathway led to marked reduction in T cell proliferation and expansion. Blocking this pathway could account for the observed decreases in clinical signs and inflammatory demyelinating disease, which was accompanied by axonal preservation. Our data indicate that IGF-1R could be a potential target for new therapies for the treatment of autoimmune diseases where autoreactive T cell expansion is a requisite for disease.

Two decades of subcutaneous glatiramer acetate injection: current role of the standard dose, and new high-dose low-frequency glatiramer acetate in relapsing-remitting multiple sclerosis treatment

Glatiramer acetate, a synthetic amino acid polymer analog of myelin basic protein, is one of the first approved drugs for the treatment of relapsing-remitting multiple sclerosis. Several clinical trials have shown consistent and sustained efficacy of glatiramer acetate 20 mg subcutaneously daily in reducing relapses and new demyelinating lesions on magnetic resonance imaging in patients with relapsing-remitting multiple sclerosis, as well as comparable efficacy to high-dose interferon beta. Some preclinical and clinical data suggest a neuroprotective role for glatiramer acetate in multiple sclerosis. Glatiramer acetate is associated with a relatively favorable side-effect profile, and importantly this was confirmed also during long-term use. Glatiramer acetate is the only multiple sclerosis treatment compound that has gained the US Food and Drug Administration pregnancy category B. All these data support its current use as a first-line treatment option for patients with clinical isolated syndrome or relapsing-remitting multiple sclerosis. More recent data have shown that high-dose glatiramer acetate (ie, 40 mg) given three times weekly is effective, safe, and well tolerated in the treatment of relapsing-remitting multiple sclerosis, prompting the approval of this dosage in the US in early 2014. This high-dose, lower-frequency glatiramer acetate might represent a new, more convenient regimen of administration, and this might enhance patients' adherence to the treatment, crucial for optimal disease control.

Impact of pregabalin treatment on synaptic plasticity and glial reactivity during the course of experimental autoimmune encephalomyelitis

BACKGROUND

Multiple sclerosis (MS) is an autoimmune and neurodegenerative disease that affects young adults. It is characterized by generating a chronic demyelinating autoimmune inflammation in the central nervous system. An experimental model for studying MS is the experimental autoimmune encephalomyelitis (EAE), induced by immunization with antigenic proteins from myelin.

AIMS

The present study investigated the evolution of EAE in pregabalin treated animals up to the remission phase.

METHODS AND RESULTS

The results demonstrated a delay in the onset of the disease with statistical differences at the 10th and the 16th day after immunization. Additionally, the walking track test (CatWalk) was used to evaluate different parameters related to motor function. Although no difference between groups was obtained for the foot print pressure, the regularity index was improved post treatment, indicating a better motor coordination. The immunohistochemical analysis of putative synapse preservation and glial reactivity revealed that pregabalin treatment improved the overall morphology of the spinal cord. A preservation of circuits was depicted and the glial reaction was downregulated during the course of the disease. qRT-PCR data did not show immunomodulatory effects of pregabalin, indicating that the positive effects were restricted to the CNS environment.

CONCLUSIONS

Overall, the present data indicate that pregabalin is efficient for reducing the seriousness of EAE, delaying its course as well as reducing synaptic loss and astroglial reaction.

Glatiramer acetate: a review of its use in patients with relapsing-remitting multiple sclerosis and in delaying the onset of clinically definite multiple sclerosis

Glatiramer acetate (Copaxone(®)) is a synthetic analogue of the multiple sclerosis (MS)-associated antigen, myelin basic protein. Although its exact mechanisms of action in MS remain to be fully elucidated, the key mechanisms of action of glatiramer acetate appear to be modulation of the inflammatory response and neuroprotective and/or neuroregenerative effects. Subcutaneous glatiramer acetate is indicated for the treatment of adult patients with relapsing-remitting MS (RRMS) and the treatment of patients who have experienced a well-defined first clinical episode and have magnetic resonance imaging (MRI) features consistent with MS or have been determined to be at high risk of developing clinically definite MS (CDMS). In clinical trials in patients with RRMS, glatiramer acetate reduced the frequency of relapses and reduced the burden and activity of disease on MRI, was more effective than placebo and showed generally similar efficacy to subcutaneous interferon (IFN) β-1a and IFNβ-1b. Furthermore, the beneficial effects of glatiramer acetate were sustained during up to 15 years of treatment in an extension study. In patients with clinically isolated syndrome (CIS), glatiramer acetate significantly delayed the onset of CDMS compared with placebo. The drug was generally well tolerated in these patient populations, with injection-site reactions being the most commonly occurring adverse events. Therefore, glatiramer acetate remains a valuable first-line option in the treatment of RRMS and is an option for delaying the onset of CDMS in patients with CIS.

Glatiramer acetate treatment effects on gene expression in monocytes of multiple sclerosis patients

Background

Glatiramer acetate (GA) is a mixture of synthetic peptides used in the treatment of patients with relapsing-remitting multiple sclerosis (RRMS). The aim of this study was to investigate the effects of GA therapy on the gene expression of monocytes.

Methods

Monocytes were isolated from the peripheral blood of eight RRMS patients. The blood was obtained longitudinally before the start of GA therapy as well as after one day, one week, one month and two months. Gene expression was measured at the mRNA level by microarrays.

Results

More than 400 genes were identified as up-regulated or down-regulated in the course of therapy, and we analyzed their biological functions and regulatory interactions. Many of those genes are known to regulate lymphocyte activation and proliferation, but only a subset of genes was repeatedly differentially expressed at different time points during treatment.

Conclusions

Overall, the observed gene regulatory effects of GA on monocytes were modest and not stable over time. However, our study revealed several genes that are worthy of investigation in future studies on the molecular mechanisms of GA therapy.

Identification of shared genes and pathways: a comparative study of multiple sclerosis susceptibility, severity and response to interferon beta treatment

Recent genome-wide association studies (GWAS) have successfully identified several gene loci associated with multiple sclerosis (MS) susceptibility, severity or interferon-beta (IFN-ß) response. However, due to the nature of these studies, the functional relevance of these loci is not yet fully understood. We have utilized a systems biology based approach to explore the genetic interactomes of these MS related traits. We hypothesised that genes and pathways associated with the 3 MS related phenotypes might interact collectively to influence the heterogeneity and unpredictable clinical outcomes observed. Individual genetic interactomes for each trait were constructed and compared, followed by prioritization of common interactors based on their frequencies. Pathway enrichment analyses were performed to highlight shared functional pathways. Biologically relevant genes ABL1, GRB2, INPP5D, KIF1B, PIK3R1, PLCG1, PRKCD, SRC, TUBA1A and TUBA4A were identified as common to all 3 MS phenotypes. We observed that the highest number of first degree interactors were shared between MS susceptibility and MS severity (p = 1.34×10⁻⁷⁹) with UBC as the most prominent first degree interactor for this phenotype pair from the prioritisation analysis. As expected, pairwise comparisons showed that MS susceptibility and severity interactomes shared the highest number of pathways. Pathways from signalling molecules and interaction, and signal transduction categories were found to be highest shared pathways between 3 phenotypes. Finally, FYN was the most common first degree interactor in the MS drugs-gene network. By applying the systems biology based approach, additional significant information can be extracted from GWAS. Results of our interactome analyses are complementary to what is already known in the literature and also highlight some novel interactions which await further experimental validation. Overall, this study illustrates the potential of using a systems biology based approach in an attempt to unravel the biological significance of gene loci identified in large GWAS.

Interferon beta and glatiramer acetate therapy

Interferon beta and glatiramer acetate have been mainstays of treatment in relapsingremitting multiple sclerosis for two decades. Remarkable advances in our understanding of immune function and dysfunction as well as increasingly sophisticated clinical trial design have stemmed from efforts to better understand these drugs. In this chapter, we review the history of their development and elaborate on known and theorized mechanisms of action. We describe the pivotal clinical trials that have led to their widespread use. We evaluate the clinical use of the drugs including tolerability, side effects, and efficacy measures. Finally, we look to the future of interferon beta and glatiramer acetate in the context of an ever growing armamentarium of treatments for relapsing remitting multiple sclerosis.

Pharmacogenomic update on multiple sclerosis: a focus on actual and new therapeutic strategies

Multiple sclerosis (MS) is an inflammatory and demyelinating disease of central nervous system comprising several subtypes. Pharmacological treatment involves only few drugs. Among these, interferon beta (IFN-β) and glatiramer acetate were the most used. Although evidence supports the efficacy of these agents in treating MS symptoms, actual studies allowed to introduce new innovative drugs in clinical practice. Applying pharmacogenetic approach to MS, IFN-β and several other immune pathways were abundantly investigated. Numerous reports identified some promising therapy markers but only few markers have emerged as clinically useful. This may be partially due to differences in clinical and methodological criteria in the studies. Indeed, responder and non-responder definitions lack standardized clinical definition. The goal of this review is to treat advances in research on the pharmacogenetic markers of MS drugs and to highlight possible correlations between type of responses and genetic profile, with regard to clinical and methodological discrepancies in the studies.

Clinical utility of glatiramer acetate in the management of relapse frequency in multiple sclerosis

Glatiramer acetate (GA) represents one of the most common disease-modifying therapies for multiple sclerosis. GA is currently approved for patients at high risk of developing clinically definite multiple sclerosis (CDMS) after having experienced a well-defined first clinical episode (clinically isolated syndrome or CIS) and for patients with relapsing-remitting multiple sclerosis (RRMS). GA’s efficacy and effectiveness to reduce relapse frequency have been proved in placebo-controlled and observational studies. Comparative trials have also confirmed the lack of significant differences over other choices of treatment in the management of relapse frequency, and long-term studies have supported its effect at extended periods of time. Additionally, RRMS patients with suboptimal response to interferon β may benefit from reduced relapse rate after switching to GA, and those with clinically isolated syndrome may benefit from delayed conversion to CDMS. All these results, together with its proven long-term safety and positive effect on patients’ daily living, support the favorable risk-benefit of GA for multiple sclerosis treatment.

Contribution of endermology to improving indurations and panniculitis/lipoatrophy at glatiramer acetate injection site

INTRODUCTION

Endermology is a mechanical massage therapy that enables fat mobilization and body contouring. The authors' aim was to assess the effect of endermology on indurations and panniculitis/lipoatrophy associated with subcutaneous administration of glatiramer acetate in patients with multiple sclerosis (MS).

METHODS

This was a multicenter pilot experience carried out in patients with MS treated with glatiramer acetate who showed indurations and/ or panniculitis/lipoatrophy at the injection site. Patients underwent endermology and glatiramer acetate treatment according to clinical practice. The primary endpoint was the change in indurations and/or panniculitis/lipoatrophy after 12 endermology sessions.

RESULTS

Between April and July 2011, a total of 13 evaluable patients were included (mean age, 40.7±3.1 years; female, 100%; white, 100%; mean MS duration, 10.1±2.3 years; previous MS treatment, 46.2%; mean glatiramer acetate treatment duration, 27.3±9.5 months). Eleven patients (84.6%) showed local indurations (mean diameter, 3.4±0.5 cm; mean number, 9.0±1.0) and six patients (46.2%) areas of panniculitis/ lipoatrophy (mean number, 5.0±1.1). After 12 endermology sessions, patients with indurations reported having experienced a reduction in size (10 patients [90.9%]; mean diameter, 0.1±0.05 cm; P<0.001) and number of indurations (nine patients [81.8%]; mean number, 2.3±1.1; P<0.005). These indurations completely disappeared from arms, thighs, buttocks, and abdomen in six (75.0%), six (75.0%), two (50.0%), and three (42.9%) patients, respectively. Three of these patients (27.3%) recovered from all indurations. Although panniculitis/lipoatrophy did not completely disappear, all patients reported improvements. Most patients with indurations (63.6%) felt very satisfied and considered endermology very useful for reducing indurations. All patients with panniculitis/lipoatrophy were satisfied and considered to be endermology useful in improving it. In addition, endermology enabled glatiramer acetate tolerance to be improved in most patients (60.0%).

CONCLUSION

Endermology may contribute to improving indurations and panniculitis/ lipoatrophy at the site of subcutaneous injection of glatiramer acetate in patients with MS, enabling areas of injection to recover, and treatment tolerance to increase.

Comparative Long-Term Preclinical Safety Evaluation of Two Glatiramoid Compounds (Glatiramer Acetate, Copaxone®, and TV-5010, Protiramer) in Rats and Monkeys

Glatiramer acetate (GA), the active ingredient in Copaxone®, is a complex mixture of polypeptides used for the treatment of relapsing remitting multiple sclerosis. Glatiramoids are related mixtures that may differ in some characteristics of the prototype molecule. Our aim is to describe the long-term toxicity studies with protiramer (TV-5010), a new glatiramoid, in comparison with similar studies conducted with GA. The toxicity of twice-weekly subcutaneous injections of protiramer to Sprague-Dawley rats (twenty-six weeks) and cynomolgus monkeys (fifty-two weeks) was compared with similar studies done with daily subcutaneous injections of GA. Daily treatment with GA was safe and well tolerated, without systemic effects or death. Protiramer administration was not as well tolerated as GA and led to dose- and time-related mortalities, probably mediated through severe injection-site lesions both in rats and in monkeys. Bridging fibrosis in the liver and severe progressive nephropathy were seen in rats. A dose-related increase in eosinophils was observed in monkeys. The protiramer toxicity studies show that minor variations in the manufacturing of glatiramoids may lead to significant toxic effects. It is therefore essential that the safety of any new glatiramoid be studied in long-term preclinical studies before exposing humans.

Glatiramer acetate treatment increases stability of spinal synapses and down regulates MHC I during the course of EAE

The recent discovery that the major histocompatibility complex of class I (MHC I) expression has a role in the synaptic elimination process, represented an insight into understanding the cross talk between neurons. In the present study, the possibility that glatiramer acetate (GA) treatment influences the MHC class I expression and the synaptic plasticity process in the spinal cord during the course of EAE was investigated. C57BL/6J mice were induced to EAE and submitted to treatment either with a placebo solution or with GA (0.05mg/animal, subcutaneously, on a daily basis). All the animals were sacrificed at the peak disease (14 days after induction) or at the point of recovery of the clinical signs (21 days after induction). The spinal cords were removed and submitted to immunohistochemical examination, Western blotting and transmission electron microscopy analysis. The results showed that GA treatment was able to decrease synaptic loss during the course of EAE, which correlates with the downregulation of the MHC I complex. The present results reinforce the neuroprotective role of GA treatment, by reducing synaptic loss during the course of the disease. Such action may be associated with the recently described role of MHC I regulation during the synaptic plasticity process.

Fabrication principles and their contribution to the superior in vivo therapeutic efficacy of nano-liposomes remote loaded with glucocorticoids

We report here the design, development and performance of a novel formulation of liposome- encapsulated glucocorticoids (GCs). A highly efficient (>90%) and stable GC encapsulation was obtained based on a transmembrane calcium acetate gradient driving the active accumulation of an amphipathic weak acid GC pro-drug into the intraliposome aqueous compartment, where it forms a GC-calcium precipitate. We demonstrate fabrication principles that derive from the physicochemical properties of the GC and the liposomal lipids, which play a crucial role in GC release rate and kinetics. These principles allow fabrication of formulations that exhibit either a fast, second-order (t(1/2) ~1 h), or a slow, zero-order release rate (t(1/2) ~ 50 h) kinetics. A high therapeutic efficacy was found in murine models of experimental autoimmune encephalomyelitis (EAE) and hematological malignancies.

Glatiramer acetate for treatment of MS: regulatory B cells join the cast of players

Glatiramer acetate (GA, copolymer-1, Copaxone) is a Food and Drug Administration-approved drug for the treatment of relapsing-remitting multiple sclerosis (MS). However, its mechanism of action remains ill-defined. The available evidence indicates that GA induces antigen-presenting cells with anti-inflammatory properties and promotes the generation of immunoregulatory T cells that suppress pathogenic T cells. A new study by Kala et al. (2010) now shows that B lymphocytes, which are best known for their antibody-secreting properties, contribute to the beneficial effects of GA against experimental autoimmune encephalomyelitis (EAE), the animal model of MS. This commentary discusses these new findings in the context of the pathogenesis of MS and EAE, the emerging immunoregulatory role of B cells in autoimmunity, and the relevance of B cells as targets for immunotherapy in MS.

Glatiramer acetate-reactive T lymphocytes regulate oligodendrocyte progenitor cell number in vitro: role of IGF-2

Glatiramer acetate (GA) is an immunomodulator approved for therapy of relapsing-remitting multiple sclerosis (RRMS), but recent findings indicate that it may also have additional, neurotrophic effects. Here, we found that supernatants from human GA-reactive T lymphocytes potentiated oligodendrocyte numbers in rodent and human oligodendrocyte progenitor (OPC) cultures. Effects of Th2-polarized lines were stronger than Th1-polarized cells. Microarray and ELISA analyses revealed that neurotrophic factors induced in Th2- and Th1-polarized GA-reactive lines included IGF-2 and BMP-7 respectively, and functional studies confirmed IGF-2 as trophic for OPCs. Our results support the concept that GA therapy may result in supportive effects on oligodendrocytes in RRMS patients.

Glatiramer acetate: successful desensitization for treatment of multiple sclerosis

BACKGROUND

Glatiramer acetate is an immunomodulatory drug that is widely prescribed for the treatment of multiple sclerosis. It is frequently associated with local injection site reactions and generalized urticaria. It is also associated with immediate postinjection systemic reactions in approximately 10% of patients. To our knowledge, no desensitization protocols for glatiramer acetate have been published to date.

OBJECTIVES

To evaluate the safety and efficacy of glatiramer acetate desensitization in a series of patients with multiple sclerosis.

METHODS

Six patients with multiple sclerosis and glatiramer acetate-associated local or systemic reactions underwent a 4-hour outpatient desensitization procedure at Cleveland Clinic between 2003 and 2008. Beginning with 20 ng, we administered subcutaneous glatiramer acetate suspension in increasing dosages every 15 minutes. Patient outcomes were monitored by return clinic visit and telephone follow-up.

RESULTS

No episodes of anaphylaxis or serious adverse reactions occurred during or immediately after desensitization. One patient suspended therapy after 14 months due to persistent local injection site reactions. All other patients successfully continued glatiramer acetate therapy.

CONCLUSION

Glatiramer acetate offers significant benefit to patients with multiple sclerosis. Our experience suggests that patients who suspend its use owing to local or systemic reactions can be successfully and safely desensitized and can resume medication use. To our knowledge, this is the first report of successful desensitization to glatiramer acetate in patients with multiple sclerosis.

Risks vs benefits of glatiramer acetate: a changing perspective as new therapies emerge for multiple sclerosis

An understanding of the risks, benefits, and relative value of glatiramer acetate (GA) in multiple sclerosis (MS) has been evolving based on recently completed head-to-head studies: REGARD (REbif vs Glatiramer Acetate in Relapsing MS Disease); BEYOND (Betaseron Efficacy Yielding Outcomes of a New Dose); and BECOME (BEtaseron vs COpaxone in Multiple Sclerosis with Triple-Dose Gadolinium and 3-Tesla MRI Endpoints). Outcomes in the primary endpoints of these trials showed no significant differences between GA and high-dose beta-interferons (IFNβs). Results of the PreCISe (Early GA Treatment in Delaying Conversion to Clinically Definite Multiple Sclerosis [CDMS] in Subjects Presenting With a Clinically Isolated Syndrome [CIS]) trial led to the US Food and Drug Administration approval of GA in patients with a CIS. Furthermore, the ongoing follow-up study to the original pivotal GA trial, now extending beyond 15 years, continues to support the safety of GA. Currently, GA and IFNβs are no longer the only immunomodulators available for MS. Introduction of the monoclonal antibody, natalizumab (Tysabri^®; Biogen Idec, Inc., Cambridge, MA, USA) provides an alternative immunomodulator for MS and has changed the therapeutic landscape dramatically. However, the rare but serious cases of progressive multifocal leukoencephalopathy that have occurred with natalizumab have raised concerns among clinicians and patients about using this agent and some of the emerging agents. The potential risks and benefits of the emerging therapies (cladribine, alemtuzumab, rituximab, fingolimod, laquinimod, teriflunomide, and dimethyl fumarate) based on phase II/III trials, as well as their use for indications other than MS, will be presented. This review provides available data on GA, natalizumab, and the emerging agents to support new developments in our understanding of GA and how its long-standing role as a first-line therapy in MS will evolve within the increasingly complex MS therapeutic landscape.

Clinically validated approaches to the treatment of autoimmune diseases

IMPORTANCE OF THE FIELD

Autoimmune diseases are pathological conditions in which "self-tolerance" has been broken, and an immune response has been mounted against the body's own tissues. More than seventy autoimmune diseases have been described, some of which are systemic and others of which are organ-specific. Although many of these diseases are rare, the collective prevalence of autoimmune diseases in the United States alone is between 5 and 8%, and is increasing.

AREAS COVERED IN THIS REVIEW

Herein, we review the exciting advances made during the past decade (1999 - 2009) in the development of clinically-validated agents for the treatment of autoimmune disease. We focus on five of the most prevalent conditions: rheumatoid arthritis, psoriasis, multiple sclerosis, Crohn's disease, and systemic lupus erythematosus. The discussion is largely restricted to agents - both small molecules and macromolecules - that have advanced through randomized, controlled clinical trials.

WHAT THE READER WILL GAIN

An overview of the pathogenesis of each disease is provided, along with a description of the therapies. Results from pivotal clinical trials are tabulated for four of the disease areas. We also provide summaries of experiences with both failed clinical trials and side effects observed during the course of clinical investigations. We conclude the review with thoughts on current challenges in the field and the prospect for future innovations.

TAKE HOME MESSAGE

During the past decade, some of the largest advances in the treatment of autoimmune disease have arisen from highly potent and selective macromolecule-based therapies (e.g. antibodies, recombinant proteins and fusion proteins). Together, these clinical experiences have provided insight into the critical mechanisms in autoimmune pathogenesis, including inflammatory cytokine release, T-cell migration and co-stimulation, and B-cell function.

Improved muscle strength and mobility in the dy(2J)/dy(2J) mouse with merosin deficient congenital muscular dystrophy treated with Glatiramer acetate

The therapeutic effect of Glatiramer acetate, an immune modulating agent, was evaluated in the dy(2J)/dy(2J) mouse with merosin deficient congenital muscular dystrophy, which is a milder variant of the dy/dy mouse. The treated mice showed significant improvement in hind limb muscle strength measured by electronic grip strength meter and in motor performance quantified by video detection software. Glatiramer acetate treatment was associated with significantly increased expression of regeneration transcription factors MyoD and myogenin, and attenuation of the fibrosis markers vimentin and fibronectin. No effective treatment is currently available in congenital muscular dystrophy and Glatiramer acetate may present a new potential treatment for this disorder.

Glatiramer acetate immune system augmentation for peripheral nerve regeneration in rat crushed sciatic nerve model

BACKGROUND

Protective antiself response to nervous system injury has been reported to be mediated by a T-cell subpopulation that can recognize self-antigens. Immune cells have been shown to play a role in the regulation of motor neuron survival after a peripheral nerve injury. The objective of the present study was to evaluate the effects of immune system augmentation with use of the antigen glatiramer acetate, which is known to affect T-cell immunity, on peripheral nerve regeneration.

METHODS

Wild-type and nude-type (T-cell-deficient) rats underwent crush injury of the sciatic nerve. Three and six weeks after the injury, the sciatic nerve was examined, both functionally (on the basis of footprint analysis and the tibialis anterior muscle response and weight) and histologically (on the basis of axon count).

RESULTS

Significantly greater muscle responses were measured after three weeks in the group of wild-type rats that were treated with glatiramer acetate (control limb:injured limb ratio, 0.05 for the glatiramer acetate group [n = 9], compared with 0.51 for the saline solution group [n = 8]; p < 0.05). Higher axon counts were also found in this group (control limb:injured limb ratio, -0.07 for the glatiramer acetate group [n = 10], compared with 0.29 for the saline solution group [n = 8]; p < 0.05). The nude-type rats showed no response to the intervention after three weeks but showed a delayed response after six weeks. A second dose of glatiramer acetate, delivered forty-eight hours after the injury, did not result in an improved response as compared with the control groups.

CONCLUSIONS

We found that a single treatment with glatiramer acetate resulted in accelerated functional and histological recovery after sciatic nerve crush injury. The role of T-cell immunity in the mechanism of glatiramer acetate was suggested by the partial and late response found in the T-cell-deficient rats.

Restoring immune suppression in the multiple sclerosis brain

Multiple sclerosis is a very disabling inflammatory demyelinating disease of the brain of unknown etiology. Current therapies can reduce new lesion development and partially prevent clinical disease activity, but none can halt the progression, or cure the disease. We will review current therapeutic strategies, which are mostly discussed in literature in terms of their effective inhibition of T cells. However, we argue that many of these treatments also influence the myeloid compartment. Interestingly, recent evidence indicates that myelin phagocytosis by infiltrated macrophages and activated microglia is not just a hallmark of multiple sclerosis, but also a key determinant of lesion development and disease progression. We reason that severe side effects and/or insufficient effectiveness of current treatments necessitates the search for novel therapeutic targets, and postulate that these should aim at manipulation of the activation and phagocytic capacity of macrophages and microglia. We will discuss three candidate targets with high potential, namely the complement receptor 3, CD47-SIRPalpha interaction as well as CD200-CD200R interaction. Blocking the actions of complement receptor 3 could inhibit myelin phagocytosis, as well as migration of myeloid cells into the brain. CD47 and CD200 are known to inhibit macrophage/microglia activation through binding to their receptors SIRPalpha and CD200R, expressed on phagocytes. Triggering these receptors may thus dampen the inflammatory response. Our recent findings indicate that the CD200-CD200R interaction is the most specific and hence probably best-suited target to suppress excessive macrophage and microglia activation, and restore immune suppression in the brain of patients with multiple sclerosis.

Immune response to controlled release of immunomodulating peptides in a murine experimental autoimmune encephalomyelitis (EAE) model

The effects of controlled release on immune response to an immunomodulating peptide were evaluated in a murine experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). The peptide, Ac-PLP-BPI-NH(2)-2 (Ac-HSLGKWLGHPDKF-(AcpGAcpGAcp)(2)-ITDGEATDSG-NH(2); Ac = acetyl, Acp = epsilon aminocaproic acid) was designed to suppress T-cell activation in response to PLP(139-151), an antigenic peptide in MS. Poly-lactide-co-glycolide (PLGA) microparticles containing Ac-PLP-BPI-NH(2)-2 (8+/-4 microm, 1.4+/-0.2% (w/w)) were prepared by a powder-in oil-in water emulsion-solvent evaporation method, sterilized and administered subcutaneously (s.c.) to SJL/J (H-2(s)) mice in which EAE had been induced by immunization with PLP(139-151). Treatment groups received Ac-PLP-BPI-NH(2)-2: (i) in solution by repeated i.v. or s.c. injection, (ii) in solution co-administered with blank PLGA microparticles, (iii) in solution co-administered with Ac-PLP-BPI-NH(2)-2 loaded microparticles, and (iv) as Ac-PLP-BPI-NH(2)-2 loaded microparticles. Administration of Ac-PLP-BPI-NH(2)-2 as an s.c. solution produced clinical scores and maintenance of body weight comparable to i.v. solution, but with reduced overall survival, presumably due to anaphylaxis. Administration as s.c. microparticles provided a somewhat less effective reduction in symptoms but with no toxicity during treatment. Thus, the results suggest that s.c. administration of Ac-PLP-BPI-NH(2)-2 microparticles can provide pharmacological efficacy and reduction in dosing frequency without increased toxicity.

Benefits of glatiramer acetate in the treatment of relapsing-remitting multiple sclerosis

Relapsing-remitting multiple sclerosis is a chronic, progressive disorder marked by repeated exacerbations that lead to increases in neurological disability. Glatiramer acetate and the IFN-betas are recommended as first-line agents for relapsing-remitting multiple sclerosis owing to their potential to reduce frequency and severity of relapses, decrease development of new brain lesions and delay permanent disability. After three decades of study, the preponderance of the evidence suggests that the efficacy of glatiramer acetate is similar to the IFN-betas and new data collected in more naturalistic settings suggest that it may provide improved quality of life, increased productivity and cost-effectiveness. This article will review this evidence including data from very recent head-to-head clinical trials and pharmacoeconomic analyses of cost-effectiveness.

Therapeutic potential of IL-27 in multiple sclerosis?

BACKGROUND

Multiple sclerosis (MS) is a debilitating neurological disease, characterized by inflammatory demyelination and axonal degeneration in the CNS. Currently approved therapies are partially effective, however safer and more effective treatments are needed.

OBJECTIVE/METHODS

To assess the therapeutic potential of the heterodimeric cytokine, IL-27 in MS, based on the current literature.

RESULTS/CONCLUSIONS

IL-27 exerts profound anti-inflammatory effects in several infectious and experimental autoimmune models. In particular, suppressive effects on helper T cells, which are implicated in the pathogenesis of MS, suggest that IL-27 may be therapeutically relevant in MS. However, while exciting discoveries have been made, further work is required particularly in human health and disease, to understand the diverse roles of IL-27 and its therapeutic potential.

Development of laquinimod for relapsing–remitting multiple sclerosis

Laquinimod, a quinoline-3-carboxamide derivative, is a new, once-daily oral immunomodulatory therapy in development for the treatment of relapsing–remitting multiple sclerosis (MS). It has demonstrated efficacy in both acute and chronic experimental allergic encephalitis and in animal models of other inflammatory autoimmune diseases. It appears to act, in part, by shifting the immune response from a Th1 to a Th2 response and does not act through nonspecific immunosuppression. In Phase II studies in relapsing forms of MS, laquinimod brought about a 60% decrease in the cumulative number of gadolinium-enhancing lesions and a 33% decrease in relapse rates. In Phase II studies it was safe and well-tolerated. The most common laboratory abnormalities were a transient rise in alanine aminotransferase and C-reactive protein that returned to normal values despite continued therapy. There was no evidence of a proinflammatory effect. Phase III clinical trials for registration are in progress. Laquinimod may find use as a first-line agent in the treatment of relapsing forms of MS.

The results of two multicenter, open-label studies assessing efficacy, tolerability and safety of protiramer, a high molecular weight synthetic copolymeric mixture, in patients with relapsing–remitting multiple sclerosis

Objective

Two pilot studies were conducted to evaluate safety, tolerability, and efficacy of two doses of Protiramer (TV-5010) in patients with relapsing–remitting multiple sclerosis.

Background

Both glatiramer acetate and TV-5010 are synthetic copolymers comprised the same four amino acids in a defined molar ratio. TV-5010 has higher average molecular weight than Glatiramer acetate and might be hypothesized that glatiramoids with higher molecular weight might be more immunoreactive than lower molecular weight peptides, thus increasing therapeutic potential and allowing for less frequent dosing.

Methods

In the two separate studies, after a 10 week pretreatment period, TV-5010 was given subcutaneously once weekly at 15 mg and 30 mg for 36 weeks. The primary end point was a reduction in the number of magnetic resonance imaging active lesions (i.e., T1-weigthed gadolinium-enhancing and new T2-weighted lesions) between the pretreatment period and the end of study.

Results

Both TV-5010 doses were generally well tolerated. The treatment with TV-5010 at a dose of 15 mg/wk did not show any significant effect. In contrast, in patients treated with at a dose of 30 mg/wk, a significant reduction in the mean number of gadolinium-enhancing (−58.8%; P = 0.0013) and new T2-W (−50%; P = 0.0002) lesions was observed. However, a large decrease in the mean number of both gadolinium-enhancing (−55%) and new T2-W (−40%) lesions during the pretreatment period made difficult the interpretation of the efficacy assessments.

Conclusions

Further studies are needed to confirm these preliminary data on safety and efficacy of TV-5010 at a weekly dose of 30 mg.