Disruption of the interaction of T cells with antigen-presenting cells by the active leflunomide metabolite teriflunomide: involvement of impaired integrin activation and immunologic synapse formation

Distinct disease-modifying therapies are associated with different blood immune cell profiles in people with relapsing-remitting multiple sclerosis

Disease modifying therapies (DMTs) used for treating people with relapsing-remitting multiple sclerosis (pwRRMS) target the immune system by different mechanisms of action. However, there is a lack of a comprehensive assessment of their effects on the immune system in comparison to treatment-naïve pwRRMS. Herein, we evaluated the numbers of circulating B cells, CD4+ and CD8+ T cells, regulatory T cells (Tregs), natural killer (NK) cells and NKT cells, and their subsets, in pwRRMS who were treatment-naïve or treated with different DMTs. Compared to treatment-naïve pwRRMS, common and divergent effects on immune system cells were observed on pwRRMS treated with different DMTs, with no consistent pattern across all therapies in any of the cell populations analysed. PwRRMS treated with fingolimod, dimethyl fumarate (DMF), or alemtuzumab have reduced numbers of CD4+ and CD8+ T cells, as well as Treg subsets, with fingolimod causing the most pronounced decrease in T cell subsets. In contrast, teriflunomide and interferon (IFN) β have minimal impact on T cells, and natalizumab marginally increases the number of memory T cells in the blood. The effect of DMTs on the B cell, NKT and NK cell subsets is highly variable with alemtuzumab inducing a strong increase in the number of the most immature NK cells and its subsets. This study comprehensively evaluates the magnitude of the effect of different DMTs on blood immune cells providing a better understanding of therapy outcome. Furthermore, the lack of a discernible pattern in the effects of DMTs on blood immune cells suggests that multiple immune cells can independently modulate the disease.

Advances in Multiple Sclerosis Neurotherapeutics, Neuroprotection, and Risk Mitigation Strategies

The treatment of patients with relapsing multiple sclerosis (MS) has advanced tremendously over the past few decades. More efficacious therapies have been approved, which can significantly reduce the inflammatory process of relapsing MS. Neuroprotection by controlling this pathophysiology is important given our current limitations to control progressive MS and induce neurorepair. Here, the authors discuss the current landscape of neurotherapeutics for relapsing MS focusing on newer disease-modifying treatments and their use. Risk mitigation of these medications can greatly improve their safety and improve their benefit-risk balance. The authors discuss treatment strategies for risk mitigation including treatment discontinuation and de-escalation.

Safety and Monitoring of the Treatment with Disease-Modifying Therapies (DMTs) for Multiple Sclerosis (MS)

BACKGROUND

Disease-Modifying Therapies (DMTs) for Multiple Sclerosis (MS) are widely used given their proven efficacy in the relapsing form of the disease, while recently, Siponimod and Ocrelizumab have been approved for the progressive forms of the disease. Currently, 22 diseasemodifying drugs are approved by the FDA, while in 2012, only nine were present in the market. From March 2019 until August 2020, six new drugs were approved. This rapid development of new DMTs highlighted the need to update our knowledge about their short and long-term safety.

OBJECTIVE

This review summarizes the available safety data for all the Disease-Modifying Therapies for Multiple Sclerosis and presents the monitoring plan before and during the treatment.

METHODS

A literature search was conducted using PUBMED and COCHRANE databases. Key journals and abstracts from major annual meetings of Neurology, references of relevant reviews, and relative articles were also manually searched. We prioritized systematic reviews, large randomized controlled trials (RCTs), prospective cohort studies, and other observational studies. Special attention was paid to guidelines and papers focusing on the safety and monitoring of DMTs.

CONCLUSION

Data for oral (Sphingosine 1-phosphate (S1P) receptor modulators, Fumarates, Teriflunomide, Cladribine), injectables (Interferons, Glatiramer acetate, Ofatumumab), and infusion therapies (Natalizumab, Ocrelizumab, Alemtuzumab) are presented.

Multiple Sclerosis: Therapeutic Strategies on the Horizon

Multiple sclerosis (MS) is a chronic disease affecting the brain and the spinal cord. It is a chronic inflammatory demyelinating disease of the central nervous system. It is the leading cause of non-traumatic disability in young adults. The clinical course of the disease is quite variable, ranging from stable chronic disease to rapidly evolving debilitating disease. The pathogenesis of MS is not fully understood. Still, there has been a rapid shift in understanding the immune pathology of MS away from pure T cell-mediated disease to B cells and microglia/astrocytes having a vital role in the pathogenesis of MS. This has helped in the emergence of new therapies for management. Effective treatment of MS requires a multidisciplinary approach to manage acute attacks, prevent relapses and disease progression and treat the disabling symptoms associated with the disease. In this review, we discuss the pathogenesis of MS, management of acute relapses, disease-modifying therapies in MS, new drugs and drugs currently in trial for MS and the symptomatic treatment of MS.  All language search was conducted on Google Scholar, PubMed, MEDLINE, and Embase till February 2022. The following search strings and medical subheadings (MeSH) were used: "Multiple Sclerosis", "Pathogenesis of MS", and "Disease-modifying therapies in MS". We explored literature on the pathogenic mechanisms behind MS, management of acute relapses, disease-modifying therapies in MS and symptomatic management.

Adverse Effects of Immunosuppression: Infections

Immunosuppressive therapies are currently indicated for a wide range of diseases. As new agents emerge and indications evolve the landscape grows increasingly complex. Therapies can target pathologic immune system over-activation in rheumatologic or autoimmune disease, or conditioning and graft versus host disease (GVHD) prophylactic regimens may eliminate or inhibit host immune function to improve graft survival and risk of complication in solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT). With immunosuppressive therapy, infections occur. Complex disease states, host factors, and concomitant therapies contribute to a "net state" of immunosuppression that must be considered and may confound perceived increased infection risks in patients receiving treatment.

Teriflunomide Treatment of Multiple Sclerosis Selectively Modulates CD8 Memory T Cells

Background and Objectives

Inhibition of de novo pyrimidine synthesis in proliferating T and B lymphocytes by teriflunomide, a pharmacological inhibitor of dihydroorotate dehydrogenase (DHODH), has been shown to be an effective therapy to treat patients with MS in placebo-controlled phase 3 trials. Nevertheless, the underlying mechanism contributing to the efficacy of DHODH inhibition has been only partially elucidated. Here, we aimed to determine the impact of teriflunomide on the immune compartment in a longitudinal high-dimensional follow-up of patients with relapse-remitting MS (RRMS) treated with teriflunomide.

Methods

High-dimensional spectral flow cytometry was used to analyze the phenotype and the function of innate and adaptive immune system of patients with RRMS before and 12 months after teriflunomide treatment. In addition, we assessed the impact of teriflunomide on the migration of memory CD8 T cells in patients with RRMS, and we defined patient immune metabolic profiles.

Results

We found that 12 months of treatment with teriflunomide in patients with RRMS does not affect the B cell or CD4 T cell compartments, including regulatory TREG follicular helper TFH cell and helper TH cell subsets. In contrast, we observed a specific impact of teriflunomide on the CD8 T cell compartment, which was characterized by decreased homeostatic proliferation and reduced production of TNFα and IFNγ. Furthermore, we showed that DHODH inhibition also had a negative impact on the migratory velocity of memory CD8 T cells in patients with RRMS. Finally, we showed that the susceptibility of memory CD8 T cells to DHODH inhibition was not related to impaired metabolism.

Discussion

Overall, these findings demonstrate that the clinical efficacy of teriflunomide results partially in the specific susceptibility of memory CD8 T cells to DHODH inhibition in patients with RRMS and strengthens active roles for these T cells in the pathophysiological process of MS.

Update on treatment in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. In recent years, many disease-modifying therapies (DMT) have been approved for MS treatment. For this reason, a profound knowledge of the characteristics and indications of the available compounds is required to tailor the therapeutic strategy to the individual patient characteristics. This should include the mechanism of action and pharmacokinetic of the drug, the safety and efficacy profile provided by clinical trials, as well as the understanding of possible side effects. Moreover, the evolving knowledge of the disease is paving the way to new and innovative therapeutic approaches, as well as the development of new biomarkers to monitor the therapeutic response and to guide the clinician's therapeutic choices. In this review we provide a comprehensive overview on currently approved therapies in MS and the emerging evidence-based strategies to adopt for initiating, monitoring, and eventually adapting a therapeutic regimen with DMT.

Immunology of COVID-19 and disease-modifying therapies: The good, the bad and the unknown

Objective

The outbreak of the SARS‐CoV‐2 pandemic, caused by a previously unknown infectious agent, posed unprecedented challenges to healthcare systems and unmasked their vulnerability and limitations worldwide. Patients with long‐term immunomodulatory/suppressive therapies, as well as their physicians, were and are concerned about balancing the risk of infection and effects of disease‐modifying therapy. Over the last few months, knowledge regarding SARS‐CoV‐2 has been growing tremendously, and the first experiences of infections in patients with multiple sclerosis (MS) have been reported.

Methods

This review summarizes the currently still limited knowledge about SARS‐CoV‐2 immunology and the commonly agreed modes of action of approved drugs in immune‐mediated diseases of the central nervous system (MS and neuromyelitis optica spectrum disorder). Specifically, we discuss whether immunosuppressive/immunomodulatory drugs may increase the risk of SARS‐CoV‐2 infection and, conversely, may decrease the severity of a COVID‐19 disease course.

Results

At present, it can be recommended in general that none of those therapies with a definite indication needs to be stopped per se. A possibly increased risk of infection for most medications is accompanied by the possibility to reduce the severity of COVID‐19.

Conclusions

Despite the knowledge gain over the last few months, current evidence remains limited, and, thus, further clinical vigilance and systematic documentation is essential.

An Overview of Therapeutic Options in Relapsing-remitting Multiple Sclerosis

Multiple sclerosis (MS) is a chronic disorder of the central nervous system (CNS). MS affects 2.1 million individuals every year and is also considered a major cause of economic health burden around the world. Genetics and environmental factors both play a role in the pathogenesis of MS by activating the immune response and causing inflammation. Patients with MS can have various clinical courses, but the most common pattern seen is relapsing-remitting multiple sclerosis (RRMS). Multiple therapeutic options have been studied to prevent RRMS patients from frequent relapses. The oldest and most frequently used medication for MS is interferon beta, either used alone or as add-on therapy with other drugs. Newer treatment options that have been recently approved to control MS symptoms and suppress the inflammation are glatiramer acetate and siponimod. Infusion therapies consisting of monoclonal antibodies and immunosuppressive drugs have also been studied in the recent past. Some trials have been conducted on the use of stem cells for RRMS patients. We have briefly discussed all treatment options and the response of RRMS patients in multiple trials.

Modulating acute neuroinflammation in intracerebral hemorrhage: the potential promise of currently approved medications for multiple sclerosis

The secondary inflammatory injury following intracerebral hemorrhage (ICH) results in increased morbidity and mortality. White blood cells have been implicated as critical mediators of this inflammatory injury. Currently, no medications have been clinically proven to ameliorate or beneficially modulate inflammation, or to improve outcomes by any mechanism, following ICH. However, other neuroinflammatory conditions, such as multiple sclerosis, have approved pharmacologic therapies that modulate the inflammatory response and minimize the damage caused by inflammatory cells. Thus, there is substantial interest in existing therapies for neuroinflammation and their potential applicability to other acute neurological diseases such as ICH. In this review, we examined the mechanism of action of twelve currently approved medications for multiple sclerosis: alemtuzumab, daclizumab, dimethyl fumarate, fingolimod, glatiramer acetate, interferon beta-1a, interferon beta-1b, mitoxantrone, natalizumab, ocrelizumab, rituximab, teriflunomide. We analyzed the existing literature pertaining to the effects of these medications on various leukocytes and also with emphasis on mechanisms of action during the acute period following initiation of therapy. As a result, we provide a valuable summary of the current body of knowledge regarding these therapies and evidence that supports or refutes their likely promise for treating neuroinflammation following ICH.

Teriflunomide induces a tolerogenic bias in blood immune cells of MS patients

Objectives

Teriflunomide, a disease‐modifying treatment approved for multiple sclerosis (MS), inhibits reversibly dihydroorotate dehydrogenase, an enzyme involved in de novo pyrimidine biosynthesis and down‐regulates proliferation of activated lymphocytes. We aimed to study the impact of this drug in the lymphocyte profiles of MS patients.

Methods

Fifty‐five patients with relapsing‐remitting MS who initiated teriflunomide treatment were included in the study. We studied peripheral blood mononuclear cells obtained before and 6 months after treatment initiation and explored effector, memory, and regulatory cells by flow cytometry. Wilcoxon matched pair tests were used to assess differences between basal and 6 months after treatment results. P‐values were corrected with Bonferroni test.

Results

When explored T and B cell subsets, we observed a decrease in the percentages of terminally differentiated CD4+ T cells (P = 0.001) and plasmablasts (P < 0.0001) after 6 months of treatment. These results were confirmed with the total cell number. When studied immunomodulatory cells, we observed a clear increase of monocytes expressing programmed death‐ligand 1 (PD‐L1) (P = 0.005), which correlated negatively with all effector CD8+ T cell subsets. We also observed an increase in the percentage of CD8+ T cells (P = 0.028) and monocytes (P = 0.04) producing IL‐10.

Conclusions

Teriflunomide induces a specific reduction in effector T and B cells that have shown to play a role in MS course and an increase in immunomodulatory cells. Particularly, this drug induces the expression of PD‐L1, a molecule involved in tolerance to autoantigens, which can contribute to inhibit the abnormal immune response taking place in MS.

Teriflunomide Modulates Vascular Permeability and Microglial Activation after Experimental Traumatic Brain Injury

Despite intensive research and clinical trials with numerous therapeutic treatments, traumatic brain injury (TBI) is a serious public health problem in the United States. There is no effective FDA-approved treatment to reduce morbidity and mortality associated with TBI. Inflammation plays a pivotal role in the pathogenesis of TBI. We looked to re-purpose existing drugs that reduce immune activation without broad immunosuppression. Teriflunomide, an FDA-approved drug, has been shown to modulate immunological responses outside of its ability to inhibit pyrimidine synthesis in rapidly proliferating cells. In this study, we tested the efficacy of teriflunomide to treat two different injury intensities in rat models of TBI. Our results show that teriflunomide restores blood-brain barrier integrity, decreases inflammation, and increases neurogenesis in the subgranular zone of the hippocampus. While we were unable to detect neurocognitive effects of treatment on memory and special learning abilities after treatment, a 2-week treatment following injury was sufficient to reduce neuroinflammation up to 120 days later.

Teriflunomide attenuates neuroinflammation-related neural damage in mice carrying human PLP1 mutations

BACKGROUND

Genetically caused neurological disorders of the central nervous system (CNS) are mostly characterized by poor or even fatal clinical outcome and few or no causative treatments are available. Often, these disorders are associated with low-grade, disease-promoting inflammation, another feature shared by progressive forms of multiple sclerosis (PMS). We previously generated two mouse lines carrying distinct mutations in the oligodendrocytic PLP1 gene that have initially been identified in patients diagnosed with MS. These mutations cause a loss of PLP function leading to a histopathological and clinical phenotype common to both PMS and genetic CNS disorders, like hereditary spastic paraplegias. Importantly, neuroinflammation promotes disease progression in these models, suggesting that pharmacological modulation of inflammation might ameliorate disease outcome.

METHODS

We applied teriflunomide, an approved medication for relapsing-remitting MS targeting activated T-lymphocytes, in the drinking water (10 mg/kg body weight/day). Experimental long-term treatment of PLP mutant mice was non-invasively monitored by longitudinal optical coherence tomography and by rotarod analysis. Immunomodulatory effects were subsequently analyzed by flow cytometry and immunohistochemistry and treatment effects regarding neural damage, and neurodegeneration were assessed by histology and immunohistochemistry.

RESULTS

Preventive treatment with teriflunomide attenuated the increase in number of CD8+ cytotoxic effector T cells and fostered the proliferation of CD8+ CD122+ PD-1+ regulatory T cells in the CNS. This led to an amelioration of axonopathic features and neuron loss in the retinotectal system, also reflected by reduced thinning of the innermost retinal composite layer in longitudinal studies and ameliorated clinical outcome upon preventive long-term treatment. Treatment of immune-incompetent PLP mutants did not provide evidence for a direct, neuroprotective effect of the medication. When treatment was terminated, no rebound of neuroinflammation occurred and histopathological improvement was preserved for at least 75 days without treatment. After disease onset, teriflunomide halted ongoing axonal perturbation and enabled a recovery of dendritic arborization by surviving ganglion cells. However, neither neuron loss nor clinical features were ameliorated, likely due to already advanced neurodegeneration before treatment onset.

CONCLUSIONS

We identify teriflunomide as a possible medication not only for PMS but also for inflammation-related genetic diseases of the nervous system for which causal treatment options are presently lacking.

Synthesis of trifluoromethylated 2H-azirines through Togni reagent-mediated trifluoromethylation followed by PhIO-mediated azirination

The reaction of enamine compounds with the Togni reagent in the presence of CuI afforded β-trifluoromethylated enamine intermediates, which were converted directly to biologically interesting trifluoromethylated 2H-azirines by an iodosobenzene (PhIO)-mediated intramolecular azirination in a one-pot process.

Leflunomide: A promising drug with good antitumor potential

Leflunomide, an inhibitor of dihydroorotase dehydrogenase and thereby pyrimidine synthesis, was approved for treatment of rheumatoid arthritis in 1998. During the following years, leflunomide was used in various preclinical studies as a potential cancer treatment; at the same time, more mechanisms underlying the anticancer effect of leflunomide were identified. Thus, leflunomide has been identified as a potent anticancer drug. This article summarizes the mechanisms as well as results of leflunomide in the evolving field of cancer therapy.

Potential immunotherapies for sarcoidosis

INTRODUCTION

Sarcoidosis is a chronic granulomatous inflammatory disease that commonly causes lung disease, but can affect other vital organs and tissues. The cause of sarcoidosis is unknown, and current therapies are commonly limited by lack of efficacy, adverse side effects, and excessive cost.

AREAS COVERED

The manuscript will provide a review of current concepts relating to the pathogenesis of sarcoidosis, and how these disease mechanisms may be leveraged to develop more effective treatments for sarcoidosis. It provides only a brief summary of currently accepted therapy, while focusing more extensively on potential novel therapies.

EXPERT OPINION

Current sarcoidosis therapeutic agents primarily target the M1 or pro-inflammatory pathways. Agents that prevent M2 polarization, a regulatory phenotype favoring fibrosis, are attractive treatment alternatives that could potentially prevent fibrosis and associated life threatening complications. Effective treatment of sarcoidosis potentially requires simultaneous modulation both M1/M2 polarization instead of suppressing one pathway over the other to restore immune competent and inactive (M0) macrophages.

The sequence of disease-modifying therapies in relapsing multiple sclerosis: safety and immunologic considerations

The treatment landscape for relapsing forms of multiple sclerosis (RMS) has expanded considerably over the last 10 years with the approval of multiple new disease-modifying therapies (DMTs), and others in late-stage clinical development. All DMTs for RMS are believed to reduce central nervous system immune-mediated inflammatory processes, which translate into demonstrable improvement in clinical and radiologic outcomes. However, some DMTs are associated with long-lasting effects on the immune system and/or serious adverse events, both of which may complicate the use of subsequent therapies. When customizing a treatment program, a benefit–risk assessment must consider multiple factors, including the efficacy of the DMT to reduce disease activity, the short- and long-term safety and immunologic profiles of each DMT, the criteria used to define switching treatment, and the risk tolerance of each patient. A comprehensive benefit–risk assessment can only be achieved by evaluating the immunologic, safety, and efficacy data for DMTs in the controlled clinical trial environment and the postmarketing clinical practice setting. This review is intended to help neurologists make informed decisions when treating RMS by summarizing the known data for each DMT and raising awareness of the multiple considerations involved in treating people with RMS throughout the entire course of their disease.

Effector and regulatory B cells in Multiple Sclerosis

The role of B cells in the pathogenesis of Multiple Sclerosis (MS), an autoimmune neurodegenerative disease, is becoming eminent in recent years, but the specific contribution of the distinct B cell subsets remains to be elucidated. Several B cell subsets have shown regulatory, anti-inflammatory capacities in response to stimuli in vitro, as well as in the animal model of MS: Experimental Autoimmune Encephalomyelitis (EAE). However, the functional role of the B regulatory cells (Bregs) in vivo and specifically in the human disease is yet to be clarified. In the present review, we have summarized the updated information on the roles of effector and regulatory B cells in MS and the immune-modulatory effects of MS therapeutic agents on their phenotype and function.

What's new about oral treatments in Multiple Sclerosis? Immunogenetics still under question

Multiple Sclerosis (MS) is a chronic pathology affecting the Central Nervous System characterized by inflammatory processes that lead to demyelination and neurodegeneration. In MS treatment, disease modifying therapies (DMTs) are essential to reduce disease progression by suppressing the inflammatory response responsible for promoting lesion formation. Recently, in addition to the classical injectable DMTs like Interferons and Glatiramer acetate, new orally administered drugs have been approved for MS therapy: dimethyl fumarate, teriflunomide and fingolimod. These drugs act with different mechanisms on the immune system, in order to suppress the harmful inflammatory process. An additional layer of complexity is introduced by the influence of polymorphic gene variants in the Human Leukocyte Antigen region on the risk of developing MS and its progression. To date, pharmacogenomic studies have mainly focused on the patient's response following admission of injectable drugs. Therefore, greater consideration must be made to pharmacogenomics with a view to developing more effective and personalized therapies. This review aims to shed light on the mechanism of action of the new oral drugs dimethyl fumarate, teriflunomide and fingolimod, taking into account both the importance of immunogenetics in drug response and pharmacogenomic studies.

Mechanism of action of three newly registered drugs for multiple sclerosis treatment

Multiple sclerosis (MS) is a disease of suspected autoimmune origin leading to neurodegeneration. The disease pathomechanism is considered to be primarily based on neuroinflammation directed against myelin antigens caused by autoreactive T cells. MS etiology remains still unknown, which makes it difficult to create an efficient therapy, therefore, MS treatment targets mechanisms involved in disease pathology. In this review, we present the mechanism of action of three newly registered drugs for MS. Dimethyl fumarate (DMF) is an agent presenting a broad spectrum of action. Its main activity is based on activating the nuclear factor E2 dependent pathway leading to antioxidant enzyme synthesis. DMF in general suppresses the pro-inflammatory immune activity and exerts a neuroprotective action. Teriflunomide is a more focused drug, acting as an inhibitor of pyrimidines synthesis, important for rapidly dividing cells such as activated lymphocytes. Similarly, alemtuzumab, an anti-CD52 antibody, causes depletion of mainly lymphocytes. Since in MS pathology, T and B cells are involved, this mode of action is promising.

From Leflunomide to Teriflunomide: Drug Development and Immunosuppressive Oral Drugs in the Treatment of Multiple Sclerosis

BACKGROUND

Immunosuppressive drugs have been used in the treatment of multiple sclerosis (MS) for a long time. Today, orally available second generation immunosuppressive agents have been approved or are filed for licensing as MS therapeutics. Due to semi-selective targeting of cellular processes, these second-generation immunosuppressive compounds might rather be immunomodulatory. For example, Teriflunomide inhibits the de novo pyrimidine synthesis and thus only targets rapidly proliferating cells, including lymphocytes. It is used as first line disease modifying therapy (DMT) in relapsing-remitting MS (RRMS).

METHODS

Review of online content related to oral immunosuppressants in MS with an emphasis on Teriflunomide.

RESULTS

Teriflunomide and Cladribine are second-generation immunosuppressants that are efficient in the treatment of MS patients. For Teriflunomide, a daily dose of 14 mg reduces the annualized relapse rate (ARR) by more than 30% and disability progression by 30% compared to placebo. Cladribine reduces the ARR by about 50% compared to placebo but has not yet been licensed due to unresolved safety concerns. We also discuss the significance of older immunosuppressive compounds including Azathioprine, Mycophenolate mofetile, and Cyclophosphamide in current MS therapy.

CONCLUSION

Teriflunomide has shown a favorable safety and efficacy profile in RRMS and is a therapeutic option for a distinct group of adult patients with RRMS.

NF-κB Pathways in the Pathogenesis of Multiple Sclerosis and the Therapeutic Implications

Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways are involved in cell immune responses, apoptosis and infections. In multiple sclerosis (MS), NF-κB pathways are changed, leading to increased levels of NF-κB activation in cells. This may indicate a key role for NF-κB in MS pathogenesis. NF-κB signaling is complex, with many elements involved in its activation and regulation. Interestingly, current MS treatments are found to be directly or indirectly linked to NF-κB pathways and act to adjust the innate and adaptive immune system in patients. In this review, we will first focus on the intricacies of NF-κB signaling, including the activating pathways and regulatory elements. Next, we will theorize about the role of NF-κB in MS pathogenesis, based on current research findings, and discuss some of the associated therapeutic implications. Lastly, we will review four new MS treatments which interrupt NF-κB pathways—fingolimod, teriflunomide, dimethyl fumarate (DMF) and laquinimod (LAQ)—and explain their mechanisms, and the possible strategy for MS treatments in the future.

Xianfanghuomingyin, a Chinese Compound Medicine, Modulates the Proliferation and Differentiation of T Lymphocyte in a Collagen-Induced Arthritis Mouse Model

In traditional Chinese medicine (TCM), xianfanghuomingyin (XFHM) is used to treat autoimmune diseases, including rheumatoid arthritis (RA). Here, we studied the mechanisms underlying its treatment effects, especially its anti-inflammatory effects in a collagen-induced arthritis (CIA) mouse model. We found that cartilage destruction and pannus formation were alleviated by treatment with XFHM. The abnormal differentiation of Th1 and Th17 cells was downregulated significantly by XFHM, and Th2 and Treg cells were upregulated. Moreover, the expression levels of specific cytokines and transcription factors related to Th1 cells (interferon γ [IFNγ], T-bet) and Th17 cells (interleukin- [IL-] 17) and the nuclear receptor retinoic acid receptor-related orphan receptor-gamma (RORγ) were downregulated. Serum IL-4 and GATA-3, which contribute to Th2 cells differentiation, increased significantly after XFHM administration. These results indicate that XFHM can restore the balance of T lymphocytes and reestablish the immunological tolerance to inhibit autoinflammatory disorder of RA. Taken together, XFHM can be used as a complementary or alternative traditional medicine to treat RA.

Further understanding of the immunopathology of multiple sclerosis: impact on future treatments

INTRODUCTION

The understanding of the immunopathogenesis of multiple sclerosis (MS) has expanded with more research into T-cell subtypes, cytokine contributors, B-cell participation, mitochondrial dysfunction, and more. Treatment options have rapidly expanded with three relatively recent oral therapy alternatives entering the arena.

AREAS COVERED

In the following review, we discuss current mechanisms of immune dysregulation in MS, how they relate to current treatments, and the impact these findings will have on the future of therapy. Expert commentary: The efficacy of these medications and understanding their mechanisms of actions validates the immunopathogenic mechanisms thought to underlie MS. Further research has exposed new targets, while new promising therapies have shed light on new aspects into the pathophysiology of MS.

Teriflunomide for multiple sclerosis

BACKGROUND

This is an update of the Cochrane review "Teriflunomide for multiple sclerosis" (first published in The Cochrane Library 2012, Issue 12).Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system. It is clinically characterized by recurrent relapses or progression, or both, often leading to severe neurological disability and a serious decline in quality of life. Disease-modifying therapies (DMTs) for MS aim to prevent occurrence of relapses and disability progression. Teriflunomide is a pyrimidine synthesis inhibitor approved by both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) as a DMT for adults with relapsing-remitting MS (RRMS).

OBJECTIVES

To assess the absolute and comparative effectiveness and safety of teriflunomide as monotherapy or combination therapy versus placebo or other disease-modifying drugs (DMDs) (interferon beta (IFNβ), glatiramer acetate, natalizumab, mitoxantrone, fingolimod, dimethyl fumarate, alemtuzumab) for modifying the disease course in people with MS.

SEARCH METHODS

We searched the Cochrane Multiple Sclerosis and Rare Diseases of the CNS Group Specialised Trials Register (30 September 2015). We checked reference lists of published reviews and retrieved articles and searched reports (2004 to September 2015) from the MS societies in Europe and America. We also communicated with investigators participating in trials of teriflunomide and the pharmaceutical company, Sanofi-Aventis.

SELECTION CRITERIA

We included randomized, controlled, parallel-group clinical trials with a length of follow-up of one year or greater evaluating teriflunomide, as monotherapy or combination therapy, versus placebo or other approved DMDs for people with MS without restrictions regarding dose, administration frequency and duration of treatment.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures of Cochrane. Two review authors independently assessed trial quality and extracted data. Disagreements were discussed and resolved by consensus among the review authors. We contacted the principal investigators of included studies for additional data or confirmation of data.

MAIN RESULTS

Five studies involving 3231 people evaluated the efficacy and safety of teriflunomide 7 mg and 14 mg, alone or with add-on IFNβ, versus placebo or IFNβ-1a for adults with relapsing forms of MS and an entry Expanded Disability Status Scale score of less than 5.5.Overall, there were obvious clinical heterogeneities due to diversities in study designs or interventions and methodological heterogeneities across studies. All studies had a high risk of detection bias for relapse assessment and a high risk of bias due to conflicts of interest. Among them, three studies additionally had a high risk of attrition bias due to a high dropout rate and two studies had an unclear risk of attrition bias. The studies of combination therapy with IFNβ (650 participants) and the study with IFNβ-1a as controls (324 participants) also had a high risk for performance bias and a lack of power due to the limited sample.Two studies evaluated the benefit and the safety of teriflunomide as monotherapy versus placebo over a period of one year (1169 participants) or two years (1088 participants). A meta-analysis was not conducted. Compared to placebo, administration of teriflunomide at a dose of 7 mg/day or 14 mg/day as monotherapy reduced the number of participants with at least one relapse over one year (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.59 to 0.87, P value = 0.001 with 7 mg/day and RR 0.60, 95% CI 0.48 to 0.75, P value < 0.00001 with 14 mg/day) or two years (RR 0.85, 95% CI 0.74 to 0.98, P value = 0.03 with 7 mg/day and RR 0.80, 95% CI 0.69 to 0.93, P value = 0.004 with 14 days). Only teriflunomide at a dose of 14 mg/day reduced the number of participants with disability progression over one year (RR 0.55, 95% CI 0.36 to 0.84, P value = 0.006) or two years (RR 0.74, 95% CI 0.56 to 0.96, P value = 0.02). When taking the effect of drop-outs into consideration, the likely-case scenario analyses still showed a benefit in reducing the number of participants with at least one relapse, but not for the number of participants with disability progression. Both doses also reduced the annualized relapse rate and the number of gadolinium-enhancing T1-weighted lesions over two years. Quality of evidence for relapse outcomes at one year or at two years was low, while for disability progression at one year or at two years was very low.When compared to IFNβ-1a, teriflunomide at a dose of 14 mg/day had a similar efficacy to IFNβ-1a in reducing the proportion of participants with at least one relapse over one year, while teriflunomide at a dose of 7 mg/day was inferior to IFNβ-1a (RR 1.52, 95% CI 0.87 to 2.67, P value = 0.14; 215 participants with 14 mg/day and RR 2.74, 95% CI 1.66 to 4.53, P value < 0.0001; 213 participants with 7 mg/day). However, the quality of evidence was very low.In terms of safety profile, the most common adverse events associated with teriflunomide were diarrhoea, nausea, hair thinning, elevated alanine aminotransferase, neutropenia and lymphopenia. These adverse events had a dose-related effects and rarely led to treatment discontinuation.

AUTHORS' CONCLUSIONS

There was low-quality evidence to support that teriflunomide at a dose of 7 mg/day or 14 mg/day as monotherapy reduces both the number of participants with at least one relapse and the annualized relapse rate over one year or two years of treatment in comparison with placebo. Only teriflunomide at a dose of 14 mg/day reduced the number of participants with disability progression and delayed the progression of disability over one year or two years, but the quality of the evidence was very low. The quality of available data was too low to evaluate the benefit teriflunomide as monotherapy versus IFNβ-1a or as combination therapy with IFNβ. The common adverse effects were diarrhoea, nausea, hair thinning, elevated alanine aminotransferase, neutropenia and lymphopenia. These adverse effects were mostly mild-to-moderate in severity, but had a dose-related effect. New studies of high quality and longer follow-up are needed to evaluate the comparative benefit of teriflunomide on these outcomes and the safety in comparison with other DMTs.

Multiple sclerosis--new treatment modalities

Ever since the introduction of the first disease modifying therapies, the concept of multiple sclerosis treatment algorithms developed ceaselessly. The increasing number of available drugs is paralleled by impelling issue of ensuring the most appropriate treatment to the right patient at the right time. The purpose of this review is to describe novel agents recently approved for multiple sclerosis treatment, namely teriflunomide, alemtuzumab and dimethylfumarate, focusing on mechanism of action, efficacy data in experimental setting, safety and tolerability. The place in therapy of newer treatment implies careful balancing of risk-benefit profile as well as accurate patient selection. Hence the widening of therapeutic arsenal provides greater opportunity for personalized therapy but also entails a complex trade-off between efficacy, tolerability, safety and eventually patient preference.

Leflunomide and teriflunomide: altering the metabolism of pyrimidines for the treatment of autoimmune diseases

Leflunomide modulates T-cell responses and induces a shift from the Th1 to Th2 subpopulation. This process results in a beneficial effect in diseases in which there is good evidence that T cells play a major role in both initiation and perpetuation of the inflammatory condition. Leflunomide has been successfully used for treating rheumatoid arthritis and psoriatic arthritis for many years. The active metabolite of leflunomide is teriflunomide, which has been approved for treating multiple sclerosis. Teriflunomide, just like the mother drug, inhibits dihydro-orotate dehydrogenase and synthesis of pyrimidine. The present review presents and discusses the safety profiles of leflunomide and teriflunomide, two drugs that are indeed the same, considering that much can be learned from the reported side effects of both.

Update on the surgical treatment for rheumatoid arthritis of the wrist and hand

Surgical procedures for the treatment of rheumatoid arthritis are aimed at restoring function and decreasing pain. Over the past four decades multiple procedures have been described in the management of early and late disease. This article will review the most common forms of surgery used in the treatment of rheumatoid arthritis.

How do we manage and treat a patient with multiple sclerosis at risk of tuberculosis?

Tuberculosis continues to be a serious health problem worldwide. The disease continues to be underdiagnosed and not properly treated. In conditions that affect the immune system, such as multiple sclerosis (MS), latent tuberculosis may thrive and reactivate during the use of immunomodulatory and immunosuppressive drugs. Among the best treatment options for patients with latent or active tuberculosis who have MS are IFN-β, glatiramer acetate and mitoxantrone. Drugs leading to a reduced number and/or function of lymphocytes should be avoided or used with caution. Tuberculosis must always be investigated in patients with MS and treated with rigor.

Molecular pharmacodynamics of new oral drugs used in the treatment of multiple sclerosis

New oral drugs have considerably enriched the therapeutic armamentarium for the treatment of multiple sclerosis. This review focuses on the molecular pharmacodynamics of fingolimod, dimethyl fumarate (BG-12), laquinimod, and teriflunomide. We specifically comment on the action of these drugs at three levels: 1) the regulation of the immune system; 2) the permeability of the blood-brain barrier; and 3) the central nervous system. Fingolimod phosphate (the active metabolite of fingolimod) has a unique mechanism of action and represents the first ligand of G-protein-coupled receptors (sphingosine-1-phosphate receptors) active in the treatment of multiple sclerosis. Dimethyl fumarate activates the nuclear factor (erythroid-derived 2)-related factor 2 pathway of cell defense as a result of an initial depletion of reduced glutathione. We discuss how this mechanism lies on the border between cell protection and toxicity. Laquinimod has multiple (but less defined) mechanisms of action, which make the drug slightly more effective on disability progression than on annualized relapse rate in clinical studies. Teriflunomide acts as a specific inhibitor of the de novo pyrimidine biosynthesis. We also discuss new unexpected mechanisms of these drugs, such as the induction of brain-derived neurotrophic factor by fingolimod and the possibility that laquinimod and teriflunomide regulate the kynurenine pathway of tryptophan metabolism.

Teriflunomide and its mechanism of action in multiple sclerosis

Treatment of multiple sclerosis (MS) is challenging: disease-modifying treatments (DMTs) must both limit unwanted immune responses associated with disease initiation and propagation (as T and B lymphocytes are critical cellular mediators in the pathophysiology of relapsing MS), and also have minimal adverse impact on normal protective immune responses. In this review, we summarize key preclinical and clinical data relating to the proposed mechanism of action of the recently approved DMT teriflunomide in MS. Teriflunomide selectively and reversibly inhibits dihydro-orotate dehydrogenase, a key mitochondrial enzyme in the de novo pyrimidine synthesis pathway, leading to a reduction in proliferation of activated T and B lymphocytes without causing cell death. Results from animal experiments modelling the immune activation implicated in MS demonstrate reductions in disease symptoms with teriflunomide treatment, accompanied by reduced central nervous system lymphocyte infiltration, reduced axonal loss, and preserved neurological functioning. In agreement with the results obtained in these model systems, phase 3 clinical trials of teriflunomide in patients with MS have consistently shown that teriflunomide provides a therapeutic benefit, and importantly, does not cause clinical immune suppression. Taken together, these data demonstrate how teriflunomide acts as a selective immune therapy for patients with MS.

Immunological mechanism of action and clinical profile of disease-modifying treatments in multiple sclerosis

Multiple sclerosis (MS) is a life-long, potentially debilitating disease of the central nervous system (CNS). MS is considered to be an immune-mediated disease, and the presence of autoreactive peripheral lymphocytes in CNS compartments is believed to be critical in the process of demyelination and tissue damage in MS. Although MS is not currently a curable disease, several disease-modifying therapies (DMTs) are now available, or are in development. These DMTs are all thought to primarily suppress autoimmune activity within the CNS. Each therapy has its own mechanism of action (MoA) and, as a consequence, each has a different efficacy and safety profile. Neurologists can now select therapies on a more individual, patient-tailored basis, with the aim of maximizing potential for long-term efficacy without interruptions in treatment. The MoA and clinical profile of MS therapies are important considerations when making that choice or when switching therapies due to suboptimal disease response. This article therefore reviews the known and putative immunological MoAs alongside a summary of the clinical profile of therapies approved for relapsing forms of MS, and those in late-stage development, based on published data from pivotal randomized, controlled trials.

Optimizing therapeutics in the management of patients with multiple sclerosis: a review of drug efficacy, dosing, and mechanisms of action

Multiple sclerosis (MS) is a debilitating neurological disorder that affects nearly 2 million adults, mostly in the prime of their youth. An environmental trigger, such as a viral infection, is hypothesized to initiate the abnormal behavior of host immune cells: to attack and damage the myelin sheath surrounding the neurons of the central nervous system. While several other pathways and disease triggers are still being investigated, it is nonetheless clear that MS is a heterogeneous disease with multifactorial etiologies that works independently or synergistically to initiate the aberrant immune responses to myelin. Although there are still no definitive markers to diagnose the disease or to cure the disease per se, research on management of MS has improved many fold over the past decade. New disease-modifying therapeutics are poised to decrease immune inflammatory responses and consequently decelerate the progression of MS disease activity, reduce the exacerbations of MS symptoms, and stabilize the physical and mental status of individuals. In this review, we describe the mechanism of action, optimal dosing, drug administration, safety, and efficacy of the disease-modifying therapeutics that are currently approved for MS therapy. We also briefly touch upon the new drugs currently under investigation, and discuss the future of MS therapeutics.

Teriflunomide attenuates immunopathological changes in the dark agouti rat model of experimental autoimmune encephalomyelitis

Teriflunomide is an oral disease-modifying therapy recently approved in several locations for relapsing-remitting multiple sclerosis. To gain insight into the effects of teriflunomide, immunocyte population changes were measured during progression of experimental autoimmune encephalomyelitis in Dark Agouti rats. Treatment with teriflunomide attenuated levels of spinal cord-infiltrating T cells, natural killer cells, macrophages, and neutrophils. Teriflunomide also mitigated the disease-induced changes in immune cell populations in the blood and spleen suggesting an inhibitory effect on pathogenic immune responses.

Disease modification in multiple sclerosis: an update

Although there has been unequivocal progress in the development of treatments for multiple sclerosis over the last 20&emsp14;years, currently licensed treatments have demonstrated convincing effects on disease course only with reference to relapse frequency. This review summarises the progress made, highlights the indications for, and limitations of, current disease-modifying therapies and discusses some interventions currently in development.

Teriflunomide for the Treatment of Relapsing Multiple Sclerosis

Objective: To review the pharmacology and clinical data for teriflunomide in relapsing multiple sclerosis (MS). Data Sources: A literature search from 1966 to May 2013 using PubMed/MEDLINE, Web of Science, International Pharmaceutical Abstracts, Academic Search Premiere, Science Citation Index, and the national clinical trials registry was performed using the terms teriflunomide, HMR1726, and A771726. All articles containing human clinical trial data and relevant pharmacologic information were reviewed. Study Selection/Data Extraction: Phase 2 and phase 3 clinical trials for teriflunomide were evaluated. All peer-reviewed articles with clinically relevant information were reviewed. Priority for inclusion was placed on randomized controlled trials. Data Synthesis: Three phase 2 and three phase 3 clinical trials have evaluated teriflunomide as monotherapy or as adjunctive therapy in approximately 3000 patients with relapsing forms of MS. The phase 3 studies used annualized relapse rate, magnetic resonance imaging changes, and Expanded Disability Status Scale scores as outcome measures. One additional Phase 3 clinical study is ongoing. The annualized relapse rates and magnetic resonance imaging findings were improved compared to those with placebo and similar to or improved compared with those with subcutaneously administered interferon-β-1a 44 µg thrice weekly. Durability of response is supported by open-label extension studies. Common adverse events include increased liver function enzymes, alopecia, diarrhea, influenza, nausea, and paresthesias. Treatment discontinuation was not common and occurred in approximately 10% of patients in phase 3 studies. Conclusions: Teriflunomide is an effective and safe oral treatment option for relapsing MS. It can be used as monotherapy or added to an interferon or glatiramer acetate. It reduces the rate of relapse and may slow disease progression. The advantages of this drug are the convenience of oral administration and good tolerability. The disadvantage is the lack of long-term safety data and data about the benefit of combination therapy.

Teriflunomide

Teriflunomide is a novel disease-modifying agent that was recently approved for use in the treatment of multiple sclerosis (MS). Teriflunomide has demonstrated clinical efficacy and safety in a number of large, multicenter, phase III clinical trials and is an attractive agent to add to the growing repertoire of available treatments for MS, as it has the benefit of oral administration. Furthermore, existing clinical experience with its parent drug, leflunomide, provides indirect long-term safety data. This review summarizes teriflunomide's pharmacologic properties, pivotal clinical trials, and safety profile, and ends with a discussion of the role of teriflunomide in the context of current and emerging MS treatment options.

Teriflunomide for oral therapy in multiple sclerosis

Teriflunomide, the active metabolite of an approved antirheumatic drug, is an emerging oral therapy for multiple sclerosis (MS). Next to the inhibition of pyrimidine biosynthesis and proliferation of activated lymphocytes, it seems to have multiple anti-inflammatory and immunomodulating effects. Phase II and III clinical trials in relapsing MS demonstrated favorable safety and tolerability of the drug, as well as clinical efficacy, with a significant reduction of relapse rate, comparable with those of the available injectable immunomodulatory agents. While multiple other studies with teriflunomide are currently ongoing, its exact place in future treatment algorithms for MS is difficult to predict. It may be a good alternative for patients wishing to have an oral treatment with relatively large data regarding long-term safety.

An update of teriflunomide for treatment of multiple sclerosis

There are a number of oral agents emerging as potential disease-modifying agents in multiple sclerosis (MS). Among these investigational agents, teriflunomide has shown promise in large, multicenter, phase III clinical trials with respect to safety and efficacy in relapsing MS patients, and is the latest disease-modifying agent approved for use in MS patients in the United States. This review will summarize teriflunomide’s historical development, clinical pharmacology, studies in animals, clinical trials, and safety data, and will end with a discussion of the role of teriflunomide in MS in the context of existing treatment options.

Role of oral teriflunomide in the management of multiple sclerosis

The landscape of the treatment of relapsing-remitting multiple sclerosis is changing fast. Several oral treatments have shown benefit and generate much interest because of the convenience of their administration. Two oral compounds, fingolimod and teriflunomide, have been approved in relapsing-remitting multiple sclerosis, while others have completed Phase III trials and are awaiting review for registration. Teriflunomide is a pyrimidine synthesis inhibitor with selective immunomodulatory and immunosuppressive properties that have shown consistent efficacy in clinical trials, and a good safety profile. This paper provides an overview of the mechanisms of action and efficacy and safety results from clinical trials with this drug. The role of teriflunomide in the treatment of relapsing-remitting multiple sclerosis is discussed.

Teriflunomide for multiple sclerosis

BACKGROUND

Disease-modifying therapies (DMTs) for multiple sclerosis aim to specifically reduce inflammation in relapsing multiple sclerosis and promote neuroprotection and neurorepair in progressive multiple sclerosis (MS). Most of the currently available disease-modifying drugs (DMDs) require regular and frequent parenteral administration, which imposes a burden on patients and leads to reduced adherence. Not all MS patients respond adequately to current DMDs and, therefore, alternative MS treatments with less invasive routes of administration and new modes of action are required to expand the current treatment repertoire, increase adherence, and thereby improve efficacy. As one of the oral DMDs, teriflunomide is a potentially promising new oral agent in the treatment of relapsing MS. It inhibits dihydro-orotate dehydrogenase (DHODH) and the synthesis of pyrimidine and has selective immunosuppressive and immunomodulatory properties.

OBJECTIVES

To explore the potential benefits of teriflunomide and so expand the available DMT options, the effectiveness and safety of teriflunomide, as monotherapy or combination therapy, were assessed versus placebo or approved DMDs (IFN-β, glatiramer acetate, natalizumab, mitoxantrone, fingolimod) for modifying disease in patients with MS.

SEARCH METHODS

The Trials Search Co-ordinator searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Specialised Register (27 June 2012). We checked references in identified trials and manually searched the reports (2004 to June 2012) from neurological associations and MS societies. We also communicated with researchers participating in trials on teriflunomide and contacted Sanofi-Aventis.

SELECTION CRITERIA

All randomised, double-blind, controlled, parallel clinical trials (RCTs) with a length of follow-up of at least one year evaluating teriflunomide, as monotherapy or combination therapy, versus placebo or other treatments (IFN-β, glatiramer acetate, natalizumab, mitoxantrone, fingolimod) for patients with MS. Titles and abstracts of the citations retrieved by the literature search were screened independently for inclusion or exclusion by two review authors. Any disagreement regarding inclusion was resolved by discussion or by referral to a third assessor if necessary.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. Disagreements were discussed and resolved by consensus among review authors. Principal investigators of included studies were contacted for additional data or confirmation of information.

MAIN RESULTS

Two studies involving 1204 people evaluated the efficacy and safety of teriflunomide 7 mg and 14 mg, alone or with add-on IFN-β, versus placebo for adult patients with relapsing forms of MS (relapsing-remitting (RRMS), secondary progressive (SPMS) with relapse, and progressive relapsing MS (PRMS)) and an entry Expanded Disability Status Scale (EDSS) score of ≤ 5.5. Both studies had high attrition bias (26.8% and 36.4% attrition respectively). Teriflunomide 7 or 14 mg alone had potential benefits on reducing relapse rates, and alone or with add-on IFN-β was safe for patients with relapsing forms of MS in the short term. The most common adverse events included nasopharyngitis, headache, diarrhoea, fatigue, elevated alanine aminotransferase levels, nausea, hair thinning or decreased hair density, influenza, back pain, urinary tract infection, and pain in the arms or legs. Four ongoing trials were identified.

AUTHORS' CONCLUSIONS

We found low-level evidence for the use of teriflunomide as a disease-modifying therapy for MS, due to the limited quality of the available RCTs. We did not conduct meta-analysis because of the clinical and methodological diversity of the included studies. Short-term teriflunomide, 7 or 14 mg alone or with add-on IFN-β, was safe for patients with relapsing MS. Both teriflunomide 7 and 14 mg alone had potential benefits for patients with relapsing forms of MS. We are waiting for the publication of ongoing trials. RCTs with high methodological quality and longer periods of observation are needed to assess safety, disability progression, neuroprotection and quality of life.

Benefits versus risks of latest therapies in multiple sclerosis: a perspective review

Disease-modifying treatments for multiple sclerosis (MS) have now been available for almost 20 years. Interferon β (IFN-β) products and glatiramer acetate (GA) were the first available options and are now considered first-line agents for the treatment of MS. These medications have several years of favorable safety data, but are not effective in completely controlling disease activity in all patients. Alternate medications with increased efficacy have been developed and identified; however, these newer medications have known or potential safety concerns which have prompted clinicians to view them as second-line agents. Highly efficacious and safe medications are continuously being searched for and developed; however, time is needed to establish the long-term safety of any new therapeutic agent. MS practitioners are faced with the clinical dilemma of treating patients with very safe modestly effective medications or using more efficacious and potentially riskier agents. The risk-benefit profile of every medication will have to be weighed carefully and clinicians will need to gage the risk tolerance of each patient in order to tailor treatment. This review will summarize benefits and risks of recently approved therapies in MS and will provide a perspective view on the placement of these medications within the MS treatment algorithm in the near future.

What do effective treatments for multiple sclerosis tell us about the molecular mechanisms involved in pathogenesis?

Multiple sclerosis is a potentially debilitating disease of the central nervous system. A concerted program of research by many centers around the world has consistently demonstrated the importance of the immune system in its pathogenesis. This knowledge has led to the formal testing of a number of therapeutic agents in both animal models and humans. These clinical trials have shed yet further light on the pathogenesis of MS through their sometimes unexpected effects and by their differential effects in terms of impact on relapses, progression of the disease, paraclinical parameters (MRI) and the adverse events that are experienced. Here we review the currently approved medications for the commonest form of multiple sclerosis (relapsing-remitting) and the emerging therapies for which preliminary results from phase II/III clinical trials are available. A detailed analysis of the molecular mechanisms responsible for the efficacy of these medications in multiple sclerosis indicates that blockade or modulation of both T- and B-cell activation and migration pathways in the periphery or CNS can lead to amelioration of the disease. It is hoped that further therapeutic trials will better delineate the pathogenesis of MS, ultimately leading to even better treatments with fewer adverse effects.

Suppressed wound healing in a patient with rheumatoid arthritis taking leflunomide (arava)

Although patients with rheumatoid arthritis taking disease-modifying antirheumatic drugs (DMARDs) are monitored for various medication adverse events, DMARDs, and leflunomide in particular, have effects that are not observed clinically, specifically adverse effects on wound healing.

Emerging oral immunomodulating agents - focus on teriflunomide for the treatment of multiple sclerosis

Treatment for multiple sclerosis (MS), a chronic disease of the central nervous system, has historically relied exclusively on the use of injectable therapies. As the disease requires lifelong therapy, the development of oral therapies that are safe and effective would provide a more convenient dosage form that may improve patient compliance. One oral medication (fingolimod) was recently approved for treatment of MS. Teriflunomide, an immunomodulator, is one of four oral therapies currently undergoing Phase III trials. Teriflunomide exerts its clinical effects via selective inhibition of de novo pyrimidine synthesis, primarily targeting proliferating T and B lymphocytes in the periphery. Teriflunomide was effective as monotherapy in reducing magnetic resonance imaging lesions and annual relapse rates in Phase II and Phase III trials. When teriflunomide was added to interferon or glatiramer acetate therapy in Phase II trials, teriflunomide reduced magnetic resonance imaging lesions significantly more than either interferon or glatiramer acetate alone. Treatment-emergent adverse events occurred at similar rates among all groups in teriflunomide studies, with a trend towards a higher treatment emergent adverse events rate in the higher dosage group of teriflunomide (14 mg daily). Treatment discontinuations in teriflunomide trials were relatively low, suggesting that teriflunomide monotherapy is well tolerated. This article reviews the mode of action of teriflunomide, its pharmacokinetic, clinical efficacy, and safety profiles.