Evidence Report: The efficacy and safety of mitoxantrone (Novantrone) in the treatment of multiple sclerosis: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology

Current understanding of cardiovascular autonomic dysfunction in multiple sclerosis

Autoimmune diseases, including multiple sclerosis (MS), are proven to increase the likelihood of developing cardiovascular disease (CVD) due to a robust systemic immune response and inflammation. MS can lead to cardiovascular abnormalities that are related to autonomic nervous system dysfunction by causing inflammatory lesions surrounding tracts of the autonomic nervous system in the brain and spinal cord. CVD in MS patients can affect an already damaged brain, thus worsening the disease course by causing brain atrophy and white matter disease. Currently, the true prevalence of cardiovascular dysfunction and associated death rates in patients with MS are mostly unknown and inconsistent. Treating vascular risk factors is recommended to improve the management of this disease. This review provides an updated summary of CVD prevalence in patients with MS, emphasizing the need for more preclinical studies using animal models to understand the pathogenesis of MS better. However, no distinct studies exist that explore the temporal effects and etiopathogenesis of immune/inflammatory cells on cardiac damage and dysfunction associated with MS, particularly in the cardiac myocardium. To this end, a thorough investigation into the clinical presentation and underlying mechanisms of CVD must be conducted in patients with MS and preclinical animal models. Additionally, clinicians should monitor for cardiovascular complications while prescribing medications to MS patients, as some MS drugs cause severe CVD.

Nesfatin-1: A Biomarker and Potential Therapeutic Target in Neurological Disorders

Nesfatin-1 is a novel adipocytokine consisting of 82 amino acids with anorexic and anti-hyperglycemic properties. Further studies of nesfatin-1 have shown it to be closely associated with neurological disorders. Changes in nesfatin-1 levels are closely linked to the onset, progression and severity of neurological disorders. Nesfatin-1 may affect the development of neurological disorders and can indicate disease evolution and prognosis, thus informing the choice of treatment options. In addition, regulation of the expression or level of nesfatin-1 can improve the level of neuroinflammation, apoptosis, oxidative damage and other indicators. It is demonstrated that nesfatin-1 is involved in neuroprotection and may be a therapeutic target for neurological disorders. In this paper, we will also discuss the role of nesfatin-1 as a biomarker in neurological diseases and its potential mechanism of action in neurological diseases, providing new ideas for the diagnosis and treatment of neurological diseases.

Drugs to Treat Neuroinflammation in Neurodegenerative Disorders

Neuroinflammation is associated with disorders of the nervous system, and it is induced in response to many factors, including pathogen infection, brain injury, toxic substances, and autoimmune diseases. Astrocytes and microglia have critical roles in neuroinflammation. Microglia are innate immune cells in the central nervous system (CNS), which are activated in reaction to neuroinflammation-inducing factors. Astrocytes can have pro- or anti-inflammatory responses, which depend on the type of stimuli presented by the inflamed milieu. Microglia respond and propagate peripheral inflammatory signals within the CNS that cause low-grade inflammation in the brain. The resulting alteration in neuronal activities leads to physiological and behavioral impairment. Consequently, activation, synthesis, and discharge of various pro-inflammatory cytokines and growth factors occur. These events lead to many neurodegenerative conditions, such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis discussed in this study. After understanding neuroinflammation mechanisms and the involvement of neurotransmitters, this study covers various drugs used to treat and manage these neurodegenerative illnesses. The study can be helpful in discovering new drug molecules for treating neurodegenerative disorders.

Therapeutical growth in oligodendroglial fate induction via transdifferentiation of stem cells for neuroregenerative therapy

The merits of stem cell therapy and research are undisputed due to their widespread usage in the treatment of neurodegenerative diseases and demyelinating disorders. Cell replacement therapy especially revolves around stem cells and their induction into different cell lineages both adult and progenitor - belonging to each germ layer, prior to transplantation or disease modeling studies. The nervous system is abundant in glial cells and among these are oligodendrocytes capable of myelinating new-born neurons and remyelination of axons with lost or damaged myelin sheath. But demyelinating diseases generate tremendous deficit between myelin loss and recovery. To compensate for this loss, analyze the defects in remyelination mechanisms as well as to trigger full recovery in such patients mesenchymal stem cells (MSCs) have been induced to transdifferentiate into oligodendrocytes. But such experiments are riddled with problems like prolonged, tenuous and complicated protocols that stretch longer than the time taken for the spread of demyelination-associated after-effects. This review delves into such protocols and the combinations of different molecules and factors that have been recruited to derive bona fide oligodendrocytes from in vitro differentiation of embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and MSCs with special focus on MSC-derived oligodendrocytes.

Evaluation of Edaravone effects on the differentiation of human adipose derived stem cells into oligodendrocyte cells in multiple sclerosis disease in rats

AIMS

Among all the treatments for Multiple Sclerosis, stem cell transplantation, such as ADSCs, has attracted a great deal of scientific attention. On the other hand, Edaravone, as an antioxidant component, in combination with stem cells, could increase the survival and differentiation potential of stem cells.

MAIN METHODS

42 rats were divided into: Control, Cuprizone (CPZ), Sham, Edaravone (Ed), hADSCs, and Ed/hADSCs groups. Following induction of cuprizone, induced MS model, behavioral tests were designed to evaluate motor function during. Luxal fast blue staining was done to measure the level of demyelination and remyelination. Immunofluorescent staining was used to evaluate the amount of MBP, OLIG2, and MOG proteins. The mRNA levels of human MBP, MOG, and OLIG2 and rat Mbp, Mog, and Olig2 were determined via RT-PCR.

KEY FINDINGS

Flow cytometry analysis exhibited that the extracted cells were positive for CD73 (93.8 ± 3%) and CD105 (91.6 ± 3%), yet negative for CD45 (2.06 ± 0.5%). Behavioral tests, unveiled a significant improvement in the Ed (P < 0.001), hADSCs (P < 0.001), and Ed/hADSCs (P < 0.001) groups compared to the others. In the Ed/hADSCs group, the myelin density was significantly higher than that in the Ed treated and hADSCs treated groups (P < 0.01). Edaravone and hADSCs increased the expression of Mbp, Mog, and Olig2 genes in the cuprizone rat models. Moreover, significant differences were seen between the Ed treated and hADSCs treated groups and the Ed/hADSCs group (P < 0.05 for Mbp and Olig2 and P < 0.01 for Mog).

SIGNIFICANCE

Edaravone in combination with hADSCs reduced demyelination and increased oligodendrogenesis in the cuprizone rat models.

Monomethyl Fumarate (MMF, Bafiertam) for the Treatment of Relapsing Forms of Multiple Sclerosis (MS)

Multiple sclerosis (MS) is a prevalent neurologic autoimmune disorder affecting two million people worldwide. Symptoms include gait abnormalities, perception and sensory losses, cranial nerve pathologies, pain, cognitive dysfunction, and emotional aberrancies. Traditional therapy includes corticosteroids for the suppression of relapses and injectable interferons. Recently, several modern therapies-including antibody therapy and oral agents-were approved as disease-modifying agents. Monomethyl fumarate (MMF, Bafiertam) is a recent addition to the arsenal available in the fight against MS and appears to be well-tolerated, safe, and effective. In this paper, we review the evidence available regarding the use of monomethyl fumarate (Bafiertam) in the treatment of relapsing-remitting MS.

Therapy of Pediatric-Onset Multiple Sclerosis: State of the Art, Challenges, and Opportunities

Treatment of pediatric-onset multiple sclerosis (POMS) has been tailored after observational studies and data obtained from clinical trials in adult-onset multiple sclerosis (AOMS) patients. There are an increasing number of new therapeutic agents for AOMS, and many will be formally studied for use also in POMS. However, there are important efficacy and safety concerns regarding the use of these therapies in children and young adults. This review will discuss the current state of the art of POMS therapy and will focus on the newer therapies (oral and infusion disease-modifying drugs) and on those still currently under investigation.

A review of possible therapies for multiple sclerosis

Multiple sclerosis (MS) is an autoimmune chronic inflammatory disease of the central nervous system with a wide range of symptoms, like executive function defect, cognitive dysfunction, blurred vision, decreased sensation, spasticity, fatigue, and other symptoms. This neurological disease is characterized by the destruction of the blood-brain barrier, loss of myelin, and damage to neurons. It is the result of immune cells crossing the blood-brain barrier into the central nervous system and attacking self-antigens. Heretofore, many treatments proved that they can retard the progression of the disease even though there is no cure. Therefore, treatments aimed at improving patients' quality of life and reducing adverse drug reactions and costs are essential. In this review, the treatment approaches to alleviate the progress of MS include the following: pharmacotherapy, antibody therapy, cell therapy, gene therapy, and surgery. The current treatment methods of MS are described in terms of the prevention of myelin shedding, the promotion of myelin regeneration, and the protection of neurons.

Health care resource utilization and disease modifying treatment use in multiple sclerosis patients by age and insurance type

OBJECTIVE

The objective of this study was to describe and compare health care resource utilization (HCRU) and disease modifying treatment (DMT) use among US adults <65 years with multiple sclerosis (MS), across commercial and Medicare Advantage plans.

METHODS

Medical and pharmacy claims data from commercial and Medicare Advantage with Part D (MAPD) plans were extracted for MS patients age 18 - 64 identified between 1 January 2014 and 31 May 2017. Comparisons were made between commercial and MAPD enrollees for all-cause HCRU and DMT use over 1 year, overall and by 5 year age groups.

RESULTS

A total of 28,427 MS patients were identified; two-thirds (67%) had commercial coverage. MAPD patients had statistically significantly higher mean counts of all-cause inpatient, emergency room (ER) and ambulatory visits compared to commercial patients. The significant differences were evident in all age groups ≥30 years, except for ER visits in the 40-44 and 60-64 age groups. MAPD patients had statistically significantly lower prevalence of DMT use compared to commercial patients in all age groups starting at ≥35 years.

CONCLUSION

MAPD patients had a higher burden of medical HCRU compared to their commercially insured counterparts, most likely due primarily to their more advanced disease state and higher level of MS-related disability. Reasons for lower prevalence of DMT use among MAPD patients may include their more advanced disease state, older age and higher prevalence of comorbid conditions compared with commercially insured patients, as well as more restrictive formularies for MAPD vs. commercial plans. These findings suggest that there may be an opportunity for recently approved DMTs indicated for active secondary progressive MS to fulfill an unmet need for treatment among MS patients <65 years without contraindicated comorbid conditions who are enrolled in MAPD plans. Novel therapies under development to delay progression may help keep MS patients of working age in the work force.

ELAVL1 Role in Cell Fusion and Tunneling Membrane Nanotube Formations with Implication to Treat Glioma Heterogeneity

Homotypic and heterotypic cell fusions via permanent membrane fusions and temporal tunneling nanotube formations in the glioma microenvironment were recently documented in vitro and in vivo and mediate glioma survival, plasticity, and recurrence. Chronic inflammation, a hypoxic environment, aberrant mitochondrial function, and ER stress due to unfolded protein accumulation upregulate cell fusion events, which leads to tumor heterogeneity and represents an adaptive mechanism to promote tumor cell survival and plasticity in cytotoxic, nutrient-deprived, mechanically stressed, and inflammatory microenvironments. Cell fusion is a multistep process, which consists of the activation of the cellular stress response, autophagy formation, rearrangement of cytoskeletal architecture in the areas of cell-to-cell contacts, and the expression of proinflammatory cytokines and fusogenic proteins. The mRNA-binding protein of ELAV-family HuR is a critical node, which orchestrates the stress response, autophagy formation, cytoskeletal architecture, and the expression of proinflammatory cytokines and fusogenic proteins. HuR is overexpressed in gliomas and is associated with poor prognosis and treatment resistance. Our review provides a link between the HuR role in the regulation of cell fusion and tunneling nanotube formations in the glioma microenvironment and the potential suppression of these processes by different classes of HuR inhibitors.

Induction Versus Escalation in Multiple Sclerosis: A 10-Year Real World Study

In this independent, multicenter, post-marketing study, we directly compare induction immunosuppression versus escalation strategies on the risk of reaching the disability milestone of Expanded Disability Status Scale (EDSS) ≥ 6.0 over 10 years in previously untreated patients with relapsing-remitting multiple sclerosis. We collected data of patients who started interferon beta (escalation) versus mitoxantrone or cyclophosphamide (induction) as initial treatment. Main eligibility criteria included an EDSS score ≤ 4.0 at treatment start and either ≥ 2 relapses or 1 disabling relapse with evidence of ≥ 1 gadolinium-enhancing lesion at magnetic resonance imaging scan in the pre-treatment year. Since patients were not randomized to treatment group, we performed a propensity score (PS)-based matching procedure to select individuals with homogeneous baseline characteristics. Comparisons were then conducted using Cox models stratified by matched pairs. Overall, 75 and 738 patients started with induction and escalation, respectively. Patients in the induction group were older and more disabled than those in the escalation group (p < 0.05). The PS-matching procedure retained 75 patients per group. In the re-sampled population, a lower proportion of patients reached the outcome after induction (21/75, 28.0%) than escalation (29/75, 38.7%) (hazard ratio = 0.48; p = 0.024). Considering the whole sample, serious adverse events occurred more frequently after induction (8/75, 10.7%) than escalation (18/738, 2.4%) (odds ratio = 3.36, p = 0.015). These findings suggest that, in patients with poor prognostic factors, induction was more effective than escalation in reducing the risk of reaching the disability milestone, albeit with a worse safety profile. Future studies are warranted to explore if newer induction agents may provide a more advantageous long-lasting risk:benefit profile.

Mitoxantrone in relapsing-remitting and rapidly progressive multiple sclerosis: Ten-year clinical outcomes post-treatment with mitoxantrone

BACKGROUND

Mitoxantrone (MTX) has been used as an effective disease modifying treatment (DMT) in multiple sclerosis (MS). Evidence from studies demonstrates benefits of reduced relapse rates, MRI disease activity and disability progression in patients treated with MTX. While effective, MTX use has been limited due to potential adverse effects (AE) ranging from mild to potentially life-threatening AEs such as cardiotoxicity, bone marrow suppression and hematological malignancies. In this study we aimed to review the long-term clinical efficacy, tolerability, and AE profile of treatment with MTX in patients both with relapsing-remitting and rapidly progressive MS over a 10-year follow-up period.

METHODS

We collected prospective data of 70 patients with relapsing-remitting and rapidly progressive MS treated with MTX and followed-up over a 10-year period. Expanded disability status scale (EDSS) scores and annualized relapse rates (ARR) were assessed 1 year prior to MTX treatment, and at different time points (1, 2, 3, 5 and 10 years) during follow-up. We recorded the time to first relapse and 0.5-point EDSS increase to assess efficacy. We also obtained frequency data on AEs and patients withdrawn from treatment.

RESULTS

70 patients were started on treatment with MTX with 53 patients (34 relapsing-remitting MS, 19 progressive disease) completing the course. Mean EDSS progressed from 5.5 to 6.5 in the relapsing-remitting group and 6.7 to 9.0 in the progressive group over the study period. ARR in the RRMS group reduced at all time points from 2.2 prior to MTX to 0.3 by year 10. We reported 3 significant AEs, one chicken pox and subsequent acute promyelocytic leukemia, one left ventricular systolic dysfunction, one pancytopenia. The commonest AE reported was nausea/vomiting in 28 (40%) patients. Seventeen patients (5 relapsing-remitting, 12 progressive disease) stopped treatment. In fifteen (87%) of these this was due to lack of efficacy. In the remaining 2 patients, MTX was stopped due to one patient developing chicken pox and the other developing first-degree heart block.

CONCLUSION

Our study demonstrated that MTX is an effective disease modifying treatment for relapsing-remitting MS with a well-established risk profile. While MTX is now used less frequently, many MS and neurology services continue to follow-up patients who have been treated with MTX previously. Therefore, understanding the long-term effects risks and benefits remains relevant in this patient group. MTX is also a low-cost treatment in comparison to other high efficacy MS disease-modifying treatments and this may be beneficial in low resource settings.

Clinically Assessed Walking Capacity Versus Real-World Walking Performance in People with Multiple Sclerosis

Background

Ecological validity is an important psychometric property when assessing function. How a person with multiple sclerosis (MS) performs in clinical settings and in natural environments can be quite different. Walking is the most frequently assessed and recommended way to maintain health in a progressive disease such as MS. The objective was to estimate the extent to which clinical tests of walking capacity differ from real-world walking performance in people with MS.

Methods

Ninety-eight women and 27 men with MS were assessed using the 6-Minute Walk Test (6MWT) and wore an accelerometer for 7 consecutive days. Mean number of steps, mean number of steps at a brisk cadence or faster, and cumulative time per week spent walking at a brisk cadence or faster were regressed on 6MWT categories using quantile (median) regression. Contiguous steps were grouped into bouts of less than 5 minutes and 5 minutes or longer, and number of bouts 5 minutes or longer was regressed on 6MWT categories using a zero-inflated Poisson model.

Results

A total of 869 patient-days of accelerometer data were available. Mean total number of steps per day was greater for people with higher walking capacity (6MWT distance, ≥600 m). However, this group spent a small proportion of time walking at higher cadence bands. Compared with people with 6MWT distance of at least 600 m, people walking less than 500 m had approximately half the rate of walking bouts of 5 minutes or longer. Positive mood and fewer exercise barriers predicted more walking bouts of at least 5 minutes.

Conclusions

Study participants with MS spent a small proportion of time walking at a health-promoting intensity.

Managing Risks with Immune Therapies in Multiple Sclerosis

Since the introduction of the interferons in the 1990s, a multitude of different immunomodulatory and immunosuppressant disease-modifying therapies for multiple sclerosis (MS) have been developed. They have all shown positive effects on clinical endpoints such as relapse rate and disease progression and are a heterogeneous group of therapeutics comprising recombinant pegylated and non-pegylated interferon-β variants, peptide combinations, monoclonal antibodies, and small molecules. However, they have relevant side effect profiles, which necessitate thorough monitoring and straightforward patient education. In individual cases, side effects can be severe and potentially life-threatening, which is why knowledge about (neurological and non-neurological) adverse drug reactions is essential for prescribing neurologists as well as general practitioners. This paper aims to provide an overview of currently available MS therapies, their modes of action and safety profiles, and the necessary therapy monitoring.

Neuroinflammatory and Demyelinating Disorders of Childhood

In this chapter, we will review monophasic and recurrent demyelinating disorders in children. We will first review consensus definitions and provide an approach to the evaluation of children with first episode of acquired demyelinating disorder. We will discuss typical clinical and radiological features of these syndromes. In the second section, we will review features of recurrent demyelinating syndromes in children, focusing on clinical presentation and treatment options.

Safety of long-term intrathecal methotrexate in progressive forms of MS

Background

There are few treatment options for multiple sclerosis (MS) patients with advanced disability [expanded disability status scale (EDSS) ⩾ 6.0]. In 2010, we reported initial results of using intrathecal methotrexate (ITMTX) in patients with progressive MS. We now report on long-term use of ITMTX. We performed a retrospective chart analysis of patients who have had 18 or more treatments to establish the ongoing safety and tolerability of ITMTX. Thus, the objective of this study was to establish the safety and tolerability of long-term therapy with (ITMTX) in patients with treatment-resistant, progressive forms of MS.

Methods

We studied 83 patients (67 secondary and 16 primary progressive) who received ITMTX 12.5 mg every 8-11 weeks for 3-10 years (range: 18-57 treatments). All patients were evaluated neurologically, and their EDSS was assessed at every treatment. In addition, all adverse events, frequency of infections, and any hospitalizations, were noted.

Results

There were no deaths, hospitalizations, or other serious adverse effects related to ITMTX. Headaches occurred at least once in 12% of patients, and transient fatigue occurred in 53% of patients. As determined by EDSS, there was no significant change from baseline status to post-treatment scores in both primary progressive MS (PPMS) and secondary progressive (SPMS) patients.

Conclusions

Pulsed ITMTX was well tolerated for up to 10 years in PPMS patients with no serious adverse effects. Although this was an open-label, retrospective analysis, and efficacy could not be studied, there was evidence of disease stabilization in many patients receiving ITMTX. It appears that long-term ITMTX is a safe therapeutic option in advanced progressive MS.

Dandelion Root and Lemongrass Extracts Induce Apoptosis, Enhance Chemotherapeutic Efficacy, and Reduce Tumour Xenograft Growth In Vivo in Prostate Cancer

Many conventional chemotherapies have indicated side effects due to a lack of treatment specificity and are thus not suitable for long-term usage. Natural health products are well-tolerated and safe for consumption, and some have pharmaceutical uses particularly for their anticancer effects. We have previously reported the anticancer efficacy of dandelion (Taraxacum officinale) root and lemongrass (Cymbopogon citratus) extracts. However, their efficacy on prostate cancer and their interactions with standard chemotherapeutics have not been studied to determine if they will be suitable for adjuvant therapies. If successful, these extracts could potentially be used in conjunction with chemotherapeutics to minimize the risk of drug-related toxicity and enhance the efficacy of the treatment. We have demonstrated that both dandelion root extract (DRE) and lemongrass extract (LGE) exhibit selective anticancer activity. Importantly, DRE and LGE addition to the chemotherapeutics taxol and mitoxantrone was determined to enhance the induction of apoptosis when compared to individual chemotherapy treatment alone. Further, DRE and LGE were able to significantly reduce the tumour burden in prostate cancer xenograft models when administered orally, while also being well-tolerated. Thus, the implementation of these well-tolerated extracts in adjuvant therapies could be a selective and efficacious approach to prostate cancer treatment.

The modulatory effects of luteolin on cyclic AMP/Ciliary neurotrophic factor signaling pathway in experimentally induced autoimmune encephalomyelitis

Multiple sclerosis (MS) is considered to be an autoimmune disorder of the central nervous system (CNS) manifested by chronic inflammation. Although its etiology is not completely understood, inflammation and apoptosis are known to be major players involved in its pathogenesis. Luteolin, the naturally occurring flavonoid, is known by strong antioxidant and anti-inflammatory properties, yet research studies about its therapeutic role in MS are still lacking. The study aimed to provide insight into effects of luteolin in experimental autoimmune encephalomyelitis (EAE) by monitoring inflammatory, apoptotic, and antioxidant biochemical parameters in addition to histological examination findings. The study included 45 adult female Wistar rats allocated to three equal groups: (a) group I: control group, (b) group II: EAE group, EAE was induced by single intradermal injection of 0.2 mL inoculum comprising 20-μg recombinant rat myelin oligodendrocyte glycoprotein (MOG), and (c) group III: luteolin-treated EAE group, luteolin was given in a dose of 10 mg/kg/day, i.p. All groups were subjected to assessment of brain ciliary neurotropic factor (CNTF) mRNA gene expression and measurement of cleaved caspase 3, nuclear factor kappa B (NF-κB), cyclic AMP (cAMP), and macrophage inflammatory protein 1 alpha (MIP-1α) by the ELISA technique, total antioxidant capacity (TAC) level is assessed spectrophotometrically. Compared with the EAE group, luteolin-treated EAE group showed upregulation of CNTF expression and significant increase in cAMP and TAC levels, while it showed significant decrease in cleaved caspase 3, NF-κB, and MIP-1α levels. Based on our data herein, luteolin may provide a promising preclinical therapeutic line in MS being anti-inflammatory, antiapoptotic, and neurotrophic agent. © 2019 IUBMB Life, 71(9):1401-1408, 2019.

Putting the best foot forward: Relationships between indicators of step quality and cadence in three gait vulnerable populations

BACKGROUND

Aging and neurological conditions like Multiple Sclerosis (MS) and Parkinson's disease (PD) make people vulnerable for gait impairments, limit function, and restrict sustained walking needed for health promotion. Walking to meet physical activity guidelines requires adequate cadence which is difficult to achieve for gait vulnerable populations.

OBJECTIVE

The objective of this study is to estimate, for seniors and people with MS or PD, the extent to which cadence is associated with heel-to-toe stepping pattern (good steps), angular velocity of ankle at heel-strike and its variability.

METHODS

A cross-sectional regression analysis was performed on data collected during walking tests using the Heel2Toe sensor.

RESULTS

Health condition (MS = 57, PD = 27, seniors = 56) had an association with cadence, independent of age and sex. Only angular velocity showed a significant relationship with cadence such that every - 50° difference in angular velocity (more negative is better) was associated with a difference of ≈3.5 steps per minute.

CONCLUSION

Adequate angular velocity occurs with an optimal heel-to-toe movement. This heel-to-toe gait can easily be targeted during therapy but technology would be an asset to sustain the relearned movement during everyday activities, Technology that provides real-time feedback for steps with adequate angular velocity at heel strike could be a valuable therapeutic adjunct.

Risks and risk management in modern multiple sclerosis immunotherapeutic treatment

In recent years, there has been a paradigm shift in the treatment of multiple sclerosis (MS) owing to the approval of a number of new drugs with very distinct mechanisms of action. All approved disease-modifying drugs primarily work directly on the immune system. However, the identification of an ‘optimal choice’ for individual patients with regard to treatment efficacy, treatment adherence and side-effect profile has become increasingly complex including conceptual as well as practical considerations. Similarly, there are peculiarities and specific requirements with regard to treatment monitoring, especially in relation to immunosuppression, the development of secondary immune-related complications, as well as the existence of drug-specific on- and off-target effects. Both classical immunosuppression and selective immune interventions generate a spectrum of potential therapy-related complications. This article provides a comprehensive overview of available immunotherapeutics for MS and their risks, detailing individual mechanisms of action and side-effect profiles. Furthermore, practical recommendations for patients treated with modern MS immunotherapeutics are provided.

Myeloid disorders after autoimmune disease

Autoimmune diseases (ADs) are associated with an increased risk not only of lymphoproliferative disorders but also of myeloid malignancies. The excess risk of myelodysplastic syndromes and/or acute myeloid leukemia is observed across several AD types, including systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disorders, multiple sclerosis, among others. The risk of developing myeloid neoplasms (MNs) is dependent on several variables, including the specific AD type, chronicity and severity of the AD, type and duration of exposure of disease modifying anti-rheumatic drugs or cytotoxics/immunosuppressives, and genetic predisposition risk. Putative triggering factors linking AD to elevated MN risk include AD-directed medications, shared genetic susceptibilities between the two disease entities, and chronic immune stimulation or bone marrow infiltration by the AD. Molecular mechanisms underpinning leukemogenesis remain largely speculative and warrant further investigation. Leukemias arising in patients with AD are not always 'therapy-related' in that MNs may develop in certain AD subtypes even among patients with no prior therapy exposure. Only a few studies have attempted to determine factors associated with MN development in AD but failed to demonstrate consistent characteristic clinical or paraclinical features. These reports have failed to demonstrate a clear correlation between individual agent exposure and subsequent leukemia development due to the low rates of therapy exposure compounded by the rarity of MN occurrence. Notwithstanding, the leukemogenic potential is best documented with agents such as azathioprine, cyclophosphamide, and mitoxantrone; this risk of MN development does not appear to be shared by biologic approaches such as anti-tumor necrosis factors-alpha inhibitors. In this article, we discuss plausible biologic mechanisms underlying MN pathogenesis in AD and review the data available on the development of MNs in patients with AD.

B-Cell Therapies in Multiple Sclerosis

B cells play a vital function in multiple sclerosis (MS) pathogenesis through an array of effector functions. All currently approved MS disease-modifying therapies alter the frequency, phenotype, or homing of B cells in one way or another. The importance of this mechanism of action has been reinforced with the successful development and clinical testing of B-cell-depleting monoclonal antibodies that target the CD20 surface antigen. Ocrelizumab, a humanized anti-CD20 monoclonal antibody, was approved by the Food and Drug Administration (FDA) in March 2017 after pivotal trials showed dramatic reductions in inflammatory disease activity in relapsing MS as well as lessening of disability progression in primary progressive MS. These and other clinical studies place B cells at the center of the inflammatory cascade in MS and provide a launching point for development of therapies that target selective pathogenic B-cell populations.

Cancer Risk in Patients with Multiple Sclerosis: Potential Impact of Disease-Modifying Drugs

In the 1990s, the first disease-modifying therapies (DMTs) for multiple sclerosis (MS) were injectable immunomodulatory (IM) drugs, including four different interferon-β preparations and glatiramer acetate. Since 2000, more than 15 immunosuppressant (IS) drugs have been used, with a more or less specific action on inflammation. These include monoclonal antibodies targeting CTL4, the integrin receptor, the interleukin (IL)-2 receptor, CD19, CD20, CD52, and the sphingosine 1 phosphate family. The association between MS and cancer has long been investigated but has led to conflicting results. No studies have reported an increased risk of cancer after long-term exposure to IM. Several reports suggest an increase in cancer risk among MS patients treated with IS such as mitoxantrone, azathioprine and cyclophosphamide. Because of their action on the immune system, and due to a lack of available long-term data, a special warning of the potential risk of cancer accompanies the use of recent IS such as cladribine, fingolimod, natalizumab or alemtuzumab. In most studies, factors such as diet, smoking, solar radiation, and hormone therapy, all of which influence cancer risk, have not been considered. For fingolimod, natalizumab, alemtuzumab, dimethyl fumarate, teriflunomide, daclizumab and ocrelizumab, risk management plans outlined by regulatory agencies are mandatory. They allow prospective detection of some red flags, in particular those for the increased risk of cancer. We review the current evidence behind the increased risk of malignancy in MS patients receiving DMTs, and provide an overview of the DMTs that are currently in use and those in clinical trials. The known risks and benefits of these therapies will be considered.

Clinical follow-up of 411 patients with relapsing and progressive multiple sclerosis 10 years after discontinuing mitoxantrone treatment: a real-life cohort study

BACKGROUND AND PURPOSE

Mitoxantrone (MITOX) has been used to treat patients with aggressive multiple sclerosis (MS) for decades. We aimed to describe the effectiveness and adverse events over 10 years post-MITOX in patients with relapsing and progressive MS from an exhaustive real-life database.

METHODS

Data from patients who received MITOX before 1 January 2006 were collected from the MS Lorraine registry. Expanded Disability Status Scale (EDSS) scores and annual relapse rates (ARRs) year by year during follow-up and the year prior to MITOX were compared. Time to the first relapse and a 1-point increase in EDSS score were used in Cox multivariate models to find associations with potential predictive factors.

RESULTS

A total of 411 patients were included. The ARR for the 155 relapsing patients had decreased from 2.0 (SD 1.20) the year before treatment to 0.3 (SD 0.31) by year 10 (P < 0.0001). The EDSS score increased from 2.8 (SD 1.44) to 4.8 (SD 1.90) by year 10 (P < 0.0001). A high ARR at MITOX initiation was associated with a longer time to a 1-point increase in EDSS score (hazard ratio, 0.81; 95% confidence interval, 0.67-0.99; P = 0.04). The EDSS score in 256 progressive patients increased from 5.0 (SD 1.33) to 6.5 (SD 1.26) by year 10 (P < 0.0001). We identified four cases of acute myeloid leukemias.

CONCLUSIONS

Patients with the most active forms of MS are the most likely to benefit from MITOX in the long term.

Progressive MS trials: Lessons learned

Up to very recently, no treatments had proved effective in progressive multiple sclerosis (MS). In 2016, four drugs, two tested in phase 3 and two in phase 2 trials, showed a beneficial effect in primary or secondary progressive MS. Although this could indicate a turning point in progressive MS treatment, most of these successes have been modest and mainly restricted to patients with active inflammation, in the context of trials with powerful anti-inflammatory agents. This paper summarises these reasons, particularly focusing on the main lessons learned for the design of future trials. First, a drug's mechanism of action should tackle the specific pathogenic mechanisms that characterise progressive MS. Second, trial populations where new drugs are to be tested should be carefully chosen, possibly including younger patients with shorter disease durations, which have greater chances of showing active deterioration during the trial, therefore increasing the power to detect treatment effects. Third, outcome measures used in future phase 2 and phase 3 trials should be highly sensitive and be accompanied by smart trial designs.

How much progress has there been in the second-line treatment of multiple sclerosis: A 2017 update

In 1993, the US Food and Drug Administration (FDA) approved the first drug specifically for treating multiple sclerosis (MS). More than two decades later, a dozen such treatments are now available. Of these, four are considered second-line treatments for use in escalation strategies and two new drugs are currently undergoing accreditation procedures. Soon, they will provide clinicians with a range of six effective disease-modifying treatments (DMTs) to thwart the inflammatory processes in MS patients with active disease. However, while such a large number of DMTs for MS can help to control early inflammation, any decisions to be made by clinicians have also been made substantially more complex. This complexity is increased by the lack of head-to-head studies comparing these second-line therapies and the benefit-risk profiles for each of these drugs, which are likely to vary among patients. Ultimately, good awareness of the benefits and, more important, the risks of each MS DMT is crucial for the effective management of inflammation in MS.

Mitoxantrone is More Toxic than Doxorubicin in SH-SY5Y Human Cells: A 'Chemobrain' In Vitro Study

The potential neurotoxic effects of anticancer drugs, like doxorubicin (DOX) and mitoxantrone (MTX; also used in multiple sclerosis), are presently important reasons for concern, following epidemiological data indicating that cancer survivors submitted to chemotherapy may suffer cognitive deficits. We evaluated the in vitro neurotoxicity of two commonly used chemotherapeutic drugs, DOX and MTX, and study their underlying mechanisms in the SH-SY5Y human neuronal cell model. Undifferentiated human SH-SY5Y cells were exposed to DOX or MTX (0.13, 0.2 and 0.5 μM) for 48 h and two cytotoxicity assays were performed, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) reduction and the neutral red (NR) incorporation assays. Phase contrast microphotographs, Hoechst, and acridine orange/ethidium bromide stains were performed. Mitochondrial membrane potential was also assessed. Moreover, putative protective drugs, namely the antioxidants N-acetyl-l-cysteine (NAC; 1 mM) and 100 μM tiron, the inhibitor of caspase-3/7, Ac-DEVD-CHO (100 μM), and a protein synthesis inhibitor, cycloheximide (CHX; 10 nM), were tested to prevent DOX- or MTX-induced toxicity. The MTT reduction assay was also done in differentiated SH-SY5Y cells following exposure to 0.2 μM DOX or MTX. MTX was more toxic than DOX in both cytotoxicity assays and according to the morphological analyses. MTX also evoked a higher number of apoptotic nuclei than DOX. Both drugs, at the 0.13 μM concentration, caused mitochondrial membrane potential depolarization after a 48-h exposure. Regarding the putative neuroprotectors, 1 mM NAC was not able to prevent the cytotoxicity caused by either drug. Notwithstanding, 100 μM tiron was capable of partially reverting MTX-induced cytotoxicity in the NR uptake assay. One hundred μM Ac-DEVD-CHO and 10 nM cycloheximide (CHX) also partially prevented the toxicity induced by DOX in the NR uptake assay. MTX was more toxic than DOX in differentiated SH-SY5Y cells, while MTX had similar toxicity in differentiated and undifferentiated SH-SY5Y cells. In fact, MTX was the most neurotoxic drug tested and the mechanisms involved seem dissimilar among drugs. Thus, its toxicity mechanisms need to be further investigated as to determine the putative neurotoxicity for multiple sclerosis and cancer patients.

Early Relapsing Multiple Sclerosis

PURPOSE OF REVIEW

This article provides an evidence-based approach to the management of patients with early relapsing multiple sclerosis (MS).

RECENT FINDINGS

Numerous clinical trials have shown the role of disease-modifying therapies in reducing relapses and new MRI lesions in patients with relapsing MS. Many of these trials also show the ability of these agents to delay disability progression, and a few suggest that disease-modifying therapies may slow brain atrophy in relapsing MS; however, very few suggest that disease-modifying therapies can improve symptoms or disability. The therapeutic armamentarium of disease-modifying therapies includes five interferon formulations, two versions of glatiramer acetate, mitoxantrone, natalizumab, fingolimod, teriflunomide, dimethyl fumarate, and alemtuzumab.

SUMMARY

Although multiple disease-modifying therapies exist, the risks of these vary markedly, head-to-head comparator trials are limited, and no prospective biomarkers for treatment efficacy exist; therefore, choosing a disease-modifying therapy for an individual patient with MS is a difficult decision. This difficulty is compounded by limitations in predicting a patient's disease course, and the risk tolerance of the patient and opinions of the care partner need to be factored into the decision analysis as well. After a disease-modifying therapy is chosen, vigilance for clinical or radiographic breakthrough disease is very important, as this may suggest a suboptimal response to the chosen therapy. Furthermore, the role of symptom management and wellness should always remain part of the approach to the patient with MS.

PIF* promotes brain re-myelination locally while regulating systemic inflammation- clinically relevant multiple sclerosis M.smegmatis model

Neurologic disease diagnosis and treatment is challenging. Multiple Sclerosis (MS) is a demyelinating autoimmune disease with few clinical forms and uncertain etiology. Current studies suggest that it is likely caused by infection(s) triggering a systemic immune response resulting in antigen/non-antigen-related autoimmune response in central nervous system (CNS). New therapeutic approaches are needed. Secreted by viable embryos, PreImplantation Factor (PIF) possesses a local and systemic immunity regulatory role. Synthetic PIF (PIF) duplicates endogenous peptide's protective effect in pre-clinical autoimmune and transplantation models. PIF protects against brain hypoxia-ischemia by directly targeting microglia and neurons. In chronic experimental autoimmune encephalitis (EAE) model PIF reverses paralysis while promoting neural repair. Herein we report that PIF directly promotes brain re-myelination and reverses paralysis in relapsing remitting EAE MS model. PIF crosses the blood-brain barrier targeting microglia. Systemically, PIF decreases pro-inflammatory IL23/IL17 cytokines, while preserving CNS-specific T-cell repertoire. Global brain gene analysis revealed that PIF regulates critical Na⁺/K⁺/Ca⁺⁺ ions, amino acid and glucose transport genes expression. Further, PIF modulates oxidative stress, DNA methylation, cell cycle regulation, and protein ubiquitination while regulating multiple genes. In cultured astrocytes, PIF promotes BDNF-myelin synthesis promoter and SLC2A1 (glucose transport) while reducing deleterious E2F5, and HSP90ab1 (oxidative stress) genes expression. In cultured microglia, PIF increases anti-inflammatory IL10 while reducing pro-inflammatory IFNγ expression. Collectively, PIF promotes brain re-myelination and neuroprotection in relapsing remitting EAE MS model. Coupled with ongoing, Fast-Track FDA approved clinical trial, NCT#02239562 (immune disorder), current data supports PIF's translation for neurodegenerative disorders therapy.

Safety concerns and risk management of multiple sclerosis therapies

Currently, more than ten drugs have been approved for treatment of relapsing-remitting multiple sclerosis (MS). Newer treatments may be more effective, but have less favorable safety record. Interferon-β preparations and glatiramer acetate treatment require frequent subcutaneous or intramuscular injections and are only moderately effective, but have very rarely life-threatening adverse effects, whereas teriflunomide and dimethyl fumarate are administered orally and have equal or better efficacy, but have more potentially severe adverse effects. The highly effective therapies fingolimod, natalizumab, daclizumab, and alemtuzumab have more serious adverse effects, some of which may be life-threatening. The choice between drugs should be based on a benefit-risk evaluation and tailored to the individual patient's requirements in a dialogue between the patient and treating neurologist. Patients with average disease activity can choose between dimethyl fumarate and teriflunomide or the "old injectable." Patients with very active MS may choose a more effective drug as the initial treatment. In case of side effects on one drug, switch to another drug can be tried. Suboptimal effect of the first drug indicates escalation to a highly efficacious drug. A favorable benefit-risk balance can be maintained by appropriate patient selection and appropriate risk management on therapy. New treatments will within the coming 1-2 years change our current treatment algorithm for relapsing-remitting MS.

Association between multiple sclerosis, cancer risk, and immunosuppressant treatment: a cohort study

BACKGROUND

The association between multiple sclerosis (MS) and cancer has long been investigated with conflicting results. Several reports suggest an increased cancer risk among MS patients treated with immunosuppressant (IS) drugs.

METHODS

We performed a cohort study including MS patients recruited at the Neurological Department of the University of Palermo. Mean follow-up period was ten years for the whole cohort. We calculated cancer incidence among patients treated with IS. Incidence rates were compared in the cohort by calculating the relative risk according to length and dose of exposure to IS. Cancer incidence among MS patients was compared to cancer incidence in the general population of Sicily in similar age groups.

RESULTS

On an overall cohort of 531 MS patients (346 women and 185 men) exposed to IS, we estimated a crude incidence rate for cancer of 2.26% (2.02% in women, 2.7% in men). Cancer risk was higher compared to rates observed among an equal number of patients not exposed to IS, and to the risk in the general population in Sicily at similar age groups (adjusted HR: 11.05; CI 1.67-73.3; p = 0.013).

CONCLUSION

The present study showed a higher cancer risk in MS patients associated only to previous IS exposure. Studies on long-term outcomes are essential to evaluate the possibility that treatment options that need to be considered for a long time-period may modify risk for life threatening diseases.

Sex-dependent treatment of chronic EAE with partial MHC class II constructs

Background

One of the main challenges in treating multiple sclerosis (MS) is reversing the effects of accumulated damage in the central nervous system (CNS) of progressive MS subjects. While most of the available drugs for MS subjects are anti-inflammatory and thus are limited to relapsing-remitting MS subjects, it is not clear to what extent their effects are capable of inducing axonal repair and remyelination in subjects with chronic MS.

Methods

A chronic model of experimental autoimmune encephalomyelitis (EAE) was used to evaluate the potency of partial MHC (pMHC) class II constructs in treating progressive EAE.

Results

We demonstrated an estrogen receptor alpha (ERα)-dependent increased dose requirement for effective treatment of female vs. male mice using pMHC. Such treatment using 100-μg doses of RTL342M or DRα1-mMOG-35-55 constructs significantly reversed clinical severity and showed a clear trend for inhibiting ongoing CNS damage, demyelination, and infiltration of inflammatory cells into the CNS in male mice. In contrast, WT female mice required larger 1-mg doses for effective treatment, although lower 100-μg doses were effective in ovariectomized or ERα-deficient mice with EAE.

Conclusions

These findings will assist in the design of future clinical trials using pMHC for treatment of progressive MS.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-017-0873-y) contains supplementary material, which is available to authorized users.

Optimization and stratification of multiple sclerosis treatment in fast developing economic countries: a perspective from Qatar

OBJECTIVE

The introduction of disease-modifying therapies (DMTs) - with varying degrees of efficacy for reducing annual relapse rate and disability progression - has considerably transformed the therapeutic landscape of relapsing-remitting multiple sclerosis (RRMS). We aim to develop rational evidence-based treatment recommendations and algorithms for the management of clinically isolated syndrome (CIS) and RRMS that conform to the healthcare system in a fast-developing economic country such as Qatar.

RESEARCH DESIGN AND METHODS

We conducted a systematic review using a comprehensive search of MEDLINE, PubMed, and Cochrane Database of Systematic Reviews (1 January 1990 through 30 September 2016). Additional searches of the American Academy of Neurology and European Committee for Treatment and Research in Multiple Sclerosis abstracts from 2012 through 2016 were performed, in addition to searches of the Food and Drug Administration and European Medicines Agency websites to obtain relevant safety information on these DMTs.

RESULTS

For each of the DMTs, the mode of action, efficacy, safety and tolerability are briefly discussed. To facilitate the interpretation, the efficacy data of the pivotal phase III trials are expressed by their most clinically useful measure of therapeutic efficacy, the number needed to treat (NNT). In addition, an overview of head-to-head trials in RRMS is provided as well as a summary of the several different RRMS management strategies (lateral switching, escalation, induction, maintenance and combination therapy) and the potential role of each DMT. Finally, algorithms were developed for CIS, active and highly active or rapidly evolving RRMS and subsequent breakthrough disease or suboptimal treatment response while on DMTs. The benefit-to-risk profiles of the DMTs, taking into account patient preference, allowed the provision of rational and safe patient-tailored treatment algorithms.

CONCLUSIONS

Recommendations and algorithms for the management of CIS and RRMS have been developed relevant to the healthcare system of this fast-developing economic country.

Celastrol Attenuates Multiple Sclerosis and Optic Neuritis in an Experimental Autoimmune Encephalomyelitis Model

This study was aimed to evaluate the effects of celastrol, a natural compound with multiple bioactivities, on multiple sclerosis and optic neuritis (ON) in rat experimental autoimmune encephalomyelitis (EAE). EAE was induced in Sprague Dawley rats using myelin basic protein, and the animals received daily intraperitoneal injections of celastrol or vehicle for 13 days. The EAE rats showed abnormal neurobehavior and inflammatory infiltration and demyelination in the spinal cord. Significantly upregulated mRNA expression of pro-inflammatory cytokines interferon-γ and interleukin-17 and downregulated anti-inflammatory cytokines interleukin-4 were found in the spinal cord of EAE rats. In the study of ON, severely inflammatory responses like in the spinal cord were also seen in the optic nerve, as well as obvious microgliosis. Furthermore, activation of nuclear factor kappa-B and upregulated inducible nitric oxide synthase was observed in the optic nerve. In addition, apoptosis of retinal ganglion cells and dysregulation of apoptotic-associated proteins in the optic nerve were found in EAE rats. Treatment of celastrol potently restored these changes. In most of the indexes, the effects of high dose of celastrol were better than the low dose. Our data conclude that administration of celastrol attenuates multiple sclerosis and ON in EAE via anti-inflammatory and anti-apoptotic effects. These findings provide new pre-clinical evidence for the use of celastrol in treatment of multiple sclerosis.

Altered blood-brain barrier transport in neuro-inflammatory disorders

During neurodegenerative and neuroinflammatory disorders of the central nervous system (CNS), such as Alzheimer's disease (AD) and multiple sclerosis (MS), the protective function of the blood-brain barrier (BBB) may be severely impaired. The general neuro-inflammatory response, ranging from activation of glial cells to immune cell infiltration that is frequently associated with such brain diseases may underlie the loss of the integrity and function of the BBB. Consequentially, the delivery and disposition of drugs to the brain will be altered and may influence the treatment efficiency of such diseases. Altered BBB transport of drugs into the CNS during diseases may be the result of changes in both specific transport and non-specific transport pathways. Potential alterations in transport routes like adsorptive mediated endocytosis and receptor-mediated endocytosis may affect drug delivery to the brain. As such, drugs that normally are unable to traverse the BBB may reach their target in the diseased brain due to increased permeability. In contrast, the delivery of (targeted) drugs could be hampered during inflammatory conditions due to disturbed transport mechanisms. Therefore, the inventory of the neuro-inflammatory status of the neurovasculature (or recovery thereof) is of utmost importance in choosing and designing an adequate drug targeting strategy under disease conditions. Within this review we will briefly discuss how the function of the BBB can be affected during disease and how this may influence the delivery of drugs into the diseased CNS.

The usefulness of immunotherapy in pediatric neurodegenerative disorders: A systematic review of literature data

Immunotherapeutic strategies to treat neurodegenerative disorders have inspired the scientific community. The aim of our review is to address the translational aspects of neuroimmunology to describe the efficacy of immunotherapy in the treatment of pediatric neurodegenerative disorders. In the studies we analyzed IVIG were found to be efficient in the treatment of post-streptococcal neurodegenerative disorders, even if in PANDAS, plasma-exchange (PE) showed a higher efficiency. IVIG were also successfully used in ADEM and Guillan-Barré syndrome. In Sydenham Chorea the use of methylprednisolone was found in most cases as efficient as IVIG, while in Tourette's Syndrome, Colecoxib was successfully used in one patient. Pediatric Multiple Sclerosis seems to respond better to immunosuppressant agents (Mitoxantrone, Cyclophosphamide, Natalizumab), as well as Neuromyelitis optica (Rituximab, Mycofenolate). The importance of this review relies in the attempt to draw standardized guidelines for immunotherapy in pediatric neurodegeneratve disorders.

Considerations on long-term immuno-intervention in the treatment of multiple sclerosis: an expert opinion

INTRODUCTION

As management of multiple sclerosis (MS) requires life-long treatment with disease-modifying agents, any risks associated with long-term use should be considered when evaluating therapeutic options.

AREAS COVERED

Immune cells of the innate and adaptive immune systems play various roles in the pathogenesis of MS. MS therapies affect the immune system, each with a unique mode of action, and consequently possess different long-term safety profiles. Rare, but serious safety concerns, including an increased risk of infection and cancer, have been associated with immunosuppressant use. The risks associated with newer immunosuppressive agents, which target specific elements of MS disease pathophysiology, are not yet fully established as the duration of clinical trials is relatively short and post-marketing experience is limited. Non-immunosuppressants used to treat MS have well-defined safety profiles established over a large number of patient-years demonstrating them to be well-tolerated long-term treatment options. When considering the long-term use of disease-modifying agents for treating MS, classification as immunosuppressants or non-immunosuppressants can be useful when evaluating potential risks associated with chronic use.

EXPERT OPINION

A successful therapeutic strategy for any serious, chronic disease such as MS should weigh effectiveness versus long-term safety of available treatments.

The Use of Oral Disease-Modifying Therapies in Multiple Sclerosis

Three oral disease-modifying drugs-fingolimod, teriflunomide, and dimethyl fumarate (DMF)-are available for treatment of relapsing forms of multiple sclerosis (MS). All three agents were approved in the last decade, primarily on the basis of a moderate to substantial reduction in the occurrence of MS relapses and central nervous system lesion formation detected by MRI. In the trials leading to approval, the first oral disease-modifying drug, fingolimod, reduced the annualized relapse rate (ARR) from 0.40 in placebo-treated patients to 0.18 (FREEDOMS) and from 0.33 in patients treated with interferon β1a intramuscularly to 0.16 (TRANSFORMS). Teriflunomide, approved on the basis of the two placebo-controlled trials TEMSO and TOWER, demonstrated a reduction in the ARR from 0.54 to 0.37 and from 0.50 to 0.32 respectively. The latest oral MS medication, approved in 2014, is DMF, which had been used in a different formulation for treatment of psoriasis for decades. In the 2-year DEFINE study, the proportion of patients with a relapse was reduced to 27 %, compared with 46 % in placebo arm, whereas in the CONFIRM trial, the ARR was reduced from 0.40 (placebo) to 0.22 in the DMF-treated group of patients. In this review, we will elucidate the mechanisms of action of these three medications and compare their efficacy, safety, and tolerability as a practical guideline for their use. We will further discuss effects other than relapse reduction these small molecules may exert, including potential activities within the central nervous system, and briefly summarize emerging data on new oral MS drugs in clinical development.