Improvement in disability after alemtuzumab treatment of multiple sclerosis is associated with neuroprotective autoimmunity

Clinical relevance of thymic and bone marrow outputs in multiple sclerosis patients treated with alemtuzumab

Thymic and bone marrow outputs were evaluated in 13 sequential samples of 68 multiple sclerosis patients who initiated alemtuzumab and were clinically followed for 48 months. Three months after alemtuzumab infusions, the levels of new T lymphocytes were significantly reduced, but progressively increased reaching the highest values at 36 months, indicating the remarkable capacity of thymic function recovery. Newly produced B cells exceeded baseline levels as early as 3 months after alemtuzumab initiation. Heterogeneous patterns of new T- and B-cell recovery were identified, but without associations with age, sex, previous therapies, development of secondary autoimmunity or infections, and disease re-emergence. Trial registration version 2.0-27/01/2016.

Biochemical biomarkers for multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is the most frequent demyelinating disease of the central nervous system. Although there is currently no definite cure for MS, new therapies have recently been developed based on a continuous search for new biomarkers.

DEVELOPMENT

MS diagnosis relies on the integration of clinical, imaging and laboratory findings as there is still no singlepathognomonicclinical feature or diagnostic laboratory biomarker. The most commonly laboratory test used is the presence of immunoglobulin G oligoclonal bands (OCB) in cerebrospinal fluid of MS patients. This test is now included in the 2017 McDonald criteria as a biomarker of dissemination in time. Nevertheless, there are other biomarkers currently in use such as kappa free light chain, which has shown higher sensitivity and specificity for MS diagnosis than OCB. In addition, other potential laboratory tests involved in neuronal damage, demyelination and/or inflammation could be used for detecting MS.

CONCLUSIONS

CSF and serum biomarkers have been reviewed for their use in MS diagnosis and prognosis to stablish an accurate and prompt MS diagnosis, crucial to implement an adequate treatment and to optimize clinical outcomes over time.

Longitudinal assessment of neurocognitive function in people with relapsing multiple sclerosis initiating alemtuzumab in routine clinical practice: LEM-COG study results

BACKGROUND

Alemtuzumab is effective in reducing relapse rate and disability, but limited data exist on its effect on cognitive function in relapsing multiple sclerosis (RMS). The present study assessed neurocognitive function and safety associated with alemtuzumab treatment in RMS.

METHODS

This longitudinal, single-arm, prospective study included people with RMS (aged 25-55 years) who were treated with alemtuzumab in clinical practice in the United States of America and Canada. The first participant was enrolled in December 2016. The primary endpoint was the change from baseline to post-baseline (month [M] 12/24) in MS-COGnitive (MS-COG) composite score. Secondary endpoints included Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Brief Visuospatial Memory Test-Revised (BVMT-R), Selective Reminding Test (SRT), Controlled Oral Word Association Test (COWAT), and Automated Neuropsychological Assessment Metrics (ANAM) scores. Depression and fatigue were assessed using Hamilton Rating Scale-Depression (HAM-D) and Fatigue Severity Scale (FSS)/Modified Fatigue Impact Scale (MFIS), respectively. Magnetic resonance imaging (MRI) parameters were assessed when available. Safety was assessed throughout the study. Descriptive statistics were used for the pre-specified statistical analyses. Since the study was terminated early (November 2019) because of operational and resource difficulties, post hoc analyses for statistical inference were performed among participants who had a baseline value and at least one complete post-baseline assessment for cognitive parameters, fatigue, or depression.

RESULTS

Of the 112 participants enrolled, 39 were considered as the primary analysis population at M12. At M12, a mean change of 0.25 (95% confidence interval [CI]: 0.04, 0.45; p = 0.0049; effect size [ES]: 0.39) was observed in the MS-COG composite score. Improvements were observed in processing speed (based on PASAT and SDMT; p < 0.0001; ES: 0.62), as well as in individual PASAT, SDMT and COWAT scores. An improvement was also noted in HAM-D (p = 0.0054; ES: -0.44), but not in fatigue scores. Among MRI parameters, decreases in burden of disease volume (BDV; ES: -0.12), new gadolinium-enhancing lesions (ES: -0.41) and newly active lesions (ES: -0.07) were observed at M12. About 92% of participants showed stable or improved cognitive status at M12. There were no new safety signals reported in the study. The most common adverse events (≥10% of participants) were headache, fatigue, nausea, insomnia, urinary tract infection, pain in extremity, chest discomfort, anxiety, dizziness, arthralgia, flushing, and rash. Hypothyroidism (3.7%) was the most frequent adverse event of special interest.

CONCLUSION

The findings from this study suggest that alemtuzumab has a positive impact on cognitive function with significant improvements in processing speed and depression in people with RMS over a period of 12 months. The safety profile of alemtuzumab was consistent with previous studies.

Acquired immunity and Alzheimer's disease

Alzheimer's disease (AD) is an age-related neurodegenerative disease characterized by progressive cognitive defects. The role of the central immune system dominated by microglia in the progression of AD has been extensively investigated. However, little is known about the peripheral immune system in AD pathogenesis. Recently, with the discovery of the meningeal lymphatic vessels and glymphatic system, the roles of the acquired immunity in the maintenance of central homeostasis and neurodegenerative diseases have attracted an increasing attention. The T cells not only regulate the function of neurons, astrocytes, microglia, oligodendrocytes and brain microvascular endothelial cells, but also participate in the clearance of β-amyloid (Aβ) plaques. Apart from producing antibodies to bind Aβ peptides, the B cells affect Aβ-related cascades via a variety of antibody-independent mechanisms. This review systemically summarizes the recent progress in understanding pathophysiological roles of the T cells and B cells in AD.

The role of the adaptive immune system and T cell dysfunction in neurodegenerative diseases

The adaptive immune system and associated inflammation are vital in surveillance and host protection against internal and external threats, but can secondarily damage host tissues. The central nervous system is immune-privileged and largely protected from the circulating inflammatory pathways. However, T cell involvement and the disruption of the blood-brain barriers have been linked to several neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Under normal physiological conditions, regulatory T cells (Treg cells) dampen the inflammatory response of effector T cells. In the pathological states of many neurodegenerative disorders, the ability of Treg cells to mitigate inflammation is reduced, and a pro-inflammatory environment persists. This perspective review provides current knowledge on the roles of T cell subsets (e.g., effector T cells, Treg cells) in neurodegenerative and ocular diseases, including uveitis, diabetic retinopathy, age-related macular degeneration, and glaucoma. Many neurodegenerative and ocular diseases have been linked to immune dysregulation, but the cellular events and molecular mechanisms involved in such processes remain largely unknown. Moreover, the role of T cells in ocular pathologies remains poorly defined and limited literature is available in this area of research. Adoptive transfer of Treg cells appears to be a vital immunological approach to control ocular pathologies. Similarities in T cell dysfunction seen among non-ocular neurodegenerative diseases suggest that this area of research has a great potential to develop better therapeutic agents for ocular diseases and warrants further studies. Overall, this perspective review article provides significant information on the roles of T cells in numerous ocular and non-ocular neurodegenerative diseases.

The genealogy, methodology, similarities and differences of immune reconstitution therapies for multiple sclerosis and neuromyelitis optica

Immune reconstitution therapies (IRTs) are a type of short course procedure or pharmaceutical agent within the MS pharmacopeia. They emanate from oncology and induce transient incomplete lympho-ablation with or without myelo-ablation, resulting in potential prolonged immunomodulation. Thus, they provide significant prophylaxis from disease activity without retreatment. Modern IRT for autoimmunity encompasses a heterogeneous group of pulsed lympho- and non-myelo-ablative treatments designed to re-boot the adaptive immune system in a quasi-permanent manner - a re-induction of ontogeny. IRT is the extensive debulking of an auto-aggressive immune system to attempt to reach the Holy Grail of immune tolerance. This incomplete yet significant lympho-ablation induces lymphoproliferation, reduces pathogenic clonal cells, causes thymopoiesis and results in the induction of immune tolerance. Lympho-ablation with immune reconstitution can result in minimal residual autoimmunity. There is a resetting of the immune thermostat - i.e., the immunostat. IRTs have the potential to provide prolonged periods of disease inactivity without retreatment in part through the immunological results of their pulsatile lymphocyte depletion. It is vital to increase our understanding of how IRTs alter a patient's immune response to the antigenic target of the disease so that we can devise newer, more durable and safer forms of such agents. What common features do extant IRTs (i.e., stem cell transplant, alemtuzumab and oral cladribine) have to produce the durable therapeutic response without long term treatment in neuroimmunological diseases such as MS (multiple sclerosis) and NMOSD (neuromyelitis optica spectrum disorders)? Can we learn from these critical features to predict what other maneuvers or agents might effect similar clinical results with equal or greater efficacy and safety?

Treatment With CD52 Antibody Protects Neurons in Experimental Autoimmune Encephalomyelitis Mice During the Recovering Phase

Multiple sclerosis (MS) is a chronic autoimmune disease driven by T and B lymphocytes. The remyelination failure and neurodegeneration results in permanent clinical disability in MS patients. A desirable therapy should not only modulate the immune system, but also promote neuroprotection and remyelination. To investigate the neuroprotective effect of CD52 antibody in MS, both C57BL/6J and SJL mice with experimental autoimmune encephalomyelitis (EAE) were treated with CD52 antibody at the peak of disease. Treatment with CD52 antibody depleted T but not B lymphocytes in the blood, reduced the infiltration of T lymphocytes and microglia/macrophages in the spinal cord. Anti-CD52 therapy attenuated EAE scores during the recovery phase. It protected neurons immediately after treatment (within 4 days) as shown by reducing the accumulation of amyloid precursor proteins. It potentially promoted remyelination as it increased the number of olig2/CC-1-positive mature oligodendrocytes and prevented myelin loss in the following days (e.g., 14 days post treatment). In further experiments, EAE mice with a conditional knockout of BDNF in neurons were administered with CD52 antibodies. Neuronal deficiency of BDNF attenuated the effect of anti-CD52 treatment on reducing EAE scores and inflammatory infiltration but did not affect anti-CD52 treatment-induced improvement of myelin coverage in the spinal cord. In summary, anti-CD52 therapy depletes CD4-positive T lymphocytes, prevents myelin loss and protects neurons in EAE mice. Neuronal BDNF regulates neuroprotective and anti-inflammatory effect of CD52 antibody in EAE mice.

Immune Regulatory Cell Bias Following Alemtuzumab Treatment in Relapsing-Remitting Multiple Sclerosis

Alemtuzumab is a highly effective treatment for relapsing-remitting multiple sclerosis. It selectively targets the CD52 antigen to induce profound lymphocyte depletion, followed by recovery of T and B cells with regulatory phenotypes. We previously showed that regulatory T cell function is restored with cellular repletion, but little is known about the functional capacity of regulatory B-cells and peripheral blood monocytes during the repletion phase. In this study (ClinicalTrials.gov ID# NCT03647722) we simultaneously analyzed the change in composition and function of both regulatory lymphocyte populations and distinct monocyte subsets in cross-sectional cohorts of MS patients prior to or 6, 12, 18, 24 or 36 months after their first course of alemtuzumab treatment. We found that the absolute number and percentage of cells with a regulatory B cell phenotype were significantly higher after treatment and were positivity correlated with regulatory T cells. In addition, B cells from treated patients secreted higher levels of IL-10 and BDNF, and inhibited the proliferation of autologous CD4⁺CD25^- T cell targets. Though there was little change in monocytes populations overall, following the second annual course of treatment, CD14⁺ monocytes had a significantly increased anti-inflammatory bias in cytokine secretion patterns. These results confirmed that the immune system in alemtuzumab-treated patients is altered in favor of a regulatory milieu that involves expansion and increased functionality of multiple regulatory populations including B cells, T cells and monocytes. Here, we showed for the first time that functionally competent regulatory B cells re-appear with similar kinetics to that of regulatory T-cells, whereas the change in anti-inflammatory bias of monocytes does not occur until after the second treatment course. These findings justify future studies of all regulatory cell types following alemtuzumab treatment to reveal further insights into mechanisms of drug action, and to identify key immunological predictors of durable clinical efficacy in alemtuzumab-treated patients.

Anti-CD52 Therapy for Multiple Sclerosis: An Update in the COVID Era

CD52 is a small surface glycoprotein composed of 12 amino acids. CD52 is found mostly on the surface of mature immune cells, such as lymphocytes, monocytes, eosinophils, and dendritic cells, as well as the male genital tract: within the epididymis and on the surface of mature sperm. Low CD52 expression is also found in neutrophils. CD52 function is not fully understood, although experiments with anti-CD52 antibodies have shown that CD52 is essential for lymphocyte transendothelial migration and may contribute to costimulation of CD4⁺ T cells and T-cell activation and proliferation. Although knowledge about exact CD52 function is still poor, CD52 presence on the surface of a broad spectrum of immune cells makes it a therapeutic target, especially in immunomediated diseases, such as multiple sclerosis. In multiple sclerosis, alemtuzumab is registered for adult patients with the relapsing–remitting form of the disease defined by clinical and imaging features. Despite the high efficacy of the drug, the main issue is its safety. The main adverse effects of alemtuzumab are associated with drug infusion due to cytokine release and cytotoxic effects of antibodies associated with lymphocyte depletion, which leads to immunosuppression, and secondary autoimmunity that may be the effect of excessive B-cell repopulation and cancer. This review presents current knowledge on the drug’s mechanism of action, efficacy and safety data from clinical trials, and real-world observations, including available though scarce data on using alemtuzumab in the COVID era.

B cells in multiple sclerosis - from targeted depletion to immune reconstitution therapies

Increasing evidence indicates the involvement of B cells in the pathogenesis of multiple sclerosis (MS), but their precise roles are unclear. In this Review, we provide an overview of the development and physiological functions of B cells and the main mechanisms through which B cells are thought to contribute to CNS autoimmunity. In MS, abnormalities of B cell function include pro-inflammatory cytokine production, defective B cell regulatory function and the formation of tertiary lymphoid-like structures in the CNS, which are the likely source of abnormal immunoglobulin production detectable in the cerebrospinal fluid. We also consider the hypothesis that Epstein-Barr virus (EBV) is involved in the B cell overactivation that leads to inflammatory injury to the CNS in MS. We also review the immunological effects - with a focus on the effects on B cell subsets - of several successful therapeutic approaches in MS, including agents that selectively deplete B cells (rituximab, ocrelizumab and ofatumumab), agents that less specifically deplete lymphocytes (alemtuzumab and cladribine) and autologous haematopoietic stem cell transplantation, in which the immune system is unselectively ablated and reconstituted. We consider the insights that these effects on B cell populations provide and their potential to further our understanding and targeting of B cells in MS.

Confirmed 6-Month Disability Improvement and Worsening Correlate with Long-term Disability Outcomes in Alemtuzumab-Treated Patients with Multiple Sclerosis: Post Hoc Analysis of the CARE-MS Studies

Introduction

In the 2-year CARE-MS trials (NCT00530348; NCT00548405) in patients with relapsing–remitting multiple sclerosis, alemtuzumab showed superior efficacy versus subcutaneous interferon beta-1a. Efficacy was maintained in two consecutive extensions (NCT00930553; NCT02255656). This post hoc analysis compared disability outcomes over 9 years among alemtuzumab-treated patients according to whether they experienced confirmed disability improvement (CDI) or worsening (CDW) or neither CDI nor CDW.

Methods

CARE-MS patients were randomized to receive two alemtuzumab courses (12 mg/day; 5 days at baseline; 3 days at 12 months), with additional as-needed 3-day courses in the extensions. CDI or CDW were defined as ≥ 1.0-point decrease or increase, respectively, in Expanded Disability Status Scale (EDSS) score from core study baseline confirmed over 6 months, assessed in patients with baseline EDSS score ≥ 2.0. Improved or stable EDSS scores were defined as ≥ 1-point decrease or ≤ 0.5-point change (either direction), respectively, from core study baseline. Functional systems (FS) scores were also assessed.

Results

Of 511 eligible patients, 43% experienced CDI and 34% experienced CDW at any time through year 9 (patients experiencing both CDI and CDW were counted in each individual group); 29% experienced neither CDI nor CDW. At year 9, patients with CDI had a −0.58-point mean EDSS score change from baseline; 88% had stable or improved EDSS scores. Improvements occurred across all FS, primarily in sensory, pyramidal, and cerebellar domains. Patients with CDW had a +1.71-point mean EDSS score change; 16% had stable or improved EDSS scores. Patients with neither CDI nor CDW had a −0.10-point mean EDSS score change; 98% had stable or improved EDSS scores.

Conclusion

CDI achievement at any point during the CARE-MS studies was associated with improved disability at year 9, highlighting the potential of alemtuzumab to change the multiple sclerosis course. Conversely, CDW at any point was associated with worsened disability at year 9.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00262-3.

Reviewing the Clinical Implications of Treating Narcolepsy as an Autoimmune Disorder

Narcolepsy type 1 (NT1) is a lifelong sleep disorder, primarily characterized clinically by excessive daytime sleepiness and cataplexy and pathologically by the loss of hypocretinergic neurons in the lateral hypothalamus. Despite being a rare disorder, the NT1-related burden for patients and society is relevant due to the early onset and chronic nature of this condition. Although the etiology of narcolepsy is still unknown, mounting evidence supports a central role of autoimmunity. To date, no cure is available for this disorder and current treatment is symptomatic. Based on the hypothesis of the autoimmune etiology of this disease, immunotherapy could possibly represent a valid therapeutic option. However, contrasting and limited results have been provided so far. This review discusses the evidence supporting the use of immunotherapy in narcolepsy, the outcomes obtained so far, current issues and future directions.

Protective role of anticancer drugs in neurodegenerative disorders: A drug repurposing approach

The disease heterogeneity and little therapeutic progress in neurodegenerative diseases justify the need for novel and effective drug discovery approaches. Drug repurposing is an emerging approach that reinvigorates the classical drug discovery method by divulging new therapeutic uses of existing drugs. The common biological background and inverse tuning between cancer and neurodegeneration give weight to the conceptualization of repurposing of anticancer drugs as novel therapeutics. Many studies are available in the literature, which highlights the success story of anticancer drugs as repurposed therapeutics. Among them, kinase inhibitors, developed for various oncology indications evinced notable neuroprotective effects in neurodegenerative diseases. In this review, we shed light on the salient role of multiple protein kinases in neurodegenerative disorders. We also proposed a feasible explanation of the action of kinase inhibitors in neurodegenerative disorders with more attention towards neurodegenerative disorders. The problem of neurotoxicity associated with some anticancer drugs is also highlighted. Our review encourages further research to better encode the hidden potential of anticancer drugs with the aim of developing prospective repurposed drugs with no toxicity for neurodegenerative disorders.

Early Diagnosis of Multiple Sclerosis Based on Optical and Electrochemical Biosensors: Comprehensive Perspective

Background:

Multiple Sclerosis (MS) involves an immune-mediated response in which body’s immune system destructs the protective sheath (myelin). Part of the known MS biomarkers are discovered in cerebrospinal fluid like oligoclonal lgG (OCGB), and also in blood like myelin Oligodendrocyte Glycoprotein (MOG). The conventional MS diagnostic methods often fail to detect the disease in early stages such as Clinically Isolated Syndrome (CIS), which considered as a concerning issue since CIS highlighted as a prognostic factor of MS development in most cases.

Methods:

MS diagnostic techniques include Magnetic Resonance Imaging (MRI) of the brain and spinal cord, lumbar puncture (or spinal tap) that evaluate cerebrospinal fluid, evoked potential testing revealing abnormalities in the brain and spinal cord. These conventional diagnostic methods have some negative points such as extensive processing time as well as restriction in the quantity of samples that can be analyzed concurrently. Scientists have focused on developing the detection methods especially early detection which belongs to ultra-sensitive, non-invasive and needed for the Point of Care (POC) diagnosis because the situation was complicated by false positive or negative results.

Results:

As a result, biosensors are utilized and investigated since they could be ultra-sensitive to specific compounds, cost effective devices, body-friendly and easy to implement. In addition, it has been proved that the biosensors on physiological fluids (blood, serum, urine, saliva, milk etc.) have quick response in a non-invasive rout. In general form, a biosensor system for diagnosis and early detection process usually involves; biomarker (target molecule), bio receptor (recognition element) and compatible bio transducer.

Conclusion:

Studies underlined that early treatment of patients with high possibility of MS can be advantageous by postponing further abnormalities on MRI and subsequent attacks.

:

This Review highlights variable disease diagnosis approaches such as Surface Plasmon Resonance (SPR), electrochemical biosensors, Microarrays and microbeads based Microarrays, which are considered as promising methods for detection and early detection of MS.

Long-term efficacy and safety of alemtuzumab in patients with RRMS: 12-year follow-up of CAMMS223

BACKGROUND

In the phase 2 CAMMS223 trial (NCT00050778), alemtuzumab significantly improved clinical and MRI outcomes versus subcutaneous interferon beta-1a over 3 years in treatment-naive patients with relapsing-remitting MS. Here, we assess efficacy and safety of alemtuzumab over 12 years in CAMMS223 patients who enrolled in the CAMMS03409 extension (NCT00930553), with available follow-up through the subsequent TOPAZ extension (NCT02255656).

METHODS

In CAMMS223, patients received 2 alemtuzumab courses (12 mg/day; baseline: 5 days; 12 months later: 3 days); 22% received a third course. In the open-label, nonrandomized extensions, patients could receive as-needed additional alemtuzumab or other disease-modifying therapies.

RESULTS

Of 108 alemtuzumab-treated patients in CAMMS223, 60 entered the CAMMS03409 extension; 33% received a total of 2 alemtuzumab courses, and 73% received no more than 3 courses through Year 12. Over 12 years, annualized relapse rate was 0.09, 71% of patients had stable or improved Expanded Disability Status Scale scores, and 69% were free of 6-month confirmed disability worsening. In Year 12, 73% of patients were free of MRI disease activity. Cumulatively throughout the extensions (Years 7-12), 34% of patients had no evidence of disease activity. Adverse event (AE) incidence declined through Year 12. Infusion-associated reactions peaked at first course and declined thereafter. Cumulative thyroid AE incidence was 50%; one immune thrombocytopenia event occurred, and there were no autoimmune nephropathy cases.

CONCLUSIONS

Alemtuzumab efficacy was maintained over 12 years in CAMMS223 patients, with 73% receiving no more than three courses. The safety profile in this cohort was consistent with other alemtuzumab clinical trials.

Repopulation of T, B, and NK cells following alemtuzumab treatment in relapsing-remitting multiple sclerosis

OBJECTIVE

To characterize long-term repopulation of peripheral immune cells following alemtuzumab-induced lymphopenia in relapsing-remitting MS (RRMS), with a focus on regulatory cell types, and to explore associations with clinical outcome measures.

METHODS

The project was designed as a multicenter add-on longitudinal mechanistic study for RRMS patients enrolled in CARE-MS II, CARE-MS II extension at the University of Southern California and Stanford University, and an investigator-initiated study conducted at the Universities of British Columbia and Chicago. Methods involved collection of blood at baseline, prior to alemtuzumab administration, and at months 5, 11, 17, 23, 36, and 48 post-treatment. T cell, B cell, and natural killer (NK) cell subsets, chemokine receptor expression in T cells, in vitro cytokine secretion patterns, and regulatory T cell (Treg) function were assessed. Clinical outcomes, including expanded disability status score (EDSS), relapses, conventional magnetic resonance imaging (MRI) measures, and incidents of secondary autoimmunity were tracked.

RESULTS

Variable shifts in lymphocyte populations occurred over time in favor of CD4+ T cells, B cells, and NK cells with surface phenotypes characteristic of regulatory subsets, accompanied by reduced ratios of effector to regulatory cell types. Evidence of increased Treg competence was observed after each treatment course. CD4+ and CD8+ T cells that express CXCR3 and CCR5 and CD8+ T cells that express CDR3 and CCR4 were also enriched after treatment, indicating heightened trafficking potential in activated T cells. Patterns of repopulation were not associated with measures of clinical efficacy or secondary autoimmunity, but exploratory analyses using a random generalized estimating equation (GEE) Poisson model provide preliminary evidence of associations between pro-inflammatory cell types and increased risk for gadolinium (Gd+) enhancing lesions, while regulatory subsets were associated with reduced risk. In addition, the risk for T2 lesions correlated with increases in CD3+CD8+CXCR3+ cells.

CONCLUSIONS

Lymphocyte repopulation after alemtuzumab treatment favors regulatory subsets in the T cell, B cell, and NK cell compartments. Clinical efficacy may reflect the sum of interactions among them, leading to control of potentially pathogenic effector cell types. Several immune measures were identified as possible biomarkers of lesion activity. Future studies are necessary to more precisely define regulatory and effector subsets and their contributions to clinical efficacy and risk for secondary autoimmunity in alemtuzumab-treated patients, and to reveal new insights into mechanisms of immunopathogenesis in MS.

TRIAL REGISTRATION

Parent trials for this study are registered with ClinicalTrials.gov: CARE-MS II: NCT00548405, CARE-MS II extension: NCT00930553 and ISS: NCT01307332.

Anti-CD52 blocks EAE independent of PD-1 signals and promotes repopulation dominated by double-negative T cells and newly generated T and B cells

Lymphocyte depletion using anti-CD52 antibody effectively reduces relapses of multiple sclerosis (MS). To begin to understand what mechanisms might control this outcome, we examined the effect of a murine-CD52-specific mAb on the depletion and repopulation of immune cells in mice with experimental autoimmune encephalomyelitis (EAE), a model of MS. We tested whether the tolerance-promoting receptor programmed cell death protein-1 (PD-1) is required for disease remission post anti-CD52, and found that PD-1-deficient mice with a more severe EAE were nevertheless effectively treated with anti-CD52. Anti-CD52 increased the proportions of newly generated T cells and double-negative (DN) T cells while reducing newly generated B cells; the latter effect being associated with a higher expression of CD52 by these cells. In the longer term, anti-CD52 caused substantial increases in the proportion of newly generated lymphocytes and DN T cells in mice with EAE. Thus, the rapid repopulation of lymphocytes from central lymphoid organs post anti-CD52 may limit further disease. Furthermore, these data identify DN T cells, a subset with immunoregulatory potential, as a significant hyperrepopulating subset following CD52-mediated depletion.

Microglia in Multiple Sclerosis: Friend or Foe?

Microglia originate from myeloid progenitors in the embryonic yolk sac and play an integral role in central nervous system (CNS) development, immune surveillance and repair. The role of microglia in multiple sclerosis (MS) has been complex and controversial, with evidence suggesting that these cells play key roles in both active inflammation and remyelination. Here we will review the most recent histological classification of MS lesions as well as the evidence supporting both inflammatory and reparative functions of these cells. We will also review how microglia may yield new biomarkers for MS activity and serve as a potential target for therapy.

Established and Emerging Immunological Complications of Biological Therapeutics in Multiple Sclerosis

Biologic immunotherapies have transformed the treatment landscape of multiple sclerosis. Such therapies include recombinant proteins (interferon beta), as well as monoclonal antibodies (natalizumab, alemtuzumab, daclizumab, rituximab and ocrelizumab). Monoclonal antibodies show particular efficacy in the treatment of the inflammatory phase of multiple sclerosis. However, the immunological perturbations caused by biologic therapies are associated with significant immunological adverse reactions. These include development of neutralising immunogenicity, secondary immunodeficiency and secondary autoimmunity. These complications can affect the balance of risks and benefits of biologic agents, and 2018 saw the withdrawal from the market of daclizumab, an anti-CD25 monoclonal antibody, due to concerns about the development of severe, unpredictable autoimmunity. Here we review established and emerging risks associated with multiple sclerosis biologic agents, with an emphasis on their immunological adverse effects. We also discuss the specific challenges that multiple sclerosis biologics pose to drug safety systems, and the potential for improvements in safety frameworks.

Targeting CD52 does not affect murine neuron and microglia function

The humanized anti-CD52 antibody alemtuzumab is successfully used in the treatment of multiple sclerosis (MS) and is thought to exert most of its therapeutic action by depletion and repopulation of mainly B and T lymphocytes. Although neuroprotective effects of alemtuzumab have been suggested, direct effects of anti-CD52 treatment on glial cells and neurons within the CNS itself have not been investigated so far. Here, we show CD52 expression in murine neurons, astrocytes and microglia, both in vitro and in vivo. As expected, anti CD52-treatment caused profound lymphopenia and improved disease symptoms in mice subjected to experimental autoimmune encephalomyelitis (EAE). CD52 blockade also had a significant effect on microglial morphology in organotypic hippocampal slice cultures but did not affect microglial functions. Furthermore, anti-CD52 neither changed baseline neuronal calcium, nor did it act neuroprotective in excitotoxicity models. Altogether, our findings argue against a functionally significant role of CD52 blockade on CNS neurons and microglia. The beneficial effects of alemtuzumab in MS may be exclusively mediated by peripheral immune mechanisms.

Signatures of immune reprogramming in anti-CD52 therapy of MS: markers for risk stratification and treatment response

Background

Multiple sclerosis is one of the most prevalent neurological diseases in young adults affecting over 2 million people worldwide. Alemtuzumab is a highly effective therapy in relapsing remitting MS. Alemtuzumab is a monoclonal CD52 antibody that proved its efficacy against an active comparator (interferon [IFN]-β1a) in a phase II trial and two phase III trials regarding clinical and MRI outcomes. Nevertheless, the exact mode of action is still unknown. Alemtuzumab is commonly associated with secondary autoimmune disorders significantly affecting the risk-benefit ratio. Therefore, new biomarkers predicting treatment response and adverse events are urgently needed. This study aims to further elucidate the mechanism of action of the neuroprotective potential of alemtuzumab in relapsing-remitting multiple sclerosis (RRMS).

Methods/Design

This is a 3-year multicentre, explorative study including overall 150 patients comprising three different groups: (i) de novo patients prior and after alemtuzumab treatment initiation, (ii) patients under alemtuzumab treatment and (iii) patients requiring more than two alemtuzumab infusions. Peripheral blood and serum samples will be collected semi-annually for several in vitro/ex vivo assays to detect and characterize immune cells including their functional activity. Furthermore, data of MRI scans and disease-related impairment (using EDSS and MSFC), as well as the number and time of relapses, will be assessed. The clinical study is registered at clinicaltrials.gov (NCT04082260).

Perspective

Our study will provide deep insights into the underlying immunological changes in a longitudinal analysis of alemtuzumab treated RRMS patients. By combining clinical, radiological and functional immune-phenotype data, we will be able to identify biomarkers and/or immune signatures predicting treatment response and adverse events. Thereby, the understanding of the mechanisms of action of alemtuzumab will improve its efficacy and safety for present and future patients.

Periventricular magnetisation transfer ratio abnormalities in multiple sclerosis improve after alemtuzumab

BACKGROUND

In multiple sclerosis (MS), disease effects on magnetisation transfer ratio (MTR) increase towards the ventricles. This periventricular gradient is evident shortly after first symptoms and is independent of white matter lesions.

OBJECTIVE

To explore if alemtuzumab, a peripherally acting disease-modifying treatment, modifies the gradient's evolution, and whether baseline gradients predict on-treatment relapses.

METHODS

Thirty-four people with relapsing-remitting MS underwent annual magnetic resonance imaging (MRI) scanning (19 receiving alemtuzumab (four scans each), 15 untreated (three scans each)). The normal-appearing white matter was segmented into concentric bands. Gradients were measured over the three bands nearest the ventricles. Mixed-effects models adjusted for age, gender, relapse rate, lesion number and brain parenchymal fraction compared the groups' baseline gradients and evolution.

RESULTS

Untreated, the mean MTR gradient increased (+0.030 pu/band/year) but decreased following alemtuzumab (-0.045 pu/band/year, p = 0.037). Within the alemtuzumab group, there were no significant differences in baseline lesion number (p = 0.568) nor brain parenchymal fraction (p = 0.187) between those who relapsed within 4 years (n = 4) and those who did not (n = 15). However, the baseline gradient was significantly different (p = 0.020).

CONCLUSION

Untreated, abnormal periventricular gradients worsen with time, but appear reversible with peripheral immunotherapy. Baseline gradients - but not lesion loads or brain volumes - may predict on-treatment relapses. Larger confirmatory studies are required.

Best Practices for Long-Term Monitoring and Follow-Up of Alemtuzumab-Treated MS Patients in Real-World Clinical Settings

Multiple sclerosis (MS) is a chronic autoimmune neurological disease that typically affects young adults, causing irreversible physical disability and cognitive impairment. Alemtuzumab, administered intravenously as 2 initial courses of 12 mg/day (5 consecutive days at baseline, and 3 consecutive days 12 months later), resulted in significantly greater improvements in clinical and MRI outcomes vs. subcutaneous interferon beta-1a over 2 years in patients with active relapsing-remitting MS (RRMS) who were either treatment-naive (CARE-MS I; NCT00530348) or had an inadequate response to prior therapy (CARE-MS II; NCT00548405). Efficacy with alemtuzumab was maintained over 7 years in subsequent extension studies (NCT00930553; NCT02255656), in the absence of continuous treatment and with a consistent safety profile. There is an increased incidence of autoimmune events in patients treated with alemtuzumab (mainly thyroid events, but also immune thrombocytopenia and nephropathy), which imparts a need for mandatory safety monitoring for 4 years following the last treatment. The risk management strategy for alemtuzumab-treated patients includes laboratory monitoring and a comprehensive patient education and support program that enables early detection and effective management of autoimmune events, yielding optimal outcomes for MS patients. Here we provide an overview of tools and techniques that have been implemented in real-world clinical settings to reduce the burden of monitoring for both patients and healthcare providers, including customized educational materials, the use of social media, and interactive online databases for managing healthcare data. Many practices are also enhancing patient outreach efforts through coordination with specialized nursing services and ancillary caregivers. The best practice recommendations for safety monitoring described in this article, based on experiences in real-world clinical settings, may enable early detection and management of autoimmune events, and help with implementation of monitoring requirements while maximizing the benefits of alemtuzumab treatment for MS patients.

Immune cell derived BDNF does not mediate neuroprotection of the murine anti-CD52 antibody in a chronic autoimmune mouse model

The murine anti-CD52 antibody, an equivalent of the humanized antibody alemtuzumab, which is successfully used in the treatment of multiple sclerosis, was used to explore a potential neuroprotective effect driven by immune cell derived brain-derived neurotrophic factor (BDNF). Therefore, lineage specific constitutive knock-out mice with a BDNF deficiency in T cells and macrophages were used and compared to treated wildtype mice. Neither therapeutic nor preventive application of the murine anti-CD52 antibody in an animal model of multiple sclerosis, the MOG_35-55 EAE, revealed a beneficial contribution of immune cell derived BDNF to the disease outcome. Furthermore, preventive application of the murine anti-CD52 antibody worsened the clinical EAE disease course and could only be overcome by a prolonged recovery phase after treatment and before disease induction.

Alemtuzumab as Treatment for Multiple Sclerosis

Alemtuzumab, the first monoclonal antibody to be used as a therapy and the first to be humanized, was introduced into the treatment of multiple sclerosis in 1991 after its successful use in hematology, oncology, and transplantation medicine. One phase 2 and two phase 3 trials of this lymphocyte-depleting agent have established alemtuzumab's superior efficacy to interferon β-1a over the short term (2-3 years) with greater relapse rate reduction, reduced accumulation of disability, and more frequent sustained improvement in disability. Longer-term extension studies show durable effects on slowing cerebral atrophy over 6 years and maintained low relapse rates over 10 years, despite roughly half of patients not needing further dosing. Homeostatic proliferation of residual T cells after alemtuzumab-induced lymphopenia is probably responsible for its most common side effects: secondary autoimmunity 1 or 2 years after the last infusion of alemtuzumab affecting the thyroid gland (30% of patients), platelets (1%), or renal glomeruli (0.1%). With the prerequisite of patient and physician adherence to a prolonged safety-monitoring protocol, alemtuzumab offers durable high efficacy from infrequent dosing.

Clinical pharmacology of alemtuzumab, an anti-CD52 immunomodulator, in multiple sclerosis

Alemtuzumab, a humanized anti‐CD52 monoclonal antibody, is approved for treatment of relapsing multiple sclerosis (MS). In the Phase II/III trials, patients received 12 or 24 mg/day of alemtuzumab in two treatment courses (5 days for course 1 and 3 days for course 2), 12 months apart. Serum concentrations of alemtuzumab peaked on the last day of dosing in each course and mostly fell below the limit of quantitation by day 30. Alemtuzumab rapidly depleted circulating T and B lymphocytes, with the lowest observed values occurring within days. Lymphocytes repopulated over time, with B cell recovery usually complete within 6 months. T lymphocytes recovered more slowly and generally did not return to baseline by 12 months post‐treatment. Approximately 40 and 80% of patients had total lymphocyte counts, reaching the lower limit of normal by 6 and 12 months after each course, respectively. The clearance of alemtuzumab is dependent on circulating lymphocyte count. A majority of treated patients tested positive for anti‐alemtuzumab antibodies, including inhibitory antibodies, during the 2‐year studies, and a higher proportion of patients tested positive in course 2 than in course 1. The presence of anti‐alemtuzumab antibody appeared to be associated with slower clearance of alemtuzumab from the circulation but had no impact on the pharmacodynamics. No effects of age, race or gender on the pharmacokinetics or pharmacodynamics were observed. Together, the pharmacokinetics, pharmacodynamics and immunogenicity results support the continued development and use of alemtuzumab for the treatment of MS, and probably explain its sustained effects beyond the dosing interval.

Anti-CD52 antibody treatment depletes B cell aggregates in the central nervous system in a mouse model of multiple sclerosis

Background

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) for which several new treatment options were recently introduced. Among them is the monoclonal anti-CD52 antibody alemtuzumab that depletes mainly B cells and T cells in the immune periphery. Considering the ongoing controversy about the involvement of B cells and in particular the formation of B cell aggregates in the brains of progressive MS patients, an in-depth understanding of the effects of anti-CD52 antibody treatment on the B cell compartment in the CNS itself is desirable.

Methods

We used myelin basic protein (MBP)-proteolipid protein (PLP)-induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 (B6) mice as B cell-dependent model of MS. Mice were treated intraperitoneally either at the peak of EAE or at 60 days after onset with 200 μg murine anti-CD52 vs. IgG2a isotype control antibody for five consecutive days. Disease was subsequently monitored for 10 days. The antigen-specific B cell/antibody response was measured by ELISPOT and ELISA. Effects on CNS infiltration and B cell aggregation were determined by immunohistochemistry. Neurodegeneration was evaluated by Luxol Fast Blue, SMI-32, and Olig2/APC staining as well as by electron microscopy and phosphorylated heavy neurofilament serum ELISA.

Results

Treatment with anti-CD52 antibody attenuated EAE only when administered at the peak of disease. While there was no effect on the production of MP4-specific IgG, the treatment almost completely depleted CNS infiltrates and B cell aggregates even when given as late as 60 days after onset. On the ultrastructural level, we observed significantly less axonal damage in the spinal cord and cerebellum in chronic EAE after anti-CD52 treatment.

Conclusion

Anti-CD52 treatment abrogated B cell infiltration and disrupted existing B cell aggregates in the CNS.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1263-9) contains supplementary material, which is available to authorized users.

Multiple sclerosis: genetics, biomarkers, treatments

PURPOSE OF REVIEW

We discuss new paradigms for understanding the immunopathology of multiple sclerosis through the recent development of high throughput genetic analysis, emergence of numerous candidate biomarkers, and the broadening of the treatment arsenal.

RECENT FINDINGS

The recent use of genome wide association studies provide new tools for a better understanding of multiple sclerosis etiology. Genome-wide association studies have identified many genes implicated in immune regulation and the next step will be to elucidate how those genetic variations influence immune cell function to drive disease development and progression. Furthermore, patient care has seen the emergence of new biomarkers for monitoring disease progression and response to treatment. Finally, the introduction of numerous immunomodulatory treatments will likely improve clinical outcome of multiple sclerosis patients in the future.

SUMMARY

Breakthroughs in the field of multiple sclerosis have led to a better understanding of the physiopathology of the disease, follow up, and treatment of the patients that develop relapsing remitting multiple sclerosis. The next challenge for multiple sclerosis will be to press forward to model and decipher multiple sclerosis progression, which will help both to develop therapeutics and generate knowledge about mechanisms of neurodegeneration.

Sequencing of high-efficacy disease-modifying therapies in multiple sclerosis: perspectives and approaches

Multiple sclerosis (MS) is characterized by chronic inflammation in conjunction with neurodegeneration within the central nervous system. Most individuals with MS begin with a relapsing remitting course that later transitions to secondary progressive MS. Currently available disease-modifying therapies (DMTs) for relapsing MS have been demonstrated to reduce disease activity, however most patients require a change in therapy over the course of their disease. Treatment goals include the prevention of relapses and disability accumulation and to achieve this objective requires careful planning. Sequencing of DMTs for individual patients should be designed in such a way to maximize disease control and minimize risk based on the mechanism of action, pharmacokinetic and pharmacodynamic properties of each therapy. This includes the DMT patients are being switched from to those they are being switched to. The reversibility of immune system effects should be a key consideration for DMT sequence selection. This feature varies across DMTs and should factor more prominently in decision making as newer treatments become available for the prevention of disability accumulation in patients with progressive MS. In this short review, we discuss the landscape of existing therapies with an eye to the future when planning for optimal DMT sequencing. While no cure exists for MS, efforts are being directed toward research in neuroregeneration with the hope for positive outcomes.

Cell-based therapeutic strategies for multiple sclerosis

The availability of multiple disease-modifying medications with regulatory approval to treat multiple sclerosis illustrates the substantial progress made in therapy of the disease. However, all are only partially effective in preventing inflammatory tissue damage in the central nervous system and none directly promotes repair. Cell-based therapies, including immunoablation followed by autologous haematopoietic stem cell transplantation, mesenchymal and related stem cell transplantation, pharmacologic manipulation of endogenous stem cells to enhance their reparative capabilities, and transplantation of oligodendrocyte progenitor cells, have generated substantial interest as novel therapeutic strategies for immune modulation, neuroprotection, or repair of the damaged central nervous system in multiple sclerosis. Each approach has potential advantages but also safety concerns and unresolved questions. Moreover, clinical trials of cell-based therapies present several unique methodological and ethical issues. We summarize here the status of cell-based therapies to treat multiple sclerosis and make consensus recommendations for future research and clinical trials.

Understanding the positive benefit:risk profile of alemtuzumab in relapsing multiple sclerosis: perspectives from the Alemtuzumab Clinical Development Program

The introduction of high-efficacy therapies for relapsing–remitting multiple sclerosis has driven re-evaluation of treatment goals and benefit:risk considerations in treatment choice. In the alemtuzumab Phase II and III clinical trials, patients treated with alemtuzumab 12 mg versus subcutaneous interferon beta-1a demonstrated significantly reduced annualized relapse rates and improved magnetic resonance imaging outcomes, and were significantly more likely to achieve no evidence of disease activity and reduction in brain volume loss. In two of the studies, alemtuzumab-treated patients had a significantly reduced risk of 6-month confirmed disease worsening, compared with subcutaneous interferon beta-1a. Benefits were maintained throughout 5 years, with a majority of patients receiving no alemtuzumab retreatment or other disease-modifying therapy. Trial results support alemtuzumab’s manageable, consistent safety profile in relapsing–remitting multiple sclerosis. Infusion-associated reactions, the most frequent adverse events (AEs), can be minimized by corticosteroid pretreatment, monitoring, and symptomatic management. Other AEs include infections and autoimmune events. Oral anti-herpes prophylaxis should be initiated on the first day of each alemtuzumab treatment course and continued according to local guidelines. Overall cancer risk was lower in the alemtuzumab clinical trials than in a reference population; however, continuing surveillance will determine if alemtuzumab may be associated with certain malignancies such as thyroid papillary carcinoma and melanoma, which are currently identified as potential risks. The post-approval risk management strategy includes a safety monitoring program. Autoimmune AEs (thyroid events, immune thrombocytopenia, nephropathies) can be detected in a timely manner with the monitoring program, which includes physician and patient education about the signs and symptoms, monthly renal and hematologic monitoring, and quarterly thyroid function monitoring for 48 months after the last alemtuzumab course. Education, vigilance by physicians and patients, and monthly laboratory monitoring are recommended to maintain alemtuzumab’s positive benefit:risk profile.

Alemtuzumab for Multiple Sclerosis

Alemtuzumab is a humanised anti-CD52 monoclonal antibody approved for use in active, relapsing multiple sclerosis (MS). Administration results in a rapid depletion of circulating lymphocytes with a subsequent beneficial immune reconstitution. Early open-label experience and recent clinical trials have demonstrated a dramatic effect on relapse rates as well as a positive effect on radiological disease outcomes and disability measures. Despite a mechanism of action that results in profound lymphopaenia, opportunistic infections are rarely seen and no excess association with malignancy has been identified. However, acquired autoimmune disease (AID) is a common adverse event following treatment, necessitating rigorous monitoring in order to facilitate prompt detection and management. Despite this issue, a unique dosing schedule and durability of effect make alemtuzumab a welcome addition to currently available treatment options for MS.

The immunological function of CD52 and its targeting in organ transplantation

INTRODUCTION

CD52 (Campath-1 antigen), a glycoprotein of 12 amino acids anchored to glycosylphosphatidylinositol, is widely expressed on the cell surface of immune cells, such as mature lymphocytes, natural killer cells (NK), eosinophils, neutrophils, monocytes/macrophages, and dendritic cells (DCs). The anti-CD52 mAb, alemtuzumab, was used widely in clinics for the treatment of patients such as organ transplantation. In the present manuscript, we will briefly summarize the immunological function of CD52 and discuss the application of anti-CD52 mAb in transplantation settings.

FINDINGS

We reviewed studies published until July 2016 to explore the role of CD52 in immune cell function and its implication in organ transplantation. We showed that ligation of cell surface CD52 molecules may offer costimulatory signals for T-cell activation and proliferation. However, soluble CD52 molecules will interact with the inhibitory sialic acid-binding immunoglobulin-like lectin 10 (Siglec10) to significantly inhibit T cell proliferation and activation. Although the physiological and pathological significances of CD52 molecules are still poorly understood, the anti-CD52 mAb, alemtuzumab, was used widely for the treatment of patients with chronic lymphocytic leukemia, autoimmune diseases as well as cell and organ transplantation in clinics.

CONCLUSION

Studies clearly showed that CD52 can modulate T-cell activation either by its intracellular signal pathways or by the interaction of soluble CD52 and Siglec-10 expressing on T cells. However, the regulatory functions of CD52 on other immune cell subpopulations in organ transplantation require to be studied in the near future.

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.

Excitotoxins, Mitochondrial and Redox Disturbances in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). There is increasing evidence that MS is not only characterized by immune mediated inflammatory reactions, but also by neurodegenerative processes. There is cumulating evidence that neurodegenerative processes, for example mitochondrial dysfunction, oxidative stress, and glutamate (Glu) excitotoxicity, seem to play an important role in the pathogenesis of MS. The alteration of mitochondrial homeostasis leads to the formation of excitotoxins and redox disturbances. Mitochondrial dysfunction (energy disposal failure, apoptosis, etc.), redox disturbances (oxidative stress and enhanced reactive oxygen and nitrogen species production), and excitotoxicity (Glu mediated toxicity) may play an important role in the progression of the disease, causing axonal and neuronal damage. This review focuses on the mechanisms of mitochondrial dysfunction (including mitochondrial DNA (mtDNA) defects and mitochondrial structural/functional changes), oxidative stress (including reactive oxygen and nitric species), and excitotoxicity that are involved in MS and also discusses the potential targets and tools for therapeutic approaches in the future.

Update on disease-modifying therapies for multiple sclerosis

Multiple sclerosis (MS) is an autoimmune, demyelinating disease of the central nervous system (CNS). It predominantly affects young women and is one of the most common causes of disability in young adults. MS is characterized by formation of white matter lesions in the CNS as a result of inflammation, demyelination, and axonal loss. Treatment has been a focus of neurological research for over 60 years. A number of disease-modifying therapies (DMTs) have become available making MS a treatable disease. These compounds target the inflammatory response in MS. They work by decreasing the chances of relapse, decreasing the chances of new lesion formation seen on MRI of the CNS and slowing the accumulation of disability. The first drugs for MS to be available were interferon-β and glatiramer acetate. These work by modulating the inflammatory response via different mechanisms that are briefly discussed. Newer agents have since become available and have significantly changed the dynamics of MS treatment. These include fingolimod, dimethyl fumarate and teriflunomide, which are oral agents. Other second-line and third-line Food and Drug Administration (FDA) approved medications include natalizumab and alemtuzumab. Natalizumab is considered one of the most potent treatments for relapse prevention. However, the high risk of progressive multifocal leukoencephalopathy (PML), which is caused by JC virus infection in the brain, tempers the more widespread use of this agent; nevertheless, JC virus antibody tests have helped to stratify the risk of PML. Alemtuzumab, which also has a considerable side effect profile, is likewise highly efficacious. Ocrelizumab, a monoclonal antibody to CD20 on B cells, is a highly effective agent for MS that is likely to be approved soon by the FDA. MS is a major contributor to healthcare costs and it is critical that healthcare providers be aware of the availability and benefits of DMTs. It is imperative that prompt and adequate treatment be established on diagnosis. Changes in therapy should be considered when there is evidence of disease activity as well as accumulation of disability or safety or tolerability concerns.

Intervening to reduce the risk of future disability from multiple sclerosis: are we there yet?

Disease-modifying therapies (DMTs) delay or may prevent the progression of patients with high-risk clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (MS), and from relapsing-remitting MS to secondary progressive MS. Current evidence on the effects of DMT on disability in MS is supported by the use of the Expanded Disability Status Scale (EDSS), which is dominated by ambulation, and usually used as a secondary outcome measure. Less is known about the long-term effects of DMTs on other aspects of functional status, particularly cognition, which is a key determinant of ability to work. The time scale for measurements of disability is at most a few years, with scant data from more than 10 years of observation. Longer prospective follow-up of large numbers of patients with CIS is needed to determine whether early intervention with a DMT influences long-term disease progression. Finally, the emergence of the radiologically isolated syndrome (RIS) as a clinical entity has shifted the debate about when to intervene to an even earlier time frame. Balancing the significant side-effects associated with DMT in general and the expected outcome of pharmacologic intervention is increasingly problematic for managing patients with uncertain prognosis, as many patients may have low-risk CIS, benign MS or patients with RIS only. Preventing long-term disability in MS should be recognised more clearly as an important outcome in its own right, with disability measured more consistently with more sensitive instruments beyond the use of the EDSS.

Role of Oligodendrocyte Dysfunction in Demyelination, Remyelination and Neurodegeneration in Multiple Sclerosis

Oligodendrocytes (OLs) are the myelinating cells of the central nervous system (CNS) during development and throughout adulthood. They result from a complex and well controlled process of activation, proliferation, migration and differentiation of oligodendrocyte progenitor cells (OPCs) from the germinative niches of the CNS. In multiple sclerosis (MS), the complex pathological process produces dysfunction and apoptosis of OLs leading to demyelination and neurodegeneration. This review attempts to describe the patterns of demyelination in MS, the steps involved in oligodendrogenesis and myelination in healthy CNS, the different pathways leading to OLs and myelin loss in MS, as well as principles involved in restoration of myelin sheaths. Environmental factors and their impact on OLs and pathological mechanisms of MS are also discussed. Finally, we will present evidence about the potential therapeutic targets in re-myelination processes that can be accessed in order to develop regenerative therapies for MS.

Alemtuzumab improves preexisting disability in active relapsing-remitting MS patients

Objective:

To characterize effects of alemtuzumab treatment on measures of disability improvement in patients with relapsing-remitting multiple sclerosis (RRMS) with inadequate response (≥1 relapse) to prior therapy.

Methods:

Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis (CARE-MS) II, a 2-year randomized, rater-blinded, active-controlled, head-to-head, phase 3 trial, compared efficacy and safety of alemtuzumab 12 mg with subcutaneous interferon-β-1a (SC IFN-β-1a) 44 μg in patients with RRMS. Prespecified and post hoc disability outcomes based on Expanded Disability Status Scale (EDSS), Multiple Sclerosis Functional Composite (MSFC), and Sloan low-contrast letter acuity (SLCLA) are reported, focusing on improvement of preexisting disability in addition to slowing of disability accumulation.

Results:

Alemtuzumab-treated patients were more likely than SC IFN-β-1a–treated patients to show improvement in EDSS scores (p < 0.0001) on all 7 functional systems. Significantly more alemtuzumab patients demonstrated 6-month confirmed disability improvement. The likelihood of improved vs stable/worsening MSFC scores was greater with alemtuzumab than SC IFN-β-1a (p = 0.0300); improvement in MSFC scores with alemtuzumab was primarily driven by the upper limb coordination and dexterity domain. Alemtuzumab-treated patients had more favorable changes from baseline in SLCLA (2.5% contrast) scores (p = 0.0014) and MSFC + SLCLA composite scores (p = 0.0097) than SC IFN-β-1a–treated patients.

Conclusions:

In patients with RRMS and inadequate response to prior disease-modifying therapies, alemtuzumab provides greater benefits than SC IFN-β-1a across several disability outcomes, reflecting improvement of preexisting disabilities.

Classification of evidence:

This study provides Class I evidence (based on rater blinding and a balance in baseline characteristics between arms) that alemtuzumab modifies disability measures favorably compared with SC IFN-β-1a.

Superior MRI outcomes with alemtuzumab compared with subcutaneous interferon β-1a in MS

Objective:

To describe detailed MRI results from 2 head-to-head phase III trials, Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis Study I (CARE-MS I; NCT00530348) and Study II (CARE-MS II; NCT00548405), of alemtuzumab vs subcutaneous interferon β-1a (SC IFN-β-1a) in patients with active relapsing-remitting multiple sclerosis (RRMS).

Methods:

The impact of alemtuzumab 12 mg vs SC IFN-β-1a 44 μg on MRI measures was evaluated in patients with RRMS who were treatment-naive (CARE-MS I) or who had an inadequate response, defined as at least one relapse, to prior therapy (CARE-MS II).

Results:

Both treatments prevented T2-hyperintense lesion volume increases from baseline. Alemtuzumab was more effective than SC IFN-β-1a on most lesion-based endpoints in both studies (p < 0.05), including decreased risk of new/enlarging T2 lesions over 2 years and gadolinium-enhancing lesions at year 2. Reduced risk of new T1 lesions (p < 0.0001) and gadolinium-enhancing lesion conversion to T1-hypointense black holes (p = 0.0078) were observed with alemtuzumab vs SC IFN-β-1a in CARE-MS II. Alemtuzumab slowed brain volume loss over 2 years in CARE-MS I (p < 0.0001) and II (p = 0.012) vs SC IFN-β-1a.

Conclusions:

Alemtuzumab demonstrated greater efficacy than SC IFN-β-1a on MRI endpoints in active RRMS. The superiority of alemtuzumab was more prominent during the second year of both studies. These findings complement the superior clinical efficacy of alemtuzumab over SC IFN-β-1a in RRMS.

ClinicalTrials.gov identifier:

NCT00530348 and NCT00548405.

Classification of evidence:

The results reported here provide Class I evidence that, for patients with active RRMS, alemtuzumab is superior to SC IFN-β-1a on multiple MRI endpoints.

The role of growth factors as a therapeutic approach to demyelinating disease

A variety of growth factors are being explored as therapeutic agents relevant to the axonal and oligodendroglial deficits that occur as a result of demyelinating lesions such as are evident in Multiple Sclerosis (MS). This review focuses on five such proteins that are present in the lesion site and impact oligodendrocyte regeneration. It then presents approaches that are being exploited to manipulate the lesion environment affiliated with multiple neurodegenerative diseases and suggests that the utility of these approaches can extend to demyelination. Challenges are to further understand the roles of specific growth factors on a cellular and tissue level. Emerging technologies can then be employed to optimize the use of growth factors to ameliorate the deficits associated with demyelinating degenerative diseases.

The Effect of Disease-Modifying Drugs on Brain Atrophy in Relapsing-Remitting Multiple Sclerosis: A Meta-Analysis

Background

The quantification of brain atrophy in relapsing-remitting multiple sclerosis (RRMS) may serve as a marker of disease progression and treatment response. We compared the association between first-line (FL) or second-line (SL) disease-modifying drugs (DMDs) and brain volume changes over time in RRMS.

Materials and Methods

We reviewed clinical trials in RRMS between January 1, 1995 and June 1, 2014 that assessed the effect of DMDs and reported data on brain atrophy in Medline, Embase, the Cochrane database and meeting abstracts. First, we designed a meta-analysis to directly compare the percentage brain volume change (PBVC) between FLDMDs and SLDMDs at 24 months. Second, we conducted an observational and longitudinal linear regression analysis of a 48-month follow-up period. Sensitivity analyses considering PBVC between 12 and 48 months were also performed.

Results

Among the 272 studies identified, 117 were analyzed and 35 (18,140 patients) were included in the analysis. Based on the meta-analysis, atrophy was greater for the use of an FLDMD than that of an SLDMD at 24 months (primary endpoint mean difference, -0.86; 95% confidence interval: -1.57–-0.15; P = 0.02). Based on the linear regression analysis, the annual PBVC significantly differed between SLDMDs and placebo (-0.27%/y and -0.50%/y, respectively, P = 0.046) but not between FLDMDs (-0.33%/y) and placebo (P = 0.11) or between FLDMDs and SLDMDs (P = 0.49). Based on sensitivity analysis, the annual PBVC was reduced for SLDMDs compared with placebo (-0.14%/y and -0.56%/y, respectively, P<0.001) and FLDMDs (-0.46%/y, P<0.005), but no difference was detected between FLDMDs and placebo (P = 0.12).

Conclusions

SLDMDs were associated with reduced PBVC slope over time in RRMS, regardless of the period considered. These results provide new insights into the mechanisms underlying atrophy progression in RRMS.

ALAIN01--Alemtuzumab in autoimmune inflammatory neurodegeneration: mechanisms of action and neuroprotective potential

BACKGROUND

Alemtuzumab (Lemtrada®) is a newly approved therapeutic agent for relapsing-remitting multiple sclerosis (RRMS). In previous phase II and III clinical trials, alemtuzumab has proven superior efficacy to subcutaneous interferon beta-1a concerning relapse rate and disability progression with unprecedented durability and long-lasting freedom of disease activity. The humanized monoclonal antibody targets CD52, leading to a rapid and long-lasting depletion, especially of B and T cells. Arising from hematopoietic precursor cells a fundamental reprogramming of the immune system restores tolerogenic networks effectively suppressing autoimmune inflammatory responses in the central nervous system (CNS). Despite its favourable effects alemtuzumab holds a severe risk of side effects with secondary autoimmunity being the most considerable. Markers for risk stratification and treatment response improving patient selection and therapy guidance are a big unmet need for MS patients and health care providers.

METHODS/DESIGN

This is a mono center, single arm, explorative phase IV study including 15 patients with highly active RRMS designed for 3 years. Patients will be studied by a high-resolution analysis comprising a repertoire of various immunological assays for the detection of immune cells and their function in peripheral blood as well as the cerebrospinal fluid (CSF). These assays encompass a number of experiments investigating immune cell subset composition, activation status, cytokine secretion, migratory capacity, potential neuroprotective properties and cytolytic activity complemented by instrument-based diagnostics like MRI scans, evoked potentials and optical coherence tomography (OCT).

DISCUSSION

Our study represents the first in-depth and longitudinal functional analysis of key immunological parameters in the periphery and the CNS compartment underlying the fundamental effects of alemtuzumab in MS patients. By combining clinical, experimental and MRI data our study will provide a deeper understanding of alemtuzumab's mechanisms of action (MOA) potentially identifying immune signatures associated with treatment response or the development of secondary autoimmunity. After validation in larger cohorts this might help to improve efficacy and safety of alemtuzumab therapy in RRMS patients.

TRIAL REGISTRATION

NCT02419378 (clinicaltrials.gov), registered 31 March 2015.

Alemtuzumab improves neurological functional systems in treatment-naive relapsing-remitting multiple sclerosis patients

BACKGROUND

Individual functional system scores (FSS) of the Expanded Disability Status Scale (EDSS) play a central role in determining the overall EDSS score in patients with early-stage multiple sclerosis (MS). Alemtuzumab treatment improves preexisting disability for many patients; however, it is unknown whether improvement is specific to certain functional systems.

OBJECTIVE

We assessed the effect of alemtuzumab on individual FSS of the EDSS.

METHODS

CAMMS223 was a 36-month, rater-blinded, phase 2 trial; treatment-naive patients with active relapsing-remitting MS, EDSS ≤3, and symptom onset within 3 years were randomized to annual courses of alemtuzumab or subcutaneous interferon beta-1a (SC IFNB-1a) 44 μg three times weekly.

RESULTS

Alemtuzumab-treated patients had improved outcomes versus SC IFNB-1a patients on most FSS at Month 36; the greatest effect occurred for sensory, pyramidal, and cerebellar FSS. Among patients who experienced 6-month sustained accumulation of disability, clinical worsening occurred most frequently in the brainstem and sensory systems. For patients with 6-month sustained reduction in preexisting disability, pyramidal and sensory systems contributed most frequently to clinical improvement.

CONCLUSIONS

Alemtuzumab demonstrated a broad treatment effect in improving preexisting disability. These findings may influence treatment decisions in patients with early, active relapsing-remitting MS displaying neurological deficits. ClinicalTrials.gov Identifier NCT00050778.