Mitoxantrone as rescue therapy in worsening relapsing-remitting MS patients receiving IFN-beta

Mucosal-Associated Invariant T Cell Features and TCR Repertoire Characteristics During the Course of Multiple Sclerosis

Objective: To investigate the frequency, phenotype, function, and longitudinal repertoire of mucosal-associated invariant T (MAIT) cells in relapsing remitting multiple sclerosis (RRMS) and primary progressive multiple sclerosis (PPMS) patients.

Methods: Forty-five RRMS patients in remission, 20 RRMS patients experiencing exacerbations, 15 PPMS patients, and 30 healthy controls (HCs) were included in the study. MAIT cells were identified phenotypically as CD3⁺ TCRγδ⁻ Vα7.2 + CD161^high. In 15 patients, MAIT cell number and MRI lesions were evaluated every 6 months, for 36 months. MAIT cell TCRVβ repertoire was defined using single-cell cloning and mRNA sequencing.

Results: Circulating MAIT cells were significantly reduced in both RRMS and PPMS patients, particularly during exacerbations, compared to healthy subjects. This decrease was accompanied by pro-inflammatory cytokine production (TNF-α, IFN-γ, IL-17, and GM-CSF). Three months post-exacerbation, peripheral blood MAIT cell percentages increased significantly along with clinical recovery. Likewise, we observed inverse correlation between MRI lesions and peripheral blood MAIT cell numbers. In paired samples, MAIT cell percentage was significantly higher in CSF than in peripheral blood, suggesting MAIT cell migration through the blood–brain barrier. Finally, MAIT cells showed limited TCRVβ repertoires, in both CSF and peripheral blood, which remained stable over time.

Conclusions: MAIT cell levels correlated with MS course both clinically and radiologically, showing marked and sustained oligoclonality. These findings may contribute to a better understanding of pathophysiological phenomena underlying the course of MS, and discovery of MAIT cell inhibitors could pave the way for the development of new therapeutic strategies.

Intractable and highly active relapsing multiple sclerosis - role of alemtuzumab

Alemtuzumab is a humanized recombinant monoclonal antibody that was recently approved by the US Food and Drug Administration and the European Medicines Agency for the management of relapsing forms of multiple sclerosis (MS). It has been utilized for the management of chronic lymphocytic leukemia, bone marrow and renal transplantation, or graft versus host disease. Because of its immunomodulatory properties, it was brought into clinical development in MS. One Phase II (CAMMS223) and two Phase III clinical trials (CARE-MSI and -II) have evaluated the safety and efficacy of alemtuzumab in patients with relapsing-remitting MS. Even though its efficacy profile and long-lasting effect have attracted much interest among physicians and patients, it has significant potential adverse effects that may limit its use to patients with active disease. Here, we review the history of drug development of alemtuzumab. Furthermore, we outline the postulated mechanisms of action, clinical evidence, and safety of alemtuzumab for its use as a disease-modifying agent in active and highly active MS.

Definitions of breakthrough disease and second-line agents

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

Chitinase effects on immune cell response in neuromyelitis optica and multiple sclerosis

BACKGROUND

Recent studies conducted in arthritis, asthma, and inflammatory bowel disease suggest that chitinases are important in inflammatory processes and tissue remodeling.

OBJECTIVE

To investigate the role of chitinases in multiple sclerosis (MS) and neuromyelitis optica (NMO).

METHODS

Levels of chitotriosidase, acid mammalian chitinase (AMCase), and chitinase 3-like-1 (CHI3L1) were measured using ELISA, in cerebrospinal fluid (CSF) and in serum from 24 patients with relapsing remitting (RR) MS, 24 patients with secondary progressive (SP) MS, 12 patients with NMO, 24 patients with other inflammatory neurological diseases (OIND), and 24 healthy controls (HCs). The number of anti-MOG cytokine-secreting cells was studied using ELISPOT. Eotaxins, MCP-1, RANTES, and IL-8 were assessed using ELISA. Cell transmigration was determined using an in vitro blood-brain barrier (BBB) model, in the presence and absence of chitinases.

RESULTS

CSF chitinase levels were significantly increased in patients with RRMS and NMO compared with HCs and patients with SPMS and OIND. In contrast, no significant differences were detected in serum chitinase levels between groups. Chitinase CSF levels showed correlation with anti-MOG IL-13-producing cells, and eotaxin levels. In vitro experiments showed macrophage chitinase secretion was significantly increased by IL-13, but not by IL-5, IL-6, IL-12, or IFN-γ. Moreover, chitinases enhanced IL-8, RANTES, MCP-1, and eotaxin production, increasing migratory capacity in eosinophils, T cells, and macrophages across an in vitro BBB model.

CONCLUSIONS

Chitinases increased in the CSF from patients with NMO in response to IL-13. These enhanced levels could contribute to central nervous system inflammation by increasing immune cell migration across the BBB.

New approaches in the management of multiple sclerosis

Multiple sclerosis (MS) is a central nervous system chronic inflammatory disease that is characterized by an extensive and complex immune response. Scientific advances have occurred in immunology, pathophysiology, and diagnostic and clinical assessment tools, and recent discovery of unique therapeutic targets has spurred numerous Phase II and Phase III clinical trials. Reductions in MS relapse rates and improvements in T₂ or gadolinium-enhancing lesion burdens have been reported from Phase III trials that include fingolimod, alemtuzumab, cladribine, and rituximab. Promising Phase II trial data exist for teriflunomide, daclizumab, laquinimod, and fumarate. The optimism created by these favorable findings must be tempered with evaluation of the adverse effect profile produced by these new agents. Given the discovery of progressive multifocal leukoencephalopathy with the use of natalizumab, ongoing vigilance for rare and life-threatening reactions due to new agents should be paramount. Patients with MS often experience difficulty with ambulation, spasticity, and cognition. Recent clinical trial data from two Phase III dalfampridine-SR trials indicate certain patients receive benefits in ambulation. This article provides an overview of data from clinical trials of newer agents of potential benefit in MS.

Recognizing and treating suboptimally controlled multiple sclerosis: steps toward regaining command

OBJECTIVE

The therapies available today for multiple sclerosis (MS) reduce but do not fully control disease activity. The objective of this article is to review the definitions of and treatments for suboptimally controlled MS and highlight the challenges faced by clinicians to increase awareness of recognizing and managing patients with suboptimally controlled MS.

METHODS

Published literature describing treatment failure, treatment optimization paradigms or algorithms, clinical studies of therapies in patients with suboptimally controlled MS, or case reports of management of patients with suboptimally controlled MS were identified from searches of EMBASE and MEDLINE. This was supplemented with case reports and discussions from an expert panel meeting of MS specialists focused on the diagnosis and treatment of suboptimally controlled MS.

RESULTS

Several groups have created recommendations for evaluating suboptimal response to disease-modifying drugs (DMDs) in MS. Currently no robust evidence-based data exist to guide treatment decisions in patients who have suboptimal response to a particular therapy. In the absence of data, several treatment paradigms for suboptimally controlled MS have been proposed using a step therapy or platform therapy approach. Therapy modifications require consideration of disease- and patient-specific factors while accounting for the risk-benefit profile of the agent(s). Unapproved drugs and combination therapies should be reserved as agents of last resort because of the experimental nature of these treatments.

CONCLUSIONS

In the absence of evidence-based data, identifying and treating MS patients with suboptimal response to the available platform therapies remains challenging. Developing algorithms able to quantify breakthrough disease activity and suboptimal response to DMDs in individual MS patients remains an important target for the MS community. Consideration should be given for all reasons why a particular DMD may not be working for a given patient and for the use of an individualized step therapy.

Immunosuppression followed by immunomodulation

The recent emergence of 'higher efficacy/higher risk' therapies in relapsing remitting multiple sclerosis (RRMS) asks questions of current treatment paradigms in this disorder. For those patients who present with very aggressive relapsing disease or early treatment failure on an interferon, a number of treatment options need to be considered. One such strategy is that of induction treatment regimens combining a short-course of an immunosuppressive drug to enable prompt control of inflammatory disease activity, followed by maintenance therapy with an immunomodulatory treatment. Immunosuppressants in general cannot be given over extended periods because of toxicity associated with cumulative exposure. However, in the short term, the risks associated with their use are probably less than those risks associated with inadequate control of relapse activity in aggressive onset disease. In particular, several groups have investigated the potential use of mitoxantrone induction followed by maintenance therapy with glatiramer acetate (GA). The evidence emerging from such studies suggests that brief immunosuppression with mitoxantrone followed by maintenance therapy with GA may provide a synergistic effect on control of disease activity and can be administered with an acceptable risk. The effectiveness of such induction regimens should encourage physicians to reconsider thresholds to define treatment failure on 'first-line' therapies, the criteria for acceptable disease control, as well as the relative place of induction and escalation treatment strategies in the management of RRMS.

Back to the future for multiple sclerosis therapy: focus on current and emerging disease-modifying therapeutic strategies

The last decade has seen numerous advances in the treatment of multiple sclerosis with six immunotherapeutic agents licensed for use. Although these therapeutic agents have powerful effects upon the inflammatory phase of disease, they have limitations in treating the progression of disability and in their safety profile. This review focuses on our current understanding of first- and second-line treatments for multiple sclerosis, including combination therapies, and also discusses the most promising novel therapeutic strategies on the horizon. Such agents include orally administered immunosuppressive drugs, monoclonal antibodies, antigen-specific tolerance, and neural protection and repair strategies. The challenge ahead lies in the delivery of potent drugs to inhibit inflammation and neurodegeneration while limiting side effects. Further elucidation of the pathophysiology of disease may provide new clinical targets and disease-relevant biomarkers that, in combination with proteomics, may help personalize treatment to individual patients.

Immunosuppression in clinical practice: approaches to individualized therapy

Despite novel immunoactive agents, immunosuppressants still play a considerable role in the treatment of MS, especially in rapidly progressive cases. Given the limited tolerability and potentially severe side effects of most immunosuppressive drugs, identification of patients with a favorable benefit-risk profile is essential. A narrow therapeutic index, with sometimes high interindividual variability in terms of response and side effects may partially be explained by genetic factors affecting different metabolic pathways. Here, we will review practical aspects in the clinical use of immunosuppressants in MS and discuss approaches to individualized treatment schemes, including novel pharmacogenetic strategies.

Helminth infections associated with multiple sclerosis induce regulatory B cells

OBJECTIVE

To assess the importance of B-cell control during parasite infections in multiple sclerosis (MS) patients.

METHODS

Peripheral blood CD19+ B cells from 12 helminth-infected MS patients, 12 MS patients without infection, 10 patients infected with Trypanosoma cruzi, 8 subjects infected with Paracoccidioides brasiliensis, and 12 healthy control subjects were purified using magnetic cell sorting. Interleukin (IL)-4, IL-6, IL-10, tumor necrosis factor-alpha, lymphotoxin, transforming growth factor-beta, brain-derived neurotrophic factor, and nerve growth factor secretion were evaluated after stimulation with CDw32 L cells and CD40 antibody using enzyme-linked immunosorbent assays. The production of anti-myelin oligodendrocyte glycoprotein IgG and IgM antibodies was evaluated by enzyme-linked immunosorbent spot assays. Cell phenotype was assessed by flow cytometry.

RESULTS

Helminth infections in MS patients created a B-cell population producing high levels of IL-10, dampening harmful immune responses through a mechanism mediated, at least in part, by the ICOS-B7RP-1 pathway. The IL-10-producing B-cell phenotype detected expressed high levels of CD1d and was similar to the one observed in mature naive B2 cells (namely, CD11b(-), CD5(-), CD27(-), and IgD+). Moreover, B cells isolated from helminth-infected MS patients also produced greater amounts of brain-derived neurotrophic factor and nerve growth factor compared with those of normal subjects, T. cruzi-infected subjects, P. brasiliensis-infected subjects, or uninfected MS patients, raising the possibility that these cells may exert a neuroprotective effect on the central nervous system.

INTERPRETATION

Increased production of B-cell-derived IL-10 and of neurotrophic factors are part of the parasite's regulation of host immunity and can alter the course of MS, potentially explaining environmental-related MS suppression observed in areas with low disease prevalence.

Multiple sclerosis: new treatment trials and emerging therapeutic targets

PURPOSE OF REVIEW

This review focuses on new therapeutic strategies in multiple sclerosis.

RECENT FINDINGS

The past decade has marked the advent of various new therapeutic strategies in multiple sclerosis. Whereas the current armamentarium of immunomodulatory medications has demonstrated beneficial effects on the disease, more effective and tolerable therapies are needed. Several novel therapeutic strategies in testing include oral therapies, monoclonal antibodies, symptomatic treatments as well as insights into neuroprotection and repair. Ways to build upon existing therapies are also under investigation, including early initiation of treatment and various combination regimens.

SUMMARY

New therapies, along with variations of currently available treatments, may prove more efficacious and tolerable than the available arsenal of treatments. Nevertheless, as the treatment horizon broadens, choosing first-line therapies will become more complicated, with greater influence of risk-to-benefit ratios in light of premature safety data. Patient's clinical, paraclinical and biomarker fingerprint profiles may help elucidate disease subtypes as well as response to therapy in an effort to individualize treatment choice. A complete discussion of all studies currently underway is beyond the scope of this review, which will highlight recent promising therapeutic strategies under investigation in the field of multiple sclerosis.

Compared benefit of approved and experimental immunosuppressive therapeutic approaches in multiple sclerosis

An important amount has been learnt about the mechanisms of action, efficacy and long-term toxicities of mitoxantrone. Importantly, recent observations strongly suggest that early administration of potent immunosuppressants (mitoxantrone and alemtuzumab) is definitely more effective than approved immunomodulators to delay or even reverse disability progression. Given the cardiotoxicity of mitoxantrone, restricting exposure to the drug to 2 or 3 years, the benefits and risks of immunosuppressants previously used as off-label treatments (cyclophosphamide and cladribine) have been revisited, and the potential efficacy in multiple sclerosis of recent immunosuppressants used in other autoimmune diseases, organ transplantation and cancer therapy has received increasing attention. Those immunosuppressants comprise monoclonal antibodies targeting B cells, lymphocytes and monocytes, IL-2 receptor and alpha4 integrin, as well as new molecules (pixantrone and isoxazole derivatives) and a new generation of immunosuppressants (fingolimod), which modulate lymphocyte re-circulation. This review addresses the most recent data concerning the efficacy and safety of mitoxantrone and of new experimental therapies that are presently in progress.

Association between parasite infection and immune responses in multiple sclerosis

OBJECTIVE

To assess whether parasite infection is correlated with a reduced number of exacerbations and altered immune reactivity in multiple sclerosis (MS).

METHODS

A prospective, double-cohort study was performed to assess the clinical course and radiological findings in 12 MS patients presenting associated eosinophilia. All patients presented parasitic infections with positive stool specimens. In all parasite-infected MS patients, the eosinophilia was not present during the 2 previous years. Eosinophil counts were monitored at 3- to 6-month intervals. When counts became elevated, patients were enrolled in the study. Interleukin (IL)-4, IL-10, IL-12, transforming growth factor (TGF)-beta, and interferon-gamma production by myelin basic protein-specific peripheral blood mononuclear cells were studied using enzyme-linked immunospot (ELISPOT). FoxP3 and Smad7 expression were studied by reverse-transcriptase polymerase chain reaction.

RESULTS

During a 4.6-year follow-up period, parasite-infected MS patients showed a significantly lower number of exacerbations, minimal variation in disability scores, as well as fewer magnetic resonance imaging changes when compared with uninfected MS patients. Furthermore, myelin basic protein-specific responses in peripheral blood showed a significant increase in IL-10 and TGF-beta and a decrease in IL-12 and interferon-gamma-secreting cells in infected MS patients compared with noninfected patients. Myelin basic protein-specific T cells cloned from infected subjects were characterized by the absence of IL-2 and IL-4 production, but high IL-10 and/or TGF-beta secretion, showing a cytokine profile similar to the T-cell subsets Tr1 and Th3. Moreover, cloning frequency of CD4+CD25+ FoxP3+ T cells was substantially increased in infected patients compared with uninfected MS subjects. Finally, Smad7 messenger RNA was not detected in T cells from infected MS patients secreting TGF-beta.

INTERPRETATION

Increased production of IL-10 and TGF-beta, together with induction of CD25+CD4+ FoxP3+ T cells, suggests that regulatory T cells induced during parasite infections can alter the course of MS.

Sequential maintenance treatment with glatiramer acetate after mitoxantrone is safe and can limit exposure to immunosuppression in very active, relapsing remitting multiple sclerosis

Mitoxantrone has been approved by the FDA for worsening relapsing remitting and secondary progressive Multiple Sclerosis. However the benefits of this agent in reducing disease progression and relapse rate cannot be sustained in the long-term, as treatment is limited by the potential for cumulative cardiotoxicity. We report our experience utilising Glatiramer Acetate as maintenance immuno-modulatory treatment following initial immunosuppression with Mitoxantrone in a consecutive series of 27 patients with very active relapsing remitting disease, eight of whom had experienced continuing relapse activity on first-line treatment. Duration of treatment with Mitoxantrone and thereby cumulative dose were reduced as our experience with the combination increased.No unanticipated side effects of combination treatment were encountered over a follow-up period of 66 months. A single patient developed therapy related acute leukaemia (TRAL) 9 months after completion of Mitoxantrone.A sustained 90% reduction in annualised relapse rate (p < 0.001) has been observed. Disability is stable or improved in all patients a mean of 36 (16-66) months from initiation of treatment. Early suppression of relapse activity with Mitoxantrone has been maintained at a mean of 22 months from last dose of this agent. Only two relapses have occurred in the cohort since withdrawal of Mitoxantrone, occurring in the two patients who had previously been treated with Glatiramer Acetate. In 9 of the first 10 patients treated, imaged a mean of 27 months after withdrawal of Mitoxantrone, no enhancing lesions were identified on MRI brain scans. Glatiramer Acetate appears a safe and effective option for continuing disease modification in patients with relapsing remitting multiple sclerosis treated with Mitoxantrone. The treatment protocol utilised in later patients in this series appears to have the potential to limit exposure to this agent.

Mitoxantrone versus cyclophosphamide in secondary-progressive multiple sclerosis: a comparative study

Fifty secondary progressive multiple sclerosis (SPMS) patients who had lost one or more EDSS points in the prior two years were selected to receive either cyclophosphamide (25 patients, 13 females, 12 males, F/M = 1.08; mean age: 42.4 years; mean disease duration: 13.3 years; mean EDSS at study entry: 5.7) or mitoxantrone (25 patients, 14 females, 11 males, F/M = 1.27; mean age: 38.2 years; mean disease duration: 11.5 years; mean EDSS at study entry: 5.5). SPMS patients were treated for two years with clinical evaluation (relapse rate, disability progression) every three months and radiological imaging (conventional magnetic resonance imaging) before therapy initiation and at the end of the first and second years of therapy. Safety profile and costs of the two therapeutic protocols were also analysed. In terms of clinical and radiological measures the drugs exerted a quite identical effect on both, and produced a significant reduction in both relapse rate (mitoxantrone Mito): p = 0.001, cyclophosphamide (Cy): p = 0.003) and disability progression (Mito: p = 0.01; Cy: p = 0.01). Subgroups of mitoxantrone- and cyclophosphamide-responding patients were identified (14/25 and 17/25, respectively) and were characterized by a significantly shorter duration of the secondary progressive phase of the disease. In these subgroups, the improvement in the EDSS score at the end of therapy was highly significant (p<0.0001 for Mito, p = 0.0004 for Cy). The safety profiles of both drugs were acceptable; however, the Cy-based therapy protocol was significantly less expensive. We conclude that Cy should be considered as a therapeutic option in rapidly deteriorating SPMS patients.