Intense immunosuppression in patients with rapidly worsening multiple sclerosis: treatment guidelines for the clinician

Cyclodextrin-Containing Drug Delivery Systems and Their Applications in Neurodegenerative Disorders

Cyclodextrins (CDs) are ubiquitous excipients, constituted of cyclic glucopyranose units, and possess a unique dual nature, that of a hydrophobic interior and a hydrophilic exterior. This enables their interaction with lipid-affinitive compounds and hydrophilic compounds, thereby augmenting their application in pharmaceutical formulations as agents for improving solubility, as well as fundamental elements of advanced drug delivery systems. Additionally, CDs, upon suitable modification, can strategically participate in the interaction with cellular components and physical barriers, such as the blood-brain barrier, where their intricate and multifunctional engagement leads to various biological impacts. This review consolidates the crucial features of CDs and their derivatives, and summarizes the applications of them as drug delivery systems in neurodegenerative disorders, emphasizing their notable potentials.

Tolerogenic Lipid Nanoparticles for Delivering Self-Antigen mRNA for the Treatment of Experimental Autoimmune Encephalomyelitis

Multiple sclerosis is a disease caused by autoantigen-responsive immune cells that disrupt the myelin in the central nervous system (CNS). Although immunosuppressive drugs are used to suppress symptoms, no definitive therapy exists. As in the experimental autoimmune encephalitis (EAE) model of multiple sclerosis, a partial sequence of the myelin oligodendrocyte glycoprotein (MOG35-55) was identified as a causative autoantigen. This suggests that the induction of immune tolerance that is specific to MOG35-55 would be a fundamental treatment for EAE. We previously reported that lipid nanoparticles (LNPs) containing an anionic phospholipid, phosphatidylserine (PS), in their lipid composition, can be used to deliver mRNA and that this leads to proteins of interest to be expressed in the spleen. In addition to the targeting capability of PS, PS molecules avoid activating the immune system. Physiologically, the recognition of PS on apoptotic cells suppresses immune activation against these cells by releasing cytokines, such as interleukin-10 (IL-10) and transforming growth factor (TGF)-β that negatively regulate immunity. In this study, we tested whether mRNA delivery of autoantigens to the spleen by PS-LNPs causes the expression of MOG35-55 antigens with minimal immune stimulation and whether this could be used to treat an EAE model by inducing immune tolerance.

Exploiting Rational Assembly to Map Distinct Roles of Regulatory Cues during Autoimmune Therapy

Autoimmune diseases like multiple sclerosis (MS), type 1 diabetes, and lupus occur when the immune system attacks host tissue. Immunotherapies that promote selective tolerance without suppressing normal immune function are of tremendous interest. Here, nanotechnology was used for rational assembly of peptides and modulatory immune cues into immune complexes. Complexes containing self-peptides and regulatory nucleic acids reverse established paralysis in a preclinical MS model. Importantly, mice responding to immunotherapy maintain healthy, antigen-specific B and T cell responses during a foreign antigen challenge. A therapeutic library isolating specific components reveals that regulatory nucleic acids suppress inflammatory genes in innate immune cells, while disease-matched peptide sequences control specificity of tolerance. Distinct gene expression profiles in cells and animals are associated with the immune signals administered in particulate and soluble forms, highlighting the impact of biophysical presentation of signals. This work provides insight into the rational manipulation of immune signaling to drive tolerance.

Autoantigen Tetramer Silences Autoreactive B Cell Populations

Many autoimmune therapies focus on immune suppression to reduce symptom severity and halt disease progression; however, currently approved treatments lack specificity for the autoantigen and rely on more global immune suppression. Multivalent antigen arrays can disarm pathogenic autoimmune B cell populations that specifically recognize the antigen of interest via their B cell receptor (BCR). Disarmament may be achieved by BCR engagement, cross-linking, and sustained receptor occupancy as a result of multivalent, high avidity BCR binding. To engage and explore this mechanism, a tetramer display of the encephalogenic proteolipid peptide (PLP_139-151), referred to as 4-arm PLP_139-151, was synthesized by copper-catalyzed azide-alkyne cycloaddition chemistry. Subcutaneous administration of 4-arm PLP_139-151 completely ameliorated symptoms of paralysis in a mouse model of multiple sclerosis known as experimental autoimmune encephalomyelitis. Competitive binding of 4-arm PLP_139-151 to PLP_139-151-specific IgG in the mouse serum demonstrated the enhanced avidity associated with the multivalent array compared to the free peptide. Furthermore, key PLP_139-151-reactive B cells were depleted following 4-arm PLP_139-151 treatment, resulting in significant reduction of proinflammatory cytokines. Together, these data demonstrate the potential of 4-arm PLP_139-151 to silence autoreactive B cell populations and limit the downstream activation of effector cells.

Modulating lung immune cells by pulmonary delivery of antigen-specific nanoparticles to treat autoimmune disease

Antigen-specific particles can treat autoimmunity, and pulmonary delivery may provide for easier delivery than intravenous or subcutaneous routes. The lung is a "hub" for autoimmunity where autoreactive T cells pass before arriving at disease sites. Here, we report that targeting lung antigen-presenting cells (APCs) via antigen-loaded poly(lactide-co-glycolide) particles modulates lung CD4+ T cells to tolerize murine experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Particles directly delivered to the lung via intratracheal administration demonstrated more substantial reduction in EAE severity when compared with particles delivered to the liver and spleen via intravenous administration. Intratracheally delivered particles were associated with lung APCs and decreased costimulatory molecule expression on the APCs, which inhibited CD4+ T cell proliferation and reduced their population in the central nervous system while increasing them in the lung. This study supports noninvasive pulmonary particle delivery, such as inhalable administration, to treat autoimmune disease.

Design of biodegradable nanoparticles to modulate phenotypes of antigen-presenting cells for antigen-specific treatment of autoimmune disease

Current therapeutic options for autoimmune diseases, such as multiple sclerosis (MS), often require lifelong treatment with immunosuppressive drugs, yet strategies for antigen-specific immunomodulation are emerging. Biodegradable particles loaded with disease-specific antigen, either alone or with immunomodulators, have been reported to ameliorate disease. Herein, we hypothesized that the carrier could impact polarization of the immune cells that associate with particles and the subsequent disease progression. Single injection of three polymeric carriers, 50:50 poly (DL-lactide-co-glycolide) (PLG) with two molecular weights (Low, High) and poly (DL-lactide) (PLA), loaded with the disease-specific antigen, proteolipid protein (PLP_139-151), were investigated for the ability to attenuate clinical scores in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. At a low particle dose, mice treated with PLA-based particles had significantly lower clinical scores at the chronic stage of the disease over 200 days post immunization, while neither PLG-based particles nor OVA control particles reduced the clinical scores. Compared to PLG-based particles, PLA-based particles were largely associated with Kupffer cells and liver sinusoidal endothelial cells, which had a reduced co-stimulatory molecule expression that correlated with a reduction of CD4⁺ T-cell populations in the central nervous system. Delivery of PLA-based particles encapsulated with higher levels of PLP_139-151 at a reduced dose were able to completely ameliorate EAE over 200 days along with inhibition of Th1 and Th17 polarization. Collectively, our study demonstrates that the carrier properties and antigen loading determine phenotypes of immune cells in the peripheral organs, influencing the amelioration of both acute and chronic stages of autoimmunity.

Effects of multiple sclerosis disease-modifying therapies on employment measures using patient-reported data

BACKGROUND

The direct comparative evidence on treatment effects of available multiple sclerosis (MS) disease-modifying therapies (DMTs) is limited, and few studies have examined the benefits of DMTs on employment outcomes. We compared the effects of DMTs used in the previous 5 years on improving the work attendance, amount of work and work productivity of people with MS.

METHODS

The Australian MS Longitudinal Study collected data from participants on DMTs usage from 2010 to 2015 and whether DMTs contributed to changes in employment outcomes. We classified 11 DMTs into three categories based on their clinical efficacy (β-interferons and glatiramer acetate as category 1; teriflunomide and dimethyl fumarate as category 2; fingolimod, natalizumab, alemtuzumab and mitoxantrone as category 3). Each DMT used by a participant was treated as one observation and analysed by log-multinomial regression.

RESULTS

Of the 874 participants included, 1384 observations were generated. Those who used category 3 (higher efficacy) DMTs were 2-3 times more likely to report improvements in amount of work, work attendance and work productivity compared with those who used category 1 (classical injectable) DMTs. Natalizumab was associated with superior beneficial effects on patient-reported employment outcomes than fingolimod (RR=1.76, 95% CI 1.02 to 3.03 for increased work attendance and RR=1.46, 95% CI 1.02 to 2.10 for increased work productivity).

CONCLUSIONS

Those using the higher efficacy (category 3) DMTs, particularly fingolimod and natalizumab, reported significant increases in amount of work, work attendance and work productivity, suggesting they have important beneficial effects on work life in people with MS.

Peptide-Conjugated Nanoparticles Reduce Positive Co-stimulatory Expression and T Cell Activity to Induce Tolerance

Targeted approaches to treat autoimmune diseases would improve upon current therapies that broadly suppress the immune system and lead to detrimental side effects. Antigen-specific tolerance was induced using poly(lactide-co-glycolide) nanoparticles conjugated with disease-relevant antigen to treat a model of multiple sclerosis. Increasing the nanoparticle dose and amount of conjugated antigen both resulted in more durable immune tolerance. To identify active tolerance mechanisms, we investigated downstream cellular and molecular events following nanoparticle internalization by antigen-presenting cells. The initial cell response to nanoparticles indicated suppression of inflammatory signaling pathways. Direct and functional measurement of surface MHC-restricted antigen showed positive correlation with both increasing particle dose from 1 to 100 μg/mL and increasing peptide conjugation by 2-fold. Co-stimulatory analysis of cells expressing MHC-restricted antigen revealed most significant decreases in positive co-stimulatory molecules (CD86, CD80, and CD40) following high doses of nanoparticles with higher peptide conjugation, whereas expression of a negative co-stimulatory molecule (PD-L1) remained high. T cells isolated from mice immunized against myelin proteolipid protein (PLP139-151) were co-cultured with antigen-presenting cells administered PLP139-151-conjugated nanoparticles, which resulted in reduced T cell proliferation, increased T cell apoptosis, and a stronger anti-inflammatory response. These findings indicate several potential mechanisms used by peptide-conjugated nanoparticles to induce antigen-specific tolerance.

Clinical Application of Autologous Adipose Stem Cells in Patients with Multiple Sclerosis: Preliminary Results

The clinical outcome of autologous adipose stem cell (ASC) treatment of patients with multiple sclerosis (MS) was investigated following one year of observation. Methods. The clinical and MRI outcomes of 16 ASC-treated patients with RRMS and SPMS are reported after a one-year follow-up period. Results. At 18 months of follow-up, some patients showed “enticing” improvements on some exploratory efficacy measures, although a significant benefit was not observed for any measure across the entire group. Neither the progression of disability nor relapses were observed in any cases. In four patients, we found new gadolinium+ (Gd+) lesions on MRI. Our results indicate that ASC therapy is safe and does not produce any substantial side effects. Disease progression-free survival (PFS) of 18 months was seen in all patients with RRMS and SPMS. In these patients, EDSS scores did not progress above baseline scores. Gd-enhancing lesions were observed in two cases with RRMS, but these patients did not exhibit changes in EDSS score. Conclusion. Intrathecal treatment with ASCs is an attractive form of therapy for patients with MS but should be reserved for cases with aggressive disease progression, for cases that are still in the inflammatory phase, and for the malignant form.

[Infection risks in multiple sclerosis therapy by infusion of disease modifying drugs]

The increased risk of developing infections when using disease-modifying drugs for treatment of multiple sclerosis (MS) is a major challenge in the daily clinical routine. In the growing field of treatment options specific knowledge of treatment-related risks of infections and appropriate preventive and countermeasures is mandatory. Current clinical experience shows that an individual risk stratification is necessary when choosing treatment options and while monitoring during and after treatment administration. The determination of the individual risk of infection in the context of serial use of disease-modifying drugs remains a challenging issue. In addition to the mechanisms of action, the warning notices and current recommendations on infection prophylaxis when using intravenous disease-modifying drugs, such as alemtuzumab, natalizumab and mitoxantron, are presented in detail.

Intranasal delivery of stem cells as therapy for central nervous system disease

Stem cells, upon entering the CNS, can preferentially migrate into disease foci, where they exert therapeutic effects that compensate for lost tissue, reconstructing damaged neuronal circuitry and establishing in the brain a new microenvironment suitable for cell survival. However, the route of stem cell delivery into the CNS remains a challenge: with systemic administration (e.g., intravenous injection), a fraction of cells may be trapped in other organs than the CNS, while direct CNS injections, e.g., intracerebroventricular or transcranial, are invasive. Intranasal (i.n.) delivery of stem cells, in contrast, can effectively bypass the blood-brain barrier, rapidly enter the CNS, and minimize systemic distribution. I.n. delivery of stem cells may therefore be a safe and non-invasive way of targeting the CNS and would thus be a promising therapeutic option for CNS disease. In this review we discuss the i.n. route for stem cell delivery into the CNS, and the perspectives of i.n. stem cell-based therapy in CNS disease.

Systematic review of clinical practice guidelines related to multiple sclerosis

Background

High quality clinical practice guidelines (CPGs) can provide clinicians with explicit recommendations on how to manage health conditions and bridge the gap between research and clinical practice. Unfortunately, the quality of CPGs for multiple sclerosis (MS) has not been evaluated.

Objective

To evaluate the methodological quality of CPGs on MS using the AGREE II instrument.

Methods

According to the inclusion and exclusion criteria, we searched four databases and two websites related to CPGs, including the Cochrane library, PubMed, EMBASE, DynaMed, the National Guideline Clearinghouse (NGC), and Chinese Biomedical Literature database (CBM). The searches were performed on September 20th 2013. All CPGs on MS were evaluated by the AGREE II instrument. The software used for analysis was SPSS 17.0.

Results

A total of 27 CPGs on MS met inclusion criteria. The overall agreement among reviews was good or substantial (ICC was above 0.70). The mean scores for each of all six domains were presented as follows: scope and purpose (mean ± SD: 59.05±16.13), stakeholder involvement (mean ± SD: 29.53±17.67), rigor of development (mean ± SD: 31.52±21.50), clarity of presentation (mean ± SD: 60.39±13.73), applicability (mean ± SD: 27.08±17.66), editorial independence (mean ± SD: 28.70±22.03).

Conclusions

The methodological quality of CPGs for MS was acceptable for scope, purpose and clarity of presentation. The developers of CPGs need to pay more attention to editorial independence, applicability, rigor of development and stakeholder involvement during the development process. The AGREE II instrument should be adopted by guideline developers.

Multiple sclerosis treatment and infectious issues: update 2013

Immunomodulation and immunosuppression are generally linked to an increased risk of infection. In the growing field of new and potent drugs for multiple sclerosis (MS), we review the current data concerning infections and prevention of infectious diseases. This is of importance for recently licensed and future MS treatment options, but also for long-term established therapies for MS. Some of the disease-modifying therapies (DMT) go along with threats of specific severe infections or complications, which require a more intensive long-term monitoring and multi-disciplinary surveillance. We update the existing warning notices and infectious issues which have to be considered using drugs for multiple sclerosis.

Folate receptor-targeted aminopterin therapy is highly effective and specific in experimental models of autoimmune uveitis and autoimmune encephalomyelitis

EC0746 is a rationally designed anti-inflammatory drug conjugate consisting of a modified folic acid-based ligand linked to a γ-hydrazide analog of aminopterin. In this report, EC0746's effectiveness was evaluated against experimental retinal S-antigen (PDSAg) induced autoimmune uveitis (EAU) and myelin-basic-protein induced autoimmune encephalomyelitis (EAE). In both models, functional FR-β was detected on activated macrophages in local (retinal or central-nervous-system, respectively) and systemic (peritoneal cavity) sites of inflammation. In myelin-rich regions of EAE rats, an increased uptake of (99m)Tc-EC20 (etarfolatide; a FR-specific radioimaging agent) was also observed. EC0746 treatment at disease onset suppressed the clinical severity of both EAU and EAE, and it strongly attenuated progressive histopathological changes in the affected organs. In all parameters assessed, EC0746 activity was completely blocked by a benign folate competitor, suggesting that these therapeutic outcomes were specifically FR-β mediated. EC0746 may emerge as a useful macrophage-modulating agent for treating inflammatory episodes of organ-specific autoimmunity.

Risk-benefit considerations in the treatment of relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system and mainly affects young adults. Its natural history has changed in recent years with the advent of disease-modifying drugs, which have been available since the early 1990s. The increasing number of first-line and second-line treatment options, together with the variable course of the disease and patient lifestyles and expectations, makes the therapeutic decision a real challenge. The aim of this review is to give a comprehensive overview of the main present and some future drugs for relapsing-remitting MS, including risk-benefit considerations, to enable readers to draw their own conclusions regarding the risk-benefit assessment of personalized treatment strategies, taking into account not only treatment-related but also disease-related risks. We performed a Medline literature search to identify studies on the treatment of MS with risk stratification and risk-benefit considerations. We focused our attention on studies of disease-modifying, immunomodulating, and immunosuppressive drugs, including monoclonal antibodies. Here we offer personal considerations, stemming from long-term experience in the treatment of MS and thorough discussions with other neurologists closely involved in the care of patients with the disease. MS specialists need to know not only the specific risks and benefits of single drugs, but also about drug interactions, either in simultaneous or serial combination therapy, and patient comorbidities, preferences, and fears. This has to be put into perspective, considering also the risks of untreated disease in patients with different clinical and radiological characteristics. There is no single best treatment strategy, but therapy has to be tailored to the patient. This is a time-consuming task, rich in complexity, and influenced by the attitude towards risk on the parts of both the patient and the clinical team. The broader the MS drug market becomes, the harder it will be for the clinician to help the patient decide which therapeutic strategy to opt for.

[Update on diagnosis and treatment of multiple sclerosis]

Recent advances in neuroimaging have simplified the diagnostic criteria of multiple sclerosis. Indeed, the diagnosis of multiple sclerosis could be obtained during the first bout of disease flare, very early in the disease course. This is particularly important to shorten the diagnostic delay as early treatment may limit the occurrence of late irreversible disabilities. At the same time, major therapeutic advances have been obtained and new drugs that are well tolerated and more effective, despite the possible rare but potentially severe side effects are been developed. This article reviews the modern diagnostic and therapeutic strategies in multiple sclerosis in accordance with the recent obtained advances.

Microglia and monocyte-derived macrophages: functionally distinct populations that act in concert in CNS plasticity and repair

Functional macrophage heterogeneity is recognized outside the central nervous system (CNS), where alternatively activated macrophages can perform immune-resolving functions. Such functional heterogeneity was largely ignored in the CNS, with respect to the resident microglia and the myeloid-derived cells recruited from the blood following injury or disease, previously defined as blood-derived microglia; both were indistinguishably perceived detrimental. Our studies have led us to view the myeloid-derived infiltrating cells as functionally distinct from the resident microglia, and accordingly, to name them monocyte-derived macrophages (mo-MΦ). Although microglia perform various maintenance and protective roles, under certain conditions when they can no longer provide protection, mo-MΦ are recruited to the damaged CNS; there, they act not as microglial replacements but rather assistant cells, providing activities that cannot be timely performed by the resident cells. Here, we focus on the functional heterogeneity of microglia/mo-MΦ, emphasizing that, as opposed to the mo-MΦ, microglia often fail to timely acquire the phenotype essential for CNS repair.

Clinical effects of natalizumab on multiple sclerosis appear early in treatment course

In clinical practice natalizumab is typically used in patients who have experienced breakthrough disease during treatment with interferon beta (IFNβ) or glatiramer acetate. In these patients it is important to reduce disease activity as quickly as possible. In a phase II study, differences between natalizumab and placebo in MRI outcomes reflecting inflammatory activity were evident after the first infusion and maintained through a 6-month period, suggesting a rapid onset of natalizumab treatment effects. To explore how soon after natalizumab initiation clinical effects become apparent, annualized relapse rates per 3-month period and time to first relapse were analyzed in the phase III AFFIRM study (natalizumab vs. placebo) and in the multinational Tysabri^® Observational Program (TOP). In AFFIRM, natalizumab reduced the annualized relapse rate within 3 months of treatment initiation compared with placebo in the overall population (0.30 vs. 0.71; p < 0.0001) and in patients with highly active disease (0.30 vs. 0.94; p = 0.0039). The low annualized relapse rate was maintained throughout the 2-year study period, and the risk of relapse in AFFIRM patients treated with natalizumab was reduced [hazard ratio against placebo 0.42 (95 % CI 0.34–0.52); p < 0.0001]. Rapid reductions in annualized relapse rate also occurred in TOP (baseline 1.99 vs. 0–3 months 0.26; p < 0.0001). Natalizumab resulted in rapid, sustained reductions in disease activity in both AFFIRM and in clinical practice. This decrease in disease activity occurred within the first 3 months of treatment even in patients with more active disease.

Human T cell expansion and experimental autoimmune encephalomyelitis inhibited by Lenaldekar, a small molecule discovered in a zebrafish screen

Immune-mediated diseases [multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE)] are driven by proliferating, highly activated autoreactive T-cells that are unresponsive to in vivo immunoregulatory mechanisms. The compound Lenaldekar (LDK) was identified in a zebrafish screen by inhibiting T-cell expansion. By monitoring mitogen- and antigen-driven proliferation, we found that LDK inhibited human and murine T-cell expansion in a non-cytolytic manner. This suppressive activity directly correlated with the degree of activation/proliferation of the T-cells. In testing LDK in an EAE model of MS, exacerbations were suppressed in treated animals. Therefore, LDK represents a novel therapeutic approach to T-cell-mediated autoimmune diseases.

No increase in cancer incidence detected after cyclophosphamide in a French cohort of patients with progressive multiple sclerosis

BACKGROUND

Cyclophosphamide is still used in progressive forms of multiple sclerosis (MS) in view of its suggested efficacy and safety in the short term. No data exist on its long-term safety in MS, particularly on the risk of malignancy.

OBJECTIVE

The objective of this study was to evaluate cancer incidence in MS after cyclophosphamide treatment.

METHODS

We performed a historical prospective study in a cohort of MS patients treated with cyclophosphamide. We collected demographic data and medical history from medical databases and patient interviews. Reported cancers were histologically confirmed. Cancer incidence was compared with the incidence in the general population by estimating standardized incidence ratios (SIRs).

RESULTS

We included 354 patients, with a median follow-up of 5 years (range 2-15) after cyclophosphamide treatment. Fifteen patients developed a solid cancer, which occurred at a median of 3 years (range 0.5-14) after cyclophosphamide introduction. The cumulative incidence of cancer after cyclophosphamide was 3.1% at 5 years and 5.9% at 8 years. We found no increase in cancer incidence after cyclophosphamide treatment in men (SIR = 0.83, 95% confidence interval [CI] 0.30-1.82), women (SIR = 0.99, 95% CI 0.43-1.95), or men and women combined (SIR = 0.92, 95% CI 0.50-1.54).

CONCLUSION

We found no evidence of an increased risk of cancer associated with cyclophosphamide treatment in MS patients.

A one-year prospective, randomized, placebo-controlled, quadruple-blinded, phase II safety pilot trial of combination therapy with interferon beta-1a and mycophenolate mofetil in early relapsing-remitting multiple sclerosis (TIME MS)

BACKGROUND

Mycophenolate mofetil (MMF) is an oral DNA base synthesis inhibitor with immunomodulatory effects on B cells, T cells, and macrophages.

OBJECTIVE

To conduct a safety and tolerability pilot study of interferon beta-1a (IFN-b1a) in combination with either placebo or oral MMF in multiple sclerosis (MS).

METHODS

Twenty-four treatment-naïve R-RMS patients participated in a one-year prospective, placebo-controlled, blinded, safety pilot clinical trial. Every patient injected weekly intramuscular interferon beta-1a. The cohort was then randomized (1 : 1) to either active oral MMF or identical-appearing placebo tablets. Clinical evaluations were assessed every 3 months, along with brain MRI scans performed at baseline and repeated every 60 days for one year. Comprehensive laboratory assessments were monitored for safety, along with adverse events.

RESULTS

In this small pilot investigation, no differences were identified between the two treatment groups with respect to patient-reported adverse events, MRI metrics, or laboratory abnormalities. Notwithstanding these observations, and the limited number of patients treated, trends appeared to favor the combination therapy regimen.

CONCLUSIONS

The combination treatment regimen of interferon beta-1a and MMF appeared to be well tolerated in this pilot study. Despite the small sample size, therapeutic trends were observed in favor of combination therapy. An adequately powered controlled trial of MMF in MS appears warranted.

Escalating immunotherapy of multiple sclerosis

Basic disease-modifying treatment for relapsing forms of active multiple sclerosis (MS) is now available in many countries with high prevalence rates, for this chronic inflammatory disease of the central nervous system. Several lines of evidence support early immunomodulatory treatment with either recombinant interferon-beta or glatiramer acetate, and positive results from phase III trials encourage start of treatment even in patients with clinically isolated syndromes (CIS). However, currently available drugs for basic therapy are only partially effective and patients may still encounter relapses or disease progression. As treatment-refractory, clinically active MS can quickly lead to irreversible neurological disability there is an urgent need for effective escalating strategies. Patients with suboptimal treatment response to basic therapy have been treated with combination therapies, cytotoxic drugs (such as mitoxantrone and cyclophosphamide) or autologous hematopoietic stem cell transplantation. Recently, the monoclonal antibody, natalizumab, was added to this armamentarium. None of these strategies have been vigorously evaluated in large randomized, controlled phase III trials with patients who failed basic therapy. Therefore, the decision to escalate immunotherapy is still based on limited evidence. This article will review potential candidates for intensified immunosuppression and call for innovative study designs to better evaluate escalating immunotherapy in 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.

Lights and shadows of cyclophosphamide in the treatment of multiple sclerosis

Cyclophosphamide (cy) is an alkylating agent used to treat malignancies and immune-mediated inflammatory nonmalignant processes. It has been used as a treatment in cases of worsening multiple sclerosis (MS). Cy is currently used for patients whose disease is not controlled by beta-interferon or glatiramer acetate as well as those with rapidly worsening MS. The most commonly used regimens involve outpatient IV pulse therapy given with or without corticosteroids every 4 to 8 weeks. Side effects include nausea, headache, alopecia, pain, male and women infertility, bladder toxicity, and risk of malignancy. Previous studies suggest that cy is effective in patients in the earlier stages of disease, where inflammation predominates over degenerative processes. Given that early inflammatory events appear to correlate with later disability, a major question is whether strong anti-inflammatory drugs, such as cy, will have an impact on later degenerative changes if given early in the disease to halt inflammation.

3G11 expression in CD4+ T cell-mediated autoimmunity and immune tolerance

3G11 is a sialylated carbohydrate epitope of the disialoganglioside molecule expressed on mouse CD4(+) T cells. Recent research showed that 3G11 expression is related to the modulation of T cell function, i.e., 3G11(-) T cells exhibit anergic/Treg characteristics and efficiently inhibit autoimmunity in the central nervous system. The relationship between 3G11 expression and immune tolerance is summarized in this literature review.

Evaluation of bone marrow- and brain-derived neural stem cells in therapy of central nervous system autoimmunity

Adult subventricular zone (SVZ)-derived neural stem cells (NSCs) have therapeutic effects in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. However, SVZ precursor cells as a source of NSCs are not readily accessible for clinical application. In the present study, we demonstrate that NSCs derived from bone marrow (BM) cells exhibit comparable morphological properties as those derived from SVZ cells and possess a similar ability to differentiate into neurons, astrocytes, and oligodendrocytes both in vitro and in vivo. Importantly, both types of NSCs suppressed chronic experimental autoimmune encephalomyelitis to a comparable extent on transplantation. Mechanisms underlying the therapeutic effects of NSCs include immunomodulation in the periphery and the central nervous system (CNS), neuron/oligodendrocyte repopulation by transplanted cells, and enhanced endogenous remyelination and axonal recovery. Furthermore, we provide evidence for the trans-differentiation of transplanted BM-NSCs into neural cells in the CNS, while no fusion of these cells with host neural cells was detected. This is the first study that directly compares SVZ- versus BM-NSCs with regard to in vivo neural differentiation and anti-inflammatory and therapeutic effects on CNS inflammatory demyelination. Their virtually identical therapeutic potential, greater accessibility, and autologous properties make BM-NSCs a novel and highly applicable substitute for SVZ-NSCs in cell-based multiple sclerosis therapies.

Therapy of multiple sclerosis in children and adolescents

BACKGROUND

Paediatric multiple sclerosis accounts for up to 10% of all MS cases. The initial course of the disease is relapsing-remitting in most children, with a relapse rate generally higher than that observed in adult patients. There is published experience on the use of first-line disease modifying therapies in children with MS. However, about 1/3 of paediatric MS cases do not respond to IFN-beta or glatiramer acetate and continue to develop relapses and disease progression. These patients could be proposed to a second-line treatment.

METHODS

A comprehensive review of the published literature related to pharmacologic treatment of MS in adults and paediatric patients was performed. The recent literature has been extracted for new evidence from controlled trials in adult patients, and open treatment studies and reported expert opinion in paediatric patients.

RESULTS

No disease modifying drug has been approved for the treatment of children and adolescents with MS, although the currently available first-line therapies for adults seem to be safe and well tolerated in this population. Further studies are required to assess the safety and efficacy of second-line treatments in children with MS.

CONCLUSION

The present article constitutes an update of the existing publications regarding treatment of acute events of CNS demyelination in children and adolescents as well as considerations for the use of immunomodulatory therapies.

Characteristics of multiple sclerosis at onset and delay of diagnosis and treatment in Spain (the Novo Study)

Multiple sclerosis (MS) is a disease supposedly of autoimmune origin, with reactivity directed against myelin antigens. From the neuropathological point of view, MS produces inflammation, demyelination and axonal and neuronal degeneration. Inflammatory phenomena are predominant in the initial phase of the disease, followed later by neurodegenerative processes. Over the last decade, early treatment, during the most inflammatory phase of the disease, has been considered the best strategy to treat MS. Accordingly, we decided to determine the periods of delay between the first symptoms and the time to the first medical visit, the time to referral to a specialised MS unit, the delay in undertaking clinical and paraclinical tests, the diagnostic criteria used and the overall delay in diagnosis and treatment. The median time from onset of first symptoms to the first visit to a physician was 19.2 months, which represented the greatest delay. The median time between this initial medical consultation and the confirmation of the diagnosis by a specialised MS unit was 5.7 months, and the overall time from symptom onset to diagnosis was 24.9 months (2.08 years). The median time between onset of the first symptoms and the decision to give the first treatment was 2 years. The most important delay was that from symptom onset to the first medical visit, with the other delays being less. Thus, it is during this initial period that greater effort is required in order to reduce the time to diagnosis, by increasing awareness of the problem of MS among the general population and primary care physicians.

Variable effects of cyclophosphamide in rodent models of experimental allergic encephalomyelitis

In this study, we have evaluated the effects of cyclophosphamide on the development of experimental allergic encephalomyelitis (EAE) in four EAE rodent models: monophasic EAE in Lewis rats, protracted relapsing (PR)-EAE in DA rats, myelin oligodendrocyte protein (MOG)-induced EAE in C57Bl/6 mice and proteolipid protein (PLP)-induced EAE in Swiss/Jackson Laboratory (SJL) mice. Cyclophosphamide, administered either prophylactically or therapeutically, suppressed most strongly the clinical symptoms of PR-EAE in DA rats. Treated rats in this group also exhibited the lowest degree of inflammatory infiltration of the spinal cord, as well as the lowest levels of nuclear factor kappa B, interleukin-12 and interferon-gamma. Cyclophosphamide prophylactically, but not therapeutically, also delayed significantly the onset of EAE in Lewis rats. In contrast, regardless of the treatment regimen used, was unable to influence the clinical course of EAE in either MOG-induced EAE in C57Bl/6 mice or PLP-induced EAE in SJL mice. This heterogeneous pharmacological response to cyclophosphamide suggests that significant immunopathogenic differences exist among these EAE rodent models that must be considered when designing preclinical studies. In addition, the effectiveness of cyclophosphamide in dark Agouti (DA) rats with PR-EAE suggests that this may be a particularly useful model for studying novel therapeutic approaches for refractory and rapidly worsening multiple sclerosis in human patients.

Neurodegenerative disorders and nanoformulated drug development

Degenerative and inflammatory diseases of the CNS include, but are not limited to, Alzheimer's and Parkinson's disease, amyotrophic lateral sclerosis, stroke, multiple sclerosis and HIV-1-associated neurocognitive disorders. These are common, debilitating and, unfortunately, hold few therapeutic options. In recent years, the application of nanotechnologies as commonly used or developing medicines has served to improve pharmacokinetics and drug delivery specifically to CNS-diseased areas. In addition, nanomedical advances are leading to therapies that target CNS pathobiology and as such, can interrupt disordered protein aggregation, deliver functional neuroprotective proteins and alter the oxidant state of affected neural tissues. This article focuses on the pathobiology of common neurodegenerative disorders with a view towards how nanomedicine may be used to improve the clinical course of neurodegenerative disorders.

ABC-transporter gene-polymorphisms are potential pharmacogenetic markers for mitoxantrone response in multiple sclerosis

Escalation therapy with mitoxantrone (MX) in highly active multiple sclerosis is limited by partially dose-dependent side-effects. Predictors of therapeutic response may result in individualized risk stratification and MX dosing. ATP-binding cassette-transporters ABCB1 and ABCG2 represent multi-drug resistance mechanisms involved in active cellular MX efflux. Here, we investigated the role of ABC-gene single nucleotide polymorphisms (SNPs) for clinical MX response, corroborated by experimental in vitro and in vivo data. Frequencies of ABCB1 2677G>T, 3435C>T and five ABCG2-SNPs were analysed in 832 multiple sclerosis patients (Germany, Spain) and 264 healthy donors. Using a flow-cytometry-based in vitro assay, MX efflux in leukocytes from individuals with variant alleles in both ABC-genes (designated genotype ABCB1/ABCG2-L(ow), 22.2% of patients) was 37.7% lower than from individuals homozygous for common alleles (ABCB1/ABCG2-H(igh), P < 0.05, 14.8% of patients), resulting in genotype-dependent MX accumulation and cell death. Addition of glucocorticosteroids (GCs) inhibited MX efflux in vitro. ABC-transporters were highly expressed in leukocyte subsets, glial and neuronal cells as well as myocardium, i.e. cells/tissues potentially affected by MX therapy. In vivo significance was further corroborated in experimental autoimmune encephalomyelitis in Abcg2(-/-) animals. Using a MX dose titrated to be ineffective in wild-type animals, disease course and histopathology in Abcg2(-/-) mice were strongly ameliorated. Retrospective clinical analysis in MX monotherapy patients (n = 155) used expanded disability status scale, relapse rate and multiple sclerosis functional composite as major outcome parameters. The clinical response rate [overall 121 of 155 patients (78.1%)] increased significantly with genotypes associated with decreasing ABCB1/ABCG2-function [ABCB1/ABCG2-H 15/24 (62.5%) responders, ABCB1/ABCG2-I(ntermediate) 78/98 (79.6%), ABCB1/ABCG2-L 28/33 (84.8%), exact Cochran-Armitage test P = 0.039]. The odds ratio for response was 1.9 (95% CI 1.0-3.5) with each increase in ABCB1/ABCG2 score (from ABCB1/ABCG2-H to -I-, and -I to -L). In 36 patients with severe cardiac or haematological side effects no statistically relevant difference in genotype frequency was observed. However, one patient with biopsy proven cardiomyopathy only after 24 mg/m2 MX exhibited a rare genotype with variant, partly homozygous alleles in 3 ABC-transporter genes. In conclusion, SNPs in ABC-transporter genes may serve as pharmacogenetic markers associated with clinical response to MX therapy in multiple sclerosis. Combined MX/GC-treatment warrants further investigation.

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.

Multiple sclerosis

Multiple sclerosis is the most common disabling neurologic disease affecting young adults and adolescents in the United States. The first objective of this article is to familiarize nonspecialists with the cardinal features of multiple sclerosis and our current understanding of its etiology, epidemiology, and natural history. The second objective is to explain the approach to diagnosis. The third is to clarify current evidence-based treatment strategies and their roles in disease modification. The overall goal is to facilitate the timely evaluation and confirmation of diagnosis and enhance effective management through collaboration among primary physicians, neurologists, and other care providers who are confronted with these formidably challenging patients.

Disease-modifying agents for multiple sclerosis: recent advances and future prospects

Multiple sclerosis (MS) is a chronic autoimmune disease of the CNS. Currently, six medications are approved for immunmodulatory and immunosuppressive treatment of the relapsing disease course and secondary-progressive MS. In the first part of this review, the pathogenesis of MS and its current treatment options are discussed. During the last decade, our understanding of autoimmunity and the pathogenesis of MS has advanced substantially. This has led to the development of a number of compounds, several of which are currently undergoing clinical testing in phase II and III studies. While current treatment options are only available for parenteral administration, several oral compounds are now in clinical trials, including the immunosuppressive agents cladribine and laquinimod. A novel mode of action has been described for fingolimod, another orally available agent, which inhibits egress of activated lymphocytes from draining lymph nodes. Dimethylfumarate exhibits immunomodulatory as well as immunosuppressive activity when given orally. All of these compounds have successfully shown efficacy, at least in regards to the surrogate marker contrast-enhancing lesions on magnetic resonance imaging. Another class of agents that is highlighted in this review are biological agents, namely monoclonal antibodies (mAb) and recombinant fusion proteins. The humanized mAb daclizumab inhibits T-lymphocyte activation via blockade of the interleukin-2 receptor. Alemtuzumab and rituximab deplete leukocytes and B cells, respectively; the fusion protein atacicept inhibits specific B-cell growth factors resulting in reductions in B-cells and plasma cells. These compounds are currently being tested in phase II and III studies in patients with relapsing MS. The concept of neuro-protection and -regeneration has not advanced to a level where specific compounds have entered clinical testing. However, several agents approved for conditions other than MS are highlighted. Finally, with the advent of these highly potent novel therapies, rare, but potentially serious adverse effects have been noted, namely infections and malignancies. These are critically reviewed and put into perspective.

Fumarates for the treatment of multiple sclerosis: potential mechanisms of action and clinical studies

All licensed disease-modifying drugs for the treatment of relapsing-remitting multiple sclerosis (MS) only display partial efficacy and hitherto require parenteral administration. Thus, there is a high demand for innovative and at the same time orally available MS therapeutics. Fumaric acids and their esters (FAE) may represent such a new class of compounds. FAE display immunomodulatory properties and may also exert neuroprotective effects, as shown in vitro as well as in experimental models of MS. A first Phase II study with the new, modified FAE BG00012/FAG-201 (BG-12) in relapsing-remitting MS revealed significant effects on MRI parameters such as gadolinium-enhancing lesions, T1 hypointense lesions and T2 lesion load after 24 weeks of treatment. The trial also underlined the safety and good tolerability of FAE that are already in clinical use for the systemic treatment of severe psoriasis. Presently, two Phase III studies are ongoing to investigate the clinical long-term efficacy of BG-12. In summary, FAE are potential candidates that may open a new therapeutic option for relapsing-remitting MS in the near future.

Analysis of cerebrospinal fluid and cerebrospinal fluid cells from patients with multiple sclerosis for detection of JC virus DNA

OBJECTIVE

1) To determine whether JC virus (JCV) DNA was present in the cerebrospinal fluid (CSF) and blood from patients with multiple sclerosis (MS) in comparison with controls and 2) to find out if our clinical material, based on presence of JCV DNA, included any patient at risk for progressive multifocal leukoencephalopathy (PML).

METHODS

The prevalence of JCV DNA was analyzed in CSF and plasma from 217 patients with MS, 86 patients with clinically isolated syndrome (CIS), and 212 patients with other neurological diseases (OND). In addition, we analyzed CSF cells, the first report of JCV DNA in CSF cells in a single sample, and peripheral blood cells in a subgroup of MS (n = 49), CIS (n = 14) and OND (n = 53).

RESULTS

A low copy number of JCV DNA was detected in one MS cell free CSF sample and in one MS CSF cell samples. None of these had any signs of PML or developed this disease during follow-up. In addition, two OND plasma samples were JCV DNA positive, whereas all the other samples had no detectable virus.

CONCLUSION

A low copy number of JCV DNA may occasionally be observed both in MS and other diseases and may occur as part of the normal biology of JC virus in humans. This study does not support the hypothesis that patients with MS would be at increased risk to develop PML, and consequently screening of CSF as a measurable risk for PML is not useful.