Alemtuzumab: a new therapy for active relapsing-remitting multiple sclerosis.

Alemtuzumab is a humanized monoclonal antibody directed against CD52 to deplete circulating T and B lymphocytes; lymphocyte depletion is followed by a distinctive pattern of T- and B-cell repopulation, changing the balance of the immune system. This review reports the efficacy and safety findings of the phase 2 CAMMS223 trial and the phase 3 CARE-MS I and II trials investigating alemtuzumab for the treatment of active relapsing-remitting MS. Alemtuzumab, administered intravenously, was shown to improve relapse rate versus subcutaneous interferon beta-1a in patients who were treatment-naive (CAMMS223 and CARE-MS I) or had relapsed on prior therapy (CARE-MS II), and to reduce sustained accumulation of disability (CAMMS223 and CARE-MS II). Important adverse events were infusion-associated reactions, serious infections and autoimmune events. A safety monitoring program allowed for early detection and management of autoimmune events. Recommendations for the monitoring of adverse events are made. Alemtuzumab's mechanism of action, pharmacodynamics and opportunities for future research are discussed.

Liposome-encapsulated peptides protect against experimental allergic encephalitis.

Multiple sclerosis (MS) is a severe inflammatory and neurodegenerative disease with an autoimmune background. Despite the variety of therapeutics available against MS, the development of novel approaches to its treatment is of high importance in modern pharmaceutics. In this study, experimental autoimmune encephalomyelitis (EAE) in Dark Agouti rats has been treated with immunodominant peptides of the myelin basic protein (MBP) encapsulated in mannosylated small unilamellar vesicles. The results show that liposome-encapsulated MBP(46-62) is the most effective in reducing maximal disease score during the first attack, while MBP(124-139) and MBP(147-170) can completely prevent the development of the exacerbation stage. Both mannosylation of liposomes and encapsulation of peptides are critical for the therapeutic effect, since neither naked peptides nor nonmannosylated liposomes, loaded or empty, have proved effective. The liposome-mediated synergistic effect of the mixture of 3 MBP peptides significantly suppresses the progression of protracted EAE, with the median cumulative disease score being reduced from 22 to 14 points, compared to the placebo group; prevents the production of circulating autoantibodies; down-regulates the synthesis of Th1 cytokines; and induces the production of brain-derived neurotrophic factor in the central nervous system. Thus, the proposed formulation ameliorates EAE, providing for a less severe first attack and rapid recovery from exacerbation, and offers a promising therapeutic modality in MS treatment.

Combinatorial antibody library from multiple sclerosis patients reveals antibodies that cross-react with myelin basic protein and EBV antigen.

Multiple sclerosis (MS) is a widespread neurodegenerative autoimmune disease with unknown etiology. It is increasingly evident that, together with pathogenic T cells, autoreactive B cells are among the major players in MS development. The analysis of myelin neuroantigen-specific antibody repertoires and their possible cross-reactivity against environmental antigens, including viral proteins, could shed light on the mechanism of MS induction and progression. A phage display library of single-chain variable fragments (scFvs) was constructed from blood lymphocytes of patients with MS as a potential source of representative MS autoantibodies. Structural alignment of 13 clones selected toward myelin basic protein (MBP), one of the major myelin antigens, showed high homology within variable regions with cerebrospinal fluid MS-associated antibodies as well as with antibodies toward Epstein-Barr latent membrane protein 1 (LMP1). Three scFv clones showed pronounced specificity to MBP fragments 65-92 and 130-156, similar to the serum MS antibodies. One of these clones, designated E2, in both scFv and full-size human antibody constructs, was shown to react with both MBP and LMP1 proteins in vitro, suggesting natural cross-reactivity. Thus, antibodies induced against LMP1 during Epstein-Barr virus infection might act as inflammatory trigger by reacting with MBP, suggesting molecular mimicry in the mechanism of MS pathogenesis.

Alemtuzumab outcomes by age: Post hoc analysis from the randomized CARE-MS studies over 8 years.

BACKGROUND: Alemtuzumab significantly improved clinical and MRI outcomes vs. subcutaneous interferon beta-1a (SC IFNB-1a) in the CARE-MS trials (NCT00530348, NCT00548405), with sustained efficacy in 2 consecutive extensions (NCT00930553, NCT02255656 [TOPAZ]). METHODS: Post hoc analysis of 8-year alemtuzumab efficacy and safety in pooled CARE-MS patients (N=811) stratified by baseline age (≥18 to ≤25, >25 to ≤35, >35 to ≤45, >45 to ≤55 years). RESULTS: Compared with SC IFNB-1a over 2 years across age cohorts, alemtuzumab lowered annualized relapse rates (ARR; 0.22-0.24 vs. 0.38-0.51), improved or stabilized disability (freedom from 6-month confirmed disability worsening [CDW]: 85%-92% vs. 62%-88%; achievement of 6-month confirmed disability improvement [CDI]: 20%-31% vs. 13%-25%), increased proportions free of MRI disease activity (70%-86% vs. 42%-63% per year), and slowed brain volume loss (BVL; -0.45% to -0.87% vs. -0.50% to -1.39%). Through Year 2, the treatment effect with alemtuzumab did not significantly differ among age groups for ARR (p-interaction=0.6325), 6-month CDW-free (p-interaction=0.4959), 6-month CDI (p-interaction=0.9268), MRI disease activity-free (p-interaction=0.6512), and BVL (p-interaction=0.4970). Alemtuzumab remained effective on outcomes through Year 8 across age groups. Age-related increases in malignancies (≤45 years: 0.9%-2.2% vs. >45 years: 8.1%) and deaths (0%-1.7% vs. 7.0%) were observed. Serious infections also increased from the youngest (5.1%) to oldest (12.8%) age cohorts. CONCLUSIONS: Alemtuzumab had greater efficacy than SC IFNB-1a over 2 years across comparable age groups, with no significant differences between alemtuzumab-treated age groups. Efficacy on relapse, disability, and MRI outcomes continued through Year 8 across age groups. Age-related increases in serious infections, malignancies, and deaths were observed.

Cladribine tablets' potential role as a key example of selective immune reconstitution therapy in multiple sclerosis.

Multiple sclerosis (MS) is one of the most important, disabling, and prevalent neurological disorders of young adults. It is a chronic inflammatory and neurodegenerative disease when autoreactive B and T cells have downstream effects that result in demyelination and neuronal loss. Anti-inflammatory disease-modifying therapies do have proven efficacy in delaying disease and disability progression in MS. While the progress in MS treatments has already improved the prognosis and quality of patients' lives overall, there are some clear shortcomings and unmet needs in the current MS treatment landscape. The most promising means of MS treatment is selective immune reconstitution therapy (SIRT). This therapy is given in short-duration courses of immunosuppression, producing durable effects on the immune system and preventing nervous tissue loss. This review discusses the mechanisms of action and the data of clinical trials of cladribine tablets as an example of SIRT in MS. The clinical benefits of cladribine tablets in these studies include decreased relapse rate and disability progression with large reductions in lesion activity, and protection against brain volume loss. Whether all of these neurological findings are direct results of lymphocyte depletion, or if there are downstream effects on other, unknown, neurodegenerative processes are yet to be determined, but these clearly point to an interesting area of research.

Comparative pharmacogenetics of multiple sclerosis: IFN-ß versus glatiramer acetate.

Various diseases require the selection of preferable treatment out of available alternatives. Multiple sclerosis (MS), an autoimmune inflammatory/neurodegenerative disease of the CNS, requires long-term medication with either specific disease-modifying therapy (DMT) - IFN-ß or glatiramer acetate (GA) - which remain the only first-line DMTs in all countries. A significant share of MS patients are resistant to treatment with one or the other DMT; therefore, the earliest choice of preferable DMT is of particular importance. A number of conventional pharmacogenetic studies performed up to the present day have identified the treatment-sensitive genetic biomarkers that might be specific for the particular drug; however, the suitable biomarkers for selection of one or another first-line DMT are remained to be found. Comparative pharmacogenetic analysis may allow the identification of the discriminative genetic biomarkers, which may be more informative for an a priori DMT choice than those found in conventional pharmacogenetic studies. The search for discriminative markers of preferable first-line DMT, which differ in carriage between IFN-ß responders and GA responders as well as between IFN-ß nonresponders and GA nonresponders, has been performed in 253 IFN-ß-treated MS patients and 285 GA-treated MS patients. A bioinformatics algorithm for identification of composite biomarkers (allelic sets) was applied on a unified set of immune-response genes, which are relevant for IFN-ß and/or GA modes of action, and identical clinical criteria of treatment response. We found the range of discriminative markers, which include polymorphic variants of CCR5, IFNAR1, TGFB1, DRB1 or CTLA4 genes, in different combinations. Every allelic set includes the CCR5 genetic variant, which probably suggests its crucial role in the modulation of the DMT response. Special attention should be given to the (CCR5*d+ IFNAR1*G) discriminative combination, which clearly points towards IFN-ß treatment choice for carriers of this combination. As a whole the comparative approach provides an option for the identification of prognostic composite biomarkers for a preferable medication among available alternatives.

Heavy-light chain interrelations of MS-associated immunoglobulins probed by deep sequencing and rational variation.

The mechanisms triggering most of autoimmune diseases are still obscure. Autoreactive B cells play a crucial role in the development of such pathologies and, in particular, production of autoantibodies of different specificities. The combination of deep-sequencing technology with functional studies of antibodies selected from highly representative immunoglobulin combinatorial libraries may provide unique information on specific features in the repertoires of autoreactive B cells. Here, we have analyzed cross-combinations of the variable regions of human immunoglobulins against the myelin basic protein (MBP) previously selected from a multiple sclerosis (MS)-related scFv phage-display library. On the other hand, we have performed deep sequencing of the sublibraries of scFvs against MBP, Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1), and myelin oligodendrocyte glycoprotein (MOG). Bioinformatics analysis of sequencing data and surface plasmon resonance (SPR) studies have shown that it is the variable fragments of antibody heavy chains that mainly determine both the affinity of antibodies to the parent autoantigen and their cross-reactivity. It is suggested that LMP1-cross-reactive anti-myelin autoantibodies contain heavy chains encoded by certain germline gene segments, which may be a hallmark of the EBV-specific B cell subpopulation involved in MS triggering.

Allelic combinations of immune-response genes as possible composite markers of IFN-ß efficacy in multiple sclerosis patients.

BACKGROUND: IFN-ß is widely used as the first-line disease-modifying treatment for multiple sclerosis. However, 30-50% of multiple sclerosis patients do not respond to this therapy. Identification of genetic variants and their combinations that predict responsiveness to IFN-ß could be useful for treatment prognosis. MATERIALS & METHODS: The combinations of alleles of nine polymorphic loci in immune-response genes were analyzed in 253 Russian multiple sclerosis patients as possible determinants of clinically optimal IFN-ß treatment response using APSampler software. RESULTS: Carriage of TGFB1*-509C and CCR5*d was associated with favorable IFN-ß response by itself. CCR5*d, IFNAR1*16725G, IFNG*874T and IFNB1*153T/T were the components of the combinations, associated with clinically optimal response to IFN-ß. Carriage of composite markers (CCR5*d + IFNAR1*G + IFNB1*T/T) or (CCR5*d + IFNAR1*G + IFNG*T) is beneficial for IFN-ß treatment efficacy. DISCUSSION: The data obtained provides evidence of the cumulative effect of immune-response genes on IFN-ß treatment efficacy. This joint contribution may reflect the additive effect of independent allelic variants and epistatic interactions between some of them.

Allelic combinations of immune-response genes associated with glatiramer acetate treatment response in Russian multiple sclerosis patients.

BACKGROUND: Glatiramer acetate (GA) is widely used as a first-line disease-modifying treatment for multiple sclerosis (MS). However, a significant proportion of MS patient appears to experience modest benefit from GA-treatment. Genetic variants affecting the clinical response to GA are believed to be relevant as biomarkers of GA-treatment efficiency. PATIENTS & METHODS: Nine polymorphisms in candidate genes were analyzed as possible determinants of GA response in 285 Russian MS patients. Special attention was given to identification of response-associated allelic combinations by means of the APSampler algorithm. RESULTS: No significant associations were found for individual polymorphisms. Alleles DRB1*15, TGFB1*T, CCR5*d and IFNAR1*G were the components of the combinations, of which carriage was significantly higher in nonresponders than in responders. Carriers of the most significant combinations: DRB1*15 + TGFB1*T + CCR5*d + IFNAR1*G and DRB1*15 + TGFB1*T + CCR5*d (permutation p-values: 0.0056 and 0.013, respectively) had a 14 to 15-times increased risk of ineffective response to GA therapy. DISCUSSION: The results suggest that the influence of immune-response genes on GA-induced response has a polygenic nature. The data are interpreted as evidence of additive and epistatic influences of the genes on GA efficiency for MS treatment.

Clinical effects and tolerability of high-dose, high-frequency recombinant interferon beta-1a in patients with multiple sclerosis: maximizing therapy through long-term adherence.

IMPORTANCE OF THE FIELD: High-dose, high-frequency IFN beta-1a in multiple sclerosis (MS) can prevent lesion formation, decrease the frequency/severity of relapses and delay progression of disability, with a proven safety profile. Rates of non-adherence are high. There are drugs under investigation that may have greater efficacy and different safety profiles from existing therapies. AREAS COVERED IN THIS REVIEW: Evidence supporting the efficacy of IFN beta-1a, factors contributing to non-adherence, and strategies to combat non-adherence. It is hoped that these strategies, coupled with future advances in pharmacogenetics, might lead to better outcomes. The PubMed database was searched using the terms "multiple sclerosis" and "interferon beta-1a", for papers published between 1998 and 2010. Relevant manuscripts and pivotal papers from clinical trials were cited. Searches of abstracts from congresses were also performed to obtain recent findings. WHAT THE READER WILL GAIN: An overview of early pivotal trials, comparative studies with other treatments, and recent studies assessing the development of this therapy. TAKE HOME MESSAGE: Long-term treatment with IFN beta-1a has benefits in MS and a good safety profile. Although adherence outside of clinical trials can be poor, injection devices, better tolerated drug formulations and education regarding treatment expectations are some of the strategies employed to help patients to adhere to treatment in the hope of improving outcomes.