Randomized study of once-weekly interferon β-1a therapy in relapsing multiple sclerosis: three-year data from the OWIMS study

Interferon-Beta Injection in Multiple Sclerosis Patients Related to the Induction of Headache and Flu-Like Pain Symptoms: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Multiple sclerosis (MS) is a chronic neurodegenerative, inflammatory, and autoimmune disease characterised by the demyelination of the central nervous system. One of the main approaches for treating MS is the use of disease-modifying therapies (DMTs). Among the DMTs are interferons (IFNs), which are cytokines responsible for controlling the activity of the immune system while exerting immunomodulatory, antiviral, and antiproliferative activities. IFN-beta (IFN-β) is the first-choice drug used to treat relapsing-remitting MS. However, the administration of IFN-β causes numerous painful adverse effects, resulting in lower adherence to the treatment. Therefore, this study aimed to investigate the headache and flu-like pain symptoms observed after IFNβ injection in MS patients using a systematic review and meta-analysis of randomised controlled trials. A total of 2370 articles were identified through research databases. Nine articles were included (three involving IFNβ-1b and six involving IFNβ-1a). All studies included in the meta-analysis had a low risk of bias. The odds ratio of headache and flu-like pain symptoms increased in MS patients treated with IFN-β. Thus, the adverse effects of headache and flu-like pain symptoms appear to be linked to IFN-β treatment in MS. The protocol of the study was registered in the Prospective International Registry of Systematic Reviews (registration number CRD42021227593).

Intranasal delivery of interferon-β-loaded nanoparticles induces control of neuroinflammation in a preclinical model of multiple sclerosis: A promising simple, effective, non-invasive, and low-cost therapy

Multiple sclerosis (MS) is an autoimmune disease affecting the central nervous system (CNS). Interferon (IFN)-β constitutes one of the first-line therapies to treat MS, but has limited efficacy due to the injectable systemic administration, short half-life, and limited CNS access. To address these limitations, we developed IFN-β-loaded chitosan/sulfobutylether-β-cyclodextrin nanoparticles (IFN-β-NPs) for delivery of IFN-β into the CNS via the intranasal (i.n.) route. The nanoparticles (NPs) (≈200 nm, polydispersity ≈0.1, and zeta potential ≈20 mV) were prepared by mixing two aqueous solutions and associated human or murine IFN-β with high efficiency (90%). Functional in vitro assays showed that IFN-β-NPs were safe and that IFN-β was steadily released while retaining biological activity. Biodistribution analysis showed an early and high fluorescence in the brain after nasal administration of fluorescent probe-loaded NPs. Remarkably, mice developing experimental autoimmune encephalomyelitis (EAE), an experimental model of MS, exhibited a significant improvement of clinical symptoms in response to intranasal IFN-β-NPs (inIFN-β-NPs), whereas a similar dose of intranasal or systemic free IFN-β had no effect. Importantly, inIFN-β-NPs treatment was equally effective despite a reduction of 78% in the total amount of weekly administered IFN-β. Spinal cords obtained from inIFN-β-NPs-treated EAE mice showed fewer inflammatory foci and demyelination, lower expression of antigen-presenting and costimulatory proteins on CD11b⁺ cells, and lower astrocyte and microglia activation than control mice. Therefore, IFN-β treatment at tested doses was effective in promoting clinical recovery and control of neuroinflammation in EAE only when associated with NPs. Overall, inIFN-β-NPs represent a potential, effective, non-invasive, and low-cost therapy for MS.

Neutralizing antibodies in MS therapy: reviewing the Rebif experience

Treatment of relapsing-remitting multiple sclerosis (RRMS) with protein therapeutics such as interferon beta (IFNβ) frequently results in the development of binding antibodies (BAbs) to the administered agent. Neutralizing antibodies (NAbs) are a subset of BAbs characterized by their interference with IFNβ's biological target(s) and/or function(s). At the treatment group level, NAbs to IFNβ have been shown to have an impact on relapse rate and MRI disease measures. However, in individual patients, the clinical significance of NAbs remains controversial because of the lack of standardized assessment procedures, the absence of widely accepted cutoff values to distinguish NAb-positive from NAb-negative patients, and the high rate of seroconversion (to NAb-negative status) observed in clinical studies. At the recommended 44 μg tiw dose of IFNβ-1a subcutaneous (SC) (Rebif®), 12—14% of patients were persistently NAb-positive at two, three, and four years of treatment, while ~25% of anytime NAb-positive patients later became seronegative. Relapse rate and MRI measures of disease were higher in NAb-positive than NAb-negative patients; however, both demonstrated significant improvement versus placebo treatment or delayed treatment patients. Pending improved assessment methodology and better characterization of the clinical impact of NAbs, treatment decisions should continue to be based on the wide range of factors that determine clinical effectiveness. Multiple Sclerosis 2007; 13: S8—S13 http://msj.sagepub.com

Development of interferon beta-neutralising antibodies in multiple sclerosis--a systematic review and meta-analysis

PURPOSE

Interferon beta (IFN-β) is the drug of choice for treatment of relapsing forms of multiple sclerosis and is known to reduce the frequency and severity of relapses. This systematic review determines the occurrence of neutralising antibodies (NAbs) against different formulations of IFN-β: IFN-β-1a Avonex™, IFN-β-1a Rebif™ and IFN-β-1b Betaferon/Betaseron™.

METHODS

The databases used in the review included MEDLINE Ovid (from 1950 to March 2015), Embase Ovid (from 1980 to March 2015), CENTRAL on The Cochrane Library (2011, Issue 4) and ClinicalTrials.gov (from 1997 to March 2015). All studies that compared the efficacy of the different formulations of IFN-β in patients with relapsing forms of multiple sclerosis including IFN-β-1a Avonex™, IFN-β-1a Rebif™, IFN-β-1b Betaferon/Betaseron™ and IFN-β-1b Extavia™ were included.

RESULTS

Assessment of randomised controlled trials demonstrated that Avonex™ was 76% less likely than Rebif™ to lead to the formation of NAbs. Avonex™ was 88% less likely than Betaferon/Betaseron™ to lead to the formation of NAbs. Similar findings were also observed in the non-randomised controlled studies, with Avonex™ having the lowest risk. The formation of NAbs was dose dependent: Avonex™ at 30 μg was 64% less risky than Avonex™ at 60 μg.

CONCLUSIONS

Our data show that 2.0-18.9% of patients developed NAbs to Avonex™, 16.5-35.4% of patients developed NAbs to Rebif™ and 27.3-53.3% of patients developed NAbs to Betaferon/Betaseron™.

Neutralizing antibodies and fatigue as predictors of low response to interferon-beta treatment in patients with multiple sclerosis

Background

The clinical impact of neutralizing antibodies against interferon-beta (NAb) is controversial. Their presence can lead to a decrease in interferon-beta (IFNβ) efficacy. Fatigue reported in patients with multiple sclerosis (MS) may be associated with an unfavorable clinical course. We conducted a prospective multicentre study to assess the association between response to IFNβ, NAb and fatigue.

Methods

Patients with relapsing-remitting MS on IFNβ treatment were included. During the second year of treatment, the patients were analyzed for NAb status and non-response criteria to IFNβ (number of relapses ≥1 during the follow-up period, increase in the Expanded Disability Status Scale ≥0.5). The score on the Modified Fatigue Impact Scale (MFIS pathological if score ≥35) was noted for each patient.

Results

Of the 176 patients included: 22.3% were NAb positive, 54.5% presented non-response criteria to IFNβ, and 57.4% had a pathological MFIS score. Fatigue was increased in NAb + patients (p = 0.0014) and they were more likely to present non-response criteria to IFNβ (p = 0.041) than NAb- patients. Multivariate logistic regression analysis showed that the presence of NAb was related to fatigue (p = 0.0032) and denoted disease activity in these patients (p = 0.026).

Conclusions

This study demonstrates the impact of NAb on the non-clinical response to IFNβ. Fatigue assessment is an indicator of IFNβ responsiveness and a predictive biomarker of deterioration on patient’s neurological status.

Relating relapse and T2 lesion changes to disability progression in multiple sclerosis: a systematic literature review and regression analysis

Background

In the treatment of multiple sclerosis (MS), the most important therapeutic aim of disease-modifying treatments (DMTs) is to prevent or postpone long-term disability. Given the typically slow progression observed in the majority of relapsing-remitting MS (RRMS) patients, the primary endpoint for most randomized clinical trials (RCTs) is a reduction in relapse rate. It is widely assumed that reducing relapse rate will slow disability progression. Similarly, MRI studies suggest that reducing T2 lesions will be associated with slowing long-term disability in MS. The objective of this study was to evaluate the relationship between treatment effects on relapse rates and active T2 lesions to differences in disease progression (as measured by the Expanded Disability Status Scale [EDSS]) in trials evaluating patients with clinically isolated syndrome (CIS), RRMS, and secondary progressive MS (SPMS).

Methods

A systematic literature review was conducted in Medline, Embase, CENTRAL, and PsycINFO to identify randomized trials published in English from January 1, 1993-June 3, 2013 evaluating DMTs in adult MS patients using keywords for CIS, RRMS, and SPMS combined with keywords for relapse and recurrence. Eligible studies were required to report outcomes of relapse and T2 lesion changes or disease progression in CIS, RRMS, or SPMS patients receiving DMTs and have a follow-up duration of at least 22 months. Ultimately, 40 studies satisfied these criteria for inclusion. Regression analyses were conducted on RCTs to relate differences between the effect of treatments on relapse rates and on active T2 lesions to differences between the effects of treatments on disease progression (as measured by EDSS).

Results

Regression analysis determined there is a substantive clinically and statistically significant association between concurrent treatment effects in relapse rate and EDSS; p < 0.01. Lower treatment effects were associated with higher relative rates of disease progression. Significant associations between T2 lesion measures and EDSS measures also were found (p < 0.05), with some suggestion that the strength of the association may differ for older versus newer DMTs.

Conclusions

Treatment differences in relapse reduction and T2 lesions are positively related to differences in disease progression over the first two years of treatment.

[Interferon-β1b in multiple sclerosis therapy: more than 20 years clinical experience]

The introduction of interferon-β1b in 1993 in the USA and 2 years later in Europe made it possible for the first time to alter the course of the disease in patients with relapsing-remitting multiple sclerosis (MS). Subsequently, interferon-β1b was approved for the treatment of patients with active secondary progressive MS (1999) and early relapsing-remitting MS following a first demyelinating event (clinically isolated syndrome, CIS) (2006). Here we provide an overview of the clinical experience gathered during more than 20 years of interferon-β use focusing on long-term efficacy and safety and the impact of early initiation of treatment. Furthermore, the following aspects will be discussed: putative mechanisms of action of interferon-β, indications for a disease-modifying therapy, clinical relevance of neutralizing antibodies, importance of adherence in MS therapy, high versus low frequency therapy, combination therapies with interferon-β and safety of interferon-β in children and adolescents with MS and during pregnancy.

Effect of treatment regimen on the immunogenicity of human interferon Beta in immune tolerant mice

PURPOSE

Interferon beta is commonly used as therapeutic in the first line of therapy for multiple sclerosis. However, depending on the product, it induces an antibody response in up to 60% of patients. This study evaluated the impact of therapy related factors like dose, route of administration and administration frequency on the immunogenicity of one of the originator interferon beta drugs (Betaferon®) in an immune tolerant transgenic mouse model.

METHODS

Immune tolerant transgenic mice received injections with Betaferon® via different routes, doses and injection frequencies. Anti-drug antibody (ADA) production was measured by ELISA to assess immunogenicity.

RESULTS

A single injection of Betaferon® was found to be sufficient for the induction of ADAs. The antibody titer was enhanced with increasing dose and treatment frequency. Among the tested administration routes, the intravenous route was the most immunogenic one, which is in contradiction with one of the dogma in immunogenicity research according to which subcutaneous administration is the most immunogenic route. Intramuscular, intraperitoneal and subcutaneous injections resulted in comparable immunogenicity.

CONCLUSION

This study shows that treatment related factors affect significantly immunogenicity of Betaseron® and therefore substantiate the need for further studies on these factors in patients.

Cutaneous adverse events associated with disease-modifying treatment in multiple sclerosis: a systematic review

Glatiramer acetate and interferon-beta are approved first-line disease-modifying treatments (DMTs) for multiple sclerosis (MS). DMTs can be associated with cutaneous adverse events, which may influence treatment adherence and patient quality of life. In this systematic review, we aimed to provide an overview of the clinical spectrum and the incidence of skin reactions associated with DMTs. A systematic literature search was performed up to May 2011 in Medline, Embase, and Cochrane databases without applying restrictions in study design, language, or publishing date. Eligible for inclusion were articles describing any skin reaction related to DMTs in MS patients. Selection of articles and data extraction were performed by two authors independently. One hundred and six articles were included, of which 41 (39%) were randomized controlled trials or cohort studies reporting incidences of mainly local injection-site reactions. A large number of patients had experienced some form of localized injection-site reaction: up to 90% for those using subcutaneous formulations and up to 33% for those using an intramuscular formulation. Sixty-five case-reports involving 106 MS patients described a wide spectrum of cutaneous adverse events, the most frequently reported being lipoatrophy, cutaneous necrosis and ulcers, and various immune-mediated inflammatory skin diseases. DMTs for MS are frequently associated with local injection-site reactions and a wide spectrum of generalized cutaneous adverse events, in particular, the subcutaneous formulations. Although some of the skin reactions may be severe and persistent, most of them are mild and do not require cessation of DMT.

Classical immunomodulatory therapy in multiple sclerosis: how it acts, how it works

Interferon beta (IFNβ) and glatiramer acetate (GA) were the first immunomodulators approved to the treatment of relapsing-remitting multiple sclerosis (MS) and clinically isolated syndromes. Despite the enlargement of the therapeutic armamentarium, IFNβ and GA remain the most widely drugs and the therapeutic mainstay of MS.

OBJECTIVE

To review the mechanisms of action of IFNβ and GA and main clinical results in MS.

RESULTS

IFNβ modulates T and B-cell activity and has effects on the blood-brain barrier. The well proved mechanism of GA is an immune deviation by inducing expression of anti-inflammatory cytokines. Some authors favor the neuroprotective role of both molecules. Clinical trials showed a 30% reduction on the annualized relapse rate and of T2 lesions on magnetic resonance.

CONCLUSION

Although the precise mechanisms how IFNβ and GA achieve their therapeutics effects remain unclear, these drugs have recognized beneficial effects and possess good safety and tolerability profiles. The large clinical experience in treating MS patients with these drugs along almost two decades deserves to be emphasized, at a time where the appearance of drugs with more selective mechanisms of action, but potentially less safer, pave the way to a better selection of the most appropriate individualized treatment.

Systematic review of disease-modifying therapies to assess unmet needs in multiple sclerosis: tolerability and adherence

Reviews of therapeutic drugs usually focus on the highly selected and closely monitored patient populations from randomized controlled trials. The objective of this study was to review systematically the tolerability and adherence of multiple sclerosis disease-modifying therapies, using data from both randomized controlled trials and observational settings. Relevant literature was identified using predefined search terms, and adverse event and study discontinuation data were extracted and categorized according to study type (randomized controlled trial or observational) and study duration. A total of 151 papers were selected for analysis; 33% were classified as randomized controlled trials and 62% as observational studies. Most of the papers concerned interferon preparations and glatiramer acetate; the limited available information on mitoxantrone and natalizumab precluded extensive examination of these. The most common adverse events were flu-like symptoms (interferon therapies only) and injection-site reactions. Mean discontinuation rates ranged from 16% to 27%. There were no marked differences in tolerability or adherence data from randomized controlled trials and observational studies, but the incidence of adverse events remained high in lengthy studies and discontinuations accumulated with time. The present systematic review of randomized clinical trial and observational data highlights the tolerability and adherence issues associated with commonly used first-line multiple sclerosis treatments.

Neutralizing antibodies against interferon-Beta

The development of neutralizing antibodies (NAbs) is a major problem in multiple sclerosis (MS) patients treated with interferon-beta (IFN-ß). Whereas binding antibodies (BAbs) can be demonstrated in the vast majority of patients, only a smaller proportion of patients develop NAbs. The principle in NAb in vitro assays is the utilization of cultured cell lines that are responsive to IFN-ß. The cytopathic effect (CPE) assay measures the capacity of NAbs to neutralize IFN- ß's protective effect on cells challenged with virus and the MxA induction assay measures the ability of NAbs to reduce the IFN-ß-induced expression of MxA, either at the mRNA or the protein level. A titer of >20 neutralizing units/ml traditionally defines NAb posi-tivity. NAbs in high titers completely abrogate the in vivo response to IFN-ß, whereas the effect of low and intermediate titers is unpredictable. As clinically important NAbs appear only after 9-18 months IFN- ß0 therapy, short-term studies of two years or less are unsuitable for evaluation of clinical NAb effects. All long-term trials of three years or more concordantly show evidence of a detrimental effect of NAbs on relapses, disease activity on MRI, or on disease progression. Persistent high titers of NAbs indicate an abrogation of the biological response and, hence, absence of therapeutic efficacy, and this observation should lead to a change of therapy. As low and medium titers are ambiguous treatment decisions in patients with low NAb titres should be guided by determination of in vivo mRNA MxA induction and clinical disease activity.

Gender effects on intramuscular interferon beta-1a in relapsing–remitting multiple sclerosis: analysis of 1406 patients

Background: We aimed to evaluate effects of gender on efficacy and safety of intramuscular (IM) interferon beta (IFNβ)-1a in patients with relapsing–remitting MS (RRMS) or clinically isolated syndromes (CIS) characteristic of early MS.

Methods: Pooled data from 1406 (1027 women; 379 men) patients enrolled in five clinical studies of IM IFNβ-1a were analyzed. One analysis examined data for all patients treated with IM IFNβ-1a from all studies. Separate analyses were conducted of pooled IM IFNβ-1a-treated groups from all studies and pooled IFNβ-1a-treated and placebo-treated patients from the placebo-controlled studies. Outcome measures included time to first relapse, annualized relapse rate, time to disability progression, number of gadolinium-enhanced lesions, adverse events, laboratory evaluations, and neutralizing antibodies.

Results: All efficacy assessments indicated similar treatment effects of IM IFNβ-1a in men and women with no significant treatment-by-gender interactions. Women reported more headaches, urinary tract infections, and depression in the analysis; however, these were also common in women who received placebo. Men reported more frequent flu-like symptoms in the placebo-controlled studies only. There were no other differences in the safety profile of IM IFNβ-1a between men and women.

Conclusions: We conclude that no significant gender-related differences were found in the efficacy and safety of IM IFNβ-1a in patients with RRMS or CIS.

Assessing changes in relapse rates in multiple sclerosis

Multiple Sclerosis (MS) annualized relapse rates (ARRs) in trials may be declining due to changes in diagnostic criteria, MS etiology, study criteria, and selection biases. This review examines if there is a trend in the ARR for relapsing-remitting MS patients (RRMS) over time and if so, why. A comprehensive literature search was performed using PubMed, Web of Science(®), and the Cochrane Library using electronic searches, screen scraping for abstracts, and hand searching of references for randomized trials conducted between 1960 and 2008. Out of 72 randomized trials, 56 (77.8%) defined relapse. This study uses 32 placebo relapsing-remitting studies out of the 37 (66.1%) with RRMS. The mean ARR for the treatment arms was 0.68 and the one for the placebo groups was 1.002. The year of publication was negatively associated with the ARR (p = 0.0001). The annual reduction amounts to 0.36 relapses over a 10-year period. Age and duration of symptoms were negatively associated with the ARR. Year of publication was significantly negatively associated with ARR after controlling for covariates. ARRs have fallen with relapse definition, entrance criteria remain important, but time exceeds all these variables and reflects two likely sources, selection of patients for trials by clinicians and rescue of patients truncating the number of multiple relapses. The impact of truncating the number of relapses on the falling rates is important, not only on the ARRs, but also on the impact of informative censoring in drop-outs.

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.

High-dose, high-frequency recombinant interferon beta-1a in the treatment of multiple sclerosis

BACKGROUND

There is at present no cure for multiple sclerosis (MS), and existing therapies are designed primarily to prevent lesion formation, decrease the rate and severity of relapses and delay the resulting disability by reducing levels of inflammation.

OBJECTIVE

The aim of this review was to assess the treatment of relapsing MS with particular focus on subcutaneous (s.c.) interferon (IFN) beta-1a.

METHOD

The literature on IFN beta-1a therapy of MS was reviewed based on a PubMed search (English-language publications from 1990) including its pharmacodynamics and pharmacokinetics, clinical efficacy in relapsing MS as shown in placebo-controlled studies and in comparative trials, efficacy in secondary progressive MS, safety and tolerability, and the impact of neutralizing antibodies.

CONCLUSION

The literature suggests that high-dose, high-frequency s.c. IFN beta-1a offers an effective option for treating patients with relapsing MS, with proven long-term safety and tolerability, and has a favourable benefit-to-risk ratio compared with other forms of IFN beta.

Dose response to interferon therapy in multiple sclerosis: an evaluation of the evidence

BACKGROUND

Interferon beta (IFNbeta) is a disease-modifying therapy for multiple sclerosis (MS). Although clinical benefits have been demonstrated in several large, randomized, double-blind studies, the optimal dosing of IFNbeta is controversial.

METHODS

A search was conducted using the key words IFNbeta, multiple sclerosis, Avonex, Rebif, Betaseron/Betaferon, efficacy, MRI, and dose-response relationship in MEDLINE, EMBASE, and other databases to locate relevant pivotal clinical trials, other prospective studies, and systematic reviews evaluating the efficacy and tolerability of IFNbeta published between 1985 and 2007. This review summarizes the findings of these studies with regard to defining the value of high-dose, high-frequency (HDHF) IFNbeta regimens.

REVIEW SUMMARY

All IFNbeta formulations and dosages have demonstrated efficacy in well-designed phase 3 trials. Two head-to-head trials suggesting that HDHF regimens result in increased efficacy contained shortfalls in study design that precluded definitive conclusions.

CONCLUSION

Defining the optimal dose and frequency strategy for IFNbeta in patients with MS is complicated by the differences in dosage, route, and frequency of administration among the various agents. Results of well-controlled pivotal trials do not suggest that HDHF IFNbeta regimens provide better long-term benefits for patients with MS than low-dose or low-frequency regimens. In addition, HDHF therapies may increase the incidence of side-effects and neutralizing antibodies that reduce efficacy over time. Although the two head-to-head comparisons of different IFNbeta therapies found HDHF regimens to be more efficacious than lower-dose/lower-frequency regimens, the design limitations of these studies must be considered when weighing the potential value of the findings for recommending treatment strategies.

Basic and escalating immunomodulatory treatments in multiple sclerosis: current therapeutic recommendations

This review updates and extends earlier Consensus Reports related to current basic and escalating immunomodulatory treatments in multiple sclerosis (MS). The recent literature has been extracted for new evidence from randomized controlled trials, open treatment studies and reported expert opinion, both in original articles and reviews, and evaluates indications and safety issues based on published data. After data extraction from published full length publications and critically weighing the evidence and potential impact of the data, the review has been drafted and circulated within the National MS Societies and the European MS Platform to reach consensus within a very large group of European experts, combining evidence-based criteria and expert opinion where evidence is still incomplete. The review also outlines a few areas of controversy and delineates the need for future research.

Pharmacokinetics and pharmacodynamics of the interferon-betas, glatiramer acetate, and mitoxantrone in multiple sclerosis

Five disease-modifying agents are currently approved for long-term treatment of multiple sclerosis (MS), namely three interferon-beta preparations, glatiramer acetate, and mitoxantrone(1). Pharmacokinetics describes the fate of drugs in the human body by studying their absorption, distribution, metabolism and excretion. Pharmacodynamics is dedicated to the mechanisms of action of drugs. The understanding of the pharmacokinetics and pharmacodynamics of the approved disease-modifying agents against MS is of importance as it might contribute to the development of future derivatives with a potentially higher efficacy and a more favourable safety profile. This article reviews data thus far present both on the pharmacokinetics as well as on the putative mechanisms of action of the interferon-betas, glatiramer acetate, and mitoxantrone in the immunopathogenesis of MS.

The safety and efficacy of IFN-beta products for the treatment of multiple sclerosis

Multiple sclerosis, a chronic demyelinating disease of the CNS, is now a treatable disease. Phase III clinical trials of three recombinant IFN-beta products conducted in relapsing-remitting multiple sclerosis have shown, albeit modest, significant effects on relapses and short-term progression of disability, and a more substantial effect on MRI parameters. However, these effects do not correlate well with clinical disease activity or long-term disability. Overall, IFN-beta is safe and generally well tolerated, and reported adverse events were comparable between preparations. Systemic side effects can be effectively managed by dose escalation, use of an auto-injector and careful clinical monitoring.

Anti-glycan antibodies as biomarkers for diagnosis and prognosis

Glycans (sugars or carbohydrates) are predominant surface components of cells such as erythrocytes, immune cells and microorganisms. As such, they give rise to high levels of anti-glycan antibodies of all classes. Antibodies to certain defined mono, di and oligosaccharides that are common in bacterial, fungal and parasite cells exist in human sera and can be profiled using glycan arrays. The use of glycan arrays for systematic screening of blood samples from multiple sclerosis (MS) and Crohn's disease (CD) patients in versus to blood samples from control groups, have lead to the discovery of a few anti glycan antibodies biomarkers enabling diagnosis and prognosis in MS and CD patients. Anti-Glc(alpha1,4)Glc(alpha) IgM antibodies were found to be specific for MS patients, enabling differentiation between MS patients and patients with other neurological diseases, with 54% sensitivity and 85% specificity. Anti-Glc(alpha1,4)Glc(alpha) IgM were found to be predictive for the conversion of patients in first acute neurological event to clinically defined MS. Anti-laminaribioside (ALCA), anti-mannobioside (AMCA) and anti-chitobioside (ACCA) antibodies were found to be specific for CD. The combined use of these antibodies enables improved diagnosis of CD versus ulcerative colitis and other gastrointestinal diseases, as well as stratification of CD patients with a more complicated disease and high risk for surgery. Anti-glycan antibodies profiling (AGAP) is a new and promising approach for development of biomarkers for diagnosis and prognosis.

Immunmodulatorische Stufentherapie der Multiplen Sklerose

The updated recommendations presented here reflect new developments in the diagnostic work-up and immunotherapy of multiple sclerosis (MS) as well as optimization of medical care for MS patients. Monoclonal antibodies provide considerable improvement of treatment, but their use in basic therapy is restricted by their side effect profile. Thus, for the time being, natalizumab is only approved for monotherapy after basic treatment has failed or for rapidly progressive relapsing-remitting MS. In contrast, long-term data on recombinant beta-interferons and glatiramer acetate (Copaxone) show that even after several years no unexpected side effects occur and that a prolonged therapeutic effect can be assumed which correlates with the dose or frequency of treatment. Recently IFN-beta1b (Betaferon) was approved for prophylactic treatment after the first attack (clinically isolated syndrome, CIS). During treatment with beta-interferons, neutralizing antibodies can emerge with possible loss of effectivity. In contrast, antibodies play no role in treatment with glatiramer acetate. During or after therapy with mitoxantrone, serious side effects (cardiomyopathy, acute myeloid leukemia) appeared in 0.2-0.4% of cases. Plasmapheresis is limited to individual curative attempts in escalating therapy of a severe attack. According to the revised McDonald criteria, the diagnosis of MS can be made as early as the occurrence of the first attack (CIS). Recommendations for optimized care of MS patients are also new, thus implementing a resolution of the European Parliament.

Neutralising antibodies to IFN-β in patients with multiple sclerosis

The development of neutralising antibodies (NABs), or neutralising activity in the absence of NABs, is a potential complication of therapy with interferon (IFN)-beta for patients with multiple sclerosis, limiting therapeutic efficacy. Discontinuation of IFN-beta therapy in patients found to have sustained titres of NABs > 1:100 over an interval of 3 - 6 months has been recently proposed as a Level A recommendation. The extent to which NABs are causative, rather than an epiphenomenon, in determining drug failure has been a matter of numerous investigations and is still controversial. Thus, further studies are warranted for determining the role that NABs may play in reducing the response to the drug. In particular, the effects of NABs in reducing the efficacy of IFN-beta therapy beyond clinical relapse rate and lesion load on conventional imaging are not as yet fully understood.