Recommendations for clinical use of data on neutralising antibodies to interferon-beta therapy in multiple sclerosis

Global DNA Methylation and Hydroxymethylation Levels in PBMCs Are Altered in RRMS Patients Treated with IFN-β and GA-A Preliminary Study

Multiple sclerosis (MS) is a chronic disease affecting the central nervous system (CNS) due to an autoimmune attack on axonal myelin sheaths. Epigenetics is an open research topic on MS, which has been investigated in search of biomarkers and treatment targets for this heterogeneous disease. In this study, we quantified global levels of epigenetic marks using an ELISA-like approach in Peripheral Blood Mononuclear Cells (PBMCs) from 52 patients with MS, treated with Interferon beta (IFN-β) and Glatiramer Acetate (GA) or untreated, and 30 healthy controls. We performed media comparisons and correlation analyses of these epigenetic markers with clinical variables in subgroups of patients and controls. We observed that DNA methylation (5-mC) decreased in treated patients compared with untreated and healthy controls. Moreover, 5-mC and hydroxymethylation (5-hmC) correlated with clinical variables. In contrast, histone H3 and H4 acetylation did not correlate with the disease variables considered. Globally quantified epigenetic DNA marks 5-mC and 5-hmC correlate with disease and were altered with treatment. However, to date, no biomarker has been identified that can predict the potential response to therapy before treatment initiation.

A unified classification approach rating clinical utility of protein biomarkers across neurologic diseases

A major evolution from purely clinical diagnoses to biomarker supported clinical diagnosing has been occurring over the past years in neurology. High-throughput methods, such as next-generation sequencing and mass spectrometry-based proteomics along with improved neuroimaging methods, are accelerating this development. This calls for a consensus framework that is broadly applicable and provides a spot-on overview of the clinical validity of novel biomarkers. We propose a harmonized terminology and a uniform concept that stratifies biomarkers according to clinical context of use and evidence levels, adapted from existing frameworks in oncology with a strong focus on (epi)genetic markers and treatment context. We demonstrate that this framework allows for a consistent assessment of clinical validity across disease entities and that sufficient evidence for many clinical applications of protein biomarkers is lacking. Our framework may help to identify promising biomarker candidates and classify their applications by clinical context, aiming for routine clinical use of (protein) biomarkers in neurology.

Antidrug Antibodies Against Biological Treatments for Multiple Sclerosis

The development of antidrug antibodies (ADAs) is a major problem in several recombinant protein therapies used in the treatment of multiple sclerosis (MS). The etiology of ADAs is multifaceted. The predisposition for a breakdown of immune tolerance is probably genetically determined, and many factors may contribute to the immunogenicity, including structural properties, formation of aggregates, and presence of contaminants and impurities from the industrial manufacturing process. ADAs may have a neutralizing capacity and can reduce or abrogate the bioactivity and therapeutic efficacy of the drug and cause safety issues. Interferon (IFN)-β was the first drug approved for the treatment of MS, and-although it is generally recognized that neutralizing antibodies (NAbs) appear and potentially have a negative effect on therapeutic efficacy-the use of routine measurements of NAbs and the interpretation of the presence of NAbs has been debated at length. NAbs appear after 9-18 months of therapy in up to 40% of patients treated with IFNβ, and the frequency and titers of NAbs depend on the IFNβ preparation. Although all pivotal clinical trials of approved IFNβ products in MS exhibited a detrimental effect of NAbs after prolonged therapy, some subsequent studies did not observe clinical effects from NAbs, which led to the claim that NAbs did not matter. However, it is now largely agreed that persistently high titers of NAbs indicate an abrogation of the biological response and, hence, an absence of therapeutic efficacy, and this observation should lead to a change of therapy. Low and medium titers are ambiguous, and treatment decisions should be guided by determination of in vivo messenger RNA myxovirus resistance protein A induction after IFNβ administration and clinical disease activity. During treatment with glatiramer acetate, ADAs occur frequently but do not appear to adversely affect treatment efficacy or result in adverse events. ADAs occur in approximately 5% of patients treated with natalizumab within 6 months of therapy, and persistent NAbs are associated with a lack of efficacy and acute infusion-related reactions and should instigate a change of therapy. When using the anti-CD20 monoclonal antibodies ocrelizumab and ofatumumab in the treatment of MS, it is not necessary to test for NAbs as these occur very infrequently. Alemtuzumab is immunogenic, but routine measurements of ADAs are not recommended as the antibodies in the pivotal 2-year trials at the population level did not influence lymphocyte depletion or repopulation, efficacy, or safety. However, in some individuals, NAbs led to poor lymphocyte depletion.

Current and Future Biomarkers in Multiple Sclerosis

Multiple sclerosis (MS) is a debilitating autoimmune disorder. Currently, there is a lack of effective treatment for the progressive form of MS, partly due to insensitive readout for neurodegeneration. The recent development of sensitive assays for neurofilament light chain (NfL) has made it a potential new biomarker in predicting MS disease activity and progression, providing an additional readout in clinical trials. However, NfL is elevated in other neurodegenerative disorders besides MS, and, furthermore, it is also confounded by age, body mass index (BMI), and blood volume. Additionally, there is considerable overlap in the range of serum NfL (sNfL) levels compared to healthy controls. These confounders demonstrate the limitations of using solely NfL as a marker to monitor disease activity in MS patients. Other blood and cerebrospinal fluid (CSF) biomarkers of axonal damage, neuronal damage, glial dysfunction, demyelination, and inflammation have been studied as actionable biomarkers for MS and have provided insight into the pathology underlying the disease process of MS. However, these other biomarkers may be plagued with similar issues as NfL. Using biomarkers of a bioinformatic approach that includes cellular studies, micro-RNAs (miRNAs), extracellular vesicles (EVs), metabolomics, metabolites and the microbiome may prove to be useful in developing a more comprehensive panel that addresses the limitations of using a single biomarker. Therefore, more research with recent technological and statistical approaches is needed to identify novel and useful diagnostic and prognostic biomarker tools in MS.

Update on Multiple Sclerosis Molecular Biomarkers to Monitor Treatment Effects

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease of the central nervous system characterized by broad inter- and intraindividual heterogeneity. The relapse rate, disability progression, and lesion load assessed through MRI are used to detect disease activity and response to treatment. Although it is possible to standardize these characteristics in larger patient groups, so far, this has been difficult to achieve in individual patients. Easily detectable molecular biomarkers can be powerful tools, permitting a tailored therapy approach for MS patients. However, only a few molecular biomarkers have been routinely used in clinical practice as the validation process, and their transfer into clinical practice takes a long time. This review describes the characteristics of an ideal MS biomarker, the challenges of establishing new biomarkers, and promising molecular biomarkers from blood or CSF samples used to monitor MS treatment effects in clinical practice.

Plasma Protein Levels Analysis in Multiple Sclerosis Sardinian Families Identified C9 and CYP24A1 as Candidate Biomarkers

Here we investigate protein levels in 69 multiple sclerosis (MS) cases and 143 healthy controls (HC) from twenty Sardinian families to search for promising biomarkers in plasma. Using antibody suspension bead array technology, the plasma levels of 56 MS-related proteins were obtained. Differences between MS cases and HC were estimated using Linear Mixed Models or Linear Quantile Mixed Models. The proportion of proteins level variability, explained by a set of 119 MS-risk SNPs as to the literature, was also quantified. Higher plasma C9 and CYP24A1 levels were found in MS cases compared to HC (p < 0.05 after Holm multiple testing correction), with protein level differences estimated as, respectively, 0.53 (95% CI: 0.25, 0.81) and 0.42 (95% CI: 0.19, 0.65) times plasma level standard deviation measured in HC. Furthermore, C9 resulted in both statistically significantly higher relapsing-remitting MS (RRMS) and secondary-progressive MS (SPMS) compared to HC, with SPMS showing the highest differences. Instead, CYP24A1 was statistically significantly higher only in RRMS as compared to HC. Respectively, 26% (95% CI: 10%, 44%) and 16% (95% CI: 9%, 39%) of CYP24A1 and C9 plasma level variability was explained by known MS-risk SNPs. Our results highlight C9 and CYP24A1 as potential biomarkers in plasma for MS and allow us to gain insight into molecular disease mechanisms.

Molecular biomarkers in multiple sclerosis

Multiple sclerosis (MS) is a highly heterogenous disease regarding radiological, pathological, and clinical characteristics and therapeutic response, including both the efficacy and safety profile of treatments. Accordingly, there is a high demand for biomarkers that sensitively and specifically apprehend the distinctive aspects of the MS heterogeneity, and that can aid in better understanding of the disease diagnosis, prognosis, prediction of the treatment response, and, finally, in the development of new treatments. Currently, clinical characteristics (e.g., relapse rate and disease progression) and magnetic resonance imaging play the most important role in the clinical classification of MS and assessment of its course. Molecular biomarkers (e.g., immunoglobulin G (IgG) oligoclonal bands, IgG index, anti-aquaporin-4 antibodies, neutralizing antibodies against interferon-beta and natalizumab, anti-varicella zoster virus and anti-John Cunningham (JC) virus antibodies) complement these markers excellently. This review provides an overview of exploratory, validated and clinically useful molecular biomarkers in MS which are used for prediction, diagnosis, disease activity and treatment response.

Update on treatment in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. In recent years, many disease-modifying therapies (DMT) have been approved for MS treatment. For this reason, a profound knowledge of the characteristics and indications of the available compounds is required to tailor the therapeutic strategy to the individual patient characteristics. This should include the mechanism of action and pharmacokinetic of the drug, the safety and efficacy profile provided by clinical trials, as well as the understanding of possible side effects. Moreover, the evolving knowledge of the disease is paving the way to new and innovative therapeutic approaches, as well as the development of new biomarkers to monitor the therapeutic response and to guide the clinician's therapeutic choices. In this review we provide a comprehensive overview on currently approved therapies in MS and the emerging evidence-based strategies to adopt for initiating, monitoring, and eventually adapting a therapeutic regimen with DMT.

Prevention and management of adverse effects of disease modifying treatments in multiple sclerosis

PURPOSE OF REVIEW

To summarize the currently known side effects of the approved therapies of multiple sclerosis and to suggest monitoring procedures.

RECENT FINDINGS

The progress in the treatment of multiple sclerosis with new very effective therapies is accompanied by a number of side effects. Some of these have already been described in the approval studies, but some only after approval in a real world situation. The reason for this is the short duration of the clinical studies, the very heterogeneous patient profile in the real world setting with a number of comorbidities, pretherapies, and wider age range. The side effects may occur during application of therapies or afterwards during the course of the treatment. The side effects may range from mild infections, mild laboratory abnormalities, secondary autoimmune diseases to life-threatening side effects such as progressive multifocal leukoencephalopathy.

SUMMARY

It has to be pointed out that these side effects are not to be considered as final and neurologists should be vigilant against new unknown side effects. The doctor should be aware of these undesirable effects, should weigh the benefits of the therapies against the risks, but at the same time she/he should keep in mind that multiple sclerosis can be a very disabling disease if not treated properly.

Comparison of Therapies in MS Patients After the First Demyelinating Event in Real Clinical Practice in the Czech Republic: Data From the National Registry ReMuS

Background: Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system. Well-established drugs used for MS patients after the first demyelinating event in the Czech Republic include glatiramer acetate (GA), interferon beta-1a (IFNβ-1a), IFN beta-1b (IFNβ-1b), peginterferon beta-1a (peg-IFNβ-1a), and teriflunomide.

Objective: The objective of this observational study was to compare the effectiveness of the abovementioned drugs in patients with MS who initiated their therapy after the first demyelinating event. Patients were followed for up to 2 years in real clinical practice in the Czech Republic.

Methods: A total of 1,654 MS patients treated after the first demyelinating event and followed up for 2 years were enrolled. Evaluation parameters (endpoints) included the annualized relapse rate (ARR), time to next relapse, change in the Expanded Disability Status Scale (EDSS) score, and time of confirmed disease progression (CDP). When patients ended the therapy before the observational period, the reason for ending the therapy among different treatments was compared.

Results: No significant difference was found among the groups of patients treated with IFNβ-1a/1b, GA, or teriflunomide for the following parameters: time to the first relapse, change in the EDSS score, and the proportion of patients with CDP. Compared to IFNβ-1a (44 mcg), a significant increase in the percentage of relapse-free patients was found for GA, but this treatment effect was not confirmed by the validation analysis. Compared to the other drugs, there was a significant difference in the reasons for terminating GA therapy.

Conclusion: Small differences were found among GA, IFNβ and teriflunomide therapies, with no significant impact on the final outcome after 2 years. Therefore, in clinical practice, we recommend choosing the drug based on individual potential risk from long-term therapy and on patient preferences and clinical characteristics.

Interferon β-1a (IFNβ-1a) in COVID-19 patients (INTERCOP): study protocol for a randomized controlled trial

BACKGROUND

Pharmacological therapies of proven efficacy in coronavirus disease 2019 (COVID-19) are still lacking. We have identified IFNβ-1a as the most promising drug to be repurposed for COVID-19. The rationale relies on the evidence of IFNβ anti-viral activity in vitro against SARS-CoV-2 and animal models resembling SARS-CoV-2 infection and on a recent clinical trial where IFNβ was indicated as the key component of a successful therapeutic combination.

METHODS

This is a randomized, controlled, open-label, monocentric, phase II trial (INTERCOP trial). One hundred twenty-six patients with positive swab detection of SARS-CoV-2, radiological signs of pneumonia, and mild-to-moderate disease will be randomized 2:1 to IFNβ-1a in addition to standard of care vs standard of care alone. No other anti-viral drugs will be used as part of the regimens, both in the control and the intervention arms. IFNβ-1a will be administered subcutaneously at the dose of 44 mcg (equivalent to 12 million international units) three times per week, at least 48 h apart, for a total of 2 weeks. The primary outcome is the time to negative conversion of SARS-CoV-2 nasopharyngeal swabs. Secondary outcomes include improvement or worsening in a clinical severity score measured on a 7-point ordinal scale (including transfer to intensive care unit and death), oxygen- and ventilator-free days, mortality, changes in pulmonary computed tomography severity score, hospital stay duration, reduction of viral load measured on nasopharyngeal swabs, number of serious adverse events, and changes in biochemical markers of organ dysfunction. Exploratory outcomes include blood cell counts, cytokine and inflammatory profile, peripheral mRNA expression profiles of interferon-stimulated genes, and antibodies to SARS-CoV-2 and to IFNβ-1a. INTERCOP is the first study to specifically investigate the clinical benefits of IFNβ-1a in COVID-19 patients.

DISCUSSION

Potential implications of this trial are multifaceted: should the primary outcome be fulfilled and the treatment be safe, one may envisage that IFNβ-1a be used to reduce the infectivity of patients with mild-to moderate disease. In case IFNβ-1a reduced the duration of hospital stay and/or ameliorated the clinical status, it may become a cornerstone of COVID-19 treatment.

TRIAL REGISTRATION

EudraCT 2020-002458-25. Registered on May 11, 2020 ClinicalTrials.gov Identifier: NCT04449380.

Long-Term Consequences of High Titer Neutralizing Antibodies to Interferon-β in Multiple Sclerosis

Background

Neutralizing anti-drug antibodies (NAbs) to interferon beta (IFNβ) develop in up to 47% of multiple sclerosis (MS) treated patients inhibiting treatment effect of IFNβ. However, the long-term effect of NAbs remain unknown.

Objective

To investigate the long-term consequences of high titer NAbs to IFNβ on disease activity and progression in MS patients.

Methods

An observational study including data from all IFNβ treated relapsing remitting MS patients with sufficient NAb test results from the Swedish MS registry. Patients were classified into either confirmed ‘high titer’ or ‘persistent negative’ groups and analyzed for differences in disease activity and progression over time.

Results

A total of 197 high-titer and 2907 persistent negative patients with 19969.6 follow up years of data were included. High titer NAbs were associated with a higher degree of disease activity at baseline. However, even when accounting for this, the presence of high titer NAbs were also associated with higher disease activity during IFNβ treatment. This persisted even after the next DMT start, suggesting that earlier high titers may partially reduce the effect of later treatments. No difference was found in confirmed disability progression.

Conclusion

High titer NAbs to IFNβ are associated with higher disease activity, persisting even after IFNβ discontinuation or switch. These results support use of highly efficient treatment earlier in patients with active disease, to avoid these complications.

Using Serum Metabolomics to Predict Development of Anti-drug Antibodies in Multiple Sclerosis Patients Treated With IFNβ

Background: Neutralizing anti-drug antibodies (ADA) can greatly reduce the efficacy of biopharmaceuticals used to treat patients with multiple sclerosis (MS). However, the biological factors pre-disposing an individual to develop ADA are poorly characterized. Thus, there is an unmet clinical need for biomarkers to predict the development of immunogenicity, and subsequent treatment failure. Up to 35% of MS patients treated with beta interferons (IFNβ) develop ADA. Here we use machine learning to predict immunogenicity against IFNβ utilizing serum metabolomics data. Methods: Serum samples were collected from 89 MS patients as part of the ABIRISK consortium-a multi-center prospective study of ADA development. Metabolites and ADA were quantified prior to and after IFNβ treatment. Thirty patients became ADA positive during the first year of treatment (ADA+). We tested the efficacy of six binary classification models using 10-fold cross validation; k-nearest neighbors, decision tree, random forest, support vector machine and lasso (Least Absolute Shrinkage and Selection Operator) logistic regression with and without interactions. Results: We were able to predict future immunogenicity from baseline metabolomics data. Lasso logistic regression with/without interactions and support vector machines were the most successful at identifying ADA+ or ADA- cases, respectively. Furthermore, patients who become ADA+ had a distinct metabolic response to IFNβ in the first 3 months, with 29 differentially regulated metabolites. Machine learning algorithms could also predict ADA status based on metabolite concentrations at 3 months. Lasso logistic regressions had the greatest proportion of correct classifications [F1 score (accuracy measure) = 0.808, specificity = 0.913]. Finally, we hypothesized that serum lipids could contribute to ADA development by altering immune-cell lipid rafts. This was supported by experimental evidence demonstrating that, prior to IFNβ exposure, lipid raft-associated lipids were differentially expressed between MS patients who became ADA+ or remained ADA-. Conclusion: Serum metabolites are a promising biomarker for prediction of ADA development in MS patients treated with IFNβ, and could provide novel insight into mechanisms of immunogenicity.

Effectiveness of glatiramer acetate in neutralizing antibody-positive patients previously treated with interferon-β

BACKGROUND

Some patients with multiple sclerosis who are treated with interferon-β(IFNβ) develop neutralizing antibodies (NAbs), which reduce or abolish the therapeutic effects of the treatment. These patients are usually switched to a non-IFNβ treatment, such as glatiramer acetate (GA). It is unknown whether a patient's previous disease activity in combination with their NAb-status can provide further insights on their risk of future disease activity. Consequently, we investigated treatment outcomes in patients switching from IFNβ to GA according to NAb-status and clinical disease activity, while on IFNβ.

METHODS

We identified all patients switching from IFNβ to GA and having information on NAb-status from the Danish Multiple Sclerosis Registry and compared treatment outcomes while on GA according to previous disease activity and the presence of NAbs.

RESULTS

We included 568 patients in the study: 107 NAb-negative patients switched due to adverse events (group 1), 24 NAb-negative patients switched with disease activity (group 2), 397 NAb-positive patients switched without disease activity (group 3) and 40 NAb-positive patients switched with disease activity (group 4). Compared to the reference (group 1), group 2 had an increased risk of future relapses (HR 1.79 95% Confidence interval (CI): 1.00-3.19). Group 3 showed a trend of a lower risk of future relapses (HR 0.74, 95%CI: 0.53-1.04). Group 4 had, on average, a similar risk of future relapses (HR 1.15 95% CI: 0.69-1.92). Similarly, group 2 had a higher probability of treatment discontinuation due to disease activity compared to the other groups.

CONCLUSION

While on GA, patients switched from IFNβ in the context of disease activity and no NAbs had the highest risk of future disease activity, while NAb positive patients without previous activity had the lowest. We did not find any average difference between NAb-positive patients switching in a context of disease activity and NAb-negative patients switched due to adverse events, although carefulness in the interpretation of this result is advised.

Established and Emerging Immunological Complications of Biological Therapeutics in Multiple Sclerosis

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

Molecular biomarkers in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory-neurodegenerative disease of the central nervous system presenting with significant inter- and intraindividual heterogeneity. However, the application of clinical and imaging biomarkers is currently not able to allow individual characterization and prediction. Complementary, molecular biomarkers which are easily quantifiable come from the areas of immunology and neurobiology due to the causal pathomechanisms and can excellently complement other disease characteristics. Only a few molecular biomarkers have so far been routinely used in clinical practice as their validation and transfer take a long time. This review describes the characteristics that an ideal MS biomarker should have and the challenges of establishing new biomarkers. In addition, clinically relevant and promising biomarkers from the blood and cerebrospinal fluid are presented which are useful for MS diagnosis and prognosis as well as for the assessment of therapy response and side effects.

Long-Term Treatment Strategies of Pediatric Multiple Sclerosis, Including the use of Disease Modifying Therapies

Multiple sclerosis (MS) presenting in the pediatric years can lead to landmark disability levels younger in life than adult onset MS and so therefore early and effective treatment remains paramount for long-term outcomes. The goals of MS therapeutics in adults have widened to address multiple mechanisms: anti-inflammatory, neuroprotective, and myelin repair, yet the optimal paradigm for MS therapies in the pediatric population is not known. Pediatric onset MS add complexities due to the ongoing development of the central nervous system and the immune system. Clinical trials have led to an increasing number of pharmaceutical therapies for adult onset MS (AOMS), one POMS randomized controlled trial is completed and other trials are ongoing, yet due to the low prevalence of POMS, the dynamic landscape and risk management of the MS disease modifying therapies (DMT) it remains more difficult to complete trials in POMS. There is consensus that controlled clinical trials leading to appropriate and safe therapies for POMS are important for a multitude of reasons that include unique pediatric pharmacokinetics, short and long-term safety, developmental issues, clinical benefits, and regulatory approval. This review will focus on new treatment goals, paradigm, strategies, monitoring, compliance, and products in the long-term treatment of POMS. The discussion will focus on these new concepts and the published data related to DMT use in POMS. This review provides significant insight into new concepts of treatment goals and current approaches to enhance the lives of the POMS patients now and in the future.

Different Interferon Beta Preparations Induce the Same Qualitative Immune Response in Human Skin

Interferon beta (IFNβ) is used as a first-line treatment for multiple sclerosis (MS) and is injected intramuscularly or subcutaneously (s.c.). The subcutaneous route is considered more immunogenic as it is associated with increased antidrug antibody-positive patients. The skin contains dendritic cells (DCs) and it is unclear whether these contribute to immunogenicity. To assess the effect of IFNβ on skin-resident cells, IFNβ was injected intradermally (i.d.) ex vivo using a human skin explant model or s.c. in vivo in MS patients. Ex vivo, intradermal IFNβ injections reduced migration and enhanced surface CD86 expression of dermal DCs, and an increased expression of HLA-DR⁺ was observed in skin biopsies taken after subcutaneous IFNβ injection (in vivo). In both models, IFNβ elevated the expression of several inflammatory cytokines when compared to the control biopsies. Our results show that 3 different IFNβ preparations, normalized in dose and injection site, induce similar immune responses, suggesting that the differences in immunogenicity are likely due to the route and frequency of administration.

Biomarkers in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic neurodegenerative autoimmune disease with a complex clinical course characterized by inflammation, demyelination, and axonal degeneration. Diagnosis of MS most commonly includes finding lesions in at least two separate areas of the central nervous system (CNS), including the brain, spinal cord, and optic nerves. In recent years, there has been a remarkable increase in the number of available treatments for MS. An optimal treatment is usually based on a personalized approach determined by an individual patient's prognosis and treatment risks. Biomarkers that can predict disability progression, monitor ongoing disease activity, and assess treatment response are integral in making important decisions regarding MS treatment. This review describes MS biomarkers that are currently being used in clinical practice; it also reviews and consolidates published findings from clinically relevant potential MS biomarkers in recent years. The work also discusses the challenges of validating and application of biomarkers in MS clinical practice.

Interferon β for Multiple Sclerosis

Despite that the availability of new therapeutic options has expanded the multiple sclerosis (MS) disease-modifying therapy arsenal, interferon β (IFN-β) remains an important therapy option in the current decision-making process. This review will summarize the present knowledge of IFN-β mechanism of action, the overall safety, and the short- and long-term efficacy of its use in relapsing remitting MS and clinically isolated syndromes. Data on secondary progressive MS is also provided, although no clear benefit was identified.

Drug Efficacy Monitoring in Pharmacotherapy of Multiple Sclerosis With Biological Agents

Multiple sclerosis is a heterogenous disease. Although several EMA-approved disease-modifying treatments including biopharmaceuticals are available, their efficacy is limited, and a certain percentage of patients are always nonresponsive. Drug efficacy monitoring is an important tool to identify these nonresponsive patients early on. Currently, detection of antidrug antibodies and quantification of biological activity are used as methods of efficacy monitoring for interferon beta and natalizumab therapies. For natalizumab and alemtuzumab treatments, drug level quantification could be an essential component of the overall disease management. Thus, utilization and development of strategies to determine treatment response are vital aspects of multiple sclerosis management given the tremendous clinical and economic promise of this tool.

Managing the side effects of multiple sclerosis therapy: pharmacotherapy options for patients

INTRODUCTION

Multiple sclerosis (MS) is an immune-mediated and neurodegenerative disease with an unpredictable outcome. Immune-modulatory treatment aims at decreasing long-term disability. With the increasing number of treatment options, it is essential to fully digest the possible side effects of the available therapeutics and to monitor patients is essential.

AREAS COVERED

All approved disease-modifying drugs (DMD) for MS are discussed in this review. Mode of action, adverse effects, reported risks for infections and malignancies, and pregnancy related issues are discussed in the review. The authors also provide suggestions for monitoring therapy. For all approved DMDs the pivotal studies have been included for possible side effects, as well as reports by health authorities. For this manuscript, PubMed was checked for reports on side effects for various drugs.

EXPERT OPINION

Treatment options in MS are manifold, each carrying different risks. The safety-risk profile for approved agents is favorable. Knowing and monitoring these possible side effects is essential to minimize risks associated with treatment. Presently, the long-term experience for some of these therapies is missing and this must be addressed.

Effect of HLA-DRB1 alleles and genetic variants on the development of neutralizing antibodies to interferon beta in the BEYOND and BENEFIT trials

BACKGROUND

Treatment of multiple sclerosis (MS) with interferon β can lead to the development of antibodies directed against interferon β that interfere with treatment efficacy. Several observational studies have proposed different HLA alleles and genetic variants associated with the development of antibodies against interferon β.

OBJECTIVE

To validate the proposed genetic markers and to identify new markers.

METHODS

Associations of genetic candidate markers with antibody presence and development were examined in a post hoc analysis in 941 patients treated with interferon β-1b in the Betaferon^® Efficacy Yielding Outcomes of a New Dose (BEYOND) and BEtaseron^®/BEtaferon^® in Newly Emerging multiple sclerosis For Initial Treatment (BENEFIT) prospective phase III trials. All patients were treated with interferon β-1b for at least 6 months. In addition, a genome-wide association study was conducted to identify new genetic variants.

RESULTS

We confirmed an increased risk for carriers of HLA-DRB1*04:01 (odds ratio (OR) = 3.3, p = 6.9 × 10^-4) and HLA-DRB1*07:01 (OR = 1.8, p = 3.5 × 10^-3) for developing neutralizing antibodies (NAbs). Several additional, previously proposed HLA alleles and genetic variants showed nominally significant associations. In the exploratory analysis, variants in the HLA region were associated with NAb development at genome-wide significance (OR = 2.6, p = 2.30 × 10^-15).

CONCLUSION

The contribution of HLA alleles and HLA-associated single-nucleotide polymorphisms (SNPs) to the development and titer of antibodies against interferon β was confirmed in the combined analysis of two multi-national, multi-center studies.

Neutralizing Antibodies Against Interferon-Beta in Korean Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE

Patients treated with interferon-beta (IFN-β) can develop neutralizing antibodies (NAbs) against IFN-β that can negatively affect the therapeutic response. This study assessed the prevalence of NAbs and the impact of NAb positivity on the therapeutic response to IFN-β in Korean patients with multiple sclerosis (MS).

METHODS

This was a multicenter study involving 150 MS patients from 9 Korean medical centers who were treated with IFN-β for at least 6 months. Sera that had not been influenced by acute treatment were assessed for NAbs using a luciferase reporter gene assay. To evaluate the association between persistent positivity for NAbs and disease activity, NAbs were tested at 2 different time points in 75 of the 150 patients. Disease activity was defined as the presence of clinical exacerbations and/or active MRI lesions during a 1-year follow-up after NAb positivity was confirmed.

RESULTS

NAbs were found in 39 of the 150 (26%) MS patients: 30 of the 85 (35%) who were treated with subcutaneous IFN-β-1b, 9 of the 60 (15%) who were treated with subcutaneous IFN-β-1a, and 0 of the 5 (0%) who were treated with intramuscular IFN-β-1a. Thirty of the 39 patients exhibiting NAb positivity were tested at different time points, and 20 of them exhibited persistent NAb positivity. Disease activity was observed more frequently in patients with persistent NAb positivity than in those with transient positivity or persistent negativity [16/20 (80%) vs. 4/55 (7%), respectively; p<0.001]. When disease activity was compared between patients with persistent and transient NAb positivity, the difference was unchanged and remained statistically significant [16/20 (80%) vs. 2/10 (20%), p=0.004].

CONCLUSIONS

These results further support that persistent NAb positivity is associated with disease activity in MS patients treated with IFN-β.

The clinical perspective: How to personalise treatment in MS and how may biomarkers including imaging contribute to this?

BACKGROUND

Multiple sclerosis (MS) is a highly heterogeneous disease, both in its course and in its response to treatments. Effective biomarkers may help predict disability progression and monitor patients' treatment responses.

OBJECTIVE

The aim of this review was to focus on how biomarkers may contribute to treatment individualisation in MS patients.

METHODS

This review reflects the content of presentations, polling results and discussions on the clinical perspective of MS during the first and second Pan-European MS Multi-stakeholder Colloquia in Brussels in May 2014 and 2015.

RESULTS

In clinical practice, magnetic resonance imaging (MRI) measures play a significant role in the diagnosis and follow-up of MS patients. Together with clinical markers, the rate of MRI-visible lesion accrual once a patient has started treatment may also help to predict subsequent treatment responsiveness. In addition, several molecular (immunological, genetic) biomarkers have been established that may play a role in predictive models of MS relapses and progression. To reach personalised treatment decisions, estimates of disability progression and likely treatment response should be carefully considered alongside the risk of serious adverse events, together with the patient's treatment expectations.

CONCLUSION

Although biomarkers may be very useful for individualised decision making in MS, many are still research tools and need to be validated before implementation in clinical practice.

Immunomodulation in multiple sclerosis: promises and pitfalls

Multiple sclerosis (MS) afflicts about 2.5 million people globally and poses a major personal and socioeconomic burden. The recognition of MS as an inflammatory disease, characterized by infiltration of immune cells into the central nervous system, has spurred research into the autoimmune etiology of the condition and has provided the rationale for its treatment through immunomodulation. Experience with immunotherapies in MS to date has suggested a disparity between the observed immune cell infiltration and the progressive loss of neurons. However, recent clinical efforts are providing new insights into progressive MS that once again place the immune system at center stage. This article reviews the main mechanisms of MS immunopathogenesis, and the benefits, risks and challenges of immunomodulatory treatments for the disease.

Cross-reactivity of antibodies against interferon beta in multiple sclerosis patients and interference of the JAK-STAT signaling pathway

Interferon beta (IFNβ) therapy has immunogenic properties and induces the development of neutralizing antibodies (NAbs). From the extensive literature focused in the development of NAbs in multiple sclerosis (MS) patients, their ability to cross-react has been deficiently evaluated, despite having important consequences in the clinical practice. Here, the relation between the cross-reactivity and the NAbs titers has been evaluated in MS patients, by inhibition of the antiviral activity of IFNβ by bioassay and through the interference with the activation of the IFNß pathway (JAK-STAT), by phosphoflow. Thus, patients with intermediate-high titers of NAbs, determined by bioassay, had a 79-fold increased risk of cross-reactivity compared to patients with low titers. The cross-reactivity is also demonstrated because NAbs positive sera were able to decrease significantly the activation of pSTAT1 achieved by other different IFNβ molecules in the cells patients. Besides, a linear relationship between the STAT1 phosphorylation and NAbs titers was found. The study demonstrates that cross-reactivity increases with the titer of antibodies, which has important implications in clinical practice when switching the treatment. The direct relationship between the NAbs titer and the activation of STAT1 suggest that its determination could be an indirect method to identify the presence of NAbs.

Prevalence of neutralising antibodies to interferon-beta and clinical response in Chinese patients with relapsing multiple sclerosis

Background

There are no data on neutralising antibodies to interferon-beta and its clinical implications in Chinese patients with multiple sclerosis (MS).

Objectives

The objectives of this study were to investigate the prevalence of neutralising antibodies among Chinese patients with relapsing MS receiving interferon-beta (1a or 1b) and to study the association between neutralising antibodies and the clinical-radiological response.

Methods

We performed a cross-sectional study on MS patients who received interferon-beta for 9 months or more, and evaluated the clinical response by relapses and magnetic resonance imaging lesions. Blood samples were evaluated for myxovirus resistance protein A (MxA) gene expression by polymerase chain reaction, anti-interferon-beta binding antibodies by enzyme-linked immunosorbent assay, and neutralising antibodies by cell-based MxA protein induction and luciferase reporter gene assays. Assay performances were evaluated by receiver operating characteristic analysis.

Results

Among 78 subjects recruited, 61/77 (79%) had anti-interferon-beta binding antibodies, and 22/78 (28%) had neutralising antibodies by MxA protein induction assay. The presence of high-titre neutralising antibodies was associated with poor clinical outcome (odds ratio 6.1, 95% confidence interval 1.5–25.6, P = 0.013). The sensitivity and specificity for neutralising antibodies using MxA gene expression assay (cut-off 0.20) was 80% and 68%, respectively (area under the curve 0.71).

Conclusions

Neutralising antibodies are associated with poor clinical outcome in Chinese patients with relapsing MS. MxA gene expression and protein induction assays are complimentary assays for neutralising antibody detection.

Practical recommendations for the use of therapeutic drug monitoring of biopharmaceuticals in inflammatory diseases

Biopharmaceuticals directed against tumor necrosis factor-alpha, integrins, interleukins, interferons and their receptors have become key agents for the management of inflammatory diseases in the fields of gastroenterology, rheumatology, dermatology and neurology. However, response to these treatments is far from optimal. Therapeutic failure has been attributed in part to inadequate serum concentrations of the drug and the formation of antidrug antibodies (ADA). Therapeutic drug monitoring (TDM) based on drug concentrations and ADA represents a pharmacologically sound tool for guiding dosage adjustments to optimize exposure. Although becoming standard practice in tertiary care centers, the widespread accessibility and recognition of TDM is hindered by several hurdles, including a lack of education of health care providers on TDM. In this paper, the Monitoring of monoclonal Antibodies Group in Europe (MAGE) provides an introduction on the fundamental principles of the concept of TDM, aiming to educate clinicians and assist them in the process of implementing TDM of anti-inflammatory biopharmaceuticals.

Safety concerns and risk management of multiple sclerosis therapies

Currently, more than ten drugs have been approved for treatment of relapsing-remitting multiple sclerosis (MS). Newer treatments may be more effective, but have less favorable safety record. Interferon-β preparations and glatiramer acetate treatment require frequent subcutaneous or intramuscular injections and are only moderately effective, but have very rarely life-threatening adverse effects, whereas teriflunomide and dimethyl fumarate are administered orally and have equal or better efficacy, but have more potentially severe adverse effects. The highly effective therapies fingolimod, natalizumab, daclizumab, and alemtuzumab have more serious adverse effects, some of which may be life-threatening. The choice between drugs should be based on a benefit-risk evaluation and tailored to the individual patient's requirements in a dialogue between the patient and treating neurologist. Patients with average disease activity can choose between dimethyl fumarate and teriflunomide or the "old injectable." Patients with very active MS may choose a more effective drug as the initial treatment. In case of side effects on one drug, switch to another drug can be tried. Suboptimal effect of the first drug indicates escalation to a highly efficacious drug. A favorable benefit-risk balance can be maintained by appropriate patient selection and appropriate risk management on therapy. New treatments will within the coming 1-2 years change our current treatment algorithm for relapsing-remitting MS.

Development and Validation of an Enzyme-Linked Immunosorbent Assay for the Detection of Binding Anti-Drug Antibodies against Interferon Beta

Objective

To develop and validate a method for the detection of binding anti-drug antibodies (ADAs) against interferon beta (IFN-β) in human serum as part of a European initiative (ABIRISK) aimed at the prediction and analysis of clinical relevance of anti-biopharmaceutical immunization to minimize the risk.

Method

A two-tiered bridging enzyme-linked immunosorbent assay (ELISA) format was selected and validated according to current recommendations. Screening assay: ADA in serum samples form complexes with immobilized IFN-β and biotinylated IFN-β, which are then detected using HRP labeled Streptavidin and TMB substrate. Confirmation assay: Screen “putative positive” samples are tested in the presence of excess drug (preincubation of sera with 0.3 µg/mL of soluble IFN-β) and percentage of inhibition is calculated.

Results

The assay is precise, and the sensitivity of the assay was confirmed to be 26 ng/mL using commercially available polyclonal rabbit antihuman IFN-β in human sera as the positive control.

Conclusion

An ultrasensitive ELISA for IFN-β-binding ADA testing has been validated. This will form the basis to assess anti-biopharmaceutical immunization toward IFN-β with regards to its clinical relevance and may allow for the development of predictive tools, key aims within the ABIRISK consortium.

Persistency of Neutralizing Anti-Interferon-β Antibodies in Patients with Multiple Sclerosis Treated with Subcutaneous Interferon-β Depends on Antibody Titers, IgG Subclasses, and Affinity Maturation

Neutralizing antibodies may affect interferon (IFN)-β treatment efficacy, but mechanisms of neutralizing anti-drug antibody (ADA) evolution are not fully elucidated. We investigated the relationship between ADA titers, IgG subclass profile, and binding affinity with the development and persistency of neutralizing ADA in relapsing-remitting multiple sclerosis (MS) patients treated with subcutaneous IFN-β. A total of 94 patients, who had blood sampling at months 6, 12, 24, and 36 during IFN-β therapy, were included into this retrospective study and stratified to the following: non-neutralizing, transient, and persistent neutralizing ADA status. Patients without or with transient neutralizing ADA displayed predominantly IgG₁ and IgG₃ subclasses, lower ADA titers, and antibody binding affinity compared with patients having persistent neutralizing ADA, in whom the predominant IgG subclasses were IgG₂ and IgG₄. Overall, ADA binding affinity positively correlated with IgG₄ and neutralizing ADA titers, but negatively with IgG₃ titers. Persistency of neutralizing ADA was predicted by their titers at month 24 and month 36 of treatment and by an increase of antibody affinity within the second year of IFN-β treatment. The humoral immune response to IFN-β observed in MS patients as a result of IFN-β therapy is a multifactorial process that is influenced by ADA titers, affinity maturation, and IgG subclass switching.

MxA mRNA decrease preceding NAb detection in IFNβ-treated MS patients

BACKGROUND

Multiple sclerosis (MS) patients treated with interferon beta (IFNβ) are at risk of a declining response to treatment because of the production of IFNβ-neutralizing antibodies (NAbs). The expression of Myxovirus resistance protein A (MxA) mRNA is regarded as a marker of IFNβ bioactivity.

AIMS

The aim of this study was to analyze the kinetics of MxA mRNA expression during long-term IFNβ treatment and assess its relationship to NAb production.

METHODS

A prospective, observational, open-label, non-randomized study was designed in multiple sclerosis patients starting IFNβ treatment. NAbs and MxA mRNA were monitored every six months.

RESULTS

119 patients were consecutively enrolled and 107 were included in the final analysis. Both the presence of NAbs and a decrease in MxA mRNA below the cut off were revealed in 15 patients, however, in six patients (40%) positivity for NAbs was preceded by the decrease in MxA mRNA. In addition, a further six patients showing a decline in MxA mRNA did not have detectable NAbs.

CONCLUSION

Our data indicate that quantification of MxA mRNA is a more sensitive identifier of loss of IFNβ efficacy than the NAb positivity.

Optimization and stratification of multiple sclerosis treatment in fast developing economic countries: a perspective from Qatar

OBJECTIVE

The introduction of disease-modifying therapies (DMTs) - with varying degrees of efficacy for reducing annual relapse rate and disability progression - has considerably transformed the therapeutic landscape of relapsing-remitting multiple sclerosis (RRMS). We aim to develop rational evidence-based treatment recommendations and algorithms for the management of clinically isolated syndrome (CIS) and RRMS that conform to the healthcare system in a fast-developing economic country such as Qatar.

RESEARCH DESIGN AND METHODS

We conducted a systematic review using a comprehensive search of MEDLINE, PubMed, and Cochrane Database of Systematic Reviews (1 January 1990 through 30 September 2016). Additional searches of the American Academy of Neurology and European Committee for Treatment and Research in Multiple Sclerosis abstracts from 2012 through 2016 were performed, in addition to searches of the Food and Drug Administration and European Medicines Agency websites to obtain relevant safety information on these DMTs.

RESULTS

For each of the DMTs, the mode of action, efficacy, safety and tolerability are briefly discussed. To facilitate the interpretation, the efficacy data of the pivotal phase III trials are expressed by their most clinically useful measure of therapeutic efficacy, the number needed to treat (NNT). In addition, an overview of head-to-head trials in RRMS is provided as well as a summary of the several different RRMS management strategies (lateral switching, escalation, induction, maintenance and combination therapy) and the potential role of each DMT. Finally, algorithms were developed for CIS, active and highly active or rapidly evolving RRMS and subsequent breakthrough disease or suboptimal treatment response while on DMTs. The benefit-to-risk profiles of the DMTs, taking into account patient preference, allowed the provision of rational and safe patient-tailored treatment algorithms.

CONCLUSIONS

Recommendations and algorithms for the management of CIS and RRMS have been developed relevant to the healthcare system of this fast-developing economic country.

Clinical practice of analysis of anti-drug antibodies against interferon beta and natalizumab in multiple sclerosis patients in Europe: A descriptive study of test results

Antibodies against biopharmaceuticals (anti-drug antibodies, ADA) have been a well-integrated part of the clinical care of multiple sclerosis (MS) in several European countries. ADA data generated in Europe during the more than 10 years of ADA monitoring in MS patients treated with interferon beta (IFNβ) and natalizumab have been pooled and characterized through collaboration within a European consortium. The aim of this study was to report on the clinical practice of ADA testing in Europe, considering the number of ADA tests performed and type of ADA assays used, and to determine the frequency of ADA testing against the different drug preparations in different countries. A common database platform (tranSMART) for querying, analyzing and storing retrospective data of MS cohorts was set up to harmonize the data and compare results of ADA tests between different countries. Retrospective data from six countries (Sweden, Austria, Spain, Switzerland, Germany and Denmark) on 20,695 patients and on 42,555 samples were loaded into tranSMART including data points of age, gender, treatment, samples, and ADA results. The previously observed immunogenic difference among the four IFNβ preparations was confirmed in this large dataset. Decreased usage of the more immunogenic preparations IFNβ-1a subcutaneous (s.c.) and IFNβ-1b s.c. in favor of the least immunogenic preparation IFNβ-1a intramuscular (i.m.) was observed. The median time from treatment start to first ADA test correlated with time to first positive test. Shorter times were observed for IFNβ-1b-Extavia s.c. (0.99 and 0.94 years) and natalizumab (0.25 and 0.23 years), which were introduced on the market when ADA testing was already available, as compared to IFNβ-1a i.m. (1.41 and 2.27 years), IFNβ-1b-Betaferon s.c. (2.51 and 1.96 years) and IFNβ-1a s.c. (2.11 and 2.09 years) which were available years before routine testing began. A higher rate of anti-IFNβ ADA was observed in test samples taken from older patients. Testing for ADA varies between different European countries and is highly dependent on the policy within each country. For drugs where routine monitoring of ADA is not in place, there is a risk that some patients remain on treatment for several years despite ADA positivity. For drugs where a strategy of ADA testing is introduced with the release of the drug, there is a reduced risk of having ADA positive patients and thus of less efficient treatment. This indicates that potential savings in health cost might be achieved by routine analysis of ADA.

Immunogenicity of Human Interferon-Beta-Containing Pharmaceuticals

Multiple sclerosis is a severe autoimmune disease with inflammatory component that continues to be resistant to treatment. One of the approaches retarding its progression is based on using nonspecific therapy with human interferon-beta (IFN-β)-containing pharmaceuticals. Neutralizing antibodies (NAbs) against genetically engineered pharmaceuticals developed by the patient's immune system, which reduce their therapeutic and biological activity, pose a serious problem. Cell lines sensitive to IFN-β activity also quantifying NAb level are applied because direct measurement of IFN-β antiviral activity is complicated. This study was aimed at standardization and validation of a reporter cell system for measuring anti-human IFN-β NAb titers, and evaluation data were obtained with samples from 33 patients with multiple sclerosis.

Blood Biomarkers as Outcome Measures in Inflammatory Neurologic Diseases

Multiple sclerosis (MS) is an autoimmune demyelinating disorder of the central nervous system. Only a few biomarkers are available in MS clinical practice, such as cerebrospinal fluid oligoclonal bands and immunoglobulin index, serum anti-aquaporin 4 antibodies, and serum anti-John Cunningham virus antibodies. Thus, there is a significant unmet need for biomarkers to assess prognosis, response to therapy, or potential treatment complications. Here we describe emerging biomarkers that are in development, focusing on those from peripheral blood. There are several limitations in the process of discovery and validation of a good biomarker, such as the pathophysiological complexity of MS and the technical difficulties in globally standardizing methods for sampling, processing, and conserving biological specimens. In spite of these limitations, ongoing international collaborations allow the exploration of many interesting molecules and markers to validate diagnostic, prognostic, and therapeutic-response biomarkers.

The cross-reactivity of binding antibodies with different interferon beta formulations used as disease-modifying drugs in multiple sclerosis patients

Interferon beta (IFNb) preparations are commonly used as first-line therapy in relapsing-remitting multiple sclerosis (RRMS). They are, however, characterized by limited efficacy, partly due to the formation of anti-IFNb antibodies in patients.In this pilot study, we assessed with the ELISA method the presence of the binding antibodies (BAbs) against interferon beta after 2 years of therapy with subcutaneous interferon beta 1a (Rebif) in 49 RRMS patients. Antibody levels were established again within 1 year after treatment withdrawal. We used 3 interferons that are commercially available for MS therapy, namely Avonex (Biogen Idec Limited), Rebif (Merck Serono), and Betaferon (Bayer Pharma AG), as antigens.BAbs reacting with Rebif were found in 24.4% to 55% of patients, depending on the units of their expression. The levels of anti-Rebif antibodies remained high in 8 patients and in 4 patients they dropped significantly. Strong correlations were obtained in all assays (anti-Rebif-anti-Avonex, anti-Rebif-anti-Betaferon, and anti-Betaferon-anti-Avonex) and the existence of cross-reactivity in the formation of antibodies against all the tested formulations of interferon beta was confirmed. The levels of BAbs remain significant in the clinical context, and their assessment is the first choice screening; however, methods of BAbs evaluation can be crucial for further decisions. More studies are needed to confirm our results; specifically it would be of interest to evaluate methods of neutralizing antibodies identification, as we only assessed the binding antibodies. Nevertheless, our results support the concept that in interferon nonresponders, that are positive for binding antibodies, switching the therapy to alternative disease-modifying agent (for example glatiramer acetate, fingolimod, or natalizumab) is justified, whereas the switch to another interferon formulation will probably be of no benefit.

The Use of Oral Disease-Modifying Therapies in Multiple Sclerosis

Three oral disease-modifying drugs-fingolimod, teriflunomide, and dimethyl fumarate (DMF)-are available for treatment of relapsing forms of multiple sclerosis (MS). All three agents were approved in the last decade, primarily on the basis of a moderate to substantial reduction in the occurrence of MS relapses and central nervous system lesion formation detected by MRI. In the trials leading to approval, the first oral disease-modifying drug, fingolimod, reduced the annualized relapse rate (ARR) from 0.40 in placebo-treated patients to 0.18 (FREEDOMS) and from 0.33 in patients treated with interferon β1a intramuscularly to 0.16 (TRANSFORMS). Teriflunomide, approved on the basis of the two placebo-controlled trials TEMSO and TOWER, demonstrated a reduction in the ARR from 0.54 to 0.37 and from 0.50 to 0.32 respectively. The latest oral MS medication, approved in 2014, is DMF, which had been used in a different formulation for treatment of psoriasis for decades. In the 2-year DEFINE study, the proportion of patients with a relapse was reduced to 27 %, compared with 46 % in placebo arm, whereas in the CONFIRM trial, the ARR was reduced from 0.40 (placebo) to 0.22 in the DMF-treated group of patients. In this review, we will elucidate the mechanisms of action of these three medications and compare their efficacy, safety, and tolerability as a practical guideline for their use. We will further discuss effects other than relapse reduction these small molecules may exert, including potential activities within the central nervous system, and briefly summarize emerging data on new oral MS drugs in clinical development.

Incidence, characterization, and clinical impact analysis of peginterferon beta1a immunogenicity in patients with multiple sclerosis in the ADVANCE trial

BACKGROUND

Efficacy of interferon beta in multiple sclerosis (MS) can be dampened in patients who develop neutralizing antidrug antibodies (NAbs). Peginterferon beta1a is an interferon conjugated with a polyethylene glycol (PEG) moiety. Pegylation increases a drug's half life and exposure, and may also reduce immunogenicity.

OBJECTIVE

The objective of this study was to characterize the incidence and impact of immunogenicity to peginterferon beta1a over 2 years in patients with MS.

METHODS

Patients with relapsing-remitting MS (N = 1512) were randomized to subcutaneous peginterferon beta1a 125 μg every 2 or 4 weeks, or placebo, for 1 year; patients in the placebo group were rerandomized to active treatment in year 2. The incidence and titers of binding antibodies (BAbs) and NAbs to interferon and antibodies to PEG (anti-PEG) were assessed in analytically validated assays. The clinical impact of immunogenicity on relapse and magnetic resonance imaging endpoints was evaluated.

RESULTS

Over 2 years, 6%, less than 1%, and 7% of patients developed anti-interferon BAbs, NAbs, and anti-PEG antibodies, respectively. There was no discernible clinically meaningful effect of antibody status on the pharmacodynamic, efficacy, or safety parameters evaluated, although these analyses were limited by the low incidence of treatment-emergent antibodies.

CONCLUSION

The treatment effect of peginterferon beta1a in patients with relapsing-remitting MS is not expected to be attenuated by immunogenicity.

Fatigue and Comorbidities in Multiple Sclerosis

BACKGROUND

Fatigue is commonly reported by people with multiple sclerosis (MS). Comorbidity is also common in MS, but its association with the presence of fatigue or fatigue changes over time is poorly understood.

METHODS

Nine hundred forty-nine people with definite MS were recruited from four Canadian centers. The Fatigue Impact Scale for Daily Use and a validated comorbidity questionnaire were completed at three visits over 2 years. Participants were classified into groups with no fatigue versus any fatigue. Logistic regression was used to determine the relationship between fatigue and each comorbidity at baseline, year 1, year 2, and overall.

RESULTS

The incidence of fatigue during the study was 38.8%. The prevalence of fatigue was greater in those who were older (P = .0004), had a longer time since symptom onset (P = .005), and had greater disability (P < .0001). After adjustment, depression (odds ratio [OR], 2.58; 95% confidence interval [CI], 2.03-3.27), irritable bowel syndrome (OR, 1.71; 95% CI, 1.18-2.48), migraine (OR, 1.69; 95% CI, 1.27-2.27), and anxiety (OR, 1.57; 95% CI, 1.15-2.16) were independently associated with fatigue that persisted during the study. There was also an individual-level effect of depression on worsening fatigue (OR, 1.49; 95% CI, 1.08-2.07).

CONCLUSIONS

Comorbidity is associated with fatigue in MS. Depression is associated with fatigue and with increased risk of worsening fatigue over 2 years. However, other comorbid conditions commonly associated with MS are also associated with persistent fatigue, even after accounting for depression. Further investigation is required to understand the mechanisms by which comorbidities influence fatigue.