A randomized, double-blind, dose-comparison study of weekly interferon beta-1a in relapsing MS

Considerations for Use of Pharmacodynamic Biomarkers to Support Biosimilar Development - (III) A Randomized Trial with Interferon Beta-1a Products

The US Food and Drug Administration (FDA) has taken steps to bring efficiency to the development of biosimilars, including establishing guidance for the use of pharmacokinetic and pharmacodynamic (PD) similarity study data without a comparative clinical study with efficacy end point(s). To better understand the potential role for PD biomarkers in biosimilar development and inform best practices for biomarker selection and analysis, we conducted a randomized, double-blinded, placebo-controlled, single-dose, parallel-arm clinical study in healthy participants. Eighty-four healthy participants (n = 12 per dose arm) received either placebo or one of three doses of either interferon β-1a (7.5-30 μg) or pegylated interferon β-1a (31.25-125 μg) to evaluate the maximum change from baseline and the baseline-adjusted area under the effect curve for the biomarkers neopterin in serum and myxovirus resistance protein 1 in blood. Both PD biomarkers increased following product administration with clear separation from baseline (neopterin: 3.4-fold and 3.9-fold increase for interferon β-1a and pegylated interferon β-1a, respectively; myxovirus resistance protein 1: 19.0-fold and 47.2-fold increase for interferon β-1a and pegylated interferon β-1a, respectively). The dose-response curves support that therapeutic doses were adequately sensitive to detect differences in both PD biomarkers for consideration in a PD similarity study design. Because baseline levels of both biomarkers are low compared with on-treatment values, there was little difference in using PD measures adjusted to baseline compared with the results without baseline adjustment. This study illustrates potential methodologies for evaluating PD biomarkers and an approach to address information gaps when limited information is publicly available for one or more PD biomarkers.

Safety and Monitoring of the Treatment with Disease-Modifying Therapies (DMTs) for Multiple Sclerosis (MS)

BACKGROUND

Disease-Modifying Therapies (DMTs) for Multiple Sclerosis (MS) are widely used given their proven efficacy in the relapsing form of the disease, while recently, Siponimod and Ocrelizumab have been approved for the progressive forms of the disease. Currently, 22 diseasemodifying drugs are approved by the FDA, while in 2012, only nine were present in the market. From March 2019 until August 2020, six new drugs were approved. This rapid development of new DMTs highlighted the need to update our knowledge about their short and long-term safety.

OBJECTIVE

This review summarizes the available safety data for all the Disease-Modifying Therapies for Multiple Sclerosis and presents the monitoring plan before and during the treatment.

METHODS

A literature search was conducted using PUBMED and COCHRANE databases. Key journals and abstracts from major annual meetings of Neurology, references of relevant reviews, and relative articles were also manually searched. We prioritized systematic reviews, large randomized controlled trials (RCTs), prospective cohort studies, and other observational studies. Special attention was paid to guidelines and papers focusing on the safety and monitoring of DMTs.

CONCLUSION

Data for oral (Sphingosine 1-phosphate (S1P) receptor modulators, Fumarates, Teriflunomide, Cladribine), injectables (Interferons, Glatiramer acetate, Ofatumumab), and infusion therapies (Natalizumab, Ocrelizumab, Alemtuzumab) are presented.

Standard Dose Weekly Intramuscular Beta Interferon-1a May Be Inadequate for Some Patients with Multiple Sclerosis: A 19-Year Clinical Experience Using Twice a Week Dosage

INTRODUCTION

Results from several clinical trials suggest there is a dose-response effect for beta interferon-1a (INFβ1a) in multiple sclerosis (MS).

METHODS

Our objective was to confirm these results through a retrospective analysis of patients with MS who had breakthrough disease (BD) on intramuscular (IM) INFβ1a (Avonex®) once per week (QW), who were switched to twice per week (BIW) IM INFβ1a between 1995 and 2015. The primary outcome measure was no further BD for at least 24 months. A secondary outcome measure was decrease in mean percentage of disease activity over time. BD was defined as continued relapses, new T2 or enhanced lesions on magnetic resonance imaging (MRI) of the brain, or worsening of the Expanded Disability Status Scale (EDSS) or the neurological examination.

RESULTS

Among 92 patients on QW IM INFβ1a, 53 patients with BD were switched to BIW IM INFβ1a. Of these 53 patients, 44 had adequate follow-up for at least 2 years. Twenty-three of these had no further BD for 24 months or more (range 24-192 months). Beta interferon neutralizing antibody testing was negative in 19 patients. An intent-to-treat analysis of the uncensored data from 52 switched patients also supported a treatment benefit.

CONCLUSION

For patients with MS having breakthrough disease on QW INFβ1a, switching to more frequently administered INFβ may be an option. Advantages to using IM INFβ1a for this include no skin reactions and a lower incidence of neutralizing antibodies. Further pragmatic, observational, larger-group studies comparing treatment with Avonex® and higher dosed IM INFβ1a, such as the recently FDA-approved IM peginterferon beta-1a, may be indicated.

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.

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.

Targeting Purinergic Signaling and Cell Therapy in Cardiovascular and Neurodegenerative Diseases

Extracellular purines exert several functions in physiological and pathophysiological mechanisms. ATP acts through P2 receptors as a neurotransmitter and neuromodulator and modulates heart contractility, while adenosine participates in neurotransmission, blood pressure, and many other mechanisms. Because of their capability to differentiate into mature cell types, they provide a unique therapeutic strategy for regenerating damaged tissue, such as in cardiovascular and neurodegenerative diseases. Purinergic signaling is pivotal for controlling stem cell differentiation and phenotype determination. Proliferation, differentiation, and apoptosis of stem cells of various origins are regulated by purinergic receptors. In this chapter, we selected neurodegenerative and cardiovascular diseases with clinical trials using cell therapy and purinergic receptor targeting. We discuss these approaches as therapeutic alternatives to neurodegenerative and cardiovascular diseases. For instance, promising results were demonstrated in the utilization of mesenchymal stem cells and bone marrow mononuclear cells in vascular regeneration. Regarding neurodegenerative diseases, in general, P2X7 and A_2A receptors mostly worsen the degenerative state. Stem cell-based therapy, mainly through mesenchymal and hematopoietic stem cells, showed promising results in improving symptoms caused by neurodegeneration. We propose that purinergic receptor activity regulation combined with stem cells could enhance proliferative and differentiation rates as well as cell engraftment.

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.

A review on stem cell therapy for multiple sclerosis: special focus on human embryonic stem cells

Multiple sclerosis (MS), a complex disorder of the central nervous system (CNS), is characterized with axonal loss underlying long-term progressive disability. Currently available therapies for its management are able to slow down the progression but fail to treat it completely. Moreover, these therapies are associated with major CNS and cardiovascular adverse events, and prolonged use of these treatments may cause life-threatening diseases. Recent research has shown that cellular therapies hold a potential for CNS repair and may be able to provide protection from inflammatory damage caused after injury. Human embryonic stem cell (hESC) transplantation is one of the promising cell therapies; hESCs play an important role in remyelination and help in preventing demylenation of the axons. In this study, an overview of the current knowledge about the unique properties of hESC and their comparison with other cell therapies has been presented for the treatment of patients with MS.

A Multiple Treatment Comparison of Eleven Disease-Modifying Drugs Used for Multiple Sclerosis

BACKGROUND

Several disease-modifying drug therapies are available for the treatment of multiple sclerosis (MS). To ensure the most appropriate MS management, we assessed the effectiveness and cost-effectiveness of the disease-modifying medicines used for MS.

METHODS

We conducted a systematic review including 11 disease-modifying drugs used for treatment of adult patients diagnosed with relapsing-remitting MS. We performed a network meta-analysis using both direct and indirect evidence. We examined the endpoints, annual relapse, disability progression, mortality, serious adverse events and withdrawal from the study due to adverse events. Cost-effectiveness was assessed by developing a decision model. The model calculated costs and quality-adjusted life years (QALYs) with different treatment strategies. Uncertainties in the parameter values were explored with a probabilistic sensitivity analysis and several scenario analyses.

RESULTS

Alemtuzumab 12 mg was the most effective against annual relapse (high quality evidence). For disability progression, dimethyl fumarate 240 mg and fingolimod 0.5 mg and 1.25 mg were more effective treatment alternatives (high quality evidence). For withdrawal due to adverse events, the conclusion is unclear due to the low quality of the available evidence. Peg-interferon beta-1a was associated with more adverse events (than the other treatments). None of the examined treatments had an effect on overall mortality compared to placebo. The economic analysis indicated that alemtuzumab was more effective in terms of QALYs and less costly than the other treatment alternatives. Discarding alemtuzumab, three treatment alternatives (interferon beta-1b (Extavia), peg-interferon beta-1a and natalizumab) could be considered cost-effective depending on the willingness-to-pay (WTP) threshold. Assuming a WTP below EUR 111,690 per QALY, interferon beta-1b (Extavia) was approximately 36% likely to be the most cost-effective treatment, followed by peg-interferon beta-1a (approximately 34% likely).

CONCLUSIONS

Our results showed that alemtuzumab can be considered as more effective and less costly than the other treatment alternatives. There is a substantial potential cost saving if more patients start on the more effective and less costly treatment alternatives.

Development of neutralizing antibodies to intramuscular interferon beta-1a (Avonex ®)

The most frequent treatment for relapsing-remitting multiple sclerosis (RRMS) is interferon beta (IFNβ). Development of neutralizing antibodies (NAbs) to IFN therapy is a well-documented phenomenon. Patients who have persistent NAbs of sufficient titer no longer receive clinical benefit from these therapies. In the case of intramuscular (IM) IFNβ-1a (Avonex®), approximately 22% of patients in the pivotal trial (conducted from 1990 to 1994) developed NAbs. However, improvements in the processes for the production of IFNβ-1a-Avonex resulted in a commercial product (first released in 1996) that was significantly less immunogenic; approximately 2% of patients developed NAbs with titers ≥20 neutralizing units (NU)/mL. In a large three-year Phase IV clinical trial using IFNβ-1a-Avonex, it was shown that NAb-positive patients had significantly greater annual relapse rates, greater increases in disability (compared with baseline), and more lesions detected by MRI compared with NAb-negative patients, indicating that the development of NAbs has serious consequences for patients with MS treated with IFNβ. Therefore, maintaining the low immunogenicity of IFNβ-1a-Avonex in the context of improving formulations and delivery options, has been a critical objective for Biogen Idec in the development of this important therapy for patients with MS. Multiple Sclerosis 2007; 13: S14—S20 http://msj.sagepub.com

Interferon beta preparations for the treatment of multiple sclerosis patients differ in neutralizing antibody seroprevalence and immunogenicity

Development of neutralizing antibodies (NAbs) reduces the clinical efficacy of interferon beta (IFNβ) treatment in multiple sclerosis (MS) patients. The aim of this study was to evaluate NAb seroprevalence (frequency of patients with NAbs) and immunogenicity (titer levels) of IFNβ preparations in a clinical setting. We analysed 1115 consecutive MS patients, treated with one of the three available IFNβ preparations, for an average of 40 months (1 – 120 months), for the presence of NAbs with the MxA protein induction assay. Overall, 32% of patients were positive for NAbs with neutralizing titers above 10. The frequency of NAbs, ie, the seroprevalence, was 13% in Avonex-treated patients, 43% for Betaferon, 39% for Rebif22 and 30% for Rebif44. In addition, the potential to induce high titer levels, ie, the immunogenicity, was observed to differ between preparations. Avonex, showing the lowest seroprevalence, also showed low immunogenicity and typically induced low titers. Betaferon, showing the highest seroprevalence when inducing NAbs, induced lower titers compared to Rebif22 and Rebif44. Treatment duration over five years only marginally correlated with decreased seroprevalence and titer levels.

In conclusion, NAbs to IFNβ are common in a clinical setting and the IFNβ preparations differ not only in NAb seroprevalence, but also in immunogenicity. Multiple Sclerosis 2007; 13: 208–214. http://msj.sagepub.com

Transplantation of Human Embryonic Stem Cells in Patients with Multiple Sclerosis and Lyme Disease

Case series

Patient: Male, 42 • Female, 30

Final Diagnosis: Human embryonic stem cells showed good therapeutic potential for treatment of multiple sclerosis with lyme disease

Symptoms: Fatigue • weakness in limbs

Medication: —

Clinical Procedure: Human embryonic stem cells transplantation

Specialty: Transplantology

Effect of interferon-β1α therapy on multiple sclerosis based on gadolinium-enhancing or active T2 magnetic resonance imaging outcomes: a meta-analysis

OBJECTIVES

Interferon-beta1alpha (IFN-β1α) is widely used to modify the course of relapsing-remitting multiple sclerosis. However, many patients have relapses. The purpose of this study was to evaluate magnetic resonance imaging (MRI) as a predictor of IFN-β1α treatment efficacy in patients with MS.

METHODS

PubMed, Embase, and the Cochrane Library were searched to identify eligible studies. Manual searches were also conducted. All eligible trials included MS patients who received IFN-β1α based on gadolinium-enhancing or active T2 MRI lesions for determination of relapse rates.

RESULTS

Of 499 identified studies, we included 10 trials reporting data on 6,037 MS patients. IFN-β1α therapy significantly reduced the risk of relapse (RR: 0.87; 95% confidence intervals (CI): 0.76-0.99; p = 0.032). Furthermore, baseline median T2 lesion volume was found to be related to IFN-β1α therapy and relapse (p = 0.018). Subgroup analysis suggested that IFN-β1α therapy was associated with reduced risk of relapse (RR: 0.82; 95%CI: 0.71-0.94; p = 0.005 versus placebo). However, there was no significant difference in the risk of relapse compared to treatment with low dose IFN-β1α (RR: 0.93; 95%CI: 0.80-1.08; p = 0.337) or glatiramer acetate (RR: 0.93; 95%CI: 0.77-1.14; p = 0.506). Finally, IFN-β1α therapy significantly increased the risk of injection-site disorders, influenza-like syndrome, and alanine transferase elevation.

DISCUSSION

Effects of IFN-β1α therapy are associated with a statistically significant impact on baseline median T2 lesion volume. However, the safety outcomes are significantly worse in patients who receive IFN-β1α therapy.

Persistence of neutralizing antibodies after discontinuation of IFNβ therapy in patients with relapsing-remitting multiple sclerosis

Objective The main objective was to follow serum levels of neutralizing antibodies (NABs) against interferon-beta (IFNβ) after discontinuation of IFNβ therapy.

Background A large proportion of patients treated with recombinant IFNβ for multiple sclerosis (MS) develop therapy-induced NABs. Knowledge of persistence of NABs after discontinuation of therapy is limited. Design/patients: A retrospective follow-up study of patients treated in Denmark for relapsing-remitting (RR) MS with IFNβ for at least 12 months. NAB-positive patients, who discontinued therapy, were followed up with measurements of NABs.

Methods We measured NAB-neutralizing capacity and NAB titres a.m. Kawade using a clinically validated cytopathic effect assay.

Results Thirty-seven patients were included. Mean follow-up time was 22 months. Of the 29 patients with a NAB titre at or above 25 prior to termination of therapy, only three patients reverted to a titre below 25. Of these, two had a titre below 200 and one patient a titre of 600 at the last examination before treatment stop. The longest post-treatment follow-up during which a patient maintained NAB positivity was 59 months.

Conclusion NABs against IFNβ, especially with high titres, tend to persist for a long time after discontinuation of IFNβ therapy. NABs should always be measured before reinstitution of IFNβ treatment in NAB-positive patients.

Interferon β-1a in relapsing multiple sclerosis: four-year extension of the European IFNβ-1a Dose-C omparison Study

Background: Multiple sclerosis (MS) is a chronic disease requiring long-term monitoring of treatment. Objective: To assess the four-year clinical efficacy of intramuscular (IM) IFNb-1a in patients with relapsing MS from the European IFNb-1a Dose-C omparison Study. Methods: Patients who completed 36 months of treatment (Part 1) of the European IFNb-1a Dose-C omparison Study were given the option to continue double-blind treatment with IFNb-1a 30 mcg or 60 mcg IM once weekly (Part 2). Analyses of 48-month data were performed on sustained disability progression, relapses, and neutralizing antibody (NA b) formation. Results: O f 608/802 subjects who completed 36 months of treatment, 493 subjects continued treatment and 446 completed 48 months of treatment and follow-up. IFNb-1a 30 mcg and 60 mcg IM once weekly were equally effective for up to 48 months. There were no significant differences between doses over 48 months on any of the clinical endpoints, including rate of disability progression, cumulative percentage of patients who progressed (48% and 43%, respectively), and annual relapse rates; relapses tended to decrease over 48 months. The incidence of patients who were positive for NAbs at any time during the study was low in both treatment groups. Conclusion: C ompared with 60-mcg IM IFNb-1a once weekly, a dose of 30 mcg IM IFNb-1a once weekly maintains the same clinical efficacy over four years.

Eight-year immunogenicity and safety of interferon beta-1a-Avonex®treatment in patients with multiple sclerosis

An open-label extension study of the phase III trial of intramuscular interferon beta-1a (IFNβ-1a-Avonex) was conducted to evaluate the immunogenicity and safety of IFNβ-1a-Avonex over six years in patients with relapsing multiple sclerosis (MS). Patients who participated in the pivotal phase III study were offered enrolment; entry was also open to patients who had not participated. All patients received IFNβ-1a-Avonex 30 mg intramuscularly once weekly for six years, for a treatment duration of up to eight years in patients who received IFNβ-1a-Avonex in the phase III trial. Serum levels of IFNβ antibodies were measured every six months using a screening enzyme-linked immunosorbent assay (ELISA) followed by an antiviral cytopathic effect assay to detect neutralizing antibodies (NAbs) in serum samples positive on ELISA. The incidence of adverse events and laboratory test results assessed safety. Of 382 total patients, 218 had participated in the phase III study (103 placebo, 115 IFNβ-1a-Avonex) and 164 had not participated; 24 of the 164 were IFNβ-naïve. At baseline, 281 patients were negative for IFNβ antibodies (NAb-). NAbs (titre≥ 20) developed at any time over six years in 5% of these patients. Of 140 patients who had been on IFNβ-1b-Betaseron, 49 were positive for NAbs (NAb+) at baseline; 11 of 115 who had been on IFNβ-1a-Avonex were NAb+ at baseline. Thirty-nine of 49 patients who had been on Betaseron and were NAb+ had titres <100; 36 of these 39 seroconverted to NAb-while on IFNβ-1a-Avonex, with a median time of approximately six months. Ten patients who had been on Betaseron had NAb titres ≥ 100; five remained NAb+ during six years on IFNβ-1a-Avonex and five seroconverted to NAb-, but only after at least two years. Five patients who had been on IFNβ-1a-Avonex during the clinical trial were NAb+ with titres <100 at baseline; four seroconverted to NAb-, with a median time of two to three years. Six patients who had been on IFNβ-1a-Avonex had NAb titres ≥100; five of these remained NAb+ at six years. No patient with a NAb titre >1000 seroconverted to NAb-, whether initially treated with IFNβ-1a-Avonex or -Betaseron. Adverse events were similar to those observed in the pivotal phase III trial. Results from this trial indicated that IFNβ-1a-Avonex was associated with a low incidence of NAbs and was well tolerated for up to eight years. Further, the results indicate that persistence of NAbs is dependent on titre and IFNβ product.

Differing immunogenic potentials of interferon beta preparations in multiple sclerosis patients

Interferon beta (IFNβ) is a first-line therapy for multiple sclerosis (MS). However, some patients experience a decline in efficacy with continued therapy due to the development of anti-IFNβ neutralizing antibodies (NAb). We investigated the frequency of NAb cross-sectionally in 846 MS patients who were receiving IFNβ-1b, IFNβ-1a im, or IFNβ-1a sc. The frequency of NAb in patients receiving IFNβ-1a im was lower (5%) than in patients treated with any other form of IFNβ (22-35%) (P < 0.0001). Binding antibodies (BAb) were measured in 808 patients. The frequency differed significantly between treatment groups, ranging from 45% (IFNβ-1a im) to 88% (IFNβ-1b). The proportion of NAb-positive patients within the BAb-positive group differed significantly among treatment groups, ranging between 12% (IFNβ-1a im) and 51% (IFNβ-1a sc). The median NAb titer from all IFNβ-1a-treated patients was higher than from IFNβ-1b-treated patients (446 versus 171 NU/mL, P = 0.04). Among NAb-positive patients, the frequency of NAb titers > 100 NU/mL was 71% for IFNβ-1a compared with 58% for IFNβ-1b (P = 0.04). Except for conflicting data regarding IFNβ-1a sc, the results are generally consistent with the literature and together with the differing proportion of NAb-positive patients within the BAb-positive group, provide further insight into the immunogeni-city of the IFNβ preparations.

Interferon-beta: the neutralizing antibody (NAb) titre predicts reversion to NAb negativity

Background: It has been reported that in some patients with MS who develop neutralizing antibodies (NAbs) against interferon beta (IFNb), antibody levels can initially increase and then decrease thereafter even when treatment is continued. Objective: To determine whether NAb titre correlates with time to reversion to NAb negativity in patients with multiple sclerosis (MS). Methods: Twenty-eight patients with MS who were NAb-positive during treatment with one of the currently available IFNbs were included in this retrospective study. NAb titres were determined by the myxovirus resistance protein A induction assay. Patients were considered NAb-positive if they had at least two consecutive samples with titres of]/20 neutralizing units (NU). Reversion to NAb-negative status was defined as two consecutive negative samples (NAb titre of B/20 NU) after NAb positivity. Results: When measured two years after treatment initiation, a NAb titre of B/75 NU had a 91.7% sensitivity and a 87.5% specificity for reversion to NAb negativity in the following two years (after a total of four years of treatment). In addition, somewhat surprisingly, patients whose serum converted to NAb-negative generally developed peak NAb titres earlier than patients who remained NAb-positive (mean time of first detection was 21 versus 38 months, respectively). Conclusion: The NAb titre might support treatment decisions in patients with MS whose test results are positive for NAbs.

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.

Pharmacokinetic considerations in the treatment of multiple sclerosis with interferon-β

INTRODUCTION

Interferon-β (IFNβ) is well established as a disease-modifying treatment for patients with multiple sclerosis. Several preparations of the biopharmaceutical are available differing in protein structure, formulation, dose as well as frequency and route of administration. Recently, a pegylated form of IFNβ has been marketed.

AREAS COVERED

Following a PubMed database search, we provide an overview of what is presently known about the pharmacokinetics (PK) of IFNβ including its absorption, distribution, metabolism and elimination. Also, we discuss the association with clinically relevant issues such as treatment efficacy, adverse events and anti-drug antibodies.

EXPERT OPINION

IFNβ has a bioavailability of ∼ 30% after subcutaneous or intramuscular administration, shows peak serum concentrations within several hours, has a half-life of < 1 day and is eliminated by a renal and hepatic pathway. PK parameters do not substantially differ between the types of IFNβ and routes of administration; only pegylation of IFNβ results in substantially increased and prolonged PK. Although no clinical dose-effect relationship could be established, there is an association of IFNβ dose with magnetic resonance imaging outcome parameters. Furthermore, there is an association of IFNβ serum levels with the occurrence of adverse events and anti-drug antibodies.

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.

Interferon-β1bin multiple sclerosis

In 1993, interferon (IFN)-beta(1b) for subcutaneous injection became the first US FDA-approved immunomodulatory treatment for multiple sclerosis, a chronic inflammatory disease of the CNS. In this review of IFN-beta(1b), we first present a short introduction to multiple sclerosis and currently available therapeutics. We then summarize current knowledge about the biochemical structure of IFN-beta(1b), as well as pharmacokinetics and pharmacodynamics, including data on putative mechanisms underlying therapeutic as well as adverse effects. Furthermore, a critical review of ongoing and recently published clinical trials investigating IFN-beta(1b) in multiple sclerosis will be provided. Main topics are: trials investigating IFN-beta(1b) after a first clinical event, at higher dosages or in comparison to once-weekly subcutaneous IFN-beta(1a) injections, 16 years of long-term follow-up, IFN-beta(1b) in Japanese patients, the role of neutralizing antibodies, biomarkers for the prediction of therapy response, IFN-beta(1b) and pregnancy, and IFN-beta(1b) treatment of children with multiple sclerosis. Finally, we discuss how novel drugs, especially monoclonal antibodies and orally administered immunosuppressants, might soon challenge the position of this well-established agent on the multiple sclerosis therapeutics market.

Disease-modifying agents in multiple sclerosis

Over the past two decades, major advances have been made in the development of disease-modifying agents (DMAs) for multiple sclerosis (MS), and nine agents are now licensed for use in the treatment of MS in the United States. Clinical trials have demonstrated that a number of investigational agents have beneficial effects on clinical and radiographic measures of disease activity, thus the repertoire of available DMAs in MS will likely continue to expand moving forward. Although many of the first-line DMAs have the benefits of established long-term safety and tolerability, in some patients, treatment with one of the more potent novel agents may be appropriate. However, the use of novel agents must be approached with caution, since short-term clinical trials give little information on the long-term efficacy and safety of novel DMAs in MS patients. This chapter will consider the efficacy and safety of both established and investigational agents for the treatment of MS.

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.

Multiple Sclerosis Outcome Assessments Consortium: Genesis and initial project plan

The need for improved clinical outcome measures in multiple sclerosis trials has been recognized for two decades, but only recently has the Food and Drug Administration (FDA) created a pathway for qualification of new clinician-reported outcome (ClinRO) assessments. Additionally, drug development in multiple sclerosis (MS) has been extraordinarily active, with numerous disease-modifying drugs now on the market. This shifting therapeutic landscape, along with the unmet need for drugs to treat the progressive forms of MS and the changing expectations of clinicians, patients, and payers, have led to the call for more sensitive and meaningful disability progression measures. In response to these drivers, the Multiple Sclerosis Outcome Assessments Consortium (MSOAC) was launched. A public-private partnership, MSOAC aims to accelerate the development of new therapies for MS by generating new tools for measuring outcomes in clinical trials. At the first annual MSOAC/FDA meeting, a regulatory path was outlined for qualifying a new tool for assessing efficacy in registration trials of MS. The European Medicines Agency (EMA) and FDA will provide parallel consultation and review. The consensus approach with engagement by all of the stakeholders, prominently including patients with MS, should also increase acceptance of the measure by clinicians and patients.

Immunomodulators and immunosuppressants for multiple sclerosis: a network meta-analysis

BACKGROUND

Different therapeutic strategies are available for treatment of multiple sclerosis (MS) including immunosuppressants, immunomodulators, and monoclonal antibodies. Their relative effectiveness in the prevention of relapse or disability progression is unclear due to the limited number of direct comparison trials. A summary of the results, including both direct and indirect comparisons of treatment effects, may help to clarify the above uncertainty.

OBJECTIVES

To estimate the relative efficacy and acceptability of interferon ß-1b (IFNß-1b) (Betaseron), interferon ß-1a (IFNß-1a) (Rebif and Avonex), glatiramer acetate, natalizumab, mitoxantrone, methotrexate, cyclophosphamide, azathioprine, intravenous immunoglobulins, and long-term corticosteroids versus placebo or another active agent in participants with MS and to provide a ranking of the treatments according to their effectiveness and risk-benefit balance.

SEARCH METHODS

We searched the Cochrane Database of Systematic Reviews, the Cochrane MS Group Trials Register, and the Food and Drug Administration (FDA) reports. The most recent search was run in February 2012.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that studied one of the 11 treatments for use in adults with MS and that reported our pre-specified efficacy outcomes were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Identifying search results and data extraction were performed independently by two authors. Data synthesis was performed by pairwise meta-analysis and network meta-analysis that was performed within a Bayesian framework. The body of evidence for outcomes within the pairwise meta-analysis was assessed according to GRADE, as very low, low, moderate, or high quality.

MAIN RESULTS

Forty-four trials were included in this review, in which 17,401 participants had been randomised. Twenty-three trials included relapsing-remitting MS (RRMS) (9096 participants, 52%), 18 trials included progressive MS (7726, 44%), and three trials included both RRMS and progressive MS (579, 3%). The majority of the included trials were short-term studies, with the median duration being 24 months. The results originated mostly from 33 trials on IFNß, glatiramer acetate, and natalizumab that overall contributed outcome data for 9881 participants (66%).From the pairwise meta-analysis, there was high quality evidence that natalizumab and IFNß-1a (Rebif) were effective against recurrence of relapses in RRMS during the first 24 months of treatment compared to placebo (odds ratio (OR) 0.32, 95% confidence interval (CI) 0.24 to 0.43; OR 0.45, 95% CI 0.28 to 0.71, respectively); they were more effective than IFNß-1a (Avonex) (OR 0.28, 95% CI 0.22 to 0.36; OR 0.19, 95% CI 0.06 to 0.60, respectively). IFNß-1b (Betaseron) and mitoxantrone probably decreased the odds of the participants with RRMS having clinical relapses compared to placebo (OR 0.55, 95% CI 0.31 to 0.99; OR 0.15, 95% CI 0.04 to 0.54, respectively) but the quality of evidence for these treatments was graded as moderate. From the network meta-analysis, the most effective drug appeared to be natalizumab (median OR versus placebo 0.29, 95% credible intervals (CrI) 0.17 to 0.51), followed by IFNß-1a (Rebif) (median OR versus placebo 0.44, 95% CrI 0.24 to 0.70), mitoxantrone (median OR versus placebo 0.43, 95% CrI 0.20 to 0.87), glatiramer acetate (median OR versus placebo 0.48, 95% CrI 0.38 to 0.75), IFNß-1b (Betaseron) (median OR versus placebo 0.48, 95% CrI 0.29 to 0.78). However, our confidence was moderate for direct comparison of mitoxantrone and IFNB-1b vs placebo and very low for direct comparison of glatiramer vs placebo. The relapse outcome for RRMS at three years' follow-up was not reported by any of the included trials.Disability progression was based on surrogate markers in the majority of included studies and was unavailable for RRMS beyond two to three years. The pairwise meta-analysis suggested, with moderate quality evidence, that natalizumab and IFNß-1a (Rebif) probably decreased the odds of the participants with RRMS having disability progression at two years' follow-up, with an absolute reduction of 14% and 10%, respectively, compared to placebo. Natalizumab and IFNß-1b (Betaseron) were significantly more effective (OR 0.62, 95% CI 0.49 to 0.78; OR 0.35, 95% CI 0.17 to 0.70, respectively) than IFNß-1a (Avonex) in reducing the number of the participants with RRMS who had progression at two years' follow-up, and confidence in this result was graded as moderate. From the network meta-analyses, mitoxantrone appeared to be the most effective agent in decreasing the odds of the participants with RRMS having progression at two years' follow-up, but our confidence was very low for direct comparison of mitoxantrone vs placebo. Both pairwise and network meta-analysis revealed that none of the individual agents included in this review were effective in preventing disability progression over two or three years in patients with progressive MS.There was not a dose-effect relationship for any of the included treatments with the exception of mitoxantrone.

AUTHORS' CONCLUSIONS

Our review should provide some guidance to clinicians and patients. On the basis of high quality evidence, natalizumab and IFNß-1a (Rebif) are superior to all other treatments for preventing clinical relapses in RRMS in the short-term (24 months) compared to placebo. Moderate quality evidence supports a protective effect of natalizumab and IFNß-1a (Rebif) against disability progression in RRMS in the short-term compared to placebo. These treatments are associated with long-term serious adverse events and their benefit-risk balance might be unfavourable. IFNß-1b (Betaseron) and mitoxantrone probably decreased the odds of the participants with RRMS having relapses, compared with placebo (moderate quality of evidence). The benefit-risk balance with azathioprine is uncertain, however this agent might be effective in decreasing the odds of the participants with RRMS having relapses and disability progression over 24 to 36 months, compared with placebo. The lack of convincing efficacy data shows that IFNß-1a (Avonex), intravenous immunoglobulins, cyclophosphamide and long-term steroids have an unfavourable benefit-risk balance in RRMS. None of the included treatments are effective in decreasing disability progression in patients with progressive MS. It is important to consider that the clinical effects of all these treatments beyond two years are uncertain, a relevant point for a disease of 30 to 40 years duration. Direct head-to-head comparison(s) between natalizumab and IFNß-1a (Rebif) or between azathioprine and IFNß-1a (Rebif) should be top priority on the research agenda and follow-up of the trial cohorts should be mandatory.

MRI lesions as a surrogate for relapses in multiple sclerosis: a meta-analysis of randomised trials

BACKGROUND

A meta-analysis of randomised trials in relapsing-remitting multiple sclerosis published in 2009 showed a quantitative relation between the treatment effects detected on MRI lesions and clinical relapses. We aimed to validate that relation using data from a large and independent set of clinical trials in multiple sclerosis.

METHODS

We searched Medline for clinical trials that assessed disease-modifying drugs for relapsing-remitting multiple sclerosis published from Sept 1, 2008, to Oct 31, 2012. We extracted data for the treatment effects on MRI lesions and on relapses from each trial, and the correlation of log transformed relative measures of these treatment effects was assessed with a weighted linear regression analysis. The R(2) value was estimated to quantify the strength of the correlation, and we used an interaction test to test for a difference in slope from the previously estimated equation. We also ran several sensitivity analyses.

FINDINGS

We identified 31 eligible trials, which provided data for 18 901 patients with relapsing-remitting multiple sclerosis. The regression equation derived using data from these studies showed a relation between the concurrent treatment effects on MRI lesions and relapses (slope=0·52; R(2)=0·71), much the same as was previously estimated (pinteraction=0·45). Analysis of trials that tested the same drugs in phase 2 and phase 3 studies showed that the effects on MRI lesions over short follow-up periods (6-9 months) can also predict the effects on relapses over longer follow-up periods (12-24 months), with reported effects on relapses that were within the 95% prediction intervals in eight of nine trials.

INTERPRETATION

Our findings indicate that the effect of a treatment on relapses can be accurately predicted by the effect of that therapy on MRI lesions, implying that the use of MRI markers as primary endpoints in future clinical trials of treatments for multiple sclerosis can be considered, in specific situations, such as in trials testing generics or biosimilars of drugs with a well known mechanism of action or in paediatric trials testing drugs already approved for adults.

FUNDING

None.

Cost-effectiveness of disease-modifying therapies in multiple sclerosis

Multiple sclerosis (MS) is a leading cause of disability among young adults and has a significant economic impact on society. Although MS is not currently a curable disease, costly treatments known as disease-modifying therapies (DMTs) are available to reduce the disease impact in certain types of MS. In the current economic downturn, cost-effectiveness analysis (CEA) of therapies in MS has become an important part of the decision-making process in order to use resources efficiently in the face of the rapidly escalating costs of MS. While some studies have reported costs of DMTs at the level of cost-effectiveness thresholds, some have estimated their costs beyond the tolerance level of health care systems. On the basis of the current literature and given the difficulties in accurately assessing cost-effectiveness in diseases like MS, it is challenging to determine whether DMTs are cost-effective. Further population-based studies are required regarding the cost-effectiveness of therapies in MS.

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.

Clinical testing for neutralizing antibodies to interferon-β in multiple sclerosis

Biopharmaceuticals are drugs which are based on naturally occurring proteins (antibodies, receptors, cytokines, enzymes, toxins), nucleic acids (DNA, RNA) or attenuated microorganisms. Immunogenicity of these agents has been commonly described and refers to a specific antidrug antibody response. Such immunogenicity represents a major factor impairing the efficacy of biopharmaceuticals due to biopharmaceutical neutralization. Indeed, clinical experience has shown that induction of antidrug antibodies is associated with a loss of response to biopharmaceuticals and also with hypersensitivity reactions. The first disease-specific agent licensed to treat multiple sclerosis (MS) was interferon-β (IFNβ). In its various preparations, it remains the most commonly used first-line agent. The occurrence of antidrug antibodies has been extensively researched in MS, particularly in relation to IFNβ. However, much controversy remains regarding the significance of these antibodies and incorporation of testing into clinical practice. Between 2% and 45% of people treated with IFNβ will develop neutralizing antibodies, and this is dependent on the specific drug and dosing regimen. The aim of this review is to discuss the use of IFNβ in MS, the biological and clinical relevance of anti-IFNβ antibodies (binding and neutralizing antibodies), the incorporation of testing in clinical practice and ongoing research in the field.

Alemtuzumab versus interferon beta 1a as first-line treatment for patients with relapsing-remitting multiple sclerosis: a randomised controlled phase 3 trial

BACKGROUND

The anti-CD52 monoclonal antibody alemtuzumab reduced disease activity in a phase 2 trial of previously untreated patients with relapsing-remitting multiple sclerosis. We aimed to assess efficacy and safety of first-line alemtuzumab compared with interferon beta 1a in a phase 3 trial.

METHODS

In our 2 year, rater-masked, randomised controlled phase 3 trial, we enrolled adults aged 18-50 years with previously untreated relapsing-remitting multiple sclerosis. Eligible participants were randomly allocated in a 2:1 ratio by an interactive voice response system, stratified by site, to receive intravenous alemtuzumab 12 mg per day or subcutaneous interferon beta 1a 44 μg. Interferon beta 1a was given three-times per week and alemtuzumab was given once per day for 5 days at baseline and once per day for 3 days at 12 months. Coprimary endpoints were relapse rate and time to 6 month sustained accumulation of disability in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT00530348.

FINDINGS

187 (96%) of 195 patients randomly allocated interferon beta 1a and 376 (97%) of 386 patients randomly allocated alemtuzumab were included in the primary analyses. 75 (40%) patients in the interferon beta 1a group relapsed (122 events) compared with 82 (22%) patients in the alemtuzumab group (119 events; rate ratio 0·45 [95% CI 0·32-0·63]; p<0.0001), corresponding to a 54·9% improvement with alemtuzumab. Based on Kaplan-Meier estimates, 59% of patients in the interferon beta 1a group were relapse-free at 2 years compared with 78% of patients in the alemtuzumab group (p<0·0001). 20 (11%) of patients in the interferon beta 1a group had sustained accumulation of disability compared with 30 (8%) in the alemtuzumab group (hazard ratio 0·70 [95% CI 0·40-1·23]; p=0·22). 338 (90%) of patients in the alemtuzumab group had infusion-associated reactions; 12 (3%) of which were regarded as serious. Infections, predominantly of mild or moderate severity, occurred in 253 (67%) patients treated with alemtuzumab versus 85 (45%) patients treated with interferon beta 1a. 62 (16%) patients treated with alemtuzumab had herpes infections (predominantly cutaneous) compared with three (2%) patients treated with interferon beta 1a. By 24 months, 68 (18%) patients in the alemtuzumab group had thyroid-associated adverse events compared with 12 (6%) in the interferon beta 1a group, and three (1%) had immune thrombocytopenia compared with none in the interferon beta 1a group. Two patients in the alemtuzumab group developed thyroid papillary carcinoma.

INTERPRETATION

Alemtuzumab's consistent safety profile and benefit in terms of reductions of relapse support its use for patients with previously untreated relapsing-remitting multiple sclerosis; however, benefit in terms of disability endpoints noted in previous trials was not observed here.

FUNDING

Genzyme (Sanofi) and Bayer Schering Pharma.

Serum IL-17F does not predict poor response to IM IFNβ-1a in relapsing-remitting MS

OBJECTIVE

There is a significant unmet need for serum biomarkers in relapsing-remitting multiple sclerosis (RRMS) that are predictive of therapeutic response to disease-modifying therapies. Following a recent Stanford study which reported that pretreatment levels of serum interleukin (IL)-17F could predict poor response to interferon-β (IFNβ) therapy, we sought to validate the finding using samples from a large clinical trial.

METHODS

The validation cohort included 54 good responders (GR) and 64 poor responders (PR) selected from 762 subjects with RRMS from the IM IFNβ-1a dose comparison study (Avonex study C94-805). Subjects were classified as GR and PR based on the number of relapses, Expanded Disability Status Scale score, and new and enlarging T2 lesions on MRI. Serum samples were assayed for IL-17F using a multiplexed Luminex assay and for IL-17F/F using an ELISA. Replicate aliquots from the Stanford study were also assayed to assure reproducibility of methods.

RESULTS

Median pretreatment and post-treatment serum IL-17F levels were not statistically significantly different between GR and PR, and serum IL-7/IL-17F ratios were also not predictive of response status. Replicate aliquots from the Stanford study showed good correlation to their original cohort (r = 0.77).

CONCLUSIONS

We were unable to validate the finding that serum IL-17F is a predictor of PR in a large independent cohort of subjects with RRMS. Differences in patient populations and methodology might explain the failure to validate the results from the Stanford study.

Intramuscular interferon beta-1a is effective in Japanese patients with relapsing-remitting multiple sclerosis: a pre-treatment versus treatment comparison study of gadolinium-enhanced MRI brain lesions

BACKGROUND AND OBJECTIVE

Interferon beta (IFNβ) is standard therapy for multiple sclerosis (MS). The efficacy of intramuscular (IM) IFNβ-1a (AVONEX(®)) was assessed in 25 Japanese patients with relapsing-remitting MS (RRMS).

METHODS

Patients with RRMS not previously treated with IFNβ or other disease-modifying therapies were included in this 36-week study. The primary outcome was the average total number of gadolinium-enhanced lesions detected on four brain MRI scans during the last 12 weeks of 24 weeks' treatment with IM IFNβ-1a 30 μg once weekly compared with the number during the 12-week pre-treatment period. Lesions were counted by blinded investigators.

RESULTS

IM IFNβ-1a significantly decreased the median number of gadolinium-enhanced lesions from 2.5 to 0.3 (p < 0.0001) compared with pre-treatment values. The median number of new gadolinium-enhanced lesions also decreased significantly from 2.0 to 0.3 (p = 0.0002). Serum neopterin was induced in a manner similar to that observed previously in a Caucasian RRMS population. No new adverse events occurred during the study.

CONCLUSION

This first study of IM IFNβ-1a in Japanese patients with RRMS demonstrated a level of efficacy similar to that reported in Caucasian patients based on an assessment of pre-treatment and post-treatment gadolinium-enhanced lesions.

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.

Adverse events of interferon beta-1a: a prospective multi-centre international ICH-GCP-based CRO-supported external validation study in daily practice

Background

Due to methodological shortcomings the available post-registration data on the adverse events (AEs) occurring in interferon beta-1a (INFb-1a)-treated patients fail to adequately validate phase III data and only partially inform on safety in daily practice. We assessed AEs in relapsing remitting multiple sclerosis (RRMS) patients treated with intramuscular (IM) INFb-1a in daily practice using data quality assurance measures similar to those in phase III trials.

Methods

A prospective, International Conference on Harmonization (ICH) - Good Clinical Practice (GCP)-based, clinical research organization (CRO)-supported study in 36 practices in the Netherlands, Belgium, the United Kingdom and Luxembourg. During 24 months after start of IM INFb-1a treatment 275 RRMS patients were assessed for AEs' severity (mild, moderate, severe) and relationship to treatment (not, unlikely, likely, definite). Data were compared with those reported in the pivotal phase III trial.

Findings

75.3% of the patients experienced one or more AEs that were likely or definitely related to INFb-1a. Of all AEs 40.5% were likely or definitely treatment-related; 68.5% of these were mild, and 3% severe. 6.6% of the patients discontinued treatment because of an AE. Compared to the pivotal phase III trial, we found statistically significantly lower incidences for most of the common AEs: headache, muscle ache, fatigue, fever, chills, nausea. One patient died following two cerebral vascular events in study month 22, both AEs were assessed as not related to INFb-1a.

Conclusion

Three out of four RRMS patients treated with IM INFb-1a in daily practice experience treatment-related AEs, most of these being mild. Our data externally validate the favorable phase III safety profile of IM INFb-1a and suggest that the real-life incidence of treatment-related AEs is less than reported in the pivotal phase III trial. Larger studies are needed to detect rare, potentially hazardous AEs of IM INFb-1a.

Persistency of neutralizing antibodies depends on titer and interferon-beta preparation

Background: Neutralizing antibodies (NAbs) affect the efficacy of interferon-beta (IFNβ) treatment in multiple sclerosis (MS) patients, particularly if NAbs persist. Persistency depends on NAb titers, which differ between IFNβ preparations.

Objective: This study evaluated IFNβ preparation-specific NAb cut-off titers during early treatment for prediction of NAb persistency.

Methods: Patients who had at least one NAb test between 12 and 30 months (baseline) as well as after more than 48 months (follow-up) on IFNβ treatment were included in this longitudinal study.

Results: At baseline 1064 patients had a NAb test. Of those, 203 had a follow-up test. In the follow-up group 23.2% of patients were NAb positive during baseline. NAb frequency significantly decreased by 40.7% in the IFNβ-1a and by 60% in the IFNβ-1b group at follow-up after a mean time of 75.4 months on treatment, and median NAb titers decreased significantly in both groups. During baseline, NAb titers of >258 neutralizing units (NU) had a sensitivity of 81.3% and a specificity of 90.9% in the IFNβ-1a group, whereas titers of >460 NU had a sensitivity of 100% and a specificity of 91.7% in the IFNβ-1b group to predict persistency at follow-up. When these cut-off titers are applied, 10.2% of all treated patients developed persistent NAbs.

Conclusion: IFNβ preparation-specific NAb cut-off titers for prediction of NAb persistency, which may be useful in individual treatment decision making, are provided.

Neutralizing antibodies to interferon beta-1b multiple sclerosis: a clinico-radiographic paradox in the BEYOND trial

BACKGROUND

The frequency and impact of neutralizing antibodies (NAbs) to interferon beta-1b (IFNβ-1b) on clinical and radiographic outcomes is controversial.

OBJECTIVE

To assess NAb impact in the BEYOND study.

METHODS

2244 patients were randomized (2:2:1) to receive IFNβ-1b, either 250 or 500 µg, or glatiramer acetate, 20 mg, and observed for 2-3.5 years. NAb titers were determined every 6 months. A titer ≥20 NU/ml was considered NAb positive. Efficacy was compared between NAb-positive and NAb-negative patients, using comprehensive statistical analyses, taking into account the delayed appearance of NAbs, the time-dependent changes in the relapse rate, spontaneous reversions to NAb-negative status, NAb-titer level, and also adjusting for baseline factors.

RESULTS

In the IFNβ-1b 250 µg group, NAb-positive titers were detected (≥ once) in 319 patients (37.0%); of these, 112 (35.1%) reverted to NAb-negative status. In the IFNβ-1b 500 µg group, 340 patients (40.7%) became NAb-positive and 119 (35.0%) reverted to NAb-negative status. In both IFNβ groups, especially the 250 µg arm, NAb-positive status was not associated with a convincing impact on any clinical outcome measure by any statistical analysis. By contrast, in both IFNβ groups, NAbs were associated with a very consistent deleterious impact on most MRI outcomes.

CONCLUSION

There was a notable dissociation between the impact of NAbs on MRI and clinical outcomes. On MRI measures, the impact was consistent and convincing, whereas on clinical measures a negative impact of NAbs was not found. The basis for this clinico-radiographic paradox is unknown but it suggests that the relationship between NAbs and the therapeutic effects of IFNβ-1b is complex.

The interferon beta therapies for treatment of relapsing-remitting multiple sclerosis: are they equally efficacious? A comparative review of open-label studies evaluating the efficacy, safety, or dosing of different interferon beta formulations alone or in combination

Interferon beta preparations are the most widely used initial therapies prescribed for patients with relapsing-remitting multiple sclerosis. Phase III studies have demonstrated comparable efficacy on clinical measures of disease activity, variable benefits on radiological measures, and good overall tolerability. Subsequent clinical studies have attempted to compare directly the three available interferon beta preparations, reporting both safety and efficacy data. We review the literature on studies evaluating interferon beta therapy for patients with relapsing-remitting multiple sclerosis, discuss reasons for discrepant findings, and assess the utility of interferon beta-based combination regimens as the focus of future studies in the increasingly complex multiple sclerosis therapy landscape.

Weekly IM interferon beta-1a in multiple sclerosis patients over 50 years of age

BACKGROUND

Efficacy and safety data have not previously been compiled for intramuscular interferon beta-1a (IM IFNβ-1a) in patients with multiple sclerosis (MS) ≥ 50 years of age. We investigated the efficacy and safety of IM IFNβ-1a in patients segregated by 50 and 40 years of age in separate meta-analyses.

METHODS

The MS Clinical Research Group Study, the Controlled High-Risk Subjects AVONEX(®) (IM IFNβ-1a) MS Prevention Study, the IFNβ-1a European Dose-Comparison Study, and a multicenter, open-label antigenicity and safety study of human serum albumin-free IM IFNβ-1a were analyzed.

RESULTS

Overall, 906 patients (68 aged ≥ 50 years and 838 aged <50 years, or 323 aged ≥ 40 years and 583 aged <40 years) received IM IFNβ-1a for ≥ 24 months. At baseline, patients ≥ 50 years had significantly higher Expanded Disability Status Scale scores than patients <50 years (3.4 vs. 2.8; P < 0.001), but fewer relapses in the three preceding years (2.6 vs. 3.4; P < 0.001); patients ≥ 40 years and <40 years exhibited similar differences. After 2 years of treatment, there were no significant differences in annualized relapse rate, sustained disability progression, time to sustained disability progression, or number of MRI-identified gadolinium-enhanced lesions between age groups in either analysis. The cumulative probability of relapse was significantly lower in patients ≥ 40 years versus patients <40 years (0.601 vs. 0.702; P < 0.001). Adverse event incidence did not differ significantly between age groups in either analysis.

CONCLUSIONS

IM IFNβ-1a is effective and well tolerated in patients with MS ≥ 40 and ≥ 50 years as well as younger patients.

On the role of aggregates in the immunogenicity of recombinant human interferon beta in patients with multiple sclerosis

Like many other therapeutic proteins, recombinant human interferon beta (rhIFN-&#x03B2;) elicits undesirable immune responses. rhIFN-&#x03B2;-treated multiple sclerosis patients may form binding antibodies and neutralizing antibodies (NAbs), with the latter being responsible for inhibition of the therapeutic effect of the protein. The incidence of binding antibodies and NAbs against rhIFN-&#x03B2; as well as the titer and persistence of NAbs differ among the marketed products. The proportion of patients forming antibodies against rhIFN-&#x03B2;-1b is higher than that against rhIFN-&#x03B2;-1a, which is likely explained by the differences in protein structure and aggregation behavior between the 2 types of rhIFN-&#x03B2;. Here, we summarize the different factors influencing the immunogenicity of rhIFN-&#x03B2; in patients with multiple sclerosis and discuss the role played by rhIFN-&#x03B2; aggregates.