Immunogenicity and tolerability of an investigational formulation of interferon-beta1a: 24- and 48-week interim analyses of a 2-year, single-arm, historically controlled, phase IIIb study in adults with multiple sclerosis

Dietary Inflammatory Index score and its association with body mass index, body fat percentage, body fat mass, and lipid profile in patients with multiple sclerosis

Background/aim

Multiple sclerosis (MS) may cause modifications in body composition, particularly for body fat associated with obesity and some biochemical parameters such as lipid profiles. We investigated whether there is a link between the inflammatory contents of diets and body composition and lipid profiles in patients with MS.

Materials and methods

This was a cross-sectional study that included 85 MS patients. The study data of the patients were collected in the Neurology Clinic of Ondokuz Mayıs University's Health Practice and Research Center. The data included demographic characteristics; anthropometric measurements such as body weight, height, body mass index, waist circumference, hip circumference, body fat mass, body fat-free mass, and waist-hip ratio; and biochemical parameters such as high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol, triglyceride, and total cholesterol.

Results

The body fat percentages of the patients were higher among those with proinflammatory diets (p < 0.05). Body fat percentage had a positive and very weak correlation with the Dietary Inflammatory Index (DII) score (rho = 0.206 and rho = 0.217, respectively; p < 0.05). HDL-c levels were higher in the group with high DII scores and there was a positive and weak correlation between HDL-c and DII scores (rho = 0.307, p < 0.05). Crude and adjusted linear regression models showed that the effect of HDL-c on DII scores was significant (p < 0.05).

Conclusion

We showed that DII scores, associated with the inflammatory potential of the diet and proinflammatory diets, may be associated with adiposity in MS patients and can be used from a clinical point of view for assessment.

Renal diseases secondary to interferon-β treatment: a multicentre clinico-pathological study and systematic literature review

Background

The spectrum of interferon-β (IFN-β)-associated nephropathy remains poorly described and the potential features of this uncommon association remain to be determined.

Methods

In this study we retrospectively analysed the clinical, laboratory, histological and therapeutic data of patients with biopsy-proven renal disease in a context of IFN-β treatment administered for at least 6 months.

Results

Eighteen patients (13 women, median age 48 years) with biopsy-proven renal disease occurring during IFN-β therapy were included. The median exposure to IFN-β (14 patients were treated with IFN-β1a and 4 patients with IFN-β1b) was 67 months (range 23–165 months). The clinical presentation consists in hypertension (HT; 83%), malignant HT (44%), proteinuria (protU) >1 g/g (94%), reduced renal function (78%), biological hallmark suggesting thrombotic microangiopathy (TMA; 61%), oedematous syndrome (17%) or nephritic syndrome (11%). The pathological findings included typical features of isolated TMAs in 11 cases, isolated focal segmental glomerulosclerosis (FSGS) lesions in 2 cases and 5 cases with concomitant TMA and FSGS lesions. An exploration of the alternative complement pathway performed in 10 cases (63%) did not identify mutations in genes that regulate the complement system. The statistical analysis highlighted that the occurrence of IFN-β-associated TMA was significantly associated with Rebif, with a weekly dose >50 µg and with multiple weekly injections. In all cases, IFN-β therapy was discontinued. Patients with TMA lesions received other therapies, including corticosteroids (44%), eculizumab (13%) and plasma exchanges (25%). At the end of a 36-month median follow-up, persistent HT and persistent protU were observed in 61% and 22% of patients, respectively. Estimated glomerular filtration rate <60 mL/min/1.73 m² was present in 61% of patients.

Conclusions

IFN-β-associated nephropathy must be sought in the case of HT and/or protU onset during treatment. When TMA and/or FSGS are observed on renal biopsy, early discontinuation of IFN-β is essential.

Treatment- and population-specific genetic risk factors for anti-drug antibodies against interferon-beta: a GWAS

BACKGROUND

Upon treatment with biopharmaceuticals, the immune system may produce anti-drug antibodies (ADA) that inhibit the therapy. Up to 40% of multiple sclerosis patients treated with interferon β (IFNβ) develop ADA, for which a genetic predisposition exists. Here, we present a genome-wide association study on ADA and predict the occurrence of antibodies in multiple sclerosis patients treated with different interferon β preparations.

METHODS

We analyzed a large sample of 2757 genotyped and imputed patients from two cohorts (Sweden and Germany), split between a discovery and a replication dataset. Binding ADA (bADA) levels were measured by capture-ELISA, neutralizing ADA (nADA) titers using a bioassay. Genome-wide association analyses were conducted stratified by cohort and treatment preparation, followed by fixed-effects meta-analysis.

RESULTS

Binding ADA levels and nADA titers were correlated and showed a significant heritability (47% and 50%, respectively). The risk factors differed strongly by treatment preparation: The top-associated and replicated variants for nADA presence were the HLA-associated variants rs77278603 in IFNβ-1a s.c.- (odds ratio (OR) = 3.55 (95% confidence interval = 2.81-4.48), p = 2.1 × 10-26) and rs28366299 in IFNβ-1b s.c.-treated patients (OR = 3.56 (2.69-4.72), p = 6.6 × 10-19). The rs77278603-correlated HLA haplotype DR15-DQ6 conferred risk specifically for IFNβ-1a s.c. (OR = 2.88 (2.29-3.61), p = 7.4 × 10-20) while DR3-DQ2 was protective (OR = 0.37 (0.27-0.52), p = 3.7 × 10-09). The haplotype DR4-DQ3 was the major risk haplotype for IFNβ-1b s.c. (OR = 7.35 (4.33-12.47), p = 1.5 × 10-13). These haplotypes exhibit large population-specific frequency differences. The best prediction models were achieved for ADA in IFNβ-1a s.c.-treated patients. Here, the prediction in the Swedish cohort showed AUC = 0.91 (0.85-0.95), sensitivity = 0.78, and specificity = 0.90; patients with the top 30% of genetic risk had, compared to patients in the bottom 30%, an OR = 73.9 (11.8-463.6, p = 4.4 × 10-6) of developing nADA. In the German cohort, the AUC of the same model was 0.83 (0.71-0.92), sensitivity = 0.80, specificity = 0.76, with an OR = 13.8 (3.0-63.3, p = 7.5 × 10-4).

CONCLUSIONS

We identified several HLA-associated genetic risk factors for ADA against interferon β, which were specific for treatment preparations and population backgrounds. Genetic prediction models could robustly identify patients at risk for developing ADA and might be used for personalized therapy recommendations and stratified ADA screening in clinical practice. These analyses serve as a roadmap for genetic characterizations of ADA against other biopharmaceutical compounds.

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.

Seasonal adherence to, and effectiveness of, subcutaneous interferon β-1a administered by RebiSmart® in patients with relapsing multiple sclerosis: results of the 1-year, observational GEPAT-SMART study

BACKGROUND

Little is known about whether tolerability and adherence to treatment can be influenced by weather and temperature conditions. The objective of this study was to assess monthly and seasonal adherence to and safety of sc IFN-β1a (Rebif®, Merck) in relapsing-remitting multiple sclerosis (RRMS) patients using the RebiSmart® electronic autoinjector.

METHODS

A multicentre, prospective observational study in Greece in adult RRMS patients with EDSS < 6, under Rebif®/RebiSmart® treatment for ≤6 weeks before enrollment. The primary endpoint was monthly, seasonal and annual adherence over 12 months (defined in text). Secondary endpoints included number of relapses, disability, adverse events.

RESULTS

Sixty four patients enrolled and 47 completed all study visits (Per Protocol Set - PPS). Mean annual adherence was 97.93% ± 5.704 with no significant monthly or seasonal variations. Mean relapses in the pre- and post- treatment 12-months were 1.1 ± 0.47 and 0.2 ± 0.54 (p < 0.0001, PPS). 10 patients (22%) showed 3-month disability progression, 19 (40%) stabilization and 18 (38%) improvement. EDSS was not correlated to pre- (r = 0.024, p = 0.87) or post-treatment relapses (r = 0.022, p = 0.88).

CONCLUSION

High adherence with no significant seasonal or weather variation was observed over 12 months. While the efficacy on relapses was consistent with published studies, we could not identify a relationship between relapses and disability.

TRIAL REGISTRATION

Greek registry of non-interventional clinical trials ID: 200136 , date of registration: February 18th, 2013.

Impact of adherence on subcutaneous interferon beta-1a effectiveness administered by Rebismart® in patients with multiple sclerosis

BACKGROUND

Adherence to disease-modifying drugs (DMDs) is one of the key factors for achieving optimal clinical outcomes. Rebismart^® is an injection device for subcutaneous administration of interferon beta-1a (INF β-1a) that is also able to monitor adherence objectively. The aim of this study was to describe adherence to INF β-1a using the said electronic autoinjection device and to explore the relationship between adherence and relapses in a Spanish cohort.

METHODS

This is a retrospective observational study in which 110 Spanish patients self-administered INF β-1a subcutaneously using an electronic autoinjection device between June 2010 and June 2015. The primary end point was the percentage of adherence measured by Rebismart^® to subcutaneous INF β-1a injections calculated as number of injections received in time period versus number of injections scheduled in time period. Other variables recorded were demographic and clinical data. Statistical analysis was performed using SPSS 19.0 software.

RESULTS

Median adherence for the total study period was 96.5% (interquartile range [IQR]: 91.1-99.1). Similar values were observed during the first 6 months: 98.7% (IQR: 91.3-100), and the last 6 months: 97.6% (IQR: 91.1-99.8). Median duration of treatment was 979 days (IQR: 613.8-1,266.8). During the entire treatment period, 77.3% of patients were relapse free and mean annualized relapse rate was 0.14 (standard deviation: 0.33). Increased adherence was associated with better clinical outcomes, leading to lower relapse risk (odds ratio: 0.953; 95% confidence interval: 0.912-0.995). Specifically, every percentage unit increase in adherence resulted in a 4.7% decrease in relapse.

CONCLUSION

Patients with multiple sclerosis who self-injected INF β-1a with Rebismart^® had excellent adherence, correlating with a high proportion of relapse-free patients and very low annualized relapse rate.

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™.

Adherence to, and effectiveness of, subcutaneous interferon β-1a administered by RebiSmart® in patients with relapsing multiple sclerosis: results of the 1-year, observational SMART study

BACKGROUND

Patients with multiple sclerosis who have poor adherence to treatment have a higher risk of relapse than adherent patients. This study assessed adherence to, and effectiveness and convenience of, treatment with subcutaneous (sc) interferon (IFN) β-1a (Rebif®, Merck Serono SA) 44 or 22 μg three times weekly in patients with relapsing multiple sclerosis (RMS) using the RebiSmart® electronic, multidose, autoinjector for 1 year.

STUDY DESIGN

European, multicentre, observational study among neurologists: inclusion criteria included RMS, Expanded Disability Status Scale score ≤ 6, sc IFN β-1a administered by RebiSmart for ≤ 6 weeks. The primary endpoint was cumulative adherence recorded by RebiSmart.

RESULTS

The safety population included 912 patients, 77.4% (n = 823) of whom completed the Month-12 visit. Mean (± standard deviation) cumulative adherence was 97.1 ± 7.3% (n = 791). The most common reason for missed injection was 'forgot to inject' (37.0%). At Month 12/ED, 79.5% of patients were relapse-free. Of 353 patients who rated the convenience of the device, 68.3% found injecting 'very easy'. No unknown safety issues were detected.

CONCLUSIONS

Patients with RMS self-injecting sc IFN β-1a with RebiSmart had excellent adherence at Month 12/ED, which was associated with good clinical outcomes and no unexpected safety issues. Patients rated RebiSmart as convenient and easy to use.

Evaluation of the impact of neutralizing antibodies on IFNβ response

IFNβ therapeutic action depends on a sequence of biological steps: i) the interaction between interferon beta (IFNβ) and its receptor (IFNAR) located at the cell surface of peripheral blood mononuclear cells; ii) activation of second messengers; iii) transcription of several genes containing specific ISRE regions (Interferon Stimulated Response Elements); and iv) synthesis of specific proteins. Although IFNβ therapy has improved treatment options of patients with multiple sclerosis (MS), the long-term efficacy of IFNβs can be compromised due to the development of neutralizing antibodies (NAbs). High titer NAbs develop in about 15% of patients; they abolish IFNβ biological activity and consequently the therapeutic action of IFNβ. Different IFNβ preparations carry different risks of developing NAbs, ranging from 3 to 28%. The risk of inducing NAbs must be considered in the selection of treatment. Guidelines for NAbs testing and the therapeutic decision in case of NAbs positivity have been established. NAbs positivity predicts MRI and clinical activity. Precocious identification of Nabs-positive patients and switch to alternative treatments can improve the percentage of responders and allow a better allocation of relevant economical resources.

Interferon-Beta: Neutralizing Antibodies, Binding Antibodies, Pharmacokinetics and Pharmacodynamics, and Clinical Outcomes

Antibodies to interferon-beta (IFNb) may occur during treatment with this drug and can be measured at several levels, the totality of antibodies referred to as antidrug antibodies (ADA) or binding antibodies, and in case of interference with the drug activity referred to as neutralizing antibodies (NAB). Antibodies can also interfere with the biological activity of IFNb as measured by pharmacodynamic markers. To get a complete picture of the interference between IFNb as a drug and the ADA, all the 3 above levels need to be considered. Furthermore, the interaction of these biomarkers changes over time with a shift of antibody properties with respect to immunoglobulin subtypes, affinity, and titers of antibodies. In case of persistent NAB, the clinical benefit of IFNb in the treatment of multiple sclerosis is abolished. In this report, the current knowledge on these issues will be reviewed. The data have been presented at a meeting in Coral Gables, Florida on April 18-21, 2012.

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.

Prevalence of anti-drug antibodies against interferon beta has decreased since routine analysis of neutralizing antibodies became clinical practice

BACKGROUND

Neutralizing antibodies (NAbs) against interferon beta (IFNβ) lead to loss of treatment efficacy in multiple sclerosis patients. The seroprevalence of NAbs in multiple sclerosis patients treated with IFNβ during 2003-2004 was 32% in a cross-sectional analysis of routine data.

OBJECTIVES

The aim of this study was to investigate whether the seroprevalence of NAbs, the levels of NAb titres and the IFNβ preparations used for treatment of multiple sclerosis patients had changed in 2009-2010.

METHODS

This study included 1296 patients, analysed for NAbs with the myxovirus resistance protein A gene expression assay in 2009-2010.

RESULTS

The seroprevalence of NAbs had decreased to 19% in 2009-2010, which is significantly lower compared with the previous study in 2003-2004 (p<0.0001). This decrease was attributed to the IFNβ-1a preparations only, not to IFNβ-1b. The frequency of patients with high positive titres decreased the most, from 16% to 7% (p<0.0001).

CONCLUSIONS

NAb seroprevalence has decreased since NAb monitoring became clinical practice in 2003, especially for patients with high NAb titres. This might be due to the stricter monitoring of NAb titres that prompt NAb positive patients to stop treatment, to preferential use of less immunogenic drugs and to alteration of drug formulations.

Immunogenicity of protein aggregates--concerns and realities

Protein aggregation is one of the key challenges in the development of protein biotherapeutics. It is a critical product quality issue as well as a potential safety concern due to the increased immunogenicity potential of these aggregates. The overwhelming safety concern has led to an increased development effort and regulatory scrutiny in recent years. The main purposes of this review are to examine the literature data on the relationship between protein aggregates and immunogenicity, to highlight the linkage and existing inconsistencies/uncertainties, and to propose directions for future investigations/development.

Development of resistance to biologic therapies with reference to IFN-β

All biotherapeutics have the potential to generate anti-drug antibodies (ADAs) in patients. The main factors leading to an immune response are thought to be product, treatment and patient related. In this review, reasons for the formation of ADAs, and particularly neutralizing antibodies (NAbs), are considered, with a focus on IFN-β as a well-studied example. The time course for the production of NAbs, the measurement of NAbs, the defining of IFN-β responders and non-responders, the implications for disease progression in patients, and future methods for avoiding the production of ADAs and of tolerizing patients are considered.

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.

Role of differential expression of interferon receptor isoforms on the response of multiple sclerosis patients to therapy with interferon beta

The cytokine interferon (IFN)-β is successfully used in the treatment of multiple sclerosis. However, some patients fail to respond to therapy, probably due to different biological patterns that are of importance in influencing clinical response. A common mechanism involved in the modulation of responsiveness to cytokine is represented by regulation of their receptor expression through autocrine-ligand-mediated loops. Mechanistically, IFN-β exerts its biological effects through interaction with the IFN-α/-β-receptor (IFNAR), which then activates several transcription factors. IFNAR is composed of 2 chains, IFNAR-1 and IFNAR-2, which associate with IFN-β to form a ternary complex. The major ligand-binding subunit is IFNAR-2 and it exists in 3 mRNA splice variants, resulting in 2 transmembrane (IFNAR-2b and IFNAR-2c) isoforms and a soluble (IFNAR-2a) one. On the contrary, from normal cells only one IFNAR-1 isoform, with transcriptional capacity, was identified. In the past decades, considerable information has accumulated pertaining to the downregulation of the IFNAR complex in IFN-treated patients, but only a few studies have investigated the molecular events involved in this phenomenon. The intent of the present review is to place this receptor downregulation in the context of IFN-β therapy and of its clinical and biological outcomes in IFN-β-treated patients.

Impact of product-related factors on immunogenicity of biotherapeutics

All protein therapeutics have the potential to be immunogenic. Several factors, including patient characteristics, disease state, and the therapy itself, influence the generation of an immune response. Product-related factors such as the molecule design, the expression system, post-translational modifications, impurities, contaminants, formulation and excipients, container, closure, as well as degradation products are all implicated. However, a critical examination of the available data shows that clear unequivocal evidence for the impact of these latter factors on clinical immunogenicity is lacking. No report could be found that clearly deconvolutes the clinical impact of the product attributes on patient susceptibility. Aggregation carries the greatest concern as a risk factor for immunogenicity, but the impact of aggregates is likely to depend on their structure as well as on the functionality (e.g., immunostimulatory or immunomodulatory) of the therapeutic. Preclinical studies are not yet capable of assessing the clinically relevant immunogenicity potential of these product-related factors. Simply addressing these risk factors as part of product development will not eliminate immunogenicity. Minimization of immunogenicity has to begin at the molecule design stage by reducing or eliminating antigenic epitopes and building in favorable physical and chemical properties.

Immune reconstitution syndrome and the thyroid

Reconstitution Graves' disease occurs in three settings. First, bone marrow transplantation from a donor with Graves' disease may cause this disease to appear in the recipient, as a result of adoptive immunity, although disordered immunoregulation secondary to graft-versus-host disease may also play a role. Second, alemtuzumab treatment for multiple sclerosis leads to the development of Graves' disease in up to a third of patients during the phase of naive T-cell expansion, which follows therapeutic lymphocyte depletion. Other reconstitution autoimmune phenomena, including immune thrombocytopaenic purpura, are also recognised after alemtuzumab administration. Finally, reconstitution Graves' disease may occur during a similar phase of CD4(+) T-cell expansion, which follows highly active antiretroviral therapy for human immunodeficiency virus infection. Again, this complication is part of a broader spectrum of immunoregulatory disturbances, which can arise after immune reconstitution. The mechanisms responsible for reconstitution Graves' disease are at present unclear, but may include a relative bias towards a Th2-mediated immune response and reduced competition for autoreactive lymphocytes to expand during the time when recovery from lymphopenia commences.

Improving compliance with interferon-beta therapy in patients with multiple sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease affecting young adults (with a peak of onset between the ages of 20 and 40 years). In 80-90% of cases, it is characterized by an early relapsing-remitting (RR) inflammatory phase, followed by a secondary progressive course in which disability progressively accumulates. Interferon-beta (IFNbeta) therapies represent the first-line treatment of RRMS. There are three IFNbeta formulations currently licensed for RRMS. Two are formulations of INFbeta-1a, one administered at a dosage of 30 mug intramuscularly weekly (Avonex(R)) and the other administered at a dosage of 22 or 44 microg subcutaneously (SC) three times a week (Rebif(R) 22 and 44). The third is a formulation of IFNbeta-1b, administered at a dosage of 250 microg SC every other day (Betaseron(R)). These treatments reduce the frequency of acute relapses and, to a lesser extent, disability progression. However, when starting an IFNbeta therapy, a treatment discontinuation rate ranging from 14% to 44% has to be expected. In a sizable proportion of patients, treatment suspension is caused by the occurrence of adverse effects (most commonly a flu-like syndrome and injection site reactions) and/or poor compliance. Individualized patient education and support are critical to improve adherence to therapy in the long term. Approaches aimed at reducing the proportion of subjects interrupting IFNbeta encompass both pharmacological and non-pharmacological interventions, and may involve several professional figures, such as the neurologist, the psychologist, the pharmacist, the physical and speech therapist, and the nurse. Recently, the development of new IFNbeta formulations, with reduced immunogenic potential, has offered an additional approach to improving patient adherence. Biferonex(R) is a pH neutral and human serum albumin-free IFNbeta-1a. A phase III, 2-year study of the product involving patients with RRMS has been conducted, but the results were not considered conclusive enough to allow approval in Europe. Rebif(R) New Formulation (RNF) is a formulation of INFbeta-1a that is not produced using fetal bovine serum and that does not have human serum albumin as an excipient. The formulation has been approved in Europe and an application for approval has been filed in the US. On the basis of the final analysis of a phase III trial, RNF showed higher tolerability, particularly in terms of injection site reactions, compared with the older formulation. Further studies assessing its usefulness as an alternative therapy for patients who are intolerant of other IFNbeta formulations are required.

Neutralizing antibodies to interferon-beta and other immunological treatments for multiple sclerosis: prevalence and impact on outcomes

Biopharmaceuticals can induce antibodies, which interact with and neutralize the therapeutic effect of such drugs and are therefore termed neutralizing antibodies (NAbs). In the treatment of multiple sclerosis, NAbs against interferon (IFN)-beta and natalizumab have been recognized. The prevalence of NAbs against different IFNbeta preparations varies widely, mainly depending on the product but also on other factors such as amino acid sequence variations, glycosylation, formulation, route and frequency of application, dose, duration of treatment and patient characteristics (human leukocyte antigen [HLA] status). IFNbeta-1a given intramuscularly induces significantly less NAbs than any other IFNbeta formulation. The longitudinal development of NAbs also differs between IFNbeta preparations, with higher reversion rates in IFNbeta-1b-treated compared with IFNbeta-1a-treated patients. The negative effect of NAbs on various outcome measures is very consistent across many studies, specifically when observation periods are longer than 2 years. NAbs against natalizumab occur less frequently (6%) and, like NAbs against IFNbeta, they are associated with a loss of clinical and radiological efficacy of the drug.

Safety and immunogenicity of a new formulation of interferon beta-1a (Rebif New Formulation) in a Phase IIIb study in patients with relapsing multiple sclerosis: 96-week results

BACKGROUND

A new formulation of subcutaneous (s.c.) interferon-beta-1a has been developed (Rebif New Formulation, RNF), produced without fetal bovine serum and without human serum albumin as an excipient, with the aim of improving injection tolerability, and reducing immunogenicity.

OBJECTIVES

This article reports 96-week analyses of a Phase IIIb, open-label study of the safety and immunogenicity of RNF compared with historical (EVIDENCE study) and recent (REGARD study) data on the original formulation.

METHODS

Patients with relapsing multiple sclerosis (McDonald criteria) and an Expanded Disability Status Scale score < 6.0 received RNF, 44 microg s.c. three times weekly.

RESULTS

The proportion of neutralizing antibody-positive (NAb+) patients (serum NAb status >or=20 neutralizing units/mL) at week 96 (last observation carried forward; primary endpoint) was 17.4% (exact 95% confidence interval [CI]: 13.0-22.5), compared with 21.4% (95% CI: 17.2-26.2) in the EVIDENCE study, and 27.3% (95% CI: 22.8-32.1) in the REGARD study. The proportion of patients NAb+ at any time during the 96 weeks was 18.9% (95% CI: 14.4-24.2), compared with 27.1% (95% CI: 22.4-32.2) and 33.7% (95% CI: 28.9-38.7), respectively. Most pre-specified categories of adverse events were reported by patients in the RNF study at a similar or lower proportion than in the EVIDENCE and REGARD studies. Injection-site reactions were experienced by fewer patients than in the EVIDENCE and REGARD studies.

CONCLUSIONS

RNF has improved overall immunogenicity and safety profiles compared with the original formulation.

[Subcutaneous interferon-beta-1a in the treatment of multiple sclerosis]

During the last 10 years recombinant interferon-beta-1a administered subcutaneously has been the subject of several clinical trials in relapsing remitting multiple sclerosis (RRMS), in secondary progressive MS (SPMS), as well as in clinically isolated syndromes. All of them met the criteria of evidence level class I. Consistent evidence for moderate immunomodulatory effects on clinical parameters of disease activity was gained, and even higher efficacy of IFN-beta-1a sc. on MRI activity of multiple sclerosis was proven. Indirect evidence confirmed the hypothesis of a dose-response curve for IFN-beta-1a formulations in MS. The higher efficacy of IFN-beta-1a 44 microg sc. TIW, however, also includes more adverse events such as injection site reactions, flu-like symptoms and a moderate immunogenicity. Current evidence does not allow a recommendation of IFN-beta-1a sc. as most effective first line therapy, because also the individual patient's choice in the route of administration and long-term effects of neutralizing antibodies to IFN-beta-1a sc. must be taken into account. In the long-term, IFN-beta-1a showed a beneficial safety-tolerability profile with 50 % of patients sticking to the initial immunomodulatory treatment. There were no teratogenic effects, IFN-beta-1a sc. did not enhance depressive symptoms. Data on inhibition of the progression of disease, however, remained inconclusive. Probable beneficial effects of IFN-beta-1a sc. on cognitive function or "chronic fatigue" have not been investigated yet.

The Rebif new formulation story: it's not trials and error

The rapid evolution of the biopharmaceutical industry and the development of innovative technologies have provided an opportunity to improve recombinant interferon (IFN)-beta formulations. A number of strategies have been developed to improve the stability, tolerability and immunogenicity of IFNbeta formulations that are used in the long-term treatment of patients with multiple sclerosis (MS). This review focuses on the production of recombinant IFNs and discusses the development of one such biopharmaceutical, Rebif New Formulation (RNF).RNF was developed with the aim of further improving the tolerability and immunogenicity of Rebif, an approved IFNbeta-1a formulation administered subcutaneously three times per week (sc tiw). To this end, numerous candidate drug vehicles and formulations were developed. However, unlike other formulations of IFNbeta, the new candidate formulations in this case were free from all serum-derived components. Specifically, each RNF candidate was free from human serum albumin and produced without fetal bovine serum. The physicochemical stability, injection-site tolerability, pharmacokinetic profile and immunogenic potential of each candidate formulation were systematically tested. This involved initial screening of a large pool of formulations for promising candidates. Two candidate formulations were selected and subjected to further, extensive evaluation.Ex vivo T-cell assays were used to compare the immunogenicity of RNF candidates with that of the current (at the time of writing) approved formulation and an IFNbeta standard. A single RNF candidate induced less T-cell activation, in terms of proliferation and proinflammatory cytokine secretion, than the other two formulations. The results provided ex vivo evidence of the improved immunogenic potential of RNF. A murine model was used to compare the relative immunogenicity of RNF in vivo with two approved formulations of IFNbeta-1a. Mice treated with RNF developed neutralising antibodies more slowly and produced lower titres than mice treated with equivalent doses of the current IFNbeta-1a sc tiw formulation or another approved IFNbeta-1a formulation administered intramuscularly once per week (Avonex). RNF also demonstrated better local tolerability than the current IFNbeta-1a sc tiw formulation after single subcutaneous doses in healthy volunteers. One RNF candidate was superior to the others in all preclinical and phase I studies, and was chosen as the final RNF. This formulation is currently undergoing assessment in a 96-week, phase IIIb clinical trial in patients with MS. This single-arm, open-label, multicentre study will compare the immunogenicity and tolerability of RNF with historical data on the current formulation; results of a 48-week, interim analysis indicate that RNF has improved local tolerability and immunogenicity compared with the current formulation. It is anticipated that the benefits of RNF will translate into an improved long-term benefit-to-risk profile. Further assessment of RNF and other MS drugs is ongoing with the aim of enhancing the therapeutic options available for patients with MS.

Subcutaneous interferon-beta-1a : new formulation

The new formulation of subcutaneous interferon-beta-1a was developed without serum-derived components with the aim of improving immunogenicity and injection tolerability in patients with relapsing forms of multiple sclerosis (MS). In a prospectively defined interim analysis at 48 weeks of an ongoing, single-arm, phase IIIb trial, 13.9% of MS patients receiving the new formulation of subcutaneous interferon-beta-1a 44 microg three times weekly had developed neutralising antibodies (NAbs). In the EVIDENCE trial, which served as an historical control, 24.4% of patients receiving the same dosage of the current formulation had developed NAbs at 48 weeks. The new formulation demonstrated similar pharmacokinetic activity to that of the current formulation in a phase I, double-blind, placebo-controlled study in healthy volunteers. About two-thirds of patients with MS who received the new formulation of subcutaneous interferon-beta-1a were relapse free in the interim, 48-week analysis of the single-arm trial; this is similar to results for the current formulation from historical data. A comparison of results from the interim, 48-week analysis with historical-control data from the EVIDENCE trial indicates that the new formulation of interferon-beta-1a may be associated with a lower incidence of injection-site reactions and a higher incidence of influenza-like symptoms than the current formulation. Adverse events associated with the new formulation were mostly mild to moderate in severity

Emerging oral therapies for multiple sclerosis

BACKGROUND

Current disease-modifying drugs (DMDs) have positively affected the treatment of relapsing-remitting multiple sclerosis (RRMS); however, the requirement for long-term injections imposes a burden on patients and may lead to reduced adherence in some cases. Furthermore, not all patients respond adequately to current DMDs, suggesting that certain patients require different therapeutic approaches. Therefore, alternative MS treatments with less invasive routes of administration and new modes of action are needed to expand the current treatment repertoire, increase patient satisfaction and adherence, and thereby improve efficacy.

DISCUSSION

This review discusses the current unmet need for an orally administered treatment for RRMS, including potential benefits of this route of administration, and implications for improved treatment outcomes. Oral drugs that are currently in Phase II/III clinical development are discussed.

Using measurements of neutralizing antibodies: the challenge of IFN-? therapy

Although the occurrence of neutralizing antibodies (NAbs) to interferon (IFN)-beta has been acknowledged since the pivotal trials of IFN-beta in multiple sclerosis (MS), the effect of these antibodies has for several reasons been debated. The main reason for the controversies has been insufficient knowledge of the fact that clinically relevant NAbs do not appear until 12-18 months after initiation of IFN-beta therapy which make studies of 2 years or less unsuited to assess the clinical relevance of NAbs. Further, changes in NAb affinity occur and contribute to increase NAb effects by time. The present paper reviews our current knowledge of NAbs and stresses the importance of using measurements of NAbs routinely. It is concluded that NAb titres are important for the biological response to IFN-beta. Patients with low or intermediate titres may have preserved a full or partial biological response and might still benefit from IFN-beta therapy. However, persistent high titres 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. The application of the existing information about NAbs in clinical practice would lead to improved efficacy of IFN-beta treatment for the benefit of patients with MS.