Swedish natalizumab (Tysabri) multiple sclerosis surveillance study

Trajectories of cognitive processing speed and physical disability over 11 years following initiation of a first multiple sclerosis disease-modulating therapy

BACKGROUND

We analysed the COMparison Between All immunoTherapies for Multiple Sclerosis (NCT03193866), a Swedish nationwide observational study in relapsing-remitting multiple sclerosis (RRMS), to identify trajectories of processing speed and physical disability after disease-modulating therapy (DMT) start.

METHODS

Using a group-modelling approach, we assessed trajectories of processing speed with oral Symbol Digit Modalities Test (SDMT) and physical disability with Expanded Disability Status Scale, from first DMT start among 1645 patients with RRMS followed during 2011-2022. We investigated predictors of trajectories using group membership as a multinomial outcome and calculated conditional probabilities linking membership across the trajectories.

RESULTS

We identified 5 stable trajectories of processing speed: low SDMT scores (mean starting values=29.9; 5.4% of population), low/medium (44.3; 25.3%), medium (52.6; 37.9%), medium/high (63.1; 25.8%) and high (72.4; 5.6%). We identified 3 physical disability trajectories: no disability/stable (0.8; 26.8%), minimal disability/stable (1.6; 58.1%) and moderate disability (3.2; 15.1%), which increased to severe disability. Older patients starting interferons were more likely than younger patients starting rituximab to be on low processing speed trajectories. Older patients starting teriflunomide, with more than one comorbidity, and a history of pain treatment were more likely to belong to the moderate/severe physical disability trajectory, relative to the no disability one. There was a strong association between processing speed and physical disability trajectories.

CONCLUSIONS

In this cohort of actively treated RRMS, patients' processing speed remained stable over the years following DMT start, whereas patients with moderate physical disability deteriorated in physical function. Nevertheless, there was a strong link between processing speed and disability after DMT start.

Deficit of homozygosity among 1.52 million individuals and genetic causes of recessive lethality

Genotypes causing pregnancy loss and perinatal mortality are depleted among living individuals and are therefore difficult to find. To explore genetic causes of recessive lethality, we searched for sequence variants with deficit of homozygosity among 1.52 million individuals from six European populations. In this study, we identified 25 genes harboring protein-altering sequence variants with a strong deficit of homozygosity (10% or less of predicted homozygotes). Sequence variants in 12 of the genes cause Mendelian disease under a recessive mode of inheritance, two under a dominant mode, but variants in the remaining 11 have not been reported to cause disease. Sequence variants with a strong deficit of homozygosity are over-represented among genes essential for growth of human cell lines and genes orthologous to mouse genes known to affect viability. The function of these genes gives insight into the genetics of intrauterine lethality. We also identified 1077 genes with homozygous predicted loss-of-function genotypes not previously described, bringing the total set of genes completely knocked out in humans to 4785.

Comparative effectiveness of natalizumab on cognition in multiple sclerosis: A cohort study

BACKGROUND

Cognitive impairment occurs in 40%-70% of persons with multiple sclerosis (MS).

OBJECTIVE

To examine the effectiveness of natalizumab compared with other disease-modifying treatments (DMTs) on improving cognition as measured by the Symbol Digit Modalities Test (SDMT).

METHODS

Data were collected as part of Swedish nationwide phase IV surveillance studies (2007-2020). An increase in SDMT score by ⩾10% of the difference between maximum score possible (110) and the baseline value was defined as cognitive improvement. The likelihood of improvement was compared between natalizumab-treated individuals and individuals treated with other DMTs using mixed effect logistic regression. Trend in odds of improvement was investigated using slope analyses.

RESULTS

We included 2100 persons with relapsing-remitting MS treated with natalizumab and 2622 persons treated with other DMTs. At 6 months, 45% reached improvement. The natalizumab group showed largest odds of improvement during follow-up (odds ratio: 2.3, 95% confidence interval (CI): 1.5-3.5). The odds of improvement increased by 7% (95% CI: 6-7) per month of natalizumab treatment. The equivalent estimate was 4% (95% CI: 2-5) for other monoclonal antibodies and nonsignificant for oral or platform therapies.

CONCLUSION

Treatment with natalizumab or other monoclonal antibodies is associated with a significantly faster likelihood of cognitive improvement than platform or oral DMTs.

Serum IgG levels to Epstein-Barr and measles viruses in patients with multiple sclerosis during natalizumab and interferon beta treatment

Background

Patients with multiple sclerosis (MS) demonstrate higher seroprevalence of Epstein-Barr virus (EBV) and increased anti-EBV IgG levels in serum compared with healthy controls. Intrathecal antibody production to measles virus (MeV) is a common finding in patients with MS.

Objective

To measure serum IgG reactivity to EBV glycoprotein 350 (gp350) and MeV nucleocapsid protein (N_CORE) in patients with MS and healthy controls and to determine if reactivity changed in patients during interferon beta (IFNβ) and/or natalizumab (NAT) treatment. A secondary aim was to determine the seroprevalence of EBV in patients and controls.

Methods

Patients with MS (n=728) were included from the Swedish pharmacovigilance study for NAT. Paired serum samples from 714 patients drawn before and during NAT treatment and paired samples from 170 patients during prior IFNβ treatment were analysed. In total, 156 patients were included in both groups. Samples from 144 matched blood donors served as controls. Indirect ELISA was applied using recombinant EBVgp350 and MeV N_CORE as antigens. EBVgp350 IgG seronegative samples were also analysed using EBV nuclear antigen 1 and viral capsid antigen (VCA).

Results

Patients with MS showed higher serum levels of anti-EBVgp350 and anti-MeV N_CORE IgG compared with controls. During NAT treatment, the levels of anti-EBVgp350 and anti-MeV N_CORE IgG declined, compared with the relatively stable levels noted during prior IFNβ treatment. Ten patients failed to demonstrate anti-EBVgp350 IgG but did show detectable anti-VCA IgG, indicating EBV seropositivity. In contrast, 10/144 controls were EBV seronegative.

Conclusions

Treatment with NAT, which is considered a selective immunosuppressive agent with a compartmentalised effect on the central nervous system, appeared to be associated with a moderate decrease in circulating IgG levels to EBVgp350 and MeV N_CORE. All patients with MS were EBV IgG seropositive, supporting the potential role of EBV in the pathogenesis of MS.

Early vs. late treatment initiation in multiple sclerosis and its impact on cost of illness: A register-based prospective cohort study in Sweden

Background

Early treatment with disease modifying therapies (DMTs) for multiple sclerosis (MS) has been associated with lower disability progression; the aim was to explore its association with cost of illness (COI) in MS.

Methods

All people with relapsing-remitting MS in the Swedish MS register, aged 20–57 years and receiving their first MS DMT in 2006–2009, were followed in nationwide registers for 8 years. Healthcare costs (in- and outpatient healthcare, DMTs and other prescribed drugs), and productivity losses (sickness absence and disability pension) of individuals receiving therapy in ≤6 months after diagnosis (early treatment group) were compared to those receiving therapy >6 months (late treatment group). Using Poisson regressions, the mean COI per patient per year, and per group, was estimated, adjusted for disability progression.

Results

The early treatment group comprised 74% of the 1562 individuals included in the study. The early treatment group had lower productivity losses over time. Both groups had similar healthcare costs, which first increased and then decreased over time.

Conclusions

Early DMT in MS could result in lower productivity losses possibly through maintained work capacity. COI serves as an objective measure showing the advantage of early vs. late treatment initiation in MS.

Season of birth is associated with multiple sclerosis and disease severity

BACKGROUND

The latitude gradient in multiple sclerosis incidence indicates that low sun exposure and therefore vitamin D deficiency is associated with multiple sclerosis risk.

OBJECTIVE

Investigation of the effect of month of birth, which influences postnatal vitamin D levels, on multiple sclerosis risk and severity in Sweden.

METHODS

Patients and population-based controls were included from three nationwide cohorts. Differences in month of birth between cases and controls were analyzed using logistic regression and examined for effect modification by calendar year and geographic region at birth.

RESULTS

Males had a reduced risk of multiple sclerosis if born in the winter and increased risk if born in the early fall. Individuals born before 1960 had an increased risk if born in summer or fall. Being born in late summer and early fall was associated with more severe disease.

CONCLUSIONS

We identified a birth cohort effect on the association between the month of birth and multiple sclerosis, with a more significant effects for births before 1960. This coincides with a period of lower breastfeeding rates, recommended intake of vitamin D, and sun exposure, resulting in a lower vitamin D exposure during the fall/winter season for infants born in the summer.

PML risk is the main factor driving the choice of discontinuing natalizumab in a large multiple sclerosis population: results from an Italian multicenter retrospective study

BACKGROUND

Natalizumab (NTZ) is an effective treatment for relapsing-remitting multiple sclerosis (RRMS). However, patients and physicians may consider discontinuing NTZ therapy due to safety or efficacy issues. The aim of our study was to evaluate the NTZ discontinuation rate and reasons of discontinuation in a large Italian population of RRMS patients.

MATERIALS AND METHODS

The data were extracted from the Italian MS registry in May 2018 and were collected from 51,845 patients in 69 Italian multiple sclerosis centers. MS patients with at least one NTZ infusion in the period between June 1st 2012 to May 15th 2018 were included. Discontinuation rates at each time point were calculated. Reasons for NTZ discontinuation were classified as "lack of efficacy", "progressive multifocal leukoencephalopathy (PML) risk" or "other".

RESULTS

Out of 51,845, 5151 patients, 3019 (58.6%) females, with a mean age of 43.6 ± 10.1 years (median 40), were analyzed. Out of 2037 (39.5%) who discontinued NTZ, a significantly higher percentage suspended NTZ because of PML risk compared to lack of efficacy [1682 (32.7% of 5151) vs 221 (4.3%), p < 0.001]; other reasons were identified for 99 (1.9%) patients. Patients discontinuing treatment were older, had longer disease duration and worse EDSS at the time of NTZ initiation and at last follow-up on NTZ treatment. The JCV index and EDSS at baseline were predictors for stopping therapy (HR 2.94, 95% CI 1.22-4.75; p = 0.02; HR 1.36, 95% CI 1.18-5.41; p = 0.04).

CONCLUSIONS

Roughly 60% of MS patients stayed on NTZ treatment during the observation period. For those patients in whom NTZ discontinuation was required, it was mainly due to PML concerns.

Reduction of the risk of PML in natalizumab treated MS patients in Sweden: An effect of improved PML risk surveillance

BACKGROUND

Natalizumab (NTZ) treatment of multiple sclerosis (MS) has been associated with increased risk of progressive multifocal leukoencephalopathy (PML). The aim of the present study was to evaluate the impact of PML risk assessment on PML incidence in NTZ treated MS patients.

METHODS

By using information from the population-based Swedish MS registry a retrospective cohort was established of patients treated with NTZ between 2006-2018. The effect on PML incidence before and after utilizing a risk management plan, including JC virus (JCV) serology, was analyzed.

RESULTS

In December 2018, 804 PML cases associated with NTZ therapy of MS had been reported globally, including 9 cases from Sweden. The estimated PML incidence 2018 in Sweden and globally was 0.7 (0.3-1.4) and 4.15 (3.9-4.4) per 1,000 person years, respectively. In Sweden, JCV serology was introduced 2012 for PML risk assessment and the cumulative risk of PML was significantly lower 2012-2018 compared to the period 2006-2011 (p=0.042). The mean NTZ exposure time was 60.1 months (SD 37.2) in the first period (2006-2011) and 32.6 months (SD 22.0) in the second period (2012-2018). The number of patients treated with NTZ decreased, and the number of patients at increased risk of PML was 1.9 % at the end of the study period.

CONCLUSION

Since 2006 the incidence of PML associated with NTZ treatment of MS has decreased in Sweden. Our findings suggest that this reduction is due to an effective adoptation and adherence to the established risk management plan that implies switching patients at increased PML risk from NTZ to other highly efficacious therapies. A less pronounced decline in PML incidence has recently been observed in France, but not globally.

Mucosal Administration of E-selectin Limits Disability in Models of Multiple Sclerosis

E-selectin plays an important role in mediating the rolling of leukocytes along and thus, the subsequent extravasation across activated endothelial cells comprising the microvasculature of the blood brain barrier (BBB). In multiple sclerosis (MS) and other inflammatory disorders of the central nervous system (CNS), the microvasculature is altered and immune cells infiltrate the brain and spinal cord contributing to damage, demyelination and ultimately disability. While mucosal administration is typically used to affect lymphocyte hyporesponsiveness or tolerance to suspect autoantigens, intranasal administration to E-selectin has previously been shown to protect against CNS inflammatory insults. We characterized the potential for mucosal administration of E-selectin to modulate CNS autoimmunity in the experimental autoimmune encephalomyelitis (EAE) model of MS. Intranasally administered E-selectin reduced swelling by as much as 50% in delayed-type hypersensitivity reactions compared to ovalbumin-tolerized controls. Intranasal E-selectin delivery prior to disease induction with myelin oligodendrocyte glycoprotein (MOG)_35-55 reduced disease severity and total disease burden by more than 50% compared to PBS-tolerized animals; this protection was not associated with differences in the magnitude of the autoimmune response. Examination after the onset of disease showed that protection was associated with significant reductions in inflammatory infiltrates throughout the spinal cord. Tolerization to E-selectin did not influence encephalitogenic characteristics of autoreactive T cells such as IFN-gamma or IL-17 production. Clinical disease was also significantly reduced when E-selectin was first delivered after the onset of clinical symptoms. Splenic and lymph node (LN) populations from E-selectin-tolerized animals showed E-selectin-specific T cell responses and production of the immunomodulatory cytokine IL-10. Transfer of enriched CD4+ T cells from E-selectin tolerized mice limited disability in the passive SJL model of relapsing remitting MS. These results suggest a role for influencing E-selectin specific responses to limit neuroinflammation that warrants further exploration and characterization to better understand its potential to mitigate neurodegeneration in disorders such as MS.

Long-term Cognitive Outcomes in Patients With Pediatric-Onset vs Adult-Onset Multiple Sclerosis

Importance

Cognitive impairment in multiple sclerosis (MS) can lead to reduced quality of life, social functioning, and employment. Few studies have investigated cognitive outcomes among patients with pediatric-onset MS (POMS) over the long term.

Objective

To compare long-term information-processing efficiency between patients with POMS and adult-onset MS (AOMS).

Design, Setting, and Participants

This population-based longitudinal cohort study accessed the Swedish MS Registry (SMSreg), which collates information from all 64 neurology clinics in Sweden. Registered cases with definite MS in the SMSreg with an onset before April 15, 2018, and at least 2 Symbol Digit Modalities Test (SDMT) scores recorded were included. Only persons aged 18 to 55 years and with duration of disease of less than 30 years at the time of SDMT administration were included, to ensure comparable ranges between patients with POMS and AOMS. Of 8247 persons with an SDMT recorded in the SMSreg, 5704 met inclusion criteria, 300 (5.3%) of whom had POMS. Data were collected from April 1, 2006, through April 15, 2018 and analyzed from April through August 2018.

Exposures

Pediatric-onset MS (onset <18 years of age) vs AOMS (onset ≥18 years of age).

Main Outcomes and Measures

Information-processing efficiency measured every 6 or 12 months by the SDMT. Linear mixed-effects models were used to compare all available SDMT scores between patients with POMS and those with AOMS. Persons with cognitive impairment (ever vs never) were identified using regression-based norms and compared between POMS and AOMS groups using logistic regression.

Results

Of the 5704 participants, 4015 were female (70.4%), and 5569 had a relapsing-onset disease course (97.6%). Most participants were exposed to a disease-modifying therapy (DMT) during follow-up (98.8%). Median age at baseline for the POMS group was 25.6 years (interquartile range, 21.0-31.7 years) and for the AOMS group, 38.3 years (interquartile range, 31.4-45.2 years). A total of 46 429 unique SDMT scores were analyzed. After adjustment for sex, age, disease duration, disease course, total number of SDMTs completed, oral or visual SDMT form, and DMT exposure, the SDMT score for patients with POMS was significantly lower than that of patients with AOMS (β coefficient, -3.59 [95% CI, -5.56 to -1.54]). The SDMT score for patients with POMS declined faster than that of patients with AOMS (β coefficient, -0.30 [95% CI, -0.42 tp -0.17]). The odds of cognitive impairment were also significantly elevated in the POMS group (odds ratio, 1.44; 95% CI, 1.06-1.98).

Conclusions and Relevance

In adulthood, patients with POMS demonstrated a more rapid reduction in information-processing efficiency over time and were more likely to experience cognitive impairment than patients with AOMS, independent of age or disease duration. Further investigation is required to understand the mechanisms by which early MS onset influences cognitive outcomes.

The Anti-Inflammatory Effect of Sulforaphane in Mice with Experimental Autoimmune Encephalomyelitis

BACKGROUND

Multiple sclerosis (MS) is an immune-associated inflammatory disorder of the central nervous system and results in serious disability. Although many disease-modifying therapy drugs have been developed, these drugs have shown limited clinical efficacy and some adverse effects in previous studies, therefore, there has been reasonable need for less harmful and cost-effective therapeutics. Herein, we tested the anti-inflammatory effect of sulforaphane (SFN) in a mouse model of experimental autoimmune encephalomyelitis (EAE).

METHODS

The EAE mice were randomly assigned into two experimental groups: the phosphate-buffered saline (PBS)-treated EAE group and SFN-treated EAE group. After EAE mice induction by auto-immunization against the myelin oligodendrocyte glycoprotein peptide, we evaluated EAE symptom scores and biochemical analyses such as infiltration of inflammatory cells and demyelination of the spinal cord. Furthermore, western blotting was performed using the spinal cords of EAE mice.

RESULTS

In the behavioral study, the SFN-treated EAE mice showed favorable clinical scores compared with PBS-treated EAE mice at the 13th day (1.30 ± 0.15 vs. 1.90 ± 0.18; P = 0.043) and 14th day (1.80 ± 0.13 vs. 2.75 ± 0.17; P = 0.003). Additionally, the biochemical studies revealed that SFN treatment inhibited the inflammatory infiltration, demyelinating injury of the spinal cords, and the up-regulation of inducible nitric oxide synthase in the EAE mice.

CONCLUSION

The SFN treatment showed anti-inflammatory and anti-oxidative effects in the EAE mice. Conclusively, this study suggests that SFN has neuroprotective effects via anti-inflammatory processing, so it could be a new therapeutic or nutritional supplement for MS.

Observational designs in clinical multiple sclerosis research: Particulars, practices and potentialities

Observational studies investigate a wide range of topics in multiple sclerosis research. This paper presents an overview of the various observational designs and their applications in clinical studies. Observational studies are well suited for making discoveries and assessing new explanations of phenomena, but less so for establishing causal relationships, due to confounding by indication (selection bias), co-morbidity, socio-economic or other factors. Whether observational findings are demonstrative, indicative or only suggestive, depends on the research question, whether and how the design fits this question, analytical techniques, and the quality of data. Observational studies may be cross-sectional vs. longitudinal, and prospective vs. retrospective. The term 'retrograde' is proposed to explicate that cross-sectional studies may obtain data that cover (long) preceding periods. Case reports and case series are usually based on accidental observations or routinely collected data. Cross-sectional studies, by simultaneously assessing clinical phenomena and external factors, enable the discovery and quantification of associations. In ecological studies the unit of analysis is population or group, and relationships on patient level cannot be established. A cohort study is a longitudinal study that investigates patients with a defining characteristic, e.g. diagnosis or specific treatment, by analyzing data acquired at various intervals. Prospective cohort studies use (some) data that are not yet available at the time the research is conceived, whereas in retrospective studies the data already exist. In a case-control study a representative group of patients with a specific clinical feature is compared with controls, and the frequencies at which an external factor, e.g. infection, has occurred in each group is compared; in a nested case-control study controls are drawn from a fully known cohort. Randomized controlled trial (RCT)-extension studies are informative because, due to RCT randomization, they are free from confounding by indication. Patient or disease registries are organised systems for the long-term collection of uniform data on a population that is defined by a particular disease, condition or exposure, with the purpose to study changes over time. In pharmacotherapeutic research, accidental observations of unexpected beneficial effects may lead to further research into a drug's efficacy in other conditions. Uncontrolled phase 1 studies investigate safety and dosing aspects. Observational studies are alternatives to RCTs when these are not feasible for ethical or practical reasons. Phase 4 observational studies play a crucial role in the evaluation of the effectiveness of treatments in daily practice, the validation of RCT-based side effect profiles, and the discovery of late occurring or rare, potentially life-threatening side effects. Combinations of multidisciplinary longitudinal data bases into large data sets enable the development of algorithms for personalized treatments. To improve the reporting of observational findings on treatment effectiveness, it is proposed that abstracts define the research question(s) the study was meant to answer, study design and analytical methods, and identify and quantify the patient population, treatment of interest, relevant outcomes and the study's strengths and limitations. The development of guidelines for Strengthening the Reporting of Observational Studies in Effectiveness Research (STROBER), as an extension of the guidelines used in epidemiology, is wanted.

Natalizumab: Perspectives from the Bench to Bedside

Probably no other disease-modifying drug for multiple sclerosis has a more fascinating story than natalizumab from both the bench to bedside perspective and the postmarketing experience standpoint. Natalizumab is a monoclonal antibody that inhibits the trafficking of lymphocytes from the blood into the central nervous system by blocking the adhesion molecule α4-integrin. Natalizumab was approved as a disease-modifying drug for relapsing remitting multiple sclerosis only 12 years after the discovery of its target molecule-a time line that is rather fast for drug development. However, a few months after its U.S. Food and Drug Administration approval, natalizumab was withdrawn from the market because of an unanticipated complication-progressive multifocal leukoencephalopathy. It was later reinstated with required adherence to a strict monitoring program and incorporation of mitigation strategies.

Flow Cytometry-Defined CD49d Expression in Circulating T-Lymphocytes Is a Biomarker for Disease Progression in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) affects 1:3500-1:5000 male births, and is caused by X-linked mutations in the dystrophin gene, manifested by progressive muscle weakness and wasting due to the absence of dystrophin protein, leading to degeneration of skeletal muscle. DMD patients are clinically heterogeneous and the functional phenotype often cannot be correlated with the genotype. Therefore, defined reliable noninvasive biomarkers aiming at predicting if a given DMD child will progress more or less rapidly will be instrumental to better design inclusion of defined patients for future therapeutic assays. We recently showed that CD49d expression levels in blood-derived T-cell subsets can predict disease progression in DMD patients. Herein we describe in detail the methodology to be applied for defining, through four-color flow cytometry, the membrane expression levels of the CD49d (the α4 chain of the integrins α4β1 and α4β7) in circulating CD4⁺ and CD8⁺ T cell subsets. Since we have also shown that this molecule can also be placed as a potential target for therapeutics in DMD, we also describe the cell migration functional assay that can be applied to test potential CD49d inhibitors that can modulate their ability to cross endothelial or extracellular matrix (ECM) barriers.

Modulating inflammation and neuroprotection in multiple sclerosis

Multiple sclerosis (MS) is a neurological disorder of the central nervous system with a presentation and disease course that is largely unpredictable. MS can cause loss of balance, impaired vision or speech, weakness and paralysis, fatigue, depression, and cognitive impairment. Immunomodulation is a major target given the appearance of focal demyelinating lesions in myelin-rich white matter, yet progression and an increasing appreciation for gray matter involvement, even during the earliest phases of the disease, highlights the need to afford neuroprotection and limit neurodegenerative processes that correlate with disability. This review summarizes key aspects of MS pathophysiology and histopathology with a focus on neuroimmune interactions in MS, which may facilitate neurodegeneration through both direct and indirect mechanisms. There is a focus on processes thought to influence disease progression and the role of oxidative stress and mitochondrial dysfunction in MS. The goals and efficacy of current disease-modifying therapies and those in the pipeline are discussed, highlighting recent advances in our understanding of pathways mediating disease progression to identify and translate both immunomodulatory and neuroprotective therapeutics from the bench to the clinic.

Natalizumab treatment of multiple sclerosis: new insights

Natalizumab is a monoclonal antibody directed against the α4 chain of the very late activating antigen 4 and α4β7 integrins, present on the leukocytes surface, used as monotherapy for the treatment of relapsing-remitting multiple sclerosis. It substantially reduces relapse rate and the accumulation of disability, but its use is associated with a very adverse event, that is the development of progressive multifocal leukoencephalopathy, a fatal demyelinating disease of the CNS, due to the lytic replication of the human polyomavirus JC. The main focus of the review is to describe the newest insights on natalizumab, its current use in the clinical practice, the natalizumab-treated patients' management and the risk stratification related to the progressive multifocal leukoencephalopathy development.

Effectiveness and safety of natalizumab in real-world clinical practice: Review of observational studies

Clinical trials have shown that natalizumab is highly effective for treating relapsing forms of multiple sclerosis (MS). The purpose of this analysis was to conduct a targeted review of data from country-specific observational studies and registries of natalizumab-treated patients with relapsing MS in order to more fully investigate the longer-term effectiveness and safety of this disease-modifying therapy in real-world clinical practice settings. A PubMed search was conducted on March 13, 2014, using the terms (natalizumab AND multiple sclerosis) AND (observational OR registry OR post-marketing OR clinical practice). Only English-language papers that reported effectiveness (in terms of effects on relapses, disability progression, and magnetic resonance imaging findings) and/or safety results from studies were included. Data from 22 studies/registries were included. Annualized relapse rates decreased by 73%-94% from baseline across the studies, with improvement maintained for up to 5 years during natalizumab treatment. Natalizumab effectiveness was also demonstrated via assessment of disability progression (Expanded Disability Status Scale), radiological measures, and no-evidence-of-disease-activity measures (clinical, radiological, and overall). Results were similar among patient groups stratified by level of disease activity. Safety outcomes were consistent with natalizumab's known safety profile. Data from country-specific observational studies and registries varying in size and scope support the effectiveness and safety of natalizumab in a broad range of patients in clinical practice.

Drug-associated progressive multifocal leukoencephalopathy: a clinical, radiological, and cerebrospinal fluid analysis of 326 cases

The implementation of a variety of immunosuppressive therapies has made drug-associated progressive multifocal leukoencephalopathy (PML) an increasingly prevalent clinical entity. The purpose of this study was to investigate its diagnostic characteristics and to determine whether differences herein exist between the multiple sclerosis (MS), neoplasm, post-transplantation, and autoimmune disease subgroups. Reports of possible, probable, and definite PML according to the current diagnostic criteria were obtained by a systematic search of PubMed and the Dutch pharmacovigilance database. Demographic, epidemiologic, clinical, radiological, cerebrospinal fluid (CSF), and histopathological features were extracted from each report and differences were compared between the disease categories. In the 326 identified reports, PML onset occurred on average 29.5 months after drug introduction, varying from 14.2 to 37.8 months in the neoplasm and MS subgroups, respectively. The most common overall symptoms were motor weakness (48.6 %), cognitive deficits (43.2 %), dysarthria (26.3 %), and ataxia (24.1 %). The former two also constituted the most prevalent manifestations in each subgroup. Lesions were more often localized supratentorially (87.7 %) than infratentorially (27.4 %), especially in the frontal (64.1 %) and parietal lobes (46.6 %), and revealed enhancement in 27.6 % of cases, particularly in the MS (42.9 %) subgroup. Positive JC virus results in the first CSF sample were obtained in 63.5 %, while conversion after one or more negative outcomes occurred in 13.7 % of cases. 52.2 % of patients died, ranging from 12.0 to 83.3 % in the MS and neoplasm subgroups, respectively. In conclusion, despite the heterogeneous nature of the underlying diseases, motor weakness and cognitive changes were the two most common manifestations of drug-associated PML in all subgroups. The frontal and parietal lobes invariably constituted the predilection sites of drug-related PML lesions.

The Swedish MS registry – clinical support tool and scientific resource

The Swedish MS registry (SMSreg) is designed to assure quality health care for patients with multiple sclerosis (MS). It has been active since 2001 and web-based since 2004. It runs on government funding only and is used in all Swedish neurology departments. The SMSreg currently includes data on 14,500 of Sweden's estimated 17,500 prevalent patients with MS. One important function of SMSreg, to which participation is voluntary, is to serve as a tool for decision support and to provide an easy overview of the patient information needed at clinical visits. This is its core feature and explains why the majority of Swedish MS specialists contribute data. Another success factor for SMSreg is that entered data can be readily accessed, either through a query function into Excel format or through a set of predesigned tables and diagrams in which parameters can be selected. Recent development includes a portal allowing patients to view a summary of their registered data and to report a set of patient-reported outcomes. SMSreg data have been used in close to 100 published scientific reports. Current projects include an incidence cohort (EIMS), post-marketing cohorts of patients on novel disease-modifying drugs (IMSE), and a prevalence cohort (GEMS). As these studies combine physical sampling and questionnaire data with clinical documentation and possible linkage to other public registries, together they provide an excellent platform for integrated MS research.

CD49d is a disease progression biomarker and a potential target for immunotherapy in Duchenne muscular dystrophy

BACKGROUND

Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene. The immune inflammatory response also contributes to disease progression in DMD patients. In a previous study, we demonstrated higher levels of circulating CD49dhi and CD49ehi T cells in DMD patients compared to healthy control. DMD patients are clinically heterogeneous and the functional defect cannot be correlated with genotype. Therefore, it is important to be able to define reliable noninvasive biomarkers to better define the disease progression at the beginning of clinical trials.

RESULTS

We studied 75 DMD patients at different stages of their disease and observed that increased percentages of circulating CD4(+)CD49d(hi) and CD8(+)CD49d(hi) T lymphocytes were correlated with both severity and a more rapid progression of the disease. Moreover, T(+)CD49d(+) cells were also found in muscular inflammatory infiltrates. Functionally, T cells from severely affected patients exhibited higher transendothelial and fibronectin-driven migratory responses and increased adhesion to myotubes, when compared to control individuals. These responses could be blocked with an anti-CD49d monoclonal antibody.

CONCLUSION

CD49d can be used as a novel biomarker to stratify DMD patients by predicting disease progression for clinical trials. Moreover, anti-CD49d peptides or antibodies can be used as a therapeutic approach to decrease inflammation-mediated tissue damage in DMD.

Natalizumab in multiple sclerosis: discontinuation, progressive multifocal leukoencephalopathy and possible use in children

In the early 1990s, attention was drawn to the migration of immune cells into the central nervous system via the blood-brain barrier. The literature showed that lymphocytes binding to the endothelium were successfully inhibited by an antibody against α4β1 integrin. These biological findings resulted in the development of a humanized antibody to α4 integrin - natalizumab (NTZ) - to treat multiple sclerosis (MS). Here, we provide a systematic review and meta-analysis on the efficacy and safety of natalizumab, trying to answer the question whether its use may be recommended both in adult and in pediatric age groups as standard MS treatment. Our results highlight the improvement of clinical and radiological findings in treated patients (p < 0.005), confirming NTZ efficacy. Nevertheless, if NTZ is shown to be efficient, further studies should be performed to evaluate its safety and to target the MS profile that could benefit from this treatment.

Safety and efficacy of natalizumab in Belgian multiple sclerosis patients: subgroup analysis of the natalizumab observational program

Natalizumab (Tysabri(®)) is highly efficacious in controlling disease activity in relapsing multiple sclerosis (MS) patients. As it is one of the more recent therapies for MS, there remains a need for long-term safety and efficacy data of natalizumab in a clinical practice setting. The Tysabri observational program (TOP) is an open-label, multicenter, multinational, prospective observational study, aiming to recruit up to 6,000 patients with relapsing-remitting MS from Europe, Canada and Australia. The objectives of this study are to collect long-term safety and efficacy data on disease activity and disability progression. We report here the interim results of the 563 patients included in TOP between December 2007 and 2012 from Belgium. This patient cohort was older at baseline, had longer disease duration, higher neurological impairment, and a higher baseline annualized relapse rate, when compared to patients included in the pivotal phase III AFFIRM trial. Nevertheless, the efficacy of natalizumab was comparable. The annualized relapse rate on treatment was reduced by 90.70 % (p < 0.0001) with a cumulative probability of relapse of 26.87 % at 24 months. The cumulative probabilities of sustained disability improvement and progression at 24 months were 25.68 and 9.01 %, respectively. There were no new safety concerns over the follow-up period. Two cases of progressive multifocal leukoencephalopathy were diagnosed. Our results are consistent with other observational studies in the post-marketing setting.

Metabolic and safety issues for multiple sclerosis pharmacotherapy--opportunities for personalised medicine

INTRODUCTION

A number of disease-modifying therapies have become available to treat multiple sclerosis (MS) in recent years. As the effects of these medications are unpredictable and they are generally used for a number of years, the selection of the most appropriate disease-modifying agent must be based on the long-term efficacy and toxicity profile, thus strategies to personalise treatment to optimise responses may be potentially very useful.

AREAS COVERED

This review provides an overview of the efficacy and toxicity of disease-modifying agents used in MS and specifically discusses any metabolic side effects and advances in personalising the use of each of these agents. Medline and EMBASE were searched for any articles regarding the efficacy, toxicity and personalised use of the medicines discussed in this review.

EXPERT OPINION

Disease-modifying agents used to treat MS differ substantially in their efficacy and toxicity profile, but metabolic side effects appear to be limited to alemtuzumab, teriflunomide and IFN-β. Although personalised treatment strategies to assist in selection of the most appropriate disease-modifying agent for MS are limited, there is substantial potential to use genetic sub-studies of the many recent trials investigating disease-modifying agents to develop personalised treatment strategies.

Cerebrospinal fluid JC virus antibody index for diagnosis of natalizumab-associated progressive multifocal leukoencephalopathy

OBJECTIVE

Progressive multifocal leukoencephalopathy (PML), caused by JC virus (JCV), can occur in patients receiving natalizumab for multiple sclerosis (MS). JCV detection by quantitative polymerase chain reaction (qPCR) in cerebrospinal fluid (CSF), or brain biopsy, is required for probable or definite diagnosis of PML. However, in some patients only low levels of JCV DNA (<100 copies/ml) are present in CSF, making the diagnosis challenging. Our objective was to assess the complementary value of a CSF JCV antibody index (AIJCV ) in the diagnosis of natalizumab-associated PML.

METHODS

AIJCV was assessed in 37 cases of natalizumab-associated PML and 89 MS-patients treated with natalizumab without PML. Sera and CSF were tested in a capture enzyme-linked immunosorbent assay, using JCV-VP1 fused to glutathione S-transferase as antigen. Albumin levels and total immunoglobulin G concentration were determined by immunonephelometry, and the AIJCV was calculated as published.

RESULTS

Twenty-six of 37 (70%) patients with natalizumab-associated PML exhibited an AIJCV > 1.5, whereas this was seen in none of the controls (p < 0.0001). At time of the first positive qPCR for JCV DNA, 11 of 20 (55%) patients with natalizumab-associated PML had an AIJCV > 1.5. JCV DNA levels of <100 copies/ml were seen in 14 (70%) of these 20 patients, of whom 8 (57%) demonstrated an AIJCV > 1.5.

INTERPRETATION

Determination of the AIJCV could be an added tool in the diagnostic workup for PML and should be included in the case definition of natalizumab-associated PML.

Natalizumab: a review of its use in the management of relapsing-remitting multiple sclerosis

Natalizumab (Tysabri®) is a humanized monoclonal antibody against the α4 chain of integrins and was the first targeted therapy to be approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). Natalizumab acts as a selective adhesion molecule antagonist, which binds very late antigen (VLA)-4 and inhibits the translocation of activated VLA-4-expressing leukocytes across the blood-brain barrier into the CNS. In a pivotal phase III clinical trial, natalizumab 300 mg intravenously every 4 weeks for 2 years in adults with RRMS significantly reduced the annualized relapse rate and the risk of sustained progression of disability compared with placebo, as well as significantly increasing the proportion of relapse-free patients at 1 and 2 years. Natalizumab also significantly reduced the number of T2-hyperintense, gadolinium-enhancing and T1-hypointense lesions on magnetic resonance imaging, and significantly reduced the volume of T2-hyperintense and T1-hypointense lesions compared with placebo. Natalizumab recipients generally experienced improved health-related quality of life at 1-2 years. Natalizumab was generally well tolerated in pivotal trials. The only adverse events that were more frequent with natalizumab monotherapy than with placebo were fatigue and allergic reactions. The main safety and tolerability issue with natalizumab is the incidence of progressive multifocal leukoencephalopathy (PML). As long as the risk of PML is managed effectively, natalizumab is a valuable therapeutic option for adults with highly active relapsing forms of multiple sclerosis.

Changes to anti-JCV antibody levels in a Swedish national MS cohort

BACKGROUND

The anti-JC virus (JCV) antibody status has been introduced to stratify patients with multiple sclerosis (MS) for higher or lower risk of progressive multifocal leukoencephalopathy (PML).

OBJECTIVE

To assess the potential utility of anti-JCV antibody levels for earlier diagnosis or prediction of PML.

METHODS

An analytically validated antibody assay was used to determine serological status, normalised optical density values, and dilution titres for anti-JCV antibodies. The method was applied to stored sera of 1157 patients with MS including five cases of PML, all enrolled in the Swedish pharmacovigilance study for natalizumab (NAT). Anticytomegalovirus (CMV) and antivaricella-zoster (VZV) antibody levels served as controls.

RESULTS

Prior to treatment with NAT, anti-JCV antibody levels were stable in the anti-JCV positive patients. During therapy, a slight decrease in anti-JCV and anti-VZV antibody levels, but not anti-CMV antibody levels, was observed. All five patients who developed PML showed a mild to moderate increase in anti-JCV antibody levels at time of PML diagnosis; pre-PML samples suggested that this increase might start already prior to diagnosis of PML.

CONCLUSIONS

Treatment initiation with NAT may lead to a slight decrease in anti-JCV and anti-VZV antibody levels, suggestive of a mild suppressive effect of NAT on antibody levels. Our findings in five cases of PML demonstrate that the onset of PML can be accompanied by increasing anti-JCV antibodies in serum. Monitoring of anti-JCV antibody levels could potentially be used as a tool for prediction or earlier diagnosis of PML during NAT treatment for MS. Further studies are warranted.

Incidence of multiple sclerosis among European Economic Area populations, 1985-2009: the framework for monitoring

Background

A debate surrounding multiple sclerosis epidemiology has centred on time-related incidence increases and the need of monitoring. The purpose of this study is to reassess multiple sclerosis incidence in the European Economic Area.

Methods

We conducted a systematic review of literature from 1965 onwards and integrated elements of original research, including requested or completed data by surveys authors and specific analyses.

Results

The review of 5323 documents yielded ten studies for age- and sex-specific analyses, and 21 studies for time-trend analysis of single data sets. After 1985, the incidence of multiple sclerosis ranged from 1.12 to 6.96 per 100,000 population, was higher in females, tripled with latitude, and doubled with study midpoint year. The north registered increasing trends from the 1960s and 1970s, with a historic drop in the Faroe Islands, and fairly stable data in the period 1980-2000; incidence rose in Italian and French populations in the period 1970-2000, in Evros (Greece) in the 1980s, and in the French West Indies in around 2000.

Conclusions

We conclude that the increase in multiple sclerosis incidence is only apparent, and that it is not specific to women. Monitoring of multiple sclerosis incidence might be appropriate for the European Economic Area.

Best practice in the use of natalizumab in multiple sclerosis

Natalizumab is approved for the treatment of patients with relapsing-remitting multiple sclerosis who have failed first-line treatment with traditional disease-modifying therapies or who have highly active disease. The drug has proved highly effective, both in a clinical trial setting and in clinical practice, with marked reductions in the rate of clinical relapses and slowed disease progression. These clinical outcomes are mirrored by a marked reduction in disease activity as evidenced by magnetic resonance imaging of the brain. However, natalizumab treatment has been associated with a risk of progressive multifocal leukoencephalopathy (PML), a potentially fatal condition caused by JC virus (JCV) activation. When this condition was detected in a clinical trial shortly after approval, the drug was immediately and voluntarily withdrawn from the market. As a condition of its reinstatement, stringent pharmacovigilance measures and a risk management plan were enforced. The recent availability of a two-step enzyme-linked immunosorbent assay (ELISA) test for the presence of anti-JCV antibodies (free testing is available in a central laboratory for registered centers), along with an ever-improving understanding of other risk factors such as prior immunosuppressant use and duration of treatment, allow an increasingly refined stratification of the risk of PML. This improved stratification of risk can help guide decisions about treatment. This review will also deal with other topics of relevance to clinical practice such as the development of antinatalizumab antibodies and their negative implications in terms of hypersensitivity reactions and loss of efficacy, withdrawal of treatment, and compassionate pediatric use.

Natalizumab treatment of multiple sclerosis in Spain: results of an extensive observational study

Natalizumab has been shown to be effective in pivotal clinical trials in multiple sclerosis; however, the patients in whom treatment is indicated in clinical practice have a different clinical profile from those included in the clinical trials. The aim of this study is therefore to collect data on natalizumab use in everyday clinical practice in Spain. The 86 participating centers throughout Spain submitted data on disease characteristics at baseline and after treatment. Valid data were available for 1,364 patients (69.3% women, 86.9% with relapsing–remitting disease).

Characteristics of progressive multifocal leukoencephalopathy clarified through internet-assisted laboratory surveillance in Japan

Background

Progressive multifocal leukoencephalopathy (PML), a rare but fatal demyelinating disease caused by JC virus (JCV), occurs mainly in immunocompromised patients. As PML develops in individuals with various underlying disorders sporadically and infrequently, a nationwide survey of PML is difficult. This study was conducted to elucidate the characteristics of PML in Japan through an internet-assisted laboratory surveillance program.

Methods

A diagnostic support system for PML was established using a real-time PCR assay of JCV DNA in cerebrospinal fluid (CSF), and requests for testing were received from clinicians via specialized websites. Medical histories of patients were collected through standardized questionnaires, and a database of CSF JCV loads and clinical information was created and analyzed.

Results

For 4 years from April 2007 to March 2011, CSF specimens from 419 patients were tested. Forty-eight individuals were found positive for JCV DNA in their CSF and were diagnosed with PML. PML primarily occurred not only in HIV-positive patients (33.3%) but also in patients with hematologic disorders after receiving stem cell transplantation, chemotherapy, and/or immunosuppressive treatment (39.6%). The frequencies of PML cases among the subjects in these two categories were 20.3% and 23.5%, respectively. Although no significant features were observed with respect to CSF JCV loads in PML patients with an HIV infection or hematologic disorder, males were predominant in both groups (100% and 89.5%, respectively). The proportion of PML cases with autoimmune disorders (6.3%) or solid-organ transplants (2.1%) was smaller than those with HIV infection or hematologic disorders, probably due to the limited availability of therapeutic monoclonal antibodies and transplantation from brain dead donors.

Conclusions

The results suggest that the internet-assisted laboratory surveillance program might be a useful strategy for collecting precise real-time information on PML on a national level. The current database provides important background information for the diagnosis and treatment of patients with risk factors for PML.

Characterization of anti-natalizumab antibodies in multiple sclerosis patients

BACKGROUND

A small proportion of multiple sclerosis (MS) patients treated with natalizumab develop anti-drug antibodies.

OBJECTIVE

The objective of this paper is to characterize the anti-natalizumab antibody response and to investigate differences between persistently and transiently antibody-positive patients.

METHODS

Screening for anti-natalizumab antibodies was performed using a standardized bridging ELISA. Antibody-positive samples were further analyzed for IgM and IgG1-4 antibodies using ELISA and ImmunoCAP®.

RESULTS

Anti-natalizumab antibodies developed in 57 of 1379 (4.1%) treated patients after a median treatment duration of three months. Of the positive patients, 20 (35%) patients reverted to negative, 19 (33%) patients were confirmed persistently positive and 18 (32%) patients were unconfirmed positive. Significantly higher anti-natalizumab antibody levels were detected in persistently compared to transiently positive patients. A cutoff value predicting persistence of antibodies could be determined with a sensitivity of 0.84 and a specificity of 0.80. IgM and IgG4 antibody levels were significantly higher in persistently compared to transiently positive patients, and IgG1, IgG2 and IgG4 increased significantly over time.

CONCLUSIONS

The level of total anti-natalizumab antibodies in a first positive sample can be used to predict patients at risk for persisting antibody positivity. However, neither IgM nor IgG1-4 antibodies could be used to discriminate between transiently and persistently positive patients.

Concordance of preclinical and clinical pharmacology and toxicology of therapeutic monoclonal antibodies and fusion proteins: cell surface targets

Monoclonal antibodies (mAbs) and fusion proteins directed towards cell surface targets make an important contribution to the treatment of disease. The purpose of this review was to correlate the clinical and preclinical data on the 15 currently approved mAbs and fusion proteins targeted to the cell surface. The principal sources used to gather data were: the peer reviewed Literature; European Medicines Agency 'Scientific Discussions'; and the US Food and Drug Administration 'Pharmacology/Toxicology Reviews' and package inserts (United States Prescribing Information). Data on the 15 approved biopharmaceuticals were included: abatacept; abciximab; alefacept; alemtuzumab; basiliximab; cetuximab; daclizumab; efalizumab; ipilimumab; muromonab; natalizumab; panitumumab; rituximab; tocilizumab; and trastuzumab. For statistical analysis of concordance, data from these 15 were combined with data on the approved mAbs and fusion proteins directed towards soluble targets. Good concordance with human pharmacodynamics was found for mice receiving surrogates or non-human primates (NHPs) receiving the human pharmaceutical. In contrast, there was poor concordance for human pharmacodynamics in genetically deficient mice and for human adverse effects in all three test systems. No evidence that NHPs have superior predictive value was found.

Impact of natalizumab on cognitive performances and fatigue in relapsing multiple sclerosis: a prospective, open-label, two years observational study

BACKGROUND AND OBJECTIVES

Natalizumab reduces the relapse rate and magnetic resonance imaging activity in patients with Relapsing-Remitting Multiple Sclerosis (RRMS). So far the influence of natalizumab on cognitive functions and fatigue in MS remains uncertain. The aim of this prospective, open-label, observational study was to evaluate the possible effects of natalizumab on cognition and fatigue measures in RRMS patients treated for up to two years.

METHODS

Cognitive performances were examined by the Rao's Brief Repeatable Battery (BRB), the Stroop test (ST) and the Cognitive Impairment Index (CII), every 12 months. Patients who failed in at least 3 tests of the BRB and the ST were classified as cognitively impaired (CI). Fatigue Severity Scale (FSS) was administered every 12 months to assess patient's self-reported fatigue. One hundred and 53 patients completed 1 and 2 year-natalizumab treatment, respectively.

RESULTS

After 1 year of treatment the percentage of CI patients decreased from 29% (29/100) at baseline to 19% (19/100) (p = 0.031) and the mean baseline values of CII (13.52±6.85) and FSS (4.01±1.63) scores were significantly reduced (10.48±7.12, p<0.0001 and 3.61±1.56, p = 0.008). These significant effects were confirmed in the subgroup of patients treated up to two years.

CONCLUSIONS

These results demonstrate that a short-term NTZ treatment may significantly improve cognitive performances and fatigue in RRMS patients.

Fetal and Neonatal Illnesses Caused or Influenced by Maternal Transplacental IgG and/or Therapeutic Antibodies Applied During Pregnancy

The human fetus is protected by the mother’s antibodies. At the end of the pregnancy, the concentration of maternal antibodies is higher in the cord blood, than in the maternal circulation. Simultaneously, the immune system of the fetus begins to work and from the second trimester, fetal IgM is produced by the fetal immune system specific to microorganisms and antigens passing the maternal-fetal barrier. The same time the fetal immune system has to cope and develop tolerance and T_REG cells to the maternal microchimeric cells, latent virus-carrier maternal cells and microorganisms transported through the maternal-fetal barrier.

The maternal phenotypic inheritance may hide risks for the newborn, too. Antibody mediated enhancement results in dengue shock syndrome in the first 8 month of age of the baby.

A series of pathologic maternal antibodies may elicit neonatal illnesses upon birth usually recovering during the first months of the life of the offspring. Certain antibodies, however, may impair the fetal or neonatal tissues or organs resulting prolonged recovery or initiating prolonged pathological processes of the children.

The importance of maternal anti-idiotypic antibodies are believed to prime the fetal immune system with epitopes of etiologic agents infected the mother during her whole life before pregnancy and delivery.

The chemotherapeutical and biological substances used for the therapy of the mother will be transcytosed into the fetal body during the last two trimesters of pregnancy. The long series of the therapeutic monoclonal antibodies and conjugates has not been tested systematically yet. The available data are summarised in this chapter.

The innate immunity plays an important role in fetal defence. The concentration of interferon is relative high in the placenta. This is probably one reason, why the therapeutic interferon treatment of the mother does not impair the fetal development.

Effect of natalizumab on clinical and radiological disease activity in a French cohort of patients with relapsing-remitting multiple sclerosis

"Disease activity free" in relapsing-remitting multiple sclerosis (RRMS) is a new concept introduced by the results of the AFFIRM study. Our objective was to analyze the clinical and radiological efficacy of natalizumab treatment in actual clinical practice and compare it with the post hoc analysis of the AFFIRM study. All patients with RRMS who began treatment with natalizumab at our two French MS centres between April 2007 and May 2008 were included and followed-up for at least 2 years. No measurable disease activity ("disease activity free") was defined as no activity on clinical measures (no relapses and no sustained disability progression) and radiological measures (no gadolinium-enhancing lesions and no new T2-hyperintense lesions on cerebral MRI). A total of 193 patients were included. Natalizumab was discontinued in 25.9% of cases before the completion of 2 years of treatment. In our cohort, we observed patients with more severe disease than in the AFFIRM study. The proportion of patients remaining free of clinical activity during 2 years of treatment was lower than in the AFFIRM study (37.8% vs. 64.3%). The proportion of patients remaining free of radiological activity during 2 years of treatment was higher than in the AFFIRM study (68.9% vs. 57.7%), while the proportion of patients remaining free of disease activity during 2 years of treatment was comparable to the AFFIRM study (33.3% vs. 36.7%). Natalizumab seems to be as effective in a real-life setting as in pivotal and post hoc studies. The confirmation of such benefits is important because of the progressive multifocal leukoencephalopathy risk.

Natalizumab treatment for multiple sclerosis: updated recommendations for patient selection and monitoring

Natalizumab, a highly specific α4-integrin antagonist, is approved for treatment of patients with active relapsing-remitting multiple sclerosis (RRMS). It is generally recommended for individuals who have not responded to a currently available first-line disease-modifying therapy or who have very active disease. The expected benefits of natalizumab treatment have to be weighed against risks, especially the rare but serious adverse event of progressive multifocal leukoencephalopathy. In this Review, we revisit and update previous recommendations on natalizumab for treatment of patients with RRMS, based on additional long-term follow-up of clinical studies and post-marketing observations, including appropriate patient selection and management recommendations.

Development of oral immunomodulatory agents in the management of multiple sclerosis

The emergence of oral disease-modifying therapies in multiple sclerosis (MS) will have a significant impact on the evolving scenario of immunomodulatory treatments in MS where current therapies are all injectable. Reducing relapses in trials translates for individuals with MS into a therapeutic aim of stopping future events. Thus the possible absence of any perceived benefits to the individual together with the long disease course, variable outcome, and a younger age group affected in MS makes side effects the major issue. The use of disease-modifying therapies as a whole needs to be placed in the context of a widening therapeutic indication where the use of these therapies is being justified at an increasingly early stage and in pre-MS syndromes such as clinically isolated and radiologically isolated syndromes where no fixed disability is likely to have accumulated. The five oral therapies discussed (cladribine, fingolimod, laquinimod, BG-12, and teriflunomide) have just completed Phase III studies and some have just been licensed. New oral drugs for MS need to be placed within this evolving marketplace where ease of delivery together with efficacy and side effects needs to be balanced against the known issues but also the known long-term safety of standard injectables.

Occurrence of antibodies against natalizumab in relapsing multiple sclerosis patients treated with natalizumab

BACKGROUND

In the clinical trials about 9% of natalizumab treated multiple sclerosis (MS) patients generated anti-natalizumab antibodies, of which 6% were persistent and 3% transient. The occurrence of antibodies reduced serum levels of natalizumab, decreased bio-efficacy, and abrogated the therapeutic efficacy.

OBJECTIVE

The objective was to assess the frequency of anti-natalizumab antibodies in an unselected cohort of patients from four different countries.

METHODS

We measured anti-natalizumab antibodies in a large cohort of 4881 unselected patients from four MS centres that systematically measured antibodies in patients treated with natalizumab. We applied the same ELISA assay developed by Biogen Idec and used in the pivotal trials of natalizumab.

RESULTS

Antibodies occurred in 4.5% (95% confidence interval, CI: 4.0-5.1%) of the patients, and were persistent in 3.5% (95% CI: 3.0-4.0%) and transient in 1.0% (95% CI: 0.7-1.3%) of the patients. The frequencies of permanently antibody positive patients did not show statistically significant differences between the four centres, whereas the frequencies of transiently antibody positive patients showed some variations.

CONCLUSION

The frequencies of antibodies appeared to be of the same magnitude in the four centres, but might be less than in the pivotal studies of natalizumab.