118 Sustained reduction of disability and cognitive decline with long-term siponimod in EXPAND active SPMS patients

Background

In the EXPAND study, patients with active SPMS (aSPMS) demonstrated a reduced risk of 3/6-month confirmed disability progression (3m/6m CDP) and risk of decline in cognitive processing speed (CPS, 6-month confirmed cognition worsening of ≥4-point on Symbol Digit Modalities Test [6mCCW]) versus placebo.

Objectives

Assess long-term efficacy and safety of siponimod in patients with aSPMS.

Methods

In aSPMS patients who entered the EXPAND Extension, time to 3m/6mCDP, 6mCCW, and annu- alized relapse rate (ARR) were assessed for the Continuous (siponimod in Core and Extension) and Switch (placebo in Core and open-label siponimod in Core/Extension) groups.

Results

Risk of 6mCDP was reduced by 29% (0.71 [0.57–0.90]; p=0.0044) for Continuous versus Switch group, corresponding to approximately 70% delay in time to 6mCDP. The risk of 6mCCW for Continuous versus Switch group was reduced by 33% (0.67 [0.53–0.86]); p=0.0018), corresponding to approximately 70% delay in time to 6mCCW. A significant reduction in ARR for the Continuous versus Switch groups was observed in patients with or without active disease.

Conclusions

Long-term data analyses showed that siponimod effects on disability, cognitive processing speed, and relapse outcomes in patients with active SPMS are sustained up to 5 years, and highlight the value of early treatment initiation.

teresa.sawtell@novartis.com

114 Effect of siponimod on cognitive processing speed in SPMS patients with active and non-active disease

Background

Siponimod significantly reduced the relative risk of 3-month (m) confirmed disability progression (CDP) by 21% and 6mCDP by 26% versus placebo in the EXPAND core study and showed significant benefits on cognitive processing speed (CPS) using the Symbol Digit Modalities Test (SDMT).

Objectives

To evaluate the effect of siponimod on CPS in active (aSPMS) and non-active (naSPMS) patients from EXPAND core study.

Methods

This subgroup analysis included aSPMS patients (siponimod, n=516; placebo, n=263) and naSPMS patients (siponimod, n=557; placebo, n=270). Change in SDMT score; time to 6m confirmed ≥4-points cognitive worsening/improvement (6mCW/6mCI) on SDMT and the proportion of patients with worsened, stable and improved SDMT scores at M24 were analysed.

Results

Change in SDMT (95% Cl) versus placebo from baseline to M24 in aSPMS and naSPMS groups was

2.34 (0.66; 4.02) and 2.44 (0.67; 4.22), respectively, consistent with overall EXPAND core population. In aSPMS patients, siponimod reduced risk of 6mCW by 27% (p=0.06) and improved chances of 6mCI by 62% (p=0.007) versus placebo. Corresponding values in the naSPMS group were: 6mCW, 24% (p=ns) and 6mCI, 19% (p=ns).

Conclusions

Siponimod was associated with relevant benefits in CPS as measured by change in SDMT in patients with active and non-active SPMS.

teresa

sawtell@novartis.com

82

115 Impact of siponimod on myelination across SPMS subgroups: post-hoc analysis from EXPAND MRI substudy

Background

Changes in magnetization transfer ratio (MTR) are a marker of changes in myelin density and brain tissue integrity. Siponimod improved lesional MTR recovery in the overall EXPAND secondary progressive multiple sclerosis (SPMS) population.

Objectives

Investigate the effect of siponimod on MTR changes in SPMS subgroups.

Methods

This prospective sub-study assessed the effect of siponimod versus placebo on median nor- malized MTR (nMTR) in normal appearing brain tissue (NABT), cortical Grey Matter (cGM) and normal appearing white matter (NAWM). Subgroups were defined by: disease history, severity and duration, EDSS score, Symbol Digit Modalities Test score, and inflammatory disease activity.

Results

There was an attenuation in median nMTR decrease versus placebo across all subgroups (all p<0.05 except EDSS≥6 subgroup, p=0.064). In the active SPMS subgroup, siponimod attenuated median nMTR decrease across NABT, cGM and NAWM by 91–109% (p<0.01 all); and in the non-active SPMS subgroup by 170– 198% (p=0.0151 for NAWM, p>0.05 for NABT, cGM).

Conclusions

Over 24 months, siponimod attenuated the decrease in median nMTR in brain tissues across patient subgroups characterized by disease activity and severity, with most pronounced effects in NAWM. This supports preclinical studies, showing beneficial CNS effects on myelination.

teresa.sawtell@novartis.com

Continuous daily assessment of multiple sclerosis disability using remote step count monitoring

Disability measures in multiple sclerosis (MS) rely heavily on ambulatory function, and current metrics fail to capture potentially important variability in walking behavior. We sought to determine whether remote step count monitoring using a consumer-friendly accelerometer (Fitbit Flex) can enhance MS disability assessment. 99 adults with relapsing or progressive MS able to walk ≥2-min were prospectively recruited. At 4 weeks, study retention was 97% and median Fitbit use was 97% of days. Substudy validation resulted in high interclass correlations between Fitbit, ActiGraph and manual step count tally during a 2-minute walk test, and between Fitbit and ActiGraph (ICC = 0.76) during 7-day home monitoring. Over 4 weeks of continuous monitoring, daily steps were lower in progressive versus relapsing MS (mean difference 2546 steps, p < 0.01). Lower average daily step count was associated with greater disability on the Expanded Disability Status Scale (EDSS) (p < 0.001). Within each EDSS category, substantial variability in step count was apparent (i.e., EDSS = 6.0 range 1097-7152). Step count demonstrated moderate-strong correlations with other walking measures. Lower average daily step count is associated with greater MS disability and captures important variability in real-world walking activity otherwise masked by standard disability scales, including the EDSS. These results support remote step count monitoring as an exploratory outcome in MS trials.

Vitamin D in African Americans with multiple sclerosis

OBJECTIVE

To evaluate whether vitamin D is associated with multiple sclerosis (MS) status and disease severity in African Americans.

METHODS

Serum 25-hydroxyvitamin D was compared in a cross-sectional sample of 339 African Americans with MS and 342 African American controls. Correlations between disease severity (Multiple Sclerosis Severity Score [MSSS]) and 25-hydroxyvitamin D levels were sought.

RESULTS

A total of 71% of controls and 77% of patients with MS were vitamin D deficient (<50 nmol/L; <20 ng/mL), and 93% of controls and 94% of patients with MS were vitamin D insufficient (<75 nmol/L; <30 ng/mL). Median unadjusted (29.7 vs 36.6 nmol/L, p = 0.0001) and deseasonalized (p = 0.0013) 25-hydroxyvitamin D levels were lower in the MS group. Multivariable analysis revealed that differences in latitude and ultraviolet index accounted for much of this association. The median (interquartile range) MSSS was 6.1 (4.8-8.1). There was no apparent association between the MSSS and vitamin D status. A greater proportion of European genetic ancestry, a measure of genetic admixture, was positively correlated with 25-hydroxyvitamin D (p = 0.007).

CONCLUSIONS

Levels of 25-hydroxyvitamin D were lower in African Americans with MS than controls, an observation primarily explained by differences in climate and geography. There was no apparent association between vitamin D status and disease severity. These results are consistent with observations in other populations that lower 25-hydroxyvitamin D is associated with having MS, but also highlight the importance of climate and ancestry in determining vitamin D status.

Asymptomatic spinal cord lesions predict disease progression in radiologically isolated syndrome

BACKGROUND

Technological advancements in neuroimaging and the increased use of these diagnostic modalities are responsible for the discovery of incidentally identified anomalies within the CNS. In addition to the identification of unanticipated brain MRI abnormalities suggestive of demyelinating disease in patients undergoing neuroimaging for a medical reason other than evaluation for multiple sclerosis (MS), asymptomatic spinal cord lesions are periodically identified.

OBJECTIVE

To determine if asymptomatic spinal cord lesions are associated with clinical progression in subjects with radiologically isolated syndrome (RIS).

METHODS

A retrospective review of RIS cases at the University of California, San Francisco Multiple Sclerosis Center was performed. The presence of asymptomatic cervical spinal cord MRI lesions was analyzed as a potential predictor for clinical progression.

RESULTS

Twenty-five of 71 subjects with RIS possessed findings within the cervical spine that were highly suggestive of demyelinating disease. Of these subjects, 21 (84%) progressed clinically to clinically isolated syndrome (n = 19) or primary progressive multiple sclerosis (n = 2) over a median time of 1.6 years from the date of RIS identification (interquartile range 0.8-3.8). The sensitivity, specificity, and positive predictive value of an asymptomatic spinal cord lesion for subsequent development of either a first demyelinating attack or primary progressive MS were 87.5%, 91.5%, and 84%, respectively. The odds ratio of clinical progression was 75.3 (95% confidence interval 16.1-350.0, p < 0.0001). This association remained significant after adjusting for potential confounders.

CONCLUSION

These findings suggest that the presence of asymptomatic spinal cord lesions place subjects with RIS at substantial risk for clinical conversion to either an acute or progressive event, a risk that is independent of brain lesions on MRI.

Distinctive retinal nerve fibre layer and vascular changes in neuromyelitis optica following optic neuritis

PATIENTS AND METHODS

This is a cross sectional study comparing the retinal features of optic neuritis (ON) between 20 multiple sclerosis (MS) and 16 neuromyelitis optica (NMO) patients with a history of ON (visual acuity at time of attack >20/100) matched for age and gender using optical coherence tomography (OCT) and fundoscopy.

RESULTS

Compared with MS, NMO patients often had: (1) vascular changes, including attenuation of the peripapillary vascular tree (3/40 MS eyes, 22/32 NMO eyes; p = 0.001) and focal arteriolar narrowing (0/40 MS eyes and 9/32 NMO eyes; p<0.0001), (2) a lower average nerve fibre layer (NFL) thickness (59.2 microm compared with 82.0 microm in MS; p = 0.004) and (3) nearly twice the NFL thinning after controlling for final visual acuity (32.1 vs 17.6 microm; p = 0.004). Patients with NMO had more severe and diffuse axonal injury of the NFL compared with MS.

CONCLUSION

These NFL and fundoscopic findings suggest that some of the injury seen in NMO may be vascularly mediated. These inner retinal vascular changes are reminiscent of blood vessel wall thickening previously reported in the optic nerve and spinal cord at autopsy. If the retinal changes share a common pathology to those in the spinal cord and optic nerve, these observations suggest that vascular changes may be detectable during life.

Genotype-Phenotype correlations in multiple sclerosis: HLA genes influence disease severity inferred by 1HMR spectroscopy and MRI measures

Genetic susceptibility to multiple sclerosis (MS) is associated with the human leukocyte antigen (HLA) DRB1*1501 allele. Here we show a clear association between DRB1*1501 carrier status and four domains of disease severity in an investigation of genotype-phenotype associations in 505 robust, clinically well characterized MS patients evaluated cross-sectionally: (i) a reduction in the N-acetyl-aspartate (NAA) concentration within normal appearing white matter (NAWM) via (1)HMR spectroscopy (P = 0.025), (ii) an increase in the volume of white matter (WM) lesions utilizing conventional anatomical MRI techniques (1,127 mm(3); P = 0.031), (iii) a reduction in normalized brain parenchymal volume (nBPV) (P = 0.023), and (iv) impairments in cognitive function as measured by the Paced Auditory Serial Addition Test (PASAT-3) performance (Mean Z Score: DRB1*1501+: 0.110 versus DRB1*1501-: 0.048; P = 0.004). In addition, DRB1*1501+ patients had significantly more women (74% versus 63%; P = 0.009) and a younger mean age at disease onset (32.4 years versus 34.3 years; P = 0.025). Our findings suggest that DRB1*1501 increases disease severity in MS by facilitating the development of more T2-foci, thereby increasing the potential for irreversible axonal compromise and subsequent neuronal degeneration, as suggested by the reduction of NAA concentrations in NAWM, ultimately leading to a decline in brain volume. These structural aberrations may explain the significant differences in cognitive performance observed between DRB1*1501 groups. The overall goal of a deep phenotypic approach to MS is to develop an array of meaningful biomarkers to monitor the course of the disease, predict future disease behaviour, determine when treatment is necessary, and perhaps to more effectively recommend an available therapeutic intervention.

Multifactor dimensionality reduction reveals gene-gene interactions associated with multiple sclerosis susceptibility in African Americans

Multiple sclerosis (MS) is a common disease of the central nervous system characterized by inflammation, myelin loss, gliosis, varying degrees of axonal pathology, and progressive neurological dysfunction. Multiple sclerosis exhibits many of the characteristics that distinguish complex genetic disorders including polygenic inheritance and environmental exposure risks. Here, we used a highly efficient multilocus genotyping assay representing variation in 34 genes associated with inflammatory pathways to explore gene-gene interactions and disease susceptibility in a well-characterized African-American case-control MS data set. We applied the multifactor dimensionality reduction (MDR) test to detect epistasis, and identified single-IL4R(Q576R)- and three-IL4R(Q576R), IL5RA(-80), CD14(-260)- locus association models that predict MS risk with 75-76% accuracy (P<0.01). These results demonstrate the importance of exploring both main effects and gene-gene interactions in the study of complex diseases.

An open label study of the effects of rituximab in neuromyelitis optica

Eight patients with worsening neuromyelitis optica were treated with rituximab to achieve B cell depletion. Treatment was well tolerated. Six of eight patients were relapse free and median attack rate declined from 2.6 attacks/patient/year to 0 attacks/patient/year (p = 0.0078). Seven of eight patients experienced substantial recovery of neurologic function over 1 year of average follow-up. The pretreatment median Expanded Disability Status Scale score was 7.5, and at follow-up examination was 5.5 (p = 0.013).

Characterizing the mechanisms of progression in multiple sclerosis: evidence and new hypotheses for future directions

Major advancements have been achieved in our ability to diagnose multiple sclerosis (MS) and to commence treatment intervention with agents that can favorably affect the disease course. Although MS exacerbations and the emergence of disability constitute the more conspicuous aspects of the disease process, evidence has confirmed that most of the disease occurs on a constitutive and occult basis. Disease-modifying therapies appear to be modest in the magnitude of their treatment effects, particularly in the progressive stage of the disease. Therapeutic strategies currently used for MS primarily target the inflammatory cascade. Several potential mechanisms appear to be involved in the progression of MS. Characterizing these mechanisms will result in a better understanding of the various forms of the disorder and how to effectively treat its clinical manifestations. It is our objective within this 2-part series on progression in MS to offer both evidence-based observations and hypothesis-driven expert perspectives on what constitutes the cause of progression in MS. We have chosen areas of inquiry that appear to have been most productive in helping us to better conceptualize the landscape of what MS looks like pathologically, immunologically, neuroscientifically, radiographically, and genetically. We have attempted to advance hypotheses focused on a deeper understanding of what contributes to the progression of this illness and to illustrate new technical capabilities that are catalyzing novel research initiatives targeted at achieving a more complete understanding of progression in MS.

Clinical characteristics of African Americans vs Caucasian Americans with multiple sclerosis

BACKGROUND

African American (AA) individuals are thought to develop multiple sclerosis (MS) less frequently than Caucasian American (CA) individuals.

OBJECTIVE

To compare the clinical characteristics of AA and CA patients with MS.

METHODS

The clinical features of MS were compared in a large retrospective cohort of AA (n = 375) and CA (n = 427) subjects.

RESULTS

The proportion of women to men was similar in AA and CA subjects (81% [AA] vs 77% [CA]; p = 0.122). There were no differences in the proportions of subjects with relapsing-remitting, secondary progressive, primary progressive, and progressive relapsing MS. The median time to diagnosis was 1 year after symptom onset in AA subjects and 2 years after symptom onset in CA subjects (p = 0.0013). The age at onset was approximately 2.5 years later in AA than CA subjects (33.7 vs 31.1 years; p = 0.0001). AA subjects presented with multisite signs and symptoms at disease onset more often than CA subjects (p = 0.018). Clinical involvement restricted to the optic nerves and spinal cord (opticospinal MS) occurred in 16.8% of AA patients compared with 7.9% of CA patients (p < 0.001). Transverse myelitis also occurred more frequently in AA subjects (28 vs 18%; p = 0.001). Survival analysis revealed that AA subjects were at higher risk for development of ambulatory disability than CA subjects. After adjusting for baseline variations and differences in therapeutic interventions, AAs were at 1.67-fold greater risk for requiring a cane to ambulate than CA patients (p < 0.001). There was a trend suggesting that AAs were also at greater risk for development of wheelchair dependency (p = 0.099). Adjusted Cox proportional hazard models showed that this effect was in part attributable to the older age at onset in AAs (p < 0.001).

CONCLUSIONS

Compared with multiple sclerosis (MS) in Caucasian Americans, African American patients with MS have a greater likelihood of developing opticospinal MS and transverse myelitis and have a more aggressive disease course.