Time course of clinical and neuroradiological effects of delayed-release dimethyl fumarate in multiple sclerosis

BACKGROUND AND PURPOSE

Delayed-release dimethyl fumarate (DMF, also known as gastro-resistant DMF), demonstrated efficacy and safety in relapsing-remitting multiple sclerosis in the 2-year, randomized, placebo-controlled, phase 3 DEFINE and CONFIRM trials. A post hoc analysis of integrated data from DEFINE and CONFIRM was conducted to determine the temporal profile of the clinical and neuroradiological effects of DMF.

METHODS

Eligible patients were randomized to receive placebo, DMF 240 mg twice (BID) or three times (TID) daily or glatiramer acetate (GA; reference comparator; CONFIRM only) for up to 96 weeks. Patients in the GA group were excluded from this analysis.

RESULTS

A total of 2301 patients were randomized and received treatment with placebo (n = 771) or DMF BID (n = 769) or TID (n = 761). DMF significantly reduced the annualized relapse rate beginning in weeks 0-12 (BID, P = 0.0159; TID, P = 0.0314); the proportion of patients relapsed beginning at week 10 (BID, P = 0.0427) and week 12 (TID, P = 0.0451); and the proportion of patients with 12-week confirmed disability progression beginning at week 62 (BID, P = 0.0454) and week 72 (TID, P = 0.0399), compared with placebo. These effects were sustained throughout the 2-year study period. DMF significantly reduced the odds of having a higher number of gadolinium-enhancing lesions by 88% (BID) and 75% (TID) and the mean number of new or enlarging T2 lesions by 72% (BID) and 67% (TID), from the first post-baseline magnetic resonance imaging assessment at 24 weeks (all P < 0.0001 versus placebo).

CONCLUSIONS

In phase 3 clinical trials, DMF demonstrated rapid and sustained clinical and neuroradiological efficacy in relapsing-remitting multiple sclerosis.

Chromosomal ampC mutations in cefpodoxime-resistant, ESBL-negative uropathogenic Escherichia coli

AmpC β-lactamase is an enzyme commonly produced by Escherichia coli that causes resistance to cephalosporins and penicillins. Enzyme production is controlled by the strength of the promoter encoded by the chromosomal ampC gene, with the level of production affected by the presence of certain mutations in this region. This study sets out to determine the prevalence of ampC promoter mutations present in a group of uropathogenic E. coli strains. A total of 50 clinical strains of E. coli were collected from urine samples between June 2011 and November 2011. Strains were investigated for the presence of mutations in the chromosomal ampC promoter region by amplification and sequencing of a 271 bp product. The presence of ampC-carrying plasmids derived from other species was also determined, to exclude these from further analysis. ampC-carrying plasmids were found in 10 of the 50 strains, all of which were of the CIT-type. Analysis of the chromosomal ampC promoter region in the 40 remaining strains showed mutations at 16 different positions, with 18 different genotype patterns detected overall. The most common ampC chromosomal mutation, present in 25 of 40 strains, was a T --> A transition at position -32. This mutation has been shown by others to increase enzyme production by up to 46-fold. Altogether, three separate mutations (-32, -42 and -13ins) were present in 90% of the 40 non-plasmid strains, indicating a strong association with the resistance observed. It appears, therefore, that the majority of AmpC-mediated resistance in E. coli can be accounted for by just three point mutations in the chromosome.

Effect of peginterferon beta-1a on MRI measures and achieving no evidence of disease activity: results from a randomized controlled trial in relapsing-remitting multiple sclerosis

Background

Subcutaneous peginterferon beta-1a provided clinical benefits at Year 1 (placebo-controlled period) of the 2-Year Phase 3 ADVANCE study in relapsing-remitting multiple sclerosis (RRMS). Here we report the effect of peginterferon beta-1a on brain magnetic resonance imaging (MRI) lesions, and no evidence of disease activity (NEDA; absence of clinical [relapses and 12-week confirmed disability progression] and MRI [gadolinium-enhancing, and new or newly-enlarging T2 hyperintense lesions] disease activity) during Year 1.

Methods

RRMS patients (18–65 years; Expanded Disability Status Scale score ≤5) were randomized to double-blind placebo or peginterferon beta-1a 125 μg every 2 or 4 weeks. Sensitivity analyses of last observation carried forward and composite disease activity (using minimal MRI allowance definitions) were conducted.

Results

1512 patients were randomized and dosed (placebo n = 500; peginterferon beta-1a every 2 [n = 512] or 4 [n = 500] weeks). Every 2 week dosing significantly reduced, versus placebo and every 4 week dosing, the number of new or newly-enlarging T2 hyperintense lesions at Weeks 24 (by 61% and 51%, respectively) and 48 (secondary endpoint; by 67% and 54%, respectively); all p < 0.0001. Every 2 week dosing also provided significant reductions versus placebo and every 4 week dosing in the number of new T1 hypointense, gadolinium-enhancing, and new active (gadolinium-enhancing plus non-enhancing new T2) lesions (all p < 0.0001), as well as the volume of T2 and T1 lesions (p < 0.05) at Weeks 24 and 48. Significantly more patients dosed every 2 weeks had NEDA versus placebo and every 4 weeks (all p < 0.01) from baseline to Week 48 (33.9% versus 15.1% and 21.5%, respectively [odds ratios, ORs: 2.89 and 1.87]), from baseline to Week 24 (41.0% versus 21.9% and 30.7%, [ORs: 2.47 and 1.57]) and from Week 24 to Week 48 (60.2% versus 28.9% and 36.6%, [ORs: 3.71 and 2.62]). Consistent results were seen when allowing for minimal MRI activity.

Conclusion

During Year 1 of ADVANCE, significantly more RRMS patients receiving peginterferon beta-1a every 2 weeks had NEDA, and early and sustained improvements in all MRI endpoints, versus placebo and every 4 week dosing. NEDA sensitivity analyses align with switch strategies in clinical practice settings and provide insight into future responders/non-responders.

Trial registration

ClinicalTrials.gov: NCT00906399

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-014-0240-x) contains supplementary material, which is available to authorized users.

Quantitative Measurement of tissue damage and recovery within new T2w lesions in pediatric- and adult-onset multiple sclerosis

Background:

Children and adolescents with relapsing–remitting multiple sclerosis (RRMS) have a similar T2 lesion burden as adults matched for disease duration. However, it is unknown whether the degree of tissue destruction within lesions is also similar. Persistent reduced T1-weighted signal intensity within lesions indicates loss of tissue integrity.

Objective:

We aimed to compare change over a 2-year period in T1 intensity within new T2 lesions, from pre-lesion levels to chronic post-lesion levels, between pediatric and adult-onset MS.

Methods:

A two-point intensity-normalization method was used to generate normalized T1-weighted (NT1) images from T1-weighted data in 29 pediatric MS patients (age(mean±SD, years), disease duration (years)=15.7±2.4, 3.9±2.6) and 24 adult MS patients (36.7±8.9, 6.9±4.8). Subjects were imaged at three consecutive timepoints, 1 year apart. For each subject, a ‘new-T2’ lesion mask was created and the NT1 intensities ‘pre-lesion’, ‘peri-lesion’ and ‘post-lesion’ were determined. A longitudinal model was used to capture NT1 changes.

Results:

The NT1 in both groups failed to recover to pre-lesion values by 1 year post-lesion ( p=0.0002), with children showing significantly better recovery than adults ( p=0.0089).

Conclusions:

Both groups showed a significant chronic reduction of T1 intensity within new T2 lesions. However, children showed a significantly greater recovery of T1 intensity, suggesting that MS lesions in the pediatric MS population are less destructive, or that pediatric patients have greater reparative capacity.

Efficacy of delayed-release dimethyl fumarate in relapsing-remitting multiple sclerosis: integrated analysis of the phase 3 trials

Objective

Obtain a more precise estimate of the efficacy of delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) in relapsing multiple sclerosis (MS) and examine the consistency of DMF's effects across patient subgroups stratified by baseline demographic and disease characteristics.

Methods

A prespecified integrated analysis of the randomized, double-blind, placebo-controlled, Phase 3 DEFINE and CONFIRM trials was conducted.

Results

The intent-to-treat population comprised 2301 patients randomized to receive placebo (n = 771) or DMF 240 mg twice daily (BID; n = 769) or three times daily (TID; n = 761). At 2 years, DMF BID and TID reduced the annualized relapse rate by 49% and 49% (both P < 0.0001), risk of relapse by 43% and 47% (both P < 0.0001), risk of 12-week confirmed disability progression by 32% (P = 0.0034) and 30% (P = 0.0059), and risk of 24-week confirmed disability progression by 29% (P = 0.0278) and 32% (P = 0.0177), respectively, compared with placebo. In a subset of patients (MRI cohort), DMF BID and TID reduced the mean number of new/enlarging T2-hyperintense lesions by 78% and 73%, gadolinium-enhancing lesion activity by 83% and 70%, and mean number of new nonenhancing T1-hypointense lesions by 65% and 64% (all P < 0.0001 vs. placebo). Effects were generally consistent across patient subgroups.

Interpretation

The integrated analysis provides a more precise estimate of DMF's efficacy. DMF demonstrated a robust reduction in disease activity and a consistent therapeutic effect across patient subgroups.

Magnetization transfer ratio in the delayed-release dimethyl fumarate DEFINE study

We measured changes in brain magnetization transfer ratio (MTR) as a potential indicator of myelin density in brain tissue of patients with relapsing-remitting multiple sclerosis (RRMS) treated with delayed-release dimethyl fumarate (DMF) in the Phase 3 DEFINE study. DEFINE was a randomized, double-blind, placebo-controlled study in which patients with RRMS were randomized 1:1:1 to 2 years of treatment with delayed-release DMF 240 mg twice daily (BID) or three times daily (TID) or placebo. MTR was analyzed in whole brain and normal-appearing brain tissue (NABT) at baseline, week 24, 1 year, and 2 years in a subset of patients. MTR data from 392 patients were analyzed. Mean percentage reduction from baseline to 2 years in median whole brain MTR was -0.386% in the placebo group vs increases of 0.129% (p = 0.0027) and 0.096% (p = 0.0051) in the delayed-release DMF BID and TID groups, respectively. Similarly, mean percentage reduction from baseline in median NABT MTR was -0.392% with placebo vs increases of 0.190% (p = 0.0006) and 0.115% (p = 0.0029) with delayed-release DMF BID and TID, respectively. Post hoc analysis of data from patients with no new or enlarging T2 lesions (n = 147), or who experienced no relapses (n = 238), yielded similar results. In this analysis, increases in MTR in brain tissue most likely reflect increases in myelin density in response to delayed-release DMF. These data in patients with RRMS are consistent with preclinical studies that indicate a potential for cytoprotection and remyelination with delayed-release DMF treatment.

Peginterferon beta-1a in multiple sclerosis: 2-year results from ADVANCE

OBJECTIVE

To evaluate the efficacy and safety of subcutaneous peginterferon beta-1a over 2 years in patients with relapsing-remitting multiple sclerosis in the ADVANCE study.

METHODS

Patients were randomized to placebo or 125 µg peginterferon beta-1a every 2 or 4 weeks. For Year 2 (Y2), patients originally randomized to placebo were re-randomized to peginterferon beta-1a every 2 weeks or every 4 weeks. Patients randomized to peginterferon beta-1a in Year 1 (Y1) remained on the same dosing regimen in Y2.

RESULTS

Compared with Y1, annualized relapse rate (ARR) was further reduced in Y2 with every 2 week dosing (Y1: 0.230 [95% CI 0.183-0.291], Y2: 0.178 [0.136-0.233]) and maintained with every 4 week dosing (Y1: 0.286 [0.231-0.355], Y2: 0.291 [0.231-0.368]). Patients starting peginterferon beta-1a from Y1 displayed improved efficacy versus patients initially assigned placebo, with reductions in ARR (every 2 weeks: 37%, p<0.0001; every 4 weeks: 17%, p=0.0906), risk of relapse (every 2 weeks: 39%, p<0.0001; every 4 weeks: 19%, p=0.0465), 12-week disability progression (every 2 weeks: 33%, p=0.0257; every 4 weeks: 25%, p=0.0960), and 24-week disability progression (every 2 weeks: 41%, p=0.0137; every 4 weeks: 9%, p=0.6243). Over 2 years, greater reductions were observed with every 2 week versus every 4 week dosing for all endpoints and peginterferon beta-1a was well tolerated.

CONCLUSIONS

Peginterferon beta-1a efficacy is maintained beyond 1 year, with greater effects observed with every 2 week versus every 4 week dosing, and a similar safety profile to Y1.Clinicaltrials.gov

REGISTRATION NUMBER

NCT00906399.

Epitope spreading as an early pathogenic event in pediatric multiple sclerosis

OBJECTIVES

For most adults with initial clinical presentation of multiple sclerosis (MS), biological disease was likely initiated many years prior. Pediatric-onset MS provides an opportunity to study early disease processes.

METHODS

Using antigen microarrays, including CNS-related proteins, lipids, and other autoantigens, we studied early immunologic events involved in clinical onset of pediatric MS. Serum samples were collected at the time of incident acquired CNS demyelinating syndromes (ADS) in children who, in subsequent prospective follow-up, were ascertained to have either pediatric MS (ADS-MS) or a monophasic illness (ADS-mono). Samples were obtained both at the time of ADS presentation and 3 months into follow-up. We used an initial training set of samples to implicate antibody signatures associated with each group, and then a test set. An additional set of follow-up samples (stability set) was used as a form of internal validation.

RESULTS

Children with ADS-MS tended to have distinguishable serum antibody patterns both at the time of ADS presentation and 3 months into follow-up. At the time of ADS, serum samples from patients with ADS-MS or ADS-mono reacted against similar numbers of CNS antigens, although CNS antigens implicated in adult MS were more often targeted in children with ADS-MS. The follow-up ADS-MS samples reacted against a broader panel of CNS antigens, while corresponding ADS-mono samples exhibited a contraction of the initial antibody response.

CONCLUSIONS

Our findings in this prospective cohort of pediatric-onset CNS demyelinating diseases point to an active process of epitope spreading during early stages of MS, not seen in monophasic CNS inflammatory conditions.

Onset of multiple sclerosis before adulthood leads to failure of age-expected brain growth

OBJECTIVE

To determine the impact of pediatric-onset multiple sclerosis (MS) on age-expected brain growth.

METHODS

Whole brain and regional volumes of 36 patients with relapsing-remitting MS onset prior to 18 years of age were segmented in 185 longitudinal MRI scans (2-11 scans per participant, 3-month to 2-year scan intervals). MRI scans of 25 age- and sex-matched healthy normal controls (NC) were also acquired at baseline and 2 years later on the same scanner as the MS group. A total of 874 scans from 339 participants from the NIH-funded MRI study of normal brain development acquired at 2-year intervals were used as an age-expected healthy growth reference. All data were analyzed with an automatic image processing pipeline to estimate the volume of brain and brain substructures. Mixed-effect models were built using age, sex, and group as fixed effects.

RESULTS

Significant group and age interactions were found with the adjusted models fitting brain volumes and normalized thalamus volumes (p < 10(-4)). These findings indicate a failure of age-normative brain growth for the MS group, and an even greater failure of thalamic growth. In patients with MS, T2 lesion volume correlated with a greater reduction in age-expected thalamic volume. To exclude any scanner-related influence on our data, we confirmed no significant interaction of group in the adjusted models between the NC and NIH MRI Study of Normal Brain Development groups.

CONCLUSIONS

Our results provide evidence that the onset of MS during childhood and adolescence limits age-expected primary brain growth and leads to subsequent brain atrophy, implicating an early onset of the neurodegenerative aspect of MS.

Magnetization transfer ratio recovery in new lesions decreases during adolescence in pediatric-onset multiple sclerosis patients

Children and adolescents diagnosed with multiple sclerosis rarely accrue physical disability early in their disease. This could be explained by greater remyelination in children, a capacity that may be lost in adolescence or early adulthood. Magnetization transfer ratio (MTR) MRI can be used to quantify changes in myelin in MS. We used serial MTR imaging and longitudinal random effects analysis to quantify recovery of MTR in acute lesions and to evaluate MTR changes in normal-appearing tissue in 19 adolescent MS patients. Our objective was to determine whether younger adolescents have a greater capacity for remyelination and whether this decreases as patients approach adulthood. We detected a significant decrease in MTR recovery between ages 16 and 20 years (p = 0.023), with older subjects approaching typical recovery levels for adult-onset MS. MTR recovery in acute MS lesions decreases with age in adolescents, suggesting loss of remyelination capacity. This may be related to the conclusion of primary myelination or other developmental factors.

Effects of delayed-release dimethyl fumarate on MRI measures in the Phase 3 DEFINE study

In the Phase 3 DEFINE study, delayed-release dimethyl fumarate (DMF) 240 mg twice (BID) and three times daily (TID) significantly reduced the mean number of new or enlarging T2-hyperintense lesions and gadolinium-enhancing (Gd+) lesion activity at 2 years in patients (MRI cohort; n = 540) with relapsing-remitting MS. The analyses described here expand on these results by considering additional MRI measures (number of T1-hypointense lesions; volume of T2-hyperintense, Gd+, and T1-hypointense lesions; brain atrophy), delineating the time course of the effects, and examining the generality of the effects across a diverse patient population. Reductions in lesion counts with delayed-release DMF BID and TID, respectively, vs. placebo were apparent by the first MRI assessment at 6 months [T2-hyperintense: 80 and 69 % reduction (both P < 0.0001); Gd+, 94 and 81 % reduction (both P < 0.0001); T1-hypointense: 58 % (P < 0.0001) and 48 % (P = 0.0005) reduction] and maintained at 1 and 2 years. Reductions in lesion volume were statistically significant beginning at 6 months for T2-hyperintense [P = 0.0002 (BID) and P = 0.0035 (TID)] and Gd+ lesions [P = 0.0059 (BID) and P = 0.0176 (TID)] and beginning at 1 year [P = 0.0126 (BID)] to 2 years [P = 0.0063 (TID)] for T1-hypointense lesions. Relative reductions in brain atrophy from baseline to 2 years (21 % reduction; P = 0.0449) and 6 months to 2 years (30 % reduction; P = 0.0214) were statistically significant for delayed-release DMF BID. The effect of delayed-release DMF on mean number of new or enlarging T2-hyperintense lesions and Gd+ lesion activity was consistent across pre-specified patient subpopulations. Collectively, these results suggest that delayed-release DMF favorably affects multiple aspects of MS pathophysiology.

Correlation between brain volume change and T2 relaxation time induced by dehydration and rehydration: implications for monitoring atrophy in clinical studies

Brain volume change measured from magnetic resonance imaging (MRI) provides a widely used and useful in vivo measure of irreversible tissue loss. These measurements, however, can be influenced by reversible factors such as shifts in brain water content. Given the strong effect of water on T2 relaxation, we investigated whether an estimate of T2 relaxation time would correlate with brain volume changes induced by physiologically manipulating hydration status. We used a clinically feasible estimate of T2 ("pseudo-T2") computed from a dual turbo spin-echo MRI sequence and correlated pseudo-T2 changes to percent brain volume changes in 12 healthy subjects after dehydration overnight (16-hour thirsting) and rehydration (drinking 1.5 L of water). We found that the brain volume significantly increased between the dehydrated and rehydrated states (mean brain volume change = 0.36%, p = 0.0001) but did not change significantly during the dehydration interval (mean brain volume change = 0.04%, p = 0.57). The changes in brain volume and pseudo-T2 significantly correlated with each other, with marginal and conditional correlations (R (2)) of 0.44 and 0.65, respectively. Our results show that pseudo-T2 may be used in conjunction with the measures of brain volume to distinguish reversible water fluctuations and irreversible brain tissue loss (atrophy) and to investigate disease mechanisms related to neuro-inflammation, e.g., in multiple sclerosis, where edema-related water fluctuations may occur with disease activity and anti-inflammatory treatment.

Imaging of repeated episodes of demyelination and remyelination in multiple sclerosis

Multiple sclerosis (MS) is characterized by the formation of demyelinating lesions in the white matter (WM). However, the timecourse of the evolution of healthy white matter into fully demyelinated lesions in MS is not well understood. We use a recently proposed technique to examine magnetization transfer ratio (MTR) timecourses in lesions segmented from MTR images in patients with relapsing–remitting MS (RRMS) and secondary progressive MS (SPMS). In both groups we found MTR lesions forming both in previously normal appearing WM (de novo lesions) as well as in previously lesional tissue that appears to be experiencing a second round of inflammatory demyelination (repeat lesions). Both de novo and repeat lesions exhibited significant, but incomplete MTR recovery, suggesting partial remyelination; post-lesion MTR values in de novo lesions were similar to pre-lesion values in repeat lesions. Both de novo and repeat lesions were found in subjects in relapsing–remitting and secondary progressive stages of MS, and repeat lesions appeared relatively more common in the secondary progressive phase. These observations support the hypothesis that entirely demyelinated lesions found on histopathology are the result of multiple episodes of demyelination and incomplete remyelination, and may have implications for MS treatment development efforts aimed at neuroprotection and enhancing remyelination.

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We imaged multiple sclerosis lesions with magnetization transfer ratio (MTR) MRI.

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MTR is sensitive and reasonably specific to changes in myelin in MS.

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MTR decrease and recovery (de- and re-myelination) occurred in new and old lesions.

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Fully demyelinated lesions may not be the result of complete failure to remyelinate.

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MS lesions may undergo multiple episodes of demyelination and partial remyelination.

Surface-based analysis reveals regions of reduced cortical magnetization transfer ratio in patients with multiple sclerosis: a proposed method for imaging subpial demyelination

The in vivo detection of subpial cortical gray matter lesions in multiple sclerosis is challenging. We quantified the spatial extent of subpial decreases in the magnetization transfer ratio (MTR) of cortical gray matter in subjects with multiple sclerosis, as such reductions may indicate regions of cortical demyelination. We exploited the unique geometry of cortical lesions by using two-dimensional parametric surface models of the cortex instead of traditional three-dimensional voxel-wise analyses. MTR images were mapped onto intermediate surfaces between the pial and white matter surfaces and were used to compute differences between secondary-progressive MS (n = 12), relapsing-remitting MS (n = 12), and normal control (n = 12) groups as well as between each individual patient and the normal controls. We identified large regions of significantly reduced cortical MTR in secondary-progressive patients when compared with normal controls. We also identified large regions of reduced cortical MTR in 11 individual patients (8 secondary-progressive, 3 relapsing-remitting). The secondary-progressive patients showed larger areas of abnormally low MTR compared with relapsing-remitting patients both at the group level and on an individual basis. The spatial distributions of abnormal MTR preferentially involved cingulate cortex, insula, and the depths of sulci, in agreement with pathological descriptions of subpial gray matter lesion distribution. These findings suggest that our method is a plausible in vivo imaging technique for quantifying subpial cortical demyelinating lesions in patients with multiple sclerosis and, furthermore, can be applied at the typical clinical field strength of 1.5 T.

Clinical efficacy of BG-12 (dimethyl fumarate) in patients with relapsing-remitting multiple sclerosis: subgroup analyses of the DEFINE study

In the double-blind, placebo-controlled, Phase 3 DEFINE study in patients with relapsing–remitting multiple sclerosis, oral BG-12 (dimethyl fumarate) significantly reduced the proportion of patients relapsed (primary endpoint), the annualized relapse rate (ARR), and confirmed disability progression (secondary endpoints) at two years compared with placebo. We investigated the efficacy of BG-12 240 mg twice daily (BID) and three times daily (TID) in patient subgroups stratified according to baseline demographic and disease characteristics including gender, age, relapse history, McDonald criteria, treatment history, expanded disability status scale score, T2 lesion volume, and gadolinium-enhancing lesions. The clinical efficacy of BG-12 was generally consistent across patient subgroups and reflected positive findings in the overall DEFINE study population. Treatment with BG-12 BID and TID reduced the proportion of patients relapsed and the ARR at two years compared with placebo in all patient subgroups. Reductions in the risk of relapse with BG-12 BID vs. placebo ranged from 68% [hazard ratio 0.32 (95% confidence interval (CI) 0.16-0.62)] to 26% [0.74 (0.51-1.09)] and from 66% [0.34 (0.23-0.50)] to 25% [0.75 (0.42-1.36)] with BG-12 TID vs. placebo. BG-12 also reduced the risk of disability progression at two years compared with placebo in most subgroups of patients treated with the BID dosing regimen and in all subgroups treated with the TID regimen. These analyses indicate that treatment with BG-12 is consistently effective across a wide spectrum of patients with relapsing–remitting multiple sclerosis with varied demographic and disease characteristics.

Quantitative determination of regional lesion volume and distribution in children and adults with relapsing-remitting multiple sclerosis

Introduction

Onset of MS occurs during childhood in about 5% of cases. It is unclear whether very young age at MS onset, when the nervous system is still myelinating, affects MS lesion accrual or regional distribution.

Objective

To compare the frequency, volume and distribution of T2 and T1 lesions in children and adults with relapsing-remitting multiple sclerosis (RRMS).

Methods

Lesions were segmented on T2- and T1-weighted MRI images from 29 children and 29 adults with RRMS, matched for disease duration.

Results

All subjects exhibited T2-weighted brain lesions. Children had higher whole-brain T2-weighted-lesion-volume (T2LV) compared to adults (mean (SD) in cm³: 12.76(2.7) vs. 10.03(3.4), p<0.0013). The supratentorial-T2LV was similar in children and adults (8.45(1.7) vs. 7.94(1.7), mean (SD), p = 0.2582), but adults were more likely to have supratentorial lesions (96.5% vs. 68.9%, p<0.012). Children were more likely to have infratentorial-T2-weighted lesions (75.9% vs. 43.4%, p<0.03), specifically in the brainstem (62.1% vs. 26.7%, p<0.019) and the pons (48.3% vs. 17.24%, p<0.024), had higher infratentorial-T2-weighted-lesion counts (4.1(5.6) vs. 1.45(2.3), p<0.021), a greater infratentorial-T2LV (4.31(2.7) vs. 2.08(2.4), p<0.0013), and a greater infratentorial-T1-weighted-lesion-volume (T1LV) (3.7(2.5) vs. 1.08(1.9), p<0.0007). Whole-brain-T1LV was higher in children (9.3(2.5) vs. 6.43(2.1), p>0.001). Adult MS patients had higher supratentorial-T1LV (5.5(0.92) vs. 6.41(2.1), mean (SD), p<0.034), whereas children were more likely to have infratentorial-T1-weighted lesions (58.6% vs. 23.3%, p<0.015).

Discussion

Onset of MS during childhood is associated with a higher volume of brain lesions in the first few years of disease relative to adults. Children with MS are more likely than adults to have T2 and T1 lesions in the infratentorial white matter, raising the possibility of preferential immune targeting of more mature myelin. Children with MS have a lower supratentorial T1 lesion burden, possibly reflecting more effective remyelination and repair in brain regions that are still engaged in active primary myelination.

A randomized placebo-controlled phase III trial of oral laquinimod for multiple sclerosis

The phase III placebo-controlled BRAVO study assessed laquinimod effects in patients with relapsing-remitting MS (RRMS), and descriptively compared laquinimod with interferon beta (IFNβ)-1a (Avonex(®) reference arm). RRMS patients age 18-55 years with Expanded Disability Status Scale (EDSS) scores of 0-5.5 and documented pre-study relapse (≥ 1 in previous year, 2 in previous 2 years, or 1 in previous 1-2 years and ≥ 1 GdE lesion in the previous year) were randomized (1:1:1) to laquinimod 0.6 mg once-daily, matching oral placebo, or IFNβ-1a IM 30 μg once-weekly (rater-blinded design), for 24 months. The primary endpoint was annualized relapse rate (ARR); secondary endpoints included percent brain volume change (PBVC) and 3-month confirmed disability worsening. In all, 1,331 patients were randomized: laquinimod (n = 434), placebo (n = 450), and IFNβ-1a (n = 447). ARR was not significantly reduced with laquinimod [-18 %, risk ratio (RR) = 0.82, 95 % CI 0.66-1.02; p = 0.075] vs. placebo. Laquinimod significantly reduced PBVC (28 %, p < 0.001). Confirmed disability worsening was infrequent (10 % laquinimod, 13 % placebo). The change in confirmed disability worsening with laquinimod measured using EDSS was -31 % [hazard ratio (HR) 0.69, p = 0.063], and using Multiple Sclerosis Functional Composite (MSFC) z-score was -77 % (p = 0.150), vs. placebo. IFNβ-1a reduced ARR 26 % (RR = 0.74, 95 % CI 0.60-0.92, p = 0.007), showed no effect on PBVC loss (+11 %, p = 0.14), and changes in disability worsening were -26 and -66 % as measured using the EDSS (HR 0.742, p = 0.13) and MSFC (p = 0.208), respectively. Adverse events occurred in 75, 82, and 70 % of laquinimod, IFNβ-1a, and placebo patients, respectively. Once-daily oral laquinimod 0.6 mg resulted in statistically nonsignificant reductions in ARR and disability progression, but significant reductions in brain atrophy vs. placebo. Laquinimod was well-tolerated.

Treatment effect on brain atrophy correlates with treatment effect on disability in multiple sclerosis

OBJECTIVE

To evaluate the extent to which treatment effect on brain atrophy is able to mediate, at the trial level, the treatment effect on disability progression in relapsing-remitting multiple sclerosis (RRMS).

METHODS

We collected all published randomized clinical trials in RRMS lasting at least 2 years and including as endpoints disability progression (defined as 6 or 3 months confirmed 1-point increase on the Expanded Disability Status Scale), active magnetic resonance imaging (MRI) lesions (defined as new/enlarging T2 lesions), and brain atrophy (defined as change in brain volume between month 24 and month 6-12). Treatment effects were expressed as relative reductions. A linear regression, weighted for trial size and duration, was used to assess the relationship between the treatment effects on MRI markers and on disability progression.

RESULTS

Thirteen trials including >13,500 RRMS patients were included in the meta-analysis. Treatment effects on disability progression were correlated with treatment effects both on brain atrophy (R(2)  = 0.48, p = 0.001) and on active MRI lesions (R(2)  = 0.61, p < 0.001). When the effects on both MRI endpoints were included in a multivariate model, the correlation was higher (R(2)  = 0.75, p < 0.001), and both variables were retained as independently related to the treatment effect on disability progression.

INTERPRETATION

In RRMS, the treatment effect on brain atrophy is correlated with the effect on disability progression over 2 years. This effect is independent of the effect of active MRI lesions on disability; the 2 MRI measures predict the treatment effect on disability more closely when used in combination.

No evidence for impairment of venous hemodynamics in children or young adults with pediatric-onset multiple sclerosis

BACKGROUND AND PURPOSE

Chronic cerebrospinal venous insufficiency is a postulated etiologic factor for multiple sclerosis, but the higher frequency with longer disease duration and progressive disability suggests that chronic cerebrospinal venous insufficiency is secondary to chronic disease. We evaluated the presence of chronic cerebrospinal venous insufficiency in pediatric-onset MS.

MATERIALS AND METHODS

Twenty-six pediatric patients with MS (18 years of age or younger), 26 age-matched healthy controls, and 13 young adults with pediatric-onset MS underwent sonography of the internal jugular, vertebral, and deep cerebral veins. Five venous hemodynamic criteria were assessed, with 2 criteria required for chronic cerebrospinal venous insufficiency. MR imaging studies, performed in the pediatric patients with MS and healthy control groups, included intracranial 2D time-of-flight MR venography and velocity-sensitive phase-contrast sequences. Contrast-enhanced brain MR images were obtained in pediatric patients with MS to further evaluate venous patency. We used paired t tests, Wilcoxon matched pairs, McNemar tests, and exact conditional logistic regression to estimate the association of chronic cerebrospinal venous insufficiency with MS.

RESULTS

Fifty participants (73.5%) had normal ultrasound findings, 15 (23.1%) met 1 venous hemodynamic criterion, and 2 pediatric patients with MS and 1 young adult with pediatric-onset MS met chronic cerebrospinal venous insufficiency criteria. Chronic cerebrospinal venous insufficiency was not associated with MS (odds ratio, 2.41; 95% CI, 0.19-infinity). Demographic and disease characteristics did not differ between the patients with MS meeting chronic cerebrospinal venous insufficiency criteria (n = 3) and those who did not (n = 36; all, P > .05). The mean (SD) MR imaging measures of intracerebral flow did not differ between the 2 pediatric patients with MS meeting chronic cerebrospinal venous insufficiency criteria (0.85 ± 0.11) and healthy controls (0.87 ± 0.16, P = .50); no child demonstrated venous obstruction.

CONCLUSIONS

Chronic cerebrospinal venous insufficiency is rarely observed in children or young adults with pediatric-onset MS. Venous anatomy and flow rates indicate that venous outflow is intact in pediatric patients with MS. Our findings argue against chronic cerebrospinal venous insufficiency as a component of MS etiology.

Jacobian integration method increases the statistical power to measure gray matter atrophy in multiple sclerosis

Gray matter atrophy provides important insights into neurodegeneration in multiple sclerosis (MS) and can be used as a marker of neuroprotection in clinical trials. Jacobian integration is a method for measuring volume change that uses integration of the local Jacobian determinants of the nonlinear deformation field registering two images, and is a promising tool for measuring gray matter atrophy. Our main objective was to compare the statistical power of the Jacobian integration method to commonly used methods in terms of the sample size required to detect a treatment effect on gray matter atrophy. We used multi-center longitudinal data from relapsing-remitting MS patients and evaluated combinations of cross-sectional and longitudinal pre-processing with SIENAX/FSL, SPM, and FreeSurfer, as well as the Jacobian integration method. The Jacobian integration method outperformed these other commonly used methods, reducing the required sample size by a factor of 4-5. The results demonstrate the advantage of using the Jacobian integration method to assess neuroprotection in MS clinical trials.