Mariko Kita

In Active Relapsing-Remitting Multiple Sclerosis, Effector T Cell Resistance to Adaptive Tregs Involves IL-6–Mediated Signaling

Effector T cells in patients with active RRMS can be resistant to immune tolerance through a mechanism involving IL-6R signaling. A Pocket of Resistance The human immune system is a well-oiled machine, primed to quickly and ruthlessly destroy unwanted invaders. However, the wrong stimulus could set immune cells down another path—attacking the very host they’re there to protect. Fortunately, built-in regulatory mechanisms, such as regulatory T cells (Tregs), prevent just such an attack. These cells can suppress the function of effector T cells (Teffs), but what happens when Teffs are resistant to Treg-mediated suppression? Schneider et al. now report that some Teffs are resistant to Tregs in patients with active relapsing-remitting multiple sclerosis (RRMS) and that this resistance is dependent on interleukin-6 (IL-6) signaling. Although Treg resistance has been reported in other autoimmune diseases, little has been known about whether and how it contributes to RRMS pathogenesis. The authors first demonstrated that Teffs from RRMS patients, but not healthy controls, were resistant to the suppressive effects of Tregs. Moreover, they noticed increased expression of IL-6 signaling molecules in active RRMS subjects. If they blocked the IL-6 pathway ex vivo (by blocking STAT3 phosphorylation), Teffs from RRMS patients were no longer resistant to Tregs. Therefore, the IL-6 signaling pathway may serve as a target for reversing pathogenesis in RRMS patients. Patients with multiple sclerosis (MS) manifest demyelination and neurodegeneration mediated in part by CD4+ T cells that have escaped regulation. Resistance of pathogenic effector T cells (Teffs) to suppression by regulatory T cells (Tregs) has been demonstrated in several autoimmune diseases. Although impairment in Treg number and function has been observed in relapsing-remitting MS (RRMS), Teff resistance has not been well studied in this disease. To determine whether Teff resistance contributes to failed tolerance in RRMS, we performed Treg suppression assays with Teffs from either RRMS patients not on immunomodulatory therapy or healthy individuals. Teff resistance was present in the Teffs of RRMS patients with active disease but not from patients with inactive disease. Interleukin-6 (IL-6) and phosphorylation of signal transducer and activator of transcription 3 (pSTAT3) promote Teff resistance to Tregs, and we found an increase in IL-6 receptor α (IL-6Rα) expression and elevated IL-6 signaling as measured by pSTAT3 in our RRMS subjects. Further, the impaired suppression in RRMS subjects correlated with an increase in IL-6Rα surface expression on CD4+ T cells and an increase in pSTAT3 in response to IL-6. To address whether the enhanced pSTAT3 contributed to Teff resistance in active RRMS patients, we blocked STAT3 phosphorylation and found that impaired suppression was reversed. Therefore, enhanced IL-6R signaling through pSTAT3, in some cases through increased IL-6Rα expression, contributed to Teff resistance in active RRMS. These markers may aid in determining disease activity and responsiveness to immunomodulatory therapies in RRMS.

BG-12 (dimethyl fumarate): a review of mechanism of action, efficacy, and safety

Abstract Background: Multiple sclerosis (MS) is a chronic inflammatory disease, affecting more than 2.5 million people worldwide with more 400,000 cases in the United States alone. There has been considerable improvement in the treatment of MS, with the introduction of disease-modifying drugs; however, new oral therapies may provide additional benefit by providing an alternative treatment modality and the potential for improved adherence by avoiding the injection-associated side effects and anxiety encountered with some first-line agents. BG-12 (dimethyl fumarate) is an oral agent approved in the United States for the treatment of relapsing forms of MS. Scope: We review published literature about what is known about the mechanism of action of BG-12, and key efficacy and safety findings from three clinical studies in patients with relapsing-remitting MS (RRMS). Findings: Data from preclinical studies have demonstrated that BG-12 may promote anti-inflammatory and cytoprotective activities that are mediated, at least in part, by the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) antioxidant response pathway. Studies in animals have shown a protective effect of BG-12 on neuronal, axonal and myelin integrity. Results from a phase 2 study and two randomized double-blind placebo-controlled phase 3 studies, CONFIRM and DEFINE, have shown that BG-12 provides clinical and radiologic efficacy in patients with RRMS. At 2 years, BG-12 240 mg twice and three times daily reduced annualized relapse rate (CONFIRM primary endpoint) by 44% and 51% and the risk of relapse (DEFINE primary endpoint) by 49% and 50%, respectively, compared with placebo (all p < 0.001). BG-12 was generally well tolerated and had an acceptable safety profile, with a similar incidence of adverse events across treatment groups. Conclusions: BG-12 may have cytoprotective and anti-inflammatory properties that contribute to its efficacy among patients with RRMS. Findings from phase 2 and 3 studies further support BG-12 as an effective initial therapy. ClinicalTrials.gov ID: NCT00168701; NCT00420212: NCT00451451.

MRI lesion volume heterogeneity in primary progressive MS in relation with axonal damage and brain atrophy

Objectives: To investigate whether axonal damage in primary progressive (PP) multiple sclerosis (MS), as measured by proton magnetic resonance spectroscopy (HMRS) imaging and brain atrophy, is a function of T2 weighted brain lesion volume. Methods: 34 PP MS patients were divided into two categories: low (<3 cm3, n = 18) or high (≥3 cm3, n = 16) T2 lesion load (LL). An Index of Brain Atrophy (IBA) was calculated and HMRS metabolite ratios were derived from a central brain area centred at the corpus callosum. Results: Patient groups did not differ with regard to clinical characteristics and showed lower mean IBA and mean N-acetylaspartate:creatinine (NAA:Cr) ratios compared to healthy controls. Conclusion: PP patients with low and high brain T2LL have detectable brain atrophy and NAA:Cr reduction compared to healthy controls. In PP MS, T2 lesions alone are insufficient to explain the presence of brain atrophy and decrease in NAA:Cr.

Magnetization transfer ratio in new MS lesions before and during therapy with IFNβ-1a

Objective: The authors examined the effect of 6.0 MIU interferon beta-1a (IFNβ-1a) administered IM each week on the evolution of monthly magnetization transfer ratio (MTR) within new gadolinium-enhancing (Gd+) lesions in patients with very early relapsing-remitting (RR) MS. Background: IFNβ is an effective disease-modifying treatment for patients with RRMS. Among other effects, it has been shown to decrease the number of new Gd+ and T2-weighted lesions. MTR is a putative marker for irreversible tissue damage and evolution of MTR within a lesion may reflect recovery of tissue damage. It is not known whether IFNβ-1a affects the recovery phase of lesions. Methods: Eight untreated patients with RRMS who completed up to 14 monthly brain MRI sessions elected to initiate treatment with IFNβ-1a. Four out of eight patients developed new Gd+ lesions during treatment. MTR of lesions at the time of appearance and subsequent rate of change of monthly MTR were compared before and after treatment (stratified Mann-Whitney test). Results: The difference between MTR at appearance of 47 new Gd+ lesions before treatment versus 23 new Gd+ lesions during treatment was not significant. Twenty-two of 47 new Gd+ lesions before treatment and 11 of 23 new Gd+ lesions after treatment were monitored for up to 6 months. After appearance of new Gd+ lesions, the rate of increase in MTR was faster during therapy (p = 0.037). Conclusion: MTR abnormalities within new Gd+ lesions evolve at a faster rate during treatment with IFNβ-1a than before initiating therapy. This is consistent with the hypothesis that IFNβ-1a promotes resolution of new Gd+ lesions.

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

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 DMFs effects across patient subgroups stratified by baseline demographic and disease characteristics.

Effects of BG-12 (dimethyl fumarate) on health-related quality of life in patients with relapsing–remitting multiple sclerosis: findings from the CONFIRM study

Multiple sclerosis (MS) has a significant impact on health-related quality of life (HRQoL) with symptoms adversely affecting many aspects of everyday living. BG-12 (dimethyl fumarate) demonstrated significant efficacy in the phase III studies DEFINE and CONFIRM in patients with relapsing–remitting MS. In CONFIRM, HRQoL was worse in patients with greater disability at baseline, and who relapsed during the study, and improved with BG-12 treatment. Mean Short Form-36 Physical Component Summary scores for BG-12 increased over 2 years and scores for placebo decreased. Coupled with clinical and neuroradiological benefits, these HRQoL results further support BG-12 as an effective oral treatment for relapsing MS.

Randomized controlled trial of atorvastatin in clinically isolated syndrome: The STAyCIS study

Objective: To test efficacy and safety of atorvastatin in subjects with clinically isolated syndrome (CIS). Methods: Subjects with CIS were enrolled in a phase II, double-blind, placebo-controlled, 14-center randomized trial testing 80 mg atorvastatin on clinical and brain MRI activity. Brain MRIs were performed quarterly. The primary endpoint (PEP) was development of ≥3 new T2 lesions, or one clinical relapse within 12 months. Subjects meeting the PEP were offered additional weekly interferon β-1a (IFNβ-1a). Results: Due to slow recruitment, enrollment was discontinued after 81 of 152 planned subjects with CIS were randomized and initiated study drug. Median (interquartile range) numbers of T2 and gadolinium-enhancing (Gd) lesions were 15.0 (22.0) and 0.0 (0.0) at baseline. A total of 53.1% of atorvastatin recipients (n = 26/49) met PEP compared to 56.3% of placebo recipients (n = 18/32) (p = 0.82). Eleven atorvastatin subjects (22.4%) and 7 placebo subjects (21.9%) met the PEP by clinical criteria. Proportion of subjects who did not develop new T2 lesions up to month 12 or to starting IFNβ-1a was 55.3% in the atorvastatin and 27.6% in the placebo group (p = 0.03). Likelihood of remaining free of new T2 lesions was significantly greater in the atorvastatin group compared with placebo (odds ratio [OR] = 4.34, p = 0.01). Likelihood of remaining free of Gd lesions tended to be higher in the atorvastatin group (OR = 2.72, p = 0.11). Overall, atorvastatin was well tolerated. No clear antagonistic effect of atorvastatin plus IFNβ-1a was observed on MRI measures. Conclusion: Atorvastatin treatment significantly decreased development of new brain MRI T2 lesion activity, although it did not achieve the composite clinical and imaging PEP. Classification of Evidence: This study provided Class II evidence that atorvastatin did not reduce the proportion of patients with CIS meeting imaging and clinical criteria for starting immunomodulating therapy after 12 months, compared to placebo. In an analysis of a secondary endpoint (Class III), atorvastatin was associated with a reduced risk for developing new T2 lesions.

Effects of delayed-release dimethyl fumarate on MRI measures in the phase 3 CONFIRM study

Objective: To evaluate the effects of oral delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) on MRI lesion activity and load, atrophy, and magnetization transfer ratio (MTR) measures from the Comparator and an Oral Fumarate in Relapsing-Remitting Multiple Sclerosis (CONFIRM) study. Methods: CONFIRM was a 2-year, placebo-controlled study of the efficacy and safety of DMF 240 mg twice (BID) or 3 times daily (TID) in 1,417 patients with relapsing-remitting multiple sclerosis (RRMS); subcutaneous glatiramer acetate 20 mg once daily was included as an active reference comparator. The number and volume of T2-hyperintense, T1-hypointense, and gadolinium-enhancing (Gd+) lesions, as well as whole brain volume and MTR, were assessed in 681 patients (MRI cohort). Results: DMF BID and TID produced significant and consistent reductions vs placebo in the number of new or enlarging T2-hyperintense lesions and new nonenhancing T1-hypointense lesions after 1 and 2 years of treatment and in the number of Gd+ lesions at week 24, year 1, and year 2. Lesion volumes were also significantly reduced. Reductions in brain atrophy and MTR changes with DMF relative to placebo did not reach statistical significance. Conclusions: The robust effects on MRI active lesion counts and total lesion volume in patients with RRMS demonstrate the ability of DMF to exert beneficial effects on inflammatory lesion activity in multiple sclerosis, and support DMF therapy as a valuable new treatment option in RRMS. Classification of evidence: This study provides Class I evidence of reduction in brain lesion number and volume, as assessed by MRI, over 2 years of delayed-release DMF treatment.

Effects of Delayed-Release Dimethyl Fumarate (DMF) on Health-Related Quality of Life in Patients With Relapsing-Remitting Multiple Sclerosis: An Integrated Analysis of the Phase 3 DEFINE and CONFIRM Studies

PURPOSE Delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) has been reported to have clinical and neuroradiologic efficacy in people with relapsing-remitting multiple sclerosis (RRMS) in the Phase 3 DEFINE and CONFIRM studies. An integrated analysis of data from DEFINE and CONFIRM was conducted to estimate more precisely the therapeutic effects of delayed-release DMF. Here we describe the impact of RRMS on health-related quality of life (HRQoL) at baseline and assess the effects of delayed-release DMF on prespecified HRQoL end points over 2 years. METHODS Patients with RRMS were randomly assigned to receive delayed-release DMF 240 mg PO BID or TID or matching placebo for up to 2 years (96 weeks). As a tertiary end point in both studies, patient-reported HRQoL was assessed using the Physical and Mental Component Summaries (PCS and MCS, respectively) of the 36-item Short Form Health Survey (SF-36); global assessment of well-being, as measured on a visual analog scale (VAS); and the EuroQoL-5D (EQ-5D) VAS, administered at baseline and at weeks 24, 48, and 96. Higher scores suggested better HRQoL. FINDINGS The integrated analysis included 2301 patients treated with delayed-release DMF BID (n = 769) or TID (n = 761) or placebo (n = 771). The mean PCS and MCS scores at baseline were lower overall compared with those reported in the general US population and were ≥5 points lower (a clinically meaningful difference) in patients with a baseline Expanded Disability Status Scale (EDSS) score of ≥2.5 compared with those in patients with a baseline EDSS score of 0. At 2 years, mean PCS and MCS scores were increased from baseline in the patients treated with delayed-release DMF, whereas the mean PCS and MCS scores were decreased from baseline in the placebo group; the difference in PCS and MCS scores was significant for the delayed-release DMF BID and TID groups compared with placebo. SF-36 subscale scores generally remained stable or were improved relative to baseline in patients treated with delayed-release DMF and decreased in patients receiving placebo; improvements were significant for delayed-release DMF BID and TID versus placebo on most subscales. Compared with that in the placebo group, the proportions of patients in the delayed-release DMF groups exhibiting a ≥5-point improvement in SF-36 score were significantly higher. The following factors were found to be predictive of improved PCS and MCS scores at 2 years: delayed-release DMF treatment, lower baseline EDSS score, age ≤40 years (PCS only), and corresponding lower baseline PCS or MCS score. Changes from baseline in VAS and EuroQoL-5D scores were generally consistent with changes in SF-36 scores. IMPLICATIONS These HRQoL benefits parallel the improvements in clinical and magnetic resonance imaging end points with delayed-release DMF, suggesting that delayed-release DMF treatment improves patient-perceived health status as well as neurologic and physical functioning. ClinicalTrials.gov identifiers: NCT0042012; NCT00451451.

Mitoxantrone as a potential therapy for primary progressive multiple sclerosis

Mitoxantrone (Novantrone®) was the first drug approved in western Europe and North A merica for treatment of secondary progressive multiple sclerosis (SPMS) and progressive relapsing MS (PRMS). Pharmacological properties of mitoxantrone, its role in SPMS, the study rational and design of an ongoing multi-centre, double blind, randomized, placebo -controlled phase 2 trial will be outlined in this article.