A controlled trial of natalizumab for relapsing multiple sclerosis

Extended interval dosing of natalizumab in multiple sclerosis

BACKGROUND

Natalizumab (NTZ), a monoclonal antibody to human α4β1/β7 integrin, is an effective therapy for multiple sclerosis (MS), albeit associated with progressive multifocal leukoencephalopathy (PML). Clinicians have been extending the dose of infusions with a hypothesis of reducing PML risk. The aim of the study is to evaluate the clinical consequences of reducing NTZ frequency of infusion up to 8 weeks 5 days.

METHODS

A retrospective chart review in 9 MS centres was performed in order to identify patients treated with extended interval dosing (EID) regimens of NTZ. Patients were stratified into 3 groups based on EID NTZ treatment schedule in individual centres: early extended dosing (EED; n=249) every 4 weeks 3 days to 6 weeks 6 days; late extended dosing (LED; n=274) every 7 weeks to 8 weeks 5 days; variable extended dosing (n=382) alternating between EED and LED. These groups were compared with patients on standard interval dosing (SID; n=1093) every 4 weeks.

RESULTS

17% of patients on SID had new T2 lesions compared with 14% in EID (p=0.02); 7% of patients had enhancing T1 lesions in SID compared with 9% in EID (p=0.08); annualised relapse rate was 0.14 in the SID group, and 0.09 in the EID group. No evidence of clinical or radiographic disease activity was observed in 62% of SID and 61% of EID patients (p=0.83). No cases of PML were observed in EID group compared with 4 cases in SID cohort.

CONCLUSIONS

Dosing intervals up to 8 weeks 5 days did not diminish effectiveness of NTZ therapy. Further monitoring is ongoing to evaluate if the risk of PML is reduced in patients on EID.

Postarrest stalling rather than crawling favors CD8(+) over CD4(+) T-cell migration across the blood-brain barrier under flow in vitro

Although CD8⁺ T cells have been implied in the pathogenesis of multiple sclerosis (MS), the molecular mechanisms mediating CD8⁺ T‐cell migration across the blood–brain barrier (BBB) into the central nervous system (CNS) are ill defined. Using in vitro live cell imaging, we directly compared the multistep extravasation of activated CD4⁺ and CD8⁺ T cells across primary mouse brain microvascular endothelial cells (pMBMECs) as a model for the BBB under physiological flow. Significantly higher numbers of CD8⁺ than CD4⁺ T cells arrested on pMBMECs under noninflammatory and inflammatory conditions. While CD4⁺ T cells polarized and crawled prior to their diapedesis, the majority of CD8⁺ T cells stalled and readily crossed the pMBMEC monolayer preferentially via a transcellular route. T‐cell arrest and crawling were independent of G‐protein‐coupled receptor signaling. Rather, absence of endothelial ICAM‐1 and ICAM‐2 abolished increased arrest of CD8⁺ over CD4⁺ T cells and abrogated T‐cell crawling, leading to the efficient reduction of CD4⁺, but to a lesser degree of CD8⁺, T‐cell diapedesis across ICAM‐1^null/ICAM‐2^−/− pMBMECs. Thus, cellular and molecular mechanisms mediating the multistep extravasation of activated CD8⁺ T cells across the BBB are distinguishable from those involved for CD4⁺ T cells.

Slowly eroding lesions in multiple sclerosis

BACKGROUND

At autopsy, 20%-40% of chronic multiple sclerosis (MS) lesions are labeled "slowly expanding" and feature myelin phagocytosis at the lesion edge. As pathological lesion classification relies on a single, terminal time point, the rate of lesion expansion cannot be directly measured.

OBJECTIVE

To study long-term volume changes in individual MS lesions.

METHODS

Volumes of individual lesions on proton density magnetic resonance imaging (MRI) acquired between 1992 and 2015 were measured in 22 individuals (one lesion per person). After correction for acquisition protocol, a mixed model evaluated lesion volume changes.

RESULTS

The mean (standard deviation) lesion volume at baseline was 142 (82) mL, falling to 74 (51) mL after 16 (3) years. All lesions shrank over time. Change in lesion volume did not correlate with change in supratentorial brain volume ( p = 0.33). In simulations, the results could be explained by a process of slow radial expansion superimposed on substantially more rapid resorption of damaged tissue.

CONCLUSION

We noted sustained radiological contraction of MS lesions, a surprising result given that fresh myelin breakdown products within chronic active lesions are observed relatively frequently at autopsy. Therefore, the primary pathological process in chronic lesions, even those described as "slowly expanding," is likely to be tissue loss.

Relapse rates and enhancing lesions in a phase II trial of natalizumab in multiple sclerosis

Background: Natalizumab, a humanized monoclonal IgG4 antibody, is an a4-integrin antagonist, which inhibits the migration of inflammatory cells into the central nervous system, a key pathogenic mechanism in multiple sclerosis (MS). In a six month, phase II clinical trial of patients with relapsing MS, natalizumab significantly reduced the formation of new gadolinium-enhanced (Gd +) lesions and the number of clinical relapses. Objective: To investigate the relationship of historical relapse rate and new Gd+ lesion number with subsequent MS disease activity and natalizumab treatment in the phase II study. Methods: Patients who participated in the phase II study were stratified into subgroups according to: (i) the number of relapses in the two years prior to entry into the study: 2 relapses (n=108), 3 relapses (n=57), and-3 relapses (n=48); (ii) the number of new Gd+ lesions at baseline (Month 0): 0 (n=129), 1-2(n=50), and >2(n=33). Relapses and new Gd+ lesions during the treatment phase of the trial were determined and compared for each subgroup. Results: Both the prestudy relapse rate and number of new Gd+ lesions at baseline were related to the subsequent risk of a relapse; baseline number of Gd+ lesions was related to the likelihood of subsequent new Gd+ lesion formation. There was a lower proportion of subjects with an on-study relapse and fewer new Gd+ lesions in all natalizumab-treated subgroups when compared with their placebo counterpart; the difference was most apparent in the subgroups of patients with >3 relapses in the two years prior to study entry and >2 new Gd+ lesions at Month 0. Conclusions: There was a lower proportion of subjects with an on-study relapse in natalizumab-treated patients, particularly in those with a more active disease at study entry. Larger ongoing phase III studies will allow more definitive investigation of these preliminary subgroup findings.

A highly immunogenic trivalent T cell receptor peptide vaccine for multiple sclerosis

Background: T cell receptor (TCR) peptide vaccination is a novel approach to treating multiple sclerosis (MS). The low immunogenicity of previous vaccines has hindered the development of TCR peptide vaccination for MS. Objective: To compare the immunogenicity of intramuscular injections of TCR BV5S2, BV6S5 and BV13S1 CDR2 peptides in incomplete Freund’s adjuvant (IFA) with intradermal injections of the same peptides without IFA. Methods: MS subjects were randomized to receive TCR peptides/IFA, TCR peptides/saline or IFA alone. Subjects were on study for 24 weeks. Results: The TCR peptides/IFA vaccine induced vigorous T cell responses in 100% of subjects completing the 24-week study (9/9) compared with only 20% (2/10) of those receiving the TCR peptides/saline vaccine (P =0.001). IFA alone induced a weak response in only one of five subjects. Aside from injection site reactions, there were no significant adverse events attributable to the treatment. Conclusions: The trivalent TCR peptide in IFA vaccine represents a significant improvement in immunogenicity over previous TCR peptide vaccines and warrants investigation of its ability to treat MS.

Suppression of acute experimental allergic encephalomyelitis with a small molecule inhibitor of α4 integrin

Purpose: To determine the efficacy of a small molecule inhibitor of α4 integrin (CT301) at reversing the clinical, pathological and MR- detectable deficits associated with the acute phase of experimental allergic encephalomyelitis (EAE). Materials and methods: EAE was induced in 36 female Hartley guinea pigs, and the treatment period was from day 11 to day 17 post-immunization. Animals received either saline (n=12), anti-α4 integrin antibody (AN100226m; n=12) or CT301 (n=12). T2-weighted fast spin echo and T1-weighted pre- and post-contrast scans were performed at the beginning (day 11) and end (day 18) of the treatment period, and scored for cerebral inflammation and gadolinium enhancement. T1-weighted images were further analyzed to quantify this enhancement as a measure of blood-brain barrier integrity. Dissected CNS was evaluated for inflammation and demyelination. Results: CT301 successfully reversed two clinical indicators of disease over the course of the treatment period. These animals showed decreased T2-weighted abnormalities, as well as a reduction in gadolinium leakage on T1-weighted images. Meningeal and perivascular inflammation was decreased by anti-α4 integrin treatments. Conclusion: CT301 effectively reverses the clinical, pathological and MR-detectable deficits of acute EAE, and may therefore be a promising therapeutic agent in multiple sclerosis (MS).

An Update on Monoclonal Antibody Therapies in Multiple Sclerosis

Multiple sclerosis (MS) is a complex disease that causes a great deal of disability, especially in the young adult population. There have been several immunomodulatory agents that have been approved by the Food and Drug Administration for MS, including glatiramer acetate, interferon-β 1a and -β 1b, mitoxantrone, and corticosteroids. The effectiveness of these therapies has not been optimal, and drugs, such as monoclonal antibodies, that more selectively target the pathogenetic process of MS have been sought. These agents have their own intrinsic limitations such as systemic inflammatory reactions, induction of neutralizing antiantibodies, and even life-threatening infectious processes. The agent that has been in the forefront of the discussion is natalizumab, a monoclonal antibody (mAb) against α 4 integrin, which shows much promise in suppressing MS activity. However, 3 individuals treated with natalizumab developed a life-threatening infection, progressive multifocal leukoencephalopathy. This article reviews the role of mAbs in the treatment of MS, particularly their advantages over other drugs and their limitations, which have to be overcome for these agents to be at the forefront in the treatment of MS.

A longitudinal uncontrolled study of cerebral gray matter volume in patients receiving natalizumab for multiple sclerosis

OBJECTIVE

Brain atrophy in multiple sclerosis (MS) selectively affects gray matter (GM), which is highly relevant to disability and cognitive impairment. We assessed cerebral GM volume (GMV) during one year of natalizumab therapy.

DESIGN/METHODS

Patients with relapsing-remitting (n = 18) or progressive (n = 2) MS had MRI ∼1 year apart during natalizumab treatment. At baseline, patients were on natalizumab for (mean ± SD) 16.6 ± 10.9 months with age 38.5 ± 7.4 and disease duration 9.7 ± 4.3 years.

RESULTS

At baseline, GMV was 664.0 ± 56.4 ml, Expanded Disability Status Scale (EDSS) score was 2.3 ± 2.0, timed 25-foot walk (T25FW) was 6.1±3.4 s; two patients (10%) had gadolinium (Gd)-enhancing lesions. At follow-up, GMV was 663.9 ± 60.2 mL; EDSS was 2.6 ± 2.1 and T25FW was 5.9 ± 2.9 s. One patient had a mild clinical relapse during the observation period (0.052 annualized relapse rate for the entire cohort). No patients had Gd-enhancing lesions at follow-up. Linear mixed-effect models showed no significant change in annualized GMV [estimated mean change per year 0.338 mL, 95% confidence interval -9.66, 10.34, p = 0.94)], GM fraction (p = 0.92), whole brain parenchymal fraction (p = 0.64), T2 lesion load (p = 0.64), EDSS (p = 0.26) or T25FW (p = 0.79).

CONCLUSIONS

This pilot study shows no GM atrophy during one year of natalizumab MS therapy. We also did not detect any loss of whole brain volume or progression of cerebral T2 hyperintense lesion volume during the observation period. These MRI results paralleled the lack of clinical worsening.

Relapse frequency in transitioning from natalizumab to dimethyl fumarate: assessment of risk factors

Risk of relapse after natalizumab (NAT) cessation and switch to dimethyl fumarate (DMF) is unknown. The objective of this paper is to identify the risk and associated risk factors for relapse after switching from NAT to DMF in relapsing-remitting multiple sclerosis. Patients (n = 30) were treated with NAT for ≥12 months and then switched to DMF in a mean of 50 days. Patient age, annualized relapse rates (ARR), Expanded Disability Status Scale scores (EDSS), and lymphocyte counts were assessed. Overall, eight patients (27 %) had relapses after switching to DMF. Five patients (17 %) suffered severe relapses with multifocal clinical and radiological findings. New lesions by MRI (T2 hyperintense or enhancing) were observed in 35 % of patients. Relapses occurred at a mean of 3.5 months after NAT cessation. Patient age and elevated ARR prior to NAT use were significantly associated with risk of relapse after switch to DMF. Once on DMF for 4 months prior to relapse, lymphocyte count decreased more significantly in patients without relapses than those with relapses. Switching from NAT to DMF correlated with increased relapses. Young patient age, high ARR and stability of lymphocyte counts were risk factors for relapse after transition from NAT to DMF.

Adipose extracellular matrix remodelling in obesity and insulin resistance

The extracellular matrix (ECM) of adipose tissues undergoes constant remodelling to allow adipocytes and their precursor cells to change cell shape and function in adaptation to nutritional cues. Abnormal accumulation of ECM components and their modifiers in adipose tissues has been recently demonstrated to cause obesity-associated insulin resistance, a hallmark of type 2 diabetes. Integrins and other ECM receptors (e.g. CD44) that are expressed in adipose tissues have been shown to regulate insulin sensitivity. It is well understood that a hypoxic response is observed in adipose tissue expansion during obesity progression and that hypoxic response accelerates fibrosis and inflammation in white adipose tissues. The expansion of adipose tissues should require angiogenesis; however, the excess deposition of ECM limits the angiogenic response of white adipose tissues in obesity. While recent studies have focused on the metabolic consequences and the mechanisms of adipose tissue expansion and remodelling, little attention has been paid to the role played by the interaction between peri-adipocyte ECM and their cognate cell surface receptors. This review will address what is currently known about the roles played by adipose ECM, their modifiers, and ECM receptors in obesity and insulin resistance. Understanding how excess ECM deposition in the adipose tissue deteriorates insulin sensitivity would provide us hints to develop a new therapeutic strategy for the treatment of insulin resistance and type 2 diabetes.

Artesunate Ameliorates Experimental Autoimmune Encephalomyelitis by Inhibiting Leukocyte Migration to the Central Nervous System

BACKGROUND AND AIMS

Experimental autoimmune encephalomyelitis (EAE) is T-cell-dependent disease of the central nervous system (CNS) of mice. This model resembles multiple sclerosis (MS) in many aspects. Therapies that focus in the modulation of the immune response and cellular infiltration in the CNS present best effects in the clinics. Artesunate (Art) is a semi-synthetic sesquiterpene derivative from artemisinin and has been shown to reduce the clinical signs of autoimmune disease models through mechanisms not yet understood. In this study, we aimed to evaluate whether administration of Art would ameliorate EAE.

METHODS AND RESULTS

C57BL6 mice were immunized with MOG35-55 peptide to induce EAE. At the same time, Art treatment started (3 mg/kg/day via i.p.) for five consecutive days. We found that Art treatment reduced the clinical signs of EAE and that correlated with a reduced infiltration of cells in the CNS. Disease amelioration did not correlate with immunomodulation as recall responses, leukocyte subpopulations, and gene expression analysis were similar among treated and untreated mice. Ultimately, further analysis provided data indicating that a possible mechanism of action for Art is dependent on the cellular migration to the CNS.

CONCLUSIONS

Artesunate reduces the severity of EAE by inhibiting migration of pathogenic T cells to the CNS.

Novel Therapies for Eosinophilic Disorders

Current therapies for eosinophilic disorders are limited. Most treatment approaches remain empirical, are not supported by data from controlled clinical trials, involve the off-label use of agents developed for treatment of other diseases, and tend to rely heavily on the use of glucocorticoids and other agents with significant toxicity. Great progress has been made in the discovery, preclinical development, and clinical testing of a variety of biologics and small molecules that have the potential to directly or indirectly influence eosinophils, eosinophilic inflammation, and the consequences of eosinophil activation.

The common marmoset as an indispensable animal model for immunotherapy development in multiple sclerosis

New drugs often fail in the translation from the rodent experimental autoimmune encephalomyelitis (EAE) model to human multiple sclerosis (MS). Here, we present the marmoset EAE model as an indispensable model for translational research into MS. The genetic heterogeneity of this species and lifelong exposure to chronic latent infections and environmental pathogens create a human-like immune system. Unique to this model is the presence of the pathological hallmark of progressive MS, in particular cortical grey matter lesions. Another great possibility of this model is systemic and longitudinal immune profiling, whereas in humans and mice immune profiling is usually performed in a single compartment (i.e. blood or spleen, respectively). Overall, the marmoset model provides unique opportunities for systemic drug-effect profiling.

A Randomized Trial Evaluating Various Administration Routes of Natalizumab in Multiple Sclerosis

The study's primary objective was to compare the pharmacokinetics (PK) and pharmacodynamics (PD) of single subcutaneous (SC) or intramuscular (IM) 300-mg doses of natalizumab with IV 300-mg doses of natalizumab in patients with multiple sclerosis (MS). Secondary objectives included investigation of the safety, tolerability, and immunogenicity of repeated SC and IM natalizumab doses. DELIVER was a 32-week, open-label, multicenter study of natalizumab-naive patients with relapsing-remitting MS (RRMS) or secondary progressive MS (SPMS) randomized to receive 300 mg natalizumab by SC injection, IM injection, or IV infusion. PK and PD were evaluated over 8 weeks after the first natalizumab treatment (Part 1) and over 24 weeks with repeated dosing every 4 weeks, beginning at week 8 (Part 2). Seventy-six patients (24 with RRMS and 52 with SPMS) were enrolled in DELIVER. Following SC or IM administration of natalizumab, peak serum concentrations were approximately 40% of those observed with IV administration and showed no major differences in elimination characteristics. Mean bioavailability relative to IV administration was 57.1% to 71.3% with SC administration and 48.7% with IM administration; mean trough serum concentrations were similar with SC or IV administration and lower with IM administration. Following single or multiple doses of natalizumab, PD response was comparable across administration routes and disease stages. No meaningful differences were observed across administration groups in the incidence or nature of overall adverse events, serious adverse events, administration site reactions, hypersensitivity reactions, or antinatalizumab antibodies. These findings support the comparability of PD measures of natalizumab administered IV, SC, or IM.

The "inflammatory penumbra" in ischemic stroke: From clinical data to experimental evidence

Purpose

The objective of the present review is to provide an overview of the available clinical and preclinical data supporting the existence of an "inflammatory penumbra" in ischemic stroke.

Findings

Recent data from clinical trials suggest the existence of an inflammatory area at risk, surrounding the initial ischemic lesion and secondarily infiltrated by lymphocytes, that is ultimately recruited by the ischemic core: called the "inflammatory penumbra." Experimental results support this concept. Lymphocytes, especially T-cells, enter the brain in the perilesional area in a vascular-cell adhesion molecule-1 dependent manner and participate in delayed neuronal cell death.

Methods

For writing this review, we used the more recent publications in the field, including the preclinical and clinical studies. We have also used our own experise in the field of in vivo imaging of inflammatory processes.

Discussion

Consequently, the intensity of the inflammatory reaction and the size of the inflammatory penumbra may vary considerably in patients, as it is the case in experimental stroke models in mice. By analogy with the ischemic penumbra of the acute phase of stroke, this secondary inflammatory penumbra represents a therapeutic opportunity during the subacute phase of stroke. Large clinical trials that target lymphocyte trafficking are currently taking place. However, to improve the benefit of such therapeutic strategies, adequate patient selection may be mandatory.

Conclusion

In this context, innovative imaging methods including magnetic resonance imaging of adhesion molecules may contribute to noninvasively detect this inflammatory penumbra and thus to select patients eligible for such therapy.

Safety and efficacy of the selective sphingosine 1-phosphate receptor modulator ozanimod in relapsing multiple sclerosis (RADIANCE): a randomised, placebo-controlled, phase 2 trial

BACKGROUND

Modulation of sphingosine 1-phosphate (S1P) receptors in a non-selective manner decreases disease activity in patients with multiple sclerosis but has potential safety concerns. We assessed the safety and efficacy of the oral selective S1P receptor modulator ozanimod in patients with relapsing multiple sclerosis.

METHODS

RADIANCE is a combined phase 2/3 trial. Patients with relapsing multiple sclerosis were recruited from 55 academic and private multiple sclerosis clinics in 13 countries across Europe and the USA. Eligible participants were aged 18-55 years, had an Expanded Disability Status Scale (EDSS) score of 0-5·0, and had either one or more relapses in the previous 12 months, or one or more relapses in the past 24 months and one or more gadolinium-enhancing lesions on MRI in the previous 12 months before screening. Participants were assigned by a computer-generated randomisation sequence in a 1:1:1 ratio to ozanimod (0·5 mg or 1 mg) or matching placebo once daily for 24 weeks by an independent, unmasked, statistical team. Trial participants, study site personnel, MRI assessors, steering committee members, and the study statistician were masked to treatment assignment. To attenuate first-dose cardiac effects, ozanimod was up-titrated from 0·25 mg to 0·5 mg or 1 mg over 8 days. The primary endpoint was the cumulative number of total gadolinium-enhancing MRI lesions measured by an independent MRI analysis centre at weeks 12-24 after treatment initiation. Analysis was by intention to treat. Here, we report results from the 24-week phase 2 trial. This trial is registered with ClinicalTrials.gov, number NCT01628393. The 2-year phase 3 trial is ongoing.

FINDINGS

The first patient was randomised on Oct 18, 2012, and the final visit of the last randomised patient was on May 11, 2014. The intention-to-treat and safety population consisted of 258 participants, 88 were assigned placebo, 87 ozanimod 0·5 mg, and 83 ozanimod 1 mg; 252 (98%) patients completed the assigned treatment. The mean cumulative number of gadolinium-enhancing lesions at weeks 12-24 was 11·1 (SD 29·9) with placebo compared with 1·5 (3·7) with ozanimod 0·5 mg (odds ratio 0·16, 95% CI 0·08-0·30; p<0·0001) and 1·5 (3·4) with ozanimod 1 mg (odds ratio 0·11, 95% CI 0·06-0·21; p<0·0001). Three serious adverse events unrelated to treatment were reported in patients assigned ozanimod 0·5 mg: optic neuritis, somatoform autonomic dysfunction, and cervical squamous metaplasia (HPV-related). No serious infectious or cardiac adverse events were reported, and no cases of macular oedema arose. The most common adverse events in the ozanimod 0·5 mg and 1 mg groups compared with placebo were nasopharyngitis (11 and five vs 12), headache (five and three vs eight), and urinary-tract infections (six and two vs two). The maximum reduction in mean heart rate by Holter monitoring during the first 6 h in ozanimod-treated participants was less than 2 beats per min (bpm) compared with baseline, with no patient having a minimum hourly heart rate less than 45 bpm. Electrocardiograms and 24-h Holter monitoring showed no increased incidence of atrioventricular block or sinus pause with ozanimod.

INTERPRETATION

Ozanimod significantly reduced MRI lesion activity in participants with relapsing multiple sclerosis, with a favourable safety profile over a period of 24 weeks. These findings warrant phase 3 trials, which are ongoing.

FUNDING

Receptos, Inc.

Therapy with natalizumab is associated with high JCV seroconversion and rising JCV index values

OBJECTIVE

The aim of the study was to analyze John Cunningham virus (JCV) serology in natalizumab-treated patients over time and assess whether they are influenced by natalizumab treatment.

METHODS

German (n = 1,921; 525 longitudinally) and French (n = 1,259; 711 longitudinally) patients were assessed for JCV serology alongside their therapy with natalizumab.

RESULTS

JCV serostatus changed in 69 of 525 longitudinally followed German patients (13.1%) over 14.8 months. Seroconversion according to serostatus was seen in 43 of 339 initially JCV- German patients (12.7% in 14.8 months; 10.3% per year) and 41 of 243 initially JCV- French patients (16.9% in 24 months; 8.5% per year). JCV index values could be reproduced (R (2) = 0.89) with the caveat of 8 of 50 samples (16%) being set into different risk categories between 2 assessments. Index values of JCV+ patients rose over time (p = 0.009) but not because of aging. Treatment with natalizumab was associated with a 15.9% increase of value in JCV+ patients in 14.8 months (12.9% per year).

CONCLUSIONS

JCV seroconversion and index values may be influenced by treatment with natalizumab. It is therefore important to monitor patients' JCV serology but also to incorporate additional risk factors into the progressive multifocal leukoencephalopathy risk stratification.

Next-Generation Therapeutics for IBD

Various novel drugs have recently been evaluated in clinical trials showing promising effects in patients with inflammatory bowel disease (IBD). Here, we summarize the recent literature in the area of emerging therapies in the field of IBD, with specific focus on anti-integrin antibodies, such as vedolizumab (anti-α4β7) and etrolizumab (anti-rhuMAb β7), and the Janus kinase (JAK) inhibitor tofacitinib. Moreover, we will discuss efficacy and safety data of golimumab (a new subcutaneous anti-tumor necrosis factor (TNF) antibody), Avaxia (an orally delivered anti-TNF antibody), and Budesonide MMX; all have been developed for the treatment of ulcerative colitis. Other therapeuticals that might find their way to the market the coming years include the anti-mucosal vascular addressin cell adhesion molecule (MAdCAM) PF-00547659, small molecules (including laquinimod and the CCR9 antagonist Vercirnon), as well as an orally active SMAD7 antisense oligonucleotide that showed clinical benefit in Crohn’s disease patients.

Exploring potential mechanisms of action of natalizumab in secondary progressive multiple sclerosis

Multiple sclerosis (MS) is a common and chronic central nervous system (CNS) demyelinating disease and a leading cause of permanent disability. Patients most often present with a relapsing-remitting disease course, typically progressing over time to a phase of relentless advancement in secondary progressive MS (SPMS), for which approved disease-modifying therapies are limited. In this review, we summarize the pathophysiological mechanisms involved in the development of SPMS and the rationale and clinical potential for natalizumab, which is currently approved for the treatment of relapsing forms of MS, to exert beneficial effects in reducing disease progression unrelated to relapses in SPMS. In both forms of MS, active brain-tissue injury is associated with inflammation; but in SPMS, the inflammatory response occurs at least partly behind the blood-brain barrier and is followed by a cascade of events, including persistent microglial activation that may lead to chronic demyelination and neurodegeneration associated with irreversible disability. In patients with relapsing forms of MS, natalizumab therapy is known to significantly reduce intrathecal inflammatory responses which results in reductions in brain lesions and brain atrophy as well as beneficial effects on clinical measures, such as reduced frequency and severity of relapse and reduced accumulation of disability. Natalizumab treatment also reduces levels of cerebrospinal fluid chemokines and other biomarkers of intrathecal inflammation, axonal damage and demyelination, and has demonstrated the ability to reduce innate immune activation and intrathecal immunoglobulin synthesis in patients with MS. The efficacy of natalizumab therapy in SPMS is currently being investigated in a randomized, double-blind, placebo-controlled trial.

Changes in brain atrophy indices in patients with relapsing-remitting multiple sclerosis treated with natalizumab

AIM

To evaluate the effect of natalizumab on progression of brain atrophy in multiple sclerosis (MS) patients and to search for a clinical or radiological marker of progression of brain atrophy.

PATIENTS AND METHODS

We retrospectively recorded demographic and clinical data, as well as the corpus callosum index (CCI) using MRI, in MS patients treated with natalizumab for 1-4 years.

RESULTS

In the study population (n = 29), baseline mean CCI was 0.37 ± 0.04 and final CCI 0.36 ± 0.04. 17 patients did not develop brain atrophy during follow-up. There was no statistically significant relationship between progression of atrophy and clinical and radiological parameters.

CONCLUSION

Natalizumab may have a neuroprotective effect.

Human mesenchymal stem cells target adhesion molecules and receptors involved in T cell extravasation

Introduction

Systemic delivery of bone marrow-derived mesenchymal stem cells (MSC) seems to be of benefit in the treatment of multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS) sustained by migration of T cells across the brain blood barrier (BBB) and subsequent induction of inflammatory lesions into CNS. MSC have been found to modulate several effector functions of T cells. In this study, we investigated the effects of MSC on adhesion molecules and receptors on T cell surface that sustain their transendothelial migration.

Methods

We used different co-culture methods combined with real-time PCR and flow cytometry to evaluate the expression both at the mRNA and at the plasma-membrane level of α4 integrin, β2 integrin, ICAM-1 and CXCR3. In parallel, we assessed if MSC are able to modulate expression of adhesion molecules on the endothelial cells that interact with T cells during their transendothelial migration.

Results

Our in vitro analyses revealed that MSC: (i) inhibit proliferation and activation of both peripheral blood mononuclear cells (PBMC) and CD3⁺-selected lymphocytes through the release of soluble factors; (ii) exert suppressive effects on those surface molecules highly expressed by activated lymphocytes and involved in transendothelial migration; (iii) inhibit CXCL10-driven chemotaxis of CD3⁺ cells; (iv) down-regulated expression of adhesion molecules on endothelial cells.

Conclusions

Taken together, these data demonstrate that the immunosuppressive effect of MSC does not exclusively depends on their anti-proliferative activity on T cells, but also on the impairment of leukocyte migratory potential through the inhibition of the adhesion molecules and receptors that are responsible for T cell trafficking across BBB. This could suggest a new mechanism through which MSC modulate T cell responses.

Biased signaling pathways via CXCR3 control the development and function of CD4+ T cell subsets

Structurally related chemotactic cytokines (chemokines) regulate cell trafficking through interactions with 7-transmembrane domain, G protein-coupled receptors. Biased signaling or functional selectivity is a concept that describes a situation where a 7-transmembrane domain receptor preferentially activates one of several available cellular signaling pathways. It can be divided into 3 distinct cases: ligand bias, receptor bias, and tissue or cell bias. Many studies, including those coming from our lab, have shown that only a limited number of chemokines are key drivers of inflammation. We have referred to them as "driver chemokines." They include the CXCR3 ligands CXCL9 and CXCL10, the CCR2 ligand CCL2, all 3 CCR5 ligands, and the CCR9 ligand CCL25. As for CXCR3, despite the proinflammatory nature of CXCL10 and CXCL9, transgenic mice lacking CXCR3 display an aggravated manifestation of different autoimmune disease, including Type I diabetes and experimental autoimmune encephalomyelitis. Recently, we showed that whereas CXCL9 and CXCL10 induce effector Th1/Th17 cells to promote inflammation, CXCL11, with a relatively higher binding affinity to CXCR3, drives the development of the forkhead box P3-negative IL-10(high) T regulatory 1 cell subset and hence, dampens inflammation. We also showed that CXCL9/CXCL10 activates a different signaling cascade than CXCL11, despite binding to the same receptor, CXCR3, which results in these diverse biologic activities. This provides new evidence for the role of biased signaling in regulating biologic activities, in which CXCL11 induces ligand bias at CXCR3 and receptor-biased signaling via atypical chemokine receptor 3.

Safety and Efficacy of AJM300, an Oral Antagonist of α4 Integrin, in Induction Therapy for Patients With Active Ulcerative Colitis

BACKGROUND & AIMS

AJM300 is an orally active small-molecule antagonist of the α4 integrin subunit. We performed a randomized trial to investigate the efficacy and safety of AJM300 in patients with active ulcerative colitis (UC).

METHODS

In a double-blind, placebo-controlled, phase 2a study, 102 patients with moderately active UC (Mayo Clinic scores of 6-10, endoscopic subscores ≥2, and rectal bleeding subscores ≥1) who had inadequate response or intolerance to mesalamine or corticosteroids were randomly assigned to receive AJM300 (960 mg) or placebo 3 times daily for 8 weeks. The primary end point was a clinical response at week 8, defined as a decrease in Mayo Clinic score of at least 3 points and a decrease of at least 30% from baseline, with a decrease in the rectal bleeding subscore of at least 1 point or an absolute rectal bleeding subscore of 0 or 1.

RESULTS

Clinical response rates were 62.7% and 25.5% at week 8 in the AJM300 group and placebo group, respectively (odds ratio [OR] = 5.35; 95% confidence interval [CI]: 2.23-12.82; P = .0002). Rates of clinical remission (Mayo Clinic score ≤2 and no subscore >1) were 23.5% and 3.9% in the AJM300 group and placebo groups, respectively (OR = 7.81; 95% CI: 1.64-37.24; P = .0099), and rates of mucosal healing (endoscopic subscores of 0 or 1) were 58.8% and 29.4% (OR = 4.65; 95% CI: 1.81-11.90; P = .0014). No serious adverse event, including progressive multifocal leukoencephalopathy, was observed, although more investigations are needed to confirm the safety profile of this drug.

CONCLUSIONS

AJM300 was well tolerated and more effective than placebo in inducing clinical response, clinical remission, and mucosal healing in patients with moderately active UC. ClinicalTrials.jp no: JapicCTI-132293.

Hepatic manifestations of non-steroidal inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is composed of Crohn’s disease and ulcerative colitis and is manifested by both bowel-related and extraintestinal manifestations. Recently the number of therapeutic options available to treat IBD has dramatically increased, with each new medication having its own mechanism of action and side effect profile. A complete understanding of the hepatotoxicity of these medications is important in order to distinguish these complications from the hepatic manifestations of IBD. This review seeks to evaluate the hepatobiliary complications of non-steroid based IBD medications and aide providers in the recognition and management of these side-effects.

Monoclonal antibody therapies for the treatment of relapsing-remitting multiple sclerosis: differentiating mechanisms and clinical outcomes

Monoclonal antibody (mAb) therapies for relapsing-remitting multiple sclerosis (MS) target immune cells or other molecules involved in pathogenic pathways with extraordinary specificity. Natalizumab and alemtuzumab are the only two currently approved mAbs for the treatment of MS, having demonstrated significant reduction in clinical and magnetic resonance imaging disease activity and disability in clinical studies. Ocrelizumab and daclizumab are in the late stages of phase III trials, and several other mAbs are in the early stages of clinical evaluation. mAbs have distinct structural characteristics (e.g. chimeric, humanized, fully human) and unique targets (e.g. blocking interactions, induction of signal transduction by receptor binding, complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity) conferring different mechanisms of action in MS. Because of these differences, mAbs for MS do not constitute a single treatment class; each must be considered individually when selecting appropriate therapy. Furthermore, in reviewing the data from clinical studies of mAbs, attention should be drawn to use of different comparators (e.g. placebo or interferon β-1a) and study designs. Each mAb treatment has a unique administration schedule. In the decision to select the appropriate treatment for each individual MS patient, careful review of the benefits relative to risks of mAbs is balanced against the risk of development of MS-associated disability.

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.

Sjögren's syndrome associated dry eye in a mouse model is ameliorated by topical application of integrin α4 antagonist GW559090

Sjögren's syndrome is an autoimmune disease associated with inflammation of exocrine glands with clinical manifestations of dry eye and dry mouth. Dry eye in this disease involves inflammation of the ocular surface tissues - cornea and conjunctiva. While systemic blockade of adhesion molecules has been used to treat autoimmune diseases, the purpose of this study was to determine the therapeutic efficacy of topical application of an integrin α4 adhesion molecule antagonist in a mouse model of dry eye associated with Sjögren's syndrome. To assess this spontaneously developed ocular surface inflammation related to Sjögren's syndrome in TSP-1null mice (12 wks) was evaluated. Mice were treated with topical formulations containing 0.1% dexamethasone or 30 mg/ml GW559090 or vehicle control. Corneal fluorescein staining and conjunctival goblet cell density were assessed. Real-time PCR analysis was performed to assess expression of the inflammatory marker IL-1β in the cornea and Tbet and RORγt in the draining lymph nodes. Ocular surface inflammation was detectable in TSP-1null mice (≥12 wk old), which resulted in increased corneal fluorescein staining indicative of corneal barrier disruption and reduced conjunctival goblet cell density. These changes were accompanied by increased corneal expression of IL-1β as compared to WT controls and an altered balance of Th1 (Tbet) and Th17 (RORγt) markers in the draining lymph nodes. Topically applied dexamethasone and GW559090 significantly reduced corneal fluorescein staining compared to vehicle treatment (p = 0.023 and p < 0.001, respectively). This improved corneal barrier integrity upon adhesion molecule blockade was consistent with significantly reduced corneal expression of pro-inflammatory IL-1β compared to vehicle treated groups (p < 0.05 for both treatments). Significant improvement in goblet cell density was also noted in mice treated with 0.1% dexamethasone and GW559090 (p < 0.05 for both). We conclude that similar to topical dexamethasone, topically administered GW559090 successfully improved corneal barrier integrity and inflammation in an established ocular surface disease associated with Sjögren's syndrome.

PML risk stratification using anti-JCV antibody index and L-selectin

Background:

Natalizumab treatment is associated with progressive multifocal leukoencephalopathy (PML) development. Treatment duration, prior immunosuppressant use, and JCV serostatus are currently used for risk stratification, but PML incidence stays high. Anti-JCV antibody index and L-selectin (CD62L) have been proposed as additional risk stratification parameters.

Objective:

This study aimed at verifying and integrating both parameters into one algorithm for risk stratification.

Methods:

Multicentric, international cohorts of natalizumab-treated MS patients were assessed for JCV index (1921 control patients and nine pre-PML patients) and CD62L (1410 control patients and 17 pre-PML patients).

Results:

CD62L values correlate with JCV serostatus, as well as JCV index values. Low CD62L in natalizumab-treated patients was confirmed and validated as a biomarker for PML risk with the risk factor “CD62L low” increasing a patient’s relative risk 55-fold ( p < 0.0001). Validation efforts established 86% sensitivity/91% specificity for CD62L and 100% sensitivity/59% specificity for JCV index as predictors of PML. Using both parameters identified 1.9% of natalizumab-treated patients in the reference center as the risk group.

Conclusions:

Both JCV index and CD62L have merit for risk stratification and share a potential biological relationship with implications for general PML etiology. A risk algorithm incorporating both biomarkers could strongly reduce PML incidence.

An update on immunopathogenesis, diagnosis, and treatment of multiple sclerosis

BACKGROUND

Multiple sclerosis is an acquired demyelinating disease of the central nervous system. It is the second most common cause of disability in adults in United States after head trauma.

DISCUSSION

The etiology of MS is probably multifactorial, related to genetic, environmental, and several other factors. The pathogenesis is not fully understood but is believed to involve T-cell-mediated inflammation directed against myelin and other related proteins with a possible role for B cells. The McDonald criteria have been proposed and revised over the years to guide the diagnosis of MS and are based on clinical presentation and magnetic resonance imaging (MRI) of the brain and spinal cord to establish dissemination in time and space. The treatment of MS includes disease modification with immunomodulator drugs and symptom management to address the specific symptoms such as fatigue, spasticity, and pain.

CONCLUSION

An update on etiology, pathogenesis, diagnosis, and immunomodulatory treatment of MS is presented.

Brain-peripheral cell crosstalk in white matter damage and repair

White matter damage is an important part of cerebrovascular disease and may be a significant contributing factor in vascular mechanisms of cognitive dysfunction and dementia. It is well accepted that white matter homeostasis involves multifactorial interactions between all cells in the axon-glia-vascular unit. But more recently, it has been proposed that beyond cell-cell signaling within the brain per se, dynamic crosstalk between brain and systemic responses such as circulating immune cells and stem/progenitor cells may also be important. In this review, we explore the hypothesis that peripheral cells contribute to damage and repair after white matter damage. Depending on timing, phenotype and context, monocyte/macrophage can possess both detrimental and beneficial effects on oligodendrogenesis and white matter remodeling. Endothelial progenitor cells (EPCs) can be activated after CNS injury and the response may also influence white matter repair process. These emerging findings support the hypothesis that peripheral-derived cells can be both detrimental or beneficial in white matter pathology in cerebrovascular disease. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia, edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.

Assessment of immune functions and MRI disease activity in relapsing-remitting multiple sclerosis patients switching from natalizumab to fingolimod (ToFingo-Successor)

BACKGROUND

In light of the increased risk of progressive multifocal encephalopathy (PML) development under long-term treatment with the monoclonal antibody natalizumab which is approved for treatment of active relapsing remitting multiple sclerosis (RRMS), there is a clear need for alternative treatment options with comparable efficacy and reduced PML risk. One such option is fingolimod, a functional sphingosin-1-receptor antagonist that has been approved as first oral drug for treatment of active RRMS. However, the optimal switching design in terms of prevention of disease reoccurrence is still unknown. Moreover, potential additive effects of both drugs on immune functions, especially with regard to migration, have not yet been evaluated.

METHODS/DESIGN

This is an exploratory, open-label, monocentric, investigator-initiated clinical trial. Fifteen RRMS patients under stable treatment with natalizumab will receive one last natalizumab infusion followed by a wash-out period of 8 weeks before fingolimod treatment initiation for a period of 24 weeks. Disease activity under natalizumab and during switching will be closely monitored by assessment of relapse rate and disease severity as well as high-frequent high-resolution magnetic resonance imaging including quantitative diffusion tensor imaging. Immunological assays include longitudinal assessment of adhesion molecule expression, functional evaluation of the migratory capacity of immune cells in an in-vitro model of the blood-brain-barrier, and the quality of cellular antiviral immune responses.

DISCUSSION

Our trial represents the first detailed and longitudinal functional analysis of key immunological parameters in the process of switching from natalizumab and fingolimod, especially with regard to potential additive effects of both drugs on trafficking and immune surveillance. Moreover, our study will generate valuable information about even subtle disease exacerbations as consequence of natalizumab cessation, which will help to understand whether a switching protocol containing a wash-out period of 8 weeks before fingolimod treatment is appropriate in terms of disease stability.

Biotherapies targeting T and B cells: from immune suppression to immune tolerance

The field of immunotherapy has undergone a major rejuvenation with the development of monoclonal antibodies and fusion proteins targeting specialized receptors of T and B lymphocytes or cytokines relevant for the differentiation of these cells. This review will focus on autoimmunity, probably the field that benefited most from these new biological therapies that very significantly impacted the modalities of patient's care. The aim is to present the agents which constitute major disease modifying drugs for the treatment of chronic invalidating autoimmune diseases. In doing so, we shall distinguish between agents that globally depress immune responses and those that may selectively target the harmful autoimmune response over long-term while preserving the capacity of the host to react normally to exogenous antigens, in other words, agents promoting 'operational tolerance'.

Lack of ceramide synthase 2 suppresses the development of experimental autoimmune encephalomyelitis by impairing the migratory capacity of neutrophils

Ceramide synthases (CerS) synthesise ceramides of defined acyl chain lengths, which are thought to mediate cellular processes in a chain length-dependent manner. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we observed a significant elevation of CerS2 and its products, C24-ceramides, in CD11b(+) cells (monocytes and neutrophils) isolated from blood. This result correlates with the clinical finding that CerS2 mRNA expression and C24-ceramide levels were significantly increased by 2.2- and 1.5-fold, respectively, in white blood cells of MS patients. The increased CerS2 mRNA/C24-ceramide expression in neutrophils/monocytes seems to mediate pro-inflammatory effects, since a specific genetic deletion of CerS2 in blood cells or a total genetic deletion of CerS2 significantly delayed the onset of clinical symptoms, due to a reduced infiltration of immune cells, in particular neutrophils, into the central nervous system. CXCR2 chemokine receptors, expressed on neutrophils, promote the migration of neutrophils into the central nervous system, which is a prerequisite for the recruitment of further immune cells and the inflammatory process that leads to the development of MS. Interestingly, neutrophils isolated from CerS2 null EAE mice, as opposed to WT EAE mice, were characterised by significantly lower CXCR2 receptor mRNA expression resulting in their reduced migratory capacity towards CXCL2. Most importantly, G-CSF-induced CXCR2 expression was significantly reduced in CerS2 null neutrophils and their migratory capacity was significantly impaired. In conclusion, our data strongly indicate that G-CSF-induced CXCR2 expression is regulated in a CerS2-dependent manner and that CerS2 thereby promotes the migration of neutrophils, thus, contributing to inflammation and the development of EAE and MS.

Multiple sclerosis in older adults: the clinical profile and impact of interferon Beta treatment

Background. We examined (1) patient characteristics and disease-modifying drug (DMD) exposure in late-onset (LOMS, ≥50 years at symptom onset) versus adult-onset (AOMS, 18–<50 years) MS and (2) the association between interferon-beta (IFNβ) and disability progression in older relapsing-onset MS adults (≥50 years). Methods. This retrospective study (1980–2004, British Columbia, Canada) included 358 LOMS and 5627 AOMS patients. IFNβ-treated relapsing-onset MS patients aged ≥50 (regardless of onset age, 90) were compared with 171 contemporary and 106 historical controls. Times to EDSS 6 from onset and from IFNβ eligibility were examined using survival analyses. Results. LOMS patients (6%) were more likely to be male, with motor onset and a primary-progressive course, and exhibit faster progression and were less likely to take DMDs. Nonetheless, 57% were relapsing-onset, of which 31% were prescribed DMDs, most commonly IFNβ. Among older relapsing-onset MS adults, no significant association between IFNβ exposure and disability progression was found when either the contemporary (hazard ratio [HR]: 0.46; 95% CI: 0.18–1.22) or historical controls (HR: 0.54; 95% CI: 0.20–1.42) were considered. Conclusion. LOMS differed clinically from AOMS. One-third of older relapsing-onset MS patients were prescribed a DMD. IFNβ exposure was not significantly associated with reduced disability in older MS patients.