Progressive Multiple Sclerosis Trials Research Articles

Spinal cord atrophy as a primary outcome measure in phase II trials of progressive multiple sclerosis

Objectives: To measure the development of spinal cord (SC) atrophy over 1 year in patients with progressive multiple sclerosis (PMS) and determine the sample sizes required to demonstrate a reduction in spinal cord cross-sectional area (SC-CSA) as an outcome measure in clinical trials. Methods: In total, 44 PMS patients (26 primary progressive multiple sclerosis (PPMS), 18 secondary progressive multiple sclerosis (SPMS)) and 29 healthy controls (HCs) were studied at baseline and 12 months. SC-CSA was measured using the three-dimensional (3D) fast field echo sequences acquired at 3T and the active surface model. Multiple linear regressions were used to investigate changes in imaging measurements. Results: PPMS patients had shorter disease duration, lower Expanded Disability Status Scale (EDSS) and larger SC-CSA than SPMS patients. All patients together showed a significantly greater decrease in percentage SC-CSA change than HCs, which was driven by the PPMS. All patients deteriorated over 1 year, but no association was found between percentage SC-CSA change and clinical changes. The sample size per arm required to detect a 50% treatment effect over 1 year, at 80% power, was 57 for PPMS and 546 for SPMS. Conclusion: SC-CSA may become an outcome measure in trials of PPMS patients, when they are at an early stage of the disease, have moderate disability and modest SC atrophy.

Multiple sclerosis in 2016: Immune-directed therapies in MS - efficacy and limitations.

In 2016, new highly active treatment options for relapsing–remitting multiple sclerosis (MS) emerged. At the same time, large clinical trials in progressive MS highlighted the limitations of immune-directed therapies, and called for new strategies to treat disease progression in MS.

Progressive multiple sclerosis: from pathogenic mechanisms to treatment.

During the past decades, better understanding of relapsing-remitting multiple sclerosis disease mechanisms have led to the development of several disease-modifying therapies, reducing relapse rates and severity, through immune system modulation or suppression. In contrast, current therapeutic options for progressive multiple sclerosis remain comparatively disappointing and challenging. One possible explanation is a lack of understanding of pathogenic mechanisms driving progressive multiple sclerosis. Furthermore, diagnosis is usually retrospective, based on history of gradual neurological worsening with or without occasional relapses, minor remissions or plateaus. In addition, imaging methods as well as biomarkers are not well established. Magnetic resonance imaging studies in progressive multiple sclerosis show decreased blood-brain barrier permeability, probably reflecting compartmentalization of inflammation behind a relatively intact blood-brain barrier. Interestingly, a spectrum of inflammatory cell types infiltrates the leptomeninges during subpial cortical demyelination. Indeed, recent magnetic resonance imaging studies show leptomeningeal contrast enhancement in subjects with progressive multiple sclerosis, possibly representing an in vivo marker of inflammation associated to subpial demyelination. Treatments for progressive disease depend on underlying mechanisms causing central nervous system damage. Immunity sheltered behind an intact blood-brain barrier, energy failure, and membrane channel dysfunction may be key processes in progressive disease. Interfering with these mechanisms may provide neuroprotection and prevent disability progression, while potentially restoring activity and conduction along damaged axons by repairing myelin. Although most previous clinical trials in progressive multiple sclerosis have yielded disappointing results, important lessons have been learnt, improving the design of novel ones. This review discusses mechanisms involved in progressive multiple sclerosis, correlations between histopathology and magnetic resonance imaging studies, along with possible new therapeutic approaches.

Development of a Sensitive Outcome for Economical Drug Screening for Progressive Multiple Sclerosis Treatment.

Therapeutic advance in progressive multiple sclerosis (MS) has been very slow. Based on the transformative role magnetic resonance imaging (MRI) contrast-enhancing lesions had on drug development for relapsing-remitting MS, we consider the lack of sensitive outcomes to be the greatest barrier for developing new treatments for progressive MS. The purpose of this study was to compare 58 prospectively acquired candidate outcomes in the real-world situation of progressive MS trials to select and validate the best-performing outcome. The 1-year pre-treatment period of adaptively designed IPPoMS (ClinicalTrials.gov #NCT00950248) and RIVITaLISe (ClinicalTrials.gov #NCT01212094) Phase II trials served to determine the primary outcome for the subsequent blinded treatment phase by comparing 8 clinical, 1 electrophysiological, 1 optical coherence tomography, 7 MRI volumetric, 9 quantitative T1 MRI, and 32 diffusion tensor imaging MRI outcomes. Fifteen outcomes demonstrated significant progression over 1 year (Δ) in the predetermined analysis and seven out of these were validated in two independent cohorts. Validated MRI outcomes had limited correlations with clinical scales, relatively poor signal-to-noise ratios (SNR) and recorded overlapping values between healthy subjects and MS patients with moderate-severe disability. Clinical measures correlated better, even though each reflects a somewhat different disability domain. Therefore, using machine-learning techniques, we developed a combinatorial weight-adjusted disability score (CombiWISE) that integrates four clinical scales: expanded disability status scale (EDSS), Scripps neurological rating scale, 25 foot walk and 9 hole peg test. CombiWISE outperformed all clinical scales (Δ = 9.10%; p = 0.0003) and all MRI outcomes. CombiWISE recorded no overlapping values between healthy subjects and disabled MS patients, had high SNR, and predicted changes in EDSS in a longitudinal assessment of 98 progressive MS patients and in a cross-sectional cohort of 303 untreated subjects. One point change in EDSS corresponds on average to 7.50 point change in CombiWISE with a standard error of 0.10. The novel validated clinical outcome, CombiWISE, outperforms the current broadly utilized MRI brain atrophy outcome and more than doubles sensitivity in detecting clinical deterioration in progressive MS in comparison to the scale traditionally used for regulatory approval, EDSS.

Design, rationale, and baseline characteristics of the randomized double-blind phase II clinical trial of ibudilast in progressive multiple sclerosis

BackgroundPrimary and secondary progressive multiple sclerosis (MS), collectively called progressive multiple sclerosis (PMS), is characterized by gradual progression of disability. The current anti-inflammatory treatments for MS have little or no efficacy in PMS in the absence of obvious active inflammation. Optimal biomarkers for phase II PMS trials is unknown. Ibudilast is an inhibitor of macrophage migration inhibitor factor and phosphodiesterases-4 and −10 and exhibits possible neuroprotective properties. The goals of SPRINT-MS study are to evaluate the safety and efficacy of ibudilast in PMS and to directly compare several imaging metrics for utility in PMS trials. MethodsSPRINT-MS is a randomized, placebo-controlled, phase II trial of ibudilast in patients with PMS. Eligible subjects were randomized 1:1 to receive either ibudilast (100mg/day) or placebo for 96weeks. Imaging is conducted every 24weeks for whole brain atrophy, magnetization transfer ratio, diffusion tensor imaging, cortical brain atrophy, and retinal nerve fiber layer thickness. Clinical outcomes include neurologic disability and patient reported quality of life. Safety assessments include laboratory testing, electrocardiography, and suicidality screening. ResultsA total of 331 subjects were enrolled, of which 255 were randomized onto active study treatment. Randomized subjects were 53.7% female and mean age 55.7 (SD 7.3) years. The last subject is projected to complete the study in May 2017. ConclusionSPRINT-MS is designed to evaluate the safety and efficacy of ibudilast as a treatment for PMS while simultaneously validating five different imaging biomarkers as outcome metrics for use in future phase II proof-of-concept PMS trials.

Progressive multiple sclerosis.

The purpose of this study is to highlight the pathological features and clinical aspects of progressive multiple sclerosis (PMS) and also the results of clinical trial experience to date and review ongoing clinical trials and prospective new treatment options. This study will explain the challenges of clinical trial design in PMS. Multiple sclerosis (MS) has been identified as a chronic immune mediated disease, and the progressive phase of the disease appears to have significant neurodegenerative mechanisms. The classification of the course of PMS has been reorganized into categories of active vs. inactive inflammatory disease and the presence vs. absence of gradual disease progression. This differentiation allows clearer conceptualization of PMS and possibly even more efficient recruitment of PMS patients into clinical trials. Clinical trial experience to date in PMS has been negative with anti-inflammatory medications used in relapsing MS. Simvastatin was recently tested in a phase II trial and showed a 43% reduction of annualized atrophy progression in secondary progressive MS. Ongoing PMS trials are currently being conducted with the phosphodiesterase inhibitor ibudilast, S1P modulator siponimod and anti-B-cell therapy ocrelizumab. Several efforts for development of outcome measures in PMS are ongoing. PMS represents a significant challenge, as the pathogenesis of the disease is not well understood, no validated outcome metrics have been established and clinical trial experience to date has been disappointing. Advances in the understanding of the disease and lessons learned in previous clinical trials are paving the way for successful development of disease-modifying agents for this disease.

In Vivo Detection of Diffuse Inflammation in Secondary Progressive Multiple Sclerosis Using PET Imaging and the Radioligand 11C-PK11195

Patients with secondary progressive multiple sclerosis (SPMS) are lacking efficient medication to slow down the progression of their disease. PET imaging holds promise as a method to study, at the molecular level and in vivo, the central nervous system pathology of SPMS. PET might thus help to elucidate potential therapeutic targets and be useful as an imaging biomarker in future treatment trials of progressive multiple sclerosis. The objective of this study was to evaluate whether translocator protein (TSPO) imaging could be used to visualize the diffuse inflammation located in the periplaque area and in the normal-appearing white matter (NAWM) in the brains of patients with SPMS. This was an imaging study using MR imaging and PET with (11)C-PK11195 binding to TSPO, which is expressed in activated, but not in resting, microglia. Ten SPMS patients with a mean expanded disability status scale score of 6.3 (SD, 1.5) and eight age-matched healthy controls were studied. The imaging was performed using High-Resolution Research Tomograph PET and 1.5-T MR imaging scanners. Microglial activation was evaluated as the distribution volume ratio (DVR) of (11)C-PK11195 from dynamic PET images. DVR estimations were performed with special interest in NAWM and gray matter using region-of-interest and parametric image-based approaches. The DVR of (11)C-PK11195 was significantly increased in the periventricular and total NAWM (P = 0.016 and P < 0.001, respectively) and in the thalamic ROIs (P = 0.027) of SPMS patients, compared with the control group. Similarly, parametric image analysis showed widespread increases of (11)C-PK11195 in the white matter of SPMS patients, compared with healthy controls. Increased perilesional TSPO uptake was present in 57% of the chronic T1 lesions in MR imaging. The finding of increased (11)C-PK11195 binding in the NAWM of SPMS patients is in line with the neuropathologic demonstration that activated microglial cells are the source of diffuse NAWM inflammation. Evaluating microglial activation with TSPO-binding PET ligands provides a unique tool to assess diffuse brain inflammation and perilesional activity in progressive multiple sclerosis in vivo.

Treatment trials in progressive MS—current challenges and future directions

The introduction of immunomodulatory treatments has transformed the management of patients with relapsing-remitting multiple sclerosis (MS), but has had no consistent benefit in progressive MS. Patients with primary or secondary progressive MS, therefore, are faced with relentless functional decline that remains without treatment. Clinical trials in progressive MS are clearly needed, but their design and conduct is challenging, and different from that of trials in relapsing-remitting MS. Challenges to reliable measurement of clinical progression, uncertainties about the natural history of progressive MS, and the unclear role of imaging outcomes all impede optimal trial design. Clinical trials in progressive MS have used time to a predefined change on the Expanded Disability Status Scale as their main outcome measure, which has had important consequences for trial duration and has led to inclusion of only a highly selected minority of patients. Here, we review the current approach to clinical trial design in progressive MS, outline key ongoing challenges, and suggest strategies to overcome such hurdles.

Humoral-targeted immunotherapies in multiple sclerosis.

The continuous improvements of our understanding of the pathophysiological changes that occur in multiple sclerosis (MS) have translated into many novel therapeutic agents at different stages of development. These agents target more specifically the innate or the adaptive immune response. We will review agents available or under development that target the humoral pathways of the adaptive immune response. As such, humoral targeted immunotherapies that are being developed for MS are discussed herein: rituximab, ocrelizumab, and ofatumumab show promise as B-cell depleting agents. Other agents, such as atacicept were suspended during development in MS due to increased inflammatory activity versus the placebo. Although most agents were tested in relapsing-remitting forms of MS, rituximab and ocrelizumab have both been studied in progressive MS, whereas ocrelizumab only is currently moving forward in primary progressive MS trials. We provide an overview of agents available and under development that target the humoral response and include their mechanisms of action, safety profiles, and results of clinical trials.

Refinement of the Clinical Scenario Evaluation Framework for Assessment of Competing Development Strategies with an Application to Multiple Sclerosis

When competing strategies for development programs, clinical trial designs, or data analysis methods exist, the alternatives need to be evaluated in a systematic way to facilitate informed decision making. Here we describe a refinement of the recently proposed clinical scenario evaluation framework for the assessment of competing strategies. The refinement is achieved by subdividing key elements previously proposed into new categories, distinguishing between quantities that can be estimated from preexisting data and those that cannot and between aspects under the control of the decision maker from those that are determined by external constraints. The refined framework is illustrated by an application to a design project for an adaptive seamless design for a clinical trial in progressive multiple sclerosis.

A longitudinal study of MRI-detected atrophy in secondary progressive multiple sclerosis

MRI measures of tissue atrophy within the central nervous system may reflect the neurodegenerative process which underpins the progressive phase of multiple sclerosis (MS). There has been limited longitudinal investigation of MRI-detected atrophy in secondary progressive MS. This study includes 56 subjects with secondary progressive MS. Subjects were followed up for 2 years and MRI analysis was conducted at 12 month intervals using the following measures: (1) whole brain (WB) volume change; (2) grey and white matter (WM) volumes; (3) central brain volume; (4) upper cervical spinal cord (SC) area; (5) T2 lesion volumes. Clinical measures included the Expanded Disability Status Scale and the MS Functional Composite. All volumetric MRI measures were assessed for sensitivity, responsiveness, reliability and correlation with disability. The mean annual atrophy rate of WB was 0.59% per year and this was the most responsive atrophy measure assessed. Grey matter (GM) atrophy (-1.18% per year) was greater and more responsive than WM atrophy (0.12% per year). The SC demonstrated the highest atrophy rate at 1.63% per year. WB, GM and SC atrophy all correlated with change in the Multiple Sclerosis Functional Composite z score (r = 0.35, 0.42, 0.34), and GM atrophy was the only correlate of change in the 9 Hole Peg Test and Paced Auditory Serial Addition Test performance. None of the MRI measures correlated with Expanded Disability Status Score progression. Measures of WB, GM and SC atrophy all have attributes for use as surrogate markers in secondary progressive MS trials and improvement in the reliability of the GM and SC volume measurements may enhance these further.

Multiple sclerosis therapeutics

In this essay, we draw attention to some recent downsides and surprises of multiple sclerosis (MS) therapeutics. These include experiences with recent head-to-head trials of interferon-beta and glatiramer acetate, dose escalation trials, frustrating efforts with progressive MS trials, failures of smart concepts and designer therapies, and harsh lessons from newly observed adverse reactions.

MRI as an outcome in multiple sclerosis clinical trials

T2-weighted and gadolinium enhanced T1-weighted MRI scans measure plaque burden and breakdown of the blood-brain barrier, respectively, in multiple sclerosis (MS) lesions. These have become widely used outcome measures for monitoring disease activity in clinical trials and clinical practice. However, their use as surrogates or biomarkers for disability and relapses, key clinical outcome measures, has remained incompletely validated. In a clinical trial database comprised of 31 relapsing-remitting and secondary progressive MS trial placebo groups, we assessed relationships between 1) T2 lesion load (TLL) change and disability change and 2) gadolinium enhancement of MS lesions and on-study relapses with univariate and multivariate analyses. In relapsing-remitting MS, TLL change (n = 223) made no independent contribution to predicting change in disability from baseline to trials' end. Similarly, inclusion of gadolinium enhancing lesions (n = 170) into multivariate models did not independently contribute to the predictive value for on-trial relapses. In secondary progressive MS, a small effect of TLL was found for disability change (n = 355) but in multivariate analysis this accounted for less than 5% of the variance in end-of-trial disability. Results were replicated in independent datasets, more than doubling effective sample sizes. MRI measures widely used in trials of relapsing-remitting and progressive multiple sclerosis add little if anything independently to the clinically relevant relapse and disability outcomes. These results reemphasize the importance of validating potential surrogate markers against clinical measures and highlight the need for better MRI markers of disease activity and progression.

Dirucotide (MBP8298) for the treatment of multiple sclerosis

Multiple sclerosis (MS) is a chronic and debilitating disease affecting approximately 2.5 million people worldwide, and safe and effective treatment options are sorely lacking. While there are several currently approved drugs that have shown some efficacy at reducing the relapse rate in patients with the relapsing–remitting form of the disease, the impact of this outcome relative to long-term disease progression is unknown. Effective treatment for those with primary or secondary progressive MS is practically nonexistent. Dirucotide (MBP8298) is a synthetic peptide that has shown promise at increasing time to progression with little or no associated toxicity in Phase II studies. The drug is specifically designed to induce tolerance in patients with HLA types DR2 and/or DR4, although patients with other HLA subtypes may also benefit. Dirucotide is now being evaluated in two large Phase III secondary progressive MS trials, as well as a smaller Phase II relapsing–remitting MS trial.

Disability as an outcome in MS clinical trials

Inferences about long-term effects of therapies in multiple sclerosis (MS) have been based on surrogate markers studied in short-term trials. Preventing progressive disability is the key therapeutic goal but there remains no validated definition for its measurement in a trial context. Meanwhile, MS trials continue to shorten and to depend on unvalidated surrogates. Since there have been no treatment claims for improving unremitting disability, worsening of disability in the placebo/control arm must occur for effectiveness on this outcome to be shown. We examined widely-used clinical surrogates of long-term disability progression in individual patients with MS within a unique database from the placebo arms of 31 randomized clinical trials. Detection of treatment effects in secondary progressive MS trials is undermined by noise in disability measurement. Whereas existing measures can be partially validated in secondary progressive MS, this is not the case in relapsing-remitting MS. Here, examination of widely used definitions of treatment failure demonstrated that disability progression was no more likely than similarly defined improvement. Existing definitions of disease progression in short-term intervention trials in relapsing-remitting patients reflect random variation, measurement error, and remitting relapses. Clinical surrogates of unremitting disability used in trials of relapsing-remitting multiple sclerosis cannot be validated. Trials have been too short or degrees of disability change too small to measure the key outcomes. These analyses highlight the difficulty in determining effectiveness of therapy in chronic diseases.

The natural history of multiple sclerosis: a geographically based study. 6. Applications to planning and interpretation of clinical therapeutic trials in primary progressive multiple sclerosis.

The natural history of primary progressive multiple sclerosis (PP-multiple sclerosis) recently has been defined in a geographically based multiple sclerosis population. For a series of prognostically defined hypothetical entry criteria based upon current trends in presentation to the London Multiple Sclerosis Clinic, we determined the number of patients who would have been trial eligible. Using 23 year mean longitudinal natural history data, we identified the observed rate of deterioration for frequently used trial endpoints. Hypothetical entry criteria were based on the practical considerations which would attend the execution of clinical trials in progressive multiple sclerosis. We then developed a series of sample size tables giving the number of patients with PP-multiple sclerosis and the length of observation that would be required to detect a significant result (P = 0.05) for a 25, 50 and 75% decrease in the median time to progression with 80 or 90% power, with treatment efficacy based upon the ability to slow progression on the disability status score. It is expected that the considerations outlined here will prove useful for both trial design and interpretation of trials in PP-multiple sclerosis which will require multi-centre collaborative efforts.

Long-term and short-term outcome of multiple sclerosis: a 3-year follow-up study.

The anticipated rate of short-term worsening of disability scores is the basis of power estimations in clinical trials of progressive multiple sclerosis (MS). While the clinician is most concerned in modifying the long-term outcome (eg, time to reach the Expanded Disability Status Scale [EDSS]6), the end points studied in clinical trials are those describing short-term outcome (eg, worsening of EDSS scores over 1 to 3 years). However, short-term outcome of MS may not be correlated with long-term outcome. To validate previously published models predicting time to EDSS 6. To establish predictors of short-term outcome of MS. The Ottawa, Ontario, Regional Multiple Sclerosis Clinic. Two hundred fifty-nine patients were followed up prospectively by a single neurologist. Actuarial analysis of time to reach EDSS 6 and change in EDSS scores over a follow-up period of 1 to 3 years. The long-term outcome in the Ottawa population was more favorable than published data from London, Ontario. Predictions of time to EDSS 6 were not strongly correlated with the degree of short-term worsening over the follow-up period. Parameters associated with a higher probability of short-term worsening were proximity of the baseline EDSS score to 4.5 and duration of MS less than 20 years. Baseline EDSS and duration of MS must be considered in the design of clinical trials of progressive MS.