Trials In Primary Progressive Multiple Sclerosis Research Articles

Threshold definitions for significant change on the timed 25-foot walk and nine-hole peg test in primary progressive multiple sclerosis.

The timed 25-foot walk (T25FW) and nine-hole peg test (NHPT) exhibit random variability in the short term. A threshold of ≥20% change from baseline has been used to indicate true disability change, but other threshold definitions may be better suited to exclude false and include true change events. The aim of this study was to use patient-level original trial data to investigate the short-term variation in T25FW and NHPT, and to compare its extent with disability change at 12-month follow-up in people with primary progressive multiple sclerosis (PPMS). We used original patient-level data from PROMISE, a large PPMS trial. In this trial, three separate T25FW and NHPT measurements were performed 1 week apart during screening. We used these repeated measures to describe the extent of short-term variation. We used binary logistic regression models to investigate the association between screening characteristics and unacceptable short-term variation. The traditional 20% threshold excluded a reasonable number of false change events, while also yielding a large number of change events at follow-up. Increasing index values on the T25FW and NHPT were associated with higher short-term variation. The traditional ≥20% change threshold for the T25FW and NHPT represents a reasonable compromise between reducing the number of false change events and achieving the largest number of change events in people with PPMS. Our analyses inform the design of clinical trials in PPMS.

Electrophysiological markers and predictors of the disease course in primary progressive multiple sclerosis

Background: Currently no valid surrogate marker exists for primary progressive multiple sclerosis (PPMS). Objective: Our aim was to prospectively investigate multimodal evoked potentials (EPs) as markers and predictors of the disease course in PPMS. Methods: Twenty-two PPMS patients were prospectively examined with visual, somatosensory and motor EPs and Expanded Disability Status Scale (EDSS) assessments at baseline (T0) and at six-month intervals over three years. Spearman rank correlation was used to determine the relationship between EP measures and EDSS. The relationship between disease evolution and a numerical score derived from z-transformed EP-latencies (s-EP-Q) and baseline characteristics was further assessed using multivariable linear regression analysis. Results: s-EP-Q correlated with EDSS score at all points in time in cross-sectional comparison (0.53≤rs ≤0.68; 0.0007≤p≤0.0232) and also longitudinally by trend (rs=0.46, p=0.0740). The s-EP-QT0 correlated with the EDSS score at year 3 (T6) (rs=0.77, p<0.0001). The s-EP-Q changes became statistically significant six months before corresponding changes were seen in the EDSS score. EDSST6 as predicted by EDSST6= −1.027+0.037* age+0.217* s-EP-QT0 + 0.695* EDSST0 correlated with the observed values (rs=0.92, p<0.0001). Conclusions: Multimodal EPs correlate well with disability in PPMS, and allow some prediction of the disease course over three years. These findings support a role of EPs as surrogate markers in clinical trials in PPMS.

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.

Primary Progressive Multiple Sclerosis

Approximately 10% of patients with multiple sclerosis (MS) run a primary progressive course characterised by an accumulation of neurological deficits without relapse or remission. Designing therapeutic trials in primary progressive MS (PPMS) has presented several problems. Patient recruitment may be difficult because of the relative rarity of PPMS and historically has been hindered by the lack of specific diagnostic criteria. There has been a limited choice of validated outcome measures, although, in recent studies, the MS functional composite measure and magnetic resonance imaging measures of lesion load and atrophy have been widely used. Despite these problems, several trials have been designed specifically for PPMS, including exploratory randomised controlled trials of interferon-beta-1a and interferon-beta-1b and mitoxantrone, a phase III trial of glatiramer acetate, and an open-label study of riluzole. Patients with PPMS have also been included in randomised controlled trials of azathioprine, methotrexate, cladribine, intravenous immunoglobulin and cyclophosphamide, and open-label studies of haematopoietic stem cell transplantation and pirfenidone in progressive MS. However, no treatment has been proven definitively to modify the course of the disease. Looking to the future, therapeutic agents should aim to target the underlying pathogenic mechanisms in PPMS. As a result of the relative lack of inflammation in PPMS, neuroprotective agents that target neuronal loss directly, rather than inflammation, may be more worthwhile. However, further investigation into the pathogenic mechanisms in PPMS is required to guide the development of future therapeutic agents.

Natural history of primary progressive multiple sclerosis.

The relationship of primary progressive multiple sclerosis (PPMS) to relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS) remains unclear. Natural history data from a population-based cohort of patients with PPMS followed for approximately 25 years demonstrate remarkable similarities in the progressive phases of PPMS and SPMS. Immunogenetic and magnetic resonance imaging studies in large numbers of patients also fail to differentiate between the two MS categories. PPMS thus resembles SPMS without the relapses, although the two forms do differ with respect to sex ratio. An unfavourable outcome in PPMS in predicted by rapid early progression of disability and involvement of three or more systems. Natural history studies provide information on likely long-term outcomes and can be used in the design and interpretation of clinical trials in PPMS. The evidence that PPMS is distinct remains weak.