[Show abstract][Hide abstract] ABSTRACT: Biomarkers have become the focus of intense research in the field of amyotrophic lateral sclerosis (ALS), with the hope that they might aid therapy development efforts. Notwithstanding the discovery of many candidate biomarkers, none have yet emerged as validated tools for drug development. In this review we present a nuanced view of biomarkers based on the perspective of the FDA; highlight the distinction between discovery and validation; describe existing and emerging resources; review leading biological fluid-based, electrophysiological and neuroimaging candidates relevant to therapy development efforts; discuss lessons learned from biomarker initiatives in related neurodegenerative diseases; and outline specific steps that we, as a field, might take in order to hasten the development and validation of biomarkers that will prove useful in enhancing efforts to develop effective treatments for ALS patients. Most important among these perhaps is the proposal to establish a federated ALS Biomarker Consortium (ABC) in which all interested and willing stakeholders may participate with equal opportunity to contribute to the broader mission of biomarker development and validation. This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Multidisciplinary care in ALS is associated with longer survival, improved quality of life, and reduced hospital admissions, but there are no published data on institutional costs associated with multidisciplinary ALS care at U.S. centers. We prospectively examined institutional costs, adherence to AAN Practice Parameters and patient satisfaction in multidisciplinary ALS clinics at 18 U.S. ALS centers. Centers reported patient volumes; direct costs for staff salary/benefits, supplies and equipment; and institutional non-salary and overhead costs over a three-month period. In 1117 patients seen during this period, mean age was 61.5 years (range 25-91 years), 56% were male, and mean ALSFRS-R score was 29. Mean total salary/benefit cost per clinic day for all providers was $2964 (range $1692-$5236 across centers). Mean salary/benefit cost per patient per clinic was $507 (range $258-$806 across centers). Differences among centers in reporting non-salary costs prevented meaningful analysis. Practice parameter adherence and patient satisfaction were high. This prospective collaborative study demonstrates the direct financial burden of evidence-based multidisciplinary ALS care in the U.S.; more refined non-salary and overhead cost data are needed to evaluate the full cost impact of care. These data may be useful in supporting evidence-based models of patient centered care for ALS.
[Show abstract][Hide abstract] ABSTRACT: To assess the safety, tolerability, and preliminary efficacy of NP001, a novel immune regulator of inflammatory monocytes/macrophages, for slowing progression of amyotrophic lateral sclerosis (ALS).
This was a phase 2 randomized, double-blind, placebo-controlled trial of NP001 in 136 patients with ALS of <3 years' duration and forced vital capacity ≥70%. Participants received NP001 2 mg/kg, NP001 1 mg/kg, or placebo for 6 months. Safety, tolerability, and inflammatory biomarkers were assessed throughout the study. Preliminary efficacy was evaluated using the ALS Functional Rating Scale-Revised (ALSFRS-R) slope and change from baseline, with and without matched historical placebo controls, after 6 months of treatment. A post hoc analysis of the percentage of patients ("responders") whose ALSFRS-R did not change from baseline was also conducted.
NP001 was generally safe and well-tolerated, except for infusion site pain and dizziness. No significant slowing of decline in the primary or secondary measures was observed. However, slowing of progression was observed in the high-dose group in patients with greater inflammation (wide range C-reactive protein). Moreover, NP001 may have dose dependently halted symptom progression in a subset of patients. More than 2 times as many patients on high-dose NP001 (25%) did not progress during 6 months of treatment compared with those on placebo (11%). Most "responders" had an elevated biomarker of inflammation, interleukin-18, and were positive for lipopolysaccharide at baseline, which decreased after treatment with NP001.
The arresting of progression of ALS symptoms by NP001 in a subset of patients with marked neuroinflammation, as observed here, will represent a novel therapeutic approach for patients with ALS, if confirmed.
This study provides Class I evidence that for patients with ALS, NP001 is safe and did not significantly slow progression of the disease (difference in slope of the ALSFRS-R/month 0.12 favoring NP001, p = 0.55). The study lacks the precision to exclude an important effect of NP001.
[Show abstract][Hide abstract] ABSTRACT: The discovery of an expanded non-coding GGGGCC repeat expansion in the c9orf72 gene as the most common genetic cause of ALS and FTD (c9ALS/FTD) spurred the recent development of novel cellular and animal models recapitulating key disease features. However, the majority of models currently available have limitations. For example, overexpressing the expansion produces two disease hallmarks, RNA foci formation and repeat-associated non-ATG (RAN) translation, but not reduced expression of c9ORF72 mRNA and protein as seen in c9ALS/FTD patients. Potentially important events resulting from the expansion of the repeat within genomic DNA may be not present in the overexpression models. Moreover, it is technically difficult to clone a repeat sequence that would be similar in length to those observed in patients. To overcome such challenges, we present a method to transdifferentiate patients` dermal fibroblasts using a previously published vector encoding short hairpin RNA targeting polypyrimidine-tract-binding protein 1 (PTB1). PTB1 has been shown to inhibit neuronal differentiation triggered by miR-124 resulting in a cascade involving proneuronal alternative splicing events. We developed a protocol for a 2-week direct conversion of dermal fibroblasts to functional, induced neurons (iNeurons). The iNeurons generated from c9ALS/FTD patients formed more intranuclear RNA foci than fibroblasts and expressed RANT products (not detected in the parental fibroblasts). Moreover, we tested antisense short oligonucleotides (ASOs) targeting the pathogenic GGGGCC expansion in these cells and observed significant reductions in RNA foci, RANT product accumulation and cell toxicity. Taken together, our studies suggest iNeurons provide a fast and efficient tool for screening therapies.
[Show abstract][Hide abstract] ABSTRACT: Individuals carrying (GGGGCC) expanded repeats in the C9orf72 gene represent a significant portion of patients suffering from amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Elucidating how these expanded repeats cause "c9FTD/ALS" has since become an important goal of the field. Toward this end, we sought to investigate whether epigenetic changes are responsible for the decrease in C9orf72 expression levels observed in c9FTD/ALS patients. We obtained brain tissue from ten c9FTD/ALS individuals, nine FTD/ALS cases without a C9orf72 repeat expansion, and nine disease control participants, and generated fibroblastoid cell lines from seven C9orf72 expanded repeat carriers and seven participants carrying normal alleles. Chromatin immunoprecipitation using antibodies for histone H3 and H4 trimethylated at lysines 9 (H3K9), 27 (H3K27), 79 (H3K79), and 20 (H4K20) revealed that these trimethylated residues bind strongly to C9orf72 expanded repeats in brain tissue, but not to non-pathogenic repeats. Our finding that C9orf72 mRNA levels are reduced in the frontal cortices and cerebella of c9FTD/ALS patients is consistent with trimethylation of these histone residues, an event known to repress gene expression. Moreover, treating repeat carrier-derived fibroblasts with 5-aza-2-deoxycytidine, a DNA and histone demethylating agent, not only decreased C9orf72 binding to trimethylated histone residues, but also increased C9orf72 mRNA expression. Our results provide compelling evidence that trimethylation of lysine residues within histones H3 and H4 is a novel mechanism involved in reducing C9orf72 mRNA expression in expanded repeat carriers. Of importance, we show that mutant C9orf72 binding to trimethylated H3K9 and H3K27 is detectable in blood of c9FTD/ALS patients. Confirming these exciting results using blood from a larger cohort of patients may establish this novel epigenetic event as a biomarker for c9FTD/ALS.
Full-text · Article · Oct 2013 · Acta Neuropathologica