Longitudinal biomarkers in amyotrophic lateral sclerosis

OBJECTIVE: To investigate neurodegenerative and inflammatory biomarkers in people with amyotrophic lateral sclerosis (PALS), evaluate their predictive value for ALS progression rates, and assess their utility as pharmacodynamic biomarkers for monitoring treatment effects. METHODS: De-identified, longitudinal plasma, and cerebrospinal fluid (CSF) samples from PALS (n = 108; 85 with samples from \u3e /=2 visits) and controls without neurological disease (n = 41) were obtained from the Northeast ALS Consortium (NEALS) Biofluid Repository. Seventeen of 108 PALS had familial ALS, of whom 10 had C9orf72 mutations. Additional healthy control CSF samples (n = 35) were obtained from multiple sources. We stratified PALS into fast- and slow-progression subgroups using the ALS Functional Rating Scale-Revised change rate. We compared cytokines/chemokines and neurofilament (NF) levels between PALS and controls, among progression subgroups, and in those with C9orf72 mutations. RESULTS: We found significant elevations of cytokines, including MCP-1, IL-18, and neurofilaments (NFs), indicators of neurodegeneration, in PALS versus controls. Among PALS, these cytokines and NFs were significantly higher in fast-progression and C9orf72 mutation subgroups versus slow progressors. Analyte levels were generally stable over time, a key feature for monitoring treatment effects. We demonstrated that CSF/plasma neurofilament light chain (NFL) levels may predict disease progression, and stratification by NFL levels can enrich for more homogeneous patient groups. INTERPRETATION: Longitudinal stability of cytokines and NFs in PALS support their use for monitoring responses to immunomodulatory and neuroprotective treatments. NFs also have prognostic value for fast-progression patients and may be used to select similar patient subsets in clinical trials

Suppression of MAPK11 or HIPK3 reduces mutant Huntingtin levels in Huntington's disease models.

Most neurodegenerative disorders are associated with accumulation of disease-relevant proteins. Among them, Huntington disease (HD) is of particular interest because of its monogenetic nature. HD is mainly caused by cytotoxicity of the defective protein encoded by the mutant Huntingtin gene (HTT). Thus, lowering mutant HTT protein (mHTT) levels would be a promising treatment strategy for HD. Here we report two kinases HIPK3 and MAPK11 as positive modulators of mHTT levels both in cells and in vivo. Both kinases regulate mHTT via their kinase activities, suggesting that inhibiting these kinases may have therapeutic values. Interestingly, their effects on HTT levels are mHTT-dependent, providing a feedback mechanism in which mHTT enhances its own level thus contributing to mHTT accumulation and disease progression. Importantly, knockout of MAPK11 significantly rescues disease-relevant behavioral phenotypes in a knockin HD mouse model. Collectively, our data reveal new therapeutic entry points for HD and target-discovery approaches for similar diseases

Biofluid Biomarkers in Huntington's Disease

Huntington's disease (HD) is a chronic progressive neurodegenerative condition where new markers of disease progression are needed. So far no disease-modifying interventions have been found, and few interventions have been proven to alleviate symptoms. This may be partially explained by the lack of reliable indicators of disease severity, progression, and phenotype.Biofluid biomarkers may bring advantages in addition to clinical measures, such as reliability, reproducibility, price, accuracy, and direct quantification of pathobiological processes at the molecular level; and in addition to empowering clinical trials, they have the potential to generate useful hypotheses for new drug development.In this chapter we review biofluid biomarker reports in HD, emphasizing those we feel are likely to be closest to clinical applicability

Safety, tolerability, and efficacy of PBT2 in Huntington's disease: A phase 2, randomised, double-blind, placebo-controlled trial

Background: PBT2 is a metal protein-attenuating compound that might reduce metal-induced aggregation of mutant huntingtin and has prolonged survival in a mouse model of Huntington's disease. We aimed to assess the safety, tolerability, and efficacy of PBT2 in patients with Huntington's disease. Methods: In this 26-week, randomised, double-blind, placebo-controlled trial, adults ( ≥ 25 years old ) with early-stage to mid-stage Huntington's disease were randomly assigned ( 1:1:1 ) by a centralised interactive response system to once daily PBT2 250 mg, PBT2 100 mg, or placebo. Randomisation was stratified by site with a block size of three. Participants, carers, the steering committee, site investigators, study staff, and the study sponsor were masked to treatment assignment. Primary endpoints were safety and tolerability. The safety population consisted of all participants who were randomly assigned and had at least one dose of study drug. The principal secondary endpoint was cognition, measured by the change from baseline to week 26 in the main composite Z score of five cognitive tests ( Category Fluency Test, Trail Making Test Part B, Map Search, Symbol Digit Modalities Test, and Stroop Word Reading Test ) and scores on eight individual cognitive tests ( the five aforementioned plus the Trail Making Test Part A, Montreal Cognitive Assessment, and the Speeded Tapping Test ). The intention-to-treat population comprised participants who were randomly assigned and had at least one efficacy assessment after administration of study drug. This trial is registered with [http://clinicaltrials.gov/] ClinicalTrials.gov, [http://clinicaltrials.gov/show/NCT01590888] NCT01590888. Findings: Between April 18, 2012, and Dec 14, 2012, 109 participants were randomly assigned to PBT2 250 mg ( n=36 ), PBT2 100 mg ( n=38 ), or placebo ( n=35 ) at 19 research centres in Australia and the USA. 32 ( 89% ) individuals on PBT2 250 mg, 38 ( 100% ) on PBT2 100 mg, and 34 ( 97% ) on placebo completed the study. Six serious adverse events ( acute coronary syndrome, major depression, pneumonia, suicide attempt, viral infection, and worsening of Huntington's disease ) occurred in five participants in the PBT2 250 mg group, three ( fall with subdural haematoma, suicide attempt, and hospital admission for stabilisation of Huntington's disease ) occurred in two participants in the PBT2 100 mg group, and one ( increasing aggression ) occurred in a participant in the placebo group. The site investigators deemed all, except the worsening of Huntington's disease, as unrelated to study drug. 32 ( 89% ) participants on PBT2 250 mg, 30 ( 79% ) on PBT2 100 mg, and 28 ( 80% ) on placebo had at least one adverse event. Compared with placebo, neither PBT2 100 mg ( least-squares mean 0·02, 95% CI −0·10 to 0·14; p=0·772 ) nor PBT2 250 mg ( 0·07, −0·05 to 0·20; p=0·240 ) significantly improved the main composite cognition Zscore between baseline and 26 weeks. Compared with placebo, the Trail Making Test Part B score was improved between baseline and 26 weeks in the PBT2 250 mg group ( 17·65 s, 0·65–34·65; p=0·042 ) but not in the 100 mg group ( 0·79 s improvement, −15·75 to 17·32; p=0·925 ); neither dose significantly improved cognition on the other tests. Interpretation: PBT2 was generally safe and well tolerated in patients with Huntington's disease. The potential benefit on executive function will need to be confirmed in a larger study. Funding: Prana Biotechnology Limited

Huntington disease: natural history, biomarkers and prospects for therapeutics

Huntington disease (HD) can be seen as a model neurodegenerative disorder, in that it is caused by a single genetic mutation and is amenable to predictive genetic testing, with estimation of years to predicted onset, enabling the entire range of disease natural history to be studied. Structural neuroimaging biomarkers show that progressive regional brain atrophy begins many years before the emergence of diagnosable signs and symptoms of HD, and continues steadily during the symptomatic or 'manifest' period. The continued development of functional, neurochemical and other biomarkers raises hopes that these biomarkers might be useful for future trials of disease-modifying therapeutics to delay the onset and slow the progression of HD. Such advances could herald a new era of personalized preventive therapeutics. We describe the natural history of HD, including the timing of emergence of motor, cognitive and emotional impairments, and the techniques that are used to assess these features. Building on this information, we review recent progress in the development of biomarkers for HD, and potential future roles of these biomarkers in clinical trials