Understanding the patient and supporter journey in cocaine use disorder.

Background: There is a paucity of literature describing experiences and journey of individuals with cocaine use disorder (CUD) and supporters who care for them. The aim of this study was to understand and document the journey of individuals with current CUD, those in CUD remission, and supporters. Methods: The online bulletin board (OBB) is a qualitative tool where participants engage in an interactive discussion on a virtual forum. After completing a 15-minute screening questionnaire determining eligibility, individuals in CUD remission and supporters participated in an OBB for 60 minutes, split across 8 days over 2 weeks. Individuals with current CUD participated in a one-time virtual focus group discussion for 90 minutes. Results: Individuals in CUD remission (n=35) were from Brazil, France, Spain, the UK, and the US; those with current CUD (n=5) and supporters (n=6) were from the US. Key insights were that individuals with current CUD were seeking a 'euphoric high' that cocaine provides. Those in CUD remission described a 'euphoric high' when they first tried cocaine, but over time it became harder to re-create this feeling. Individuals in CUD remission expressed a 'rollercoaster' of emotions from when they first started using cocaine to when they stopped. Supporters were sad, isolated, and worried about a potential cocaine overdose for their loved ones with CUD. Conclusion: The study provides valuable insights into the experiences and journey of individuals with CUD and their supporters. Data generated from this study gives insights into this under-served and growing population.

Patient perspectives on current and potential therapies and clinical trial approaches for cocaine use disorder.

Background: Cocaine use disorder (CUD) is characterized by the continued use of cocaine despite serious impacts on life. This study focused on understanding the perspective of individuals with current CUD, individuals in CUD remission, and their supporters regarding current therapies, future therapies, and views on clinical trials for CUD. Methods: The online bulletin board (OBB) is a qualitative tool where participants engage in an interactive discussion on a virtual forum. Following completion of a screening questionnaire to determine eligibility, individuals in CUD remission and their supporters logged in to the OBB and responded to questions posed by the moderator. Individuals with current CUD participated in a one-time virtual focus group. Results: All individuals with current CUD and 94% of those in CUD remission reported a diagnosis consistent with CUD or substance use disorder during screening. Individuals with current CUD and their supporters were recruited from the United States (US). Individuals in CUD remission were recruited from five countries, including the US. Individuals with current CUD reported hesitation about seeking treatment due to stigma, a lack of privacy, and being labeled as a drug seeker; barriers to therapy included time, cost, and a lack of privacy. Participants wanted a safe therapy to stop cravings and withdrawal symptoms. Seven clinical trial outcomes, including long-term abstinence and craving control, were suggested based on collected insights. Conclusion: This study can help inform the design of clinical trials and emphasize the need for effective, safe, and accessible therapies. Recruiting participants will require significant trust building.

MIJ821 (onfasprodil) in healthy volunteers: First-in-human, randomized, placebo-controlled study (single ascending dose and repeated intravenous dose).

This single-center study administered MIJ821 (onfasprodil) as an intravenous infusion to healthy volunteers and included two parts: a single ascending dose study (Part 1) and a repeated intravenous dose study (Part 2). Primary objective was to evaluate the safety and tolerability of single ascending intravenous doses infused over a 40-min period and of two repeated doses (1 week apart) of MIJ821 in healthy volunteers. Secondary objectives were to assess the pharmacokinetics of MIJ821 after intravenous infusion in Part 1 and Part 2 of the study. Overall, 43 subjects in Part 1 and 12 subjects in Part 2 were randomized in the study. Median age in Part 1 and Part 2 was 45.0 and 43.5 years, respectively, with the majority being Caucasian (Part 1: 84%; Part 2: 92%). 19 subjects (44.2%) in Part 1 and 8 subjects (66.7%) in Part 2 experienced at least one adverse event (AE). Following single dose in Part 1 and Part 2, the AUCinf values of MIJ821 increased in a dose-proportional manner across the dose range 0.016-0.48 mg/kg and the Cmax values in a slight overproportional manner across the dose range 0.048-0.48 mg/kg. At the highest dose of 0.48 mg/kg, the geometric mean AUCinf was 708 h ng/mL and the geometric mean Cmax was 462 ng/mL. Inspection of 1-h post-dose resting electroencephalography activity across cohorts showed a relationship to administered dose, providing exploratory evidence of distal target engagement. In conclusion, MIJ821 showed a good safety and tolerability profile in healthy volunteers. Dissociative AEs were mild, transient, and dose-dependent.

Heterogeneity in Fragile X Syndrome Highlights the Need for Precision Medicine-Based Treatments.

Fragile X syndrome (FXS) is the most frequent monogenic cause of autism or intellectual disability, and research on its pathogenetic mechanisms has provided important insights on this neurodevelopmental condition. Nevertheless, after 30 years of intense research, efforts to develop treatments have been mostly unsuccessful. The aim of this review is to compile evidence from existing research pointing to clinical, genetic, and therapeutic response heterogeneity in FXS and highlight the need of implementing precision medicine-based treatments. We comment on the high genetic and phenotypic heterogeneity present in FXS, as a contributing factor to the difficulties found during drug development. Given that several clinical trials have showed a non-negligeable fraction of positive responders to drugs targeting core FXS symptoms, we propose that success of clinical trials can be achieved by tackling the underlying heterogeneity in FXS by accurately stratifying patients into drug-responder subpopulations. These precision medicine-based approaches, which can be first applied to well-defined monogenic diseases such as FXS, can also serve to define drug responder profiles based on specific biomarkers or phenotypic features that can associate patients with different genetic backgrounds to a same candidate drug, thus repositioning a same drug for a larger number of patients with NDDs.

A Study of Novel Exploratory Tools, Digital Technologies, and Central Nervous System Biomarkers to Characterize Unipolar Depression.

Background: Digital technologies have the potential to provide objective and precise tools to detect depression-related symptoms. Deployment of digital technologies in clinical research can enable collection of large volumes of clinically relevant data that may not be captured using conventional psychometric questionnaires and patient-reported outcomes. Rigorous methodology studies to develop novel digital endpoints in depression are warranted. Objective: We conducted an exploratory, cross-sectional study to evaluate several digital technologies in subjects with major depressive disorder (MDD) and persistent depressive disorder (PDD), and healthy controls. The study aimed at assessing utility and accuracy of the digital technologies as potential diagnostic tools for unipolar depression, as well as correlating digital biomarkers to clinically validated psychometric questionnaires in depression. Methods: A cross-sectional, non-interventional study of 20 participants with unipolar depression (MDD and PDD/dysthymia) and 20 healthy controls was conducted at the Centre for Human Drug Research (CHDR), the Netherlands. Eligible participants attended three in-clinic visits (days 1, 7, and 14), at which they underwent a series of assessments, including conventional clinical psychometric questionnaires and digital technologies. Between the visits, there was at-home collection of data through mobile applications. In all, seven digital technologies were evaluated in this study. Three technologies were administered via mobile applications: an interactive tool for the self-assessment of mood, and a cognitive test; a passive behavioral monitor to assess social interactions and global mobility; and a platform to perform voice recordings and obtain vocal biomarkers. Four technologies were evaluated in the clinic: a neuropsychological test battery; an eye motor tracking system; a standard high-density electroencephalogram (EEG)-based technology to analyze the brain network activity during cognitive testing; and a task quantifying bias in emotion perception. Results: Our data analysis was organized by technology - to better understand individual features of various technologies. In many cases, we obtained simple, parsimonious models that have reasonably high diagnostic accuracy and potential to predict standard clinical outcome in depression. Conclusion: This study generated many useful insights for future methodology studies of digital technologies and proof-of-concept clinical trials in depression and possibly other indications.

Regional brain mGlu5 receptor occupancy following single oral doses of mavoglurant as measured by [11C]-ABP688 PET imaging in healthy volunteers.

Mavoglurant binds to same allosteric site on metabotropic glutamate receptor 5 (mGluR5) as [11C]-ABP688, a radioligand. This open-label, single-center pilot study estimates extent of occupancy of mGluR5 receptors following single oral doses of mavoglurant, using [11C]-ABP688 positron emission tomography (PET) imaging, in six healthy males aged 20-40 years. This study comprised three periods and six subjects were divided into two cohorts. On Day 1 (Period 1), baseline clinical data and safety samples were obtained along with PET scan. During Period 2 (1-7 days after Period 1), cohort 1 and 2 received mavoglurant 25 mg and 100 mg, respectively. During Period 3 (7 days after Period 2), cohort 1 and 2 received mavoglurant 200 mg and 400 mg, respectively. Mavoglurant showed the highest distribution volumes in the cingulate region with lower uptake in cerebellum and white matter, possibly because myelinated axonal sheets maybe devoid of mGlu5 receptors. Maximum concentrations of mavoglurant were observed around 2-3.25 h post-dose. Mavoglurant passed the blood-brain barrier and induced dose- and exposure-dependent displacement of [11C]-ABP688 from the mGluR5 receptors, 3-4 h post-administration (27%, 59%, 74%, 85% receptor occupancy for mavoglurant 25 mg, 100 mg, 200 mg, 400 mg dose, respectively). There were no severe adverse effects or clinically significant changes in safety parameters. This is the first human receptor occupancy study completed with Mavoglurant. It served to guide the dosing of mavoglurant in the past and currently ongoing clinical studies. Furthermore, it confirms the utility of [11C]-ABP688 as a unique tool to study drug-induced occupancy of mGlu5 receptors in the living human brain.

Rivastigmine in Parkinson's Disease Dementia with Orthostatic Hypotension.

OBJECTIVE: The purpose of this study was to evaluate if the cognitive benefit of rivastigmine is affected by the presence of orthostatic hypotension (OH) in patients with Parkinson's disease dementia (PDD). METHODS: We conducted a post hoc analysis on 1,047 patients with PDD from 2 randomized controlled trials comparing rivastigmine versus placebo at week 24 (n = 501) and rivastigmine patch versus capsule at week 76 (n = 546). A drop ≥ 20 mm Hg in systolic blood pressure (SBP) or ≥ 10 in diastolic blood pressure (DBP) upon standing classified subjects as OH positive (OH+); otherwise, OH negative (OH-). The primary end point was the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog) at week 24 and the Mattis Dementia Rating Scale (MDRS) at week 76, using intention-to-treat with retrieved dropout at week 24 and observed cases at week 76, consistent with the original analyses. RESULTS: Overall safety was comparable between OH+ (n = 288, 27.5%) and OH- (n = 730, 69.7%), except for higher frequency of syncope (9.2%) in the OH+ placebo arm. The placebo-adjusted effect of rivastigmine on ADAS-Cog at week 24 was 5.6 ± 1.2 for OH+ and 1.9 ± 0.9 in OH- (p = 0.0165). Among subjects with OH, the MDRS change from baseline at week 76 was higher for rivastigmine capsules versus patch (10.6 ± 2.9 vs -1.5 ± 3.0, p = 0.031). The overall prevalence of OH was lower for rivastigmine than placebo at week 24 (28.3% vs 44.6%, p = 0.0476). INTERPRETATION: The cognitive benefit from rivastigmine is larger in patients with PDD with OH, possibly mediated by a direct antihypotensive effect. ANN NEUROL 2021;89:91-98.

First-in-Man Intrathecal Application of Neurite Growth-Promoting Anti-Nogo-A Antibodies in Acute Spinal Cord Injury.

BACKGROUND: Neutralization of central nervous system neurite growth inhibitory factors, for example, Nogo-A, is a promising approach to improving recovery following spinal cord injury (SCI). In animal SCI models, intrathecal delivery of anti-Nogo-A antibodies promoted regenerative neurite growth and functional recovery. OBJECTIVE: This first-in-man study assessed the feasibility, safety, tolerability, pharmacokinetics, and preliminary efficacy of the human anti-Nogo-A antibody ATI355 following intrathecal administration in patients with acute, complete traumatic paraplegia and tetraplegia. METHODS: Patients (N = 52) started treatment 4 to 60 days postinjury. Four consecutive dose-escalation cohorts received 5 to 30 mg/2.5 mL/day continuous intrathecal ATI355 infusion over 24 hours to 28 days. Following pharmacokinetic evaluation, 2 further cohorts received a bolus regimen (6 intrathecal injections of 22.5 and 45 mg/3 mL, respectively, over 4 weeks). RESULTS: ATI355 was well tolerated up to 1-year follow-up. All patients experienced ≥1 adverse events (AEs). The 581 reported AEs were mostly mild and to be expected following acute SCI. Fifteen patients reported 16 serious AEs, none related to ATI355; one bacterial meningitis case was considered related to intrathecal administration. ATI355 serum levels showed dose-dependency, and intersubject cerebrospinal fluid levels were highly variable after infusion and bolus injection. In 1 paraplegic patient, motor scores improved by 8 points. In tetraplegic patients, mean total motor scores increased, with 3/19 gaining >10 points, and 1/19 27 points at Week 48. Conversion from complete to incomplete SCI occurred in 7/19 patients with tetraplegia. CONCLUSIONS: ATI335 was well tolerated in humans; efficacy trials using intrathecal antibody administration may be considered in acute SCI.

Protein synthesis levels are increased in a subset of individuals with fragile X syndrome.

Fragile X syndrome (FXS) is a monogenic form of intellectual disability and autism spectrum disorder caused by the absence of the fragile X mental retardation protein (FMRP). In biological models for the disease, this leads to upregulated mRNA translation and as a consequence, deficits in synaptic architecture and plasticity. Preclinical studies revealed that pharmacological interventions restore those deficits, which are thought to mediate the FXS cognitive and behavioral symptoms. Here, we characterized the de novo rate of protein synthesis in patients with FXS and their relationship with clinical severity. We measured the rate of protein synthesis in fibroblasts derived from 32 individuals with FXS and from 17 controls as well as in fibroblasts and primary neurons of 27 Fmr1 KO mice and 20 controls. Here, we show that levels of protein synthesis are increased in fibroblasts of individuals with FXS and Fmr1 KO mice. However, this cellular phenotype displays a broad distribution and a proportion of fragile X individuals and Fmr1 KO mice do not show increased levels of protein synthesis, having measures in the normal range. Because the same Fmr1 KO animal measures in fibroblasts predict those in neurons we suggest the validity of this peripheral biomarker. Our study offers a potential explanation for the comprehensive drug development program undertaken thus far yielding negative results and suggests that a significant proportion, but not all individuals with FXS, may benefit from the reduction of excessive levels of protein synthesis.

Drug development for neurodevelopmental disorders: lessons learned from fragile X syndrome.

Neurodevelopmental disorders such as fragile X syndrome (FXS) result in lifelong cognitive and behavioural deficits and represent a major public health burden. FXS is the most frequent monogenic form of intellectual disability and autism, and the underlying pathophysiology linked to its causal gene, FMR1, has been the focus of intense research. Key alterations in synaptic function thought to underlie this neurodevelopmental disorder have been characterized and rescued in animal models of FXS using genetic and pharmacological approaches. These robust preclinical findings have led to the implementation of the most comprehensive drug development programme undertaken thus far for a genetically defined neurodevelopmental disorder, including phase IIb trials of metabotropic glutamate receptor 5 (mGluR5) antagonists and a phase III trial of a GABAB receptor agonist. However, none of the trials has been able to unambiguously demonstrate efficacy, and they have also highlighted the extent of the knowledge gaps in drug development for FXS and other neurodevelopmental disorders. In this Review, we examine potential issues in the previous studies and future directions for preclinical and clinical trials. FXS is at the forefront of efforts to develop drugs for neurodevelopmental disorders, and lessons learned in the process will also be important for such disorders.

Deficient striatal adaptation in aminergic and glutamatergic neurotransmission is associated with tardive dyskinesia in non-human primates exposed to antipsychotic drugs.

Tardive dyskinesia (TD) is a potentially disabling condition encompassing all delayed, persistent, and often irreversible abnormal involuntary movements arising in a fraction of subjects during long-term exposure to centrally acting dopamine receptor-blocking agents such as antipsychotic drugs and metoclopramide. However, the pathogenesis of TD has proved complex and remains elusive. To investigate the mechanism underlying the development of TD, we have chronically exposed 17 Cebus apella monkeys to typical (11) or atypical (6) antipsychotic drugs. Six additional monkeys were used as controls. Using autoradiography, Western blot and in situ hybridization techniques, we compared neurochemical components of the dopamine, serotonin, and glutamate neurotransmitter systems modulating striatal activity in monkeys chronically exposed to haloperidol and clozapine. Five (5) out of 11 monkeys treated with haloperidol develop TD, whereas none of the monkeys treated with clozapine develop TD. Haloperidol treatment significantly upregulated the levels of serotonin 5-HT2A receptor, NR2A-containing NMDA receptors, and tyrosine hydroxylase contents in the monkey putamen, whereas clozapine regulated putamen NMDA receptor levels and tyrosine hydroxylase contents, and 5-HT2A and dopamine transporter outside the putamen. Comparisons of neurochemical alterations between dyskinetic and non dyskinetic animals within the haloperidol-treated group indicate that modulations of 5-HT2A, metabotropic glutamate type 5, NR2A- and NR2B-containing NMDA receptors, and vesicular monoamine transporter type 2 levels were restricted to the non dyskinetic group. The foregoing results suggest that TD is associated with complex deficient adaptation in aminergic and glutamatergic neurotransmission in the striatum of non-human primates chronically exposed to antipsychotic drugs.

Mavoglurant Augmentation in OCD Patients Resistant to Selective Serotonin Reuptake Inhibitors: A Proof-of-Concept, Randomized, Placebo-Controlled, Phase 2 Study.

INTRODUCTION: To determine if mavoglurant (modified release) as an augmentation therapy to selective serotonin reuptake inhibitors (SSRIs) could have beneficial effects reducing Yale-Brown Obsessive Compulsive Scale (Y-BOCS) total score in patients with obsessive-compulsive disorder (OCD) resistant to SSRI treatment. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled, parallel-group, phase 2 study. Patients remained on their SSRI treatment and mavoglurant or placebo was added on. Non-smoking men and women aged 18-65 years primarily diagnosed with OCD according to Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR) criteria were randomized (1:1) to mavoglurant or placebo groups. After 50 patients were randomized, an interim analysis was conducted to determine whether the study should be continued. The primary outcome measure was absolute change in Y-BOCS from baseline at week 17. Safety was assessed by recording adverse events (AEs) and serious adverse events (SAEs). RESULTS: Interim analysis led to a decision to terminate the study. In total 38 (76.0%) participants completed 17 weeks of treatment and 37 (74.0%) completed the study. There was no significant difference in least squares (LS) mean change from baseline at week 17 in Y-BOCS total score for mavoglurant compared with placebo groups [-6.9 (1.75) vs. -8.0 (1.78), respectively; LS mean difference 1.1; 95% CI -3.9, 6.2; p = 0.671]. The incidence of AEs was higher in the mavoglurant compared with the placebo group (80.8% vs. 70.8%, respectively). CONCLUSION: This study of mavoglurant in OCD was terminated because of the lack of efficacy at interim analysis. The study did not support the use of an antagonist of mGluR5 receptors for OCD treatment. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov: NCT01813019. FUNDING: This study was sponsored by Novartis Pharma AG, Basel, Switzerland.

CGG Repeat-Induced FMR1 Silencing Depends on the Expansion Size in Human iPSCs and Neurons Carrying Unmethylated Full Mutations.

In fragile X syndrome (FXS), CGG repeat expansion greater than 200 triplets is believed to trigger FMR1 gene silencing and disease etiology. However, FXS siblings have been identified with more than 200 CGGs, termed unmethylated full mutation (UFM) carriers, without gene silencing and disease symptoms. Here, we show that hypomethylation of the FMR1 promoter is maintained in induced pluripotent stem cells (iPSCs) derived from two UFM individuals. However, a subset of iPSC clones with large CGG expansions carries silenced FMR1. Furthermore, we demonstrate de novo silencing upon expansion of the CGG repeat size. FMR1 does not undergo silencing during neuronal differentiation of UFM iPSCs, and expression of large unmethylated CGG repeats has phenotypic consequences resulting in neurodegenerative features. Our data suggest that UFM individuals do not lack the cell-intrinsic ability to silence FMR1 and that inter-individual variability in the CGG repeat size required for silencing exists in the FXS population.

Task-related fMRI responses to a nicotinic acetylcholine receptor partial agonist in schizophrenia: A randomized trial.

INTRODUCTION: AQW051, an α7-nicotinic acetylcholine receptor partial agonist, enhanced cognitive function in rodent models of learning and memory. This study evaluated brain activation during performance of a working memory task (WMT) and an episodic memory task (EMT), and the effect of AQW051 on task-related brain activation and performance in subjects with schizophrenia. METHODS: This was a double-blind, randomized, placebo-controlled, multicenter, 2-period cross-over trial (NCT00825539) in participants with chronic, stable schizophrenia. Participants, stratified according to smoking status, were randomized (1:1:1:1:1:1) to 1 of 6 sequence groups that determined the study drug dose (AQW051 7.5mg, 50mg or 100mg) and order of administration versus placebo. The primary outcome was brain activation in a priori target regions of interest (ROIs) during performance of the WMT and EMT, measured using functional magnetic resonance imaging. The effect of AQW051 on task-related (EMT and WMT) brain activation and performance was also assessed, as were safety and tolerability. RESULTS: Overall, 60 of 68 enrolled participants completed the study (AQW051 then placebo: 7.5mg n=9; 50mg n=11; 100mg n=10. Placebo then AQW051: 7.5mg n=10; 50mg n=11; 100mg n=9). Significant task-related brain activation (5% significance level) was observed with placebo. During the WMT, a medium effect size was observed in the inferior prefrontal cortex with AQW051 100mg versus placebo (0.431; p=0.105). During the EMT encoding phase, a large effect size was observed in the anterior hippocampus (0.795; p=0.007) and a medium effect size in the posterior hippocampus (0.476; p=0.079) with AQW051 7.5mg. No other medium/large effect sizes were observed with any dose on either task. Effects on brain activation were generally not associated with changes in cognitive performance. AQW051 was well tolerated with an acceptable safety profile. CONCLUSIONS: Overall, no consistent effects of AQW051 on brain regions involved in the performance of a WMT or EMT were observed; however, this study presents a model for evaluating potential response to pharmacological interventions for cognitive impairment in schizophrenia.

A Placebo-Controlled Trial of AQW051 in Patients With Moderate to Severe Levodopa-Induced Dyskinesia.

BACKGROUND: This phase 2 randomized, double-blind, placebo-controlled study evaluated the efficacy and safety of the nicotinic acetylcholine receptor α7 agonist AQW051 in patients with Parkinson's disease and levodopa-induced dyskinesia. METHODS: Patients with idiopathic Parkinson's disease and moderate to severe levodopa-induced dyskinesia were randomized to AQW051 10 mg (n = 24), AQW051 50 mg (n = 24), or placebo (n = 23) once daily for 28 days. Coprimary end points were change in Modified Abnormal Involuntary Movement Scale and Unified Parkinson's Disease Rating Scale part III scores. Secondary outcomes included pharmacokinetics. RESULTS: In total, 67 patients completed the study. AQW051-treated patients experienced no significant improvements in Modified Abnormal Involuntary Movement Scale or Unified Parkinson's Disease Rating Scale part III scores by day 28. AQW051 was well tolerated; the most common adverse events were dyskinesia, fatigue, nausea, and falls. CONCLUSIONS: AQW051 did not significantly reduce dyskinesia or parkinsonian severity. © 2016 International Parkinson and Movement Disorder Society.

Reciprocal changes in DNA methylation and hydroxymethylation and a broad repressive epigenetic switch characterize FMR1 transcriptional silencing in fragile X syndrome.

BACKGROUND: Fragile X syndrome (FXS) is the most common form of inherited intellectual disability, resulting from the loss of function of the fragile X mental retardation 1 (FMR1) gene. The molecular pathways associated with FMR1 epigenetic silencing are still elusive, and their characterization may enhance the discovery of novel therapeutic targets as well as the development of novel clinical biomarkers for disease status. RESULTS: We have deployed customized epigenomic profiling assays to comprehensively map the FMR1 locus chromatin landscape in peripheral mononuclear blood cells (PBMCs) from eight FXS patients and in fibroblast cell lines derived from three FXS patient. Deoxyribonucleic acid (DNA) methylation (5-methylcytosine (5mC)) and hydroxymethylation (5-hydroxymethylcytosine (5hmC)) profiling using methylated DNA immunoprecipitation (MeDIP) combined with a custom FMR1 microarray identifies novel regions of DNA (hydroxy)methylation changes within the FMR1 gene body as well as in proximal flanking regions. At the region surrounding the FMR1 transcriptional start sites, increased levels of 5mC were associated to reciprocal changes in 5hmC, representing a novel molecular feature of FXS disease. Locus-specific validation of FMR1 5mC and 5hmC changes highlighted inter-individual differences that may account for the expected DNA methylation mosaicism observed at the FMR1 locus in FXS patients. Chromatin immunoprecipitation (ChIP) profiling of FMR1 histone modifications, together with 5mC/5hmC and gene expression analyses, support a functional relationship between 5hmC levels and FMR1 transcriptional activation and reveal cell-type specific differences in FMR1 epigenetic regulation. Furthermore, whilst 5mC FMR1 levels positively correlated with FXS disease severity (clinical scores of aberrant behavior), our data reveal for the first time an inverse correlation between 5hmC FMR1 levels and FXS disease severity. CONCLUSIONS: We identify novel, cell-type specific, regions of FMR1 epigenetic changes in FXS patient cells, providing new insights into the molecular mechanisms of FXS. We propose that the combined measurement of 5mC and 5hmC at selected regions of the FMR1 locus may significantly enhance FXS clinical diagnostics and patient stratification.

Assessment of Cognitive Outcome Measures in Teenagers with 15q13.3 Microdeletion Syndrome.

15q13.3 microdeletion syndrome causes a spectrum of cognitive disorders, including intellectual disability and autism. We aimed to determine if any or all of three cognitive testing systems (the KiTAP, CogState, and Stanford-Binet) are suitable for assessment of cognitive function in affected individuals. These three tests were administered to ten individuals with 15q13.3 microdeletion syndrome (14-18 years of age), and the results were analyzed to determine feasibility of use, potential for improvement, and internal consistency. It was determined that the KiTAP, CogState, and Stanford-Binet are valid tests of cognitive function in 15q13.3 microdeletion patients. Therefore, these tests may be considered for use as objective outcome measures in future clinical trials, assessing change in cognitive function over a period of pharmacological treatment.

High-Throughput Screening Using iPSC-Derived Neuronal Progenitors to Identify Compounds Counteracting Epigenetic Gene Silencing in Fragile X Syndrome.

Fragile X syndrome (FXS) is the most common form of inherited mental retardation, and it is caused in most of cases by epigenetic silencing of the Fmr1 gene. Today, no specific therapy exists for FXS, and current treatments are only directed to improve behavioral symptoms. Neuronal progenitors derived from FXS patient induced pluripotent stem cells (iPSCs) represent a unique model to study the disease and develop assays for large-scale drug discovery screens since they conserve the Fmr1 gene silenced within the disease context. We have established a high-content imaging assay to run a large-scale phenotypic screen aimed to identify compounds that reactivate the silenced Fmr1 gene. A set of 50,000 compounds was tested, including modulators of several epigenetic targets. We describe an integrated drug discovery model comprising iPSC generation, culture scale-up, and quality control and screening with a very sensitive high-content imaging assay assisted by single-cell image analysis and multiparametric data analysis based on machine learning algorithms. The screening identified several compounds that induced a weak expression of fragile X mental retardation protein (FMRP) and thus sets the basis for further large-scale screens to find candidate drugs or targets tackling the underlying mechanism of FXS with potential for therapeutic intervention.

A randomized, placebo-controlled trial of AFQ056 for the treatment of chorea in Huntington's disease.

BACKGROUND: This study investigated the hypothesis that AFQ056 (mavoglurant), a selective metabotropic glutamate receptor 5 antagonist, reduces chorea in Huntington's disease (HD). METHODS: This 32-day randomized, double-blind, parallel-group, proof-of-concept study investigated AFQ056 (25-150 mg [incremental doses], twice-daily) versus placebo in patients with HD. Primary efficacy assessments were the chorea-sum score and orientation index (nondominant hand) from the quantitative motor (Q-Motor) grasping task at day 28. Key secondary efficacy assessments included finger-tapping in the Unified Huntington's Disease Rating Scale-Total Motor Score and Q-Motor measures. Safety and tolerability were assessed. RESULTS: Overall, 42 patients were randomized. At day 28, no improvement was observed on the primary efficacy assessments (P > 0.10) with AFQ056 versus placebo. The Q-Motor speeded-tapping interonset interval variability was reduced with AFQ056 versus placebo for the nondominant hand (P = 0.01). The incidence of adverse events was 66.7% with AFQ056 and 57.1% with placebo. CONCLUSIONS: AFQ056 did not reduce choreatic movements in HD, but was well tolerated. The clinical relevance of the Q-Motor findings (speeded-tapping) are unknown and may warrant further investigation.