A Randomized, Double-blind, Placebo-Controlled Study of Latrepirdine in Patients With Mild to Moderate Huntington Disease.

BACKGROUND Latrepirdine is an orally administered experimental small molecule that was initially developed as an antihistamine and subsequently was shown to stabilize mitochondrial membranes and function, which might be impaired in Huntington disease. OBJECTIVE To determine the effect of latrepirdine on cognition and global function in patients with mild to moderate Huntington disease. DESIGN Randomized, double-blind, placebo-controlled study. SETTING Sixty-four research centers in Australia, Europe, and North America. PATIENTS Four hundred three patients with mild to moderate Huntington disease and baseline cognitive impairment (Mini-Mental State Examination score, 10-26). INTERVENTION Latrepirdine (20 mg) vs matching placebo administered orally 3 times daily for 26 weeks. MAIN OUTCOME MEASURES The co-primary outcome measures were cognition as measured by the change in Mini-Mental State Examination score from baseline to week 26 and global function at week 26 as measured by the Clinician Interview-Based Impression of Change, plus carer interview, which ranges from 1 (marked improvement) to 7 (marked worsening). Secondary efficacy outcome measures included behavior, daily function, motor function, and safety. RESULTS The mean change in Mini-Mental State Examination score among participants randomized to latrepirdine (1.5-point improvement) did not differ significantly from that among participants randomized to placebo (1.3-point improvement) (P = .39). Similarly, the distribution of the Clinician Interview-Based Impression of Change, plus carer interview did not differ significantly among those randomized to latrepirdine compared with placebo (P = .84). No significant treatment effects were detected on the secondary efficacy outcome measures. The incidence of adverse events was similar between those randomized to latrepirdine (68.5%) and placebo (68.0%). CONCLUSION In patients with mild to moderate Huntington disease and cognitive impairment, treatment with latrepirdine for 6 months was safe and well tolerated but did not improve cognition or global function relative to placebo. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00920946

Perinatal insults and neurodevelopmental disorders may impact Huntington's disease age of diagnosis

Introduction: The age of diagnosis of Huntington's disease (HD) varies among individuals with the same HTT CAG-repeat expansion size. We investigated whether early-life events, like perinatal insults or neurodevelopmental disorders, influence the diagnosis age. Methods: We used data from 13,856 participants from REGISTRY and Enroll-HD, two large international multicenter observational studies. Disease-free survival analyses of mutation carriers with an HTT CAG repeat expansion size above and including 36 were computed through Kaplan-Meier estimates of median time until an HD diagnosis. Comparisons between groups were computed using a Cox proportional hazard survival model adjusted for CAG-repeat expansion length. We also assessed whether the group effect depended on gender and the affected parent. Results: Insults in the perinatal period were associated with an earlier median age of diagnosis of 45.00 years (95%CI: 42.07–47.92) compared to 51.00 years (95%CI: 50.68–51.31) in the reference group, with a CAG-adjusted hazard ratio of 1.61 (95%CI: 1.26–2.06). Neurodevelopmental disorders were also associated with an earlier median age of diagnosis than the reference group of 47.00 years (95% CI: 43.38–50.62) with a CAG-adjusted hazard ratio of 1.42 (95%CI: 1.16–1.75). These associations did not change significantly with gender or affected parent. Conclusions: These results, derived from large observational datasets, show that perinatal insults and neurodevelopmental disorders are associated with earlier ages of diagnosis of magnitudes similar to the effects of known genetic modifiers of HD. Given their clear temporal separation, these early events may be causative of earlier HD onset, but further research is needed to prove causation

Exploring genetic factors involved in huntington disease age of onset. E2F2 as a new potential modifier gene

Age of onset (AO) of Huntington disease (HD) is mainly determined by the length of the CAG repeat expansion (CAGexp) in exon 1 of the HTT gene. Additional genetic variation has been suggested to contribute to AO, although the mechanism by which it could affect AO is presently unknown. The aim of this study is to explore the contribution of candidate genetic factors to HD AO in order to gain insight into the pathogenic mechanisms underlying this disorder. For that purpose, two AO definitions were used: the earliest age with unequivocal signs of HD (earliest AO or eAO), and the first motor symptoms age (motor AO or mAO). Multiple linear regression analyses were performed between genetic variation within 20 candidate genes and eAO or mAO, using DNA and clinical information of 253 HD patients from REGISTRY project. Gene expression analyses were carried out by RT-qPCR with an independent sample of 35 HD patients from Basque Country Hospitals. We found suggestive association signals between HD eAO and/or mAO and genetic variation within the E2F2, ATF7IP, GRIN2A, GRIN2B, LINC01559, HIP1 and GRIK2 genes. Among them, the most significant was the association between eAO and rs2742976, mapping to the promoter region of E2F2 transcription factor. Furthermore, rs2742976 T allele patient carriers exhibited significantly lower lymphocyte E2F2 gene expression, suggesting a possible implication of E2F2-dependent transcriptional activity in HD pathogenesis. Thus, E2F2 emerges as a new potential HD AO modifier factor

Discovery of Therapeutic Approaches for Polyglutamine Diseases: A Summary of Recent Efforts

Polyglutamine (PolyQ) diseases are a group of neurodegenerative disorders caused by the expansion of cytosine-adenine-guanine (CAG) trinucleotide repeats in the coding region of specific genes. This leads to the production of pathogenic proteins containing critically expanded tracts of glutamines. Although polyQ diseases are individually rare, the fact that these nine diseases are irreversibly progressive over 10 to 30 years, severely impairing and ultimately fatal, usually implicating the full-time patient support by a caregiver for long time periods, makes their economic and social impact quite significant. This has led several researchers worldwide to investigate the pathogenic mechanism(s) and therapeutic strategies for polyQ diseases. Although research in the field has grown notably in the last decades, we are still far from having an effective treatment to offer patients, and the decision of which compounds should be translated to the clinics may be very challenging. In this review, we provide a comprehensive and critical overview of the most recent drug discovery efforts in the field of polyQ diseases, including the most relevant findings emerging from two different types of approaches-hypothesis-based candidate molecule testing and hypothesis-free unbiased drug screenings. We hereby summarize and reflect on the preclinical studies as well as all the clinical trials performed to date, aiming to provide a useful framework for increasingly successful future drug discovery and development efforts.Project ON.2 SR&TD Integrated Program (NORTE-07-0124-FEDER-000021), co-funded by North Portugal Regional Operational Program (ON.2-O Novo Norte), under the National Strategic Reference Framework, through the European Regional Development Fund (ERDF) and also supported by Fundação para a Ciência e Tecnologia through the project POCI-01-0145-FEDER-016818 (PTDC/NEU-NMC/3648/2014)info:eu-repo/semantics/publishedVersio

Cognitive decline in Huntington's disease expansion gene carriers

BACKGROUND: In Huntington's Disease (HD) cognitive decline can occur before unequivocal motor signs become apparent. As cognitive decline often starts early in the course of the disease and has a progressive nature over time, cognition can be regarded as a key target for symptomatic treatment. The specific progressive profile of cognitive decline over time is unknown. OBJECTIVE: The aim of this study is to quantify the progression of cognitive decline across all HD stages, from pre-motormanifest to advanced HD, and to investigate if CAG length mediates cognitive decline. METHODS: In the European REGISTRY study 2669 HD expansion gene carriers underwent annual cognitive assessment. General linear mixed models were used to model the cognitive decline for each cognitive task across all disease stages. Additionally, a model was developed to evaluate the cognitive decline based on CAG length and age rather than disease stage. RESULTS: There was significant cognitive decline on all administered tasks throughout pre-motormanifest (close to estimated disease onset) participants and the subsequent motormanifest participants from stage 1 to stage 4. Performance on the Stroop Word and Stroop Color tests additionally declined significantly across the two pre-motormanifest groups: far and close to estimated disease onset. The evaluation of cognition performance in relation to CAG length and age revealed a more rapid cognitive decline in participants with longer CAG length than participants with shorter CAG length over time. CONCLUSION: Cognitive performance already shows decline in pre-motormanifest HD gene expansion carriers and gradually worsens to late stage HD. HD gene expansion carriers with certain CAG length have their own cognitive profile, i.e., longer CAG length is associated with more rapid decline

Cognitive decline in Huntington's disease expansion gene carriers

Background: In Huntington's Disease (HD) cognitive decline can occur before unequivocal motor signs become apparent. As cognitive decline often starts early in the course of the disease and has a progressive nature over time, cognition can be regarded as a key target for symptomatic treatment. The specific progressive profile of cognitive decline over time is unknown.Objective: The aim of this study is to quantify the progression of cognitive decline across all HD stages, from pre-motormanifest to advanced HD, and to investigate if CAG length mediates cognitive decline.Methods: In the European REGISTRY study 2669 HD expansion gene carriers underwent annual cognitive assessment. General linear mixed models were used to model the cognitive decline for each cognitive task across all disease stages. Additionally, a model was developed to evaluate the cognitive decline based on CAG length and age rather than disease stage.Results: There was significant cognitive decline on all administered tasks throughout pre-motormanifest (close to estimated disease onset) participants and the subsequent motormanifest participants from stage 1 to stage 4. Performance on the Stroop Word and Stroop Color tests additionally declined significantly across the two pre-motormanifest groups: far and close to estimated disease onset.The evaluation of cognition performance in relation to CAG length and age revealed a more rapid cognitive decline in participants with longer CAG length than participants with shorter CAG length over time.Conclusion: Cognitive performance already shows decline in pre-motormanifest HD gene expansion carriers and gradually worsens to late stage HD. HD gene expansion carriers with certain CAG length have their own cognitive profile, i.e., longer CAG length is associated with more rapid decline.</br

Huntington's Disease. Prevalence and Psychological Indicators of Pain

Background Huntington's disease (HD) is a genetic neurodegenerative condition that involves impairments in movement, cognition, and mood. Research is lacking in HD with regard to the prevalence of pain and the relationships between psychological factors and pain. The aim of this research was to investigate the prevalence of pain and identify the psychological factors associated with pain severity in people with HD. Methods This data‐mining study used data from 1474 people who participated in the European Huntington's Disease Network (EHDN) REGISTRY study. Pain severity was measured using the Medical Outcome Study 36‐item short‐form health survey. Separate ordinal regression analyses were conducted with participant‐rated and interviewer‐rated psychological measures (the Hospital Anxiety and Depression Scale–Snaith Irritability Scale and the Unified Huntington's Disease Rating Scale). The psychological factors considered were anxiety, depression, irritability, aggression, low self‐esteem, and apathy. Results The prevalence of pain in the total sample was 41% (stage I, 42%; stage II, 44%; stage III, 39%; stages IV and V, 50%). After controlling for confounding variables, pain severity was significantly associated with participant‐rated anxiety and depression. Interviewer‐rated anxiety, depression, and irritability also were significantly associated with severity of pain after controlling for confounding variables. Conclusions This research confirmed that pain is indeed an issue for people with HD, particularly during the later stages of the disease. Caregivers and health professionals should consider the possibility that people with HD might be experiencing pain, particularly if they are showing signs of anxiety, depression, or irritability