Safety and Efficacy of Deutetrabenazine at High versus Lower Daily Dosages in the ARC-HD Study to Treat Chorea in Huntington Disease.

Background: Huntington disease (HD) is a progressive neurodegenerative disease that causes psychiatric and neurological symptoms, including involuntary and irregular muscle movements (chorea). Chorea can disrupt activities of daily living, pose safety issues, and may lead to social withdrawal. The vesicular monoamine transporter 2 inhibitors tetrabenazine, deutetrabenazine, and valbenazine are approved treatments that can reduce chorea.

What Huntington's Disease Patients Say About Their Illness: An Online Direct-to-Participant Pilot Study.

Background: Direct-to-participant online reporting facilitates the conduct of clinical research by increasing access and clinically meaningful patient engagement.

Objective: We assessed feasibility of online data collection from adults with diagnosed Huntington's disease (HD) who directly reported their problems and impact in their own words.

Methods: Data were collected online from consenting United States residents who self-identified as 1) having been diagnosed with Huntington's disease, 2) able to ambulate independently, and 3) self-sufficient for most daily needs.

Safety and efficacy of valbenazine for the treatment of chorea associated with Huntington's disease (KINECT-HD): a phase 3, randomised, double-blind, placebo-controlled trial.

Background: Valbenazine is a highly selective vesicular monoamine transporter 2 (VMAT2) inhibitor approved for treatment of tardive dyskinesia. To address the ongoing need for improved symptomatic treatments for individuals with Huntington's disease, valbenazine was evaluated for the treatment of chorea associated with Huntington's disease.

Methods: KINECT-HD (NCT04102579) was a phase 3, randomised, double-blind, placebo-controlled trial, performed in 46 Huntington Study Group sites in the USA and Canada.

The Safety of Deutetrabenazine for Chorea in Huntington Disease: An Open-Label Extension Study.

Background: Deutetrabenazine is approved in the USA, China, Australia, Israel, Brazil, and South Korea for the treatment of chorea associated with Huntington disease.

Objective: We aimed to evaluate the long-term safety and tolerability of deutetrabenazine for the treatment of Huntington disease.

Methods: This open-label, single-arm, multi-center study included patients who completed a double-blind study (Rollover) and patients who converted overnight from a stable tetrabenazine dose (Switch).

Design of a virtual longitudinal observational study in Parkinson's disease (AT-HOME PD).

Objective: The expanding power and accessibility of personal technology provide an opportunity to reduce burdens and costs of traditional clinical site-centric therapeutic trials in Parkinson's disease and generate novel insights. The value of this approach has never been more evident than during the current COVID-19 pandemic. We sought to (1) establish and implement the infrastructure for longitudinal, virtual follow-up of clinical trial participants, (2) compare changes in smartphone-based assessments, online patient-reported outcomes, and remote expert assessments, and (3) explore novel digital markers of Parkinson's disease disability and progression.

Phenotype-genotype discrepancies in the prospective Huntington at-risk observational study.

Objective: To examine phenotype-genotype discrepancies (PGDs) wherein genotype-concealed and prospective judgments of the motor onset of Huntington disease (HD) occurred among at-risk adults who had nonexpanded (<37) cytosine-adenine-guanine (CAG) trinucleotide DNA repeats.

Methods: We examined the prospective clinical assessments of investigators who were kept unaware of individual CAG lengths in the Prospective Huntington At-Risk Observational Study (PHAROS) who enrolled and followed undiagnosed adults at risk for HD who chose not to learn their gene status. Subjects ( = 1001) at 43 Huntington Study Group research sites in the US and Canada were evaluated prospectively and systematically between 1999 and 2009.

The choice not to undergo genetic testing for Huntington disease: Results from the PHAROS study.

Rates of genetic testing in Huntington disease (HD) are lower than was predicted before direct DNA testing became available. Clinicians often do not have in-depth conversations with people at risk who chose not to test. We queried 733 research subjects who chose not to learn their HD gene status when enrolling in the Prospective Huntington At-Risk Observational Study, carried out between 1999 and 2008.

Safety of Converting From Tetrabenazine to Deutetrabenazine for the Treatment of Chorea.

Importance: Tetrabenazine is efficacious for chorea control; however, tolerability concerns exist. Deutetrabenazine, a novel molecule that reduces chorea, was well tolerated in a double-blind, placebo-controlled study.

Objectives: To evaluate the safety and explore the efficacy of conversion from tetrabenazine to deutetrabenazine in patients with chorea associated with Huntington disease (HD).

Effect of Deutetrabenazine on Chorea Among Patients With Huntington Disease: A Randomized Clinical Trial.

Importance: Deutetrabenazine is a novel molecule containing deuterium, which attenuates CYP2D6 metabolism and increases active metabolite half-lives and may therefore lead to stable systemic exposure while preserving key pharmacological activity.

Objective: To evaluate efficacy and safety of deutetrabenazine treatment to control chorea associated with Huntington disease.

Design, Setting, And Participants: Ninety ambulatory adults diagnosed with manifest Huntington disease and a baseline total maximal chorea score of 8 or higher (range, 0-28; lower score indicates less chorea) were enrolled from August 2013 to August 2014 and randomized to receive deutetrabenazine (n = 45) or placebo (n = 45) in a double-blind fashion at 34 Huntington Study Group sites.

Clinical-Genetic Associations in the Prospective Huntington at Risk Observational Study (PHAROS): Implications for Clinical Trials.

Importance: Identifying measures that are associated with the cytosine-adenine-guanine (CAG) expansion in individuals before diagnosis of Huntington disease (HD) has implications for designing clinical trials.

Objective: To identify the earliest features associated with the motor diagnosis of HD in the Prospective Huntington at Risk Observational Study (PHAROS).

Design, Setting, And Participants: A prospective, multicenter, longitudinal cohort study was conducted at 43 US and Canadian Huntington Study Group research sites from July 9, 1999, through December 17, 2009.

Characterization of the Huntington intermediate CAG repeat expansion phenotype in PHAROS.

Objectives: We aimed to describe the clinical phenotype conferred by the intermediate-length huntingtin allele CAG repeat expansion in a population-based study.

Methods: The Prospective Huntington At Risk Observational Study (PHAROS) enrolled adults at risk for Huntington disease (HD). They were assessed approximately every 9 months with the Unified Huntington's Disease Rating Scale (UHDRS) by investigators unaware of participants' gene status.

A randomized, placebo-controlled trial of latrepirdine in Huntington disease.

Objectives: To evaluate the safety and tolerability of latrepirdine in Huntington disease (HD) and explore its effects on cognition, behavior, and motor symptoms.

Design: Double-blind, randomized, placebo-controlled trial.

Setting: Multicenter outpatient trial.

Fear of health insurance loss among individuals at risk for Huntington disease.

Genetic testing in Huntington disease, an inherited ultimately fatal neurodegenerative disorder, is infrequent despite wide availability. Factors influencing the decision to pursue testing are largely unknown. We conducted a prospective longitudinal observational study of 1,001 individuals in North America who were at risk for Huntington disease who had not pursued genetic testing prior to enrollment.

Detection of Huntington's disease decades before diagnosis: the Predict-HD study.

Objective: The objective of the Predict-HD study is to use genetic, neurobiological and refined clinical markers to understand the early progression of Huntington's disease (HD), prior to the point of traditional diagnosis, in persons with a known gene mutation. Here we estimate the approximate onset and initial course of various measurable aspects of HD relative to the time of eventual diagnosis.

Methods: We studied 438 participants who were positive for the HD gene mutation, but did not yet meet the diagnostic criteria for HD and had no functional decline.

Beyond disgust: impaired recognition of negative emotions prior to diagnosis in Huntington's disease.

Previous studies of emotion recognition suggest that detection of disgust relies on processing within the basal ganglia and insula. Research involving individuals with symptomatic and pre-diagnostic Huntington's disease (HD), a disease with known basal ganglia atrophy, has generally indicated a relative impairment in recognizing disgust. However, some data have suggested that recognition of other emotions (particularly fear and anger) may also be affected in HD, and a recent study found fear recognition deficits in the absence of other emotion-recognition impairments, including disgust.

Verbal episodic memory declines prior to diagnosis in Huntington's disease.

Previous studies of verbal episodic memory in pre-diagnostic Huntington's disease (HD) have yielded mixed results; some evidence suggests that memory decline is evident prior to the onset of pronounced neurological signs of HD, whereas other data indicate that memory function remains normal throughout the pre-diagnostic period. This study examines verbal episodic memory in a sample of CAG expanded individuals who have not yet been clinically diagnosed, and who represent a wide range of points along the continuum from health to disease. The Hopkins Verbal Learning Test-Revised (HVLT-R) was administered to 479 participants (428 with the HD CAG expansion and 51 without), and performance was compared to neurobiological indices of disease progression, including a DNA-based estimate of proximity to clinical diagnosis, magnetic resonance imaging (MRI) measures of striatal volume, and neurologist ratings of motor signs.

Preparing for preventive clinical trials: the Predict-HD study.

Background: The optimal design and outcome measures for preventive clinical trials in neurodegenerative diseases are unknown.

Objective: To examine measures that may be associated with disease in the largest cohort ever recruited of prediagnosed individuals carrying the gene expansion for Huntington disease (HD).

Design: The Predict-HD study is a multicenter observational research study in progress at 17 sites in the United States, 4 in Canada, and 3 in Australia.

Interrater agreement in the assessment of motor manifestations of Huntington's disease.

With prospects improving for experimental therapeutics aimed at postponing the onset of illness in preclinical carriers of the Huntington's disease (HD) gene, we assessed agreement among experienced clinicians with respect to the motor manifestations of HD, a relevant outcome measure for preventive trials in this population. Seventy-five clinicians experienced in the evaluation of patients with early HD and six non-clinicians were shown a videotape compiled from the film archives of the United States-Venezuela Collaborative HD Research Project. Observers were asked to rate a 2-3-minute segment of the motor examination for each of 17 at-risk subjects.

Predictors of nursing home placement in Huntington disease.

Objective: To determine whether motor, behavioral, or psychiatric symptoms in Huntington disease (HD) predict skilled nursing facility (SNF) placement.

Methods: Subjects were participants in the Huntington Study Group's Unified Huntington Disease Rating Scale Database (Rochester, NY) between January 1994 and September 1999. Specific motor, psychiatric, and behavioral variables in subjects residing at home and in SNF were analyzed using chi2 and Student's t-tests.

A randomized, controlled trial of remacemide for motor fluctuations in Parkinson's disease.

Background: Preclinical studies suggest that glutamate antagonists help ameliorate motor fluctuations in patients with PD treated with levodopa.

Methods: In a multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study, the authors assessed the safety, tolerability, and efficacy of the glutamate receptor blocker remacemide hydrochloride in 279 patients with motor fluctuations treated with levodopa. The primary objective was to assess the short-term tolerability and safety of four dosage levels of remacemide during 7 weeks of treatment.

Rate of functional decline in Huntington's disease. Huntington Study Group.

Objective: To determine the rate of functional decline in a large cohort of patients with Huntington's disease (HD) followed at 43 sites by the Huntington Study Group (HSG).

Methods: The annual rate of functional decline was measured using the Total Functional Capacity Scale (TFC) and the Independence Scale (IS) in 960 patients with definite HD followed prospectively for a mean of 18.3 months.