Publications by authors named "Grachev I"

Purpose: Pridopidine is an investigational drug for Huntington disease (HD). Pridopidine was originally thought to act as a dopamine stabilizer. However, pridopidine shows highest affinity to the sigma-1 receptor (S1R) and enhances neuroprotection via the S1R in preclinical studies.

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Background: Open-HART was an open-label extension of HART, a randomized, double-blind, placebo-controlled study of pridopidine in Huntington disease (HD). Previously, we reported safety and exploratory efficacy data after 36 months of treatment with pridopidine 45 mg twice daily. In the interim, emerging data suggests pridopidine may have neuroprotective effects mediated by sigma-1 receptor agonism.

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Previous studies have demonstrated the feasibility and promise of wearable sensors as objective measures of motor impairment in Parkinson disease and essential tremor. However, there are few published studies that have examined such an application in Huntington disease (HD). This report provides an evaluation of the potential to objectively quantify chorea in HD patients using wearable sensor data.

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Background: A growing number of clinical trials use various sensors and smartphone applications to collect data outside of the clinic or hospital, raising the question to what extent patients comply with the unique requirements of remote study protocols. Compliance is particularly important in conditions where patients are motorically and cognitively impaired. Here, we sought to understand patient compliance in digital trials of two such pathologies, Parkinson's disease (PD) and Huntington disease (HD).

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Background: Previous trials have shown that pridopidine might reduce motor impairment in patients with Huntington's disease. The aim of this study was to ascertain whether higher doses of pridopidine than previously tested reduce motor symptoms in a dose-dependent manner while maintaining acceptable safety and tolerability.

Methods: PRIDE-HD was a randomised, placebo-controlled, phase 2, dose-ranging study in adults (aged ≥21 years) with Huntington's disease at outpatient clinics in 53 sites across 12 countries (Australia, Austria, Canada, Denmark, France, Germany, Italy, Poland, Russia, the Netherlands, the UK, and the USA).

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Aims: SD-1077, a selectively deuterated precursor of dopamine (DA) structurally related to L-3,4-dihydroxyphenylalanine (L-DOPA), is under development for treatment of motor symptoms of Parkinson's disease. Preclinical models have shown slower metabolism of central deuterated DA. The present study investigated the peripheral pharmacokinetics (PK), metabolism and safety of SD-1077.

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Background: Open-HART is an open-label extension of HART, a randomized, placebo-controlled, dose-ranging, parallel-group study.

Objective: To evaluate safety and exploratory efficacy of open-label pridopidine over 36 months in subjects with Huntington's disease (HD).

Methods: Open-HART subjects were treated with pridopidine 45 mg twice daily (BID).

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Article Synopsis
  • In vivo imaging of brain β-amyloid can help assess suspected Alzheimer's disease.
  • The study evaluated the effectiveness of positron emission tomography (PET) with flutemetamol injection for detecting β-amyloid by using actual neuritic plaque levels as a benchmark.
  • Conducted at multiple sites in the U.S. and England, the study involved terminally ill patients aged 55 and older, focusing on the accuracy of PET scans in identifying β-amyloid presence prior to their autopsy.
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Introduction: Diagnostic effectiveness of Ioflupane I 123 injection (DaTSCAN™, DaTscan™, or [123I]FP-CIT or ioflupane [(123)I]) SPECT imaging, was assessed in patients with clinically uncertain parkinsonian syndrome (CUPS).

Methods: We investigated the association between subject's Hoehn & Yahr (H&Y) stage, Mini-Mental State Examination (MMSE), age, and motor symptom subgroups and diagnostic performance of ioflupane [(123)I] imaging. Phase 4 study data were used to calculate sensitivity, specificity, positive and negative predictive value, and accuracy in 92 CUPS subjects, using 1-year clinical diagnosis after ioflupane [(123)I] imaging as reference standard.

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Objectives: To pool clinical trials of similar design to assess overall sensitivity and specificity of ioflupane I123 injection (DaTSCAN or ioflupane ((123)I)) to detect or exclude a striatal dopaminergic deficit disorder (SDDD), such as parkinsonian syndrome and dementia with Lewy bodies.

Design: Pooled analysis of three phase 3 and one phase 4 clinical trials. These four trials were selected because they were the four studies used for the US new drug application to the Food and Drug Administration (FDA).

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Ioflupane is an analog of cocaine that binds reversibly with high affinity to the dopamine transporter (DaT) protein, a marker for presynaptic terminals in dopaminergic nigrostriatal neurons. Ioflupane (123)I Injection is also known as DaTscan or DaTSCAN ((123)I-ioflupane is also called (123)I-2-β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)nortropane or (123)I-FP-CIT). The diagnostic efficacy of DaTscan has been described elsewhere.

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Article Synopsis
  • * A review of five multicenter studies showed high sensitivity and specificity for Ioflupane among various clinical scenarios, with improved diagnostic performance observed as time passed from initial to confirmed clinical diagnoses.
  • * Overall, the diagnostic performance of Ioflupane was comparable among on-site and blinded independent readers, with excellent agreement between different readers, indicating strong reliability in its use for diagnosis.
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Parkinson's disease (PD), the second-most common neurodegenerative disease, is characterized by motor and nonmotor symptoms. PD is often misdiagnosed; inappropriate treatment due to misdiagnosis has undesired consequences, as does delayed diagnosis. Unfortunately, most people with PD receive a diagnosis only after motor symptoms have emerged, by which time 40% to 60% of dopamine neurons have already been lost.

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Introduction: PET imaging of amyloid-β (Aβ) in vivo holds promise for aiding in earlier diagnosis and intervention in Alzheimer's disease (AD) and mild cognitive impairment. AD-like Aβ pathology is a common comorbidity in patients with idiopathic normal pressure hydrocephalus (iNPH). Fifty patients with iNPH needing ventriculo-peritoneal shunting or intracranial pressure monitoring underwent [18F]flutemetamol PET before (N = 28) or after (N = 22) surgery.

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Unlabelled: BACKGOUND/OBJECTIVE: To determine the level of association between uptake of the amyloid positron emission tomography (PET) imaging agent [(18)F]flutemetamol and the level of amyloid-β measured by immunohistochemical and histochemical staining in a frontal cortical region biopsy site.

Methods: Seventeen patients with probable normal pressure hydrocephalus (NPH) underwent prospective [(18)F]flutemetamol PET and subsequent frontal cortical brain biopsy during ventriculoperitoneal shunting. Tissue amyloid-β was evaluated using the monoclonal antibody 4G8, thioflavin S and Bielschowsky silver stain.

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The diagnosis of movement disorders including Parkinson's disease (PD) and essential tremor is determined through clinical assessment. The difficulty with diagnosis of early PD has been highlighted in several recent clinical trials. Studies have suggested relatively high clinical diagnostic error rates for PD and essential tremor.

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Background And Purpose: This study determined the correlation between uptake of the amyloid positron emission tomography (PET) imaging agent [(18) F]flutemetamol and amyloid-β measured by immunohistochemical and histochemical staining in a frontal cortical biopsy.

Methods: Fifteen patients with possible normal pressure hydrocephalus (NPH) and previous brain biopsy obtained during intracranial pressure monitoring underwent [18F]flutemetamol PET. Seven of these patients also underwent [11C] Pittsburgh compound B (PiB) PET.

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Molecular imaging techniques developed to 'visualize' amyloid in vivo represent a major achievement in Alzheimer's disease (AD) research. This pooled analysis of four studies determined the level of association between uptake of the fibrillar amyloid β positron emission tomography (PET) imaging agent [(18)F]flutemetamol (Pittsburgh Compound B analog with a 5.5 times longer half-life to enable it to be used in the clinical setting) and neuritic plaques and fibrillar amyloid β measured by pathologic staining of cortical region biopsy samples.

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Purpose: The primary objectives of this study were to assess the safety of [(18)F]flutemetamol injection and determine the level of association between the quantitative estimates of brain uptake of [(18)F]flutemetamol and the quantitative immunohistochemical (IHC) estimates of amyloid levels in cerebral cortex biopsies obtained during shunt placement in patients with normal pressure hydrocephalus (NPH).

Procedures: Parietal lobe biopsies were obtained from 12 subjects (mean (SD), 71 (8.1) years), during shunt placement for NPH.

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What Is Known And Objective: Preladenant (SCH420814, MK-3814) is a highly selective orally bioavailable non-methylxanthine adenosine 2A (A(2A) ) receptor antagonist under investigation for the treatment for Parkinson's disease. This study evaluated the safety, tolerability and pharmacokinetics of preladenant at single and multiple doses for the first time in humans.

Methods: These were two randomized, double-blind, placebo-controlled, ascending-dose studies, one evaluating single rising preladenant doses (5-200 mg) compared with placebo and the other evaluating multiple rising preladenant doses (10-200 mg once daily over 10 days) compared with placebo.

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Background: An accurate diagnosis is important for timely and adequate treatment in patients with clinically uncertain parkinsonian syndrome (CUPS).

Objective: The objective of this study was to assess safety and changes in clinical management, diagnosis and quality of life (QoL) at 4 and 12 weeks following DaTscan (ioflupane [(123)I] injection) imaging in patients with CUPS.

Methods: This randomized, open-label, single-dose, multicenter trial was carried out in patients with CUPS who were randomized to either a DaTscan imaging group or to a control group without imaging.

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Realizing that 60% to 80% of dopaminergic nigrostriatal neurons are nonfunctional at the time of clinical diagnosis, there is an emerging consensus that disease-modifying treatments should be initiated in the earliest stages of Parkinson's disease (PD). To date, clinical trial designs and metrics in PD have been focused on motor symptoms as the core feature of the clinical disease. To identify earlier or "pre-motor" populations in PD, new markers have been proposed.

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Background: This study assessed the impact of DaTscan on clinical management, diagnosis, confidence of diagnosis (CoD), quality of life (QoL), health resource use (HRU) and safety during a 1-year follow-up in patients with clinically uncertain parkinsonian syndromes (CUPS).

Methods: A total of 19 university hospital centres in Europe and the USA participated in this open-label, single-dose, prospective, clinical trial in patients with CUPS who were randomised to a DaTscan imaging group or to a no-imaging (control) group. The proportion of patients with changes in clinical management, diagnosis, CoD, QoL and HRU from baseline through 1 year post-DaTscan was compared between groups.

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The aim of this study was to evaluate the effect of food on the oral bioavailability of preladenant, a novel adenosine A(2A) receptor antagonist. This open-label, randomized, single-dose, 2-way crossover study evaluated the effects of a high-fat, high-calorie meal on the pharmacokinetics of preladenant and its metabolite (SCH434748) following oral administration of a single 25-mg preladenant capsule to 24 healthy subjects. When administered with food, the time of maximum concentration (T(max)) of preladenant was prolonged compared with administration in the fasting state.

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