Emmanuelle Pourcher

Preladenant in patients with Parkinson's disease and motor fluctuations: a phase 2, double-blind, randomised trial

BACKGROUND Preladenant is an adenosine 2A (A₂(A)) receptor antagonist. In animal models of Parkinsons disease, preladenant monotherapy improves motor function without causing dyskinesia and, as an adjunct to levodopa, it improves motor function without worsening dyskinesia. We aimed to assess the efficacy and safety of preladenant in patients with Parkinsons disease and motor fluctuations who were receiving levodopa and other antiparkinsonian drugs. METHODS In this phase 2, dose-finding trial, patients with Parkinsons disease who were receiving levodopa were enrolled and treated at 44 sites in 15 countries between December, 2006, and November, 2008. Assignment to treatment was done centrally with an interactive voice response system, according to a block randomisation schedule that was computer generated by the sponsor. Patients were assigned to receive 1, 2, 5, or 10 mg oral preladenant twice daily, or matching placebo for 12 weeks. Patients, study staff, investigators, and all sponsor personnel were masked to treatment assignment. The primary outcome was change in mean daily off time from baseline to week 12, as assessed by home diaries. Efficacy analysis included all patients who received at least one dose of study drug and had data for assessments after baseline. This trial is registered with ClinicalTrials.gov, number NCT00406029. FINDINGS 253 patients were randomised to receive preladenant (1 mg [n=49], 2 mg [n=49], 5 mg [n=49], 10 mg [n=57]) or placebo (n=49), of whom 234 on preladenant (1 mg [n=47], 2 mg [n=48], 5 mg [n=45], 10 mg [n=49]) and placebo (n=45) were eligible for the efficacy analysis. Mean daily off time from baseline to week 12 was reduced versus placebo in patients on 5 mg preladenant (difference -1·0 h, 95% CI -2·1 to 0·0; p=0·0486) and 10 mg preladenant (-1·2 h, -2·2 to -0·2; p=0·019). Changes in mean daily off time versus placebo were not significant for 1 mg preladenant (0·2 h, -0·9 to 1·2; p=0·753) or 2 mg preladenant (-0·7 h, -1·7 to 0·3; p=0·162). The most common adverse events in the combined preladenant group versus placebo were worsening of Parkinsons disease (22 [11%] vs 4 [9%]), somnolence (20 [10%] vs 3 [6%]), dyskinesia (18 [9%] vs 6 [13%]), nausea (17 [9%] vs 5 [11%]), constipation (15 [8%] vs 1 [2%]), and insomnia (15 [8%] vs 4 [9%]). INTERPRETATION 5 and 10 mg preladenant twice daily might be clinically useful to reduce off time in patients with Parkinsons disease and motor fluctuations. FUNDING Schering-Plough, a subsidiary of Merck.

New data on the genetics of Parkinson's disease.

We investigated the clinical and metabolic characteristics of Parkinsonian patients whose illness started before the age of 40. A pilot study of 32 of our own such cases revealed the existence of 3 subgroups: 1. Post-Encephalitic, 2. Onset and course with predominant tremor, 3. Onset and course with akinesia and rigidity. In this early onset group of patients, there was a 46% incidence of familial cases (as opposed to 10-15% in the general Parkinson populations). The cases with tremor onset had a high prevalence of essential tremor in their families, while those with an akineto-rigid onset had a high familial incidence of other cases of Parkinsons Disease. Familial grey hair, hypertension, diabetes and thyroidopathies appeared to be in higher than expected frequency.

Donepezil in Parkinson's Disease Dementia: A Randomized, Double-Blind Efficacy and Safety Study

Parkinsons disease dementia (PDD) is associated with cholinergic deficits. This report presents an efficacy and safety study of the acetylcholinesterase inhibitor donepezil hydrochloride in PDD. PDD patients (n = 550) were randomized to donepezil (5 or 10 mg) or placebo for 24 weeks. Coprimary end points were the Alzheimers Disease Assessment Scale–cognitive subscale (ADAS‐cog) and Clinicians Interview‐Based Impression of Change plus caregiver input (CIBIC+; global function). Secondary end points measured executive function, attention, activities of daily living (ADLs), and behavioral symptoms. Safety and tolerability were assessed. ADAS‐cog mean changes from baseline to week 24 (end point) were not significant for donepezil in the intent‐to‐treat population by the predefined statistical model (difference from placebo: −1.45, P = .050, for 5 mg; −1.45, P = .076, for 10 mg). Alternative ADAS‐cog analysis, removing the treatment‐by‐country interaction term from the model, revealed significant, dose‐dependent benefit with donepezil (difference from placebo: −2.08, P = .002, for 5 mg; −3.31, P < .001, for 10 mg). The 10‐mg group, but not the 5‐mg group, had significantly better CIBIC+ scores compared with placebo (3.7 vs 3.9, P = .113, for 5 mg; 3.6 vs 3.9, P = .040, for 10 mg). Secondary end points—Mini–Mental State Exam; Delis–Kaplan Executive Function System; Brief Test of Attention, representing cognitive functions particularly relevant to PDD—showed significant benefit for both donepezil doses (P ≤ .007). There were no significant differences in ADLs or behavior. Adverse events were more common with donepezil but mostly mild/moderate in severity. Although the study did not achieve its predefined primary end points, it presents evidence suggesting that donepezil can improve cognition, executive function, and global status in PDD. Tolerability was consistent with the known safety profile of donepezil.

Tozadenant (SYN115) in patients with Parkinson's disease who have motor fluctuations on levodopa: a phase 2b, double-blind, randomised trial

BACKGROUND Many patients with Parkinsons disease have motor fluctuations despite treatment with available drugs. Tozadenant (SYN115) is an oral, selective adenosine A2A receptor antagonist that improves motor function in animal models of Parkinsons disease. We aimed to assess the safety and efficacy of tozadenant as an adjunct to levodopa in patients with Parkinsons disease who have motor fluctuations on levodopa. METHODS We did an international, multicentre, phase 2b, randomised, double-blind, placebo-controlled, parallel-group, dose-finding clinical trial of tozadenant in levodopa-treated patients with Parkinsons disease who had motor fluctuations (at least 2·5 h off-time per day). Eligible patients were randomly assigned via a computer-generated randomisation schedule to receive tozadenant 60, 120, 180, or 240 mg or matching placebo twice daily for 12 weeks. All study management, site personnel, and patients were masked to treatment assignment. The primary outcome was change from baseline to week 12 in hours per day spent in the off-state (assessed from Parkinsons disease diaries completed by patients). This study is registered at ClinicalTrials.gov, number NCT01283594. FINDINGS Of 420 randomised patients (mean age 63·3 [SD 8·3] years; mean duration of Parkinsons disease 8·7 [4·7] years), 403 provided post-baseline diary data and 337 completed study treatment. Compared with placebo, mean daily off-time was significantly reduced in the combined tozadenant 120 mg twice-daily and 180 mg twice-daily group (-1·1 h, 95% CI -1·8 to -0·5; p=0·0006), the tozadenant 120 mg twice-daily group (-1·1 h, -1·8 to -0·4; p=0.0039), and the tozadenant 180 mg twice-daily group (-1·2 h, -1·9 to -0·4; p=0·0039). The most common adverse events in these groups were dyskinesia (seven [8%] of 84 patients in the placebo group, 13 [16%] of 82 in the 120 mg twice-daily group, and 17 [20%] of 85 in the 180 mg twice-daily group), nausea (three [4%], 9 [11%], and ten [12%]), and dizziness (one [1%], four [5%], and 11 [13%]). Tozadenant 60 mg twice daily was not associated with a significant reduction in off-time, and tozadenant 240 mg twice daily was associated with an increased rate of discontinuation because of adverse events (17 [20%] of 84 patients). INTERPRETATION Tozadenant at 120 or 180 mg twice daily was generally well tolerated and was effective at reducing off-time. Further investigation of tozadenant treatment in phase 3 trials is warranted. FUNDING Biotie Therapies.

Ropinirole and pramipexole, the new agonists

Ropinirole and pramipexole are non-ergoline dopamine agonists which are relatively specific for the D2 family of dopamine receptors. They have side-effect profiles linked to peripheral and central dopaminergic stimulation, amenable to tolerance through a slow titration or the addition of domperidone in sensitive patients. They do not have the uncommon but problematic ergot-related side effects of bromocriptine and pergolide. Ropinirole and pramipexole have both been shown to be efficacious when used as monotherapy in early Parkinsons disease (PD), and have been suggested as being less likely than levodopa to lead to the early development of motor fluctuations and dyskinesias in this clinical setting. They have also been shown to be useful as adjunctive therapy to levodopa in advanced PD and to have a levodopa-sparing effect in these patients. Dose equivalents amongst the available dopamine agonists is difficult to know with certainty but has been estimated as follows: 30 mg of bromocriptine, 15 mg of ropinirole, 4.5 mg of pramipexole, and 3.0 mg of pergolide.

Randomized trial of IPX066, carbidopa/levodopa extended release, in early Parkinson's disease

OBJECTIVE IPX066 is an extended release carbidopa/levodopa formulation designed to rapidly attain and maintain therapeutic plasma concentrations for a prolonged duration, allowing dosing intervals of approximately 6 h. The objective was to assess the efficacy, safety, and impact on quality of life of IPX066 in the treatment of levodopa-naive Parkinsons disease (PD) patients. METHODS This was a randomized, double-blind, placebo-controlled, 30-week study of 381 levodopa-naïve patients assigned to placebo or IPX066 containing 145, 245 or 390 mg of levodopa administered three times daily (TID). The primary efficacy measure was change from Baseline in Unified Parkinsons Disease Rating Scale (UPDRS) activities of daily living (Part II) + motor scores (Part III), at 30 weeks. Secondary outcome measures included UPDRS total and subscores, patient and clinician global impressions (PGI-I, CGI-I), and the Parkinsons Disease Questionnaire (PDQ-39). RESULTS All IPX066 dosages were superior to placebo throughout the study and at 30 weeks (P < 0.0001). The mean improvement in UPDRS Parts II + III at 30 weeks compared to baseline was 11.7, 12.9, and 14.9 points for the three dosages and 0.6 points for placebo (P < 0.0001, all dosages). PDQ-39 total scores improved with IPX066 (P ≤ 0.034, all dosages). The most commonly reported adverse events with IPX066 included nausea, dizziness, and headache. No unexpected drug-related serious adverse events were reported. CONCLUSION IPX066 provided significant clinical benefits at the three dosages tested compared to placebo and was well tolerated in levodopa-naive PD patients. Of the dosages tested, IPX066 145 mg TID appeared to provide the best overall balance between efficacy and safety.

Compulsive habits in restless legs syndrome patients under dopaminergic treatment

Since the introduction of levodopa therapy and dopaminergic replacement therapy to abate symptoms of idiopathic Parkinsons disease, repetitive compulsive behaviors have been reported and are now considered to be drug-related response complications. As dopamine (DA) agonists are the licensed treatment in Restless Legs Syndrome (RLS), a survey was conducted to determine the extent to which patients with RLS present compulsive behaviors. The aim of this study was to investigate the relationship between DA agonists and the occurrence of motor or behavioral compulsions, stress, depression, and sleep disturbance in RLS patients. A questionnaire was mailed three times, at four-month intervals over a period of 8 months to all patients of the Quebec Memory and Motor Skills Disorders Clinic diagnosed with RLS. In addition to recording all medication information for RLS treatment, patients were assessed on the International Restless Legs Syndrome Study Group Rating Scale (IRLS), the Beck Depression Inventory-II (BDI-II), the Sleep Scale from the Medical Outcomes Study (MOS) and on a visual analog scale for current level of stress. A section pertaining to hobby, mania, and compulsion was also included. Analyses are based on 97 out of 151 patients (64.2%) with RLS who returned the three questionnaires. Twelve patients (12.4%) on stable DA agonist therapy (average dose 0.52+/-0.59 mg Pramipexole equivalent) developed a new compulsive behavioral repertoire. Eating (3 women, 1 man), buying food or clothes (2 women, 1 man), trichotillomania (1 woman, 1 man), and gambling (1man) were among the compulsions developed under DA treatment. In addition, two women presented new tic-like phenomena. In contrast to the RLS patients without compulsive behaviors (53 treated with DA agonist; 32 untreated), those with compulsive habits reported experiencing more stress, depression and sleep problems. Patients with RLS with mood and stress states may be at greater risk of developing compulsive behaviors while receiving standard dosage DA agonist treatment. These behaviors are clearly linked to short-term satisfaction and underline the role of dopaminergic mesolimbic stimulation in the reinforcement process of rewarding behavioral sequences.

Effects of 24 wk of treadmill training on gait performance in Parkinson's disease.

PURPOSE Recent studies suggest that walking on a treadmill improves gait, mobility, and quality of life of patients with Parkinsons disease (PD). Still, there is a need for larger-scale randomized controlled studies that demonstrate the advantages of treadmill training (TT) with control groups that receive similar amounts of attention. Moreover, to date, no study has combined speed and incline as parameters of progression. The aim of the study was to evaluate the effects of 24 wk of TT, with and without the use of incline, on gait, mobility and quality of life in patients with PD. METHODS The sample comprised 34 patients with PD, at the Hoehn and Yahr stage 1.5 or 2. Participants were randomized to speed TT, mixed TT, and control groups. The intervention consisted of 72 one-hour exercise sessions for 24 wk. The main outcome measures are the Movement Disorder Society-Unified Parkinsons Disease Rating Scale, the 39-item Parkinsons Disease Questionnaire, spatiotemporal parameters of gait and 6-min walking distance. The measures were taken at baseline, mid-term and after 6 months. RESULTS Both TT groups improved in terms of speed, cadence, and stride length during self-selected walking conditions at the study end point. Both groups also showed improvements in distance traveled. Only the Mixed TT group improved their quality of life. The Control group showed no progress. CONCLUSIONS Participants in this study showed significant improvements in walking speed and walking endurance after 6 months of TT. Improvements were observed after 3 months of intensive TT and persisted at 6 months. It appears that individuals with poorer baseline performance may benefit most from TT.

Field Testing of an Ataxia Scoring and Staging System

The authors present a simple system for disability scoring and functional staging of an ataxic patient, based on modifications of a previous scheme advocated by De Falco and collaborators (1979). This system was tested under field conditions in 47 ataxic subjects and found to be useful and functional.

The fate of the large striatal interneurons expressing calretinin in Huntington's disease.

Huntingtons disease (HD) is characterized by the atrophy of the striatum due to losses of projection neurons, while interneurons are relatively spared. However, little is known about the fate of the large interneurons that express calretinin (Cr) in HD. We addressed this issue by applying a double immunofluorescent labeling technique to postmortem striatum from HD patients and controls. We compared the distribution and density of Cr-positive (+) interneurons and their degree of choline acetyltransferase (ChAT) coexpression in normal and HD cases. Large interneurons containing only Cr, ChAT, or both occurred in the normal human striatum and a twofold decrease in the density of Cr+/ChAT+ and Cr-/ChAT+ neurons was recorded in HD striatum compared to controls. However, studies undertaken with neurokinin-1 receptor as a marker of large Cr+ and ChAT+ neurons revealed that these neurons are selectively spared in HD. Hence, the apparent decrease in the number of Cr+/ChAT+ and Cr-/ChAT+ neurons in HD is better explained by a diminution in the expression of Cr and ChAT than by the degeneration of these cells. Altogether, our data suggest that neurodegenerative processes at play in HD affect the expression of Cr and ChAT in the large striatal interneurons without causing their death.