Predicting Progression in Parkinson's Disease Using Baseline and 1-Year Change Measures.

BackgroundImproved prediction of Parkinson's disease (PD) progression is needed to support clinical decision-making and to accelerate research trials.ObjectivesTo examine whether baseline measures and their 1-year change predict longer-term progression in early PD.MethodsParkinson's Progression Markers Initiative study data were used. Participants had disease duration ≤2 years, abnormal dopamine transporter (DAT) imaging, and were untreated with PD medications. Baseline and 1-year change in clinical, cerebrospinal fluid (CSF), and imaging measures were evaluated as candidate predictors of longer-term (up to 5 years) change in Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) score and DAT specific binding ratios (SBR) using linear mixed-effects models.ResultsAmong 413 PD participants, median follow-up was 5 years. Change in MDS-UPDRS from year-2 to last follow-up was associated with disease duration (β= 0.351; 95% CI = 0.146, 0.555), male gender (β= 3.090; 95% CI = 0.310, 5.869), and baseline (β= -0.199; 95% CI = -0.315, -0.082) and 1-year change (β= 0.540; 95% CI = 0.423, 0.658) in MDS-UPDRS; predictors in the model accounted for 17.6% of the variance in outcome. Predictors of percent change in mean SBR from year-2 to last follow-up included baseline rapid eye movement sleep behavior disorder score (β= -0.6229; 95% CI = -1.2910, 0.0452), baseline (β= 7.232; 95% CI = 2.268, 12.195) and 1-year change (β= 45.918; 95% CI = 35.994,55.843) in mean striatum SBR, and 1-year change in autonomic symptom score (β= -0.325;95% CI = -0.695, 0.045); predictors in the model accounted for 44.1% of the variance.ConclusionsBaseline clinical, CSF, and imaging measures in early PD predicted change in MDS-UPDRS and dopamine-transporter binding, but the predictive value of the models was low. Adding the short-term change of possible predictors improved the predictive value, especially for modeling change in dopamine-transporter binding

The Parkinson's progression markers initiative (PPMI) - establishing a PD biomarker cohort.

ObjectiveThe Parkinson's Progression Markers Initiative (PPMI) is an observational, international study designed to establish biomarker-defined cohorts and identify clinical, imaging, genetic, and biospecimen Parkinson's disease (PD) progression markers to accelerate disease-modifying therapeutic trials.MethodsA total of 423 untreated PD, 196 Healthy Control (HC) and 64 SWEDD (scans without evidence of dopaminergic deficit) subjects were enrolled at 24 sites. To enroll PD subjects as early as possible following diagnosis, subjects were eligible with only asymmetric bradykinesia or tremor plus a dopamine transporter (DAT) binding deficit on SPECT imaging. Acquisition of data was standardized as detailed at www.ppmi-info.org.ResultsApproximately 9% of enrolled subjects had a single PD sign at baseline. DAT imaging excluded 16% of potential PD subjects with SWEDD. The total MDS-UPDRS for PD was 32.4 compared to 4.6 for HC and 28.2 for SWEDD. On average, PD subjects demonstrated 45% and 68% reduction in mean striatal and contralateral putamen Specific Binding Ratios (SBR), respectively. Cerebrospinal fluid (CSF) was acquired from >97% of all subjects. CSF (PD/HC/SWEDD pg/mL) α-synuclein (1845/2204/2141) was reduced in PD vs HC or SWEDD (P < 0.03). Similarly, t-tau (45/53) and p-tau (16/18) were reduced in PD versus HC (P < 0.01).InterpretationPPMI has detailed the biomarker signature for an early PD cohort defined by clinical features and imaging biomarkers. This strategy provides the framework to establish biomarker cohorts and to define longitudinal progression biomarkers to support future PD treatment trials

Digital mobility sub-study in the Parkinson's Progressive Marker Initiative (PPMI) study

This poster details the gait sub-study project in PPMI. The sub-study aims to test the feasibility and validity of digital mobility data for enrichment of the prodromal screening and to assess the sensitivity of these measures to early phase progression in prodromal and recently diagnosed patients with Parkinson’s disease. The poster details the protocol and the initial preliminary results of the first 21 participants. The post5er was presented in the Movement Disorders Society Conference held in Copenhagen, Denmark in Sept 2023

Identifying prodromal symptoms at high specificity for Parkinson’s disease

IntroductionTo test drugs with the potential to prevent the onset of Parkinson’s disease (PD), it is key to identify individuals in the general population at high risk of developing PD. This is often difficult because most of the clinical markers are non-specific, common in PD but also common in older adults (e.g., sleep problems).ObjectiveWe aimed to identify the clinical markers at high specificity for developing PD by comparing individuals with PD or prodromal PD to healthy controls.MethodsWe investigated motor and non-motor symptoms (Movement Disorder Society Unified Parkinson’s Disease Rating Scale Part 1 and 2 items) in 64 prodromal PD and 422 PD individuals calculating the odds ratios, adjusting for age and gender, for PD and prodromal PD versus 195 healthy controls. Symptoms at high specificity were defined as having an adjusted odds ratio ≥ 6.ResultsConstipation had an adjusted odds ratio, 6.14 [95% CI: 2.94–12.80] showing high specificity for prodromal PD, and speech difficulties had an adjusted odds ratio, 9.61 [95% CI: 7.88–48.81] showing high specificity for PD. The proportion of participants showing these specific markers was moderate (e.g., prevalence of constipation was 43.75% in prodromal PD, and speech difficulties was 33.89% in PD), suggesting these symptoms may make robust predictors of prodromal PD and PD, respectively.DiscussionClinical markers at high specificity for developing PD could be used as tools in the screening of general populations to identify individuals at higher risk of developing PD

Anticipating Tomorrow: Tailoring Parkinson's Symptomatic Therapy Using Predictors of Outcome

Background: Although research into Parkinson's disease (PD) subtypes and outcome predictions has continued to advance, recommendations for using outcome prediction to guide current treatment decisions remain sparse. Objectives: To provide expert opinion‐based recommendations for individually tailored PD symptomatic treatment based on knowledge of risk prediction and subtypes. Methods: Using a modified Delphi approach, members of the Movement Disorders Society (MDS) Task Force on PD subtypes generated a series of general recommendations around the question: “Using what you know about genetic/biological/clinical subtypes (or any individual‐level predictors of outcome), what advice would you give for selecting symptomatic treatments for an individual patient now, based on what their subtype or individual characteristics predict about their future disease course?” After four iterations and revisions, those recommendations with over 75% endorsement were adopted. Results: A total of 19 recommendations were endorsed by a group of 13 panelists. The recommendations primarily centered around two themes: (1) incorporating future risk of cognitive impairment into current treatment plans; and (2) identifying future symptom clusters that might be forestalled with a single medication. Conclusions: These recommendations provide clinicians with a framework for integrating future outcomes into patient‐specific treatment choices. They are not prescriptive guidelines, but adaptable suggestions, which should be tailored to each individual. They are to be considered as a first step of a process that will continue to evolve as additional stakeholders provide new insights and as new information becomes available. As individualized risk prediction advances, the path to better tailored treatment regimens will become clearer

Safety, Pharmacokinetics, and Pharmacodynamics of Oral Venglustat in Patients with Parkinson's Disease and a GBA Mutation: Results from Part 1 of the Randomized, Double-Blinded, Placebo-Controlled MOVES-PD Trial

BACKGROUND: Glucocerebrosidase gene (GBA) mutations influence risk and prognosis of Parkinson's disease (PD), possibly through accumulation of glycosphingolipids, including glucosylceramide (GL-1). Venglustat is a novel, brain penetrant glucosylceramide synthase inhibitor. OBJECTIVE: Evaluate venglustat pharmacology, safety, and tolerability in patients with PD and GBA mutations (GBA-PD). METHODS: Part 1 of the phase 2 MOVES-PD trial (NCT02906020) was a randomized, double-blinded, placebo-controlled, dose-escalation study performed in six countries. Eligible participants included Japanese and non-Japanese patients aged 18-80 years with PD diagnosis and heterozygous GBA mutation. Participants were randomized to three doses of once-daily oral venglustat or placebo and were followed up to 36 weeks (Japanese participants: 52 weeks). Primary endpoint was venglustat safety and tolerability versus placebo. Secondary and exploratory endpoints included venglustat pharmacokinetics and pharmacodynamics. RESULTS: Participants (N = 29) received venglustat (Japanese, n = 9; non-Japanese, n = 13) or placebo (n = 3; n = 4). Eight (89%) Japanese and 12 (92%) non-Japanese venglustat-treated participants experienced at least one adverse event (AE) versus two (67%) and four (100%) participants from the respective placebo groups. Most AEs were mild or moderate; no serious AEs or deaths occurred. Two venglustat-treated non-Japanese participants discontinued due to AEs (confusional state and panic attack). Over 4 weeks, venglustat exposure in plasma and cerebrospinal fluid (CSF) increased, and GL-1 levels in plasma and CSF decreased, both in a dose-dependent manner. At the highest dose, CSF GL-1 decreased by 72.0% in Japanese and 74.3% in non-Japanese participants. CONCLUSION: Venglustat showed favorable safety and tolerability in MOVES-PD Part 1 and target engagement was achieved in CSF

Seeking progress in disease modification in Parkinson disease.

OBJECTIVE: Disease modification in Parkinson disease (PD) has remained an elusive goal, in spite of large investments over several decades. Following a large meeting of experts, this review article discusses the state of the science, possible reasons for past PD trials failures to demonstrate disease-modifying benefit, and potential solutions. METHODS: The National Institute of Neurological Disorders and Stroke (NINDS) convened a meeting including leaders in the field and representatives of key stakeholder groups to discuss drug therapy with the goal of disease modification in PD. RESULTS: Important lessons can be learned from previous attempts, as well as from other fields. The selection process for therapeutic targets and agents differs among various organizations committed to therapeutic development. The areas identified as critical to target in future research include the development of relevant biomarkers, refinements of the targeted patient populations, considerations of novel trial designs, and improving collaborations between all stakeholders. CONCLUSIONS: We identify potential barriers to progress in disease modification for Parkinsons and propose a set of research priorities that may improve the likelihood of success

Genetic Testing in Parkinson's Disease

Genetic testing for persons with Parkinson's disease is becoming increasingly common. Significant gains have been made regarding genetic testing methods, and testing is becoming more readily available in clinical, research, and direct-to-consumer settings. Although the potential utility of clinical testing is expanding, there are currently no proven gene-targeted therapies, but clinical trials are underway. Furthermore, genetic testing practices vary widely, as do knowledge and attitudes of relevant stakeholders. The specter of testing mandates financial, ethical, and physician engagement, and there is a need for guidelines to help navigate the myriad of challenges. However, to develop guidelines, gaps and controversies need to be clearly identified and analyzed. To this end, we first reviewed recent literature and subsequently identified gaps and controversies, some of which were partially addressed in the literature, but many of which are not well delineated or researched. Key gaps and controversies include: (1) Is genetic testing appropriate in symptomatic and asymptomatic individuals without medical actionability? (2) How, if at all, should testing vary based on ethnicity? (3) What are the long-term outcomes of consumer- and research-based genetic testing in presymptomatic PD? (4) What resources are needed for clinical genetic testing, and how is this impacted by models of care and cost-benefit considerations? Addressing these issues will help facilitate the development of consensus and guidelines regarding the approach and access to genetic testing and counseling. This is also needed to guide a multidisciplinary approach that accounts for cultural, geographic, and socioeconomic factors in developing testing guidelines.</p