Parkinson's Study Group (PSG)
Overview
The Parkinson's Study Group (PSG) is a non-profit, peer-reviewed research consortium dedicated to conducting clinical trials to advance treatments for [Parkinson's disease](/diseases/parkinsons-disease) and related neurodegenerative disorders. Founded in 1985 as a network of academic medical centers across North America, the PSG has been instrumental in the development of nearly every FDA-approved Parkinson's disease medication over the past four decades[@kieburtz2013][@parkinsons].
As the premier clinical research network in the Parkinson's field, the PSG has conducted landmark trials that have shaped standard of care, from levodopa formulations to dopamine agonists, MAO-B inhibitors, and disease-modifying therapies. The group's multi-center, collaborative approach has enabled large-scale trials that would be impossible for individual institutions to conduct independently.
Mission and Objectives
The PSG's mission is to advance the understanding and treatment of Parkinson's disease and related disorders through:
- Clinical Excellence: Conducting high-quality, rigorous clinical trials following GCP guidelines
- Scientific Innovation: Investigating novel therapeutic approaches including neuroprotective and disease-modifying therapies
- Knowledge Generation: Advancing understanding of Parkinson's disease through rigorous clinical research
- Training: Developing the next generation of clinical researchers in movement disorders
- Collaboration: Fostering partnerships with other research consortia, patient organizations, and industry
Research Focus Areas
The PSG conducts trials across multiple therapeutic domains[@marsden1994][@schapira2009]:
Symptomatic Treatments
Dopaminergic Therapies
- Levodopa formulations: Optimization of carbidopa/levodopa combinations, extended-release formulations
- Dopamine agonists: Pramipexole, ropinirole, rotigotine, cabergoline
- MAO-B inhibitors: Rasagiline, selegiline, safinamide
- COMT inhibitors: Entacapone, tolcapone, opicapone
Motor Complications
The PSG has conducted extensive research on managing:
- Motor fluctuations: "Wear-off" phenomenon, delayed "on," unpredictable "off" states
- Dyskinesias: Peak-dose dyskinesias, diphasic dyskinesias, off-period dystonia
- Treatment optimization: Continuous dopaminergic delivery, deep brain stimulation timing[@nutt2001][@stocchi2005]
Non-Motor Symptoms
Research encompasses the full spectrum of non-motor features:
- Sleep disorders: REM sleep behavior disorder, insomnia, excessive daytime sleepiness
- Cognitive impairment: Executive dysfunction, dementia, visual-spatial deficits
- Autonomic dysfunction: Orthostatic hypotension, constipation, urinary dysfunction
- Psychiatric features: Depression, anxiety, psychosis, apathy[@bhatia2013][@khoo2013]
Disease-Modifying Therapies
The PSG has been at the forefront of disease-modifying therapy development:
Neuroprotective Agents
- Rasagiline: The ADAGIO trial demonstrated disease-modifying potential in early PD[@olanow2009]
- Pramipexole: The PROUD trial investigated disease-modifying effects
- Coenzyme Q10: Investigated in the QE3 trial for neuroprotection
Alpha-Synuclein-Targeted Therapies
- Immunotherapies targeting aggregated alpha-synuclein
- Small molecules inhibiting alpha-synuclein aggregation
- Gene therapy approaches targeting synuclein expression
LRRK2-Targeted Therapies
The PSG has played a critical role in LRRK2 inhibitor development:
- DNL151 (Denali) and other LRRK2 kinase inhibitors
- Genetic studies identifying LRRK2 mutation carriers for targeted trials
- Biomarker development for LRRK2-associated PD
GBA-Targeted Therapies
As the most common genetic risk factor for PD:
- GBA mutation carrier identification and characterization
- Modulator therapies targeting glucocerebrosidase
- Enhanced understanding of GBA-PD phenotype[@kieburtz2006]
Novel Therapeutic Approaches
Gene Therapy
- AAV-based delivery of GAD ( glutamic acid decarboxylase)
- AADC (amino acid decarboxylase) gene therapy
- TH (tyrosine hydroxylase) and GCH1 for dopamine synthesis
Cell Replacement Therapy
- Stem cell-derived dopamine neuron transplantation
- Research into optimal cell sources and delivery methods
Deep Brain Stimulation Optimization
- Target selection (STN vs. GPi)
- Stimulation parameter optimization
- Adaptive deep brain stimulation approaches
Immunotherapies
- Active vaccination against alpha-synuclein
- Passive antibody therapies
- Anti-inflammatory immunomodulation
Clinical Trial Network
The PSG comprises over 50 academic medical centers across North America, representing the largest coordinated clinical research network in movement disorders[@parkinsonsa]:
Founding and Headquarters
- University of Rochester (Rochester, NY) has served as the PSG headquarters since its founding
- The data coordination center manages trial operations, data management, and statistical analysis
Member Institutions
The network includes leading movement disorder centers:
Northeast Region
- [Columbia University](/institutions/columbia-university) (New York, NY)
- [University of Pennsylvania](/institutions/upenn) (Philadelphia, PA)
- [Johns Hopkins University](/institutions/johns-hopkins-university) (Baltimore, MD)
- Cornell University (New York, NY)
- Beth Israel Deaconess Medical Center (Boston, MA)
Southeast Region
- Emory University (Atlanta, GA)
- University of Florida (Gainesville, FL)
- Medical University of South Carolina (Charleston, SC)
Midwest Region
- [University of Michigan](/institutions/uni-michigan) (Ann Arbor, MI)
- Rush University (Chicago, IL)
- Washington University (St. Louis, MO)
- Cleveland Clinic (Cleveland, OH)
Southwest Region
- Baylor College of Medicine (Houston, TX)
- University of Texas Southwestern (Dallas, TX)
- University of Arizona (Phoenix, AZ)
West Coast
- [University of Washington](/institutions/university-washington) (Seattle, WA)
- Stanford University (Stanford, CA)
- University of California San Diego (San Diego, CA)
- Oregon Health and Science University (Portland, OR)
International Partnerships
The PSG collaborates internationally with:
- Parkinson's UK Discovery Club
- International Parkinson's Disease Genomics Consortium (IPDGC)
- Movement Disorder Society
- World Parkinson Congress
Landmark Clinical Trials
The PSG has contributed to numerous pivotal clinical trials that shaped Parkinson's disease treatment[@kieburtz2013][@fahn2004]:
Early Disease Trials
ELLDOPA Trial
The "Earlier vs Later Levodopa Therapy in PD" trial established that initial levodopa therapy provided superior motor symptom control compared to delayed treatment, addressing concerns about levodopa toxicity.
CALM-PD Trial
The "Comparison of the Agonist Pramipexole versus Levodopa on Motor Complications in Parkinson's Disease" trial demonstrated that initial pramipexole treatment reduced the risk of motor complications, establishing dopamine agonists as first-line therapy in younger patients[@oakley2007][@jankovic2005].
Disease Modification Trials
ADAGIO Trial
The "Attenuation of Disease Progression with Azilect" trial was a landmark delayed-start design demonstrating that rasagiline provided disease modification in early PD[@olanow2009]. This trial established the first evidence of disease modification in PD.
PROUD Trial
The "Pramipexole on Underlying Disease" trial investigated whether pramipexole had disease-modifying effects using a similar delayed-start design.
TEMPO Trial
Early studies with rasagiline established the dose-response relationship and safety profile.
Advanced Disease Trials
LEAPS Trial
The "Levodopa-Carbidopa-Intestinal Gel" trial demonstrated the efficacy of continuous intrajejunal levodopa infusion for advanced PD with motor fluctuations[@hauser2004].
DBS Trials
Pivotal trials evaluating deep brain stimulation versus best medical therapy established the surgical treatment for advanced PD.
Non-Motor Symptom Trials
- Trials for depression in PD (sertraline, venlafaxine)
- Cognitive dysfunction treatment studies
- Sleep disorder management protocols
Collaboration with Other Consortia
The PSG maintains extensive collaborative relationships[@parkinsons]:
Patient Advocacy Organizations
- [Michael J. Fox Foundation for Parkinson's Research](/institutions/michael-j-fox-foundation) (MJFF)
- [Parkinson's Foundation](/institutions/parkinsons-foundation)
- Parkinson's Action Network
Research Consortia
- [International Parkinson's Disease Genomics Consortium](/institutions/ipdgc) (IPDGC)
- [Accelerating Medicines Partnership for Parkinson's Disease](/institutions/amp-pd) (AMP-PD)
- [Parkinson's Progression Markers Initiative](/datasets/ppmi) (PPMI)
- Genetic Epidemiology of Parkinson's Disease (GEOPD)
Clinical Trial Networks
- Huntington's Disease Society of America (HDSA)
- ALS Clinical Research Learning Institute
- Critical Path for Parkinson's (CPP)
Leadership and Governance
The PSG is governed by a Steering Committee comprising leading movement disorder specialists who provide strategic direction and oversee trial operations[@kieburtz2013]:
Historical Leadership
- Dr. Karl Kieburtz (University of Rochester) - Long-serving Principal Investigator, instrumental in PSG growth
- Dr. Ira Shoulson (University of Rochester) - Founder and first chairman
- Dr. Matthew Stern (University of Pennsylvania) - Past chairman, DBS research
- Dr. Ray Kelly (University of Rochester) - Executive director
Current Leadership
The Steering Committee includes representatives from major member institutions who rotate leadership responsibilities. Standing committees include:
- Scientific Review Committee: Evaluates trial concepts and protocols
- Data Safety Monitoring Board: Independent oversight of trial safety
- Publication Committee: Manages scientific output and dissemination
- Training Committee: Oversees fellow and junior investigator development
Industry Partnerships
PSG collaborates with pharmaceutical companies including:
- AbbVie (Abbott)
- Biogen
- Denali Therapeutics
- Hoffmann-La Roche
- Lundbeck
- Merck
- Novartis
- Pfizer
- Sunovion
- Takeda
- UCB Pharma
Training and Education
The PSG invests in developing the next generation of movement disorder researchers:
Fellowship Programs
- Clinical research fellowships in PD
- Sub-specialty training in movement disorders
- Clinical trial methodology training
Educational Initiatives
- Annual meeting with scientific sessions
- Protocol development workshops
- Statistical analysis training
- Regulatory affairs education
Mentorship
Experienced PSG investigators mentor junior faculty and fellows through:
- Protocol development guidance
- Grant writing support
- Career development counseling
- Publication assistance
Impact on Parkinson's Disease Care
The PSG's contributions have fundamentally shaped modern Parkinson's disease treatment:
Therapeutic Advances
- Every FDA-approved PD medication since 1985 has involved PSG research
- Established standards for motor complication management
- Defined disease-modifying therapy development paradigms
Clinical Research Infrastructure
- Created infrastructure for multi-center PD clinical trials
- Established data standards and outcome measures
- Developed quality control processes for clinical research
Scientific Knowledge
- Generated hundreds of peer-reviewed publications
- Trained numerous clinical researchers
- Established collaborative research norms
Future Directions
The PSG continues to evolve its research agenda:
Emerging Priorities
- Biomarker-driven trials: Using biomarkers for patient stratification and outcome measurement
- Precision medicine: Targeting specific genetic subtypes (LRRK2, GBA, SNCA)
- Combination therapies: Multi-target approaches for complex disease
- Digital health: Wearable devices and remote monitoring
- Regenerative approaches: Cell and gene therapy advancement
Infrastructure Development
- Enhanced data sharing capabilities
- Expanded patient registry
- Integration with electronic health records
- Real-world evidence collection
Research Methodology Innovations
The PSG has pioneered several methodological innovations in Parkinson's disease clinical research:
Delayed-Start Trial Design: The ADAGIO trial established the delayed-start design as the gold standard for disease-modifying therapy assessment in PD. This design allows differentiation between symptomatic effects and true disease modification by comparing early-start versus delayed-start treatment groups[@olanow2009].
Biomarker Integration: The PSG has led efforts to incorporate biomarkers into clinical trials:
- Neuroimaging biomarkers (DaTscan, MRI)
- Cerebrospinal fluid biomarkers (alpha-synuclein, tau, beta-amyloid)
- Genetic biomarkers for patient stratification
- Digital biomarkers from wearable devices
Outcome Measure Validation: PSG investigators have validated novel outcome measures including:
- MDS-UPDRS (Movement Disorder Society-Unified Parkinson's Disease Rating Scale)
- Non-motor symptom scales
- Quality of life instruments
- Patient-reported outcomes
Funding and Financial Model
The PSG operates through a combination of funding sources:
Federal Funding
- National Institute of Neurological Disorders and Stroke (NINDS)
- National Institute on Aging (NIA)
- Department of Defense
- Patient-Centered Outcomes Research PCORI
Foundation Support
- Michael J. Fox Foundation
- Parkinson's Foundation
- Additional nonprofit organizations
Industry Partnerships
- Pharmaceutical company trial sponsorship
- Biotech collaborations
- Device company partnerships
Revenue Generation
- Trial coordination fees
- Data management services
- Consultation fees
Quality Assurance and Regulatory Compliance
The PSG maintains rigorous quality standards:
GCP Compliance
- International Conference on Harmonization guidelines
- FDA regulations (21 CFR Part 312)
- EMA directves
- Health Canada requirements
Site Certification
- Standardized site qualification processes
- Regular site audits
- Training and certification requirements
Data Management
- Electronic data capture systems
- Centralized statistical analysis
- Independent data monitoring
Patient Engagement and Recruitment
The PSG prioritizes patient-centric research:
Patient Advisory Board
- Input on trial design
- Outcome measure selection
- Recruitment strategies
- Results dissemination
Recruitment Innovations
- Social media engagement
- Patient registry utilization
- Minority outreach programs
- International recruitment
Retention Strategies
- Travel support programs
- Flexible visit scheduling
- Long-term follow-up protocols
Global Health Impact
The PSG's work extends beyond North America:
International Trial Expansion
- European site expansion
- Asian Pacific participation
- Latin American sites
- Global recruitment strategies
Health Equity Initiatives
- Minority enrollment goals
- Diversity in clinical trials
- Access to investigational therapies
- Community engagement
Global Standard Setting
- International guideline development
- WHO collaboration
- Policy advocacy
- Training programs worldwide
Challenges and Opportunities
The PSG faces several challenges while pursuing new opportunities:
Challenges
- Increasing trial costs
- Regulatory complexity
- Competition for patients
- Biomarker validation gaps
- Academic incentive alignment
Opportunities
- Precision medicine approaches
- Gene therapy advancements
- Digital health integration
- Biomarker development
- International collaboration
Historical Context and Evolution
The PSG has evolved significantly since its founding:
1985-1995: Foundation Years
- Initial network establishment
- First large-scale trials
- Training program development
1995-2005: Expansion Era
- Multi-center trial infrastructure
- Industry partnership growth
- International recognition
2005-2015: Innovation Period
- Disease modification trials
- Genetic subtyping research
- Biomarker integration
2015-Present: Precision Medicine Era
- LRRK2 and GBA-focused trials
- Alpha-synuclein immunotherapy
- Digital health integration
The PSG has expanded beyond idiopathic Parkinson's disease:
Atypical Parkinsonian Syndromes
- Progressive supranuclear palsy
- Multiple system atrophy
- Corticobasal degeneration
- Dementia with Lewy bodies
Parkinsonism-Plus Syndromes
- Vascular parkinsonism
- Drug-induced parkinsonism
- Post-traumatic parkinsonism
Hereditary Disorders
- Huntington's disease (collaborative)
- Spinocerebellar ataxias
- Essential tremor
Education and Training Impact
The PSG's training programs have shaped the field:
Career Development
- Movement disorder specialists trained
- Clinical trial investigators
- Academic researchers
- Industry leaders
Knowledge Dissemination
- Annual scientific meetings
- Publication of protocols
- Educational webinars
- Guidelines development
Future Vision
Looking ahead, the PSG aims to:
Accelerate disease modification: Focus on neuroprotective and regenerative approaches
Enable precision medicine: Tailor treatments to genetic and biomarker profiles
Integrate technology: Leverage digital health for monitoring and outcomes
Expand access: Increase global trial participation and diversity
Improve outcomes: Develop better therapies for all Parkinson's patientsSee Also
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Parkinson's Disease Clinical Trials](/datasets/ppmi)
- [Michael J. Fox Foundation](/institutions/michael-j-fox-foundation)
- [LRRK2 Consortium](/institutions/lrrk2-consortium)
- [GBA-PD Consortium](/institutions/gba-pd-consortium)
- [Parkinson's Foundation](/institutions/parkinsons-foundation)
- [University of Rochester](/institutions/university-of-rochester)
- [Alpha-Synuclein](/proteins/alpha-synuclein)
- [Dopamine](/neurotransmitters/dopamine)
- [Deep Brain Stimulation](/treatments/deep-brain-stimulation)
External Links
- [Parkinson's Study Group Official Website](https://www.parkinsons-study-group.org)
- [ClinicalTrials.gov: Parkinson's Disease Trials](https://clinicaltrials.gov)
- [PubMed: Parkinson's Study Group Publications](https://pubmed.ncbi.nlm.nih.gov/?term=Parkinson%27s+Study+Group)
References
[Parkinson's Study Group Official Website](https://www.parkinsons-study-group.org)
[Parkinson's Study Group Clinical Trials](https://clinicaltrials.gov)
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