Parkinson's Disease (PD)Phase 1PDCS-01NCT07267065
AAV2-hAADC for Parkinson's Disease (PDCS-01)
A Phase 1 study testing AAV2-hAADC in people with Parkinson's Disease (PD) and Early Onset Parkinson Disease, run by Russell Lonser at 1 site in United States.
Trial summary
This study is looking at whether a gene therapy called AAV2-hAADC is safe and may help people with Parkinson's Disease. AAV2-hAADC is intended to increase the levels of dopamine in your brain. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Parkinson's Disease (PD), Early Onset Parkinson Disease
- What is being tested?
- AAV2-hAADC
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 9 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Nov 2026to 1 Mar 2029
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male and female adults 18-75 years of age (inclusive), at the time of signing the informed consent.
- Diagnosed with idiopathic Parkinson's Disease as defined by the following:
- Presence of bradykinesia PLUS any of the following: i. Rigidity ii. Resting tremor iii. Postural instability
- Disease duration since diagnosis of >3 years.
- Patient reported symptom onset prior to the age of 50 (inclusive).
- Modified Hoehn \& Yahr Staging ≥2.5 in the practically defined OFF medication state (≥ 12 hours from last dose of anti-parkinsonian medications)
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- Disabling motor complications with an average of ≥3 hours of OFF time per day during waking hours within 7 days of the screening visit as confirmed by the Parkinson's Disease (PD) diary.
- International Parkinson and Movement Disorder Society (MDS) Unified Parkinson's Disease Rating Scale (UPDRS) Part III (total motor) score ≥25 in the clinically defined OFF state.
- Unequivocal responsiveness to dopaminergic therapy for a minimum of 1 year, including a 30% or greater improvement in the UPDRS III (motor score) between ON and OFF states, as determined by the Investigator after overnight withdrawal of Parkinson's medications.
- In the judgment of the Investigator, a stable, optimal regimen of Parkinson's medications for at least 4 weeks prior to screening evaluation.
- In the judgment of the Investigator, stable Parkinson's features and symptoms for at least 4 weeks prior to screening evaluation.
- Laboratory values prior to surgery:
- Platelets >100E9/L (transfusion independent)
- Prothrombin time (PT)/partial thromboplastin time (PTT) in normal range and international normalized ratio (INR) ≤1.3
- Absolute neutrophil count >1.5E9/L
- Hemoglobin >10.0 g/dL
- Aspartate aminotransferase or alanine aminotransferase <2.5U/L × the upper limit of normal
- Total bilirubin <2.5 mg/dL
- Serum creatinine ≤1.5 mg/dL
- Hematocrit >34%
- White blood cell count <12E9/L
- Estimated glomerular filtration rate ≥30 mL/min.
- Medically and cognitively capable of comprehending and signing the informed consent, as well as undergoing and complying with the surgical procedure and protocol requirements as determined by review of medical records, medical history, and clinical evaluation.
- Ability to travel to study visits alone or able to designate a care partner who agrees to accompany the participant to study visits as determined by discussion with the participant, care partner (if applicable), and Investigator.
- Agrees to defer any neurological surgery, including deep brain stimulation, until the 12-month study visit is completed.
Who cannot join
- Atypical or secondary parkinsonism, including but not limited to symptoms resulting from trauma, brain tumor, infection, cerebrovascular disease, other neurological disease, or to drugs, chemicals, or toxins, as determined by the Investigator.
- Presence of clinically significant cognitive impairment as defined by a Montreal Cognitive Assessment (MoCA) score of less than 241 at screening and/or clinical diagnosis of dementia by Investigator based on MoCA diagnostic criteria.
- Presence or history of psychosis, except for minor psychosis.
- Presence of severe depression, as indicated by a BDI-II score >28 within 5 years of screening evaluation.
- Active suicidal ideation as indicated by positive response to items 4 or 5 on the screening C-SSRS, or any history of a suicide attempt
- Presence of impulse control disorder, defined as a total score ≥10 on the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS).
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- History of substance use disorder within 2 years of screening evaluation, as determined from interview with the participant and/or review of medical records.
- Brain imaging abnormalities in the striatum or other regions that would substantially increase risk of surgery in the opinion of the investigator.
- Contraindication to magnetic resonance imaging (MRI) and/or gadolinium (e.g., ProHance [gadoteridol]).
- Coagulopathy or inability to temporarily stop any anticoagulation or antiplatelet therapy for at least 2 weeks during the perioperative period.
- Prior stereotactic brain surgery including lesioning procedures, deep brain stimulation, infusion therapies or any other prior brain surgery that could complicate the study procedure and/or negatively impact study evaluations as determined from participant interview, screening MRI, and/or review of medical records.
- Prior gene transfer, as determined from participant interview or review of medical records.
- History of stroke, poorly controlled or significant cardiovascular disease, diabetes, or any other acute or chronic medical condition that would unreasonably increase the risks of the study procedures, as determined from interview with the participant and/or review of medical records.
- History of malignancy other than treated carcinoma in situ within 3 years of screening evaluation.
- Clinically apparent or laboratory-detected infection (including acute or chronic scalp infection) at the time of screening or baseline evaluations or immediately prior to surgery that would be a contraindication to surgery.
- Prior or current treatment with any investigational agent within 5 half-lives or 30 days (whichever is shorter).
- Any factors, medical or social, which would likely cause the inability to comply with the procedures of the protocol, including completion of Parkinson's Disease (PD) diaries, frequent and prolonged study visits (including off medication visits) and travel, in the judgment of the Investigator.
- Chronic immunosuppressive therapy, including chronic steroids, immunotherapy, cytotoxic therapy, and chemotherapy as determined by participant interview and/or medical record.
- Any serious medical condition or abnormal finding on physical examination or laboratory investigation that would substantially increase the risks of the study procedures in the opinion of the investigator.
- Any medical condition that is likely to lead to disability during the study and interfere with or confound study assessments (including but not limited to orthopedic conditions, spinal disorders, neuropathy, myelopathy, severe pulmonary or cardiac disease, and compromised nutritional states), as determined from interview with the participant and/ or review of medical records.
- Pregnant and lactating women.
- Male or female with reproductive capacity who is unwilling to use barrier contraception for 6 months after surgery.
- Ongoing treatments that might interfere with interpretation of the study outcome, including antipsychotic medications, apomorphine, or levodopa infusion therapy (Duopa).
- Plans to participate in any other therapeutic intervention study within 12 months after surgery.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
The Ohio State University
Columbus, Ohio, 43210
Reagan Lovell, OSUgenetherapyresearch@osumc.edu
About this study
Official title: An Open-label Safety and Efficacy Study of AAV2-hAADC Administered by MRI-Guided Convective Infusion Using a Transfrontal Trajectory Into the Putamen and Caudate of Participants With Young Onset Parkinson's Disease
This study is looking at whether a gene therapy called AAV2-hAADC is safe and may help people with Parkinson's Disease.
AAV2-hAADC is intended to increase the levels of dopamine in your brain. It contains a virus called adeno-associated virus 2 (AAV2) that has been modified to carry the genetic code for an enzyme called Aromatic L-Amino Acid Decarboxylase, or AADC for short.
In this study, AAV2-hAADC is delivered to two parts of the brain called the putamen and the caudate. Increasing the amount of AADC gene in these parts of the brain converts more levodopa into dopamine, the chemical that is lacking in PD.
- Being tested
- AAV2-hAADC
- Keywords
- Gene Therapy, AAV2-hAADC
- Medical subject headings
- Parkinson Disease, Parkinsonian Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AAV2-hAADCDrug
The purpose of this study is to investigate AAV2-hAADC gene therapy (the study drug) for the treatment of moderately-advanced PD with motor fluctuations.
AAV2-hAADC gene therapy works by using a modified virus called adeno-associated virus 2 (AAV2). This virus is naturally-occurring and not associated with any disease. The virus' DNA has been changed so that it can deliver the human enzyme called Aromatic L-Amino Acid Decarboxylase (AADC). This enzyme converts levodopa into dopamine. AAV2-hAADC can enter brain cells and transfer the copy of the AADC gene directly into these cells. Once the gene is inside the brain cells, those cells will make AADC. By increasing the levels of AADC, we aim to increase the levels of dopamine and improve the symptoms of PD.
AAV2-hAADC will be delivered through a brain surgery to two parts of the brain called the putamen and the caudate. These parts of the brain are involved in PD.
The goal of this study is to assess whether infusing AAV2-h
| Study group | Role | What they receive |
|---|---|---|
| Dose 1 (Low Dose) | Experimental | Total Dose (vg): up to 4.2E12 Receives: Drug: AAV2-hAADC |
| Dose 2 (High Dose) | Experimental | Total Dose (vg): up to 1.3E13 Receives: Drug: AAV2-hAADC |
What is being measured
The primary outcome is the main question the study is designed to answer.
Adverse Events
Assessment of AEs or SAEs and their relationship to the study procedure and study drug (graded as definite, probable, possible, unlikely, or unrelated).
Measured: Through 3 year Follow-up
MRI findings
Intraoperative and post-operative MRI findings
Measured: Through Month 6 Follow-up
Physical Exam and labs
Changes from baseline in physical examination findings and routine clinical laboratory analysis (hematology, clinical chemistries, immunologic assessments).
Measured: Through 3 year Follow-up
C-SSRS
Changes in Columbia-Suicide Severity Rating Scale (C-SSRS) results
Measured: Through 3 year Follow-up
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Dec 2025
- Study start1 Nov 2026 (estimated)
- Primary completion1 Nov 2028 (estimated)
- Study completion1 Mar 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson's Disease (PD)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Model description
- The current study is an open-label dose escalation study investigating the safety and efficacy of 2 dose levels of AAV2-hAADC in participants with PD and fluctuating responses to levodopa. Up to 9 participants are planned to be enrolled and treated on Day 0.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 9 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Russell Lonser
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Russell Lonser, Ohio State University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07267065
- Sponsor's protocol ID
- STUDY20251920
- Acronym
- PDCS-01
- Status last verified
- Oct 2026
- First submitted
- 24 Nov 2025
- Last updated
- 3 Nov 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-label Safety and Efficacy Study of AAV2-hAADC Administered by MRI-Guided Convective Infusion Using a Transfrontal Trajectory Into the Putamen and Caudate of Participants With Young Onset Parkinson's Disease
- ClinicalTrials.gov ID
- NCT07267065
- Acronym / sponsor ID
- PDCS-01 / STUDY20251920
- Keywords
- Gene Therapy, AAV2-hAADC
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 9 participants (estimated)
- Lead sponsor
- Russell LonserUniversity, hospital or other
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 1 Nov 2028 (estimated)
- Study completion
- 1 Mar 2029 (estimated)
- First posted
- 5 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is looking at whether a gene therapy called AAV2-hAADC is safe and may help people with Parkinson's Disease.
AAV2-hAADC is intended to increase the levels of dopamine in your brain. It contains a virus called adeno-associated virus 2 (AAV2) that has been modified to carry the genetic code for an enzyme called Aromatic L-Amino Acid Decarboxylase, or AADC for short.
In this study, AAV2-hAADC is delivered to two parts of the brain called the putamen and the caudate. Increasing the amount of AADC gene in these parts of the brain converts more levodopa into dopamine, the chemical that is lacking in PD.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- The current study is an open-label dose escalation study investigating the safety and efficacy of 2 dose levels of AAV2-hAADC in participants with PD and fluctuating responses to levodopa. Up to 9 participants are planned to be enrolled and treated on Day 0.
| Arm | Type | Receives |
|---|---|---|
| Dose 1 (Low Dose) | Experimental | Drug: AAV2-hAADCTotal Dose (vg): up to 4.2E12 |
| Dose 2 (High Dose) | Experimental | Drug: AAV2-hAADCTotal Dose (vg): up to 1.3E13 |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (25 listed)
- Male and female adults 18-75 years of age (inclusive), at the time of signing the informed consent.
- Diagnosed with idiopathic Parkinson's Disease as defined by the following:
- Disease duration since diagnosis of >3 years.
- Patient reported symptom onset prior to the age of 50 (inclusive).
- Modified Hoehn \& Yahr Staging ≥2.5 in the practically defined OFF medication state (≥ 12 hours from last dose of anti-parkinsonian medications)
Key exclusion criteria (24 listed)
- Atypical or secondary parkinsonism, including but not limited to symptoms resulting from trauma, brain tumor, infection, cerebrovascular disease, other neurological disease, or to drugs, chemicals, or toxins, as determined by the Investigator.
- Presence of clinically significant cognitive impairment as defined by a Montreal Cognitive Assessment (MoCA) score of less than 241 at screening and/or clinical diagnosis of dementia by Investigator based on MoCA diagnostic criteria.
- Presence or history of psychosis, except for minor psychosis.
- Presence of severe depression, as indicated by a BDI-II score >28 within 5 years of screening evaluation.
- Active suicidal ideation as indicated by positive response to items 4 or 5 on the screening C-SSRS, or any history of a suicide attempt
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| AAV2-hAADCThe purpose of this study is to investigate AAV2-hAADC gene therapy (the study drug) for the treatment of moderately-advanced PD with motor fluctuations. AAV2-hAADC gene therapy works by using a modified virus called adeno-associated virus 2 (AAV2). This virus is naturally-occurring and not associated with any disease. The virus' DNA has been changed so that it can deliver the human enzyme called Aromatic L-Amino Acid Decarboxylase (AADC). This enzyme converts levodopa into dopamine. AAV2-hAADC can enter brain cells and transfer the copy of the AADC gene directly into these cells. Once the gene is inside the brain cells, those cells will make AADC. By increasing the levels of AADC, we aim to increase the levels of dopamine and improve the symptoms of PD. AAV2-hAADC will be delivered through a brain surgery to two parts of the brain called the putamen and the caudate. These parts of the brain are involved in PD. The goal of this study is to assess whether infusing AAV2-h | Drug | Dose 1 (Low Dose), Dose 2 (High Dose) |
Primary outcome
Adverse Events
Time frame: Through 3 year Follow-up
Assessment of AEs or SAEs and their relationship to the study procedure and study drug (graded as definite, probable, possible, unlikely, or unrelated).
MRI findings
Time frame: Through Month 6 Follow-up
Intraoperative and post-operative MRI findings
Physical Exam and labs
Time frame: Through 3 year Follow-up
Changes from baseline in physical examination findings and routine clinical laboratory analysis (hematology, clinical chemistries, immunologic assessments).
C-SSRS
Time frame: Through 3 year Follow-up
Changes in Columbia-Suicide Severity Rating Scale (C-SSRS) results
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Nov 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing AAV2-hAADC in people with Parkinson's Disease (PD) and Early Onset Parkinson Disease, run by Russell Lonser at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 25 inclusion and 24 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 3 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Adverse Events (time frame: Through 3 year Follow-up). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Nov 2026.