Safety Study of AADC Gene Therapy (VY-AADC01) for Parkinson's Disease (AADC)

Inclusion Criteria:

• Diagnosed with idiopathic Parkinson's disease
• Disease duration of at least 5 years or more
• Adequate duration of levodopa therapy
• Modified Hoehn and Yahr Staging of at least 2.5 in the OFF state
• Candidate for surgical intervention because of disabling motor complications.
• UPDRS Part III (total motor) score ≥ 25 and a maximum of 60 in the OFF state.
• Unequivocal responsiveness to dopaminergic therapy.
• Stable Parkinson's symptoms and medication regimen for at least 4 weeks prior to screening examination.
• Ability to comprehend and sign the informed consent.
• Normal Laboratory values prior to surgery.
• Neutralizing AAV2 antibody titer ≤ 1:1200
• Ability to travel to study visits alone or able to designate a caregiver.
• Subject agrees to defer any neurological surgery, including deep brain stimulation, until after completing the 12 month study visit (unless recommended by study neurologist).
• Subject agrees to not participate in any other therapeutic intervention study for 12 months after surgery.
• Subject agrees to not have any vaccinations within 30 days of surgery.

Exclusion Criteria:

• Atypical or secondary parkinsonism, including but not limited to symptoms believed to be due to trauma, brain tumor, infection, cerebrovascular disease, other neurological disease, or to drugs, chemicals or toxins.
• Presence of dementia as defined by a Mattis Dementia Rating Scale-Second Edition (MDRS-2) of less than 130 at screening.
• Presence or history of psychosis, with the exception of mild, benign hallucinations believed in the judgment of the investigators to be related to Parkinson's medications.
• Presence of severe depression as measured by Beck Depression Inventory II (BDI-II) > 28 or a history of a major affective disorder within 5 years of screening examination.
• Current suicidal ideation or suicide attempt within 5 years of screening examination.
• History of substance abuse within 2 years of screening examination.
• Brain imaging abnormalities in the striatum or other regions that would substantially increase risk of surgery.
• Contraindication to MRI and/or gadoteridol.
• Coagulopathy or inability to temporarily stop any anticoagulation or antiplatelet prior to surgery.
• Prior brain surgery including deep brain stimulation, infusion therapies or any other brain surgery.
• Prior gene transfer.
• History of stroke, poorly controlled or significant cardiovascular disease, diabetes or any other acute or chronic medical condition.
• History of malignancy other than treated carcinoma in situ within three years of screening evaluation.
• Clinically apparent or laboratory-detected infection.
• Prior or current treatment with any investigational agent within 2 months of screening evaluation.
• Chronic immunosuppressive therapy, including chronic steroids, immunotherapy, cytotoxic therapy and chemotherapy.
• Pregnant and lactating women.
• Subject with reproductive capacity who is unwilling to use barrier contraception.
• Any medical condition that is likely to lead to disability during the course of the study and interfere with confound study assessments
• Any factors, medical, or social, which would likely cause the subject to be unable to follow the study protocol, including geographical inaccessibility.
• Ongoing treatments such as, neuroleptic medications, apomorphine, or levodopa infusion therapy (Duodopa®).