A Study of AAV2-GDNF in Adults With Moderate Parkinson's Disease (REGENERATE-PD)

Inclusion Criteria:

Age

1. Male and female adults 45-75 years of age inclusive, at the time of signing ofinformed consent Type of Subject and Disease Characteristics

2. Diagnosed with Parkinson's disease in the past 4-10 years (inclusive) as defined bythe following:

3. Presence of bradykinesia PLUS any of the following:

• Rigidity
• Rest tremor
• Postural instability

2. Presence of motor fluctuations as measured by the PD Motor Diary

3. Stable anti-parkinsonian medication regimen for >/= 4 weeks prior to screening

4. Must demonstrate responsiveness to levodopa therapy

Exclusion Criteria:

• Known history or current evidence of medical, genetic, or neurological conditionsthat may provide an alternative to idiopathic PD diagnosis

• Presence or history of significant vascular and/or cardiovascular disease

• Presence of significant cognitive impairment, poorly controlled depression/anxiety

• Presence or history of psychosis or impulse control disorder

• History of malignancy other than treated cutaneous squamous or basal cell carcinomas

• Presence of clinically relevant conditions that could compromise surgicalsuitability and/or subject safety

• Contraindication to magnetic resonance imaging and/or use gadolinium-based contrastagents

• Prior history of brain surgery including, but no limited: DBS, pallidotomy focusedultrasound thalamotomy, or other experimental neurosurgical procedure

• Chronic immunosuppressive therapy