Pre-Gene Therapy Study in Parkinson's Disease and Multiple System Atrophy

Inclusion Criteria:

• Diagnosis of Idiopathic PD

• Diagnosis of MSA-P

• One to six years from clinical diagnosis of PD

• Less than 4 years from clinical diagnosis of MSA with expected survival >3 years

• Stable medication regimen

• Ability to walk with or without an assistive device

Exclusion Criteria:

• Movement disorder due to known cerebrovascular disease, brain tumor, trauma,exposure to parkinsonian-linked toxicants or other neurological diseases

• Presence of dementia, psychosis, substance abuse or poorly controlled depression

• Prior brain surgery (i.e. deep brain stimulation) or other brain imagingabnormalities

• History of cancer or poorly controlled medical conditions

• Receiving an investigational drug

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.