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

The objective of this study is to describe disease progression in study participants diagnosed with early Parkinson's Disease or Multiple System Atrophy - Parkinsonian Type up to 18 months as delineated by clinical and biochemical parameters.

Inclusion Criteria:Diagnosis of Idiopathic PDDiagnosis of MSA-POne to six years from clinical diagnosis of PDLess than 4 years from clinical diagnosis of MSA with expected survival >3 yearsStable medication regimenAbility to walk with or without an assistive deviceExclusion Criteria:Movement disorder due to known cerebrovascular disease, brain tumor, trauma, exposure to parkinsonian-linked toxicants or other neurological diseasesPresence of dementia, psychosis, substance abuse or poorly controlled depressionPrior brain surgery (i.e. deep brain stimulation) or other brain imaging abnormalitiesHistory of cancer or poorly controlled medical conditionsReceiving an investigational drugNOTE: Other protocol defined Inclusion/Exclusion criteria may apply.