GDNF Gene Therapy for Multiple System Atrophy

Inclusion Criteria: * Male and female 35-75 years of age (inclusive) * Clinical diagnosis of MSA, parkinsonian type with symptoms onset sporadic, progressive and \> 30 years of age * Less than 5 years from MSA parkinsonian diagnosis with expected survival more than 3 years * Stable anti-parkinsonian medication regimen * Ability to walk a distance of 25 feet with or without an assistive device Exclusion Criteria: * Presence of idiopathic Parkinson's disease (PD) or any PD-related mutation or other neurological diseases * Presence of dementia, psychosis, substance abuse or poorly controlled depression * Prior brain surgery (i.e., deep brain stimulator implantation) or other brain imaging abnormalities * History of cancer or poorly controlled medical conditions that would increase surgical risk * Received investigational agent within 12 weeks * Inability to tolerate laying flat in an MRI and/or allergy to gadolinium NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.