A Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of BIIB094 in Adults With Parkinson's Disease

Key Inclusion Criteria:

• Ability to understand the purpose and risks of the study and provide signed anddated informed consent and authorization to use confidential health information inaccordance with national and local participant privacy regulations.

• Diagnosed with PD within 7 years at the time of initial enrollment (i.e., at time ofSAD enrollment for rollover participants), without major motor fluctuations ordyskinesia that may interfere with study treatment and assessments in the opinion ofthe investigator after consultation with the Sponsor.

• Modified Hoehn and Yahr Stage ≤ 3.

Key Exclusion Criteria:

• Montreal Cognitive Assessment (MoCA) score less than (<) 23, dementia, or othersignificant cognitive impairment that, in the opinion of the Investigator, wouldinterfere with study evaluation.

• History of any brain surgery for PD or a history of focused ultrasound treatment atany time; or history of neuromodulation procedures.

• Transient ischemic attack or stroke or any unexplained loss of consciousness within 1 year before Screening.

• History of unstable angina, myocardial infarction, chronic heart failure, orclinically significant conduction abnormalities within 1 year before Screening.

• Poorly controlled diabetes mellitus, as defined by having dosage adjustment ofdiabetic medication within 3 months before dosing (Day 1) or glycosylated hemoglobinvalue greater than or equal to (≥) 8 percent (%) at Screening.

• History or positive test result at Screening for human immunodeficiency virus.

• History or positive test result at Screening for hepatitis C virus antibody.

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