A Study to Determine if BHV-8000 is Effective, Safe and Tolerable as a Treatment for Adults Living With Early Parkinson's Disease

A study to determine if BHV-8000 is efficacious, safe and tolerable in adults diagnosed with early Parkinson's disease. The study will consist of a 48-week double-blind treatment phase followed by a 48-week open-label phase.

Key Inclusion Criteria: * Male or female participants 40 to 80 years of age, inclusive, at the time of informed consent. * Meet the diagnostic criteria for "Probable PD" as assessed on the Movement Disorder Society (MDS) Clinical Diagnostic Criteria for PD as assessed by the Investigator. * Have a clinician-documented diagnosis of idiopathic PD with an onset within 2 years of the Screening Visit Key Exclusion Criteria: * Medical history indicating a Parkinsonian syndrome other than idiopathic PD, including, but not limited to, progressive supranuclear gaze palsy, multiple system atrophy, drug-induced Parkinsonism, essential tremor, or primary dystonia. * Diagnosis of clinically significant central nervous system (CNS) disease other than PD. * Participants who are current smokers (defined as smoking \[in any form, e.g., tobacco smoke, electronic cigarettes, etc.\] ) * Treatment with PD medication(s) * Any other condition(s) that may compromise participant safety, interfere with study conduct, or jeopardize the potential proper interpretation of study results, in the opinion of the investigator.