Noninterventional Study Evaluating Parkinson's Disease Diary Use

Open to people ages 39-70

• ≥39 to ≤70 years of age at signing of informed consent
• Diagnosis of clinically established PD as defined by the Movement Disorder Society (MDS) Clinical Diagnostic Criteria for PD
• Marked levodopa responsiveness at screening per investigator's judgment (eg, an estimated ≥30% improvement of MDS-UPDRS Part III score in the off-medication versus on-medication state)
• A minimum of 3 years and a maximum of 18 years from time of PD diagnosis to the date of screening
• Receiving optimized and stable PD medical therapy for ≥1 month prior to screening or demonstrated intolerance to PD medications per investigator's judgment in agreement with the medical monitor
• ≥3 hours of average daily OFF-time assessed within 3 months of screening by PD diary or per investigator's judgment
• Hoehn and Yahr Stage of 1 to 3 while on PD medication assessed within 3 months of screening or at screening
• Normal cognition as determined by the investigator after review of relevant testing (eg, Montreal Cognitive Assessment score of ≥26, or ≥22 if no significant cognitive impairment as determined by neuropsychological testing)

• PD with risk of recurrent falls or only tremor-based symptoms
• Diagnosis of primary mitochondrial disorder, epilepsy, stroke, multiple sclerosis, or clinical features suggestive of a neurodegenerative disease other than PD such as Alzheimer's disease
• Any available evidence inconsistent with dopamine deficiency (eg, 18F-DOPA positron emission tomography [PET] or dopamine transporter single-photon emission computed tomography [DAT-SPECT] imaging if performed)
• Moderately severe dyskinesia per investigator's judgment
• Receiving dopamine receptor-blocking agents, including typical neuroleptics, prochlorperazine, and metoclopramide at the time of screening or within 3 months prior to screening
• Treatment with intrajejunal or subcutaneous infusion therapies for PD within 2 months of screening
• History of PD therapy with deep brain stimulation, lesion therapy, gene therapy, or cell therapy
• Prior surgical or radiation therapy to the brain or spinal cord
• Receipt of another investigational therapy or device within 2 years of screening unless approved by the medical monitor