To Evaluate the Pharmacokinetics (PK) and Safety of Tavapadon in Participants With Mild and Moderate Hepatic Impairment Compared to Participants With Normal Hepatic Function

Key Inclusion Criteria:

• Body mass index of ≥17.5 to 42.0 0 kilograms per meter square (kg/m^2), inclusive, and a total body weight >50 kilograms (kg) [110 pounds (lbs)].
• Must meet the criteria for Class A or B of the modified Child-Pugh classification.
• Stable hepatic disease defined as no clinically significant change in disease status in the last 28 days prior to the screening visit.
• Previous alcohol abuse is permitted provided that the participant is willing and able to follow lifestyle guidelines and has a negative breath alcohol test at Screening and Check-in (Day -1).

Key Exclusion Criteria:

• Receipt of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) vaccine or booster within 7 days of planned dosing.
• Have recently been diagnosed with symptomatic Coronavirus Disease 2019 (COVID-19) or test positive for COVID-19 within 30 days prior to signing the informed consent form (ICF).
• Taking any prohibited medication prior to randomization or likely to require prohibited concomitant therapy.
• Has received study drug in a clinical trial of Tavapadon within 12 months of signing the ICF.
• Acute hepatitis.
• Grade ≥2 hepatic encephalopathy.
• Participants who have received an organ transplant or are currently waiting for an organ transplant and are listed on the national transplant list.
• Primary biliary cholangitis or primary sclerosing cholangitis.

Note: Other protocol-defined Inclusion/Exclusion criteria may apply.