A Phase 3, Double-Blind, Randomized, Placebo-Controlled, Parallel-Group, 27-Week Trial to Evaluate the Efficacy, Safety, and Tolerability of Two Fixed Doses of Tavapadon in Early Parkinson’s Disease (TEMPO-1 TRIAL)

– Male and female participants aged 40 to 80 years, inclusive, at the time of signing
the ICF (Informed consent form).

– Participants with a diagnosis of that is consistent with the UK Parkinson’s Disease
Society Brain Bank diagnostic criteria, with bradykinesia and motor asymmetry

– Participants with modified Hoehn and Yahr stage 1, 1.5, or 2

– Participants with disease duration (from time of diagnosis) of less than (<) 3 years and disease progression in the 3 years before signing the informed consent form (ICF) - Participants with an MDS-UPDRS Part II score greater than or equal to (>=)2 and Part
III score >=10 at the screening visit

– Participants with early PD who, in the opinion of the investigator, require
pharmacologic intervention for disease management

– Participants who are treatment naïve or have a history of prior incidental treatment
with dopaminergic agents (including L-Dopa and dopamine receptor agonist medications)
for <3 months and not within 2 months of signing the ICF. Prior and concurrent use of Monoamine oxidase (MAO)-B inhibitors is permitted if use was initiated > 90 days
before signing of the ICF and the dosage will remain stable for the duration of the
trial (i.e, no change in the MAO-B inhibitor dose is permitted during the trial)

– Participants who are willing and able to refrain from any PD medications that are not
permitted by the protocol (including dopaminergic agents) throughout participation in
the trial

Exclusion

– Participants with a history or clinical features consistent with essential tremor,
atypical or secondary parkinsonian syndrome (including, but not limited to,
progressive supra nuclear palsy, multiple system atrophy, cortico-basal degeneration,
or drug-induced or post stroke parkinsonism)

– Participants with a history of nonresponse or insufficient response to L-Dopa or 2 or
more other antiparkinsonian drugs at therapeutic dosages

– Participants with a history or current diagnosis of a clinically significant impulse
control disorder (Disruptive, Impulse Control, and Conduct Disorder per DSM-5)

– Participants with the presence of or history of brain tumor, hospitalization for
severe head trauma, epilepsy (as defined by the International League Against
Epilepsy), or seizures

– Participants with a history of psychosis or hallucinations within the previous 12
months based on medical records or participant/caregiver feedback

– Participants who answer “yes” on the C-SSRS Suicidal Ideation Item 4 or Item 5 (Active
Suicidal Ideation with Some Intent to Act, Without Specific Plan, or Active Suicidal
Ideation with Specific Plan and Intent) and whose most recent episode meeting the
criteria for C-SSRS Item 4 or Item 5 occurred within the last 6 months, OR
Participants who answer “yes” on any of the 5 C-SSRS Suicidal Behavior Items (actual
attempt, interrupted attempt, aborted attempt, preparatory acts, or behavior) and
whose most recent episode meeting the criteria for any of these 5 C-SSRS Suicidal
Behavior Items occurred within the last 2 years, OR Participants who, in the opinion
of the investigator, present a serious risk of suicide.

– Participants with substance abuse or dependence disorder, including alcohol,
benzodiazepines, and opioids, but excluding nicotine, within the past 6 months (180
days)

– Participants with dementia or cognitive impairment that, in the judgement of the
investigator, would exclude the participant from understanding the ICF or
participating in the trial

– Participants with any condition that could possibly affect drug absorption, including
bowel resections, bariatric weight loss surgery, or gastrectomy (this does not include
gastric banding)

– Participants with a history of neuroleptic malignant syndrome

– Participants who are currently receiving moderate or strong CYP3A4 inducers or CYP3A4
inhibitors (except for topical administration)

– Participants with a positive urine drug screen for illicit drugs are excluded and may
not be retested or rescreened. Participants with a positive urine drug screen
resulting from use of marijuana (any Tetrahydrocannabinol [THC]-containing product),
prescription, or over-the-counter medications or products that, in the investigator’s
documented opinion, do not signal a clinical condition that would impact the safety of
the participant or interpretation of the trial results may continue evaluation for the
trial following consultation and approval by the medical monitor

– Participants with a Montreal Cognitive Assessment (MoCA) score <26.