A Phase 3, Double-Blind, Randomized, Placebo-Controlled, Parallel-Group, Flexible-Dose, 27-Week Trial to Evaluate the Efficacy, Safety, and Tolerability of Tavapadon as Adjunctive Therapy for Parkinson’s Disease in Levodopa-Treated Adults With Motor Fluctuations (TEMPO-3 Trial)

– Sexually active men or women of childbearing potential must agree to practice
effective birth control, or remain abstinent during the trial and for 4 weeks after
the last dose of trial treatment

– Participants who are capable of giving signed informed consent which includes
compliance with the requirements and restrictions listed in the informed consent form
(ICF) and in this protocol

– Participants who are able, in the opinion of the investigator, to understand the
nature of the trial and comply with protocol requirements, including the prescribed
dosage regimens, scheduled visits, laboratory tests, and other trial procedures

– Participants with a diagnosis of PD 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 2, 2.5, or 3 in the “on” state

– Participants with a good response to L-Dopa in the judgment of the investigator

– Participants who return a completed self-reported home diary for motor function status
(Hauser diary) during the screening period (after diary training and concordance
testing has occurred), with recordings for 2 consecutive days (ie, 2 consecutive
24-hour periods) showing at least 2 and half hours of “off” time on each of the 2 days

– Participants who are on a stable dose of L-Dopa for at least 4 weeks prior to
screening and are taking a minimum total daily dose of 400 milligram (mg) divided in
at least 4 doses per day of standard carbidopa/levodopa or divided in at least 3 doses
per day of extended-release carbidopa/levodopa capsules. The carbidopa/levodopa dose
and frequency must be maintained for the duration of the trial

– Prior and concurrent use of catechol-O-methyl transferase (COMT) inhibitors, monoamine
oxidase (MAO-B) inhibitors, amantadine, or anticholinergic drugs is permitted if use
was initiated greater than (>) 90 days before signing of the informed consent, the
dosage has remained stable for a minimum of 4 weeks before signing of the informed
consent, and the dosage will remain stable for the duration of the trial (ie, no
change in the COMT, MAO-B inhibitor, or amantadine dose is permitted during the
trial).

Exclusion Criteria:

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

– Participants with a history of nonresponse or insufficient response to L-Dopa at
therapeutic dosages

– Participants who have had previous surgical intervention (eg, deep brain stimulation)
for PD or for whom such a procedure is planned or anticipated during the trial period

– Participants with an acute or chronic, clinically significant medical or psychiatric
condition, cognitive impairment, or laboratory abnormality that might increase the
risk associated with trial participation or administration of trial treatment or
interfere with the interpretation of the trial results or that, in the judgment of the
investigator, would make the Participant inappropriate for entry into this trial.-
Medical conditions that are minor or well controlled may be considered acceptable if
the condition does not expose the Participant to an undue risk of a significant AE or
interfere with the assessments of safety or efficacy during the course of the trial.
Participants with symptoms of anxiety or depression that are not debilitating and that
are stable or adequately controlled with non-prohibited medication are considered
acceptable. The medical monitor should be contacted in any instance where the
investigator is uncertain regarding the stability of a Participant’s medical
conditions(s) and the potential impact of the condition(s) on trial participation

– Participants with a history or current diagnosis of a clinically significant impulse
control disorder (Disruptive, Impulse Control, and Conduct Disorder per DSM-5)
(American Psychiatric Association, 2013)

– 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

– Participants who answer “yes” on the Columbia-Suicide Severity Rating Scale (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 who have a positive result for human immunodeficiency virus (HIV)
antibodies, hepatitis B surface antigen (HbsAg), or hepatitis C virus (HCV) antibodies
at screening

– Participants with a history of malignancy other than:

– Non-metastatic basal or squamous cell carcinoma of the skin or carcinoma in situ that
was surgically removed in total >1 year before signing the ICF and had not recurred

– Another type of malignancy that had been in remission for ≥5 years before signing the
ICF and had not recurred

– Participants with a history of myocardial infarction with residual atrial, nodal, or
ventricular arrhythmias that are not controlled with medical and/or surgical
intervention; second- or third-degree atrioventricular block; sick sinus syndrome;
severe or unstable angina; or congestive heart failure within the last 12 months. A
recent (less than or equal to [<=12] months) history of myocardial infarction with secondary arrhythmias is exclusionary regardless of the therapeutic control - Participants with a history of neuroleptic malignant syndrome - Female Participants who are breastfeeding and/or who have a positive pregnancy test result prior to receiving IMP - Participants who are currently receiving moderate or strong cytochrome P450 (CYP) 3A4 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-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 who are using any prohibited medication during the trial within at least 4 weeks or 5 half-lives (whichever is greater) prior to signing the ICF - Participants with a Montreal Cognitive Assessment (MoCA) score <26 - Participants with a sitting blood pressure greater than or equal to (>=) 160
millimeter of Hg (mmHg) (systolic) or >=100 mmHg (diastolic) on a single measurement.
If abnormal, up to 2 repeat measurements are permitted after at least 5 minutes of
rest

– Participants with clinically significant orthostatic hypotension (eg, syncope)

– Participants with a 12-lead ECG demonstrating a QTcF interval >450 msec (average of 3
ECGs obtained at the Screening Visit)

– Participants with moderate or severe renal impairment (creatinine clearance as
estimated by Cockcroft-Gault formula <30 milliliter per minute [mL/min] or on dialysis) - Participants with any of the following abnormalities in clinical laboratory tests at the Screening Visit, as assessed by the central laboratory and confirmed by a single repeat measurement, if deemed necessary: - AST or ALT >=3 × Upper Limit Normal (ULN)

– Total bilirubin >=1.5 × ULN. Participants with a history of Gilbert’s syndrome may be
eligible provided they have a value

Locations

• Fountain Valley, California, Fountain Valley, California, United States, 92708
• Frenso, California, Fresno, California, United States, 93710
• Long beach, California, Long Beach, California, United States, 90806
• Pasadena, California, Pasadena, California, United States, 91105
• Reseda, California, Reseda, California, United States, 91335