To Evaluate the Efficacy of CVN424 in Parkinson's Disease Participants With Motor Complications

The assessment of the ON time without troublesome dyskinesia will be based on diaries completed at home for three consecutive days during the 7-day period before a scheduled in-person visit.

The MDS-UPDRS is a comprehensive 50-question assessment of both motor and non-motor symptoms associated with PD. It features sections that require independent completion by people with PD and their caregivers, and sections to be completed by the same clinician throughout the study. Part II assess motor experiences of daily living, motor aspects of experiences of daily living. This part has 13 items. It is a self-administered questionnaire completed by the participant, which can be reviewed by the Investigator to ensure all responses are completed.

The CGI-S is a 7-point scale, with the severity of illness scale using a range of responses from 1 (normal/not at all ill) to 7 (amongst the most severely ill participants). This requires the clinician to rate the severity of the participant's illness at the time of assessment, relative to the clinician's past experience with participants who have the same diagnosis. Higher scores indicate worser the illness.

The PGI-S is a participant-completed assessment rating PD severity on a scale of 1 to 5 with 1 being none and 5 being very severe. Higher scores indicate worser the illness.

The MDS-UPDRS is a comprehensive 50-question assessment of both motor and non-motor symptoms associated with PD. It features sections that require independent completion by people with PD and their caregivers, and sections to be completed by the same clinician throughout the study. Part III consists of 33 scores based on 18 items, and each question is anchored with five response scale from 0 (normal) to 4(severe). A 0 means there is no disability, and the higher the score, the more the disability is reflected. The maximum score for Part III is 132. The total score is the sum of the numerical response values of the items. It is completed by a rater based on findings from the motor examination.

The ESS is a participant self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0 to 3: would never doze, slight chance of dozing, moderate chance of dozing, and high chance of dozing), their usual chances of dozing off or falling asleep while engaged in eight different activities, such as sitting and reading, watching television, sitting in a public place, etc. Most people engage in those activities at least occasionally, although not necessarily every day. The ESS score (the sum of 8 item scores) can range from 0 to 24. The higher the ESS score, the higher that person's average sleep propensity in daily life, or their "daytime sleepiness". The questionnaire takes no more than 2 or 3 minutes to answer.

The assessment of the ON time with no dyskinesia will be based on diaries completed at home for three consecutive days during the 7-day period before a scheduled in-person visit.

The MDS-UPDRS is a comprehensive 50-question assessment of both motor and non-motor symptoms associated with PD. It features sections that require independent completion by people with PD and their caregivers, and sections to be completed by the same clinician throughout the study. Part I assess non-motor experiences of daily living, non-motor aspects of experiences of daily living (6 items assessed by interview and 7 items by self-assessment). It has 13 items and is further grouped into two parts: Part IA has items associated with behaviors that are assessed and completed by the rater based on information provided by the participant and caregiver. Part IB is self-administered and completed by the participant with or without assistance or input from the caregiver, but independently of the rater. Responses to both IA and IB can be reviewed by the rater to ensure information accuracy and/or provide additional information or clarification of the test items, if necessary.

The PDQ is a 39-item self-report questionnaire that assesses eight PD-specific health related quality of life functions over the previous month. Assesses how often participants with PD experience difficulties across 8 dimensions of daily living including relationships, social situations and communication. The 39-item questionnaire offers a participant reported measure of health status and quality of life and is the most frequently used disease-specific health status measure. It also assesses the impact of PD on specific dimensions of functioning and wellbeing.

The SAS instrument is used to identify apathy in participants with PD. The scale comprises 14 questions in which the respondent self-rates on a 4-point scale, ranging from "Not at all", "Slightly", "Some", and "A Lot". Ratings are a score from 3 to 0 for questions 1-8, and from 0 to 3 for questions 9-14, producing a total score out of 42. A score above 14 is considered the more severe level of apathy.

Cogstate Digital Cognitive Testing Battery are computerized cognitive assessments of attention, executive function, verbal learning, and memory. It uses standardized scores to assess participant's cognitive function. These scores are transformed into a scale where the average performance of the general population is set at 100, with a standard deviation of 15. This means that a score of 100 represents average cognitive function, while scores above or below indicate better or poorer performance, respectively, compared to the average.

The Schwab and England Activities of Daily Living Scale is a commonly used tool to measure daily function for Parkinson's disease. The S \& E Scale rates a PD participant's function on a scale from 0 indicating worst possible function to 100 indicating no impairment.

The QUIP-RS has 4 questions (common thoughts, urges/desires, self-control, faciliatory behaviors associated with impulse control disorders [ICDs]), each applied to 4 main impulse control disorders (gambling, buying, eating, and sexual behavior) and 3 related impulsivity disorders (medication use, punding, and hobbyism). Scores range from 0-4 for each question to gauge the frequency of behaviors over the preceding 4 weeks (or any defined 4-week period). Total scores range from 0 to 112.