The purpose of this study is to evaluate the effect of IPX203 (Crexont®) - the newest extended-release levodopa formulation - on the duration and quality of good on time, using a wearable device to monitor symptoms. 'Good on time' refers to a period (minutes to hours) when a patient experiences optimal symptom control due to effective medication and has better overall functioning without troublesome dyskinesias. The change in the duration and quality of on-time will be measured by a wearable device placed on your wrist called KinesiaU.

This research is being done because a new, longer-duration formulation of levodopa named IPX203 (brand name: Crexont®) has been recently approved by the FDA. The pivotal study on this drug demonstrated that IPX203 significantly increased the daily good on-time compared to immediate release carbidopa-levodopa (IR CD-LD), where good on-time is the time when the Parkinson's symptoms are improved without troublesome dyskinesias. In that study, the participants were taking IPX203 a mean of 3 times per day which still left a mean of 4.18 hours of off-time per day (when symptoms returned). These data were based on diaries filled out by the participants.

The aim of the study is to expand the current knowledge on IPX203, analyzing the changes in good on-time after careful and tailored adjustments, as in the real-world setting. This will be done with the assistance of a wearable device to obtain objective data. Additional variables such as changes in the tremor scores, conversion from other drugs such as Rytary and COMT inhibitors, and the difference between starting and final IPX203 doses will be evaluated.

Inclusion Criteria:

• - Participant is 40 years or older
• Diagnosed with idiopathic Parkinson's disease and is deemed to be levodopa responsive
• Baseline MDS-UPDRS score in OFF-state is > 20
• Patient is being treated with a stable regimen of CD-LD for at least four weeks
• The minimum most frequent levodopa dosing is 100 mg if using IR CD-LD and 195mg if using Rytary; maximum levodopa dosing per day is 1200 mg if using IR CD-LD, 1000 mg if associated with a COMT inhibitor, and 2400 mg if using Rytary
• Participant can be on stable doses of any levodopa adjunctive medications and/or psychotropic medications for at least 30 days
• Participant experiences off time estimated at 2 hours or more per day; participant can comply with the wearable kinematic device.

Exclusion Criteria:

• - Participants with severe dyskinesia as defined by a score of 4 on Question 4.1 (time spent with dyskinesia) of UPDRS IV
• Currently on device-aided therapies for advanced PD
• Using controlled-release CD-LD apart from a single daily bedtime dose
• Using "on demand" therapy unless willing to stop it during the study period
• Have a diagnosis hypothesis of dopamine dysregulation syndrome or evidence of significant levodopa-related complications including orthostatic hypotension or psychosis
• History of dementia or MOCA score lower than 23
• Significant medical history might interfere significantly with study participation
• Being enrolled in other clinical trials involving active medication interventions.