A Study to Assess the PK and Pharmacodynamics of IPX203 in Subjects With Advanced Parkinson's Disease

IPX203 is an investigational product containing CD‑LD.

IPX203-B16-01 Study Design:

A randomized, open-label, rater-blinded, multicenter, 2-treatment, 2‑period, multiple-dose
crossover study.

Approximately 30 qualified IR CD-LD-experienced advanced PD subjects will be randomized.

The study duration will be approximately 8 weeks, including the screening period.

Eligibility will be determined at screening and Visit 1 of the study.

Inclusion Criteria:

- Diagnosed with idiopathic PD at age ≥ 40 years who are being chronically treated with
stable regimens of CD-LD but experiencing motor complications.

- Hoehn and Yahr Stages 2, 3, or 4

- Montreal Cognitive Assessment (MoCA) score ≥ 24 at Screening Visit in "on" state.

- For the 4 weeks prior to the Screening, the subject experiences daily "wearing-off"
episodes with periods of bradykinesia and rigidity and experiences an "off" state upon
awakening on most mornings by history.

- Responsive to CD‑LD therapy and currently being treated on a stable regimen with CD‑LD
for at least 4 weeks prior to Visit 1

- Typically experiences an "on" response with the first dose of IR CD‑LD of the day (by
subject history).

- By history, efficacy of the first morning dose of IR CD-LD lasts less than 4 hours

Exclusion Criteria:

- History of medical conditions or of a prior surgical procedure that would interfere
with LD absorption, such as gastrectomy or proximal small-bowel resection.

- Liver enzyme values ≥ 2.5 x the upper limit of normal; or history of severe hepatic
impairment.

- History of drug or alcohol abuse within the 12 months prior to Screening.

- Received within 4 weeks of Visit 1 or planning to take during participation in the
clinical study: any doses of a controlled-release (CR) LD apart from a single daily
bedtime dose or any doses of Rytary, additional CD (eg, Lodosyn) or benserazide (eg,
Serazide), or catechol-O-methyl transferase inhibitors (entacapone or tolcapone) or
medications containing these inhibitors (Stalevo). Received within 4 weeks of Visit 1
or planning to take during participation in the clinical study: nonselective monoamine
oxidase (MAO) inhibitors, apomorphine, or dopaminergic blocking agents including
antiemetics.

- History of psychosis within the past 10 years.

- Treatment with any dopamine antagonist antipsychotics for the purposes of psychosis or
bipolar disorder within the last 2 years.

- Based on clinical assessment, subject does not adequately comprehend the terminology
needed to complete the PD Diary.