NCT07432958 · Appello Pharmaceuticals, Inc.
A Study to Evaluate the Effectiveness of Two Doses of AP-472 as Adjunctive Therapy to Levodopa in Parkinson's Disease (PD) Participants With Motor Fluctuations
What this study is about
This is a Phase 2 study in people with Parkinson's disease who experience motor fluctuations while taking levodopa. The study will evaluate how effective two different doses of the study drug AP-472 are when added to levodopa treatment, compared with a placebo. The study will last about 12 weeks. Participants will be randomly assigned to receive one of the two doses of AP-472 or a placebo.
View original scientific description
This is a Phase 2 study in people with Parkinson's disease who experience motor fluctuations while taking levodopa. The study will evaluate how effective two different doses of the study drug AP-472 are when added to levodopa treatment, compared with a placebo. The study will last about 12 weeks. Participants will be randomly assigned to receive one of the two doses of AP-472 or a placebo. Neither the participants nor the study staff will know which treatment is given. The study includes a screening period, a 4-week period during which Parkinson's medications must remain stable, and an 8-week treatment period. During the treatment period, limited adjustments to levodopa are allowed if needed.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants must meet all of the following criteria to take part in the study:
- Be a man or woman between 30 and 80 years of age at the time of screening.
- Have a diagnosis of Parkinson's disease, confirmed using standard medical criteria, including slowness of movement and symptoms that affect one side of the body more than the other.
- Have mild to moderate Parkinson's disease, defined as stage 3 or lower on the Hoehn and Yahr scale when medications are working ("ON" state).
- Experience an average of at least 3 hours of OFF time per day, based on home symptom diaries, with at least 2.5 hours of OFF time each day during the baseline period.
- Have a Montreal Cognitive Assessment (MoCA) score of 24 or higher at screening.
- Be able to walk independently, with or without the use of a walking aid.
- Be able to swallow oral medication.
- Have been on a stable Parkinson's medication regimen for at least 4 weeks before screening. Medications known as MAO-B inhibitors must have been stable for at least 12 weeks.
- Be taking levodopa at least four times daily (immediate- or controlled-release formulations) or three times daily (extended-release formulations such as Rytary or Crexont). Key
Exclusion criteria
- Participants cannot take part in the study if any of the following apply:
- Have a form of parkinsonism that is not typical Parkinson's disease, such as secondary or atypical parkinsonism.
- Have previously received, or plan to receive during the study, advanced Parkinson's therapies such as continuous levodopa or dopamine delivery systems, or Parkinson's disease-related brain surgery.
- Have dyskinesias (involuntary movements) that are severe enough, in the study doctor's opinion, to interfere with participation.
- Have a history of only certain types of dyskinesias (such as OFF-state, diphasic, myoclonic, or dystonic dyskinesias) without typical peak-dose dyskinesias.
- Are currently taking medications that block dopamine, except for low-dose quetiapine (up to 50 mg per day) used for insomnia.
- Routinely use on-demand "rescue" Parkinson's medications more than three times per week.
Where
- Little Rock, Arkansas
- Los Alamitos, California
- Los Angeles, California
- Oceanside, California
- Palo Alto, California
- Englewood, Colorado
- Miami, Florida
- Orlando, Florida
- Tampa, Florida
- Augusta, Georgia
- Kansas City, Kansas
- Lexington, Kentucky
And 12 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 6, 2026 · Source of record for eligibility and locations