Evaluating KDT-3594 for Parkinson's Disease

A Late Phase II Clinical Trial of KDT-3594 in Patients With Advanced Parkinson's Disease With Levodopa

PHASE2 · Kissei Pharmaceutical Co., Ltd. · NCT06722729

This study is testing a new medication called KDT-3594 to see if it can help people with advanced Parkinson's Disease who are already taking levodopa feel better.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment150 (estimated)
Ages18 Years to 80 Years
SexAll
SponsorKissei Pharmaceutical Co., Ltd. (industry)
Locations1 site (Multiple Locations)
Trial IDNCT06722729 on ClinicalTrials.gov

What this trial studies

This late phase II clinical trial is designed to assess the efficacy, safety, and pharmacokinetics of KDT-3594 in patients with advanced Parkinson's Disease who are currently on levodopa treatment. The trial will be multicenter, randomized, double-blind, and placebo-controlled, involving escalating doses of KDT-3594 administered once daily for 17 weeks. Participants will be monitored for improvements in troublesome symptoms associated with their condition.

Who should consider this trial

Good fit: Ideal candidates are patients diagnosed with Parkinson's Disease who are currently treated with levodopa and experience troublesome symptoms such as wearing-off or ON-/OFF-phenomena.

Not a fit: Patients with parkinsonism other than Parkinson's Disease or those who have undergone neurosurgical therapy for PD may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve the management of symptoms in patients with advanced Parkinson's Disease.

How similar studies have performed: Other studies have shown promise in similar approaches, but the specific efficacy of KDT-3594 remains to be established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients diagnosed with PD according to the Parkinson's disease society brain bank clinical diagnostic criteria of the UK Parkinson's Disease Society
* Patients who are being treated with levodopa or levodopa combination drugs and have any of the following troublesome symptoms or conditions:
* Patients with wearing-off phenomenon
* Patients with ON-/OFF-phenomenon
* Patients with no-on/delayed on phenomenon
* Patients with inadequate response to levodopa

Exclusion Criteria:

* Patients suspected of having parkinsonism other than PD based on medical history, physical findings, laboratory test values, dopamine transporter-single photon emission computed tomography (DAT-SPECT), etc.
* Patients who have undergone neurosurgical therapy for PD (e.g., stereotactic thalamotomy and pallidotomy and deep brain stimulation) or who are scheduled to undergo surgical therapy during the trial period
* Patients complicated with overt dementia or a Mini-Mental State Examination (MMSE) score of \< 24 at the start of the screening period

Where this trial is running

Multiple Locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Parkinson Disease

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.