Unilateral and Staged Bilateral Pallidothalamic Tractotomy Using Exablate MRgFUS in Advanced Parkinson's Disease. (FREEDOM)

August 20, 2026 updated by: InSightec

An MR Guided Focused Ultrasound (MRgFUS) Randomized Trial Using the Exablate Neuro System to Assess the Effectiveness and Safety Outcomes of Unilateral and Staged Bilateral Ablation in the Subthalamic Region Involving the Pallidothalamic Tract (PTT) in Advanced Parkinson's Disease (PD) With Motor Complications.

This study is a randomized clinical trial evaluating a focused ultrasound treatment for people with advanced Parkinson's disease (PD) who have disabling motor complications and symptoms.

The study uses the Exablate Neuro System, which delivers MR-guided Focused Ultrasound (MRgFUS). This technology focuses ultrasound energy on a specific brain target and generates heat to create a small lesion (ablation) without making a surgical incision.

The target in this study is the Pallidothalamic Tract (PTT), a pathway involved in the abnormal brain circuits that contribute to Parkinson's symptoms and complications.

This study is evaluating whether treating one side of the brain or treating both sides (in separate procedures) provides better outcomes for people with advanced Parkinson's disease who have motor complications and symptoms.

The main outcome measure is the change in the MDS-UPDRS Part III Upper/Lower Extremity (ULE) score at 3 months after first and second side treatment, compared with the respective control groups.

MDS-UPDRS Part III is a standard clinical scale used to assess Parkinson's motor symptoms. ULE score focuses on motor function in the arms and legs. Assessments are performed in the OFF-medication state, meaning Parkinson's medications are temporarily withheld so that the treatment effect can be measured more accurately.

In addition improvement in motor complications will be assessed with MDS-UPDRS Part IV and Patient diaries.

Study Overview

Detailed Description

A Post Approval Study (US) / Pre Market Extension Study (Outside US), international prospective, multi-center, assessor-blinded, two-stage (2:1) randomized controlled trial evaluating successive Exablate treatment (first and second side) versus BMT (Best Medical Treatment).

In individuals eligible for the staged, bilateral Exablate PTT procedure, building on evidence from the predicate pivotal staged bilateral study that led to PMA approval in the United States, this trial aims to evaluate the successive treatment of 1st and 2nd side Exablate PTT ablation using a two-stage randomized controlled design. In Stage 1, patients will be randomized to receive either 1st side PTT procedure or best medical treatment (BMT). Patients who initially randomized to receive BMT will cross over to receive 1st side PTT procedure after 3 months (if they still qualify for the treatment). All patients will continue to be followed through a 6-month period post 1st side treatment. All eligible patients who reach Stage 2 will be re-randomized to undergo 2nd side PTT procedure or continue with BMT. Patients randomized to receive BMT in stage 2 will cross over to receive 2nd side PTT procedure after 3 months (if they still qualify for the treatment). All patients will continue to be followed through a 12-month period post 2nd side treatment. This design enables evaluation between staged-bilateral treatment, unilateral treatment alone, and standard of care (SOC)/BMT medical therapy. This study will generate real-world comparative data to better inform decision-makers about the generalizability in subthalamic region ablations involving the PTT. Outcomes will be assessed using relevant lateralized Parkinson-specific clinical scales, measures of functional impairment, disease-specific quality of life, adverse events, and patient-reported perceptions of overall treatment effectiveness.

Study Type

Interventional

Enrollment (Estimated)

120

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

      • Seoul, South Korea
        • Korea University Anam Hospital
        • Contact:
        • Principal Investigator:
          • Kyoungwon Baik

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Men or women, age 30 years and older
  2. Subject is able and willing to give informed consent and able to attend all study visits
  3. Subject with a diagnosis of idiopathic PD by UK Brain Bank Criteria as confirmed by a movement disorder neurologist at the site.
  4. Subject is interested in receiving bilateral treatment if they qualify.
  5. Subject is Levodopa responsive as defined by at least a 30% reduction in MDS-UPDRS motor subscale in the ON vs OFF medication state.
  6. Subject has MDS-UPDRS Part III OFF ULE score of ≥ 15 on each side in the meds OFF condition.
  7. Subject experiencing motor complications of PD on optimum medical treatment characterized by dyskinesia (MDS-UPDRS item 4.2 score of ≥ 2) OR Motor fluctuations (MDS-UPDRS item 4.4 score of ≥ 2)
  8. Subject is on a stable dose of all PD medications for 30 days prior to screening visit PD assessments as determined by medical records
  9. Subject is able to communicate sensations during the Exablate procedure.
  10. Subject's pallidothalamic region can be targeted by the Exablate device.

Exclusion Criteria:

  1. Subject with severe premorbid risks as specified in the MDS-UPDRS Part II subsection motor aspects of experiences of daily living scores:

    1. 3 or 4 on question 2.1 (speech) OR
    2. 3 or 4 on question 2.3 (chewing and swallowing) OR
    3. 4 on question 2.2 (saliva and drooling).
  2. Subject where there is suspicion that Parkinsonian symptoms are a side effect from neuroleptic medications.
  3. Subject has an MMSE score < 24.
  4. Subject has other central neurodegenerative disease suspected on neurological examination. These include: multisystem atrophy, progressive supranuclear palsy, corticobasal syndrome, dementia with Lewy bodies, and Alzheimer's disease.
  5. Subject with unstable psychiatric disease, uncontrolled depressive symptoms, psychosis, delusions, hallucinations, or suicidal ideation.
  6. Female subject who is pregnant.
  7. Female subject of childbearing potential not willing to use contraceptives throughout the duration of the study (~ 24 months)
  8. Subject exhibiting any behavior(s) consistent with ethanol or substance abuse.
  9. Subject with unstable cardiac status or severe hypertension.
  10. Subject with history of abnormal bleeding, hemorrhage, or coagulopathy.
  11. Subject with cerebrovascular disease.
  12. Subject is receiving anticoagulant (e.g., warfarin) or antiplatelet (e.g., aspirin) therapy within one week of focused ultrasound procedure or drugs known to increase risk or hemorrhage (e.g., Avastin) within one month of focused ultrasound procedure.
  13. Subject with advanced kidney disease or on dialysis.
  14. Subject with a history of seizures within the past year.
  15. Subject with a brain tumor.
  16. Subject with life-threatening systemic disease (e.g. HIV, liver failure, blood dyscrasias, etc.).
  17. Subject with any illness that in the investigator's opinion precludes participation in this study.
  18. Subject with standard contraindications for MR imaging such as implanted metallic devices.
  19. Subject who had prior deep brain stimulation of the basal ganglia or thalamus.
  20. Subject who is unable to tolerate the required prolonged stationary supine position during treatment.
  21. Subject who has an Overall Skull Density Ratio of less than 0.40 as calculated from the screening CT (if this is the only exclusion, subject can participate in the study as part of the reference group).
  22. Subject who is participating in another clinical investigation with an active treatment arm
  23. Subject who is unable to communicate with the investigator and staff.
  24. Subject who is in a nursing home in the last 30 days.

    Additional Exclusion Criteria for Staged Bilateral PTT procedure

  25. Clinically significant neurological event of dysphagia, abnormal speech function, or gait abnormalities that are moderate to severe following first procedure.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Sequential Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Active Group 1_Unilateral Exablate Pallidothalamic Tractotomy
Subjects will undergo the 1st side Exablate procedure (< 30 days after randomization) and will be followed for 6 months. At their Month 6 visit, subjects will have their re-baseline assessment and undergo staged randomization for the 2nd side treatment.
1st side Exablate MRgFUS Pallidothalamic Tractotomy for Parkinson's Disease
Active Comparator: Control Group 1_Best Medical Treatment (BMT)
Subjects will have their standard of care (SOC) treatment adjusted to best effect (BMT), and will be followed for 3 months. After their Month 3 visit, subjects will cross over to receive the 1st side treatment and be followed for 6 months. At their Month 6 visit, subjects will have their Treatment 2 re-baseline assessment and undergo staged randomization for the 2nd side treatment.
Subjects will be managed according to conventional therapeutic guidelines (i.e., best medical treatment) for Parkinson's Disease
Experimental: Active Group 2_Staged Bilateral Exablate Pallidothalamic Tractotomy
Subjects will undergo the 2nd side Exablate procedure (< 30 days after re-baseline assessment, and will be followed for 12 months.
1st side Exablate MRgFUS Pallidothalamic Tractotomy for Parkinson's Disease
2nd side staged Exablate MRgFUS Pallidothalamic Tractotomy for Parkinson's Disease
Active Comparator: Control Group 2_BMT after Unilateral Exablate Pallidothalamic Tractotomy
Subjects will continue with their SOC BMT and will be followed for 3 months. After their Month 3 visit, subjects will cross over to receive the 2nd side treatment and be followed for 12 months.
1st side Exablate MRgFUS Pallidothalamic Tractotomy for Parkinson's Disease
Subjects will be managed according to conventional therapeutic guidelines (i.e., best medical treatment) for Parkinson's Disease
Active Comparator: Reference Group_BMT with low SDR
Subjects will be offered the option to receive best medical treatment and will be followed to capture natural disease progression at approximately the same time schedule as patients in the randomized groups (~ every 3 - 6 months for up to 24 months).
Subjects will be managed according to conventional therapeutic guidelines (i.e., best medical treatment) for Parkinson's Disease

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
MDS-UPRDS Part III ULE score in the OFF-medication (unilateral treatment)
Time Frame: 3 Months

Between-group difference (Active Group 1 vs. Control Group 1) in the treatment effect (point change) in the MDS-UPRDS Part III ULE score in the OFF-medication state from Baseline to 3 month.

This assessment will be performed by a Movement Disorders neurologist blinded to patient study group allocation.

3 Months
MDS-UPRDS Part III ULE score in the OFF-medication (bilateral treatment)
Time Frame: 3 Months

Between-group difference (Active Group 2 vs. Control Group 2) in the treatment effect (point change) in the MDS-UPRDS Part III ULE score in the OFF-medication state from Baseline to 3 month.

This assessment will be performed by a Movement Disorders neurologist blinded to patient study group allocation.

3 Months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
MDS-UPDRS III Total score in the OFF-medication state
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months
MDS-UPDRS Part III OFF ULE score
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months
MDS-UPDRS Part III ON Total score
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months
MDS-UPDRS Part IV Total score
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months
Number of hours per day in ON time without troublesome dyskinesia- as measured by patient diaries (unilateral)
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months
Number of hours per day in the OFF time as measured by patient diaries (unilateral)
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months
Number of hours per day with troublesome dyskinesia (unilateral)
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months
Quality of Life as measured by PDQ-39 (unilateral)
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months
Levodopa equivalent dose change usage (milligrams) (unilateral)
Time Frame: 1 Month, 3 Months, 6 Months, 12 Months

Between-group comparison (Active Group 1 vs Control Group 1) of the treatment effect at Month 3 following Treatment 1 (unilateral) and within-group comparison (Active Group 1) of the treatment effect at all study visits (Month 1, 3 and 6) following Treatment 1 compared to baseline.

Between-group comparison (Active Group 2 vs Control Group 2) of the treatment effect at Month 3 following Treatment 2 (staged bilateral) and within-group comparison (Active Group 2) of the treatment effect at all study visits (Month 1, 3, 6 and 12) following Treatment 2 compared to baseline.

1 Month, 3 Months, 6 Months, 12 Months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Joohi Jimenez-shahed, MD, Mount Sinai, Clinical Neurosciences Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 1, 2026

Primary Completion (Estimated)

December 1, 2029

Study Completion (Estimated)

June 1, 2031

Study Registration Dates

First Submitted

August 10, 2026

First Submitted That Met QC Criteria

August 10, 2026

First Posted (Actual)

August 14, 2026

Study Record Updates

Last Update Posted (Actual)

August 24, 2026

Last Update Submitted That Met QC Criteria

August 20, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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