---
title: Cell implant reduces off time
nct_id: NCT06687837
phase: PHASE1
status: RECRUITING
sponsor: Jeffrey S. Schweitzer, MD, PhD
study_type: INTERVENTIONAL
canonical_url: "https://parkinsonspathways.com/trial/NCT06687837"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT06687837"
last_fetched: "2026-05-10T14:02:54.316Z"
source: "Parkinson's Pathways (curated)"
---
# Cell implant reduces off time

**Goal (in five words):** Cell implant reduces off time

**Official Title:** Phase I Trial of Autologous Induced Pluripotent Stem Cell-derived Dopaminergic Progenitor Cell Transplantation for Parkinson's Disease

**Trial ID:** [NCT06687837](https://clinicaltrials.gov/study/NCT06687837)

## Key Facts

- **Phase:** PHASE1
- **Status:** RECRUITING
- **Study Type:** INTERVENTIONAL
- **Sponsor:** Jeffrey S. Schweitzer, MD, PhD
- **Target Enrollment:** 8 participants
- **Start Date:** 2025-04-29
- **Completion Date:** 2027-12
- **Conditions:** Parkinson Disease
- **Interventions:** autologous dopaminergic cell implantation
- **Intervention Types:** BIOLOGICAL

## Summary For Families

The goal is to test whether implanting a person’s own lab-grown dopaminergic progenitor cells into the putamen is safe and feasible, with the hope these cells can replace lost dopamine-producing neurons and eventually improve motor symptoms. The team reprograms a patient’s cells into induced pluripotent stem cells, turns them into dopaminergic progenitors, and surgically implants them so they can mature and release dopamine long-term; because the grafts are autologous there is less need for chronic immunosuppression, and participants must stay on a stable levodopa regimen and defer device-based or infusion therapies until initial outcomes are assessed. They are looking for people aged 45 to 80 who have had Parkinson’s for at least five years, are Hoehn and Yahr stage 3,4 off medication, show clear levodopa responsiveness on at least 300 mg/day, and experience at least three hours of off time per day. This is a Phase 1 safety study enrolling about eight people, so the main focus is careful monitoring for surgical and graft-related risks rather than proving benefit.

## Eligibility

- **Minimum age:** 45 Years
- **Maximum age:** 80 Years
- **Sex:** ALL

### Full Criteria

```
Inclusion Criteria:

* Diagnosis of Parkinson's Disease consistent with the Movement Disorders Society 2015 Parkinson's diagnostic criteria.
* Age 45 - 80 years
* English proficiency sufficient to understand the consent form and participate in a discussion of risks and benefits
* At least 5 years since Parkinson's disease motor symptom onset
* Modified Hoehn and Yahr stage 3-4 in "off"-medication state
* Motor symptoms responsive to levodopa and/or dopamine agonist, defined as taking at least 300 mg/day of levodopa and exhibiting improvement between "off" and "on" MDS-UPDRS of at least 30%
* At least 3 hours of cumulative "off" time per day
* Stable regimen of Parkinson's medications, including levodopa and dopamine agonists, for at least 4 weeks prior to screening.
* Acceptable surgical laboratory values including:

  1. Platelets \> 100×109/L (transfusion independent)
  2. Prothrombin time / partial thromboplastin time in normal range and international normalized ratio ≤ 1.3
  3. Aspartate aminotransferase and alanine aminotransferase \< 2.5x the upper limit of normal
  4. Serum creatinine ≤ 1.5mg/dL
  5. White blood cell count \< 12×109/L.
  6. Estimated glomerular filtration rate ≥ 30 mL/min/1.73m2
* Subject agrees to defer elective neurological surgery, including deep brain stimulation or lesional procedure for PD, invasive treatments, including levodopa or apomorphine infusion, or pump- pump-administered levodopa intestinal gel, until after the study's primary outcome is completed.
* Findings on baseline 18F-DOPA PET imaging consistent with dopaminergic denervation of the putamen
* Subject is willing and able to comply with all study visits and procedures in the opinion of the Investigator.

Exclusion Criteria:

* Subjects unable to give consent due to dementia or psychosis.
* Montreal Cognitive Assessment (MoCA) score \< 26
* Subjects with a first-degree relative with Parkinson's disease or with a known genetic mutation predisposing to the development of Parkinson's disease (i.e. this initial study is confined to the more common "sporadic" vs a "genetic" form of the disease).
* Atypical Parkinsonism (Parkinson's-Plus syndrome, secondary parkinsonism)
* Moderate or severe levodopa-induced dyskinesias in any body segment (such patients were found to be more prone to graft-induced dyskinesias in the fetal tissue studies that are proof of priniciple for this therapy)
* Neurologic history or imaging demonstrating brain pathology not directly related to Parkinson's disease that is likely to interfere with study compliance or assessment of Parkinson's related motor disability.
* History of stroke or transient ischemic attack
* History of subarachnoid hemorrhage
* Presence or history of psychosis within 12 months of screening
* Suicidal ideation associated with intent or plan in the past 12 months (an answer of "yes" to C-SSRS questions 4 or 5) or with a previous history of suicide attempts in the past 5 years.
* History of intracranial surgery including deep brain stimulation, focused ultrasound, stereotactic or radiosurgical lesion therapy
* History of malignancy within 5 years. Exceptions will be made for treated cutaneous squamous cell or basal cell carcinoma without evidence of metastasis.
* Use of anticoagulation / antiplatelet agents that cannot be stopped for one week in advance of and two days following surgery without significant risk to the subject
* Use of chronic immunosuppressive therapy including chronic steroids
* Contraindication to MRI or MRI contrast agents
* Pregnant or nursing women
* Subjects with active cardiovascular and cerebrovascular disease within 6 months prior to signing the informed consent form.
* History of severe heart failure (congestive heart failure of New York Heart Association Class II or above or left ventricular ejection fraction \< 35% by any examination method), unstable angina pectoris and myocardial infarction/
* Severe arrhythmia
* History of cardiovascular surgery (cardiac, vascular stent surgery, angioplasty)
* Patients with major vascular diseases (aortic aneurysm, aortic dissecting aneurysm, internal carotid artery stenosis)
* Hypertensive patients with poorly controlled blood pressure (defined as blood pressure consistently above 160/100 mmHg despite treatment with antihypertensive drugs) and patients with severe postural hypotension
* Diabetic patients with poorly controlled blood glucose (glycosylated hemoglobin \> 9.0%, or fasting plasma glucose (FPG) ≥ 11.1 mmol/L);
* Subjects with alcohol or drug addiction
```

## Locations (1)

- Massachusetts General Hospital, Boston, Massachusetts, United States _(42.3584, -71.0598)_
  - Jeffrey S Schweitzer, MD, PhD — (CONTACT) — 617-726-1799 — jschweitzer1@mgh.harvard.edu
  - Dolores Smith — (CONTACT) — 617-726-1799 — vprathivadi@mgh.harvard.edu

## Central Contacts

- Jeffrey S Schweitzer, MD, PhD — (CONTACT) — 6177261799 — JSCHWEITZER1@mgh.harvard.edu

---

*Canonical: https://parkinsonspathways.com/trial/NCT06687837*  
*HTML version: https://parkinsonspathways.com/trial/NCT06687837*  
*Source data: https://clinicaltrials.gov/study/NCT06687837*