XS411 for early-onset Parkinson's disease

A Phase I/II Clinical Study to Evaluate the Safety, Tolerability, and Efficacy of Human Allogeneic Induced Pluripotent Stem Cell-derived Dopaminergic Neural Progenitor Cell Injection in the Treatment of Early-onset Parkinson's Disease

Phase1; Phase2 Interventional XellSmart Bio-Pharmaceutical (Suzhou) Co., Ltd. · NCT07166757

This study will try a single injection of XS411 (iPSC-derived dopaminergic neural progenitor cells) to see if it is safe and helps people with early-onset Parkinson's disease whose motor symptoms are not controlled by medication.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment90 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorXellSmart Bio-Pharmaceutical (Suzhou) Co., Ltd. Industry-sponsored
Locations1 site (Shanghai, Shanghai Municipality)
Trial IDNCT07166757 on ClinicalTrials.gov

What this trial studies

Phase I uses an open-label, single-arm 3+3 dose-escalation design enrolling 6–12 patients to test two dose cohorts (9×10^6 and 1.8×10^7 cells per patient) with each participant receiving a single intracerebral injection and at least 28 days of safety observation to determine the RP2D. Phase II is planned as a randomized, double-blind, sham-controlled study in patients meeting similar early-onset Parkinson's criteria. The investigational product is an allogeneic iPSC-derived dopaminergic neural progenitor cell preparation delivered by neurosurgical injection. The trial's primary focus is safety and tolerability with collection of preliminary efficacy signals on motor outcomes and fluctuations.

Who should consider this trial

Good fit: Ideal candidates are adults with early-onset Parkinson's (onset age 18–50) who are 18–70 at enrollment, have disease duration ≥5 years, a positive L-dopa response, off-period MDS‑UPDRS‑III >30, appropriate Hoehn‑Yahr grades, stable PD medications, and are medically fit for neurosurgery and anesthesia.

Not a fit: Patients unlikely to receive benefit include those without a clear L‑dopa response, those with late-onset or very advanced comorbid disease, significant cognitive impairment, or who are not suitable for neurosurgery or anesthesia.

Why it matters

Potential benefit: If successful, XS411 could replace or repair lost dopaminergic cells and reduce motor symptoms and medication-refractory motor fluctuations in early-onset Parkinson's patients.

How similar studies have performed: Related cell-transplant approaches, including fetal and stem-cell-derived dopaminergic grafts, have shown mixed but occasionally promising symptomatic benefit in small trials and preclinical studies, while allogeneic iPSC-derived therapies remain relatively novel with limited clinical data.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 18 years old ≤ age of onset ≤ 50 years old, diagnosed with EOPD (meeting the MDS 2015 clinical diagnostic criteria for Parkinson's disease );
* 18 years old ≤ age at enrollment ≤ 70 years old , male/female;
* Disease duration ≥ 5 years;
* Phase I: the modified Hoehn-Yahr grade in the off-phase is 3-4 (including the critical value) , and the modified Hoehn-Yahr grade in the on-phase is ≤3 ; Phase II: the modified Hoehn-Yahr grade in the off-phase is 2-4 (including the critical value) , and the modified Hoehn-Yahr grade in the on-phase is ≤3;
* Off-period MDS -UPDRS-III score \>30;
* Positive L-dopa stress test;
* The patient is unable to adequately control motor fluctuations even with a stable dose of medication recommended in the "Guidelines for the Treatment of Parkinson's Disease in China (Fourth Edition)" ;
* Patients received stable doses of anti-PD drugs for at least 4 weeks before administration;
* Able to accept surgical anesthesia, suitable for neurosurgery under anesthesia, and able to undergo brain CT /MRI examination;
* Participants agree to postpone any other elective neurosurgery until the completion of the 24-month follow-up study;
* Participants agreed not to participate in any other clinical studies within 24 months after dosing;
* Participants or their legal representatives understand and comply with the research procedures, voluntarily participate and sign the ICF

Exclusion Criteria:

* Non-primary PD or Parkinson's superimposed syndromes ;
* Patients are in the late stages of PD and are experiencing severe, disabling peak-dose dyskinesia or biphasic dyskinesia and/or unpredictable or widely fluctuating symptoms;
* Have previously undergone neuronucleotomy, deep brain stimulation (DBS), striatal surgery, extrapyramidal surgery, stereotactic brain surgery, or other brain surgery; or who have undergone other surgical procedures that the investigator determined would affect participation in this study; or who have surgical contraindications
* Patients currently receiving L-dopa intestinal instillation, apomorphine injection, or continuous daily infusion of anti-PD drugs;
* Patients who had used botulinum toxin, phenol, subarachnoid injection of baclofen, or received interventional treatment for dystonia or spasticity within 6 months before medication;
* Have used glucocorticoids or immunosuppressive drugs for a long time within 3 months before the screening visit;
* Those who have received cell therapy before;
* Patients who received electroconvulsive therapy within 30 days before administration;
* Those who have received or plan to receive vaccines during the trial within 3 months before screening, such as vaccines for novel coronavirus pneumonia (COVID-19), influenza, herpes zoster, and pneumococcal vaccine;
* Those with a history of mental illness who are judged by the researchers to be unsuitable for study participation; or those with severe suicidal ideation currently or within the year before screening or any history of suicide attempts within the past 2 years;
* Those with active epilepsy or currently taking anti-epileptic drugs;
* Those with a history of dementia or severe cognitive impairment; or those with obvious dementia or cognitive impairment at screening; dementia may affect participants' poor compliance, inability to accurately record diaries, and / or inability to sign the ICF;
* Severe anxiety at screening;
* Patients whose previous head CT/MRI examinations showed brain injuries such as brain trauma, cerebral vascular malformation, hydrocephalus, brain tumors, or abnormal brain imaging of the striatum and other brain regions, which significantly increased the surgical risk;
* Those with uncontrolled autoimmune diseases;
* Patients with a history of severe cardiovascular and cerebrovascular diseases;
* Patients with other serious systemic diseases;
* During the screening period, patients have severe arthritis, limp, severe sequelae of stroke, severe osteoporosis, or a history of severe trauma within 1 month (such as hip or lower limb fractures), which may affect the study evaluation as assessed by the researchers;
* Patients with malignant tumors or a history of malignant tumors;
* Patients with active disseminated intravascular coagulation and obvious bleeding tendency within 3 months before signing the ICF, or patients who cannot stop taking antiplatelet drugs or other anticoagulants for at least 10 days before surgery;
* Previous history of abnormal coagulation function;
* Patients with lab result abnormalities during screening include;
* Allergic to the drugs used in the study;
* Are pregnant or breastfeeding, or plan to become pregnant during the study;
* Female participants of fertile potential must have a positive pregnancy test result before dosing; female participants of fertile potential, or male participants who are not sterilized and whose partners are fertile, must not take effective contraceptive measures from the time they sign the ICF until at least 24 months after dosing; female participants must not agree to not donate eggs from the time they sign the ICF until at least 24 months after dosing, and male participants must not agree to not donate sperm from the time they sign the ICF until at least 24 months after dosing;
* Participants who are currently participating in other clinical trials, or have participated in other clinical studies and received intervention treatment within 1 month before administration;
* Those who are considered by the researchers to have poor compliance;
* Any other situation that the researcher deems to jeopardize the safety of the participants or affect the study evaluation.

Where this trial is running

Shanghai, Shanghai Municipality

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.
Conditions Parkinson Disease
Last reviewed 2026-06-13 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.