Summary: Huntington’s disease is a progressive, ultimately fatal genetic disorder that destroys nerve cells in the brain, stripping people of motor control, cognitive abilities, and emotional stability. Symptoms typically appear in adulthood (most often between ages 35 and 50) and worsen steadily over a decade or more, placing a heavy emotional and financial burden on families. There are currently no approved therapies that halt or reverse the underlying neurodegeneration.
In a milestone for regenerative medicine, UCI Health has initiated the world’s first in-human clinical trial testing embryonic stem cell–derived neural stem cells for Huntington’s disease. The Phase 1b/2a study is evaluating an investigational cell therapy called hNSC-01, delivered directly into the brain using real-time MRI-guided stereotactic surgery.
This trial follows years of translational research at UC Irvine and is supported by a $12 million grant from the California Institute for Regenerative Medicine (CIRM). It aims to establish safety and gather early evidence of whether a targeted cellular therapy can slow disease progression, repair damaged brain circuits, and improve outcomes for people living with Huntington’s.
Key facts
- Global first: This is the first clinical trial to implant pluripotent embryonic stem cell–derived neural stem cells into people with Huntington’s disease.
- Therapeutic potential of hNSC-01: Preclinical studies indicate these cells can protect vulnerable neurons, replace lost cells, rebuild damaged circuits, release beneficial proteins such as brain-derived neurotrophic factor (BDNF), and help clear toxic protein aggregates.
- Precision delivery: The therapy is implanted directly into the striatum via a highly precise, intra-operative MRI-guided stereotactic procedure performed in a dedicated MRI suite.
- Initial safety milestone: The first participant received hNSC-01 at UCI Health – Irvine in May with no serious adverse events reported to date; a second participant is scheduled for July.
- Trial structure and enrollment: Coordinated through the UC Irvine Alpha Clinic, the study will enroll 21 participants aged 18–65 with early-stage Huntington’s: a Phase 1b dose-escalation cohort of 12 participants and a Phase 2a expansion cohort of 9 participants.
UCI Health launch
UCI Health, the clinical arm of the University of California, Irvine, is sponsoring and conducting the trial. The study evaluates the safety of hNSC-01 neural stem cells manufactured under Good Manufacturing Practice (GMP) conditions. The cells are implanted using a specialized neurological mapping and targeting stereotactic system while the patient lies in an intra-operative MRI scanner, enabling continuous visualization and millimeter-level targeting accuracy.
“This clinical trial highlights the important role that an interdisciplinary academic and clinical team together with HD families plays in advancing medicine,” said Leslie M. Thompson, Ph.D., the trial sponsor and Donald Bren Professor of Psychiatry and Human Behavior and of Neurobiology and Behavior at UC Irvine. “We are grateful to our patients and their families for their bravery and for providing hope for others with few options.”
The first intervention was performed at UCI Health – Irvine by neurosurgeon Jefferson W. Chen and an experienced surgical team. Dr. Ravi Rajmohan, the trial’s principal investigator, noted that the initial procedure went smoothly and that the first participant has not experienced serious adverse events to date. The study will continue close safety monitoring and comprehensive follow-up to detect any potential benefits or risks.
Why target the striatum?
Huntington’s disease primarily damages the striatum, a deep brain region that plays a central role in motor control, cognitive planning, and motivation. Loss of neurons and connections in the striatum produces the involuntary movements, cognitive decline, and mood disturbances characteristic of the disease. Delivering stem cells directly to this structure aims to place therapeutic cells where they are most needed.
About hNSC-01
hNSC-01 consists of pluripotent neural stem cells derived from embryonic stem cells and produced at a UC Davis GMP facility. In animal studies, these cells demonstrated long-term safety and multiple mechanisms of action: they protected existing neurons, replaced lost cells, promoted circuit reconstruction, released trophic factors like BDNF, and reduced toxic protein accumulations that harm brain cells.
How is the procedure performed?
Under general anesthesia, the patient undergoes a roughly six-hour operation inside an intra-operative MRI. Positioned face down in the scanner, the surgical team uses a proprietary navigation and delivery platform to guide fine instruments and deposit hNSC-01 cells precisely into the striatum while continuously imaging brain anatomy in real time.
Funding and coordination
The trial is supported by a $12 million grant from the California Institute for Regenerative Medicine (CIRM) and coordinated through the UC Irvine Alpha Clinic, the clinical component of the UC Irvine Sue & Bill Gross Stem Cell Research Center.
Participant impact and societal burden
Huntington’s disease progresses over years to decades, creating profound emotional and financial strain for people with the condition, their families, and caregivers. If hNSC-01 proves safe and shows signs of benefit, it could prolong independent living for patients and reduce long-term care needs and associated costs.
Frequently asked questions
Q: What is hNSC-01 and how might it address Huntington’s pathology?
A: hNSC-01 is a preparation of pluripotent neural stem cells derived from embryonic stem cells and manufactured under GMP conditions. In preclinical models the cells were safe and acted through several mechanisms: protecting surviving neurons, replacing lost cells, repairing neural circuits, decreasing toxic protein buildup, and releasing protective factors such as BDNF.
Q: Why use intra-operative MRI and stereotactic targeting?
A: The striatum lies deep within the brain and requires extremely precise targeting to avoid damaging healthy tissue. Intra-operative MRI combined with a stereotactic navigation system allows surgeons to visualize anatomy in real time and deliver cells with millimeter accuracy.
Q: Who can participate and how is the trial organized?
A: The trial will enroll 21 adults aged 18–65 with early-stage Huntington’s disease. It comprises a Phase 1b dose-escalation cohort of 12 participants to assess safety and dosing, followed by a Phase 2a expansion cohort of 9 participants to gather additional safety data and preliminary efficacy signals.
Editorial notes
- This article was edited by a Neuroscience News editor.
- Journal papers underlying the study were reviewed in full.
- Additional context was added by editorial staff.
About this research news
Author: Jessica Neuman
Source: UCI Health
Contact: Jessica Neuman – UCI Health
Image: Image credit: Neuroscience News