Summary: Huntington’s disease is a progressive, ultimately fatal genetic disorder that destroys nerve cells in the brain, eroding motor control, cognition, and emotional stability. Symptoms most commonly appear between ages 35 and 50 and steadily worsen over years to decades, imposing severe emotional and financial burdens on patients and families. There are currently no approved therapies that stop or reverse the underlying neurodegeneration.
In a major medical milestone, UCI Health has launched the world’s first in-human clinical trial using embryonic stem cell-derived neural stem cells to treat Huntington’s disease. The Phase 1b/2a study evaluates an experimental cell therapy called hNSC-01, delivered directly into the brain through an advanced intra-operative MRI-guided surgical procedure. Supported by years of translational research and a $12 million award from the California Institute for Regenerative Medicine (CIRM), this trial represents an important step toward treatments that could slow or halt disease progression.
Key Facts
- First-in-human trial: This study is the first global effort to implant pluripotent embryonic stem cell-derived neural stem cells into people with Huntington’s disease.
- Therapy candidate — hNSC-01: Preclinical studies in animal models indicate hNSC-01 cells can protect vulnerable neurons, replace lost cells, rebuild impaired neural circuits, secrete brain-derived neurotrophic factor (BDNF), and help clear toxic protein aggregates linked to disease.
- Precision delivery: Cells are mapped and implanted into the striatum using real-time stereotactic navigation inside an MRI suite to maximize targeting accuracy and minimize damage to surrounding tissue.
- Initial safety milestone: The first patient received the transplant at UCI Health – Irvine in May with no serious adverse events reported so far; a second patient is scheduled for July.
- Trial design and enrollment: Coordinated by the UC Irvine Alpha Clinic, the trial will enroll 21 participants (ages 18–65) with early-stage Huntington’s disease: 12 in a Phase 1b dose-escalation cohort and 9 in a Phase 2a expansion cohort.
UCI Health clinical trial overview
The Phase 1b/2a trial evaluates the safety and feasibility of hNSC-01 neural stem cells derived from embryonic stem cells. The cells are manufactured under good manufacturing practices and are implanted using a specialized stereotactic system while the patient is positioned inside an intra-operative MRI. The trial team is led by Leslie M. Thompson, Ph.D., Donald Bren Professor of Psychiatry and Human Behavior and of Neurobiology and Behavior at UC Irvine, with clinical leadership and surgical care provided by UCI Health neurologists and neurosurgeons.
“This clinical trial highlights the important role that an interdisciplinary academic and clinical team, together with Huntington’s disease families, plays in advancing medicine,” said Dr. Thompson, the trial sponsor. “We are grateful to our patients and their families for their bravery and for offering hope to others who have very limited options.”
The first intervention was performed at UCI Health – Irvine, which hosts the region’s adult bone marrow/stem cell transplant and cellular therapy program. Neurosurgeon Dr. Jefferson W. Chen led the surgical procedure with a specialized team. UCI Health neurologist Dr. Ravi Rajmohan, the trial’s principal investigator, reported that the initial patient experienced no serious adverse events to date and emphasized that this research may bring the field closer to treatments that slow Huntington’s progression.
About Huntington’s disease and potential impact
Huntington’s disease is a hereditary neurodegenerative disorder that progressively impairs movement, cognition, and mood. Symptoms typically begin between ages 35 and 50 and worsen over 10 to 20 years, often leading to loss of independence and need for long-term care. If a cell therapy like hNSC-01 proves safe and effective, it could extend the period of independent living, reduce long-term care needs, and ease the financial and emotional burden on families.
What is hNSC-01 and how does it work?
hNSC-01 is an investigational therapy composed of pluripotent neural stem cells derived from embryonic stem cells and produced under GMP conditions. In animal models these cells demonstrated long-term safety and engaged in several potentially therapeutic actions: protecting remaining neurons, replacing lost or damaged cells, reconstructing neuronal circuits, releasing protective factors such as BDNF, and helping to reduce toxic protein build-up that contributes to neuronal death.
How are the cells delivered?
Cells are implanted during a single, approximately six-hour surgical procedure performed under general anesthesia inside an intra-operative MRI suite. Patients lie face down in the scanner while surgeons use a stereotactic navigation platform to visualize brain anatomy in real time and guide precise delivery into the striatum, a deep brain region critical for motor control, motivation, and cognitive function that is severely affected in Huntington’s disease. Participants will receive close follow-up to monitor safety and any early signs of benefit.
Funding and coordination
This clinical trial is funded by a $12 million grant from the California Institute for Regenerative Medicine (CIRM) and coordinated through the UC Irvine Alpha Clinic and the UC Irvine Sue & Bill Gross Stem Cell Research Center.
Key Questions Answered
A: hNSC-01 consists of pluripotent neural stem cells derived from embryonic stem cells and produced under GMP conditions. In animal studies the cells were safe long-term and acted through multiple mechanisms—protecting healthy neurons, replacing damaged cells, rebuilding neural circuits, reducing toxic protein accumulation, and secreting supportive factors like BDNF—aiming to alter the diseased brain’s structure rather than only treating symptoms.
A: Because Huntington’s disease targets the striatum, a deep, compact brain structure, delivering therapeutic cells requires extreme precision to avoid damaging surrounding tissue. Performing the surgery within an intra-operative MRI suite lets surgeons visualize the brain in real time and place cells exactly where they are needed.
A: The trial will enroll 21 adults ages 18–65 with early-stage Huntington’s disease. It is organized as a Phase 1b dose-escalation cohort of 12 participants followed by a Phase 2a expansion cohort of 9 participants to further evaluate safety and look for early signals of effectiveness.
Editorial Notes
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by staff.
About this stem cell and Huntington’s disease research news
Author: Jessica Neuman
Source: UCI Health
Contact: Jessica Neuman – UCI Health
Image: Credit to Neuroscience News