Irvine, California — UCI Health, the clinical enterprise of the University of California, Irvine, has announced the launch of the world’s first human clinical trial for Huntington’s disease using neural stem cells derived from embryonic stem cells, a development that could mark a major breakthrough in the treatment of this devastating genetic disorder.

Huntington’s disease is a progressive, incurable genetic condition that gradually destroys nerve cells in the brain, leading to the loss of motor, cognitive, and emotional functions. Symptoms typically appear between the ages of 35 and 50 and steadily worsen over a period of 10 to 20 years. Currently, no approved therapies are capable of stopping or reversing the neurodegeneration caused by the disease.

The Phase 1b/2a clinical trial, launched at UCI Health, is designed to evaluate the safety and preliminary efficacy of an innovative therapy known as hNSC-01. The treatment uses pluripotent neural stem cells derived from embryonic stem cells, which are implanted directly into the striatum—a deep brain structure affected by Huntington’s disease—during a sophisticated six-hour surgical procedure guided by real-time MRI imaging.

Researchers say preclinical animal studies have demonstrated that hNSC-01 cells can protect healthy neurons, replace lost cells, rebuild damaged neural circuits, secrete protective proteins such as brain-derived neurotrophic factor (BDNF), and reduce the accumulation of toxic proteins associated with the disease.

Leslie M. Thompson, Professor of Psychiatry and Human Behavior and Neurobiology and Behavior at the University of California, Irvine, and sponsor of the trial, said: “This clinical study highlights the critical role of collaboration among researchers, clinicians, and Huntington’s disease families in advancing medical science. We are deeply grateful to the patients and their families whose courage provides hope to others facing very limited treatment options.”

The first patient received the treatment at UCI Health–Irvine in May. According to Dr. Ravi Rajmohan, the study’s principal investigator, no serious adverse events have been reported in the patient to date. A second patient is scheduled to undergo the procedure in July.

The project is supported by a $12 million grant from the California Institute for Regenerative Medicine (CIRM) and is being conducted through the UC Irvine Alpha Clinic. A total of 21 patients aged 18 to 65 with early-stage Huntington’s disease will participate in the study. Of these, 12 will be enrolled in the Phase 1b dose-escalation cohort, while nine will take part in the Phase 2a expansion cohort.

Experts believe that if the therapy proves successful, it could slow—or potentially halt—the progression of Huntington’s disease, allowing patients to maintain their independence for longer periods. The treatment could also significantly reduce the emotional and financial burdens associated with long-term care.

As the first human study in the world to use embryonic stem cell-derived neural stem cells for Huntington’s disease, the trial represents a significant step forward in the development of regenerative therapies for neurodegenerative disorders.