Stem cell brain trial offers new hope for Parkinson’s patients

LOS ANGELES — Researchers at Keck Medicine of USC are conducting an early-phase clinical trial for a new Parkinson’s disease treatment that implants engineered stem cells into the brain to replace damaged neurons.

The experimental procedure aims to restore the brain's ability to produce dopamine, the depletion of which is a hallmark of the neurological disorder.

The U.S. Food and Drug Administration (FDA) has granted fast-track designation to the study, known as REPLACE™. The biotechnology firm Kenai Therapeutics developed the treatment.

Parkinson’s disease affects more than 1 million people in the United States. While current treatments can alleviate symptoms, they cannot stop or slow the progression of the disease.

During the procedure, neurosurgeons use MRI guidance to implant induced pluripotent stem cells (iPSCs) through a small hole in the skull into the brain’s basal ganglia.

These iPSCs are derived from adult human cells and reprogrammed to function as dopamine-producing brain cells.

Twelve patients will participate in the trial. Researchers will monitor the group for five years to evaluate the treatment’s long-term safety and efficacy.

A clinical trial underway at Keck Medicine represents more than a medical milestone; it signals a fundamental strategic pivot in the global approach to neurodegenerative disorders. By moving beyond palliative symptom management toward the regeneration of lost neurological function, the study aligns with the vanguard of regenerative medicine.

Central to this shift is the deployment of induced pluripotent stem cells (iPSCs). This methodology effectively bypasses the ethical and regulatory hurdles historically associated with embryonic stem cells by deriving therapy from adult skin or blood cells. The ability to engineer a standardized, scalable supply of dopamine-producing neurons is a breakthrough that, if validated, provides a foundational blueprint for tackling other high-burden pathologies such as Alzheimer’s and Huntington’s disease.

However, the path to market remains fraught with clinical and regulatory rigor. As a Phase 1 trial, the primary objective is safety rather than efficacy, with investigators closely monitoring for adverse events such as dyskinesia or infection. The decision to implement a five-year longitudinal observation period reflects a high degree of caution regarding long-term biological stability. While the FDA has granted the therapy an expedited regulatory pathway—acknowledging its transformative potential—the transition from a small 12-patient cohort to broad clinical approval is a multi-year undertaking. The forthcoming data from this initial group will serve as a bellwether for the future of regenerative neuroscience.

For Vietnamese American families—from our vibrant hubs in Little Saigon to those working across the nail salon and service industries—who are caring for loved ones with Parkinson’s, this research offers a tangible glimmer of hope. It underscores how the rapid advancements in American medicine can deliver the kind of breakthrough solutions that directly improve the quality of life for those in our community battling chronic and debilitating illnesses.