Doctors at Keck Medicine of USC are testing an experimental approach that implants lab-grown, dopamine-producing stem cells into the brain in an early-phase clinical trial for Parkinson’s disease.
The goal is to see whether specially engineered induced pluripotent stem cells (iPSCs) can replace damaged brain cells, restore dopamine production, and potentially improve motor function in people with moderate to moderate-severe Parkinson’s disease.
Parkinson’s disease is described as a long-term or progressive neurological disorder that worsens over time, and current treatments can ease symptoms but have not been proven to stop or slow the disease itself.
The trial targets dopamine loss, which the sources describe as closely linked to Parkinson’s symptoms because dopamine is a chemical messenger or neurotransmitter involved in movement and other functions such as memory and mood.
“If the brain can once again produce normal levels of dopamine, Parkinson’s disease may be slowed down and motor function restored,” said Brian Lee, MD, PhD, a neurosurgeon with Keck Medicine of USC and the study’s principal investigator.
How the implant works
The approach uses induced pluripotent stem cells, or iPSCs, which are made by reprogramming adult cells—such as skin or blood cells—back into a flexible state that can develop into many different cell types.
Researchers say these iPSCs are intended to mature into dopamine-producing brain cells and “jump-start” dopamine production in the brain.
“We believe that these iPSCs can reliably mature into dopamine-producing brain cells, and offer the best chance of jump-starting the brain’s dopamine production,” said Xenos Mason, MD, a neurologist at Keck Medicine of USC and a co-principal investigator on the study.
During the procedure, Lee creates a small opening in the skull to access the brain and implants the cells into the basal ganglia, a region described as responsible for coordinating or controlling movement.
The surgical team uses magnetic resonance imaging (MRI) guidance to place the stem cells precisely in that movement-control area.
What researchers will track
After surgery, participants are closely monitored for 12 to 15 months to track changes in Parkinson’s symptoms and to watch for possible side effects.
The sources specifically note that researchers will look for side effects including dyskinesia (excess movements) or infection.
Investigators also plan longer follow-up, continuing to monitor patients for up to five years to assess safety and outcomes over time.
“Our ultimate goal is to pioneer a technique that can repair patients’ motor function and offer them a better quality of life,” Lee said.
Trial size and oversight
Keck Medicine of USC is one of three sites in the United States participating in the multisite clinical trial.
Across all sites, the study includes 12 people with moderate to moderate-severe Parkinson’s disease, according to the sources.
The stem cell therapy is identified as RNDP-001 and is produced or manufactured by Kenai Therapeutics, which is described as a biotechnology company focused on treatments for neurological disorders or conditions.
The U.S. Food and Drug Administration granted the Phase 1 REPLACE clinical trial fast-track designation, which the sources say is intended to accelerate development and review.
One of the sources notes that the announcement about Keck Medicine’s research involvement is not soliciting participants.
Why dopamine matters in Parkinson’s
The sources describe Parkinson’s disease as being associated with reduced dopamine release or dopamine levels in the brain.
They also state that symptoms such as tremors, stiffness, and slowed movement are tied to the progressive loss of dopamine-producing brain cells, which disrupts the brain’s ability to regulate movement.
In the U.S., more than one million people are living with Parkinson’s disease, and about 90,000 new cases are diagnosed each year, according to the sources.
The trial’s central idea is that restoring dopamine production by replacing lost dopamine-producing cells could address a core feature of the disease, rather than only easing symptoms.
