Japan announces world's first stem cell transplant for Parkinson's disease

Japanese pharmaceutical company Sumitomo Pharma has announced the world's first stem cell transplant procedure aimed at treating Parkinson's disease, carried out at Kyoto University Hospital in October after the therapy received conditional approval in Japan.

The company reported the operation was successful but did not provide further details. The procedure involves transplanting millions of induced pluripotent stem (iPS) cells into the patient's brain.

Conditional approval for the treatment was granted in March following a clinical trial involving seven patients aged between 50 and 69. During the trial, doctors implanted five or ten million cells into both sides of the brain. Over two years of monitoring, no major side effects were observed, and four patients showed improvement in symptoms.

The therapy uses iPS cells derived from healthy donors, which are developed into brain cells that produce dopamine, a neurotransmitter lost in Parkinson's disease. These cells are created by reprogramming mature cells back into a stem cell-like state.

Parkinson's disease, a chronic neurological disorder affecting movement, impacts more than 10 million people worldwide, according to the Parkinson's Foundation. While current treatments can help manage symptoms, they do not halt disease progression.

Sumitomo Pharma plans to expand the use of the therapy by transplanting cells into 20 to 30 patients by March 2029, alongside a clinical trial in the United States.

Full approval in Japan is expected within the next seven years, pending confirmation of the therapy's safety and effectiveness. If successful, the treatment could be adopted in other countries to combat Parkinson's disease.

This development follows an earlier milestone in Osaka, where a hospital performed the world's first iPS cell transplant for heart muscle, a procedure that may help form new blood vessels.