A patient has undergone pioneering stem-cell therapy to treat Parkinson’s disease, the Japanese drugmaker behind the treatment said on Friday, in a world-first following its conditional approval in the country.

Sumitomo Pharma’s treatment involves transplanting millions of induced Pluripotent Stem (iPS) cells, which have the potential to develop into any cell in the body, into a patient’s brain.

Japanese regulators approved the groundbreaking therapy in March, following a successful clinical trial.

“The first transplant was performed at Kyoto University Hospital in October,” the company said on Friday in an earnings press release, without giving further details.

Parkinson’s disease is a chronic, degenerative neurological disorder that affects the body’s motor system, often causing shaking and other difficulties with movement.

Worldwide, more than 10 million people are estimated to have the illness, according to the Parkinson’s Foundation.

Currently available therapies “improve symptoms without slowing or halting the disease progression”, it says.

iPS cells are created by inducing mature, already specialised cells to return to a juvenile state.

Under Sumitomo Pharma’s treatment, iPS cells from healthy donors are developed into the precursors of dopamine-producing brain cells, which are no longer present in people with Parkinson’s.

During a clinical trial, seven patients aged between 50 and 69 each received implants of either five million or 10 million cells on both sides of the brain.

They were then monitored for two years, and no major adverse effects were found. Four patients showed improvements in symptoms.

Sumitomo Pharma said on Friday it plans to carry out transplants on 20 to 30 patients by March 2029. It is also carrying out a clinical trial in the United States.

The treatment will gain full approval in Japan if its safety and efficacy are confirmed over the next seven years, according to local media.

Friday’s announcement comes a month after a hospital in Osaka carried out the world’s first surgery using sheets of heart muscle iPS cells that can help form new blood vessels and restore heart function.

Japan also gave conditional approval to that therapy in March.