Treatment represents a new approach that could potentially restore brain cells lost due to Parkinson’s disease
A stem cell-based therapy for the treatment of motor symptoms in Parkinson’s disease has received conditional, limited approval for use in Japan.
The dopamine neuron replacement treatment, known as raguneprocel but marketed under the name Amchepry, involves the reprogramming of adult cells from healthy donors into induced pluripotent stem (iPS) cells.
IPS cells behave like embryonic stem cells, meaning they can develop into almost any type of cell in the body. With Amchepry, researchers guide the iPS cells to become dopamine-producing cells. These cells are then surgically implanted into specific areas of a patient’s brain where dopamine neurons have been lost due to the disease.
The innovation was developed by Sumitomo Pharma in collaboration with Dr Jun Takahashi at Kyoto University. This treatment represents a new approach that could potentially restore brain cells lost due to Parkinson’s disease.
“The limited, conditional approval of raguneprocel marks a significant scientific milestone for the Parkinson’s community,” said Dr Brian Fiske chief scientist at The Michael J Fox Foundation in the US.
“It reflects decades of rigorous research into regenerative approaches, and while not available in the US, it offers encouraging evidence that cell-based therapies may one day become a meaningful part of Parkinson’s treatment.”
The therapy was evaluated in an early-stage clinical trial at Kyoto University Hospital involving seven people with Parkinson’s disease between the ages of 50 and 69. Participants were followed for 24 months after transplantation.
Among the six patients evaluated for motor outcomes, four showed potential clinical benefits when off medication and five when on medication. Brain imaging demonstrated dopamine production from the transplanted cells in the putamen. Researchers concluded that the transplanted cells survived, produced dopamine, did not form tumours and showed signs of potential clinical benefit.
Although study participants showed potential clinical benefits, the therapy is not a cure for Parkinson’s disease, and those receiving the therapy will likely need to continue taking levodopa, which the implanted cells could use to help produce dopamine. Additional data to confirm safety and demonstrate meaningful clinical benefits for treating motor symptoms of PD are also needed.
Japan has conditionally approved the treatment, meaning that the product is permitted on the condition that the company will conduct post-marketing surveillance and other studies to monitor efficacy and safety.
“I hope this will bring relief to patients not only in Japan but around the world,” said the country’s health minister Kenichiro Ueno. “We will promptly carry out all necessary procedures to ensure it reaches all patients without fail.”
Clinical trials of raguneprocel are currently underway in the University of California San Diego.
“I am pleased that our cell therapy for Parkinson’s disease has received approval from the Japanese regulatory authorities,” said Dr Takahashi.
“However, this approval is conditional, and further clinical studies involving additional patients across multiple institutions are required.
“Although the healthcare systems in the United States and Japan differ – and consequently the approaches to treatment development also vary – we share the same fundamental goal: to develop therapies that improve the well-being of patients. We will continue our efforts to advance and refine better treatments in the years ahead.”