Japan grants conditional, limited approval to a stem cell-based therapy for Parkinson’s  

A stem cell-based therapy for the treatment of motor symptoms in Parkinson’s, AMCHEPRY® (raguneprocel), has received conditional, limited approval for use in Japan. This therapy is designed to replace dopamine-producing brain cells that are lost in Parkinson’s. It is only available to eligible patients being treated within the Japanese health care system.

The decision was based on a small Phase I/II trial involving seven people with Parkinson’s who were followed for 24 months (see Clinical trials frequently asked questions for more information on what the different phases of trials mean). The company now has seven years to collect additional safety and effectiveness data in Japan to show whether the therapy should receive full approval.

How a stem cell-based “cell replacement” therapy works

The therapy is made from donor-derived induced pluripotent stem cells, or iPSCs. These donor cells are reprogrammed in the lab into early dopamine-producing nerve cells, which are then transplanted into the brain. Once transplanted, the hope is that the iPSCs survive, produce dopamine, and help reduce motor symptoms. While the therapy is promising, important questions remain about long-term safety, immune rejection, and how well the transplanted cells continue to function over time.

What this means for people living in Canada

This therapy is not approved in Canada and is not available here as part of standard Parkinson’s care. Access is currently limited to eligible patients treated within the Japanese health care system, and Japan’s approval pathway for regenerative medicine differs from Health Canada’s – so this decision does not change treatment options in Canada today.

Keeping expectations grounded

The early findings are encouraging, but the evidence so far is very limited. Larger studies are needed to confirm safety and effectiveness across a broader Parkinson’s population.

Be cautious about private clinics marketing stem cell interventions as proven treatments for Parkinson’s. Anyone considering this kind of therapy should speak with their neurologist or movement disorder specialist before making any decisions.

What happens next?

Next steps are straightforward: collect more safety and effectiveness data in Japan during the conditional period. Ongoing and future clinical trials will also help to clarify who benefits, for how long, and with what risks.

Learn more 

To learn more, read Parkinson Canada’s article, Stem cell-based therapies to treat Parkinson’s, as well as The Michael J. Fox Foundation’s coverage of Japan’s approval decision.