In Parkinson’s Disease patients develop neurological dysfunction as they lose a special kind of brain cell called dopaminergic (or dopamine) neurons. While a number of different approaches to this disease have been studied for decades, nothing has proven particularly successful in slowing its progression. As a result there has been a big need for novel thinking about how to tackle Parkinson’s Disease including via stem cells.
One of the most exciting ideas has been to use human induced pluripotent stem cells (hIPSC) or human embryonic stem cells (hESC) to make dopamine neurons or their precursors, which would then be transplanted into the brains of patients. hIPSC-based products have the potential advantage of being an autologous or “self” transplant not requiring immunosuppression, while hESC products would likely require immunosuppression, but could have other advantages.
A number of groups are pursuing the idea of “stem cells as a basis for treating Parkinson’s” and one, Jun Takahashi’s team in Japan, pulled the trigger (this link is to a Nature News article on this news by David Cyranoski) just weeks ago with their first trial participant.
It’s a historic moment with high hopes, but high risks too. Hope and risk often go hand-in-hand in clinical trials. Like other trials this one has a chance of either not working or of something going wrong, but I think it has a reasonable chance of success too based on the preliminary data and the solid logic behind the approach.
While the Takahashi trial was formally launched back in July, we now know that the 1st patient got transplanted in October, an important milestone. From the Cyranoski article:
“In October, neurosurgeon Takayuki Kikuchi at Kyoto University Hospital implanted 2.4 million dopamine precursor cells into the brain of a patient in his 50s. In the three-hour procedure, Kikuchi’s team deposited the cells into 12 sites, known to be centres of dopamine activity. Dopamine precursor cells have been shown to improve symptoms of Parkinson’s disease in monkeys.”
This trial is using allogeneic cells from a donor.
Other teams include that of Jeanne Loring at Scripps who is focusing on autologous IPSC-based therapies (see recent guest post by her), Lorenz Studer who is focusing on using hESC-based approaches (see my post on his talk at the annual ISSCR meeting this year in Melbourne), Roger Barker of Cambridge, and Malin Parmar at Lund University. An international collaborative group of some of these and other researchers is called GForce-PD.
You can see a cool image above of primate brain engrafted with IPS cell-derived neural precursor cells showing increased dopamine-related activity over time after the transplant in a Nature paper from last year by a team lead by Parmar and Takahashi.
We probably will know much more about the trend of this clinical trial within a year and can hope for a combination of signs of efficacy with a strong safety profile. I also am optimistic that more trials will begin in the next couple years in this area.