New Parkinson's cell therapy shows initial success

A pilot study shows significantly improved motor parkinsonian symptoms without the dyskinesias usually caused by the transplant

It is not the first time that the Parkinson's Journal has reported on cell therapies at this point, but previous attempts in this direction have not been convincing.

The basic idea behind this therapy sounds simple: replace the perished dopaminergic cells in the substantia nigra of Parkinson's patients with specially cultivated dopaminergic progenitor cells with the aim of noticeably improving the motor symptoms. In this case, replacing means transplanting, and that was the biggest problem in the past, because the side effects of the transplant could hardly be controlled until now. In most studies, the rate of dyskinesia increased significantly as a result of the intervention.

New method for dividing fetal progenitor cells

The second problem that researchers faced in past studies was the source of the cells. Until now, fetal dopaminergic progenitor cells from aborted human fetuses have been used. However, they are not available in unlimited quantities and their use is questionable from an ethical point of view. To solve these problems, a working group from South Korea, together with researchers from the Technical University of Munich, developed a method with which the fetal dopaminergic precursor cells can be divided about 20 times and they were able to use special biomarkers to select the cells with a low risk of dyskinesia (Movement Disorders 2023, online January 24 https://doi.org/10.1002/mds.29316).

Progenitor cells from aborted fetuses

The progenitor cells were obtained from fetuses aborted in the 14th week of pregnancy. Before the cells were tested on humans, they were injected into mice, which showed neither increased mortality nor increased cancer susceptibility.

The 15 test subjects who were transplanted with the dopaminergic progenitor cells after this safety check were 60 years old on average and had had Parkinson's disease for about seven years. They were divided into three groups of five, each receiving different doses (4,12 and 40 million cells).

side effects during the study

what about the side effects during the pilot study?

Low dose group: 44 side effects

Intermediate dose group: 56 side effects

High dose group 24 side effects

From this it can be concluded that the dose has no effect on the frequency of side effects.

The toxic effects of the observed side effects were all less than or at most equal to grade 3.

Dyskinesia or even a deterioration in motor skills could not be observed in any case.

One study participant experienced a small, inconsequential hemorrhagic infarction one day after the cell transplant.

Typical postoperative pain could be successfully treated with analgesics.

What did cell therapy bring?

The changes were measured using the UPDRS-III scale, among other things, which proved that the improvement was essentially due to the dose level. An examination with a functional movement test (CAPSIT-PD) also showed noticeable improvements, both in the on and in the off status. The effects occurred in both halves of the body, both in the affected and in the less severely affected half of the body. That they were even more severe in the less affected half of the body suggests that earlier treatment could be far more effective.

And finally ...

There is a lot to be said for a therapeutic effect of this new cell therapy, which now has to prove its effectiveness in larger studies.

Jürgen Zender, February 2023