Stem cell therapy shows promise for Parkinson's treatment

Scientists may be one step closer to using stem cells to treat patients with Parkinson's disease.

Carlsbad, CA-based International Stem Cell Corp. has developed a method to treat the common neurodegenerative disease by replacing lost neurons with new neuronal cells derived from human parthenogenetic stem cells (hpSC).

Researchers manufactured highly pure populations of neural brain cells differentiated from hpSCs and transplanted them into the brains of African Green monkeys and rats with animal versions of Parkinson's disease. These neuronal cells functioned similarly to adult cells, and the researchers said they expressed greater levels of dopamine--the neurotransmitter that is essential to Parkinson's disease--than previously reported approaches. 

"There is human data to suggest implanting neuronal cell into Parkinson's disease patients can have benefits on the symptoms," said Simon Craw, executive vice president of International Stem Cell Corp., to FierceBiotech Research, citing two past U.S. and Swedish studies. Previously, researchers had studied fetal neuronal cells in relation to treating neurogenerative disorders like Parkinson's. But Craw said there are two major problems associated with that research. First, the source of these cells presents an ethical issue since they must be taken from human fetuses, and second, fetal neuronal cell transplantation for Parkinson's has caused the movement disorder dyskinesia in some studies.

Researchers observed the rodents for 6 months and the primates for four months and saw behavioral improvements in both studies. There were no noticeable negative side effects, and the therapy did not produce any tumors in the animals. The company details its protocol in a paper in the Nature journal Scientific Reports and will present the research at the American Academy of Neurology's annual meeting in San Diego on March 20.

Every year, about 60,000 people are diagnosed with Parkinson's disease. While deep brain stimulation and levodopa can alleviate some of the symptoms of the disease, they tend to become less effective over time.

Craw said the company plans to submit an Investigational New Drug Application to the FDA within the next 12 months to move the therapy closer toward clinical trials.

- see the press release
- here's the study