Stem-Cell Medicine Test Shows Potential to Reduce Parkinson's Symptoms

Saturday - September 2 2023, 06:46 UTC - 1 year ago

In an important test for stem-cell medicine, a biotech company has found implants of lab-made neurons in the brains of 12 people with Parkinson’s to be safe and may have reduced symptoms for some of them. The small-scale trial, sponsored by BlueRock Therapeutics, used powerful stem cells from a human embryo and suggests there may be some benefits, but external experts are still cautious in interpreting the findings as some of the effects may be due to the placebo effect.

In an important test for stem-cell medicine, a biotech company says implants of lab-made neurons introduced into the brains of 12 people with Parkinson’s disease appear to be safe and may have reduced symptoms for some of them. The added cells should produce the neurotransmitter dopamine, a shortage of which is what produces the devastating symptoms of Parkinson’s, including problems moving. "The goal is that they form synapses and talk to other cells as if they were from the same person," says Claire Henchcliffe, a neurologist at the University of California, Irvine, who is one of the leaders of the study. "What’s so interesting is that you can deliver these cells and they can start talking to the host." .

The study is one of the largest and most costly tests yet of embryonic-stem-cell technology, the controversial and much-hyped approach of using stem cells taken from IVF embryos to produce replacement tissue and body parts.The small-scale trial, whose main aim was to demonstrate the safety of the approach, was sponsored by BlueRock Therapeutics, a subsidiary of the drug giant Bayer. The replacement neurons were manufactured using powerful stem cells originally sourced from a human embryo created an in vitro fertilization procedure.

According to data presented by Henchliffe and others on August 28 at the International Congress for Parkinson’s Disease and Movement Disorder in Copenhagen, there are also hints that the added cells had survived and were reducing patients’ symptoms a year after the treatment.These clues that the transplants helped came from brain scans that showed an increase in dopamine cells in the patients’ brains as well as a decrease in "off time," or the number of hours per day the volunteers felt they were incapacitated by their symptoms.

However, outside experts expressed caution in interpreting the findings, saying they seemed to show inconsistent effects—some of which might be due to the placebo effect, not the treatment. "It is encouraging that the trial has not led to any safety concerns and that there may be some benefits," says Roger Barker, who studies Parkinson’s disease at the University of Cambridge. But Barker called the evidence the transplanted cells had survived "a bit disappointing." .

Because researchers can’t see the cells directly once they are in a person’s head, they instead track their presence by giving people a radioactive precursor to dopamine and then watching its uptake in their brains in a PET scanner. To Barker, these results were not so strong and he says it’s "still a bit too early to know" whether the transplanted cells took hold and repaired the patients’ brains.

Embryonic stem cells were first isolated in 1998 at the University of Wisconsin from embryos made in fertility clinics. They are useful to scientists because they can be grown in the lab and, in theory, be coaxed to form any of the 200 or so cell types in the human body, prompting attempts to restore vision, cure diabetes, and reverse spinal cord injury. However, there is still no medical treatment based on embryonic stem cells, despite billions of dollars’ worth of research, in large part because they can also be controversial. Opponents, including religious groups, have argued that using such cells means destroying embryos that are potential human life.