In an early test of its therapy for Parkinson’s disease, International Stem Cell Corp. in San Diego said Monday that the stem cell-based treatment appears to be safe.
The first patient in the Phase 1 clinical trial, conducted in Australia, was treated at the end of July. A checkup three months later found no sign of complications, said Russell Kern, the company’s executive vice president and chief scientific officer.
In addition, there are some indications of efficacy in relieving symptoms of the movement disorder, Kern said after giving a presentation at the Society for Neuroscience’s 2016 convention in downtown San Diego. The conference is scheduled to run through Wednesday.
The patient’s handwriting has improved, Kern said. But because the trial is designed to measure safety, that’s considered a minor development that still needs to be confirmed. And more patients need to be treated.
“At least we can say there are no adverse events,” Kern said. The patient, a man in his 60s, is set to be examined again at the six-month mark.
The second patient will probably be treated in the next two to three weeks, Kern said. A total of 12 are expected to be treated.
Parkinson’s is caused by the destruction of brain cells that make the neurotransmitter dopamine. International Stem Cell’s therapy replaces these with new cells, grown from unfertilized, or parthenogenetic human egg cells. These cells act much like embryonic stem cells, and can be differentiated into cells that secrete dopamine.
Precursors to the dopamine-making cells are injected into the brain, where it’s hoped they will mature, take hold and produce dopamine, relieving Parkinson’s symptoms.
Cyto Therapeutics, a subsidiary of ISCO, is conducting the clinical trial in Australia, because its regulatory system allows work to proceed faster. It is performing the clinical trial at Royal Melbourne Hospital in Melbourne.
If the Phase 1 trial goes well, ISCO plans to ask permission to perform a Phase 2 trial in the United States, Kern said.
Other stem cell-based therapies are being readied for clinical trials. A group in San Diego, Summit for Stem Cell, proposes to use artificial embryonic stem cells made from patients to be treated.
Unlike true human embryonic stem cells, use of these induced pluripotent stem cells is regarded as ethically acceptable by those who oppose abortion, such as the Catholic church.
In late July, a Parkinson’s disease research project at The Scripps Research Institute in La Jolla supported by Summit for Stem Cell got $2.6 million to develop that therapy. The grant came from the California Institute for Regenerative Medicine, the state’s stem cell agency.
A similar therapy shows long-term signs of efficacy, according to Dr. Curt Freed, professor of medicine of the University of Colorado at Denver. This treatment uses human fetal dopamine-producing neurons, said Freed, who heads the university’s Division of Clinical Pharmacology and Toxicology.
The cells survive as long as 27 years, Freed told reporters Monday. The transplants make it possible for about 25 percent of patients to stop taking dopamine-producing drugs, Freed said. And there’s no need to take immuno-suppressive drugs to prevent rejection, he said.
One problem with this therapy is that fetal dopamine-making brain cells are limited in supply. In addition, the use of fetal tissue is controversial, Freed said.
“Dopamine-making neurons derived from stem cells could provide an infinite supply of cells, and not have the issue of using fetal tissue transplants,” he said.
