With funding support from the California Institute for Regenerative Medicine (CIRM), Cedars-Sinai investigators have developed an investigational therapy using support cells and a protective protein that can be delivered past the blood-brain barrier. This combined stem cell and gene therapy can potentially protect diseased motor neurons in the spinal cord of patients with amyotrophic lateral sclerosis, a fatal neurological disorder known as ALS or Lou Gehrig’s disease.
In the first trial of its kind, the Cedars-Sinai team showed that delivery of this combined treatment is safe in humans. The findings were reported in the peer-reviewed journal Nature Medicine.
What causes ALS?
ALS is a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord. About 6,000 people are diagnosed with ALS each year in the U.S., and the average survival time is two to five years.
The disease results when the cells in the brain or spinal cord that instruct muscles to move—called motor neurons—die off. People with the disease lose the ability to move their muscles and, over time, the muscles atrophy and people become paralyzed and eventually die. There is no effective therapy for the disease.
Using Stem Cells to Treat ALS
In a news release, senior author Clive Svendsen, PhD, executive director of the Cedars-Sinai Board of Governors Regenerative Medicine Institute, says using stem cells shows lots of promise in treating patients with ALS.
“We were able to show that the engineered stem cell product can be safely transplanted in the human spinal cord. And after a one-time treatment, these cells can survive and produce an important protein for over three years that is known to protect motor neurons that die in ALS,” Svendsen says.
Aimed at preserving leg function in patients with ALS, the engineered cells could pave the way to a therapeutic option for this disease that causes progressive muscle paralysis, robbing people of their ability to move, speak and breathe.
The study used stem cells originally designed in Svendsen’s laboratory to produce a protein called glial cell line-derived neurotrophic factor (GDNF). This protein can promote the survival of motor neurons, which are the cells that pass signals from the brain or spinal cord to a muscle to enable movement.
In patients with ALS, diseased glial cells can become less supportive of motor neurons, and these motor neurons progressively degenerate, causing paralysis.
By transplanting the engineered protein-producing stem cells in the central nervous system, where the compromised motor neurons are located, these stem cells can turn into new supportive glial cells and release the protective protein GDNF, which together helps the motor neurons stay alive.
Ensuring Safety in the Trial
The primary goal of the trial was to ensure that delivering the cells releasing GDNF to the spinal cord did not have any safety issues or negative effects on leg function.
In this trial, none of the 18 patients treated with the therapy—developed by Cedars-Sinai scientists and funded by CIRM—had serious side effects after the transplantation, according to the data.
Because patients with ALS usually lose strength in both legs at a similar rate, investigators transplanted the stem cell-gene product into only one side of the spinal cord so that the therapeutic effect on the treated leg could be directly compared to the untreated leg.
After the transplantation, patients were followed for a year so the team could measure the strength in the treated and untreated legs. The goal of the trial was to test for safety, which was confirmed, as there was no negative effect of the cell transplant on muscle strength in the treated leg compared to the untreated leg.
Investigators expect to start a new study with more patients soon. They will be targeting lower in the spinal cord and enrolling patients at an earlier stage of the disease to increase the chances of seeing effects of the cells on the progression of ALS.
“We are very grateful to all the participants in the study,” said Svendsen. “ALS is a very tough disease to treat, and this research gives us hope that we are getting closer to finding ways to slow down this disease.”
The Cedars-Sinai team is also using the GDNF-secreting stem cells in another CIRM-funded clinical trial for ALS, transplanting the cells into a specific brain region, called the motor cortex that controls the initiation of movement in the hand. The clinical trial is also funded by CIRM.
The California Institute for Regenerative Medicine (CIRM) remains committed to funding research and clinical trials to treat ALS. To date, CIRM has provided $93 million in funding for research to treat ALS.
Read the original source release of the study here.