Researching Regeneration: Dr. Damien Pearse Pursues Innovative Treatments for Spinal Cord Injury
Summary
- Dr. Damien Pearse’s laboratory investigates how to use Schwann cell transplants to repair the injured spinal cord.
- Dr. Pearse has done extensive research on finding effective treatments for chronic injuries of the spinal cord.
- After a successful Phase 1 trial, Dr. Pearse is gathering data to support FDA approval for Phase 1b/2 clinical trials aimed at demonstrating that Schwann cell transplants combined with biomaterials or drugs can be effective in improving spinal cord function.
Every time he goes to work, Damien Pearse, Ph.D., sees the people his research aims to help.
Dr. Pearse, a professor of neurological surgery at the University of Miami Miller School of Medicine, is a faculty member at The Miami Project to Cure Paralysis. The building that houses the project includes spaces for people with spinal cord injuries to access wellness programs and participate in clinical studies.
“Being able to frequently interact with people affected with spinal cord injury and other forms of paralysis is inspiring as a researcher, because often as scientists working in the laboratory, you may feel somewhat disconnected from the people you’re trying to help,” said Dr. Pearse, the John M. and Jocelyn H.K. Watkins Distinguished Chair in Cell Therapies.
Dr. Pearse is an expert in the biology of Schwann cells, the peripheral nervous system cells that play a key role in axon growth and myelination.
His lab investigates how to use Schwann cell transplants to repair the injured spinal cord. Along with fellow Miami Project researchers, Dr. Pearse has been involved in clinical trials that used Schwann cells from injured people’s own bodies to regenerate and reconnect damaged axons.
The main goal of my research would be to find a treatment that progresses into a medicine that can be used in people with spinal cord injury. Reaching such a milestone would be a tremendously humbling experience after the relentless pursuit of this goal.
Dr. Damian Pearse
About 18,000 people per year in the United States have a new spinal cord injury, according to the National Spinal Cord Injury Statistical Center. But more than 300,000 have chronic spinal cord issues, which are at least a year from the time of initial injury. It’s difficult to promote regeneration in these cases, Dr. Pearse said, because scar tissue blocks axons from regrowing.
“This research is long and labor-intensive,” he said. “But the majority of individuals with spinal cord injury have chronic injury, so we must continue to try to find an effective treatment.”
The Path to Schwann Cells
Dr. Pearse initially studied biotechnology, but pivoted to biomedicine while pursuing his Ph.D. During a research internship in 1999, he worked on peripheral nervous system regeneration.
“Unlike our central nervous system, brain and spinal cord, which has deficiency in regenerating after it’s injured, the peripheral nervous system can regenerate,” he explained. “Schwann cells are an integral part of that repair process.”
At a conference after his internship, Dr. Pearse met Professor Mary Bartlett Bunge, Ph.D., who performed pioneering research on Schwann cells with her husband, Richard.
Dr. Pearse decided this work was his calling. In 2000, he joined The Miami Project as a postdoctoral researcher.
He was thrilled to be part of a group of dedicated, knowledgeable scientists. He began studying therapies that combined Schwann cells with other approaches and continued this research when he joined the faculty in 2004.
Building on Phase 1 Trials
After performing pre-clinical investigations on Schwann cell transplants, Miami Project researchers received the OK from the U.S. Food and Drug Administration in 2012 to conduct Phase 1 clinical trials.
They found that transplantation using a person’s own Schwann cells was feasible and safe for several types of injuries in different parts of the spine — an important leap forward.
Now, Dr. Pearse’s lab is working on the next leap. They’re gathering data to support FDA approval for Phase 1b/2 clinical trials aimed at demonstrating that Schwann cell transplants combined with biomaterials or drugs can be effective in improving function.
“To give us the best chance of success, we want to build upon our previous work, which is showing that, when Schwann cells are combined with other promising therapies, we get a much more robust, reparative effect,” he said.
Finding the Best Schwann Cell-based Approach
Dr. Pearse’s lab is investigating many Schwann cell-based combinations.
“We want to make sure that the approach we select to use in a Phase 2 efficacy trial is the best, the one that we think has the highest chance of succeeding and potentially restoring the most function,” he said.
The approaches are designed to address challenges with Schwann cell transplants: their survival rate and ability to migrate from the injury site.
In spring 2024, Dr. Pearse received a Department of Defense grant to use Harvard University-based Gel4Mede’s biomaterial platform to create a “protective shield” and prevent cell damage during and after a transplant, as well as overcome the scar.
Another promising approach uses a molecule called polysialic acid. Dr. Pearse collaborated with the Urs Rutishauser lab at Memorial Sloan Kettering Cancer Center to demonstrate that Schwann cells with polysialic acid on their surface can migrate from an injury site and guide axons originating from the brain into and across the site to improve function.
Dr. Pearse is now trying to identify a biological method for attaching polysialic acid to Schwann cells in a way that prevents cells from over migrating.
Another approach avoids cell transplants entirely, instead using exosomes — nano-sized extracellular vesicles that transport material between cells.
“Exosomes from Schwann cells have been shown to carry beneficial cargos that promote axon protection and regeneration,” Dr. Pearse said.
In fall 2024, W. Dalton Dietrich, Ph.D., scientific director of The Miami Project and professor of neurological surgery at the Miller School, and a team including Dr. Pearse received a DOD grant to study the safety and benefits of these exosomes in spinal cord injury.
Determining the best approach to move toward clinical trials will take time. Dr. Pearse estimates he needs two to three years for the cell-based approaches and slightly less for the exosome-based approach.
Dr. Pearse said he’s honored to take his research from the lab to clinical trials, and grateful that he gets to find exciting discoveries with the team at The Miami Project.
“The main goal of my research would be to find a treatment that progresses into a medicine that can be used in people with spinal cord injury or similar conditions,” he said. “Reaching such a milestone would be a tremendously humbling experience after the relentless pursuit of this goal.”
Tags: Department of Neurological Surgery, Dr. Dalton Dietrich III, Dr. Damien Pearse, neurological surgery, Schwann cells, spinal cord injuries, The Miami Project to Cure Paralysis