Spinal cord injuries (SCI) are caused by damage to the spinal cord resulting from trauma (e.g. a car crash) or from disease or degeneration (e.g. cancer).
SCI affects approximately 1.2 million people in the United States, and there are more than 11,000 new injuries per year. Half of those injuries are quadriplegic, with paralysis impacting all four limbs to some extent. For those individuals, the lifetime cost of managing their condition is estimated to be $2-3 million. SCI remains a major unmet medical need without any FDA-approved therapies or medical devices that improve or restore patient spinal cord function.
The leading causes of spinal cord injury are road traffic crashes, falls and violence (including attempted suicide). Symptoms of spinal cord injury may include partial or complete loss of sensory function or motor control of arms, legs and/or body. The most severe spinal cord injuries affect the systems that regulate bowel or bladder control, breathing, heart rate and blood pressure. Most people with spinal cord injury experience chronic pain. An estimated 20-30% of people with spinal cord injury show clinically significant signs of depression, which can have a serious negative impact on overall health.
Damage to the spinal cord causes a range of paralysis based on where it occurs. People with spinal cord trauma to the mid-back often retain the use of their hands and arms but can no longer walk and may lose bladder function. Patients with spinal cord injuries in their neck can be paralyzed completely from their neck down.
SCI affects approximately 1.2 million people in the United States, and there are more than 11,000 new injuries per year.
The medical, societal and economic burden of SCI is extraordinarily high. Traumatic SCI most commonly impacts individuals in their 20s and 30s, resulting in a high-level of permanent disability in young and previously healthy individuals. Direct costs of SCI are highest in the first year after the initial injury, and then generally decrease over time; however, indirect costs—particularly, in lost earnings—often exceed direct costs. Costs of spinal cord injury are higher than those of comparable conditions such as dementia, multiple sclerosis and cerebral palsy.
Progress Towards A Cure
California’s stem cell agency, the California Institute for Regenerative Medicine (CIRM) has made spinal cord injury (SCI) and paralysis major targets for research and therapy development, awarding more than $55 million to this area of research.
CIRM retains many grants for research to move potential spinal cord injury therapies forward. Much of this work focuses on trying to determine which type of nerve cell is the best one to transplant, and deciding which type of stem cell is the best starting point for making those cells. Other research is trying to see if these transplanted cells become part of the existing nerve system, helping create new pathways that can transmit nerve signals to muscles. The researchers are also looking at ways to try and improve the ability of these transplanted cells to become part of the nerve system. Each effort funded, whether successful or not, has been critical in developing foundational knowledge of what works—and what does not.
One promising CIRM-funded project, led by Dr. Jane Lebkowski at biotech company Asterias Biotherapeutics has seen promising early results from an ongoing Phase 1/2a human clinical trial to test a stem cell therapy for treatment of SCI.
Each effort funded, whether successful or not, has been critical in developing foundational knowledge of what works—and what does not.
Asterias has developed a stem cell therapy, called AST-OPC1, which uses oligodendrocyte progenitor cells (OPCs), a kind of cell found in the nervous system, to treat patients that have suffered from different types of spinal cord injury. OPCs are precursors to an important cell type in the central nervous system called the oligodendrocyte. These cells are responsible for forming a conductive sheet around nerve cells that allows nerves to send electrical signals and messages safely from one nerve to another. Both OPCs and oligodendrocytes provide support and protection to nerves in the spinal cord and brain, and they can also facilitate repair of damaged nerves by secreting survival and growth factors as well as promoting the formation of new blood vessels.
In this first part of the Phase 1/2a clinical trial, three patients with complete cervical (neck) spinal cord injuries were treated with this therapy, with no adverse events. If the team continues to see positive and safe results, they will turn to the Food and Drug Administration (FDA) for approval to expand the patient population of this clinical trial phase up to 40 patients.
CIRM is hopeful that Asterias will continue to see positive results with the SCiStar trial and will be able to progress into late-stage clinical trials, and eventually into an FDA-approved stem cell therapy for spinal cord injury.