AST-OPC1 Stem Cell Therapy May Offer New Hope for Spinal Cord Injury
Richard G. Fessler, MD, PhD Comments
Researchers at Rush University Medical Center are part of a multicenter phase 1/2a trial investigating the use of oligodendrocyte progenitor cells AST-OPCI for treatment of subacute cervical spinal cord injuries.
“I have been doing this kind of research for more than 20 years, and I’ve never seen anything as encouraging as AST-OPC1,” said primary investigator Richard G. Fessler, MD, PhD, Professor of Neurological Surgery at Rush University Medical Center, Chicago, Illinois. “Although this is not a controlled study, I’m very excited by the early results,” Dr. Fessler told SpineUniverse.
Improvements in motor level have been seen as early as 30 days and, by 60 to 90 days, patients with C5 American Spinal Injury Association (ASIA) A levels of injury are getting return of function as far distally as 2 levels.
AST-OPC1 Induces Remyelination
AST-OPC1 is derived from human embryonic stem cells that are converted into oligodendrocyte progenitor cells. Previous laboratory studies suggest that the continuously regenerating AST-OPC1 produces neurotrophic factors, stimulate vascularization, and induce remyelination of denuded axons.
The phase 1/2a trial is designed to assess the safety and effectiveness of escalating AST-OPC1 doses (2-, 10-, or 20-million cells) administered at a single time-point between 14 and 30 days postinjury in individuals with a subacute, C5-C7, neurologically-complete cervical spinal cord injury. The primary outcome measure is the number of adverse events within 1 year (365 days) that are related to AST-OPC1 injection.
Preliminary Research Suggests Safety of AST-OPC1 Administration
No serious adverse events related to AST-OPC1, the injection procedure, or the accompanying short-course of tacrolimus have been reported in both the phase 1/2a trial and an earlier phase 1 safety trial involving 5 patients with neurologically complete T3-T11 thoracic spinal cord injury who received only the 2 million AST-OPC1 dose. In addition, no safety concerns were found on serial MRI scans during the four-year follow-up period in the phase 1 study, and no unexpected changes in neurological function were reported.
Thus far, Dr. Fessler and colleagues have injected 3 patients at the first dose level and 5 patients at the intermediate dose level.
Hand Function Is Returning in Some Patients
“Our preliminary results show that we may, in fact, be getting some regeneration. Some of those who have lost use of their hands are starting to get function back. That is the first time in history that’s ever been done,” Dr. Fessler said. “The unique aspect of this study, is that cells are being injected into the cervical spine where growth of even a centimeter or two can have dramatic effects on function.”
“In the future, this treatment may potentially be used for peripheral nerve injury or other conditions which affect the spinal cord, such as MS [multiple sclerosis],” Dr. Fessler said. While it does not appear likely that AST-OPC1 will be effective in people who have had spinal cord injuries for years, future studies are needed to assess efficacy in this patient population. In addition, Dr. Fessler said that the spinal cord needs to be in continuity and not severed for AST-OPC1 to work.
The study is funded by Asterias Biotherapeutics, which developed AST-OPC1, and also in part by a grant from the California Institute for Regenerative Medicine (CIRM). Early research results from the phase 1/2a trial were announced at the 55th Annual Scientific Meeting of the International Spinal Cord Society (ISCoS), held in Vienna, Austria, on September 14-16, 2016.