Today, the Menlo Park-based biotech company Asterias Biotherapeutics reported positive results from the first three patients treated in its Phase 1/2a clinical study using stem cell therapy to treat patients with spinal cord injury. This trial is funded by a CIRM Strategic Partnerships Award grant of $14.3 million.

Asterias has developed a stem cell therapy called AST-OPC1 that 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. 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.

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 given a “low dose” of two million AST-OPC1 cells to test the safety and feasibility of their stem cell treatment. The first patient was treated at the Shepard Center in Atlanta,  and at the two month post-injection assessment, the patient experienced no side effects and an improvement from a complete to an incomplete injury on the ASIA impairment injury scale. The other two patients received injections at the Rush University Medical Center in Chicago. Both procedures were reported to have gone smoothly, and the patients are still being monitored.

Asterias plans to treat a second group of patients with higher doses of AST-OPC1 cells (10-20 millions cells). Chief Medical Officer Dr. Edward Wirth explained their strategy:

 The safety data in the first cohort now paves the way for testing the higher doses of AST-OPC1 (10-20 million cells) that we believe correspond most closely to the doses that showed the greatest efficacy in animal studies.

If both the low dose and high dose groups report no serious side effects, Asterias will turn to the Food and Drug Administration (FDA) for approval to expand the patient population of this clinical trial phase from 13 patients up to 40. Asterias hopes that adding more patients “will increase the statistical confidence of the safety and efficacy readouts, reduce the risks of the AST-OPC1 program and position the product for potential accelerated regulatory approvals.”

Spinal cord injury affects more than 12,000 people every year. It remains a major unmet medical need without any FDA-approved therapies or medical devices that improve or restore patient spinal cord function. CIRM is hopeful that Asterias will continue to see positive results with the SCiStar trial and will be able to progress its AST-OPC1 program into late-stage clinical trials and eventually into an FDA-approved stem cell therapy for spinal cord injury.

Related links

• Asterias press release: SCiStar Phase 1/2a Dose-Escalation Clinical Trial of AST-OPC1 for Complete Cervical Spinal Cord Injury
• Spinal cord injury and stem cell-based trials: What’s the latest (video featuring Jane Lebkowski, President of R&D at Asterias)
• CIRM press release: Treatment for spinal cord injury to start clinical trial funded by CIRM