It’s been less than a year since we last reported on the CIRM-funded Asterias Biotherapeutics trial for spinal cord injury (SCI), and we already have more – still preliminary – but good news to share. The company recently released encouraging long-term follow-up results from their original Phase 1 clinical trial that suggest their stem cell treatment is safe and possibly effective for treating SCI occurring in the back region.
Back in August 2015, the California-based company reported positive results for the second phase of the clinical trial, the ongoing Phase 1/2a trial, that is testing their AST-OPC1 brain progenitor cell treatment in patients with cervical or neck spinal cord injury. They treated three patients with a low dose of two million AST-OPC1 cells and observed no serious side effects after two months. You can read more about these initial results in our blog.
Asterias plans to expand their Phase 1/2a trial by enrolling more patients and administering higher numbers of cells in hopes that a higher dose might impact or improve motor function in SCI patients. But with any cell transplantation therapy, there is always concerns about whether it’s safe and whether it could cause any long-term consequences in patients.
Good news to those who wait
A news release by Asterias yesterday, puts some of these fears to rest. They report new long-term data on their original Phase 1 trial, which was carried out by Geron, that treated patients with thoracic or back SCI. In this trial, five patients were treated with two million AST-OPC1 cells between 7 and 14 days post injury. The patients were given immunosuppressive drugs for two months so they wouldn’t reject the cell transplant and then were monitored over the next 4-5 years.
During this time, none of the patients showed any signs of transplant rejection, and MRI scans revealed that four out of the five patients showed less cavitation in their spinal cords, a destructive process that occurs after severe spinal cord injury.
Thus it seems that AST-OPC1 does not pose any serious safety issues for SCI patients, at least at the five-year mark. Chief Medical Officer Dr. Edward Wirth explained:
“This new long term follow-up data continues to support the general safety of AST-OPC1 and indicate minimal risk of the transplanted cells having unintended effects. In detailed immune response monitoring of patients, the results are consistent with long-term cell engraftment, immune system tolerability, and an absence of adverse effects. In short, AST-OPC1 does not appear to present any immunological or other long-term safety issues when administered to patients suffering from spinal cord injuries.”
These positive long-term results are perfectly timed for Asteria’s expansion of their Phase 1/2a trial where they aim to test doses of AST-OPC1 that they believe would improve motor function in SCI patients. Asterias CEO Steve Cartt commented:
“These new follow-up results are very encouraging and provide important further support for expansion of the ongoing Phase 1/2a clinical study in patients with complete cervical spinal cord injuries announced just last week. We are continuing to enroll patients in the second dose cohort of the current Phase 1/2a trial. Patients in this cohort are receiving a significantly higher dose of 10 million cells, which we believe corresponds to the doses that showed efficacy in animal studies.”
But that’s not all folks!
CIRM got the inside scoop on the next steps of this Phase 1/2a trial last week at a CIRM Alpha Stem Cell Clinics Meeting held at UC Irvine. Dr. Edward Wirth was the guest speaker, and during lunch, he explained how their recent successes in both clinical trials has prompted the FDA to grant them clearance to expand their current Phase 1/2a trial from 13 to up to 35 patients.
Asterias can now enroll patients with both AIS A (complete injury) and AIS B injuries and has expanded the age range of trial participants to 18-69 years. Dr. Wirth added that the goal of this trial is to rescue some of the motor function in cervical SCI patients so that they can go from needing full time care to being able to carry out some functions on their own. He also indicated that these patients will be monitored for 15 years to evaluate the safety and success of their treatment.
We at CIRM are encouraged by these early positive results and hopeful that this clinical trial will result in a stem cell treatment that will improve the lives of SCI patients.