Stem Cell Therapy Shows Promise in Spinal Cord Paralysis

Progenitor cells improve upper-extremity motor scores

Positive interim efficacy data have been reported from an ongoing phase 1/2a trial of AST-OPC1 (Asterias Biotherapeutics), an oligodendrocyte progenitor population derived from human embryonic stem cells, in patients with complete cervical spinal cord injury. While it is still early in the study, all of the patients have shown at least one motor level of improvement.

The response to treatment is being measured on the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) scale, which is widely used to quantify the functional status of patients with spinal cord injuries. As suggested by existing research, patients with complete cervical spinal cord injuries that show two motor levels of improvement on at least one side may regain the ability to perform daily activities, such as feeding, dressing, and bathing.

The efficacy target was recommended by the independent Spinal Cord Outcomes Partnership Endeavor (SCOPE) based on published data. SCOPE is affiliated with the American Spinal Injury Association.

In the ongoing study, cohort 1 consists of three patients who received a low dose of two million AST-OPC1 cells. The interim efficacy and safety results are as follows:

  • All of the patients have exhibited improved upper-extremity motor scores (UEMS) compared with baseline.
  • The average UEMS improvement for the three patients was 5.0 points at day 90, and they continued to improve an average of 7.0 points at 12 months.
  • Despite the low dose used in this safety cohort, at 12 months of follow-up, one patient improved one motor level on one side, and the remaining two patients improved one motor level on both sides.
  • The 12-month results from this cohort showed no serious adverse events related to AST-OPC1, to the injection procedure, or to immunosuppression with low-dose tacrolimus. In addition, data from the study indicated that AST-OPC1 can be safely administered to patients in the subacute period after severe cervical spinal cord injury.

Cohort 2 consists of five patients who received 10 million AST-OPC1 cells. The interim efficacy and safety results are as follows:

  • All of the patients dosed with 10 million cells have exhibited improved UEMS compared with baseline.
  • Four patients have reached the 90-day follow-up time point. All of these patients have improved one motor level on at least one side; two have improved two motor levels on at least one side; and one patient has improved two motor levels on both sides.
  • The average UEMS improvement in the four patients that reached the 90-day follow-up was 9.5 points.
  • The results to date from cohort 2 show no serious adverse events related to AST-OPC1, to the injection procedure, or to immunosuppression with low-dose tacrolimus. In addition, data from the study indicate that AST-OPC1 can be safely administered to patients in the subacute period after severe cervical spinal cord injury.

Efficacy results at six months after the implantation of 10 million AST-OPC1 cells in patients with complete cervical spinal cord injury will be available in January 2017. The data will focus on improvements in physical functioning of the upper extremities (i.e., fingers, hands, and arms) of each treated patient, as indicated by the ISNCSCI scale.

Source: Asterias Biotherapeutics; September 14, 2016.