Asterias’ embryonic stem cell therapy linked to sustained improvements in motor function in small spinal injury trial

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The data suggest Asterias' embryonic stem cell-based therapy may improve motor function.

Asterias Biotherapeutics has posted data from a phase 1/2a trial of its embryonic stem cell-based therapy. After six months, motor levels of all five evaluable patients who received a 10-million-cell dose have improved.

Fremont, California-based Asterias gave the 10-million-cell dose to six patients with cervical spinal cord injuries, five of whom have completed at least six months of follow-up. All five of the patients saw their motor level rise by at least one grade, on at least one side, against the International Standards for Neurological Classification of Spinal Cord Injury scale. The score of one of the five went up two levels on both sides. Another experienced a two-notch increase but only on one side. Patients’ Upper Extremity Motor Scores improved, too.

If the improvements are attributable to the therapy, the data suggest AST-OPC1 cells improve motor function in patients with the most severe form of spinal injury. The data also reveal a clean safety profile, with Asterias reporting no serious adverse events.

“The results to date in the 10 million cell cohort treated with AST-OPC1 cells show that the improvements in arm, hand and finger function observed very early in the study have been maintained and in most patients have even been further enhanced over time," Asterias CEO Steve Cartt said in a statement.

Asterias has several other data readouts lined up for the single-arm phase 1/2b trial, including a 12-month update on the cohort reported on this week. With that cohort fully enrolled, Asterias is also recruiting patients for a 20-million-cell arm and people with less-severe injuries for a second 10-million-cell group.

Such a succession of readouts looked impossible earlier this decade when financial troubles at Geron caused progress on the therapy to flounder. Asterias, with financial support from the California Institute for Regenerative Medicine, rescued the program and got it back into the clinic. Now, whatever fate awaits AST-OPC1, the therapy is at least moving forward again.

“These results to date are quite encouraging, and we look forward to initiating discussions with the FDA in mid-2017 to begin to determine the most appropriate clinical and regulatory path forward for this innovative therapy,” Cartt said.

Those discussions with FDA could lead to a more rigorous examination of the effect of AST-OPC1. Some patients with spinal injury experience spontaneous recovery. Asterias has put together matched historical data it claims show “a meaningful difference in the motor function recovery seen to date in patients treated with the 10 million cell dose of AST-OPC1.” But the jury will remain out until Asterias pushes ahead with plans to run a randomized controlled trial.

Shares in Asterias rose 4% in premarket trading, but then fell when trading began by more than 7% this morning.