Geron has presented new data showing that oligodendrocyte progenitor cells (OPCs) derived from human embryonic stem cells (hESCs), when transplanted into a rodent model of cervical spinal cord injury, reduced tissue damage within the lesion and improved recovery of locomotor function.
These data provide preclinical proof-of-concept for the use of GRNOPC1, Geron’s hESC-derived oligodendrocyte progenitor product, in patients with cervical spinal cord injuries.
The company said that the study, conducted in a cervical model of spinal cord injury, has demonstrated that injection of hESC-derived OPCs into the site of injury improved locomotor function with evidence of remyelination of nerve fibers.
The cervical injury model used in the study induced widespread tissue loss resulting in a cavity in the spinal cord. In contrast, there was no cavity in the spinal cord of the rodents that had been injected with hESC-derived OPCs seven days after injury, and the transplant area contained human oligodendrocytes.
These data provide in-vivo evidence that hESC-derived OPCs may protect the spinal cord from tissue damage induced by injury in addition to having a remyelinating function. Along with these observations, a decrease in genes associated with tissue damage and inflammation suggestive of a mechanism in which hESC-OPCs are exerting their tissue-sparing effect was noted.
Critically, the preservation of motor neurons within the spinal cord was shown to correlate with functional recovery. In the cervical injury model forelimb function was compromised. The animals that had received hESC-OPCs showed significantly greater improvement in forelimb stride length and range of motion compared to untreated controls.
Thomas Okarma, president and chief executive officer of Geron, said: “These preclinical studies demonstrate that transplantation of hESC-derived OPCs resulted in sparing of spinal cord tissue in the cervical lesion site. This sparing starts very soon after injection and importantly, results in the preservation of motor neurons which is correlated to recovery of forelimb movement. Our own IND-enabling safety and efficacy studies with GRNOPC1 in a cervical injury model are ongoing and will be submitted to the FDA upon completion.”