Geron Corporation (Nasdaq: GERN) today announced data on the use of GRNOPC1, oligodendrocyte progenitors derived from human embryonic stem cells, for myelin repair in a non-human primate model. The data supports further investigation of the potential therapeutic use of GRNOPC1 in central nervous system (CNS) disorders where the central or contributing pathology is destructive removal of myelin from nerve axons, such as observed in multiple sclerosis (MS), myelitis and spinal cord injury. GRNOPC1 is currently in a Phase 1 clinical trial in patients with spinal cord injury. The new data were presented at the 5 th Joint Triennial Congress of the European and Americas Committees for Treatment and Research in Multiple Sclerosis, in Amsterdam, by Prof. Jeffery D. Kocsis, Ph.D., from Yale University School of Medicine. The work was performed in collaboration with scientists at Geron. The studies utilized a non-human primate model where demyelinated lesions, such as seen in multiple sclerosis, were induced chemically in the spinal cord. GRNOPC1 was injected into the demyelinated spinal cord lesions one week after chemical induction. The lesion sites from six monkeys were analyzed using light and electron microscopy at various timepoints up to one year after injection of GRNOPC1 to look for evidence of cell survival and remyelination of nerve axons. In the first few weeks after implantation, the injection sites contained maturing transplanted cells indicative of a premyelinating phenotype with evidence of variable numbers and degrees of remyelinated axons. By four months post implantation, GRNOPC1 had induced extensive and thick myelin around the formerly denuded axons. Human cells were detected at the lesion site, providing evidence for survival of transplanted GRNOPC1. There was no evidence of abnormal tissue, tumor formation or other pathologies associated with the injection of GRNOPC1. Neurological exams of the injected animals were normal. The data showed in the non-human primate that GRNOPC1 can survive at the lesion site and progressively promote remyelination of axons.