No Impact on Human Embryonic Stem Cell Therapeutic Product Development
MENLO PARK, Calif., Nov. 21, 2007 ? Geron Corporation (Nasdaq: GERN) today commented on the impact of recent advances in cellular reprogramming on the development of human embryonic stem cell (hESC)-based therapies.
Advances in Cellular Reprogramming
As reported yesterday, two laboratories have generated what appear to be pluripotent stem cell lines from human skin cells by permanently introducing a number of specific gene sequences into the genome via live viral vectors. The resulting ?induced? pluripotent stem cell lines (iPS) expressed genes characteristic of ?embryonic? human stem cell lines, proliferated in vitro at small scale for several months and displayed the ability to form teratomas and to undergo differentiation in vitro to several functional cell types. Although the iPS cells appear similar to human embryonic stem cells, they differed from hESCs in global gene expression patterns, with over 1000 genes differentially expressed, and they have not been extensively characterized.
No Impact on hESC Therapeutic Product Development
?This is beautiful science,? said Thomas Okarma, Ph.D., M.D., Geron?s president and CEO. ?These findings contribute to a better understanding of the molecular biology of cellular differentiation. The work will enable the generation of pluripotent lines from individuals who suffer from poorly understood genetic diseases. Such lines will be useful in understanding how certain abnormal genes induce dysfunction in particular cell types that lead to disease.?
?Yet the results are unlikely to impact the development of stem-cell based therapeutics,? continued Dr. Okarma. ?The notion of using an individually derived pluripotent stem cell line as the source for the manufacturing of a therapeutic cell type used only for that individual is not only extremely labor intensive and technically difficult, it is economically unfeasible. Moreover, the often stated reason to make individual lines is to avoid immune rejection as in organ transplantation. However, immune rejection may not pertain to cells manufactured from hESCs, as we have shown recently with our OPC1 cells, our hESC-based therapeutic for spinal cord injury. These therapeutic cells made from hESCs are immune-privileged and are not recognized by the human immune system in vitro (Journal of Neuroimmunology, December 2007, 192(1-2): 134-144).?
?What is most important to recognize is that an undifferentiated stem cell is not a therapeutic cell,? said Dr. Okarma. ?Geron has the preeminent global leadership position using our own patented technologies developed over many years to scalably and reliably manufacture therapeutic (differentiated) cells from pluripotent stem cell lines, regardless of their source. Indeed, one of the two labs successfully used Geron?s proprietary methods (Nature Biotechnology, September 2007, 25(9): 1015-1024) in order to produce cardiomyocytes from their iPS cell lines derived from human skin.?
Geron is developing first-in-class biopharmaceuticals for the treatment of cancer and chronic degenerative diseases, including spinal cord injury, heart failure and diabetes. The company is advancing an anti-cancer drug and a cancer vaccine that target the enzyme telomerase through multiple clinical trials. Geron is also the world leader in the development of human embryonic stem cell-based therapeutics, with its spinal cord injury treatment anticipated to be the first product to enter clinical development. For more information, visit www.geron.com.
