Geron Achieves Breakthrough in Scalable Growth of Human Embryonic Stem Cells
/FROM PR NEWSWIRE SAN FRANCISCO 415-543-7800/
TO BUSINESS AND MEDICAL EDITORS:
Geron Achieves Breakthrough in Scalable Growth of Human Embryonic Stem Cells
MENLO PARK, Calif., Oct. 1 /PRNewswire/ --
Geron Corporation (Nasdaq: GERN) announced the publication of research results
that describe the culture of human embryonic stem (hES) cells in the absence
of direct feeder cell support. The finding greatly facilitates the development
of scalable manufacturing processes to enable commercialization of hES
cell-based products.
Since their initial derivation in 1998, hES cells have been grown in
direct contact with mouse feeder cells. The mouse feeder cells supply
necessary components to maintain the pluripotent and proliferative capacity of
undifferentiated hES cells. In work published today in the journal Nature
Biotechnology, Geron scientists report that hES cell lines can be grown in the
absence of direct contact with mouse feeder cells. When hES cells were
cultivated in conditioned medium together with an extracellular matrix, the
hES cells proliferated in an undifferentiated state for more than 130
population doublings and maintained their ability to differentiate into all
three developmental lineages. The "feeder-free" hES populations maintained a
normal chromosomal complement and proliferated at the same rate as those cells
cultured on mouse feeder cells. The results demonstrate new culture conditions
that enable scale-up production and maintenance of the pluripotent state of
hES cells. Geron has filed worldwide patent applications covering this
technology.
The work has positive implications for the development of hES cell-based
commercial products. Elimination of feeder cells is essential for scalable
production of hES cell-based products. Moreover, conditioned medium from
well-characterized cell lines can be manufactured and tested in bulk
quantities, facilitating development of reproducible quality-controlled
processes for cell product manufacturing. "This development is important and
illustrative of our product development efforts at Geron to devise reliable
methods to produce cost effective cell-based products for both drug discovery
and regenerative medicine applications," said Thomas B. Okarma, Ph.D., M.D.,
Geron's president and chief executive officer.
Geron Corporation is a biopharmaceutical company focused on developing and
commercializing therapeutic and diagnostic products for applications in
oncology and regenerative medicine, and research tools for drug discovery.
Geron's product development programs are based upon three patented core
technologies: telomerase, human embryonic stem cells and nuclear transfer.
This news release may contain forward-looking statements made pursuant to
the "safe harbor" provisions of the Private Securities Litigation Reform Act
of 1995. Investors are cautioned that such forward-looking statements in this
press release regarding product development and future applications of Geron's
technology constitute forward-looking statements that involve risks and
uncertainties, including, without limitation, risks inherent in the
development and commercialization of potential products and the maintenance of
our intellectual property rights. Actual results may differ materially from
the results anticipated in these forward-looking statements. Additional
information on potential factors that could affect our results and other risks
and uncertainties are detailed from time to time in Geron's periodic reports,
including the quarterly report on Form 10-Q for the quarter ended June 30,
2001.
To receive an index and copies of recent press releases, call Geron's News
On Demand toll-free fax service, 1-800-782-3279. Additional information about
Geron Corporation can be obtained at geron.com
Geron Develops and Files Patents on Feeder-Free Growth Conditions for Human
Embryonic Stem Cells
Backgrounder
October 2001
Introduction
Human embryonic stem (hES) cells are capable of differentiating into all
major cell types of the body. In addition, hES cells have an unlimited
capacity to divide, making them a potential source of cells for the treatment
of numerous degenerative diseases.
Since their initial derivation in 1998, hES cells have been grown in
direct contact with mouse feeder cells. The mouse feeder cells supply
necessary components to maintain the pluripotent and proliferative capacity of
the undifferentiated hES cells. In work published in the October issue of
Nature Biotechnology, Geron scientists have discovered methods to maintain hES
cell growth in the absence of direct feeder cell support. These findings will
enable the development of scaled processes for the production of hES
cell-based products.
Isolation of hES Cells
hES cells were isolated by removing the inner cell mass (ICM) from embryos
donated under informed consent, produced from in vitro fertilization
procedures and no longer needed for reproductive purposes. The hES cells of
the ICM were then placed onto a layer of mouse fibroblasts. These mouse cells
serve as "feeders" and provide a substrate for the long-term maintenance and
proliferation of the undifferentiated cells. hES cells express the
immortalizing enzyme, telomerase, thereby giving hES cells the unlimited
capacity to divide. hES cells, when subsequently placed in appropriate culture
conditions, differentiate into functional cells representing all three
developmental lineages of the body, namely the endoderm, mesoderm, and
ectoderm.
The Development: "Feeder-Free" Culture of hES Cells
Although hES cells can be sustained on mouse feeder cells for an
indefinite period of time, this method requires the continual co-culture of
human and mouse cells, a method which is not easily amenable to scale-up and
yields hES cells contaminated by mouse cells and proteins. In the studies
reported in the October issue of Nature Biotechnology, Geron scientists
describe methods to grow hES cells in the absence of direct contact with
feeder cells. When the hES cells are cultivated in conditioned medium together
with an extracellular matrix, the hES cells will proliferate in an
undifferentiated state. The cells cultured without feeder cells proliferated
for over 130 population doublings yet maintained their ability to
differentiate into cells representing all three developmental lineages. The
"feeder-free" hES populations also maintained a normal complement of
chromosomes, and proliferated at the same rate as those cells cultured on
mouse feeder cells.
Implications of "Feeder-Free" Culture of hES Cells
The development of "feeder-free" methods to culture hES cells is a major
step forward in developing commercial scale processes to produce hES
cell-based products. Elimination of feeder cells simplifies the scale-up
production of hES cells. Extracelluar matrix components are characterized and
widely available from commercial sources. Conditioned medium from qualified,
well-characterized cell lines can be manufactured and tested in bulk
quantities, facilitating development of controlled reproducible processes for
manufacturing hES cell-based products.
Geron is developing processes to differentiate hES cells into several cell
types, including neurons, hepatocytes and cardiomyocytes. Geron has built a
patent portfolio of more than 30 patent applications related to hES cell
development technologies, including the feeder-free process published today.
hES Cell Product Applications
Geron's hES cell technology together with its proprietary platforms in
telomerase and nuclear transfer are being used to develop products for both
drug discovery and regenerative medicine applications. Today, in the drug
discovery process, normal primary tissue cells are not readily available, and
most candidate drugs are not tested early for their efficacy or safety in
primary human tissue samples. Instead, animal models are used. hES cells,
differentiated into any of a number of cell types, could be used to screen the
effectiveness or toxicity of new candidate drugs. hES cell derivatives could
also be used to create human cell models of the disease state being treated
and facilitate the selection of more efficacious drugs for development. hES
cell-based efficacy and toxicity screening could be implemented earlier in the
drug discovery process, accelerating drug development timeframes and
decreasing the risk of drug failures in clinical trials.
Geron is developing hES cell-based therapies for the treatment of a
variety of degenerative diseases. For instance, dopaminergic neurons derived
from hES cells could be used to treat Parkinson's disease. Likewise,
cardiomyocytes and hepatocytes differentiated from hES cells could be
transplanted to replace the lost function of these cells in patients with
congestive heart failure or liver disease.
Because of the unlimited growth potential of hES cells and Geron's ability
with telomerase to extend the replicative capacity of differentiated cells
produced from hES cells, the production of cells for transplantation
applications can occur in large batch manufacturing lots. This means that for
the first time, cell therapy products can be scalably produced in much the
same way monoclonal antibodies or protein biologicals are manufactured. This
will translate into low cost-of-goods manufacturing and distribution systems
that previously have been unachievable with traditional individualized cell
therapies.
Geron Corporation is a biopharmaceutical company focused on developing and
commercializing therapeutic and diagnostic products for applications in
oncology and regenerative medicine, and research tools for drug discovery.
Geron's product development programs are based upon three patented core
technologies: telomerase, human embryonic stem cells and nuclear transfer.
This backgrounder may contain forward-looking statements made pursuant to
the "safe harbor" provisions of the Private Securities Litigation Reform Act
of 1995. Investors are cautioned that such forward-looking statements in this
backgrounder regarding product development and future applications of Geron's
technology constitute forward-looking statements that involve risks and
uncertainties, including, without limitation, risks inherent in the
development and commercialization of potential products and the maintenance of
our intellectual property rights. Actual results may differ materially from
the results anticipated in these forward-looking statements. Additional
information on potential factors that could affect our results and other risks
and uncertainties are detailed from time to time in Geron's periodic reports,
including the quarterly report on Form 10-Q for the quarter ended June 30,
2001.
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SOURCE Geron Corporation
/CONTACT: investors and media, David L. Greenwood of Geron
Corporation,+1-650-473-7765; or investors, Nancy Robinson of Burns
McClellan,+1-415-352-6262, for Geron Corporation/
/Web site: geron.com
Oct-01-2001 11:31 GMT
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