News Release

U.S. Patent Office Upholds Two Additional Human Embryonic Stem Cell Patents in Reexamination Decisions

MENLO PARK, Calif., March 11, 2008 – Geron Corporation (Nasdaq: GERN) announced today that the U.S. Patent Office has upheld the validity of two additional patents for human embryonic stem cells (hESCs) that were challenged through reexamination proceedings.

In its latest communication, the Patent Office issued Notices of Intent to Issue Ex Parte Reexamination Certificates for U.S. Patent Numbers 5,843,780 and 6,200,806, which claim preparations of, respectively, primate and human embryonic stem cells and methods for their isolation. During the proceedings, the Wisconsin Alumni Research Foundation (WARF), an organization to which the patents are assigned, made minor amendments to certain claims to improve clarity and consistency and added three new claims to each patent. The decisions of the Patent Office on these two patents are final and cannot be appealed.

Last month, the Patent Office upheld the claims of a related third patent: U.S. Patent Number 7,029,913. All three patents are assigned to WARF and licensed exclusively to Geron for the development and commercialization of therapies based on three types of cells derived from hESCs: neural cells, cardiomyocytes and pancreatic islet cells. Geron is also licensed non–exclusively for the development and commercialization of other cell types derived from hESCs for therapeutic and non–therapeutic uses.

"We are pleased that the Patent Office has reconfirmed the validity of all three of the patents," said David J. Earp, J.D., Ph.D., Geron’s chief patent counsel and senior vice president of business development. "The reexamination proceedings were detailed and comprehensive, and the positive outcomes have strengthened the patents."

As the world leader in the development of human embryonic stem cell–based therapeutics, Geron holds a broad portfolio of intellectual property rights, including the WARF patents discussed above, additional WARF patents that are not subject to the reexamination proceedings and patents exclusively licensed from the University of California and the University of Oxford. In addition, Geron’s portfolio includes patents and patent applications owned and filed by Geron to cover technologies developed internally by Geron scientists enabling the scalable production and differentiation of hESCs. Geron’s stem cell–related patent portfolio includes 36 issued or allowed U.S. patents, 69 patents granted or accepted in other countries and more than 230 applications pending worldwide.

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.

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 statements in this press release regarding intellectual property strength and potential applications of Geron’s human embryonic stem cell technology constitute forward–looking statements that involve risks and uncertainties, including, without limitation, risks inherent in the development and commercialization of potential products, uncertainty of clinical trial results or regulatory approvals or clearances, need for future capital, dependence upon collaborators and 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 annual report on Form 10–K for the year ended December 31, 2007.

CONTACTS:

Media and Investors: David Schull, Russo Partners, LLC, 858–717–2310,
david.schull@russopartnersllc.com

Tracey Milani, Russo Partners, LLC, 619–814–3511,
tracey.milani@russopartnersllc.com

At Geron: David L. Greenwood, Chief Financial Officer, 650–473–7765, info@geron.com

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