News Release

MENLO PARK, Calif., December 14, 2009 - Geron Corporation (Nasdaq: GERN) today announced that the U.S. Patent and Trademark Office, Board of Patent Appeals and Interferences, has granted Geron's request to declare an interference between a patent application owned by Geron and U.S. Patent No. 7,510,876 (the '876 patent) owned by Novocell, Inc. The patent filings cover technology for the differentiation of human embryonic stem cells (hESCs) into the precursors of numerous endoderm cell types, including pancreatic islet cells.

As part of its broad development pipeline of hESC-derived cell therapeutics, Geron is developing hESC-derived pancreatic islet cells for the treatment of diabetes. Geron holds an extensive global patent portfolio covering hESC technologies, including patents covering the most widely used method for producing islet cells from hESCs. Geron is also exclusively licensed for the production and therapeutic use of hESC-derived islets under the foundational hESC patents assigned to the Wisconsin Alumni Research Foundation.

"We believe that the '876 patent should not have been issued," said David J. Earp, J.D., Ph.D., Geron's chief patent counsel and senior vice president of business development. "The subject matter claimed in the '876 patent was disclosed in a Geron patent application filed more than two years before the corresponding series of Novocell applications. We filed the request for interference because we believe that Geron is entitled to claim this subject matter, and through this procedure the Patent Office will now reconsider its decision to grant the '876 patent. In preparation for the interference, the Patent Office has already determined that the claims of the '876 patent are patentable to Geron. If the Patent Office concludes that Geron invented the subject matter first, then the claims should be awarded to Geron."

Notably the '876 patent is one of a small number of patents that have been issued to Novocell from the same patent application family. Geron's view is that the interference proceeding for the '876 patent will also impact the validity of those other Novocell patents.

"Geron has pioneered the development of hESC technologies over the past decade, and we have been diligent to protect that technology, and the underlying investment, by building a dominant patent position," said Dr. Earp. "The strength of our technology and patent estate are reflected in the selection of Geron as a partner by a number of global industrial companies. As the need arises, such as in this instance, we will take the steps necessary to defend and protect our patents and our business interests. In our assessment no other company, including Novocell, has the freedom to operate to commercialize an hESC-derived diabetes therapy."

A patent interference is a proceeding conducted by the Patent Office in instances where two or more parties claim patent rights to the same technology. The U.S. patent system awards patents to the first party to invent a particular technology. In an interference, the Patent Office determines which party invented the technology first, and awards the patent to that party. The Patent Office presumes that the parties made their inventions in the order of the filing dates for their patent applications -- the party with the earliest filing date is referred to as the "senior party," while those with later filing dates are "junior parties." Unless a junior party can prove that, despite its later filing date, it actually invented the technology before the senior party, the patent is awarded to the senior party.

In this instance, the Patent Office has designated Geron as the senior party in the interference and Novocell as the junior party, because the Geron patent application has a filing date more than two years ahead of the '876 patent. As the junior party, Novocell will bear the burden of proof, and will have to show that its scientists invented the technology covered by the claims ahead of the Geron scientists in order to retain its patent.

Geron's portfolio of hESC-related patents includes 39 issued U.S. patents, 94 patents issued in other countries and more than 215 applications pending worldwide.

About Geron

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 in different cancers. For more information about Geron, 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 potential applications of Geron's human embryonic stem cell technology and the status of its intellectual property 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 Geron's 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 Geron's 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 September 30, 2009.

CONTACT:

Anna Krassowska, Ph.D.
Investor and Media Relations
650-473-7765
info@geron.com