News Release

Geron Receives Favorable Ruling In Nuclear Transfer Patent Interference: Opponent´s Patent Claims Are Found Unpatentable, Geron’s Patent Claims Are Upheld

Menlo Park, CA–March 18, 2004–Geron Corporation (Nasdaq: GERN) announced today that the Board of Patent Appeals and Interferences of the U.S. Patent and Trademark Office has issued a decision on motions filed in the patent interference proceeding between Geron and Advanced Cell Technology Corporation of Worcester, Mass. ("ACT"). The decision finds all claims in the issued ACT nuclear transfer patent to be unpatentable. All motions filed by ACT were denied, including motions attacking the patentability of Geron’s claims.

This proceeding is one of two interferences that have so far been declared by the Patent Office, at Geron’s request, involving patents licensed to ACT. The patent involved is U.S. Patent No. 5,945,577 ("the ’577 patent"), which is licensed to ACT from the University of Massachusetts. Geron initiated these interference actions to clarify the parties" patent rights to nuclear transfer (animal cloning) technology, and to confirm the scope of those rights for companies that are Geron licensees.

In its decision, the Board found that all claims in the ’577 patent were unpatentable because the nuclear transfer method covered by the claims is not described in the patent application. The Board also scheduled a priority testimony phase, and has instructed ACT to submit evidence no later than May 1 in support of its asserted invention priority. If ACT elects to proceed, the priority testimony phase is expected to conclude later this year.

"We are pleased with the Board’s rulings," said David J. Earp, J.D., Ph.D., Geron’s vice president of intellectual property. "The Board agreed with us that the claims of the first ACT patent are unpatentable, and the basis on which the Board reached that decision applies equally to the ACT patent in the second interference. So, we expect the Board to find the claims in the second ACT patent to be unpatentable for the same reason. Moreover, in rejecting ACT’s arguments against the patentability of Geron’s claims, the Board’s opinion supports our view of the strength of our nuclear transfer patent position. While this does not formally end the interference, in order to proceed further, ACT will have to show that it invented this cloning technology as early as 1995, despite the fact that it did not file a patent application until 1997. And, ACT will have to do that in the context of this ruling that it is not entitled to any of the claims in its ’577 patent. We are confident that this technology was indeed invented first at the Roslin Institute and look forward to the conclusion of this case."

The Roslin/Geron nuclear transfer technology underlies the pioneering work at the Roslin Institute that led to the cloning of Dolly the sheep. Geron obtained rights to that technology when it acquired Roslin Bio–Med (now Geron Bio–Med) in 1999. As part of that acquisition, Geron obtained a worldwide license from the Roslin Institute to the nuclear transfer patent portfolio and assumed management of the patents. The portfolio now includes 3 issued U.S. patents, as well as granted patents in Europe, Australia, New Zealand, South Africa and several other jurisdictions.

In addition to the interferences with ACT, Geron was previously involved in a related patent interference with Infigen, Inc. of DeForest, Wisconsin. As announced in Geron’s January 27, 2004 press release on that interference, the Board entered judgment in Geron’s favor, upholding the patentability of all of Geron’s claims and denying a patent to Infigen.

The Board’s decision, in Patent Interference No. 104,746 (Stice v. Campbell), is expected to be posted on the Patent Office website at http://www.uspto.gov/web/offices/dcom/bpai/.

Geron is a biopharmaceutical company focused on developing and commercializing therapeutic and diagnostic products for cancer based on its telomerase technology, and cell–based therapeutics using its human embryonic stem cell technology.

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 future outcomes of patent proceedings constitute forward–looking statements involving risks and uncertainties, including, without limitation, risks inherent in 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 annual report on Form 10–K for the year ended December 31, 2003.

Contact:
Geron Corporation
David L. Greenwood
Chief Financial Officer
Tel: 650–473–7765
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