News Release

Geron Announces Presentation Of Data Supporting The Utility Of Small Molecule Telomerase Activators For HIV/AIDS Therapy

Menlo Park, CA March 7, 2005 –– Geron Corporation (Nasdaq: GERN) announced today the presentation of studies showing that its small molecule telomerase activators, GRN139951 and GRN140665, enhance the functional activity of immune cells from HIV/AIDS donors. The research, presented at the 2005 Palm Springs Symposium on HIV/AIDS, demonstrated that the Geron compounds increased the proliferative capacity of cytotoxic T–cells and their ability to produce a virus–fighting molecule, gamma Interferon (IFNã).

The new data, presented by Rita Effros, Ph.D., Elizabeth and Thomas Plott Endowed Chair in Gerontology, professor of pathology and laboratory medicine, and a member of the UCLA AIDS Institute at the David Geffen School of Medicine at UCLA, was the product of a joint research effort between Geron scientists and Dr. Effros and colleagues at UCLA. The 2005 Palm Springs Symposium was co–sponsored by the UCLA AIDS Institute.

During the progression of HIV disease, certain immune cells called CD8 + cytotoxic T–cells undergo accelerated replicative senescence (cellular aging), and lose their ability to proliferate and kill HIV–infected CD4+ T–cells. Previous work by Dr. Effros and colleagues demonstrated that introducing the telomerase gene into CD8+ cells from HIV/AIDS donors increased their proliferative capacity, their ability to produce IFNã, and their ability to inhibit viral replication and kill HIV–infected T–cells. The new work, presented for the first time at the Palm Springs Symposium, showed that Geron's small molecule telomerase activators have similar properties. Specifically, the studies indicated that both GRN139951 and GRN140665 stimulated T–cell proliferation and IFNã production. Preliminary data presented at the meeting also suggested that these molecules could increase the cytolytic (killing capacity) of CD8+ T–cells taken from a person infected with HIV.

"We were extremely pleased to discover that our small molecule compounds, GRN139951 and GRN140665, have positive effects in T–cells from HIV/AIDS donors," stated Calvin B. Harley, Ph.D., Geron's chief scientific officer. "As demonstrated by work from many laboratories with the telomerase gene, activation of telomerase has potential for the treatment of a broad range of degenerative diseases or chronic conditions in which cellular aging plays a role, including HIV/AIDS. We can now focus on the formal preclinical development of these drug candidates."

"This work is an important foundation for the research and development effort with GRN139951 and GRN140665 being undertaken by TA Therapeutics, Limited (TAT), a joint venture between Geron and the Biotechnology Research Corporation, Hong Kong," stated Thomas B. Okarma, Ph.D., M.D., Geron's president and chief executive officer. "In addition to the potential therapeutic opportunities in HIV/AIDS, these compounds may have therapeutic applications in many other chronic diseases in which cellular senescence plays a central role. The newly formed Hong Kong joint venture is funded and staffed to begin exploring these opportunities immediately."

Geron is a biopharmaceutical company developing and commercializing three groups of products: i) therapeutic products for oncology that target telomerase; ii) pharmaceuticals that activate telomerase in tissues impacted by senescence, injury or degenerative disease; and iii) cell–based therapies derived from its human embryonic stem cell platform for applications in multiple chronic diseases.

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 applications of Geron Corporation's technology and compounds constitute forward–looking statements involving risks and uncertainties, including, without limitation, risks inherent in the development and commercialization of potential products, need for additional capital, reliance on collaborators, need for regulatory approvals or clearances, 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, 2004.

Contact:
Geron Corporation
David L. Greenwood
EVP, CFO
Tel: 650–473–7765

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