Geron Presents Data On HIV/AIDS Drug Candidate at the XVI International AIDS Conference.

MENLO PARK, Calif. -- Geron Corporation (Nasdaq:GERN) announced today the presentation of new data supporting the development of TAT0002, a small molecule telomerase activator for the treatment of HIV/AIDS, at the XVI International AIDS Conference in Toronto.

The data, which were presented by Calvin Harley, Ph.D., Geron's chief scientific officer, and co-authored by collaborating scientists at the Geffen School of Medicine at UCLA, confirm and extend earlier findings that TAT0002 enhances the function of key immune cells from HIV/AIDS donors. The results show that TAT0002 stimulates RANTES, MIP1-alpha and MIP1-beta, molecules that attract other immune cells to assist in the anti-viral response.

As in previous functional studies, the activity of TAT0002 was blocked by co-treatment with a potent and specific telomerase inhibitor, suggesting that TAT0002 works through telomerase activation. TAT0002 was previously shown to stimulate the production of IFN-gamma -- a molecule involved in the anti-viral response of cytotoxic CD8 T-cells specific for the HIV-1 AIDS virus -- and to enhance the ability of the CD8 cells to proliferate and kill HIV-1-infected CD4 cells.

Dr. Harley also presented data showing that TAT0002 is orally bioavailable in animals. These studies, in conjunction with pilot toxicology results, suggest that therapeutic blood levels of TAT0002 can be achieved with safe, oral doses of TAT0002.

"The new studies demonstrate that our orally available telomerase activator drug broadly reactivates anti-HIV immunity in AIDS patients' lymphocytes," said Thomas Okarma, Ph.D., M.D., Geron's president and chief executive officer. "The lymphocytes are the primary mechanism for containing HIV infection early in the course of the disease. Over time, telomere loss in these cells results in the gradual decline of their anti-HIV function, leading to clinical disease progression. Our hope is to use TAT0002 to prevent this immune decline and thereby prevent HIV progression."

TAT0002 is being developed at TA Therapeutics Ltd., a joint venture between Geron Corporation and the Biotechnology Research Corporation, a company established by the Hong Kong University of Science and Technology (HKUST). For more information on HKUST, visit www.ust.hk.

Geron is a Menlo Park, Calif.-based biopharmaceutical company that is developing and intends to commercialize first-in-class therapeutic products for the treatment of cancer and degenerative diseases, including spinal cord injury, heart failure, diabetes and HIV/AIDS. Geron's products are based on the company's core expertise in telomerase biology and human embryonic stem cells. 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 such forward-looking statements in this press release regarding future applications of Geron Corporation's telomerase activator compound 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 quarterly report on Form 10-Q for the quarter ended June 30, 2006.