News Release

First In Vivo Proof-of-Concept Showing Impact of a Telomerase Activator in a Model of Human Disease

MENLO PARK, Calif., May 19, 2010 - Geron Corporation (Nasdaq: GERN) announced positive data on its orally available small molecule telomerase activator, TAT153, in an animal model of idiopathic pulmonary fibrosis (IPF). The data show that administration of TAT153 increased telomerase activity in the lung tissue, reduced inflammation, preserved functional lung tissue, slowed disease progression and attenuated loss of pulmonary function.

The data were presented at the American Thoracic Society 2010 International Conference in New Orleans, LA by Geron collaborator Dr. Claude Jourdan Le Saux from the University of Texas Health Science Center at San Antonio.

"This is the first demonstration that a telomerase activator can affect fibrotic disease progression in a model system," said Thomas B. Okarma, Ph.D., M.D., Geron's president and chief executive officer. "The data indicate that telomerase activation may be a useful therapeutic modality in IPF. Currently, there are no drugs that reduce the fibrotic process in lung disease or other organs. This is a very large unmet medical need."

Model System

The current study used a standard mouse model of IPF. The fibrotic process and accompanying deterioration of lung function were induced by bleomycin administration into the trachea. TAT153 was given twice daily for three weeks. Progression of pulmonary fibrosis in the animals was assessed by lung function tests, quantification of inflammatory cells and collagen deposits in the lungs.

Study Results

Inflammation precedes and is associated with fibrosis of the lung. Study animals showed a 40% decrease in inflammatory cells in the TAT153-treated group. Histology showed less extensive fibrosis preserving a greater proportion of functional lung tissue in treated animals.

The study included measurements of lung function in TAT153-treated animals and controls. The TAT153-treated animals showed a 30% increase in lung compliance (elasticity) and a 30% decrease in airway resistance (mechanical factors which limit the access of inspired air to the alveoli, or air sacs) compared to controls, demonstrating a significant attenuation of functional deterioration.

These positive effects of TAT153 in the mouse model of pulmonary fibrosis were associated with an approximately two-fold increase in telomerase activity in lung tissue samples.

About Idiopathic Pulmonary Fibrosis

Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, and usually fatal lung disease, characterized by inflammation and scarring, or fibrosis, of the lung. Patients have an impaired ability to process oxygen and a reduced lung volume and experience coughing and shortness of breath.

IPF affects 100,000 people in the U.S. and there are between 30,000 and 40,000 new cases each year. The median survival time from diagnosis is two to five years. The age of onset is between 40 and 70, with two thirds of patients older than 60 at presentation. Incidence rates are expected to be driven higher by an aging population. There are currently no FDA approved treatments for IPF.

The strong correlation between the onset of pulmonary fibrosis, including IPF, and telomere shortening in aged patients provides rationale for telomerase activation as a potential therapeutic approach for the disease.

About TAT153

TAT153 is a novel and proprietary chemical entity. Studies are underway to determine its suitability as a development candidate for fibrotic diseases, including IPF.

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 telomerase activation technologies 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-Q for the quarter ended March 31, 2010.

CONTACT:

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