Introgen Plans to Expand Biomarker Database in Phase 3 Trials and File BLA and MAA for ADVEXIN in Advanced Head and Neck Cancer in First Half of 2008

Introgen Therapeutics, Inc. (NASDAQ:INGN) announced today that upon the recommendation of its external regulatory and clinical advisors, the Company will include additional patient tissue samples from its Phase 3 trials for p53 biomarker analyses to predict ADVEXIN efficacy to strengthen its U.S. and European regulatory filings. This recommendation was made by the advisors without knowledge of Introgen’s Phase 3 clinical trial results. The Company expects to announce top-line Phase 3 data and submit its Biologics Licensing Application (BLA) and Marketing Authorization Application (MAA) for ADVEXIN for head and neck cancer in the first half of 2008. The Company’s MAA for ADVEXIN for the potential treatment of Li-Fraumeni Syndrome, a genetically inherited cancer, was accepted for filing by the European Medicines Agency (EMEA) last month under the EMEA’s Exceptional Circumstances rules. The additional tissue samples, which were previously unavailable, can now be collected upon appropriate consent and, in some cases, Institutional Review Board (IRB) approvals. The Company expects to capture an additional 20 percent or more of biomarker data through this effort, which its advisors believe will substantially strengthen the clinical data portion of its regulatory filings. "The Company feels that evaluation of all available data is critical to supporting the strongest possible regulatory application for ADVEXIN as a new treatment for patients with advanced head and neck cancer,” said Max W. Talbott, Introgen’s senior vice president of Regulatory Affairs. Abnormality of the p53 tumor suppressor is one of the most common and fundamental molecular defects in cancer and the target of ADVEXIN p53 therapy. Introgen has previously reported data from its earlier trials in head and neck, lung, prostate and Li-Fraumeni demonstrating statistically significant correlations between p53 biomarkers, tumor response or increased survival following treatment with ADVEXIN. The efficacy evaluation of the Phase 3 study will incorporate molecular biomarker analyses that assess p53 abnormalities and p53 protein levels in patients’ pre-treatment tumor samples. About ADVEXIN ADVEXIN is a targeted molecular therapy with the potential to be broadly applicable across a wide range of tumor types and clinical settings because it targets one of the most fundamental and common molecular defects, abnormal or blocked p53 tumor suppressor function, associated with cancer initiation, progression and treatment resistance. ADVEXIN has demonstrated increased survival and tumor growth control in recurrent head and neck cancer. About Introgen Therapeutics, Inc. Introgen Therapeutics, Inc. is a biopharmaceutical company focused on the development, manufacturing and commercialization of targeted tumor suppressors, a new class of therapies for the treatment of cancer. Introgen’s technology delivers targeted molecular therapies that increase production of normal cancer-fighting proteins and cytokines. The Company is developing a proprietary pipeline of product candidates utilizing molecular biomarkers to identify patients most likely to benefit from its therapies which target central cancer-causing mechanisms. Statements in this release that are not strictly historical may be "forward-looking” statements, including those relating to Introgen’s future success with its ADVEXIN clinical development program for treatment of cancer, its success in obtaining and analyzing additional tissue samples from patients treated with ADVEXIN, and its success in making regulatory filings in the U.S. and Europe in the first half of 2008. Only the FDA and EMEA can determine whether ADVEXIN can be marketed in the United States and Europe. The actual results may differ from those described in this release due to risks and uncertainties that exist in Introgen’s operations and business environment, including Introgen’s stage of product development and the limited experience in the development of gene-based drugs in general, dependence upon proprietary technology and the current competitive environment, history of operating losses and accumulated deficits, reliance on collaborative relationships, and uncertainties related to clinical trials, the safety and efficacy of Introgen’s product candidates, the ability to obtain the appropriate regulatory approvals, Introgen’s patent protection and market acceptance, as well as other risks detailed from time to time in Introgen’s filings with the Securities and Exchange Commission including its filings on Form 10-K and Form 10-Q. Introgen undertakes no obligation to publicly release the results of any revisions to any forward-looking statements that reflect events or circumstances arising after the date hereof. Editor's Note: For more information on Introgen Therapeutics, or for a menu of archived press releases, please visit Introgen’s Website at: www.introgen.com.