New Phase III Data Confirm Phase II Findings of ADVEXIN(R) Efficacy

New Phase III Data Confirm Phase II Findings of ADVEXIN(R) Efficacy

Data Highlight p53 Biomarker Prediction of ADVEXIN(R) Clinical Benefit

AUSTIN, Texas--(BUSINESS WIRE)--April 13, 2008--Introgen Therapeutics, Inc. today announced that ADVEXIN(R) Phase III clinical trial data in patients with recurrent head and neck cancer confirm earlier Phase II results of ADVEXIN efficacy. Biomarkers of the p53 tumor suppressor gene target of ADVEXIN treatment were predictive in selecting patients more likely to respond to ADVEXIN, a targeted tumor suppressor therapy being investigated for a number of solid tumor cancers. Abnormal p53 tumor suppressor function is associated with cancer initiation, progression and treatment resistance and is one of the most fundamental and common molecular defects in cancers. Preliminary results from the phase III trial were presented today at the American Association for Cancer Research (AACR) annual meeting in San Diego, California. To access the AACR presentation please visit the Events page at

"ADVEXIN provides therapeutic benefit by restoring p53 tumor suppressor function which is blocked in the majority of head and neck cancers," said Robert E. Sobol, MD, senior vice president, Medical and Scientific Affairs, Introgen. "The strength of these p53 biomarker data provides important insights to help guide the future use of ADVEXIN treatment while advancing the field of personalized cancer care."

These data were generated from a phase III study that prospectively evaluated patients with biomarkers identified from earlier clinical studies. These results confirm the predictive value of p53 biomarkers hypothesized from previous phase I and II ADVEXIN clinical trials. The earlier studies included patients with recurrent squamous cell carcinoma of the head and neck (SCCHN), non-small cell lung cancer, prostate cancer and Li-Fraumeni Syndrome cancers. Previously reported preliminary results demonstrated a strong correlation between p53 biomarkers and increased tumor responses and survival following ADVEXIN therapy.

In the Phase III recurrent head and neck cancer trial, tumor response was correlated with a statistically significant increased survival. Importantly, p53 profiles favorable for ADVEXIN efficacy demonstrated a highly statistically significant correlation between ADVEXIN efficacy and tumor response. An analysis from recurrent SCCHN patients treated with ADVEXIN monotherapy in phase I, II and III trials showed tumor response in 79 percent of patients with p53 biomarkers favorable for ADVEXIN efficacy compared to 25 percent of patients with unfavorable p53 biomarkers for ADVEXIN (p=0.004 by Fisher's Exact Test).

"We are pleased with these positive preliminary phase III results," said Max W. Talbott, PhD, senior vice president, Regulatory and Worldwide Commercial Development, Introgen. "The Biological Activity Markers were incorporated into the original phase III study protocols and the finalized phase III Statistical Analysis Plan. Populations and endpoint combinations shown in this presentation were all prospectively identified."

A comprehensive analysis of Introgen's phase III data and additional pivotal studies of ADVEXIN in recurrent head and neck cancer, including prospective biomarker analyses demonstrating statistically significant correlations between p53 biomarkers and increased response and survival following ADVEXIN therapy, will be presented at medical conferences later this year. These and other data will be the basis for regulatory submissions in the United States and in Europe as previously reported.

About Biomarkers

Biomarkers are tests or measurements that predict response to treatment or increased survival following therapy. Introgen's molecular biomarkers include the identification of aberrant p53 function by standard assays performed by independent pathology laboratories worldwide that evaluate the sequence of p53 genes and abnormally elevated levels of p53 protein in tumor tissues. Introgen believes that application of p53 biomarkers can predict the patients who are most likely to benefit from ADVEXIN treatment. Similarly the biomarkers may also be used to predict which patients may benefit from other therapies and to identify patients that could be spared the side effects from toxic treatments unlikely to benefit the patient.


ADVEXIN p53 therapy is a targeted molecular therapy with broad applicability in a wide range of tumor types and clinical settings because it targets one of the most fundamental and common molecular defects, abnormal 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 patients. ADVEXIN has demonstrated clinical activity in a number of solid tumor types in multiple phase I, II and III clinical trials conducted worldwide.

About Introgen

Introgen Therapeutics, Inc. is a biopharmaceutical company focused on the discovery, development and commercialization of targeted molecular therapies for the treatment of cancer and other diseases. Introgen is developing molecular therapeutics, immunotherapies, vaccines and nano-particle tumor suppressor therapies to treat a wide range of cancers using tumor suppressors, cytokines and genes. Introgen maintains integrated research, development, manufacturing, clinical and regulatory departments and operates multiple manufacturing facilities including a commercial scale cGMP manufacturing facility.

Forward-Looking Statements

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 programs for treatment of cancer and the use of biomarker data to support the regulatory approval of ADVEXIN and improve the care of patients. 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.

The data, opinions and conclusions presented in this release and in the above referenced AACR presentation are preliminary. This information and additional relevant information have not yet been presented in their entirety to the U.S. Food and Drug Administration (FDA), European Medicines Evaluation Agency (EMEA) or other regulatory authorities; although we anticipate submitting materially all of this information to the FDA, EMEA and corresponding foreign authorities in the future.

Only the FDA, EMEA and corresponding regulatory agencies have the authority to approve pharmaceutical products. We cannot predict how such authorities may interpret the information contained in this release and the referenced AACR presentation or may respond to our regulatory submissions.

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