Flash Info Biotech

AUSTIN, Texas — Introgen Therapeutics today announced that ADVEXIN®
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 www.introgen.com.

“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.

About ADVEXIN

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.

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.