Press Release: Introgen Therapeutics's INGN 225 Molecular Cancer Vaccine Demonstrates Promising Results In Phase 2 Trial

Introgen Therapeutics's INGN 225 Molecular Cancer Vaccine Demonstrates Promising Results In Phase 2 Trial AUSTIN, Texas -- Approximately half of patients with advanced small cell lung cancer responded to Introgen Therapeutics, Inc.'s INGN 225 molecular cancer vaccine in combination with subsequent chemotherapy. The encouraging Phase 2 clinical data were presented over the weekend by Introgen's collaborator Dr. Scott Antonia of the H. Lee Moffitt Cancer Center & Research Institute. Patients in the study achieved a 52 percent objective tumor response rate and 41 percent of patients were still alive one year after receiving the immunotherapy. Historically, tumor responses to second-line chemotherapy are between 6 and 30 percent and most patients survive for less than 6 months. The data imply that INGN 225 immunotherapy can sensitize cancer cells to the effects of chemotherapy restoring its effectiveness. INGN 225 is a cancer vaccine containing the p53 gene. p53 is called the "Guardian of the Genome," and is known to help restore normal cellular function and to promote apoptosis, or programmed cell death in abnormal cells such as cancer cells, allowing tumors to die when treated with chemotherapy. Dr. Antonia, associate professor in the Department of Interdisciplinary Oncology and Molecular Medicine, reported the data during the Fourth Biennial Meeting of Molecular Targets in Cancer Therapy in Clearwater Beach, Florida. An interim analysis of the phase 2 clinical trial was previously published in the medical journal Clinical Cancer Research. "Data from Introgen's study in lung cancer patients, as well as other published studies, supports the novel approach of using a combination of immunotherapy and chemotherapy to treat cancer patients," said Dr. Dmitry Gabrilovich, also of H. Lee Moffitt Cancer Center & Research Institute, organizer of the conference and co-principal investigator of the clinical trial. "INGN 225 sensitized tumors to the effects of platinum and taxane chemotherapies. Of particular interest, some patients who previously failed platinum chemotherapy responded to platinum re-treatment. These findings have important implications for improving the efficacy of these widely utilized cancer chemotherapies." INGN 225 is an immunotherapy (vaccine) that utilizes an adenovector to deliver the p53 gene to a patient's immune cells, stimulating an anti-tumor immune response. Induction of p53-specific immune responses were observed following INGN 225 therapy and were found to correlate with increased tumor responses to the administered chemotherapy. 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 therapies to treat a wide range of cancers using tumor suppressors and cytokines. Introgen maintains integrated research, development, manufacturing, clinical and regulatory departments and operates multiple manufacturing facilities including a commercial scale cGMP manufacturing facility. Statements in this release that are not strictly historical may be "forward-looking" statements, including those relating to Introgen's future success with its INGN 225 clinical development program for treatment of lung and other cancers. 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: Contact: Introgen Therapeutics, Inc. Naomi Puhl, 512-708-9310, ext. 341 [email protected]