Introgen's INGN 241 Cancer Therapy Triggers Immune System to Kill Cancer Cells (press release)

Researchers at Introgen Therapeutics, Inc. (Nasdaq: INGN - News) and their collaborators at The University of Texas M. D. Anderson Cancer Center have published new findings on the role of IL-24 in regulating the immune system in the current online issue of the Journal of Leukocyte Biology. MDA-7/IL-24 is the active component of INGN 241, an investigational cancer therapy currently in a Phase 2 trial in patients with malignant melanoma. A growing body of preclinical and clinical data indicates that INGN 241 stimulates the immune system to attack cancer cells through IL-24-dependent mechanisms.

"INGN 241 has been shown to exhibit a variety of anti-cancer activities, including inhibition of cancer cell growth and metastasis, reduction in the formation of new blood vessels necessary to support tumor growth and stimulation of the immune system to attack cancer," said Sunil Chada, Ph.D., Introgen's associate vice president, Clinical Research. "These new data detail the role that IL-24 plays in the normal immune response. We believe that further elucidation of the immune-enhancing activities of IL-24 further supports the development of INGN 241 as a novel cancer therapy that attacks tumors through several molecular pathways."

The paper describes the expression pattern of IL-24 in a variety of cell types following immune stimulation. Expression of IL-24 is increased by greater than 10,000-fold in specific cells that regulate the immune response. The data support an important role for IL-24 in regulating immune responses that occur as a result of viral or bacterial infection or tumor cell growth.

The studies were conducted in the laboratory of Elizabeth Grimm, Ph.D., Frances King Black Memorial Professor of Cancer Research in the Department of Experimental Therapeutics at M. D. Anderson Cancer Center. "Our data shows that activation of normal blood cells strongly induces IL-24 expression in key cellular regulators of the immune system. IL-24 induction is found as early as 1 hour after treatment, indicating that IL-24 may respond to "danger signals" from infections or cancer and amplify the immune response," said Dr. Grimm.

The mda-7 gene was discovered by the laboratory of Dr. Paul B. Fisher, professor of clinical pathology and the Michael and Stella Chernow Urological Cancer Research Scientist in the Departments of Neurological Surgery, Pathology and Urology at Columbia University. Introgen holds an exclusive worldwide license for all gene therapy applications from the Corixa Corporation.

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 non-integrating 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.

Introgen holds a licensing agreement with M. D. Anderson to commercialize products based on licensed technologies, and has the option to license future technologies under sponsored research agreements. Dr. Grimm is a paid consultant to Introgen, and is a member of Introgen's Scientific Advisory Board. The University of Texas System Board of Regents own stock in Introgen. These arrangements are managed in accordance with M. D. Anderson's conflict of interest policies.

Certain statements in this press release that are not strictly historical may be "forward-looking" statements, which are based on current expectations and entail various risks and uncertainties. Such forward-looking statements include, but are not limited to those relating to INGN 241 and its development as a monotherapy, as part of combination regimens, as an anti-angiogenic agent and as an immunotherapy. There can be no assurance that Introgen will be able to commercially develop gene-based drugs, that necessary regulatory approvals will be obtained or that any clinical trials or studies undertaken will be successful or that the proposed treatments will prove to be safe and/or effective. The actual results may differ from those described in this press release due to risks and uncertainties that exist in Introgen's operations and business environment, including, but not limited to, Introgen's stage of product development and the limited experience in the development of gene- based drugs in general, Introgen's 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 annual report on Form 10-K filed with the Securities and Exchange Commission on March 15, 2005 and its quarterly report on Form 10-Q filed with the Securities and Exchange Commission on May 10, 2005. 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.