Combination Gene Therapy Containing p53 Gets U.S. Patent

The U.S. Patent and Trademark Office has issued a patent, "Methods and Compositions Comprising DNA Damaging Agents and p53" (No. 6,069,134), to the University of Texas (UT) System. The patent covers gene therapy using a p53 tumor suppressor gene in combination with one or more chemotherapeutic drugs, radiation therapies, or other agents that have a damaging effect on the DNA of cancer cells. The patented technology, which UT licensed to Introgen Therapeutics Inc. (Austin, TX), may be used either directly, in a non-viral delivery system, or in a viral delivery system.

The technology was developed by Jack A. Roth, chairman of the Department of Thoracic and Cardiovascular Surgery and co-director of the Keck Center for Cancer Gene Therapy at the University of Texas M. D. Anderson Cancer Center (Houston). Introgen and its collaborative partner Aventis Pharma AG are currently testing the p53 gene therapy as part of their Phase III pivotal trials for cancer of the head and neck, and as part of Phase I and II trials for other cancers including lung, prostate, ovarian, brain, and breast.

A p53 therapeutic could eventually be used alone or in combination with surgery, chemotherapy, and radiation therapy as a stand-alone cancer therapy, or to improve the efficacy of several chemotherapeutic agents. Study results suggest that cancer therapy with the p53 gene genetically programs the tumor cells to die or stop growing, whereas radiation therapy or chemotherapy kills or suppresses the growth of tumor cells through a direct damaging effect on their DNA. The expression of the normal p53 gene makes the cancer cell more sensitive to the effects of DNA damage by radiation and chemotherapy, and thus more easily killed.

David L. Parker, VP of intellectual property for Introgen, explained the scope of the patent in a company statement: "This patent broadly covers combination cancer therapy using the p53 gene, without regard to timing of radiation therapy or chemotherapy, and without regard to the method or route of delivery of the p53 gene. Since most cancer patients undergoing gene therapy will likely be treated with one or more forms of radiation therapy during their treatment regimen, this patent will be another important component of Introgen's intellectual property portfolio."

Introgen Therapeutics Inc. is a developer of gene therapy products for the treatment of cancer. The p53 patent is one of more than 200 patents that Introgen has licensed exclusively from The University of Texas M. D. Anderson Cancer Center.

For more information: C. Channing Burke, Introgen Therapeutics Inc., 301 Congress Ave., Ste. 1850, Austin, TX 78701. Tel: 512-708-9310, ext. 322. Fax: 512-708-9311.

Edited by Jim Pomager