Introgen Therapeutics, Inc. and The Board of Regents of The University of Texas System announced that the United States Patent and Trademark Office has issued to The Board of Regents U.S. patent number 6,511,847 entitled "Recombinant p53 Adenovirus Methods and Compositions." Introgen Therapeutics is the exclusive licensee of this patent. The patent covers any adenoviral DNA molecules that encode the p53 gene positioned under the control of a particular gene regulator, called a promoter. Such a DNA molecule forms the genetic core of Introgen's Advexin cancer therapy.

David L. Parker, Ph.D., J.D., Introgen's vice president of intellectual property said, "This patent is of particular relevance to Introgen's Advexin program because it is a product patent that covers the core product DNA directly, which is the principal therapeutic element of Advexin.

"Introgen's Advexin therapy is now covered by up to 10 separate U.S. patents relevant to the product including compositions, therapeutic methods of administering the product in virtually any form, alone and in conjunction with the most widely used chemotherapeutic and radiation treatments, as well as its production," Dr. Parker added.

Introgen's Advexin therapy is a patented cancer therapeutic incorporating the p53 tumor-suppressor gene in an adenoviral delivery system. Advexin is designed to use the p53 gene to kill cancer cells and to stop tumor growth, without harming normal cells, in cancer patients with both normal and damaged p53 genes. The p53 gene interferes with cancer cells because it is a tumor- suppressor gene and carries instructions to make a protein that reacts with the damaged DNA of a cancer cell. Specifically, the p53 protein activates one of two pathways in these cells, to either stop growth by arresting cancer cell growth or inducing cancer cell death via a process of programmed cell death, called apoptosis. Both processes provide an important brake to the development of certain cancers.

Introgen's Advexin therapy uses the adenovirus delivery platform, a very important and frequently used tool in the fields of gene therapy and vaccines. Unlike other viral delivery systems, adenoviruses do not mix with a patient's DNA. Rather, they are genetically altered so that they are unable to replicate in humans and also have important properties that lend themselves readily to commercial scale manufacturing. With an excellent safety record, they have been used as gene transfer vectors in most clinical studies to date. The adenovirus has been used for many years in the vaccine field, and more recently as a powerful tool to develop gene therapies for a variety of conditions.