Introgen Therapeutics Inc and The University of Texas M. D. Anderson Cancer Center announced today that the United States Patent and Trademark Office has issued to The Board of Regents of The University of Texas System United States patent number 6,410,029 entitled "2-Methoxyestradiol- induced apoptosis in cancer cells." 2-methoxyestradiol (2ME2) is a potent anticancer agent and angiogenesis inhibitor and also rapidly and efficiently induces p53-mediated apoptosis, or programmed cell death.

The issued patent relates to the treatment of cancer by increasing expression of wild-type p53 in a cancer cell and inducing apoptosis with the introduction of 2ME2. It also relates to efficient transfer of wild-type p53 into a cancer cell that lacks functional p53. This type of treatment may further the development of a targeted approach to killing cancer cells. Introgen Therapeutics is the exclusive licensee of this patent.

The patent broadly applies to any type of vector used to deliver the p53 gene. When the level of p53 is increased in a target cancer cell through introduction of 2ME2, apoptosis occurs quickly and efficiently.

David L. Parker, Introgen's vice president of intellectual property said, "Our research programs continue to expand our understanding of the role of apoptosis, or programmed cell death, in cancer therapy. As demonstrated by this patent, our collaborators at M. D. Anderson have identified novel therapeutic strategies based on this new understanding. The technology underlying this patent paves the way for new, potentially less- toxic chemotherapies that take advantage of apoptosis as a therapeutic strategy, while sparing normal tissues."

2-methoxyestradiol is a natural metabolic byproduct of the human body formed by the hydroxylation of estradiol followed by O-methylation in the liver. Recent studies have shown 2-methoxyestradiol inhibits tumor cell growth through p53-mediated apoptosis and appears to be non-toxic to normal cells even at concentrations well above that needed to inhibit endothelial cell migration. This compound inhibits a key enzyme that is critical for cell survival. Since normal cells and cancer cells have different levels of this enzyme activity, 2-methoxyestradiol is expected to have selective activity against cancer cells.