Introgen Therapeutics announced that its exclusively licensed European patent 0 760 675, directed to combination therapy with p53 and standard chemotherapy or radiotherapy, was upheld by the European Patent Office as amended following an opposition brought by Schering-Plough Corporation. The patent, exclusively licensed to Introgen from The Board of Regents of The University of Texas System, is one of the cornerstones of Introgen's formidable patent estate covering its Advexin Ad-p53 product candidate. This is the third successful outcome over a period of three years in oppositions involving Schering-Plough.

Dr. David L. Parker, Introgen's vice president for intellectual property said, "This is a very important win for Introgen on the European patent front. This patent is strategically important in that it covers the administration of p53, in any form, after the administration of virtually any type of conventional chemotherapy or radiotherapy. We are gratified to report that it has withstood the initial opposition and is a significant patent in our estate."

Introgen controls twenty-six issued patents and has a large number of pending United States and international applications that relate to its p53 technologies. Covered under the issued patents is the clinical use of adenoviral p53 in the treatment of cancer, as well as the use of p53 gene therapy in combination with conventional chemotherapy and radiation, regardless of the gene delivery system used. Introgen also owns an issued patent related to processes for the commercial scale production of adenoviruses.

Dr. Parker added, "This European patent compliments Introgen's multifaceted patent estate, which includes numerous patents on adenoviral p53, clinical therapy with adenoviral p53, combination p53 therapy with taxanes such as Taxotere or Taxol, and combination p53 therapy with other classes of chemotherapy drugs called DNA repair inhibitors."