Genetic Therapy Inc. said Monday that it initiated Phase I/II trialsusing its gene therapy technology to treat a form of metastatic centralnervous system cancer called leptomeningeal carcinomatosis.It is a late-stage disease in which tumor cells seed the membranescovering the brain and spinal cord that Genetic Therapy said affects 5percent to 20 percent of all cancer patients. The trial will be conductedat the National Institute of Neurological Disorders and Stroke at theNational Institutes of Health, in Bethesda, Md., and involve up to 24patients, Marc Schneebaum, the company's senior vice president andchief financial officer, told BioWorld."There may be a subset of patients where treating the disease may bebeneficial," Schneebaum said. Mean survival time for leptomeningealcarcinoma patients is about six months.The treatment uses Genetic Therapy's vector systems to transfer thegene for the enzyme thymidine kinase (HS-tk) into tumor cells. Whencells produce thymidine kinase, they become susceptible to the anti-viral drug ganciclovir, which is administered to destroy both the tumorcells that have expressed the enzyme and the cells used to produce theoriginal vector.A separate Phase I/II trial using the HS-tk technology is ongoing inbrain cancer patients.Genetic Therapy (NASDAQ:GTII) stock closed at $9.75 Monday,down 25 cents. _ Jim Shrine

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