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Biotech / Medical : Biotech Valuation -- Ignore unavailable to you. Want to Upgrade?

To: Biomaven who wrote (8273)	5/6/2003 5:45:32 PM
From: Biomaven	Read Replies (3) \| Respond to of 52153

This is interesting. I predict we are going to hear a lot more about the retinoblastoma (Rb) pathway over the next few years, although I don't know of any public biotechs currently doing much with Rb (Titan and Onyx have dabbled with it I think). Virus eradicates brain cancer in mice From the Science & Technology Desk Published 5/6/2003 4:42 PM View printer-friendly version HOUSTON, May 6 (UPI) -- Scientists said Tuesday they have created a virus that destroys deadly brain tumors in mice yet does not harm normal brain tissue. The therapy, which could be the first effective treatment for gliablastoma -- the deadliest form of brain cancer, looks so promising the National Cancer Institute is helping develop it for initial studies in humans, which could begin as soon as late next year. Conventional treatments for gliablastoma are not very effective and most patients will die less than two years after developing the cancer, but more than half of the mice treated with the virus in the study were cured of the cancer. "The results we saw were very, very impressive," the study's lead author Dr. Juan Fueyo, of M. D. Anderson's Department of Neuro-Oncology in Houston, told United Press International. Considering that no other treatment has shown this type of affect -- in animals or humans -- the results seen with this viral therapy are "extraordinary," Fueyo said. His team used a virus that normally causes the common cold called adenovirus and modified it so that it can only replicate in cancer cells not healthy cells. The virus, which they called Delta-24-RGD, infects and destroys tumor cells and when none of these are left, the virus dies. Dr. Howard Fine, director of the brain tumor program at NCI, told UPI the viral therapy "looks promising." But Fine noted, "A lot of approaches look promising in animal models ... It's a long ways off from saying (Delta-24-RGD) is going to work and make a difference in patients." In studies in mice, which appear in the May 7 issue of the Journal of the National Cancer Institute, the researchers found the viral therapy cured some mice of the brain cancer and significantly prolonged survival compared to mice that received no treatment. About 60 percent of mice with human gliablastoma tumors implanted in their brains survived for more than four months or the entire duration of the experiment after receiving Delta-24-RGD, whereas untreated mice died after less than 3 weeks. The virus appeared to completely eradicate the tumors in the mice that survived the entire study because they had only empty cavities and scar tissues where the tumors had once been. Fueyo's team contacted the National Cancer Institute and officials there were "enthusiastic," he said. "Now, NCI researchers are generating the Delta-24-RGD virus in their own lab and they are trying to build a virus with a purity that will allow administration to patients," he said. The research is being funded under an NCI program that was set up to provide financial support for academic institutions that develop innovative therapies but don't have the resources or technology to take it through the regulatory requirements to turn it into a drug, NCI's Fine explained. "It has to be reviewed and there has to be a certain amount of interest in it for NCI to fund it," he said. "But that's a long way from saying NCI is endorsing it. It just says that there 's enough preclinical data to be worthy of making the virus for testing" in humans. Delta-24-RGD "certainly deserves to be tested but the basic problem we face in brain tumor research is that it's a lot easier to cure brain tumors in animals than in people," Fine said. Fueyo agreed, saying that although the virus looks promising, the safety and efficacy of it will not be fully known until it is used in humans. He said his team will work with NCI scientists to "conduct more toxicity studies and if the virus passes all the toxicity tests, we will go to a clinical trial" in humans. They hope to begin tests in human patients by the winter of 2004. Fueyo's team made the Delta-24-RGD virus specific for tumor cells by targeting a protein that malfunctions in brain cancer. The protein, which is called retinoblastoma or Rb and is found in all cells of the body, helps regulate cell division but if it malfunctions a cell can divide repeatedly and result in a tumor. Rb also prevents viruses from infecting cells. Adenoviruses, however, produce a protein called E1A that binds to and blocks Rb, allowing the virus to enter cells and cause the common cold. The researchers tweaked the virus so it acted specifically on the malfunctioning form of the Rb protein, thus making it specific for infecting and killing only cancer cells. (Reported by Steve Mitchell, UPI Medical Correspondent, in Washington) Copyright © 2001-2003 United Press International