"A genetically modified poliovirus may help some patients fight a deadly form of brain cancer researchers report. The experimental treatment seems to have extended survival in a small group of patients with glioblastoma https who faced a grim prognosis because standard treatments had failed Duke University researchers say. Ive been doing this for  years and Ive never seen results like this says Dr. Darell Bigner httpsneurosurgery.duke.edublogmeetdirectoremeritusbraintumorcenter the director emeritus of the The Preston Robert Tisch Brain Tumor Center at the Duke Cancer Institute who is helping develop the treatment. But the researchers and other braincancer doctors caution the research is at a very early stage. In the study only  percent of patients experienced a prolonged survival. Much more followup research is needed to better assess and hopefully improve the treatments effectiveness the researchers say. We have to be careful says Annick Desjardins https a Duke neurooncologist who helped conduct the study. But we have longterm survivors. We are seeing something we dont normally see with patients with glioblastoma. Dr. David Reardon http clinical director of the Center for NeuroOncology at the DanaFarber Cancer Institute in Boston says the Duke groups results may represent a good solid important step forward for patients with no alternatives. Article continues after this message from our sponsor Unfortunately for most patients this is not going to be the answer yet says Reardon who used to work at Duke but wasnt involved in the new research. My fear is that every patient and family dealing with the devastating disease of glioblastoma is going to think the poliovirus is the cure. Unfortunately the patients who are benefiting do reflect a relatively small percentage of the population. The Duke results were published  https Tuesday by the New England Journal of Medicine to coincide with their presentation at the nd International Conference on Brain Tumor Research in Norway. Glioblastoma is the most common and aggressive malignant brain tumor in adults. Its the cancer that killed former Sen. Edward Kennedy DMass. and former Vice President Joe Bidens son Beau. Sen. John McCain RAriz. is fighting glioblastoma. The Duke researchers decided to try to use a genetically modified version of the poliovirus https which can cause a devastating form of paralysis https because of the viruss ability to infect nervous system cells. The scientists removed one of the viruss genes to prevent it from causing polio and replaced that gene with one from a harmless virus known as a rhinovirus which ordinarily causes the common cold. The engineered virus was then infused directly into tumors in patients brains with a tube inserted through a hole in the skull. The modified virus retains the ability to infect and kill brain tumor cells and also appears to trigger the patients own immune system cells to attack the tumors the researchers say. Between  and  the researchers treated  patients trying various doses of the modified virus to determine which was safest and most effective. There are substantial risks. The treatment can cause a dangerous swelling in the brain that can lead to seizures and other complications the researchers found. One patient suffered a lifethreatening blood clot in the brain that required surgery. But overall the median length of survival was . months for patients treated with poliovirus compared with . months for a similar group of patients treated in the past the researchers report. And starting at two years after treatment the two groups survival rate began to diverge the researchers reported. After  months  percent of the patients treated with the virus had survived compared with  percent of the historical comparison group. After three years  percent of the poliovirus treated patients survived compared with  percent of the other group according to the researchers. Two patients have survived more than six years Bigner says. One has survived more than five years. You just dont see this percentage of longterm survivors with this disease Bigner says. Those that have survived more than two years are in remission and we expect them to continue to be longterm survivors. Some other researchers praised the results. Were extraordinarily encouraged by what we see with this data says Mitchel Berger httpneurosurgery.ucsf.eduindex.phpabout_us_faculty_berger.html chairman of neurosurgery at the University of California San Francisco and director of its center for brain tumors. Its phenomenal. But some cancer doctors caution that comparing the outcomes for patients receiving the virus treatment to what would have happened to similar patients in the past could produce misleading conclusions. The Duke researchers have started a followup study combining the treatment with a chemotherapy drug to try to improve the results. They also plan to combine the treatment with other drugs including some called checkpoint inhibitors https to harness the immune system to fight cancer. In addition the researchers are planning to try the approach on children with brain cancer as well as other types of cancer including melanoma and breast cancer. We believe we are going to be able to increase the results even more significantly Bigner says."