"An experimental drug for treating Alzheimers disease that previously showed troubling side effects may actually be safe in the long run researchers report. The keys to the safety of the drug bapineuzumab may be lowering the dose and not giving it to patients with ApoE a gene mutation linked to Alzheimers according to two studies scheduled for presentation Wednesday at the Alzheimers Association International Conference on Alzheimers Disease in Paris. The data from the openlabel trial are encouraging. Patients were able to tolerate bapineuzumab for two to four additional years without the emergence of any new safety concerns said Dr. Stephen Salloway author of one of the studies. This is important because we are conceptualizing this drug as a longterm treatment for Alzheimers disease. Encouraging does not translate into certainty however another expert pointed out. I think it is too early to tell from the data from this small Phase  safety trial said Ian Murray an assistant professor of neuroscience and experimental therapeutics at Texas AM Health Science Center College of Medicine in College Station. We will have to wait for larger trials to comment on this as a potential therapy. The studies were funded by Pfizer Inc. and Janssen Alzheimer Immunotherapy. Although bapineuzumab has shown promise in certain Alzheimers patients other research found that patients taking a higher dose of the drug had an increased risk of brain inflammation from water retention. This resulted in headache memory loss hallucinations reduced coordination or other symptoms. But no problems were seen with lower doses. Bapineuzumab is a humanized monoclonal antibody which binds to and might be able to eliminate beta amyloid peptide in the brains of people with Alzheimers. Most experts believe that the build up of beta amyloid proteins which accumulate as plaque is responsible for Alzheimers. Salloways study looked at the drugs safety in  Alzheimers patients most of whom had mild tomoderate Alzheimers and participated in a longterm  weeks or longer study. Some of the participants were followed for four years or more. Ninetyone percent of participants had side effects about a quarter of which were attributable to bapineuzumab. Of these  percent were mild or moderate.  The overall rate of vasogenic edema water on the brain was . percent a number that decreased over time said Salloway a professor of neurology and psychiatry at Alpert Medical School of Brown University and director of the Butler Hospital Memory and Aging Program in Providence R.I. The edema was symptomless in most cases he said. The other study which involved looking at more than  MRI scans from  patients found  cases of amyloidrelated imaging abnormalities ARIA may have been linked to the bapineuzumab.  These imaging abnormalities may indicate inflammation of the brain caused by water retention. But only  of those  cases involved symptoms and they were more likely to be found in patients with APOEe who were taking higher doses of the drug. The likelihood of these effects diminished with additional infusions of lowerdose bapineuzumab. There is a growing sense that VE vasogenic edema or ARIA amyloidrelated imaging abnormalities is a manageable side effect and may actually be a sign that the drug is clearing amyloid from the brain and the blood vessels said Salloway. Treatment will require ongoing monitoring with MRI. The researchers who said monitoring of bapineuzumab will continue are now awaiting the results of a larger Phase III trial on the drug. Because this study was presented at a medical meeting the data and conclusions should be viewed as preliminary until published in a peerreviewed journal. More information  The Alzheimers Association http has more on this condition.  SOURCES Stephen Salloway M.D. professor neurology and psychiatry Alpert Medical School of Brown University and director Butler Hospital Memory and Aging Program Providence R.I. Ian Murray Ph.D. assistant professor neuroscience and experimental therapeutics Texas AM Health Science Center College of Medicine College Station July   presentation Alzheimers Association International Conference on Alzheimers Disease Paris"