Promising New Drug Development Announced at Alzheimer’s Conference

Author: Madeline Ellis

The 2008 International Conference on Alzheimer's Disease (ICAD) is taking place this week, July 26-31, at McCormick Place in Chicago. More than 5,000 world-renowned researchers from 60 countries were expected to be on hand for what is considered the world's largest gathering of international leaders in Alzheimer research and care ever convened. Through the sharing of information and resources on the cause, diagnosis, treatment and prevention of Alzheimer's and related disorders, new knowledge is generated and the research community is broadened.

While many research findings have been presented thus far, one in particular seems to have taken center stage. A new drug, known as Rember, has been shown to stop the progression of Alzheimer's by as much as 81 percent, according to a Phase II study. The drug works by not only dissolving the tangle of tau fibers, which release waste products that kill nerve cells, but also prevents the formation of new tangles. Previous research has shown that the buildup of brain lesions known as neurofibrillary tangles, which are composed of a short fragment of a protein called tau, is correlated with increasing levels of dementia symptoms. "We have demonstrated for the first time that it may be possible to arrest progression of the disease by targeting the tangles that are highly correlated with the disease," said Dr. Claude Wischik, lead researcher and co-founder of TauRX Therapeutics, which is developing the treatment. "This is the most significant development in the treatment of the tangles since Alois Alzheimer discovered them in 1907."

The research involved 321 people with mild and moderate Alzheimer's disease in 17 centers in the United Kingdom and Singapore. The participants were divided into four groups; three taking different doses (30, 60, and 100 mg three times per day) of Rember and the fourth group taking a placebo. After 50 weeks, those taking the drug experienced 81 percent less mental decline than those taking the placebo. Also, over a 19-month period, those taking Rember showed no significant decline in their mental function compared to the placebo group who got worse. Dr. Donald Mowat, consultant psychiatrist who monitored the progress of the patients, said those taking Rember were more confident, better able to cope with daily life and were not experiencing the level of mental decline they had expected.

Brain imaging using SPECT and PET showed the most significant effect in the parts of the brain linked to memory, namely the hippocampus and the entorhinal cortex, where the density of tau tangles is greatest. "This is an unprecedented result in the treatment of Alzheimer's disease," said Professor Wischik. "We appear to be bringing the worst affected parts of the brain functionally back to life."

The trail results suggest rember is about two-and-a-half times more effective than existing Alzheimer's drugs called cholinesterase inhibitors. The next step is to confirm the results in a larger Phase III trial, which is due next year. Professor Stephen Logan, professor of neuroscience and TauRX board member, says that if the Phase III trial is successful, the drug could be on the market by 2012. "This is a fantastic breakthrough and very exciting," he said.

The researchers are also working on scanning techniques to diagnose Alzheimer's at its earliest stages when the tau tangles are first being formed in the brain and hope that rember will eventually be used as a preventative treatment. However, Professor Logan says "this would take much longer to perfect." He also said the cost of the treatment is unknown but would need to be compared with the expense of caring for Alzheimer's patients both in the community and in the hospital.