'De-Tangling' Alzheimer's Drug Shows Promise (HealthDay)

TUESDAY, July 29 (HealthDay News) -- A drug that aims to reducethe clogging "tangles" in the brain cells of people with Alzheimer'sdisease appears promising in early trials, researchers report.

Further studies are necessary to confirm whether the medication is aseffective at slowing Alzheimer's as it seems, or whether it needs to begiven as part of a cocktail of treatments.

Still, the new findings are promising, said study lead author Claude M.Wischik, professor in mental health at the University of Aberdeen in theU.K., and chairman of TauRx Therapeutics, which is testing the compound."The good news is that this is a breakthrough," he said. "A whole new,different approach has opened up against the odds, against people'sexpectations."

These and other findings into potential Alzheimer's treatments wereexpected to be released Tuesday at the Alzheimer's Association'sInternational Conference on Alzheimer's Disease, in Chicago.

At issue in the TauRx study are proteins in the brain known as tau. Ifthey work correctly, they act as the equivalent of rivets in the "railroadtracks" in brain cells, allowing communication between cells, Wischiksaid.

But in people with Alzheimer's disease, these proteins create untidymats of fibers called "tangles" in the brain. The tangles are directlylinked to dementia, while the effects of another factor in Alzheimer's -- bits of protein gunk called amyloid plaques -- are variable, he said.

"People could have lots of this stuff (amyloid) and still play lots ofbridge," Wischik said, "but if you have a lot of aggregated tau in thebrain, you can't find your way to the toilet."

The new study looked at a drug designed to reduce the number oftangles. The study was a Phase II trial, meaning it looked only atappropriate doses and effectiveness. A larger, Phase III trial -- the lastof the three routine phases of research into a drug -- is scheduled tobegin next year.

Researchers gave either the drug, known as MTC, or a placebo to 321Alzheimer's patients in the United Kingdom and in Singapore for 24weeks.

Wischik's group found that the drug stabilized the progression ofAlzheimer's over 50 weeks.

"The data show an 82 percent of reduction in the rate which the diseaseprogresses," Wischik said.

Dr. Sam Gandy, chairman of the Alzheimer's Association's NationalMedical and Scientific Advisory Council, said the new study results areindeed promising, and he added that another anti-tau treatment is in theworks.

"They could potentially be part of a cocktail of anti-amyloid andanti-tau drugs that might be the way we eventually come around to treatingAlzheimer's, trying to hit multiple steps (in disease formation)," hesaid. "This is the sort of approach that's been successful in treating HIVand cancer."

The finding comes on the heels of results from another tau-targetedAlzheimer's drug trial, released at the ICAD meeting Monday. In thatstudy, led by Dr. Donald Schmechel of Duke University Medical Center,older adults with what's known as mild cognitive impairment received anexperiment nasal spray peptide called AL-108.

Mild cognitive impairment is typically thought of as a potentialprecursor to Alzheimer's disease. In the Phase II study, patients whoreceived high doses of AL-108 over 12 weeks gained "statisticallysignificant, dose-dependent and durable improvement" in a variety ofmemory abilities, Schmechel said in an Alzheimer's Association newsrelease.

In other findings released at the meeting Tuesday:

Researchers released detailed results of a Phase III trial of the drugtarenflurbil (Flurizan), which was targeted at reducing the sticky amyloidplaques in the brain. In June, the drug's manufacturer, Myriad Genetics,announced that the agent had failed to effectively treat Alzheimer'sdisease. The company is no longer developing the drug for the treatment ofAlzheimer's.

According to the results of the trial, the drug did reduce plaques butwas still no better at helping patients with mild Alzheimer's than aplacebo, while causing more of some types of side effects.

On the other hand, a Phase II trial of a drug known as PBT2 did showsome promising results. According to researchers at the University ofCalifornia, Los Angeles, PBT2 is thought to reduce amyloid plaques bydisrupting the interaction of chemicals in the brain.

The trial, which was also published online Tuesday in The LancetNeurology, involved 78 people with mild Alzheimer's who got PBT2 or aplacebo daily for 12 weeks. The agent did reduce levels of amyloid plaquein cerebrospinal fluid. People on the higher dose (250 milligrams) of thedrug also showed significant improvements in certain mental tests comparedto those on placebo, the team reported.

Finally, a study from food company Danone suggests that a nutrient-rich"medical food" called Souvenaid could help boost the formation of brainsynapses and may reduce amyloid plaques in patients with mild Alzheimer's.The product contains nutrients such as choline and omega-3 fatty acids,thought to be conducive to brain health.

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