From USA Today
Alzheimer's researchers from Scotland announced on Tuesday that for the first time they have developed a drug that can halt cognitive decline in patients with mild and moderate Alzheimer's disease.
In the largest Phase II clinical trial
of its kind, study author Claude Wischik, professor at the University of Aberdeen in the U.K. and executive chairman of TauRx Therapeutics, said that TauRx's drug methylthioninium chloride (MTC) was successful at halting the symptoms of Alzheimer's disease over a 50-week period.
Previous research has shown that a buildup of abnormal nerve fibers in the brain, made up of a protein called tau, is linked to memory loss in Alzheimer's disease. Rember, the brand name of the drug, had been successful at melting tau tangles in lab tests and in animal studies, but this is the first time an anti-tau drug has demonstrated benefits in people with Alzheimer's disease.
In Wischik's study, 321 people with either mild or moderate Alzheimer's disease were given a placebo or one of three doses — 30, 60 or 100 milligrams — of MTC three times a day for up to 84 weeks. Imaging scans were taken at the beginning of the study and again at 24 weeks. Patients' cognitive abilities were measured at 24, 50 and 84 weeks.
At 24 weeks, there was a decline in disease progression in only the patients with moderate Alzheimer's who were taking 60-mg capsules. But by 50 weeks, patients with mild and moderate Alzheimer's taking the medium and highest doses of the drug also saw a benefit, according to the researchers.
Wischik says the drug appeared to be reasonably well tolerated.
But some of Wischik's peers say it's too early to make such claims.
Wischik says he is swimming against the research tide. "The main story in town for the last 20 years has been attacking amyloid plaque. A lot of people have said it's too late to treat the tangles, but that's bunkum," he says. Amyloid proteins form plaque outside brain cells, whereas tau proteins develop inside nerve cells.
A drug with multiple targets may be the answer, says Scott Turner, incoming director of the memory disorders program at Georgetown University Medical Center. "I think we may ultimately be treating with a drug cocktail that includes both anti-tau and anti-amyloid properties," he says.
And from Bloomberg
TauRx Alzheimer's Drug Slowed Patients' Decline for a Year
A chemical used to dye body parts for surgery, treat a blood disorder and clear fungal infections in fish may also be a new weapon against Alzheimer's, a study by a Singapore company suggests.
The compound, methylene blue, helped improve cognitive scores of Alzheimer's patients compared with a placebo, according to the study by the company, TauRx Therapeutics Ltd. The data was presented today in Chicago at the International Conference on Alzheimer's Disease.
TauRx's experimental drug, called Rember, is aimed at an abnormal version of a protein known as tau that's linked to Alzheimer's. When healthy, tau supplies nutrients to nerve cells in the brain. When damaged, it creates tangles that shut off nutrients. The treatment may offer an alternative to other experimental compounds that target beta amyloid, a more widely studied protein tied to Alzheimer's.
``You can have two patients with the same amounts of amyloid and one can play bridge and the other can't find the way to the toilet,'' said the lead author, Claude Wischik, who is chairman of TauRx and a professor at the University of Aberdeen, Scotland, last week in a telephone interview. ``What we're presenting is an alternative approach.''
Tau is tied to brain cell death, and may be more closely associated with dementia from Alzheimer's than beta amyloid, scientists said. Rember prevents the aggregation of tau proteins and dissolves the tau tangles, Wischik said.
The most common side effects in the study were diarrhea and discolored urine. Methylene blue has had many medical uses over the years, including killing bacteria in the urinary tract and as treatment for malaria and gonorrhea. The chemical is also being studied in bipolar disorder, according to Bloomberg data.
Alzheimer's will claim about 1 in 8 baby boomers, those born between 1946 and 1964, or about 10 million Americans.