Posted for Tim Sands
There has been news this week of two new drugs that could slow the progression of Alzheimer’s disease. Both studies were announced at the Alzheimer’s Association International Conference on Alzheimer’s Disease in Chicago. The drugs target different proteins that underlie the degenerative symptoms of the disease.
The first team from Aberdeen University in the UK and Aberdeen spin-out company TauRX Therapeutics based in Singapore, unveiled the drug called Rember that dissolves the bundles of tau protein fibres that cause brain cell death, leading to the disease symptoms.
The drug is based on the chemical methylthioninium chloride, better known as the commonplace lab dye, methylene blue, and the BBC reports that the effect of the drug on tau was discovered 20 years ago by lead researcher Claude Wischik in a lab accident. If so, the accident was a happy one as the phase II clinical trial on 321 patients showed that patients treated with the drug did not show any significant decline in cognitive function over the course of 19 months, while patients without the drug showed a marked decline.
“This first modestly sized trial in humans is potentially exciting,” says Clive Ballard, director of research at the Alzheimer’s Society. “It suggests the drug could be over twice as effective as any treatment that is currently available. However we are not there yet. Larger scale trials are now needed to confirm the safety of this drug and establish how far it could benefit the thousands of people living with this devastating disease.”
A second study announced at the conference, and published online in Lancet Neurology this month, also reveals the results of phase II trials of another drug, called PBT2. This works by counteracting the accumulation of the protein amyloid-beta that can build up to form devastating plaques in the brain.
Those patients on the highest dosage of the drug for the 12 week duration of the 78-patient strong study performed significantly better than controls in tests of cognitive function but unfortunately not in memory tests. The researchers suspect this may be because memory declines more slowly than cognitive function so any improvements may not have been picked up by the study.
Further trials for both drugs are still pending, with phase III trials for Rember due to begin next year, so we will have to wait a few more years to know if these are bound for the pharmacy shelves.