Sunday, 6 November 2016

A Cure for Alzheimer's?

Alzheimer's is one of the most well-known neurodegenerative diseases. It is the most common form of Dementia, a type of brain disease that causes forgetfulness and a progressive loss in cognitive function. The proportion of people with Alzheimer's increases with age - the Alzheimer's Society estimate that there are over 850,000 people living with the disease in the UK. 

Like many diseases, Alzheimer's is multifactorial. This means that there is not a singular cause that results in a person suffering from the disease. In the case of Alzheimer's, there is a combination of factors that can contribute to the onset, such as genetics and age. There are also a multitude of hypotheses that attempt to explain why people contract the disease. 

Generally, it is understood that those with Alzheimer's have an abnormal amount of protein (specifically, amyloid plaques), fibres (tau tangles) and chemicals (acetylcholine) in the brain. The combination of these reduces the effectiveness of healthier brain nerves and gradually destroys them (hence why Alzheimer's is called a neurodegenerative disease – it worsens over time). Over progression of the disease, the damage can spread to areas of the brain such as the hippocampus and grey matter. These brain areas are responsible for memory and processing thoughts respectively, so it is understandable why some of the more common effects of Alzheimer's include forgetfulness and confusion. 

A brain slice showing amyloid plaque formations
Source: Jensflorian/Wikimedia Commons
We currently have an ageing population, which means that the issue of caring for those with the disease will only become larger. This means that research into new treatments or care programs are more important than ever. 

A new study published in Science Translational Medicine described some positive results. The team of researchers from Merck Research Laboratories developed a compound that was found to block the activity of an enzyme that is involved in Alzheimer's progression. The new drug compound, called verubecestat, works by blocking the BACE1 enzyme. This enzyme normally produces amyloid beta, a protein that clumps together and forms the amyloid plaques that are characteristic of Alzheimer's disease.

Attempting to block the BACE1 enzyme is not a new occurrence, however. Researchers have been trying to target BACE1's activity for many years, but previous attempts have resulted in study volunteers experiencing severe side effects. 

Blocking the BACE1 enzyme can help to halt the development of amyloid plaques. The amyloid hypothesis of Alzheimer's suggests that the accumulation of these amyloid plaques drives a cascade of various events within the brain that eventually lead to neurodegeneration. So, blocking BACE1 could have a real impact on the progression of Alzheimer's.
The molecular make up of verubecestat
Source: Kennedy et al, 2016, BACE1 inhibitor verubecestat (MK-8931) reduces CNS beta-amyloid in animal models and in Alzheimer's disease patients, Science Translational Medicine, p. 2.
This study is particularly exciting as it demonstrates the potential research now has - a few years ago these results would be impossible, as researchers were not able to successfully block BACE1. However, the study is only at clinical trial phase 1, which means verubecestat has just been trialled on a small group of healthy volunteers. The next step is to test on a small group of patients with Alzheimer's. If this is successful, the drug can be trialled on a large group of Alzheimer's patients, before approval for the wider public.

I also wonder how successful this drug will be considering that there is not yet a singular defined cause for Alzheimer's. If the drug is successful, it backs the amyloid hypothesis of Alzheimer's. However, other causes, such as a genetic disposition, can contribute to the onset. Is there a possibility that this new drug will work with varying levels of success for different cases?

What do you think about these new findings? Do you think a cure for Alzheimer's is a realistic possibility for the near future? Let me know in the comments!

If you would like to read the original study, please click here. For more general information about Alzheimer's from the Alzheimer's Society, please click here


3 comments:

  1. It's very promising indeed. But like other life changing diseases, lifestyle changes will be needed alongside medical help I think. Just like with heart disease etc.

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  2. I really didn't realise how many people in this country actually suffer from this tragic illness. I really hope progress can be made to help cure this. Well done for highlighting and raising awareness.

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    1. Thanks for your comment. I agree! The more we talk about it with others the more awareness we can raise :)

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