Alzheimer’s and Parkinson’s - new dawn or false hope?

This last week has seen what sound like very encouraging developments in potential treatments for both Alzheimer’s Disease and Parkinson’s. But when you or your family is affected by an incurable disease, you greet any news story about a possible cure with both great interest and extreme caution.

The news about Alzheimer’s was particularly dramatic. After years of failure, finally a drug has been discovered which can slow the disease. Lecanemab has apparently succeeded in a quest that researchers into neurodegenerative conditions like Alzheimer’s and Parkinson’s have pursued for years, finding a way to change what’s going on inside the brain. The drug seeks out and removes a protein known to build up in the brains of people with Alzheimer’s and trials showed it slowing memory decline by 27%.

Our family has, like many, been deeply affected by Alzheimer’s. The news about lecanemab came the day after the funeral of my wife’s sister, a quietly brilliant woman with an Oxford chemistry doctorate who spent a career involved in the regulation of new drugs. Her life was ended far too early by this cruel disease.

So the news of a drug which could slow Alzheimer’s - described as “momentous” by researchers - seemed like a big step forward. But I was cautious, remembering past stories in over-excited newspapers. “Alzheimer's cure at last: First drug to stop disease in its tracks” ran a 2016 headline on a Daily Express story about a repurposed diabetes drug called liraglutide.

Again, researchers appeared very positive - “if effective, there could be a potential new and safe treatment for Alzheimer’s in the next five years” said the academic running the trials. As we know, that has not happened, although repurposed diabetes drugs continue to be of great interest to researchers into both Alzheimer’s and Parkinson’s.

Now, lecanemab is much further down the road from the lab to the doctor’s prescription than liraglutide was in 2016. But there are still reasons to be cautious about this “miracle” drug and, to be fair, the experienced medical journalists covering the story did not ignore its limitations.

The BBC’s James Gallagher wrote that “lecanemab has only a small effect and its impact on people's daily lives is debated. And the drug works in the early stages of the disease, so most would miss out without a revolution in spotting it.”

So - great news that at last there is a drug which can affect the physiology of the brain but it is unlikely to make much difference to many patients in the short-term.  Rather its significance may be in guiding other researchers to focus their attention on this area and perhaps more importantly to encourage funders to support such efforts.

But what about the radical new treatment for Parkinson’s described in a story pointed out to me over the Sunday breakfast table by my wife? Again, this involves intervening directly in the brain, in this case by using stem cells grown in a Cambridge laboratory and implanting them to replace cells destroyed by the disease. In fact, I did know about this exciting new approach, partly funded by Cure Parkinson’s, and I hope to visit Professor Roger Barker in Cambridge soon to learn more about his research.

But the reason to be cautious in this case is the timescale involved. Getting a new drug or treatment through clinical trials and regulatory approval is a lengthy process, and with both Parkinson’s and Alzheimer’s that is compounded by the difficulty of measuring symptoms so that any improvement is detectable. The cell replacement technique is at an early stage of that process, so it will be some years before we know whether it works.

We are now in a really exciting era for research into Parkinson’s and Alzheimer’s and there is a feeling that a breakthrough is just over the horizon. But those affected by these conditions have learned to look beyond the headlines, read more widely and, above all, be patient.

This post is in memory of Dr Sue Chambers. Please donate to Alzheimer’s research.