Here at the SoPD, we are primarily interested in disease modification for Parkinson’s. While there is a great deal of interesting research exploring the causes of the condition, novel symptomatic therapies, and other aspects of Parkinson’s, my focus is generally on the science seeking to slow, stop or reverse the condition.
At the start of each year, it is a useful practise to layout what is planned and what we will be looking for over the next 12 months. Obviously, where 2020 will actually end is unpredictable, but an outline of what is scheduled over the next year will hopefully provide us with a useful resource for better managing expectations.
In this post, I will try to lay out some of what 2020 holds for us with regards to clinical research focused on disease modification for Parkinson’s.
Lord Robert Baden-Powell. Source: Utahscouts
My old scout master once looked around our horse shoe, making eye contact with each of us, before asking the question:
“When did Noah build the ark?”
My fellow scouts and I looked at each other – confused. Did he want an exact date?!?
The scout master waited a moment for one of us to offer up some idiotic attempt at an answer – thankfully no one did – before he solemnly said:
“Before the rain”
It was one of those childhood moments that made little sense at the time, but comes back to haunt you as an adult when you are looking at what the future may hold and trying to plan for it.
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Today’s post is our annual horizon scanning effort, where we lay out what is on the cards for the next 12 months with regards to clinical research focused on disease modification in Parkinson’s.
We will also briefly mention other bits and pieces of preclinical work that we are keeping an eye on for any news of development.
To be clear, this post is NOT intended to be an exercise in the reading of tea leaves – no predictions will be made here. Nor is this a definitive or exhaustive guide of what the next year holds for disease modification research (if you see anything important that I have missed – please contact me). And it should certainly not be assumed that any of the treatments mentioned below are going to be silver bullets or magical elixirs that are going to “cure” the condition.
In the introduction to last year’s outlook, I wrote of the dangers of having expectations (Click here to read that post). I am not going to repeat that intro here, but that the same message applies as we look ahead to what 2020 holds.
In fact, it probably applies even more for 2020, than it did for 2019.
2020 is going to be a busy year for Parkinson’s research, and I am genuinely concerned that posts like this are only going to raise expectations. My hope is that a better understanding of where things currently are and what is scheduled for the next 12 months will help in better managing those expectations. Please understand that there is still a long way to go for all of these experimental therapies.
All of that said, let’s begin:
Things were a bit quiet on the SoPD over the summer, but for good reasons. There was a short hiatus for a family break, but the rest of the time I was rather occupied with the day job. Tremendous efforts were being made at the Cure Parkinson’s Trust, as we were gearing up for our main event of the year: the Linked Clinical Trials (LCT) meeting.
This is an annual meeting at which 20 Parkinson’s experts from around the world, gather for a two day face-to-face pow-wow. They evaluate dossiers which contain everything we know about 20+ compounds which have exhibited potential for disease modification in Parkinson’s. The goal of the committee is to decide which of them is ready for clinical evaluation.
The writing of those LCT dossiers is a year long exercise, which inevitably becomes a bit of a panic in June and July (hence the lack of activity here at SoPD HQ during that period). It is a mammoth, marathon task, but as you shall see it is one that I rather like.
In today’s post, we will discuss what the Linked Clinical Trials initiative is, the process behind the project, and some of the progress being made by the programme.
Archimedes. Source: Lecturesbureau
Archimedes of Syracuse (287 BC – 212 BC) the ancient Greek mathematician, once said that the “shortest distance between two points is a straight line“.
My dad (who is not a regular readers of this blog, but is possibly on par with Archie – just in case he does ever read this) has often been heard saying “Just get to the point Simon“.
Millennia apart, but their collective wisdom is same: Ignore everything else, and get straight to the heart of the matter as quickly as you can.
And this is one of the aspect I really like about the Linked Clinical Trials initiative.
It is all about getting to potentially disease modifying treatments for Parkinson’s to the community as quickly as possible.
What is the Linked Clinical Trials programme?
Dipeptidyl peptidase-4 (or DPP-4) is an enzyme that breaks down the protein (GLP-1) that stimulates insulin release in your body.
Inhibitors of DPP-4 are used in the treatment of Type 2 diabetes, because they help increase insulin levels in the body.
Recently some Swedish researchers noticed something curious about DPP-4 inhibitors: They appear to reduce the risk of developing Parkinson’s disease.
In today’s post, we will review what DPP-4 inhibitors do and look at how this could be reducing the risk of Parkinson’s disease.
Sitagliptin. Source: Diabetesmedicine
Last year an interesting research report about a class of medications that could possibly reduce the risk of developing Parkinson’s disease was published in the journal Movement disorders:
Title: Reduced incidence of Parkinson’s disease after dipeptidyl peptidase-4 inhibitors-A nationwide case-control study.
Authors: Svenningsson P, Wirdefeldt K, Yin L, Fang F, Markaki I, Efendic S, Ludvigsson JF.
Journal: Movement Disorders 2016 Jul 19.
In this study, the investigators used the Swedish Patient Register, to find the medical records of 980 people who were diagnosed with Parkinson’s disease but also had type 2 diabetes. Importantly, all of the subjects had been treated with Type 2 diabetes medication for at least 6 months prior to the date of Parkinson’s being diagnosed.
For comparative sake, they selected 5 controls (non-Parkinsonian) with Type 2 diabetes (n = 4,900) for each of their Parkinsonian+diabetes subjects. They next looked at whether GLP-1R agonists (such as Exenatide), Dipeptidyl peptidase-4 (or DPP-4) inhibitors, or any other oral Type 2 diabetic medication can influence the incidence of Parkinson’s disease.
Now, if all things are considered equal, then when looking at each diabetes medication there should be 1 person in the Parkinson’s disease + Type 2 diabetes for every 5 people in the Type 2 diabetes control group taking each medication right? That is because there are almost 1000 people in the first group and 5000 in the second group.
But this is not what the researchers found.
In my previous post, we briefly reviewed the results of the phase II double-blind, randomised clinical trial of Exenatide in Parkinson’s disease. The study indicates a statistically significant effect on motor symptom scores after being treated with the drug.
Over the last few days, there have been many discussions about the results, what they mean for the Parkinson’s community, and where things go from here, which have led to further questions.
In this post I would like to address several matters that have arisen which I did not discuss in the previous post, but that I believe are important.
I found out about the Exenatide announcement – via whispers online – on the afternoon of the release. And it was in a mad rush when I got home that night that I wrote up the post explaining what Exenatide is. I published the post the following evening however because I could not access the research report from home (seriously guys, biggest finding in a long time and it’s not OPEN ACCESS?!?!?) and I had to wait until I got to work the next day to actually view the publication.
I was not really happy with the rushed effort though and decided to follow up that post. In addition, there has been A LOT of discussion about the results over the weekend and I thought it might be good to bring aspects of those different discussion together here. The individual topics are listed below, in no particular order of importance:
1. Size of the effect
There are two considerations here.
Firstly, there have been many comments about the actual size of the effect in the results of the study itself. When people have taken a deeper look at the findings, they have come back with questions regarding those findings.
And second, there have also been some comments about the size of the effect that this result has already had on the Parkinson’s community, which has been considerable (and possibly disproportionate to the actual result).
The size of the effect in the results
The results of the study suggested that Exenatide had a positive effect on the motor-related symptoms of Parkinson’s over the course of the 60 week trial. This is what the published report says, it is also what all of the media headlines have said, and it sounds really great right?
The main point folks keep raising, however, is that the actual size of the positive effect is limited to just the motor features of Parkinson’s disease. If one ignores the Unified Parkinson’s Disease Rating Scale (UPDRS) motor scores and focuses on the secondary measures, there isn’t much to talk about. In fact, there were no statistically significant differences in any of the secondary outcome measures. These included: