A reader recently asked me about an experimental drug called Ibudilast.
It is a ‘Phosphodiesterase 4 inhibitor’.
Recently there was a very interesting result in a clinical trial looking at Ibudilast in a specific neurodegenerative condition. Sadly for the reader that condition was not Parkinson’s, in fact very little research has been done on Ibudilast in Parkinson’s
In today’s post we will look at what Phosphodiesterase inhibitors are, how they work, and discuss why Ibudilast may not be such a good experimental treatment for Parkinson’s.
On April 21-27th, 2018, the American Academy of Neurology (AAN) will hold their 70th Annual Meeting in Los Angeles (California).
I will not be at the meeting, but I will definitely be keeping an eye out for any news regarding the results of one particular clinical trial. At the meeting, a biopharmaceutical company called MediciNova Inc. will be presenting data regarding one of their clinical trials.
The presentation, entitled “Ibudilast – Phosphodiesterase Type 4 Inhibitor – Bi-Modal Therapy with Riluzole in Early Cohort and Advanced Amyotrophic Lateral Sclerosis (ALS) Patients – Final Report and Future Directions“ (Source) will be presented by principal investigator of the clinical study, Dr. Benjamin Rix Brooks, of the Carolinas HealthCare System’s Neuromuscular/ALS-MDA Center at Carolinas HealthCare System Neurosciences Institute.
Dr Brooks will be presenting the results of a single-center, randomized, double-blind, placebo-controlled clnical trial which was conducted to evaluate the safety, tolerability and clinical endpoint responsiveness of a drug called Ibudilast (or MN-166) in subjects with the neurodegenerative condition, Amyotrophic Lateral Sclerosis (or ALS – also known as motor neuron disease; Click here to read a previous SoPD post about ALS and Click here to learn more about this clinical trial).
What is Ibudilast?
Ibudilast is a phosphodiesterase inhibitor.
What is a phosphodiesterase inhibitor?
There has been a lot of discussion on this site (and elsewhere on the web) regarding the need for more objective systems of measuring Parkinson’s – particularly in the setting of clinical trials.
Yes, subjective reports of patient experience are important, but they can easily be biased by ‘placebo responses’.
Thus, measures that are beyond the clinical trial participants conscious control – and focused on biological outcomes – are needed.
In today’s post, we will consider one possible approach: Smart pills. We will discuss what they are, how they work, and how they could be applied to Parkinson’s research.
In order to encourage a growing discussion regarding objective measures of Parkinson’s (and to follow up on previous rants – Click here and here for examples), I have decided to regularly (once a month) highlight new technologies that could provide the sort of unbiased methods of data collection that are required for assessing whether a treatment is having an impact on Parkinson’s.
Today, we will look at smart pills.
What is a smart pill?
This is one of those posts (read: rants) where I want to put an idea out into the ether for someone to chew on. It starts with a very simple question:
Why is ‘the drug’ the focus of a clinical trial?
If our goal is to find beneficial therapies for people with Parkinson’s, then the way we currently clinically test drugs is utterly nonsensical.
And if we do not change our “we’ve always done it this way” mindset, then we are simply going to repeat the mistakes of the past. Others are changing, so why aren’t we?
In today’s post, we will consider one possible alternative approach.
Why is ‘the drug‘ the focus of a clinical trial?
The way we clinically test drugs makes absolutely no sense when you actually stop and think about it.
Other medical disciplines (such as oncology) have woken up to this fact, and it is time for the field of Parkinson’s research to do this same.
Let me explain:
My piece was called the Dilemma of Success, and it explored a hypothetical situation that we may very well face in the not-so-distant future.
Optimistic as I am about the future of Parkinson’s research, I think this is a very serious issue – one which the Parkinson’s community needs to discuss and start planning for. I am re-posting it here today as I am keen for some thoughts/discussion on this matter.
Lord Robert Baden-Powell. Source: Utahscouts
My scout master looked around the horse shoe, making eye contact with each of us, before asking a simple question:
“When did Noah build the ark?”
My fellow scouts and I looked at each other. Some of us were wondering if the guy had completely lost the plot and somehow thought that it was Sunday morning and he was doing the sermon. Others seriously looked like they were trying to calculate an exact date.
He waited a moment for one of us to offer up some idiotic attempt at an answer, before he solemnly said:
“Before the rain”
It’s one of those childhood moments that didn’t make sense at the time, but comes back to haunt you whenever you can foresee certain troubles coming over the hill towards you.
The dilemma of success
It will be nice to have this problem, but it will still be a problem.
And we need to plan for it
“Repurposing” in medicine refers to taking drugs that are already approved for the treatment of one condition and testing them to see if they are safe and effective in treating other diseases. Given that these clinically available drugs have already been shown to be safe in humans, repurposing represents a method of rapidly acquiring new potential therapeutics for a particular condition.
The antidepressant, Trazodone, has recently been proposed for repurposing to neurodegenerative conditions, such as Parkinson’s.
In today’s post we will look at what Trazodone is, why it is being considered for repurposing, and we will review the results of a new primate study that suggests it may not be ideal for the task.
Opinions. Everyone has them. Source: Creativereview
I am regularly asked by readers to give an opinion on specific drugs and supplements.
And I usually cut and paste in my standard response: I can not answer these sorts of questions as I am just a research scientist not a clinician; and even if I was a clinician, it would be unethical for me to comment as I have no idea of your medical history.
In many of these cases, there simply isn’t much proof that the drug/supplement has any effect in Parkinson’s, so it is hard to provide any kind of “opinion”. But even if there was proof, I don’t like to give opinions.
Eleven out of every ten opinions are usually wrong (except in the head of the beholder) so why would my opinion be any better? And each individual is so different, why would one particular drug/supplement work the same for everyone?
In offering an answer to “my opinion” questions, I prefer to stick to the “Just the facts, ma’am” approach and I focus solely on the research evidence that we have available (Useless pub quiz fact: this catchphrase “Just the facts, ma’am” is often credited to Detective Joe Friday from the TV series Dragnet, and yet he never actually said it during any episode! – Source).
Detective Joe Friday. Source: Wikipedia
Now, having said all of that, there is one drug in particularly that is a regular topic of inquiry (literally, not a week goes by without someone asking about): an antidepressant called Trazodone.
What is Trazodone?
In 2017, Parkinson’s UK – the largest charitable funder of Parkinson’s disease research in Europe – took a bold step forward in their efforts to find novel therapies.
In addition to funding a wide range of small and large academic research projects and supporting clinical trials, they have also decided to set up ‘virtual biotech’ companies – providing focused efforts to develop new drugs for Parkinson’s, targeting very specific therapeutic areas.
In today’s post we will look at the science behind their first virtual biotech company: Keapstone.
A virtual world of bioscience. Source: Cast-Pharma
I have previously discussed the fantastic Parkinson’s-related research being conducted at Sheffield University (Click here to read that post). Particularly at the Sheffield Institute for Translational Neuroscience (SITraN) which was opened in 2010 by Her Majesty The Queen. It is the first European Institute purpose-built and dedicated to basic and clinical research into Motor Neuron Disease as well as other neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease.
The research being conducted at the SITraN has given rise to multiple lines of research following up interesting drug candidates which are gradually being taken to the clinic for various conditions, including Parkinson’s.
It’s all very impressive.
And apparently I’m not the only one who thought it was impressive.
Mitochondrial division inhibitor-1 (mdivi-1) is a small molecule drug that is demonstrating very impressive effects in preclinical models of Parkinson’s disease. With further research it could represent a potential future therapy for people with Parkinson’s disease, particularly those with genetic mutations affecting the mitochondria in their cells.
What are mitochondria?
In this post, we will explain what mitochondria are, how they may be involved in Parkinson’s disease, and we will discuss what the results of new research mean for future therapeutic strategies.
Mitochondria are fascinating.
Utterly. Utterly. Fascinating.
On the most basic level, Mitochondria (mitochondrion, singular; from the Greek words mitos (thread) and chondros (granule)) are just tiny little bean-shaped structures within the cells in our body, and their primary function is to act as the power stations. They supply the bulk of energy that cells require to keep the lights on. This chemical form of energy produced by the mitochondria is called adenosine triphosphate (or ATP). Lots of mitochondria are required in each cell to help keep the cell alive (as is shown in the image below, which is showing just the mitochondria (red) and the nucleus (blue) of several cells).
Lots of mitochondria (red) inside cells (nucleus in blue). Source: Clonetech
That’s the basic stuff – the general definition you will find in most text books on biology.
But let me ask you this:
How on earth did mitochondria come to be inside each cell and playing such a fundamental role?
I don’t know. Are you going to tell me?
Because we simply don’t know.
But understand this: Mitochondria are intruders.
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:
In October 2015, researchers from Georgetown University announced the results of a small clinical trial that got the Parkinson’s community very excited. The study involved a cancer drug called Nilotinib, and the results were rather spectacular.
What happened next, however, was a bizarre sequence of disagreements over exactly what should happen next and who should be taking the drug forward. This caused delays to subsequent clinical trials and confusion for the entire Parkinson’s community who were so keenly awaiting fresh news about the drug.
Earlier this year, Georgetown University announced their own follow up phase II clinical trial and this week a second phase II clinical trial funded by a group led by the Michael J Fox foundation was initiated.
In todays post we will look at what Nilotinib is, how it apparently works for Parkinson’s disease, what is planned with the new trial, and how it differs from the ongoing Georgetown Phase II trial.
The FDA. Source: Vaporb2b
This week the U.S. Food and Drug Administration (FDA) has given approval for a multi-centre, double-blind, randomised, placebo-controlled Phase IIa clinical trial to be conducted, testing the safety and tolerability of Nilotinib (Tasigna) in Parkinson’s disease.
This is exciting and welcomed news.
What is Nilotinib?
Nilotinib (pronounced ‘nil-ot-in-ib’ and also known by its brand name Tasigna) is a small-molecule tyrosine kinase inhibitor, that has been approved for the treatment of imatinib-resistant chronic myelogenous leukemia (CML).
What does any that mean?
Basically, it is the drug that is used to treat a type of blood cancer (leukemia) when the other drugs have failed. It was approved for treating this cancer by the FDA in 2007.
The contents of today’s post may not be appropriate for all readers. An illegal and potentially damaging drug is discussed. Please proceed with caution.
3,4-Methylenedioxymethamphetamine (or MDMA) is more commonly known as Ecstasy, ‘Molly’ or simply ‘E’. It is a controlled Class A, synthetic, psychoactive drug that was very popular with the New York and London club scene of the 1980-90s.
It is chemically similar to both stimulants and hallucinogens, producing a feeling of increased energy, pleasure, emotional warmth, but also distorted sensory perception.
Another curious effect of the drug: it has the ability to reduce dyskinesias – the involuntary movements associated with long-term Levodopa treatment.
In today’s post, we will (try not to get ourselves into trouble by) discussing the biology of MDMA, the research that has been done on it with regards to Parkinson’s disease, and what that may tell us about dyskinesias.
Good times. Source: Carwash
You may have heard this story before.
It is about a stuntman.
His name is Tim Lawrence, and in 1994 – at 34 years of age – he was diagnosed with Parkinson’s disease.
Tim Lawrence. Source: BBC
Following the diagnosis, Tim was placed on the standard treatment for Parkinson’s disease: Levodopa. But after just a few years of taking this treatment, he began to develop dyskinesias.
Dyskinesias are involuntary movements that can develop after regular long-term use of Levodopa. There are currently few clinically approved medications for treating this debilitating side effect of Levodopa treatment. I have previously discussed dyskinesias (Click here and here for more of an explanation about them).
As his dyskinesias progressively got worse, Tim was offered and turned down deep brain stimulation as a treatment option. But by 1997, Tim says that he spent most of his waking hours with “twitching, spasmodic, involuntary, sometimes violent movements of the body’s muscles, over which the brain has absolutely no control“.
And the dyskinesias continued to get worse…
…until one night while he was out at a night club, something amazing happened:
“Standing in the club with thumping music claiming the air, I was suddenly aware that I was totally still. I felt and looked completely normal. No big deal for you, perhaps, but, for me, it was a revelation” he said.
His dyskinesias had stopped.