At last: Selnoflast

December 15, 2022April 9, 2023 ~ Simon ~ 10 Comments

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One of the most common questions I get from SoPD readers is what’s new with inflammasome research? Another version of this question is where are the clinical trials for NLRP3 inhibitors in Parkinson’s?

Readers have become very enchanted by this new class of anti-inflammatory drugs as a potential future treatment for Parkinson’s – and there is preclinical evidence to support this vibe. But the clinical development of these experimental therapies has been slow.

Recently, the pharmaceutical company Roche has initiated Phase 1b testing of their NLRP3 inhibitor (called Selnoflast) in people with Parkinson’s – the first in this class.

In today’s post, we will discuss what the inflammasome is, how NLRP3 inhibitors work, and what the new clinical trial involves.

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On the 21st September 2020, the website for an Ireland-based biotech company called Inflazome suddenly disappeared. In its place was a single page, that stated the large pharmaceutical company Roche had purchased the biotech firm and taken on all of its inflammasome-targeting intellectual property (Source).

This was a big deal for folks who were watching the inflammasome research world. It suggested that the big players (pharma) were now interested in this space ($449 million interested in the case of Inflazome). And since then, there has been a rush of other pharma companies buying or developing inflammasome-targeting agents.

The Inflazome purchase was also interesting because the company was targeting Parkinson’s as one of their indications of interest.

And it would appear that Roche is now following up on this interest, having initiated a clinical trial program focused on inflammasomes in Parkinson’s.

Hang on a second. Remind me, what are inflammasomes?

Continue reading “At last: Selnoflast” →

Novartis focuses on improving PARKIN control

December 27, 2017December 28, 2017 ~ Simon ~ 8 Comments

Last week, as everyone was preparing for Christmas celebrations, researchers at the pharmaceutic company Novartis published new research on a gene that is involved with Parkinson’s, called PARKIN (or PARK2).

They used a new gene editing technology – called CRISPR – to conduct a large screening study to identify proteins that are involved with the activation of PARKIN.

In today’s post we will look at what PARKIN does, review the research report, and discuss how these results could be very beneficial for the Parkinson’s community.

Source: Novartis

As many people within the Parkinson’s community will be aware, 2017 represented the 200th anniversary of the first report of Parkinson’s disease by James Parkinson.

It also the 20th anniversary of the discovery of first genetic mutation (or variant) that increases the risk of developing Parkinson’s. That genetic variation occurs in a region of DNA (a gene) called ‘alpha synuclein’. Yes, that same alpha synuclein that seems to play such a critical role in Parkinson’s (Click here to read more about the 20th anniversary).

In 2018, we will be observing the 20th anniversary of the second genetic variation associated with Parkinson.

That gene is called PARKIN:

Title: Mutations in the parkin gene cause autosomal recessive juvenile parkinsonism.
Authors: Kitada T, Asakawa S, Hattori N, Matsumine H, Yamamura Y, Minoshima S, Yokochi M, Mizuno Y, Shimizu N
Journal: Nature. 1998 Apr 9; 392(6676):605-8
PMID: 9560156

In 1998, Japanese researchers published this report based on 5 individuals from 4 Japanese families who were affected by juvenile-onset Parkinson’s. In family 1, the affected individual was a female, 43 years old, born of first-cousin parents, and her two younger brothers are healthy. Her condition was diagnosed in her teens and it had then progressed very slowly afterwards. Her response to L-dopa was very positive, but L-dopa-induced dyskinesia were frequent. In family 2-4, affected individuals (born to unrelated parents) exhibited very similar clinical features to the subject in family 1. The age of onset was between 18 to 27 years of age.

Using previous research and various techniques the investigators were able to isolate genetic variations that were shared between the 5 affected individuals. They ultimately narrowed down their search to a section of DNA containing 2,960 base pairs, which encoded a protein of 465 amino acids.

They decided to call that protein PARKIN.

PARKIN Protein. Source: Wikipedia

How much of Parkinson’s is genetic?

Continue reading “Novartis focuses on improving PARKIN control” →

Nilotinib: the other phase II trial

July 31, 2017July 31, 2017 ~ Simon ~ 12 Comments

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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.

FDA-deeming-regulations

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?

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.

Continue reading “Nilotinib: the other phase II trial” →

An interesting commentary on the interpretation of the Nilotinib trial results

January 9, 2017January 10, 2017 ~ Simon ~ 2 Comments

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“The devil is in the detail”

A frequently used quote and sage words when analysing scientific data, especially clinical trial data.

Nilotinib is a cancer drug from Novartis that has the Parkinson’s community very excited. In October 2015, researchers at Georgetown University announced that a phase 1 open-label clinical study involving 12 people with Parkinson’s had demonstrated some pretty impressive results (click here to read more about this). The results of that first clinical trial have been published (click here to read more on this), but follow up studies have been hampered by study design issues (click here for more on this).

Today a letter to the editor of the Journal of Parkinson’s disease (published in this months issue) was brought to our attention (click here to read the letter). It queries one important aspect of the results from that first Nilotinib clinical trial for Parkinson’s disease.

In the letter, Prof Michael Schwarzschild of Massachusetts General Hospital (Boston) notes that 8 of the 11 subjects in the study had their monoamine oxidase-B (MAO-B) inhibitor treatment withdrawn less than a month after starting the trial. The change of treatment regime was made due to “increased psychosis in the first 2–4 weeks after Nilotinib administration”.

For reasons which we will outline below, a small change like this in a clinical trial could have major implications for the end results.

What are MAO-B inhibitors?

After the chemical dopamine is used by a neuron, it is reabsorbed by the dopamine cell and broken down for disposal. MAO-B is the enzyme that breaks down dopamine.

Selegiline is an example of a MAO-B inhibitor. Source: KnowMental

As the schematic above illustrates, dopamine is released by dopamine neurons and then binds to a receptor on a neighbouring cell. After this process has occurred, the dopamine detaches and it is reabsorbed by the dopamine neuron via a particular pathway called the dopamine transporter. Back inside the dopamine cell, dopamine is quickly broken down by the enzyme MAO-B into 3,4-Dihydroxyphenylacetic acid (or DOPAC).

Now, by blocking MAO-B, more dopamine is left hanging around inside the cell where it can be recycled and used again. Thus, this blockade increases the level of dopamine in the brain, which helps with alleviating the motor features of Parkinson’s disease. This simple concept has lead to the development of MAO-B inhibitors which are used in the treatment of the condition.

Why is this important to the Nilotinib results?

Dopamine is broken down by MAO-B into DOPAC. DOPAC can be further broken down into Homovanillic acid (HVA), and both DOPAC and HVA are often used in research studies to indicate levels of dopamine activity. Higher levels of both (in theory) should indicate higher levels of dopamine. It is a means of inferring greater dopamine production.

In the published results of the Nilotinib clinical trial, the researchers used increased HVA levels as an indication of greater dopamine production as a result of taking Nilotinib. But Prof Schwarzschild is correct in providing a cautionary warning of over-interpreting this result. You see, by discontinuing the treatment of MAO-B inhibitors shortly after starting the study, one would expect to see a rise in HVA levels regardless of any effect Nilotinib may be having. Without the MAO-B inhibitors, more dopamine will be broken down thus resulting in increased levels of HVA (compared to the baseline measurements at the start of the study).

And this issue is particularly important since HVA measurements taken at the start of the study (before the MAO-B inhibitors were removed) were compared with HVA measurement taken at the end of the study.

Another commentary discussing the Nilotinib results published in July of last year (in the same journal) actually questioned the value of measuring HVA levels, saying that prior studies have suggested that HVA levels can vary greatly between subjects at similar disease stages, and in general do not correlate well with disease progression.

Whether the removal of MAO-B inhibitors alters the overall interpretation of the first clinical study results is a subject for debate. Something interesting did appear to be happening in the participants involved in the first trial (whether this could have been a placebo effect could also be debated). Obviously, as Prof Schwarzschild’s letter indicates, what we really require now is a carefully designed, placebo-controlled, randomised clinical trial to determine if the initial results can be replicated.

And we are still awaiting news regarding a start date for that delayed trial.

Nilotinib update – new trial delayed

August 30, 2016August 30, 2016 ~ Simon ~ 3 Comments

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It is with great frustration that we read today of the delayed start to the phase 2 clinical trial of the re-purposed cancer drug Nilotinib for Parkinson’s disease (click here for a story outlining the background, and click here for the Michael J Fox Foundation statement).

We have previously discussed both the preclinical and clinical research regarding Nilotinib and its use in Parkinson’s disease (click here and here for those posts). And the Parkinson’s community certainly got very excited about the findings of the small phase 1 unblinded clinical trial conducted by researchers at Georgetown University in 2015.

With the recent failure of the GDNF trial in Bristol, what the Parkinson’s community (both suffers and researchers alike) needs to do is refocus on moving ahead with exciting new projects, like Nilotinib. To hear that the follow-up trials for Nilotinib, however, will be delayed until 2017 (TWO YEARS after the initial results were announced) due to disagreements regarding the design of the study and who is seemingly in charge of the project, is both baffling and deeply disappointing.

Currently it appears that parties involved in the follow-up clinical trial have decided to go their separate ways, with the researchers at Georgetown University looking to conduct a single site phase 2 study of 75 subjects (if they can access the drug from supplier Novartis), while the Michael J Fox backed consortium will set up a multi-site phase 2 study.

We will continue to follow this situation as it develops and will report events as they happen.

Nilotinib and Parkinson’s disease – an update

July 12, 2016January 9, 2017 ~ Simon ~ 4 Comments

We have previously discussed news briefings regarding a cancer drug that displayed interesting results in a pilot clinical study of Parkinson’s disease (click here to read that post). Today we will delve more deeply into the results of that particular study and consider what they mean.

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Nilotinib (Tasigna) from Novartis. Source: William-Jon

In October of last year, at the Society for Neuroscience meeting in Chicago, a presentation of data from a clinical trial got the Parkinson’s community really excited. The study was investigating the effects of a cancer drug called ‘Nilotinib’ (also known as Tasigna) on Parkinson’s disease and the initial results were rather interesting.

The results of the pilot clinical study for Nilotinib were published today in the Journal of Parkinson’s disease:

Nilo-title

Title: Nilotinib Effects in Parkinson’s disease and Dementia with Lewy bodies
Authors: Pagan F, Hebron M, Valadez E, Tores-Yaghi Y,Huang X, Mills R, Wilmarth B, Howard H, Dunn C, Carlson A, Lawler A, Rogers S, Falconer R, Ahn J, Li Z, & Moussa C.
Journal: Journal of Parkinson’s Disease, vol. Preprint
PMID: Yet to be allocated (This article is OPEN ACCESS if you would like to read it).

The study was setup to determine safety of using Nilotinib in Parkinson’s disease dementia or dementia with Lewy bodies.

What is Nilotinib?

Nilotinib is a drug that can be used to treat a type of leukemia when the other cancer drugs have failed. It was approved for this treating cancer by the FDA in 2007.

The researchers behind the current study believe that Nilotinib works by turning on autophagy – the “garbage disposal machinery” inside brain cells. Autophagy is a process that clears waste and toxic proteins from inside cells, preventing them from accumulating and possibly causing the death of the cell.

The process of autophagy – Source: Wormbook

Waste material inside a cell is collected in membranes that form sacs (called vesicles). These vesicles then bind to another sac (called a lysosome) which contains enzymes that will breakdown and degrade the waste material.

The researchers suggest that Nilotinib may be working in Parkinson’s disease by helping affected cells to better clear away the build up of unnecessary proteins, which helps cells to function more efficiently.

What happened in the clinical study?

Twelve people with either Parkinson’s disease dementia or dementia with Lewy bodies were randomized given either 150 mg (n = 5) or 300 mg (n = 7) daily doses of Nilotinib for 24 weeks. After the treatment period the subjects were followed up for 12 weeks. All of the subjects were considered to have mid to late stage Parkinson’s features (Hoehn and Yahr stage 3–5). One subject was withdrawn from the study at week 4 due to a heart attack and another discontinued at 5 months due to unrelated circumstances.

An important question in the study was whether Nilotinib could actually enter the brain. Various tests conducted on the subjects suggesting that the drug had no problem crossing the ‘blood brain barrier‘ and having an effect in the brain. The levels of Nilotinib in the brain peaked at 2 hrs after taking the drug and the levels of the target protein (called p-Abl) were reduced by 30% at 1 hr. This level of activity remained stable for several hours.

The motor features of Parkinson’s disease were assessed using the Unified Parkinson’s Disease Rating Scale (UPDRS) and the investigators observed an average decrease of 3.4 points and 3.6 points at six months (week 24) compared to the baseline measures (scores from the start of the study) with 150 mg and 300 mg Nilotinib, respectively. A decrease in motor scores represent a reduction in Parkinson’s motor features.

The really remarkable result, however, comes from the testing of cognitive performance, which was monitored with Mini Mental Status Examination (MMSE). The researchers report an average increase of 3.85 and 3.5 points in MMSE at six months (24-week) compared to baseline, for 150 mg and 300 mg of Nilotinib, respectively. This means that the mental processing of the subjects improved across the study.

The motor and cognitive results were complemented by measures of proteins in blood and cerebrospinal fluid samples taken from the subjects. The researchers saw increases in dopamine related proteins (suggesting that more dopamine was present in the brain) and stabilization of alpha synuclein levels.

The researchers concluded that these observations warrant a larger randomized, double-blind, placebo-controlled trial to truly evaluate the safety and efficacy of Nilotinib.

Here at the SoPD, we are inclined to agree.

So what does all this mean?

The results of the study are very interesting, and the researchers should be congratulated on the outcome (and presentation of all the data in the report). As they themselves acknowledge, the study was open labelled – meaning that everyone in the study knew that they were getting the treatment – so the placebo effect could be at play here.

One intriguing note in the report was that most of the participants in the study ‘experienced increased psychotic symptoms (hallucination, paranoia, agitation) and some dyskinesia whilst on Nilotinib’ suggesting an increase in dopamine levels in the brain.

Obviously a larger, double-blind study is required to determine whether the effect of the drug in Parkinson’s disease is real. The Michael J. Fox Foundation, the Van Andel Research Institute (Michigan, USA) and the Cure Parkinson’s Trust are collaborating on the development program for a double-blind, placebo-controlled clinical trial of nilotinib, which it is hoped will begin in 2017.

The banner for today’s banner was sourced from Wikimedia

Parkinson’s disease and the cancer drug

December 11, 2015September 2, 2017 ~ Simon ~ 7 Comments

In October, 40,000 neuroscientists from all over the world gathered in Chicago for the annual Society for Neuroscience conference. It is one of the premier events on the ‘brain science’ calendar each year and only a few cities in the USA have the facilities to handle such a huge event.

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Science conference. Source: JPL

During the five day neuroscience marathon, hundreds of lecture presentations were made and thousands of research poster were exhibited. Many new and exciting findings were presented to the world for the first time, including the results of an interesting pilot study that has left everyone in the Parkinson’s research community very excited, but also scratching their heads.

The study (see the abstract here) was a small clinical trial (12 subjects; 6 month study) that was aiming to determine the safety and efficacy of a cancer drug, Nilotinib (Tasigna® by Novartis), in advanced Parkinson’s Disease and Lewy body dementia patients. In addition to checking the safety of the drug, the researchers also tested cognition, motor skills and non-motor function in these patients and found 10 of the 12 patients reported meaningful clinical improvements.

The study investigators reported that one individual who had been confined to a wheelchair was able to walk again; while three others who could not talk before the study began were able to hold conversations. They suggested that participants who were still in the early stages of the disease responded best, as did those who had been diagnosed with Lewy body dementia.

So 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). That is to say, it is a drug that can be used to treat a type of leukemia when the other drugs have failed. It was approved for this treating cancer by the FDA in 2007.

The researchers behind the study suggest that Nilotinib works by turning on autophagy – the “garbage disposal machinery” inside each neuron. Autophagy is a process that clears waste and toxic proteins from inside cells, preventing them from accumulating and possibly causing the death of the cell.

The process of autophagy – Source: Wormbook

Some details about the study:

The study was run at the Georgetown University Medical Center
The patients were given increasing doses of Nilotinib (150mg to 300mg/day) that were are significantly lower than the doses of Nilotinib used for CML treatment (800-1200mg/day).
The researchers took cerebrospinal fluid (CSF; the liquid surrounding the brain) and blood samples at the start of the study, 2 and 6 months into the study.
Nilotinib was detected in the CSF, indicating that it had no problem crossing the protective blood-brain-barrier – the membrane covering the brain that blocks many drugs from entering.
Participants exhibited positive changes in various cerebrospinal fluid biomarkers with statistically significant changes in an important protein called, Tau, which have been shown to increase with the onset of dementia.
The researchers found a significant reduction (>60%) in levels of α-Synuclein detected in the blood, but no change in CSF levels of α-Synuclein.
The investigators report that one individual confined to a wheelchair was able to walk again; three others who could not talk were able to hold conversations.

If the outcomes of this study are reproducible, then we here at the Science of Parkinson’s are assuming that Nilotinib is working by turning on the garbage disposal system of the remaining cells in the brain and allowing them to function better. This would suggest that there is a certain level of dysfunction in those remaining cells, which would be expected as this is a progressive disease. The study researchers reported that the small, daily dose of nilotinib turns on autophagy for about four to eight hours, and if that is enough to have such remarkable effects, then this treatment deserves more research.

The results of the study are intriguing and the participants of the study will continue to be treated and followed to see if the improvements continue.

BUT before we go getting too excited:

While these results sound extremely positive, there are several issues with this study that need to be considered before we celebrate the end of Parkinson’s disease.

Firstly, this study was an open-label trial – that means that everyone involved in the study (both researchers and subjects) knew what drug they were taking. There was also no control group or control treatment for comparative analysis in the study. Given these conditions there is always the possibility that what some of the subjects were experiencing was simply a placebo effect. Indeed the lead scientist on the project, Dr Fernando Pagan, pointed out that “It is critical to conduct larger and more comprehensive studies before determining the drug’s true impact.”

In addition, according to Novartis (the producer of the drug), the current cost of Nilotinib is about $10,360 (£6,900) per month for the daily 800mg dose used for cancer treatment. Even if the dose used in this study was only 150 to 300 mg/daily, it would still make this treatment extremely expensive.

Thirdly, Nilotinib has a number of adverse side-effects when used as an anti-cancer drug (at 800mg/day). These include headache, fatigue, nausea, vomiting, diarrhea, constipation, muscle/joint pain, skin issues, flu-like symptoms, and reduced blood cell count. It may not be the nicest of treatments to tolerate.

There are important reasons for optimism, however, with the results of this study:

In 2010, a group of researchers published a paper demonstrating the neuroprotective effects of another cancer drug very similar to Nilotinib. That drug was ‘Gleevec’

Title: Phosphorylation by the c-Abl protein tyrosine kinase inhibits parkin’s ubiquitination and protective function.
Authors: Ko HS, Lee Y, Shin JH, Karuppagounder SS, Gadad BS, Koleske AJ, Pletnikova O, Troncoso JC,Dawson VL, Dawson TM.
Journal: Proc Natl Acad Sci U S A. 2010 Sep 21;107(38):16691-6.
PMID: 20823226

And that Gleevec publication was followed up a couple of years ago with a second study demonstrating the neuroprotective effects of another Abl-inhibitor: Nilotinib!

Title: The c-Abl inhibitor, nilotinib, protects dopaminergic neurons in a preclinical animal model of Parkinson’s disease.
Authors: Karuppagounder SS, Brahmachari S, Lee Y, Dawson VL, Dawson TM, Ko HS
Journal: Sci Rep. 2014 May 2;4:4874.
PMID: 24786396

These studies provided a strong rationale for testing brain permeable c-Abl inhibitors as potential therapeutic agents for the treatment of PD. The phase 2 trial at Georgetown will be starting in early 2016 and we will be watching this trial very closely.