I was curious about the the current work focus of the PAA Chief...

I was curious about the the current work focus of the PAA Chief Scientific Officer, Dr Nicky Wallis, and asked what can she tell us about the science work in progress.

Here’s the full response:

Hi Rick,

Great question and I would love to go into some detail for you!

Bringing together what has been observed following monepantel treatment, including but not limited to: changes in autophagy related markers, anti-tumour activity, and early signs of efficacy in patients with ALS, we needed to consider what diseases might show the most promise. More specifically, which diseases share common underlying pathophysiology with MND? Based on protein aggregation and the potential role of autophagy, neurodegenerative diseases made the most sense.

Next was to think about which model or models to use and what kind of experiments might give us robust data, in a timely manner. None of the models described below can necessarily give us all the answers, and there are of course pros and cons associated with all these which I have briefly touched on.

Cell lines: are very fast and give highly reproducible results. They are quickly at hand because they can just be thawed from the freezer, so you don’t need animal ethics or factor in animal breeding/ordering time. These cells have been hybridized with cancer cells or genetically modified to be immortalized. You can create cell lines carrying mutations associated with the disease of interest, e.g., SOD 1 mutations. The downside is that they are one-dimensional, and the results may not translate well as you move ‘up the chain’ to animal models, and then onto humans.

Primary cell culture: these can give you more translatable data than cell lines, and you can grow combinations of cells together to more accurately mimic a real system i.e., astrocytes with neurons or motor neurons. You can use cells from disease model mice or 'wild type' mice, or you can model the disease in the cell culture model by inflicting specific injuries or stressors e.g., oxidative stress, excitotoxicity (over stimulation of glutamate receptors). The downside being that these are time-consuming, prone to infections, need animal ethics and have longer timelins due to need potentially order animals.

Organoids: these are essentially cells which have been grown on matrices to form complex, more realistic networks of cells which are much better models, arguably better than mouse models. You can ‘play’ with an array of cells in these systems and really get stuck into the cross talk between cells and tease apart signalling pathways and understand if/how your drug might be working. The downside being the expertise and equipment needed.

iPSC: induced pluripotent stem cells. These are another fairly new kid on the block. These cells have been reprogrammed into specific cell types (like motor neurons, neurons, astrocytes, microglia), after taking a skin biopsy or sampling whole blood, and these are typically taken from patients with the disease of interest i.e. from a person living with Alzheimer’s disease, with an APOE ε4 mutation. The initial reprogramming to turn that biopsy into the cell type of interest is highly specialized and can take months to optimize and ensure you have the cell type you think you have! So, the downside is the potential lead time to use them, and the cost, but the benefits and potential are vast, and these are well regarded models of disease.

Animal models (mouse): although there has been a regulatory shift away from using animal models in clinical development, they remain a very useful tool. There is an ever-increasing range of models available, and they have been shown to accurately reflect many aspects of human disease. However, the cost and timelines for using animals models can be significant, and such studies need to allow sufficient time for animal ethics, breeding, importing, establishing the colony. But the amount of data you can collect through these studies is vast: from behavioural and cognitive testing, motor function, social behaviour, vital signs, heart, blood and urine analysis, gene expression, histology (tissue staining to examine cellular and tissue morphology), and electrophysiology ( recording electrical activity in the brain and muscles to assess neural function).

Then comes the next bit- designing the actual experiments! By reading up on published data in key diseases of interest across a range of studies from cell lines, primary cell culture, through to mouse models and human clinical data- this has helped to shape the best path forward. By building on this already established knowledge, each experiment is set up to employ appropriate reference compounds, positive and negative controls, inhibitors and inducers, which are used in an orchestrated manner to help us map the ‘on’ and ‘off’ signals down a pathway, subsequently enabling us to monitor if, how and where monepantel might be working. Other typical endpoints that are used in these types of experiments in addition to the above might include: cell viability, assaying levels of key transporters associated with neurodegenerative diseases e.g., EAATs, which transport glutamate, the major excitatory neurotransmitter, measuring mitochondrial function, length of neurites, electrical activity of neurons, measuring markers associated with inflammation (like cytokines), measuring reactive oxygen species, and assessing the morphology of cells under the microscope.

I hope that helps gives you a healthy behind the scenes snapshot of the science!

Cheers,

Nicky

It’s on the Investor Hub @ https://investorhub.pharmaust.com/announcements/6431439#question-section

To have such a friendly, open, communicative, informed and detailed response from the Chief Scientific Officer is greatly appreciated, and highly indicative of the competence, responsiveness and calibre of our PAA management colleagues working in the trenches, and at 7:31pm on a Friday night!

I’m impressed and delighted,

Thank you Nicky!

Cheers,

Ice