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Firstly, (and this is an assumption I am making) Amplivant probably helps extend the time Moditope petides are in the blood stream/site of vaccination. Secondly, Amplivant (and it’s payload) binds TLR1/2 receptors on the surface of the cell. In doing so, it triggers the TLR signalling cascade which results in pro-inflammatory cytokine release and dendritic cell activation. In turn, this results in inflammation and in doing so an up-regulation of MHC-class II molecules on the surface of the dendritic cell. At the same time, other moditope peptides in close proximity to the surface of the dendritic cell and so are engulphed by the cell membrane through a process called phagocytosis (literally Greek for to eat and cell). The moditope peptide is then broken down and loaded onto the MHC Class II molecule. This then is trafficked to the surface to present the peptide to a helper T-cell. Third and forth) In turn, the helper T-cell release other cytokines which recruit other cells to help combat this target.

So Amplivant does the following
- physically takes Moditope peptides to the APC
- activates signalling pathways which upregulate MHC Class II proteins
- Increased MHC Class II proteins means more opportunity to APC to present moditope peptides to CD4+ helper T-cells.
- Increased inflammation meaning recruitment of further immune cells, which potentiates these steps. In turn helping reduce the amount of peptide needed to obtain a result.

The reduction in the amount of peptide needed translates two fold – firstly into how much of a dose you have to give somebody to see an effect (good for the patient), reduced costs to manufacture (increasing profit margins and potential market size).

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RP,

I didn't mean to ignore your question. The last few days have been a bit of a rollercoaster for me, so haven't really had a chance to put something down on paper. So in response to your statement 'I hadn't realised that amplivant helps the vaccine find its way to the DC.'

The immune system – specifically the innate immune system is able to recognises specific structures present on bacteria or viruses known as pathogen-associated molecular patterns. These for example can be viral or bacterial components such as proteins, carbohydrates, fats (lipids) or nucleic acids (DNA/RNA). These PAMPs are recognised by a range of different receptors, one of which includes the Toll-like receptor family. The TLR family of proteins are found on the surface or inside many immune cells such as antigen presenting cells or dendritic cells to name a few.

When a TLR ligand binds to it’s target binding partner, a signalling cascade is initiated within the cell (https://bit.ly/2FZZkt9) which results in the activation of this cell. It also results in the secretion of pro-inflammatory molecules such as cytokines and upregulation of other co-stimulatory molecules.

Binding of a TLR ligand, results in activation of the adaptive immune response as dendritic cells migrate from the site of infection to the nearest lymph node where they present bacterial/virally derived antigens to naïve CD4+ cells. At the same time dendritic cells express co-stimulatory molecules which result in the differentiation of CD4+ cells into TH1 cells or TH2 cells.

So where does Amplivant come in?

Amplivant is an adjuvant, which is a chemical or immunological substance that is added to a vaccine to improve the immune response. An adjuvant is designed to stimulate the immune response but also to help modify the immune response to bias it towards possibly an antibody response or alternatively to a T-cell response. Common adjuvants include things such as aluminium hydroxide or paraffin oil. Adjuvants work by a range of mechanisms including a) extended the time that an antigen is present in the blood (and therefore being presented to the immune cells), b) helping the antigen presenting cells absorb the antigen, c) activating other immune cells such as macrophages and lymphocytes or d) helps support the production of cytokines. I would say most likely in this case it is all of these.

From what we know Amplivant is a modified Pam3CSK4 (https://bit.ly/3j1rN0k) - which in itself is a synthetic triacylated lipopeptide that acts as a TLR1/2 ligand (for clarity, lipopeptides are a peptide with a fatty molecule on the end) which can itself be joined onto synthetic long peptides (i.e. moditope peptides).
1/2

RP,

I didn't mean to ignore your question. The last few days have been a bit of a rollercoaster for me, so haven't really had a chance to put something down on paper. So in response to your statement 'I hadn't realised that amplivant helps the vaccine find its way to the DC.'

The immune system – specifically the innate immune system is able to recognises specific structures present on bacteria or viruses known as pathogen-associated molecular patterns. These for example can be viral or bacterial components such as proteins, carbohydrates, fats (lipids) or nucleic acids (DNA/RNA). These PAMPs are recognised by a range of different receptors, one of which includes the Toll-like receptor family. The TLR family of proteins are found on the surface or inside many immune cells such as antigen presenting cells or dendritic cells to name a few.

When a TLR ligand binds to it’s target binding partner, a signalling cascade is initiated within the cell (https://bit.ly/2FZZkt9) which results in the activation of this cell. It also results in the secretion of pro-inflammatory molecules such as cytokines and upregulation of other co-stimulatory molecules.

Binding of a TLR ligand, results in activation of the adaptive immune response as dendritic cells migrate from the site of infection to the nearest lymph node where they present bacterial/virally derived antigens to naïve CD4+ cells. At the same time dendritic cells express co-stimulatory molecules which result in the differentiation of CD4+ cells into TH1 cells or TH2 cells.

So where does Amplivant come in?

Amplivant is an adjuvant, which is a chemical or immunological substance that is added to a vaccine to improve the immune response. An adjuvant is designed to stimulate the immune response but also to help modify the immune response to bias it towards possibly an antibody response or alternatively to a T-cell response. Common adjuvants include things such as aluminium hydroxide or paraffin oil. Adjuvants work by a range of mechanisms including a) extended the time that an antigen is present in the blood (and therefore being presented to the immune cells), b) helping the antigen presenting cells absorb the antigen, c) activating other immune cells such as macrophages and lymphocytes or d) helps support the production of cytokines. I would say most likely in this case it is all of these.

From what we know Amplivant is a modified Pam3CSK4 (https://bit.ly/3j1rN0k) - which in itself is a synthetic triacylated lipopeptide that acts as a TLR1/2 ligand (for clarity, lipopeptides are a peptide with a fatty molecule on the end) which can itself be joined onto synthetic long peptides (i.e. moditope peptides).

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Apologies, but I’ve been battling a range of things both personal and at work over the last few days, so following this board has been last on the list I’m afraid. Not ignoring people, just priorities are elsewhere.

Half day tomorrow, so promise I will answer in full tomorrow when I get time.

https://register.gotowebinar.com/register/6048268738324767503?dm_t=0,0,0,0,0

For anyone interested, there’s a free webinar on the biopharma drug development pathway: origins and comparison with small molecule discovery.

September 24th at 1500 BST (UTC+1).

https://www.nytimes.com/2020/09/19/health/astrazeneca-vaccine-safety-blueprints.html

‘ If a serious side effect was definitively linked to AstraZeneca’s vaccine, scientists would need to determine if its root cause stemmed from the adenovirus vector, or perhaps the coronavirus genes it carried — connections that could raise concerns about other companies’ products that rely on the same components.’

Will be interesting to see how this pans out. Especially if it causes a complete halt to AZs vaccine due to safety risks which are vector related rather than Covid-19 component related.

I see we're not alone! I guess it's just they're all kind of house hold names. We're not (yet!)

Wonder whether there’s a rhyme or reason?! Maybe something to ask at AGM if allowed

Many pharma/biotech companies have seen a boost, especially when they announce they’re doing Covid work.

I would be interested to see in a parallel universe, what the share price would be doing if we were called Scancell Bio/Pharma, rather than Holdings. Wouldn’t surprise me if we would see a positive reflection in the share price.

Just thinking aloud here.

Episode 3 will be later today/tomorrow. Weather today looks good and I have an allotment to weed and a spud harvest to finish!

Will respond later. Have a good day all.

Also AB and anyone else who reads this, if there is anything you don’t understand or is ambiguous, please just say and I will try my hardest to clarify for you and everyone else. Always open to questions.

AB

Funny you should say that, I’m currently designing the projects our Master’s students will be doing this year. Taught last years students and am widely involved in STEM outreach to GCSE and A-level students.

So whilst it forms a fraction of a percent of my usual day to day work, it does factor in there.

It could mean that Moditope has applications far more reaching than just the cancer field and could stretch into other fields such as Alzehimers and Parkinsons (market size for these combined is $13.3bn for AD by 2023 and $5.69bn for PD by 2022 (AD https://bit.ly/3hH0KGh and PD https://bit.ly/32LgKCA)).

The other downside to Moditope is the fact it is a peptide drug. Cost of manufacture of peptide based drugs increases as the length and complexity does, yields also drop off in the synthesis of peptides as they increase in length. In comparison to a DNA based drug, costs will be higher in manufacturing. An example being mAb production costs can be $36/g (https://bit.ly/35Rb4cm), DNA based drug are cheaper still, small-molecules the cheapest (think pennies per kg). Compare this to a peptide based drug which can cost over $100/g (https://bit.ly/33ERrS4).

This was the basis behind the DNA moditope thread yesterday – for me, if you can get cost of manufacture down then your profit margins go up and your market size increases. Lindy stated in her email to Inan that whilst moditope peptides can be encoded and delivered by DNA vaccine, the cellular mechanisms which generate the required siPTMs generate a less effective response than delivering the peptide itself. Further details can be found here (https://bit.ly/2RHaHsE), though as with any science we are moving forward and costs are coming down which means peptide drugs could be attractive. Another benefit to Moditope is you would only need to be dosed a few times, it’s not like a chemotherapy drug where you have to be dosed multiple times with larger doses.

4/4/end (note this went on an additional post, so the first two were labelled with 1/3 and 2/3 respectively. These should be 1/4 and 2/4).

Moditope (Modi-1) consists of short linear peptides taken from two proteins which are commonly modified in cancer cells. Vimentin a key structural protein involved in many cancers and alpha-enolase a protein involved in glycolysis (the glucose metabolism pathway). Both of which are prone to siPTMs in cancer cells. These short peptide sequences are chemically synthesised in the lab and already have the siPTMs attached (relatively easy to do in the test tube). Then these are fused to another protein called a toll-like receptor 1/2 agonist (amplivant). Basically, to cut a long story short this acts like a post-code, directing the moditope peptides to an antigen presenting cell. Here they are taken up by the APC and presented on MHC class II proteins to T-cells. The T-cell then infiltrates the tumour. Through secretion of interferon-gamma, it is able to induce inflammation. Inflammation results in an upregulation of MHC class II, which in turn results in the T cell being activated and killing the tumour directly.

So in this round about way, why is this platform important? Firstly, and similarly to Immunobody, it does all of this inside the body. Utilising normal pathways (e.g. no need for CAR-Ts and you’d hope less side effects of treatment). Secondly, and to me more importantly, it focuses the immune system on the inherent dysregulation we see inside of cancer cells (less off-target effects). Rather than a specific target protein expressed on the surface of a cancer cell, it is more broad than that. In doing so, the cancer cell has far less opportunity to mutate and escape (less chance of the cancer mutating and escaping treatment)…you’re not targeting a specific individual target, you’re targeting the underlying biological processes which cancer cells need to survive (broad application to a vast range of cancers). You also have the ability to look at other siPTM’d protein targets (extra strings to the bow).

Now, for me the risks for moditope are as follows – whilst cells generally function correctly, we do see oxidative stress in other non-cancerous situations. Other diseases such as Alzheimer’s and Parkinson’s have been linked to oxidative stress. So for me, a risk could be we see neurological effects that aren’t seen in mouse models as we enter the clinic. Oxidative stress is also linked to some cardiovascular diseases and diabetes. So it would be interesting to see whether these are affected….it will all come down to whether the peptides chosen for Moditope are specific to cancer. Now, to counter that worry we note that SCLP have chosen antigens which are commonly modified in cancer cells (further details here https://www.scancell.co.uk/modi-1). So it seems they also may have thought similar lines with regards to risk. The other argument you could make, is that this could be seen as a benefit rather than a risk.

3/ (now 4)

So what causes cellular stress? In the context of cancer, cells are growing at an incredibly fast rate – far higher than we would see in a normal cellular context. To be able to divide, the cell has to copy all its DNA without making mistakes, make new proteins for all the biochemical pathways it needs in both daughter cells (by transcribing the DNA and then translating it into protein). To do this takes vast amounts of energy, which in turn needs nutrients to fuel it and oxygen. So what we see is a lack of oxygen and a lack of nutrients in the cancer cell, cellular functions start going into disarray and the result we get cellular stress. The way cancer cells try to combat this is to upregulate glucose uptake and ferment the resulting lactic acid to lactate to generate energy (the warburg effect) https://bit.ly/2RGFeqE. (Tangentially, for those who are interested, this is how a PET scan works, the drug they inject into you is fluorodeoxyglucose such as 18F-FDG, which is taken up in far higher amounts by cancer cells than by the rest of the body, thus labelling the cancer in the resulting image.) Furthermore, to try and source further energy the cancer cells start digesting their own internal proteins in a process known as autophagy (auto – self, phagy – to eat). Combined both of these processes cause stress-induced post-translational modifications of proteins to occur. In particular (and the ones we are interested in) citrullination and homocitrullination (details are in the diagram here https://www.scancell.co.uk/moditope).

So based on this, these siPTMs generally should be restricted to proteins within stressed cancer cells and not normally functioning cells (unique target). But how do you generate an immune response against these siPTMs? To generate an immune response from these, we have to present them to the immune system as linear peptides bound to a molecule called major histocompatibility class II (MHC-II) molecules for recognition by T-cells. However, here lies the problem. MHC class II proteins are generally not present on the surface of cancer cells, except where inflammation is occurring. Here is where Lindy et al. have got around this. Enter Moditope.

2/3

For me, the real asset I see with SCLP is the fact that it's a platform based company, with three (four if you count the Covid-19 platform) separate strings to its bow. Broadly coming at the same problem, but from multiple angles. The problem driving this research is cancer cells fundamentally are our own cells, but that have gone rogue. Rather than being treated as foreign by the body (as a bacteria or virus would), the body ignores them. So the question that is being answered here is how do we retrain the immune system to attack these rogue ‘self’ cells but in a way that has little/none off target effects, is highly effective in the way that it does it and fundamentally is workable as a therapeutic?

Moditope – a protein (and technically a DNA) based platform to target the dysregulation seen within cancer cells.

Moditope (and associated patents) covers a protein based vaccine which consists of a number of peptides (short pieces of protein) which have stress-induced post-translational modifications on. If we go back to basics here. DNA encodes proteins –> transcribed into mRNA (an intermediate genetic molecule) -> mRNA is then translated (read) by the cellular machinery which then builds a long chain of amino acids (the individual building blocks that make up a full protein chain). These chains then fold into the 3D structure which is a fully mature protein. After a protein is translated (and sometimes after it has folded), the body is able to add extra embellishments to a protein (known as post-translational modifications). These are varied, from adding fat molecules (lipidation), phosphate molecules (phosphorylation), adding sugars (glycosylation)…the list goes on. These PTMs have many functions, they can regulate the function of a protein (switching it on or off), they can tag a protein and mark it for destruction. Generally PTMs are added by additional enzymes in the cell. However, a select few PTMs are ‘enzyme-free’ and some of these enzyme free PTMs are caused by environmental factors such as cellular stress – hence we see the introduction of the term stress-induced PTM or siPTM for short.

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Will try and get the second instalment done tomorrow - it’s been a long week and the whisky cabinet and bed are calling!

As an example, whilst not to medical grade quality, routinely during my PhD I was making 1g of DNA, overnight, in a few flasks of bacteria, literally grown on lab grade milk powder and marmite….in relative terms that’s 250 doses of the 4 mg patients, or 125 doses of the 8 mg patients for SCIB1 trial… (high profit margins). It’s plug and play (can generate more drugs and quickly), targets viruses as well as cancers (even bigger target market).

Downsides – as with any immunotherapy, especially as they are in their infancy, we don’t know long term effects of modifying T-cells. IB holds a massive advantage here over CAR-T cells though and it’s why I put my faith in this platform. It works it in a semi-natural way by utilising the immune system inside you. The pathways you are using are the same ones used normally by your immune system when they encounter something foreign. You are not removing cells, re-engineering them and putting them back inside you as you are with CAR-T. All you are doing is using natural mechanisms to make them realise that ‘this target is actually foreign – kill it.’ This has the added benefit of having limited reason for adverse effects that you may see with other drugs especially CAR-T cells which suffer from some pretty severe side effects including cytokine release syndrome, neurotoxicity and potentially death.

Talking about adverse effects the worry with any immunotherapy is that if for some reason there are off-target effects, you can’t easily switch them off. Unlike if a pill is giving you bad side effects you can stop taking it and they generally will resolve. In the case of an immunotherapy, this isn’t the case. So the choice of target is key and IMHO this is where the biggest risk to IB is. The choice of epitope to add into this construct. We put our faith in Lindy et al., to make this decision and test in the lab, in pre-clinical models etc. But we will never know just how good those models are until we start dosing them in the patient. So far, the choices have been spot on and we have seen incredible results. But that doesn’t mean the wrong choices can’t be made. So, like any drug testing, there are risks involved. We put our faith in the scientists that design, make and test these. In the case of immunotherapies, we generally have to balance that risk with the reward.

Overall, in the cancer world if SCIB1 makes it through trials to the clinic, CAR-T will be seen in the annals of history as the stepping stone between chemotherapy and IB. Covidity (covid-19 immunobody), will be seen as the end to long-term viral infections (sadly I fear excluding HIV) as we know it.

3/3/end

So a summary so far – DNA vaccine (cheap to make), plug and play set-up (easy to target other things or allows you to test many different variants of constructs in parallel for very little extra cost), patent (covers any protein – i.e. both cancer and virally infected), generates a robust T-cell response from both T-helper and T-killer cells.

Currently the market by far is looking at CAR-T cells. Billions are being ploughed into this form of therapeutic both in early stage, pre-clinical, clinical and therapeutics. Initially it’s only been licenced for haematological malignancies, but soon I’m sure they’ll be targeting solids too. But why do I mention this?

CAR-T briefly, tries to do what IB does….but in a test tube (https://bit.ly/2HdQvg2). Whilst CAR-T therapies do work for most patients, they have many drawbacks. A vast cost to make, with huge potential failure rates (lack of T-cells, lack of expansion of them in the test tube, lack of ability to transform enough of them to expression your CAR, lack of T-cells in the patient to begin with, problems with rejection of the CAR-T, horrible side effects, lack of engraftment…the list goes on). A single dose of Kymriah for B-ALL treatment costs £282k (https://bit.ly/3hHDlnZ) but has a manufacturing failure rate upto 9% (https://bit.ly/3hFahxj), Yescarta from Gilead does slightly better at 1% manufacturing failure rate. But still, 1/100 doses fail to meet manufacturing standards (the patient still may get this substandard product free, but for the company all that time and energy is wasted – hence the high list price). The industry is ploughing vast amounts of cash into a system which when it works, works well, but poses a lot of points of failure. Failure which could mean a patient doesn’t get the treatment they need and so dies through no fault of their own.

Look at this now in the light of IB. With IB don’t need to generate a drug for each individual patient – you have an off the shelf drug rather than a bespoke drug (bigger target market as more people can afford the drug). DNA is stable, meaning you can have this as an off-the-shelf product potentially – if you know the target is expressed on your tumour, you could have the dose that day (CAR-T take a month to make….time that many patients cannot afford to lose). You can dose it multiple times - I would guess as many as you need, so long as the target is still present on the tumour (meaning you’re not too limited by how much you can give or how much you can make). DNA is easy to make and you can create vats of the stuff rapidly and cheaply.

2/3

For me, the real asset I see with SCLP is the fact that it's a platform based company, with three (four if you count the Covid-19 platform) separate strings to its bow. Broadly coming at the same problem, but from multiple angles. The problem driving this research is cancer cells fundamentally are our own cells, but that have gone rogue. Rather than being treated as foreign by the body (as a bacteria or virus would), the body ignores them. So the question that is being answered here is how do we retrain the immune system to attack these rogue ‘self’ cells but in a way that has little/none off target effects, is highly effective in the way that it does it and fundamentally is workable as a therapeutic?

ImmunoBody – a DNA based platform to target a protein that is unique or highly upregulated in cancer.

It’s getting late so tonight’s musings will be on this.

ImmunoBody (and associated patents) covers a DNA based vaccine which encodes any T-cell epitope but not regulatory T-cell epitopes. In essence, the patent covers any protein which can elicit an immune response. Furthermore, DNA is incredibly easily to manipulate. You find a new T-cell epitope you want to target, within an hour you have designed and ordered the construct, within a week you’ll have it to start testing. It is if you can use the term ‘plug and play’. We’ve seen this in the fact SCIB1 (TRP-2 and gp100 targets) and SCIB2 (NY-ESO-1). It’s quick, easy and cheap to generate new vaccines. DNA synthesis to make a new immunobody construct these days is cheap (probably £120-200 all in depending on complexity of DNA sequence that have to be synthesised), so as a platform this is incredibly versatile and easy to change. Couple this to the fact the patent covers any T-cell epitope….so covers both cancer and viral cells.

Dig a bit deeper, we see the design of the vaccine is incredibly well thought out and designed such that it elicits a robust T-cell response from two T-cell components key to being able to target cancer/virally infected cells . The DNA vaccine is taken up into antigen presenting cells in one of two ways. Directly – the APC takes the vaccine up, transcribes and translates the DNA into mRNA and then into protein, whereby it is processed and presented to T-cells on MHC I/II or indirectly, is taken up by muscle cells, transcribed and translated into the protein version of immunobody (which in essence looks like an antibody). Here it binds the FC receptor on the surface of an APC, is internalised, processed….as above. Through these two slightly different pathways IB is able to generate not only a cytotoxic T-cell response but also a T-helper response too. (https://www.scancell.co.uk/immunobody).
The results from SCIB1 have been pretty striking to say the least. Patients who to put it bluntly should be dead due to advanced melanoma are still with us today because of this incredible piece of ingenuity.

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