Reprogramming Aggressive Prostate Cancer to Enable Immune mediated Tumor Elimination - Paul Mathew

Yeah. >> Hi, this is the cancer patient lab and I'd uh like to introduce uh Paul, Dr. Paul Matthew who's joining us. He's with TUS University. Um one of our members, David Plunkett, uh saw him uh present

some very interesting material in a separate session and thought that he would be a good candidate to speak to our community. Um so as you will see with the slide here um he's focusing on prostate cancer and some novel approaches to make it uh susceptible to

uh immune treatment. Um and so that's I think a futuristic topic that will be of interest to many people because it opens up a whole new avenue of method of action for treatment for people with prostate cancer. With that turning it over to you Dr. Matthew.

>> Thank you. Um thank you for the this great opportunity to talk to people who are facing this disease and think about it probably every day of their lives um and worry about it uh the future and um my personal relationship with this goes

back 25 years when I joined as a junior faculty at MD Anderson in Houston in 2001 my mentor assigned me prostate cancer you know amongst the generary cancers I became very interested in problem over

the years in why the cancer behaved in this very stereotypical fashion for the most part um with the spread to bone and you know obviously metastasis which is cancer spreading from one side to the other this is how life is threatened right it's rarely because it's growing

in one spot although there ex exceptions to that for example brain tumors don't metastasize that's how they become dangerous they grow in in enclosed space um whereas cancers like prostate express themselves differently by spreading to distant organs but they do

so in non-random manner. So metastasis is a non-random event, right? It's not like the cancer is growing any way it pleases. It can only grow where it's it has fertile opportunity. And there's something unique about the bone marrow

micro environment that is particularly hospitable to prostate because in at least 70% of men um bone will be the only site of metastasis and 90% uh the bone is involved and of course there are other sites like lymph

nodes perhaps liver and lung to lesser extent certainly almost never the brain so it's a highly stereotyped pattern and I became you could say obsessed with that in the years old is I was at MD Anderson and one of the thoughts I had you know

with so many patients you know hundreds of patients treating them relatively similar way with hormone therapy and chemotherapy maybe radioisotopes in those days more recently PARP inhibitors a class of drugs for tumors that are muted mut mutant for the bracka genes

and so forth were relatively limited repertoire of therapy but none of which in my estimation had to do with this behavior that I became obsessed with. So this became almost like a Rosetta stone. Like if you could decode this mechanism of why this

gland that sits below the bladder relatively small in nature when it develops cancers at high frequency obviously the most frequent cancer in uh among men is prostate cancer right it's the most common malignancy but when it

does spread it spreads to the bone in this way. This is a bone scan showing very high volume bone metastasis occupying the majority of the of the uh skeleton and you in this patient um you may not actually see anything in the

lung liver bone if you did a CT scan. So I became this became the obsession and the report I can give you after you know you could say 16 years of effort at Tus Medical Center working on this problem singularly uh is that we have we think

we have the a a major explanation not the only explanation but a major explanation that this is likely mediated by integrants and I'll tell you about what integrants are and I'll tell you why two of them the alpha v and the alpha of these integrants collaborate uh

and why these this particular antibbody that we developed might be the answer to the problem that you're seeing here and and uh and with that I shall move forward. I the TUS does have a patent on this antibbody that we developed for this problem and I hope to tell you

something new about prostate cancer that you might not have heard before. you probably heard a lot of lectures from scientists or physicians who have come to your forum and I'm I'm hoping maybe I'll bring a new perspective um and that this new perspective is actually essential for understanding

everything uh about u prostate cancer that is dangerous all right so first I'll introduce you to the normal prostate gland imagine for simplified purposes that it's like a balloon or a sphere that has an outer layer called a

basil layer and it has an inner layer called the luminal layer. So the basil layer is the one that interacts with the environment. It anchors it to the environment. It mediates the transactions with the environment that keeps things in order. It's that thing

that specifies order in the gland, you know. Um so this interaction with the environment is crucial and it is also the source the uh you could say the stem cells of the prostate gland and many glands are organized like this. The breast is also in this way and there are

many others bladder and so forth. And so this blood these basil layers harbor these stem cells that they can replicate themselves but they can also have a secondary pathway to differentiate into these luminal cells

that have a specialized function. And in the prostate that specialized function is secretion of enzymes and one of which uh is the PSA um known as a marker for for screening and and monitoring prostate cancer but

also many other things that go into the um the u the principal function of the prostate is to liquefy the semen and contribute to the ejaculatory volume. So that's a highly specialized function and that's regulated by principally by testosterone or the androgens. So the

basil layer is not regulated by androgens. In fact, it lacks the androgen receptor. Whereas the luminal layer expresses the androgen receptor. All right. Um so this is like some rudimentary points I wanted to make about the gland. It has two layers. The

basil interacting with the environment that is and receptor PSA negative and then a luminal layer that is specialized as secondary functions. It is andigen receptor and PSA positive. This is just a cartoon version. And here's a real version over here on the left. These

nice harmonious uh well- behaved glands that are that are benign. And this brown stain is the one that decorates the basil layer. It's a little thin layer. It's a little bit hard to see. And the larger ones that are plump and well organized here, these are the luminal

layers. And that's the this is the lumen. Well, luminal meaning uh pointing towards the cavity, the lumen of the gland. And this is where the secrettory volume is is assembled and passed on into the ejaculatory ducts. So that's

your fundamental organization of the prostate gland. Why is that important? It is very important uh as I will show you next. So firstly the the basil layer and and the lumininal layer we can have markers

for them. the CD49F marker if it's high uh you know that's a basil layer if it's low it's a luminina layer you can actually mark them and study them um to see how they be uh the their gene signatures obviously gene signatures

means from DNA to RNA meaning the message from the the genome is passed on to uh RNA and then the RNA makes the proteins and the proteins dictate the behavior. So we can look at the array of signatures of the expression signatures

of RNA and understand what type of behaviors are going on in there. That's called you know transcriptional analysis or gene expression signatures. So here's the array of gene expression signatures for the basil layer and here's what they are for the luminina layer and I've told

you about what they are already. I want to point out two important differences. One is that the basil layer has this so-called mix signaling and cell adion. Remember what I said about the basil layer adearing to the outside the matrix. Yeah. So it requires this

adesion sort of program to help it work amongst others. But I'm just calling these to your attention because they're relevant to our discussion that follows. And when you talk about the luminal layer, the ones that you'll recognize is androgen receptor signaling. Well, of course, uh that is key and but also you

might not know the immune response is actually active in the lumininal layer, not so in the basil. So that's the normal gland. Okay. But what happens if you take cancers that originate from the prostate and use the same paradigm to

separate basil and luminal signatures? And what you find uh in this this is the process of scientists separating them and looking at their signatures and so forth is that basil uh is that benign

normal glands and cancerous glands when separated by this basil and luminal you know markers they look very much identical. I'm going to reproduce this slide in a horizontal fashion here so you can look here and see benign cancer benign benign cancer. Look at look at

the the way they're being separated by the basil marker and look at the gene signatures essentially overlaid red and green. They look almost identical, don't they? So if you're a normal gland or a cancer, if you're if you're marked by the basil layer, your gene signature is

pretty much the same. So what what this and if you're luminal the same thing u you know you're carrying the same gene set of gene signatures and you can see how very different basil and luminal are the red and green simply don't overlap

so they're terribly different. So that's a little secret. Um I don't know how many people actually know this. Uh surprisingly few. Um and what this is essentially saying put another way is cancers have a very

powerful memory of the gland from which they arose. Okay, it's not that cancers are either basil or luminal. They contain ad mixtures of the two uh and you know in varying proportions and as it turns out the tumors that are more

basil than luminal are the more aggressive ones. All right. uh and we'll and here's the data to show that as you go from a low glyon grade to a high gleon grade there's a progressive enrichment in the

basil score that's within the gland of prostate gland in in terms of primary cancers of the gland and when you go from organ confined disease to metastatic disease whether it's hormone refractory disease or hormone sensitive

disease you see the same enrichment in the basil signature the CD49 high defined signature. All right, remember I said make an adesion and invasive programs. All right, so this is a large study that

was done by UCSF uh and other investigators taking over 600 men with metastatic castration resistant prostate cancer. What is castration resistant? You're on hormonal therapy uh to control an advanced

cancer. the PSA is rising uh the scans are showing progressive disease even though the testosterone is kept low with treatment that's castration resistant and using this paradigm to separate basil and luminal you can see that about

55% of p that's a good proportion of patients met the definition of basilen enriched prostate cancer and 45% met the definition of luminalenriched prostate cancer mind you just to remind you this is patients who not been who have been

treated with hormone therapy already. So what happens is when you're treated with hormonal therapy, you can move from a luminal dominant androgen receptor regulated cancer to a more basil androgen receptor low uh phenotype and I'll talk more about that so-called

plasticity of disease. But here you can see there is a nice uh segregation of these signaling signatures for the basilen enriched to the left and for the luminal enriched to the right right lower and top left. And once again I

want to point out to the mick targets in the basilen enriched programs here. I mean there are others too those are relevant but we'll just focus on the mick for simplicity. And on the bottom right, we'll focus on the androgen response for the luminal as

well as this interfuron gamma and interfuron alpha which are immune signatures. So basil and luminal are very different uh in men with castration resistant prostate cancer. Um all right so this mick this this is where the

problem is you know with castration mick is a big problem. So what is mick? MC is an anka gene that is important in development but plays a big role a majority role in over 70% of human cancers and for the longest time it's been very difficult to target mick.

There's been a great deal of interest. It is a transcription factor. A transcription factor is something that goes from the cytoplasm of a cell to the nucleus and influences gene expression programs. These have been very difficult historically to target with therapy

although there's some progress now uh but rather limited but what I want to point out is that Mick is central to the basil phenotype the aggressive phenotype of prostate cancer and it has many different functions including promoting

gene instability and acquisition of mutations impairing DNA repair causing you know interfacing with the cell adesion program that I mentioned calling causing tumor cells to proliferate supporting these tumor cells with metabolic engines uh and evading

immunity. So all the all the bad things that cancers do, Mick has a hand in it, collaborating with other partners, no doubt, but this it regulates the multiple hallmarks of of aggressive cancer, including prostate. And because

we have a short lecture, I want to get right to the point and tell you that we think that integrine mechanis signaling, I'll explain what that is. Integrate mechanis signaling has a lot to do with how Mick works in aggressive prostate.

but likely other cancers as well. I'm going to tell you what integrants do. But firstly, here's um here's a here's a cartoon of an integrant. Alpha 5 beta 1. These are what we call hetrodimer. There are two of them together that form a

single unit. It's called alpha 5 beta 1 here. And here's another one with alpha V with its partner. And these two are basically um partners in crime if you will and they collaborate. There's a strong

interplay between these two alpha 5 and alpha v integrants in connecting uh cancer cells the basil type cancer cells to the matrix meaning the uh inanimate organic material composed of complex

proteins maybe labeled with carbohydrates and the like but it it connects the cell to that matrix and really forms a linkage to the inner cell skeleton. The cells, believe it or not, have their own skeleton. It's called actin cytokeleton. And that form allows

the cell to be, you know, flexible and and strong and pliant. But it also is a uh harbor for signaling processes. And the stiffer uh the actin cytokeleton, the more the signaling of a particular

protein called YAP YAP. It's called a yes associated protein. So yap will go to the nucleus once the the cell is under tension with the with the with the micro environment with these integrants mediating this tension and once it's in there what it does is it it does

something called bookmarking of Mick and enabling Mick to work. So, YAP enables Mick over 80% of Mick controlled sequences in the genome is enabled and and potentiated by this YAP. And YAP is

coming from that tension I was referring to. Now, what does that do? Well, if yap if they had the stiffness and um and Yap's in there and Mick is on, what happens is immunity is shut down and you get a cold

tumor. A cold tumor is a bad thing. It means it's not being recognized by the immune system. It's not been infiltrated by immune cells. They cannot destroy this uh lethal, you know, enemy, if you will. And it's essentially invisible. All right. But if you block these

integrants with the bicep specific antibbody that combats both integrants at once, you disable this whole tension architecture, yap no longer is active enough to get into the nucleus. And as a consequence, Mick is shut down. And when

Mick is shut down, voila, you get an interferon response that's very robust. It starts to secrete the tumor cell itself starts to secrete uh what we call chemocines that attract immune cells in there including natural killer cells and

macrofages to to to uh inflame the tumor. Now the cold invisible tumor is now inflamed and infiltrated with tumor cells which eliminate the tumor. All right. So that's published data which I I posted and I that's a citation that

I'll share with you. So just a little bit more on integrants. It's a little complicated but imagine here are your hetrodimer you know the two things the alpha and beta parts of the integrant connecting to the matrix. Here's a complex architecture to the cy

actin cytokeleton just to give us a little bit more mechanical impression of the complexity of this whole process. But essentially fibbronactin is is what we believed was had a lot to do with why prostate cancer cells got to the uh got to the bone

because the they were bind the integrants on the prostate cancer cell were binding to the fibonnectin in the bone marrow that's how it was colonizing the bone marrow and you know force matters and biology I guess that's another takeaway point I want I've been making this point but I'm

going to say it again force matters and biology might be something new for to to think about and I think you will hear more and more about this in the in the near future uh on a diverse array of of elite uh um issues. Most recently I read

a paper on early onset colurectal cancers. Those are going up very rapidly in folks below 40 and it could be that there is a problem in the rectum where uh maybe who knows dietary microplastics accumulating and causing stiffening and

so forth and that's changing everything with that interface between the basil layer and the matrix. So here what what I want to make a point about is suppose you take a a cell from the bone marrow and put it on stiff matrix as opposed to soft matrix you get completely different

fates. If it's on a stiff matrix it becomes a bone forming cell. If it's on a soft matrix it becomes a fat cell. So just I've simplified this relatively complex diagram to say something very simple. Stiff means one fate soft means

another fate. So just to simplify force matters in the cell fate and it certainly in matters in cancer biology and I think might be very central to the lethal phenotype of prostate cancer.

So here's some specific evidence that our bispecific antibbody when treating prostate cancer cells actually controls that signature that I referred to. Here it is again that basil signature. You see it here. Remember this diagram top left the basilen

enriched uh signatures the aggress the aggressive treatment resistant phenotype that that uh eludes immunity here that entire signature is under control. Red bars to the left means down reggulation. Green bars to the right means upregulation. So we're down reggulating

that basil signature with this antibbody through the mechanism that I proposed and upregulating the immune response. You can see that signature here. And what that results is in our tea models in mice, we are eliminating these very

aggressive androgen receptor negative prostate cancer cells uh in animal models very efficiently across a range of doses um in both what we call clonogenic assays and established tumors. Um so we have rather potent

evidence that it's not just in a test tube, it's in animal models as well. And that when we can show that the reason that these tumor cells are being eliminated is because of natural killer or ENK cells which are part of the innate immune system uh in this mouse

model. The reason we can show that is we deplete these natural killer cells the activity of the antibbody disappears. So here is the antibbody working very well to eliminate tumors in this mice. All these blue signatures are the tumor cells glowing under the imaging uh

expressing something called luciferase. But if you and here's the antibody eliminating it. But if you deplete that uh natural killer cells then the the antibbody uh loses it its efficacy. Here's the the treated with the antibbody but depleted with natural

killer cells. Tumas are still the same as the control. It's in two different models. So it's pretty strong evidence that the bicep specific antibodies working through the immune system. And finally, hopefully the perhaps the last point of evidence here is that when

we take tumors from men who had donated their body tissues to a rapid autopsy program at University of Washington, um Peter Nelson and Co Moresy collaboration we and and and you you combine it with data sets from other um

metastatic castration resistant disease or men who have had prostate cancer of early onset from this is data set from Germany men who had prostate cancer below the age of 50. You can see the very strong correlation of this integrant alpha V with the MC target

um which essentially is the point we're trying to make. Mick is at the heart of this basil aggressive phenotype and the alpha V integrant is a principle determinant of that MC signature. Um um and and so we come to a summary slide

here that really illustrates this paradigm of basil and luminal trajectories of prostate cancer. Um it's it's basically a recapitulation of normal development except in complete disarray because cancers are cells out

of position essentially. And what happens is that the the basil layer is supposed to differentiate into luminal cells. So this is true of the normal cell as well as the cancer cell. the stem cell the cancer stem cells that are basil- like will generate this and

receptor positive PSA response uh positive cell but if you treat with hormone therapy right uh intensified hormone therapy dropping the testosterone and blocking it and so forth you drive the composite identity of the tumor toward the basil the basil

phenotype right that's just the plasticity that we're referring to um and so these are very different biologies and I showed you the gene expression program. This is andigen regulated but as I as our research indicates the basil type is yap mic

regulated through that stiffness paradigm the mechano signaling paradigm and our biic antibbody reverses that in an immunogenic way meaning it sparks the immune visibility of these basil type tumors and brings in all these immune

cells to eliminate them. So this all that this is a sort of a simplified thing but what I what I said earlier was that tumors are an ad mixture of these two types of cells. So you have to think about you know combined targeting of

luminal directed therapy as well as basil directed therapy and I think that is the future uh where transformative advances in this disease may come from that is our that is our um conviction shall we say obviously it's our

conviction um but I do think the field will come around to it eventually um Ragav is my uh partner in crime in the laboratory. We've been together over a decade working with a fleet of other um MDs or MD PhDs or PhDs in the

laboratory supported by the National Cancer Institute. Um we're hoping the NIH will continue to fund our research. Obviously challenging times for researchers nationwide and we haven't wouldn't have survived I should

very proud to say we would not have gotten this far without the support of uh our amazing patient families and who have lost their loved one in the process of course sometimes unfortunately um and so I'm happy to talk about this

work or anything else you'd like to talk about thank you for your attention >> thanks for that overview. Um, I think I could almost follow half of the microbiology. So, and there's some more sophisticated people in our audience. Let me just ask a couple of questions

and then I'll read some of the questions from the uh chat as well as um um we can uh people can use the raise hand feature and ask live. Um Dr. Matthew, you know, we're we're patients and caregivers and so one of our questions is that's very

pioneering research that you're doing. when might it be accessible in a clinical trial or other ways uh for patients? When should we expect this to show up in places where we can take advantage of it? >> Well, I mean I wish I could uh say it

would be tomorrow. You know, uh we are anxious to get this into the clinic and the reason we think we can in the first place is we know this is a very good antibbody. uh whenever you're moving research from an academic uh s setting such as ours

into the clinic, you need to know things about pharma development of therapeutics that you perhaps wouldn't have known uh otherwise. And one of those things is how do you scale up things? Can you scale something up? Can it be made in in at volume? And does it have all the

characteristics of a good drug? And everything that we've done so far, which I haven't talked about, suggests that indeed this antibbody has a future. So that's point number one. Point number two is that we have to convince funding partners whether venture capital or big

farmer or small farmer to partner with us to develop this because we as a research university um cannot do this on our own. So Ragav Jooshi and I have formed a spinout company uh in order to enable that uh

you know progression to first in human trials. We obviously have to get permission from the uh from the FDA for an IND investigate a new drug application. Uh meet jump through all these hoops that they require to show that this is likely going to be safe described clinical trial. So there's a

lot that goes in. It could take I'm not sure uh how long but hopefully not more than a year to get this into the first in human trial. We certainly think the science is very robust. The antibodies very robust. We just need the dollars and the team around us you know to to

get it into trials. So definitely it's a huge priority for us. >> Okay. Um how would you how would you again from a patient's point of view uh they are you know let's say diagnosed they have a gleon score um and now

they're considering options radiation uh hormone deprivation uh maybe this treatment. How would you see it fitting in the I don't know the decision uh matrix of options and how would it fit and in particular I presume

you're acquainted with the work of Bob Gatenby. >> No. >> Okay. So he's someone we should introduce you to. He he uses language very similar to yours. He uses evolutionary biology >> and molecular models and uh mathematical models and game theory

>> to develop he's he's been active with bipolar androgen therapy for example. Mhm. >> Um and sort of you know sort of it's in the same way that you are sort of thinking about the molecular model >> and then you're inter you're intervening and how do you intervene with different options. So how do you think about that

>> kind of treatment options and maybe even combinations or things of that? >> Yeah definitely. Well certainly uh we we know having treated men with prostate cancer for a long period of time how much the treatment for the disease itself imposes suffering on men. um you

know whether it's the primary treatment of the gland and its impact on sexual or urinary function or the utility of hormones and all the impact it has on on libido and and skeletal and muscle health and so forth. So the questions we ask ourel is if our if our findings of

such primary importance and and we as we believe they are will they have a future in minimizing the impact of other therapies can we treat for example high-risk formats of the disease that haven't even spread yet with this antibbody with a short course of hormone

therapy to enable the immune system uh to to act on the tumor as it is in the gland without necessarily operating on it or radiating it that is a bit of an imaginative leap. I have you know I must concede that. Um but it it is along the

lines of what we must think of as a research community to make transformative advances in treatment. Clearly because we think our antibodies allowing the immune system to see and recognize and destroy these cancer cells. We can certainly combine it with

immune checkpoint inhibitors, a very established uh set of therapies in cancer biology that has not been effective in prostate cancer probably for the very reasons that I have illuminated in our discourse. So it is if we are essentially tackling the major obstacle to imunotherapy in prostate

cancers, I would propose we are then we may make a transformational advance in allowing immune checkpoint inhibitors to play a genuine and substantive role in controlling the advanced form of the illness but possibly even the high-risk localized forms of the treatment of the

treatment to minimize the impact of both local therapy and hormonal therapy. Mean me for example a short course of hormone therapy combined with a bicep specific antibbody and an immune checkpoint inhibitor that triple triple combination might serve to eliminate it's dual basil

and luminal targeting that is immunogenic meaning he's going to stimulate the immune system and then immune system can flood in there create that activity who knows if we will transcend the need for local therapy we're getting there in bladder cancer for instance we we we're combining

antibbody drug conjugates in imunotherapy and finding complete response rates and very aggressive organ confined bladder cancers in over 50% of patients and we're thinking about sparing the bladder. So it's not an it's not an outrageous idea by any means. So

uh I think that is the kind of future we do need to visualize. It does demand that kind of bold thinking. Obviously the science has to be rigorous enough to get us to that point but that is the direction in which we must try to navigate. Hey um Rick Davis has a question which

uh I have a variant on too but his question is in layman language can you translate this theory to clinical application does your antibbody address the yapmic pathway and what is it doing and I have another related question I think which is what's the me mechanism

like uh the mechanics of it when I hear bicep specific I hear latches onto you know PSA PSMA on one side and latches and then has a payload on the or grabs a tea cell on the other. Can you talk about sort of the mechanics? I think that's what that's what I'm curious

about and I think what Rick is asking. >> Sure. Well, >> sure. Uh I'm I'm not going to put up any more slides. I'll try and use words if that's okay because I I'll be hunting for slides and stuff. So, just trying to use my words. So, as I said to you, um in terms of the mechanism, how what is

this YAP mix stuff all about? Let me let me say that the basil layer the outer layer of the gland you know the one that harbors the stem cell is the one that anchors to the environment and we need these integrants to do that. integrants are they're essentially the

connecting you know connect connectors of the environment to the interior and when these are under tension the the whole phenotype of yap and mick is triggered okay um when they're soft remember how I showed you if it's stiff

you get a bone forming cell in in one context if it's soft so it's fate it determines your fate force determines the fate so this these integrants are are determining your fate because they're transducing this force Right? And so the force is what triggers

yap. Now yap is the central hallmark transcription factor of that force trans. You know yap is key to that. It's not the only one but for simplicity it is a major one and a deterministic one because what it does is goes to the nucleus and turns on the mix switch to

the max. You can dials the mick the volume up if you will without heat. the mick volume is it's not off completely but a low hum >> but when I'm trying for the right for the right uh the metaphor so it turns up

the volume on the mick and when the mick is up the immune system is absolutely shut down okay so this is how a tumor escapes immunity because mix volume is turned up to the max by yap yap is in there because his integrants are

signaling through force from the environment and that is the hallmark of these basil type cells that resist immunity, they resist hormone therapy, they resist chemotherapy, pretty much anything you throw at them except perhaps our antibbody or something like it that attacks the central identity of

the basil phenotype. And I would say there are very few therapies out there right now that actually do that. Most of them are targeting the luminal phenotype. And so you asked about by specific, how does it work? Well, it's an antibbody that targets these two integrants simultaneously. It is not

trying to recruit a T- cell. The bicep specific that recruits T- cell engage the T- cell engages is one end of the antibbody is connecting to a T- cell the CD3 and the other end of the antibodies connecting say a prostate cancer cell say PSMA

those are your bspecific T- cell engages for prostate cancer. One of them is a T- cell the other one's a prostate cancer. So we're not doing that. We're just simply going at the heart of the identity of the aggressive disease. And you have to target both those integrates. You cannot target one or the

other. Our research has indicated and you cannot use two separate antibodies because that doesn't work very well either because they found a way around that too. But when you use it in the bi-pecific configuration, you target both integrants in one molecule, the equation changes because this time the

integrants are now forced into the cell. I didn't I didn't talk about all of this, but it forces their degradation. It takes those integrants and takes them off the cell membrane, sends them into the cytoplasm to something called the lizoome, which is essentially a graveyard. It destroys it and the

enzymes that that that destroy them. And so this integrally shut down. This is what allows that whole force edifice to collapse. >> Okay. Um >> was that was that understandable? >> I think it was to me it was held Okay,

good. >> Um, I hope we'll let Rick be the judge. He has another question here. What's the difference between lumen A and lumen B? And why is there a difference different response to drugs? >> Yeah, that's that's an important question. So, you know, these further differentiations of luminal phenotypes,

one of them is much more responsive to the androgen receptor than the others. I haven't used that nomenclature for our work. we've just simply simplified it as androgen receptor regulated or not and in the architecture that we use whereas

luminal versus we use the CD49 marker essentially to define uh basil versus luminal um I think much more work is needed to be done to harmonize all these nomenclatures but for simplicity sake is something regulated by the androgen receptor or not uh and if it is not it

is almost certainly a basil phenotype and that's the type that I think integrans and YAP and Mick are playing the major role. >> Okay. Russ asks a question. Does this relate to the PCS class luminal D LPBN

BI is a higher percentage of HSPC man luminal >> in at presentation. I mean these are various there are various ways to skin a classification cat if you will and I our work has not addressed these variable

nuances across multiple laboratories and in fact these are not none of these are being used in the clinic in any substantive way as of this moment although there is a strong push to do that including bringing in AI programs to define you know what this phenotype

is and that's also under investigation but what I say is that when everybody when most people present with prostate cancer I would say 99% of prostate cancers at the time of presentation will have a antigen

responsive phenotype meaning you drop the andigens you will see the PSA fall you will see the shrinkage in the cancer um but you will not see elimination of the cancer there will always be a residual phenotype you know no matter

what description you call it, you know, all these various classifications, right? So, they have variable sensitivity to androgens, but no one of them will allow for a curative outcome. You may have long-term control, but you know, it is highly variable. And we've

not used any of these classification tools in the clinic to decide whether or not to treat somebody with hormonal therapy based on the probability of response because pretty much everybody does respond at least initially. So right now I have I can see just yesterday so two men both with very high

volume bone metastasis not different from what I showed you one of them who's been under years of control after hormonal therapy and chemotherapy and another who has who didn't even have a few months of control with treatment and the disease is already progressing and

there isn't any one tool whether you sequence a DNA mutation or um that's clinically available in clinical practice to differentiate these two we simply try and see what happens. So we take this dynamic approach where we treat patients and then we observe the PSA decline and if the PSA doesn't

decline below a certain level then we know we're in trouble you know. So we haven't used any of these tools to define our approach but what we think is behind all of this is a much simplified idea. We we're seeking to simplify and collapse all these complex architectures

into this driving uh you know phenotype of MCregulated basil phenotype that integrants control versus the luminal that andigens control. >> Thank you. Um MJ Qui asks what is your

spinout company called again? >> It's called Jolian Therapeutics. J O L I A N. It's a it's a C corp with Delaware. Thank you. Um Alan Morris has a series of questions very intrigued by the connection with bone

um and that the fact that prostate cancer metastasized in the bone. Why do you think that prostate cancer is not only bone centric but also osteoplastic not osteolytic? >> I consider this a medical curiosity. >> Yeah. >> This fundamentally suggests that osteoblasts are activated more than

osteoclass. Do you agree? >> Yeah, certainly. I mean in the osteoblastic I mean bone I didn't get into that short format lecture but um the the the osteoblasts are

actually I showed that force matters remember that force matters slide that was actually a precursor to an osteoblast placed in a stiff micro environment becomes an uh an osteoblast that same precursor put in a soft environment becomes a fat cell and a diposite. So in in in the uh bone

environment prostate cancer cells secrete things that excite and activate osteoblasts that's called paranoplastic effect and these osteoblasts cross talk with the prostate cancer cells they are integral to each other

uh in in the way they cross talk and enable each other's proliferation. So prostic cancer signaling to the osteoblast and there's a reciprocity coming back and what we find is that the same integrants alpha 5 and alpha v are playing a crucial role in the stroma in

the in the in the osteoblast as well and we've shown that in the paper which of course hoping you'll be able to read in uh and see it's one of our it's figure six I believe. So we show that this osteoblastic phenotype is also controlled by the dual action of these very same two integrants and we can shut

that phenotype off dramatically by combining these two integrant targeting. So in truth our therapy is targeting both the tumor cell and its immune evasive property as well as the enabling osteoplastic response. We see that as a

duality of which is the true identity of the cancer is this essential cross talk it has with its environment. We think that is the future of advanced cancer therapeutics where it is recognized that cancers as I said to you are non-random.

The non-random because there's a cross talk with the environment. At the heart of this lethal phenotypes of many cancers is what is the nature of the cross talk? What is mediating it? And we think that the crossroads of that are these integrants or similar paradigms to

be uncovered for individual cancers down the road. And I think that is that is actually a huge part of the story. So thank you for that question. >> Um I have a question about the diagnostics that might be associated with what you're doing. So that you know

a companion diagnostic often can predict people that will respond to this and it gets at the question also who is this going to be most useful for? Is this all prostate cancer patients high Gleason scores whatever. So can you sort of speak to is there a possibility for a

diagnostic that would be tracking some of these things associated with this treatment and who will it be ideally suited for? >> That was a fantastic question. I think um um this is something that we are we we believe we have different levels of

uh ideas about firstly we have studied the distribution the frequency of distribution of these integrants in primary prostate cancers is published data. we find very high expression frequency of these integrants are turned on in the cancer phenotype and absent in

the normal gland. So the normal gland other than the basil layer the luminal layer does not express the alpha v integrant at all. But as soon as you start to develop higher grade cancers it's turned on and it's at high frequency in metastatic disease. It's in 70% of bone metastases in the tumor

cells alone and in 95% of the bone vascule in tumor in tumor metastases and in the stroma. But it's also in other organ sites. So you could say that the frequency of it is high enough across all men with metastatic disease that one

might assume that it's a near universal phenotype if you have osteoplastic bond metastasis for example. But we also want to show that this integrant make association is a more precise way of of annotating a tumor's uh connection to

this uh phenotype. So that's a secondary layer. So one is a clinical if you see a clinical evidence of metastatic prostate cancer to bone almost certainly we think these integrants are implicated. But if you if you're not sure you have some intermediate phenotype for example we do

believe that the integrant mick transcriptional signature it's not something that's actually being studied so far and the many companies that will sequence your DNA for you whether it's foundation medicine or caris uh or gardens and so forth right that's what

doctors are ordering for advanced disease to look for specific mutations that are targetable but they do not have anything to do with what we believe is the foundational biology of the disease which is this integrant make association right that's actually not being

annotated so as a companion diagnostic I do believe this is something that needs to be developed we have actually uh talking to caris um about this collaboration um and it's something we want to develop of course they have their own business model and how they

want to do things so we have to you know get to that point but there's a pragmatic way of looking at it is that we believe it's a near universal phenotype for bone metastatic disease But in other contexts and obviously we're interested in other cancers as well will integrate make associations be

the calling card that is specific uh for this therapeutic and obviously when you go to clinical trials it's important to embed such ideas into those trials so that you can validate them further and are there that Alan Morris has just

on that point of other cancers besides prostate cancers where this might be useful or useful at modeling um he says In fibrosin cancers such as pancreatic and prostate cancer, TGF beta is considered pivotal. How does this fit into the YAP MC pathway?

>> Super question. Uh well, again, it's in the manuscript uh the citations are relevant, but TGF beta is a very important player in suppressing the immune system and cancers. Okay, it's princ TGF beta is does all sorts of

things. It does there's a long list of things it does to block CD8 cytotoxic tea cells uh from coming in. It brings in something called T- regulatory cells the ones that suppress the immune system. The one that won all the Nobel prizes in medicine last year. So TJF

beta brings them in. They suppress T- cell function. They increase something called macroofage polarization from M1 to M2 and so forth and so on. But TGF beta is sourced mostly from the stroma, not so much from the cancer cells. So your your colleague mentioned fibrosis

meaning scarring that is all about that stiffness I was referring to. So those tumors that are scarred and have high tension have a lot of TGF beta and you know why because they require the integrant alpha V on these stromal cells

to process TGF beta from its inactive latent form complex with a latent peptide. When there's traction on it it activates the TGF beta. releases it from its latent peptide and it's now activated. So stiffness in the stroma

activates TGF beta and alpha V is key to that and what we show in our animal models is that in the tumors themselves when they implanted into the mice TJF beta is strongly downregulated with the bispecific antibbody. So when we think

about I didn't mention this because the sake of simplicity I talked about Mick alone but we're actually targeting three major pillars of imunosuppression MC TGFBA and one a third one called EMT epithelial messenymal transition these

three are strong stem cell immunasive signatures that are used by a host of malignancies and again I think these two integrants have a lot to do with it across a wide variety of cancers largely because they are recapitulation of what

I call embryionic phenot integrants. These integrants are key to embryionogenesis. Um you know you mentioned somebody with an interest in in evolutionary biology. Now integrants are ancient things by the way the person who discovered integrants

and fibonnectin Richard Hines only passed away just last week um MIT professor and obviously a legend and on whose broad shoulders we all stand. Um so I really attribute thanks to him we have all of this narrative to talk

about. Um but any rate EMT or EMT is from Bob Bob Bob Bob Weinberg that he was the one who discovered that at at the Whitehead Institute and taught us about that. Um but at any rate these three are um u major imunosuppressive pathways have a

lot to do with these two integrants and specific there are many integrants and there's a lot of skepticism about the integrant field by the I should I should hasten to add because people have been studying them for a long time right but why hasn't there been advances in the clinic why I would say the following is

because of the interaction between the integrant alpha 5 and alpha V and the absolute necessity to target the both of them with a very effective modality such as a bicep specific antibbody is key to the failures of the past if they studied

only one integrant targeting and the other one is robustly compensating you're not going to get anywhere where in fact you could accelerate the disease by targeting one one because the other one rears up and says you none of that's going to happen under my watch and sort of ampl ramps up and sort of can even

increase bone formation. We can see bone formation increasing if we block the alpha v integrant without blocking the alpha 5. It's very interesting. So they really have a robust cross talk and all the therapies of the past have targeted only one or the other.

Just a quick question on plasticity. Um I ran into a company that's building a diagnostic apparently. Uh as as I understand it, uh before a cell can metastasize, a cancer cell can metastasize, it gets soft.

>> Oh yeah. >> And you can measure the softness like you can poke the cells and measure the softness or firmness of the cells and then tell whether it's about to metastasize because I it's like it has to get out of a go through a great sauce so it can fit through and get and metastasize. Have you heard of any of

this? The company's name is Art Artitus. >> No, I haven't. But uh I >> Do I get a receipt? Are they silly? >> Sorry. >> Yeah, I I I I it hearkens to a concern that we had which is cancer cells use

integrants to anchor themselves, right? And so they establish themselves say in a metastatic niche. We call that the niche, a special sanctuary site where cancer cells can hide and establish their survival and evade immunity. So they're there sitting in dolmancy.

Say you take out a high-grade glyon 9 prostate cancer. You've had surgery. Your PSA is undetectable, but there's a risk that the cancer cell is out there somewhere. You can't see it. PSA, you know, uh but it's there in dormcancy. So you come in with your intermittent antibbody and release it from its

dormant state. Now it's going to do what? get back into the circulation and start circulating and causing metastasis. This is the theoretical concern which is hearkens back to softening the cancer cell and allowing it to metastasize. Right. So could this be a protastic

treatment rather than an anti-tastatic treatment paradoxically because of the softening response that you recommend that you referred to? But the point we would make is the softening is tied into visibility by the immune system so that the natural killer cells will say there

you are you know and eliminate it. So we not we we don't think this is going to be an issue at least that's not what the science is pointing to even as that concern that you raised comes to mind. >> Okay. Rick Davis has raised his hand.

Rick. >> Yeah. Thank you very much Dr. Matthew. I I'm not a biologist. I'm not even a scientist. So, my level of understanding is not great. And one of the things you've done is really shaped my um

perception of basil and luminal cells. Cuz I always thought basil cells were relatively good guys and luminal cells were relatively bad guys. But now what I'm hearing today is that no, basil cells are the root of all evil in terms

of um being nonrespondent um and and um a cornerstone of uh of castrate resistant >> prostate cancer. And I just want to ask

you a little more about that. Um uh uh uh should should science be focusing more on basil cells as being the bad guys and not luminal cells? >> Well, I I mean I I want to say that yes

and no because I think it's if you target only basil cells the luminal cells will now drift towards the basil and and make up for that gap or if you you target only luminal as we already discussed basil will dominate. So the idea should be yes we must focus on on

basil cells but we must think about com combinations of the basil and luminal phenotypes rather than just one or the other you understand. So if you think about PSMA now which is all the rage for plto and all the bicep specifics or the

newer fangled ones like the androgen receptor degraders or the new antibbody drug conjugates many of them are focusing on luminal markers almost none are focusing on basil def defined markers. So you're sort of seeing a polarized research clinical research

industry working towards hammering away at that PSA which is fine because that is a bulk of the tumor and you can get space right you can even prolong life but you're not going to cross a the at least in my mind a transformative boundary that is defined by that basil

phenotype that resists the immune surveillance. I think if you really want to get a crack at a big-time impact on this disease, we've got to combine both ideas in in something that's tolerable, minimally toxic, has a min, you know, minimum impact in patients quality of

life and a transformative effect on long-term outcome. >> And that PSMI PSMA is that um created by the luminal cells or the basil cells? I mean it sits on the outside of the

>> of the cell. >> Yeah. It's principally >> the prostate cell. >> It's principally a luminal type marker. Right. So if you see patients who have very low PSAs with metastatic disease oftent times a PSMA scan which you can image the disease but using >> right

>> is very weak or almost negative >> and you almost have to use something called an FDG PET scan the conventional PET scan for the cancers to see the to see that aggressive phenotype. That's really what we image as the basil phenotype that is weak in PSMA and very strong in FTG pact that is the most

extreme almost becoming the neuroendocrine prostate cancer right because a neuroendocrine pro small cell pro which I haven't talked about those are birthed from the basil phenotype they come from that basil phenotype they arise from that they drift off into

their own trajectory with these neuronal type programs which are also evading immunity but ticking over very rapidly and spreading to different sites like the liver and and causing litic rather than osteoplastic bone metastasis and sometimes even brain metastasis and so

forth. a very diff difficult customer also very immun evasive but at the heart of that is the a mick variant the nmick as opposed to cmick so there's some kind of a c to endmic switching that goes on to the neuroendocrine which makes a lot of sense when you in terms of a logical

thread of evolution from basil to to neuroendocrine also so I'd like to wrap up the recorded part of this session but always like to give uh you an opportunity to give a final parting words of wisdom or a summary,

key messages, anything you'd like to leave us with? >> Yeah, absolutely. I think the revised way to think about personalized medicine in prostate cancer specifically is sequencing the genome, right, isn't

telling us how the cancer is behaving. It doesn't explain the cancer's behaving, how the cancer is behaving. But by thinking about them in basil and luminal trajectories and understanding what defines basil and the central role of integrants in that that defines the biology. And what happens is all these

mutations whether it's p-53 or p10 the bracka even they converge on these integrants in diverse ways to to to explain the disease phenotype. So we need a new paradigm of thinking of combining basil and luminal targeting

for the reasons I've explained and a new way of thinking about personalized medicine beyond genomics sequencing alone.