At the Young-Onset Colorectal Cancer Center's third annual Patient and Family Forum, a Research Keynote lead by Jonathan Nowak, MD, PhD and Benjamin Schlechter, MD, discussed immunotherapy and CAR-T cell therapy in young-onset colorectal cancer.
Hi everyone. My name is Kim Yang. I am the director of the young onset colorectal cancer center here at Dana Farber Cancer Institute And I'd like to thank you so much for joining us tonight for our third annual patient and family forum. This is our research keynote which will touch on the very important topic of the role of the immune system in treatment of colorectal cancer and what is on the horizon for immuno therapies for patients with colorectal cancer. I wanted to remind you that if you have at any point, any questions that pop in your mind, please feel free to type them into the chat box. Don't use the Q and A box but use the chat box and we will be sure to address them after each of our speakers present at this time. I'd like to first introduce dr Jonathan. No ac. Um If you could please just give a brief introduction and then I'll let dr selector introduce himself and then we can get started. Everyone. Thank you for the opportunity to participate in this evening's talks. Um so I am a gastrointestinal and molecular pathologist at the Brigham and Women's Hospital. We'll talk more about what that is in just a moment. Um but I also helped to run a laboratory at the Dana Farber that is focused on studying colon and pancreatic cancer. Um Mostly studying specimens that come directly from patients and in that capacity I worked very closely with Dr Ng and other oncologists in the GI cancer center at the Dana Farber and I'm excited to share some of that research with you this evening. Thank you so much for being here. Dr selector. I am Ben Affleck to one of the medical oncologists here in the jeon ecology group and I work with Jonathan with kimmy. Um My main focus is on colorectal cancer and my effort re lately has focused on trying to identify new targets for therapy new investigational products and drugs um with the help of work done by Jonathan and others to really what we can do to help this this important disease. Thank you with that. I will pass it over to Dr Noah okay thank you so much. Um So I think we can move to the next slide. So I do have research funding from several companies that produce laboratory instruments that I should disclose. Although none of that is directly related to what will be speaking about today. Next slide. So as I mentioned I'm a pathologist which is a type of doctor. Not very many people are familiar with. Unlike oncologists, I don't directly interact with patients. However, I do supervise the laboratories in the hospital that generate most of the information that guides patient care. This includes testing things like blood or fluid specimens and it also includes examining all tissue specimens that are removed from patients including for example polyps that are removed during colonoscopy and colon cancers that are removed during surgery and all these specimens are sent to the pathology department where they are carefully dissected and processed to make glass slides that can be examined under a microscope. As you can see on the left, the picture on the right shows a typical colon cancer Under the microscope. This entire picture is less than half a millimeter across. It's truly microscopic and this slide has been stained with two chemicals, one that makes the nuclei or DNA containing regions of each cell blew, another that makes the rest of the cell pink. Next slide, so we now have some yellow arrows that highlight the colon cancer cells themselves. These are the cells that have mutations and are not a normal part of the colon. As you can see, they grow in complex ringer donut shaped structures called glance. And if we had an image of the normal colon seen under the microscope, it would look completely different in the past. Much of oncology and pathology focused on the nature of these tumor cells, figuring out their behavior, what mutations they have, where they might spread in the body, essentially. Anything that we could study about these cells, we would. But if we pause for a second, it's clear that there are actually many other cell types also present in this image. As a pathologist, I can tell what many of these are by how they look, but for our purposes, let's just say that they aren't tumor cells and it looks like there might actually be more of them than the tumor cells themselves. Next slide, we now recognize that there are many different cell types in the so called micro environment of a tumor and this cartoon shows some of the most common types. Pink are the cancer cells themselves. The roadways that crossed this image are blood vessels that have been recruited to grow into the tumor to provide nutrients. The tumor mass itself is surrounded by cancer associated fibroblasts or calves that produce extra cellular matrix, which is like a scaffold that holds it together. In addition, there are numerous immune cell types present, including B and T lymphocytes, macrophages, NK and NK cells, NK T cells and dendritic cells. And in this cartoon those are purple, green, blue and orange and you can see them scattered all about and it's these cells that will be the focus of the rest of the talk. Next slide there are coronavirus era. We all have some understanding that the immune system helps our body defend from things that are not supposed to be in it frequently. These are infectious agents like bacteria or viruses, but the same principle also extends to cancer. And although the immune system is rather complex, we can very broadly think of it as having two different parts and innate immune system that can be fast and an adaptive immune system that is often slower but has the ability to learn to recognize new foreign material and then destroy it when it's seen again, weeks or months later in the body. Oftentimes these responses require multiple immune cell types to work together. Next slide, one of the major focuses in my lab is studying how immune cells interact with cancer cells. And we do all our studies directly from human tissue specimens, just like the ones that we view using the microscope. In the past, we would have spent a lot of time carefully describing the immune cell patterns that we see under the microscope. Um but this is really a very slow process and it's really very tedious to count individual immune cells. However, recent advances in computing power make it possible to train computers to do this work for us. And an example of our workflow is shown here. This is a complex diagram, but the point is that we can start with an original image like that shown in the top center and analyze it using different computer programs to detect and classify cells into different types and also to define different tissue regions. This is accomplished by artificial intelligence or more precisely supervised machine learning. Next slide, now that we've gotten a trained computer to actually find immune cells. What can we do with those results? There's actually a number of different ways that we can process that data first. We can find out how many immune cells of each type are present. We usually do this by calculating a density or the number of cells per square millimeter of tissue. We can also look at ratios between cell types. Maybe the density of immune cells A. Isn't as important as the relative level of immune cell A. Two immune cell B. We can also look at where immune cells are. Are they within the tumor epithelial regions where they can directly interact with tumor cells? Or are they located at the edges of the tumor? We can measure this by looking in different tissue compartments and we can also measure the proximity or how close you are cells are to immune cells. Next slide, here's an example of what our data looks like. In this analysis, we looked at lymphocytes which are part of the adaptive immune response and neutrophils a component to the innate response. We did this across nearly 1000 colon cancer specimens. The plot on the bottom shows that lymphocytes are more common than neutrophils. And we can see this by comparing the line in the middle of each blue box and then looking down to figure out the overall cell density. However, both neutrophils and lymphocytes are much more common in the stromal region that surrounds the tumor epithelium than within the tumor epithelial regions themselves. These plots also show that there is a lot of variability between us. For example, some cancers have more than 1000 lymphocytes and neutrophils per square millimeter. Well, some have 100 or fewer. Next slide are these differences in immune cell content actually important. One common way to answer this question when studying cancer is to see if something is associated with patient outcome for survival. To do this, we took our 1000 patients and divided them into four groups. C1 through C4 based on the lymphocyte densities. C4 in red had the highest density, while C1 had the lowest density across these four groups. We then looked at the rate of colon cancer specific survival over time. Starting from when these patients had their teeth removed during surgery, all the lines go down over time, unfortunately, indicating that some patients in all groups developed recurrences and eventually died. However, it's also clear that patients with the highest density of lymphocytes did significantly better than patients with the lowest lymphocyte density across all years. They simply had a higher survival probability. Overall, these results suggest that having more lymphocytes into is a good thing. We next looked at our neutral film measurements and performed the same type of analyses separating patients based on high and low densities and even the neutrophils are very different than lymphocytes. We overall found the same results, patients with tumors that had more neutrophils tended to survive their colon cancer longer. Next slide, in addition to looking at immune cell density, we looked at how close lymphocytes and neutrophils are to tumor cells and whether this might also influence survival as the cartoon on the left shows. We do this analysis by drawing circles around each cell and then counting how many immune cells are inside the circle the plots on the right. We have now broken our 1000 patients down into four groups based on whether they have immune cells far away from tumor cells in C one or near tumor cells in C. Four in each category. We looked at the risk of dying after colon cancer surgery. And for this measurement, termed a hazard ratio, A lower number means better survival. And we found that in both the lymphocytes and neutrophils analysis, hazard ratios decreased as immune cells got closer to tumor cells in general, the US with immune cells right next to tumor cells have the best survival. Next slide how about some other immune cell types? There are more than a dozen of these cell types and many of these immune cell populations can be subdivided even further. Well, we can identify some of these immune cells just by how they look under the microscope. And we can even teach a computer to count them. There are only about four immune cell types where this is possible. We just can't really tell the rest of part based on how they look. And in some cases it's possible to take tissue and essentially dissolve it to release all of the individual cells which can then be analyzed in great detail. However, it's not really possible to do this for hundreds or thousands of patients, additionally dissolving tissue throws away all of the information about where cells are located, which we know is important. What we really needed was a way to work with intact tissue so that we could see cell organization but also find all of the hidden immune cells next. And to do that, we turn to a special type of camera in most cameras, such as the ones on your phone and also in our eyes or that Essentially work in a similar manner as our eyes. There are separate detectors designed to identify three main colors red, blue and green. However, cameras don't have to work like this. It's also possible to build them to individually detect many different colors, including infrared and ultraviolet light that's invisible to us. And if we click once, I think the next part of the side will come in. And so that's shown on the bottom here. That compares this approach with the standard camera on top versus a camera that can look at the whole spectrum of colors, I would just say as a side note, this type of imaging is now used in hundreds of labs all over the world, but was partially pioneered here at the Dana Farber and so by attaching the cameras on the bottom of the slide to a microscope, it's not only possible to see a larger color range but to also see more colors when they are blended together by adding mixtures of different colored chemicals that are each designed to detect certain immune cells to our slides. We can see whether the markers are expressed in the same immune cells or in different immune cells. Next slide. So here's how this looks in practice in our cartoon of the tumor and micro environment on the left, tumor cells are in pink and T cells are in purple. On the right is an image of human colon cancer. Where we've used chemicals to turn the tumor cells red and the T cells purple. Other cell types still have a blue nucleus containing DNA but they're otherwise black. Just as we did with our standard microscope slides, we can make digital images of these slides and then train a computer to recognize and classify every single cell and where it's located. Next slide this diagram provides an overview of how we use this technology to study colon cancer. Instead of starting with 1000 slides that each contain one patients. We make specially organized slides that have up to 100 on a single slide. We can then stain these slides with up to nine different colors and take pictures of them. Using our multi spectral camera. We can then train a computer to separate each image into regions of our cells and surrounding stromal cells to find every single cell. And then finally to perform phenotype ng or classification of those cells into different categories based upon what they're expressing. We can then use these data from immune cells for the different types of analysis that we talked about a few slides ago, for example, measuring cell density in different parts of the You can also see whether these densities or other features predict survival or correlate with other features of the next slide here are some example images from an experiment we did to look at different types of T cells. In this experiment we combine six different markers. We start by testing each marker on its own using a brown stain before assigning it to a color and making sure that we still see the same patterns of staining with the color as with the brown stain. The grid on the right shows six different types of t cells, each characterized by different marker combinations. Metro highlights a single cell and each column represents a single marker by looking at the different combinations of markers in each column. We can figure out what each cell type is. The column at the far right is what our camera sees and then breaks down into each single color column. Next slide we know that there are many different types of t cells in the colon cancer micro environment and in other we also know that in general having more T cells is a good thing in a tur however, t cells do several different jobs and it wasn't really clear which ones were most important in which ones really impacted survival. To figure this out. We used our cohort of 1000 patients and identified many different T cell populations using our different market combinations. As shown here, we measured their density in both tumor and stromal areas and then asked which populations were associated with survival. There's lots of information in this table. But essentially we're looking for the T cell population with the lowest number associated with it. And then if we click again, we can show that we can use some additional math to figure out of all these populations which one is really the most important. And that turned out to be a type of T cell called a psycho toxic memory T cell. These are T cells that are designed to directly kill tumor cells and their memory T cells because they have previously been exposed to a tumor or a part of it and have learned to recognize it and around the hunt for additional tumor cells to kill. Next slide here are some survival plots, just like the ones we looked at earlier, where patients are divided into four groups based on how many sided toxic memory T cells are in there. Red is the highest number in blue is the lowest for both colon, cancer specific survival and overall survival with the highest levels of cida toxic memory T cells are associated with longer survival. Although these side of toxic memory T cells are a small subset of all T cells in the tumor, much less all immune cells. It's really this specific population into mirror areas that is important for predicting survival. Next slide. While t cells are some of the most important and best understood immune cells in the cancer micro environment, many other immune cell types are present as well. We therefore designed experiments to identify these other immune cell types so that we can see them using multispectral imaging and measure them just like we did for T cells. Our ultimate goal is to be able to identify every single cell type, immune cell or otherwise in the tumor micro environment so that we can understand what role they are playing and helping the team for fighting it. If we can understand what cells are important and what they're doing, we can then develop better therapies that can target these specific cells and functions. And dr selector will speak more on this in a moment. Next slide in closing, I wanted to share some very recent results of our analysis of the anti tumor immune response in young onset colon cancers. The group of 1000 colon cancer patients that I mentioned a few times comes from two large studies that have been led by Harvard since 1970s and 80s. These are the nurses health study and the health professionals follow up study that have followed more than 170,000 men and women across the us to understand risk factors for many diseases. My collaboration with Dr XU T. O. Gino at the Brigham and women's hospital. We work to analyze all of the patients in these cohorts that have developed colorectal cancer. In total, there are more than 4600 such patients. For about 1500 of them we have tissue that we can analyze while these patients develop colon cancer at a broad range of ages. Some did develop it young and we decided to compare the young patients to the older patients. Next slide we did this two different ways. First we looked at the general patterns of lymphocytes in the tumors. Using standard microscope slides, four different specific patterns have been recognized in the past has shown in the blue and pink pictures on the left. These include clusters of lymphocytes at the very periphery of where they may be growing and expanding immune cell memory as shown in the upper left or bands of immune cells at the very edge of the tumor, as shown in the upper right, immune cells that are spreading around and in between individual glands as shown in the lower left and then finally immune cells that have crawled right into tumor epithelial areas where they're directly touching tumor cells. As shown in the lower right. And we also used our multi spectral imaging essays to measure immune cell identity focusing on t cells. Macrophages and myeloid cells. Next slide, We started by comparing patients less than 50 to those 55 and older surprisingly, we did not find any differences in the types of immune cells that are present. Young and old patients have about the same number of various types of T cells, macrophages and myeloid cells. However, we did see differences in where immune cells were located. In particular. We found fewer us that have high levels of including infiltrating lymphocytes in young patients compared to older patients. In short, this suggests that young colon cancer patients are less likely to have lymphocytes touching or very close to our cells. Since this is what lymphocytes especially t cells need to do to kill the tumor. Our results suggest that this response may be somewhat impaired in young onset patients. The circled P value here suggests that this wasn't due to chance, but we don't yet know why this association association exists. It gives us some guidance about therapy development. For example, we wouldn't necessarily need a treatment that drives more immune cells into a more of a young onset patients. They're already there. The problem is that they're avoiding the tumor cells perhaps because they're being repelled or because they don't recognize the tumor cells and we might want to fix these defects in different ways. Next slide, all the work that I've presented today has occurred in research labs where we study tumors from patients that develop cancer years in the past. However, the technologies that we use are starting to transfer over to the clinical laboratories that perform routine patient care immuno profile is one of these efforts. This is a joint collaboration between the dana Farber and Brigham to perform immune cell profiling at an enterprise level or in other words, across many different types to process and manage this massive amount of data. We built a completely digital workflow that allows us to remotely view and analyze images and write reports. This work is now done in the Brigham pathology department is shown in the lower left with one of our laboratory technicians operating a slide scanner. Next slide, it was like in our research lab. We use multispectral imaging and machine learning to analyze key immune marker expression. We have five different versions of the essay that can together together analyze most types of solid. This was launched in 2018 and has been ordering ble by clinicians for the past year. And although our results currently go to a special viewer accessible in the medical record, we should be able to eventually report these as standard clinical results. The plot on the right shows an analysis we did for the 1st 2000 tumors that we analyzed. There were many different types such as colon, lung, breast and melanoma. Each tiny column is a tumor in each row is an immune cell marker Grouping. These 2000 us based on how similar they are, shows that there are five major patterns of immune marker expression that we can recognize. Some tumors are cold or harbor few immune cells. While some are hot and harbor many immune cells. They're also distinguished by expression of PD L. One, a very important immune cell regulatory marker. The very bottom of this plot shows the ages of all patients whose tumors were analyzed. In addition to studying the immune response in young patients with colon cancer. We can ultimately use these data to study all types of young onset cancers. Perhaps there's a common theme in the immune micro environment of these young outside cancers that occurs across tumor types. Excellent. So in closing we've discussed that immune cells are a major component of the colorectal cancer micro environment and we've seen some examples of how their abundance or density and their spatial organization can actually predict survival and outcomes. We have noted that interactions between lymphocytes and tumor cells may actually be altered in young onset colon cancer patients. And we finally touched upon the ways in which this sort of approach and digital imaging could actually be a routine part of clinical care in the near future for patients. So thank you. Thanks. That was super fascinating. Um so now I want to talk a little bit about what we can do with some of this information that we have learned a lot about the cells that are present, How that can predict outcomes. The question is, can we manipulate this next slide please. So I have nothing to disclose the relevant. So the immune system's job fundamentally just in a really simplistic way is to identify things that are different from normal tissue. And so um this system protects us from everything from infections to inorganic matter like dirt and debris and it's meant to protect us from cancer next slide. Um and I guess the fundamental question is can we harness the immune system? Can we take the work done by Jonathan and others and see if we can do it? What we have learned over the past two years is that yes, There are fast and effective ways to harness the immune system. I think one of the great successes of modern medicine is actually the vaccination against COVID-19 and we've seen real successes in identifying a really different marker and priming our immune system to fight that to prevent injury and prevent transmission of the virus. Next slide. Unfortunately, cancer isn't quite like a virus and cancers are quite like infection. Cancer is much more an altered form of self. So while those immune cells may be present and their potent and important immune cells, they lack the ability to realize what's going on. Next slide. So I think of this as a counterfeiting problem. If you look at these $100 bills here, they, to me are essentially indistinguishable. Maybe one a little bit darker ones a little bit later. And when I took a little quiz on counterfeit $100 bills, it turns out it wasn't so good at identifying them. Excellent. This is the problem that human system has with cancer cancer is derived from us. And as a consequence even the most um infiltrated with many, many immune cells may not actually realize what the problem is to be able to attack it. Next slide. The other reality of what we're facing when we're fighting cancer with immunotherapy with the immune system is that cancer can fight back. We hear a lot about PD one and PDL one. I think it's important to understand what those represent. These are markers that are here to regulate the immune system. And so by triggering PD one with Pd L one engaging PD one that does something important. Next slide. Mhm. So every time we get an infection are T cells expand and if we did not have a way to turn off our immune response response. By the time we're about three years old, we would need a mac truck to carry around our immune system would expand and expand and expand. The other challenge with expansion of immune cells is they clog things up. This was the clogging of the of the Suez canal earlier this year with a tanker full of stuff. Things that we wanted. Iphones and microchips. If we could not suppress the immune system in a normal fashion, if we could not regulate the application of immune cells and the maintenance of immune cells, they can become a huge problem. And this is one of the challenges of offering immune therapies to patients. We don't want to generate these problems. Next line. I mean therapy in cancer has become a huge deal between 2011 and 2014. These were some of the most important innovations and cancer. These were cover articles for important journals like science and nature and the New England Journal of Medicine that we hear a lot about. But one of the challenges has been really a limited response in colon cancer. It's been frustrating and it's been really inspirational to try and find a way around this next one. So stepping away from the immense for a second, I want to talk about the treatment and how I personally would break these down. I think everyone can sort of design the chapters of me in therapy themselves a little bit differently. There are drugs, some of them are older drugs that generate inflammation. Can we give you give a patient an agent that will set off an immune response within the tumor micro environment, the most common one to know about Interleukin Two. Then there's the checkpoint inhibitors. This is these are the blockbuster drugs of the last decade. These are the checkpoint inhibitors, the pD one against four and so forth. The challenge with these. These are non targeted treatments. When you give a checkpoint inhibitor, if a cancer is using that marker to suppress the immune response, you may be able to turn on the immune system in that environment. And yet the tumor cell of the T cell rather may still fail to recognize that that is a is a different cells that is a foreign cells and attack it. And then finally, I think we start thinking about targeted immune therapies and these come in a bunch of different types that we're going to talk about shortly bite cells, modified T cells, truecar teas and tumor infiltrating lymphocytes, which are kind of in their own category on their own next line. So one of the great successes of checkpoint inhibitors and colorectal cancers and the rare subtype of mismatch repair deficient colon cancer and advanced diseases maybe accounts for a third of all colorectal cancers. And not only do these work, but they work in a durable fashion. So checkpoint inhibitors when given if you look at this on the right side of the screen, which is, he's a swimmer plot the blue bar is the period of time that patients were on treatment and the green bar is the period of time with benefit from treatment. And so it turns out that not only in this rare subtype of colon cancer can we generate an important immune response, but the immune response persists. And so this tells us about the memory of the immune response and the way the immune response can generate persistent and durable immunity against cancers. Unfortunately, this is not the common type of colon cancer. In fact, it's very uncommon to colon cancer. Next line. Really important effort was undertaken to look at the combination of immune therapy modern immune therapy with checkpoint inhibitors combined with the conventional chemotherapy that we would commonly give for the treatment of colon cancer. And this was a very exciting study. Was very important study that very quickly enrolled and every one of the clinical trial received standard of therapy, standard of care chemotherapy and half or two thirds of patients rather received the checkpoint inhibitor and volume ab unfortunately there was no benefit to the combination. So for standard risk for microsatellites table colon cancer, the combination of chemotherapy with a vegetarian skepticism plus the volume at was no different than conventional chemotherapy alone. So this is a real disappointment. Next slide. So I think what we should talk about is some of these targeted therapies. Moving away from checkpoint inhibitors. Think about where we can move next and we can talk about the different subtypes. So bite cells. So bite cells are an interesting idea and I think they have, they have a future in the treatment of cancer. This is a situation where you generate a protein in the body, where one side of that protein links up to a target, let's say a special type of colon cancer with a target you can identify. And the other side of the antibody links up your cell, your, your cancer cell to another cell, like a T cell or one of these more innate cells like a natural killer cell. These are sort of generic infection fighting cells. And so maybe by pulling these two cells together being in the same environment that can generate an immune response against the cancer. There's a whole class of modified T cells that can either be engineered or altered in some way. And they don't necessarily have a name person, I'm gonna call them T. C. R. S. And this is where you identify a target. You know what you're looking for And you can convince your T. Cells to to stick to that or attack it without generating sort of a major alteration in the function of the T. Cell. Car T. S. Our cars, our T cell that has a target just like the others but it's inherently active. So we can't exist with our T cells active all the time. It gets sick. There'd be too many of them. They would they would expand, they would divide that would cause the problem like the Suez Canal and they would generate inflammation. They would give us fevers and all sorts of side effects. So car T. S. Are engineered to set off that response to set off that bomb of the immune response when they're engaged. And as a consequence they're active we don't have to worry about them becoming active but they can also cause them trouble by their activation. And then one of the final really interesting targets for treatment in the future is looking at um are infiltrating lymphocytes. Can we look at the data from Jonathan and others identify the cells that are inside of a tumor that we think are most likely to generate benefit remove them from the cancer from the patient rather through surgery through a biopsy expand them in some way and infuse them back in a way that's safe and effective. Next slide please. I think it's important also understand how long it takes to do this. These are not fast treatments. Almost all of these require some sort of marker. So we need to identify what we're going after. What is it about this cancer cell that we can target. And that requires a screening process. We take an existing biopsy we test it either in a central lab or locally for the target. We're looking for. Once we're sure that is present, patients have to undergo what's called an apheresis process apheresis collection of T cells or any other immune cells from your blood. Often that requires placement of central line which is a very very big ivy in your neck. It can sometimes be done through I. V. S in your arm. It can't be done through a port a cath which is one of the more challenging issues for colon cancer patients. Porta Cath needles called Huber Needle has a 90° turn and you can't run blood through it very very quickly without injuring the blood supply. So as a consequence specialized these are required to do this. The blood is taken from the body of the patient has run into a machine almost like a dialysis machine or a blood donation machine, cells are separated out and the blood is prevented from clotting by removing certain salts of the blood in particular calcium. Then the blood is given back without the T cells. It only takes a small fraction of your total T cell volume, but it's enough that we can generate the product when the blood returns, you can have a little calcium in your blood and you can feel a little sick from that for a few hours and we can fix that with calcium supplements. Once the T cells or targets cell are extracted, they're sent to a manufacturing procedure and that can take several weeks to do where the cells are infected with a virus or altered in some way or exposed to some marker to generate the self pride that we're looking for. And once that's been successfully done, a patient is brought back to the hospital and we give what's called limbo depleting chemotherapy. This is a critically important step in creating an environment where we can give the T cells safely. But we can also create space for the T cells. The Lincoln depleting chemotherapy is generally 1 to 3 days of a drug called food therapy in with another drug called cyclophosphamide. There's some nuance there in every version will have a slightly different combination that does cause normal cells as well as existing key cells to be injured And that's what leads to some of the risks of these procedures. Once lived with the chemotherapy is done in general, patients are admitted to the hospital for careful monitoring and the T cells are infused depending on the product type. It can be once two weeks in the hospital maybe less, maybe more. And one of the great areas of research is finding ways to do this as an outpatient without requiring hospitalization. The reason for the admission is partially from the limited cleaning chemotherapy. We're giving you chemotherapy to suppress the normal T cells and create space for the new T cells that suppresses all the blood counts. And so does the risk of infection and bleeding. Like you would have from any chemotherapy when those T cells arrive in particular. True T. Cell and activated T. Cell, they can generate a tremendous amount of inflammation that has this term cytokine really strong that we've heard spoken about a lot during covid in the early in the early onset of the covid crisis. This is where patients are very very high fever and low blood counts and they can get very sick. We have these very strong medications to block that and we can give medications to raise your blood pressure and to prevent injury from the side of the storm. One of the consequences of that inflammation is actually a very unusual side effect of people getting very confused, very sleepy called neuro toxicity. We have to act very quickly to prevent that. We don't want to see this in patients and if we see it we need to act so they don't get sicker. And that's one of the other reasons you need to be in the hospital for these treatments. Sometimes the target of the T cell is an issue. So for example, if the target is on the colon cancer cell but also somewhere else, let's say the heart need to monitor for injury to the heart. And so we have to be very careful target selection and sometimes there's delayed problems. Um the immune system ramps up over time and may generate a problem later or the key cells themselves misbehave in some way because they're engineered to grow and they may keep growing without without proper control. We have to suppress that there's a period of time after T cell therapy like a car tear and engineered T cell where we watch patients extremely closely, especially in the first month and for those first three months and after a certain point in general the treatment has taken its effect is going to work. It's not gonna work. It's a one time treatment and should have persistent efficacy and memory against the cancer. And once you've completed that very close follow In general, you go off of one clinical trial and onto another for follow up. So we have a period of time for close monitoring and engagement and a second clinical trial is purely for the purpose of long term monitoring for friday of reasons. Next slide. So we're going to talk about some of what I think are the really interesting trials that we're doing right now here at Dana Farber and using cell therapy. If we have time, we can maybe talk about some of the non cell therapies. So one of them is a drug company called Triumph era. They have a product called tactic to this is a T cell directed therapy against her to the next slide. So her two is a common marker. We see it throughout the body, exists in the lung, we have it on our heart, it's very, very commonly amplified this extra copies of it and breast cancer. And it turns out about 5.8% of colon cancers are heard two amplified that's enriched in patients with left sided colon cancer, colon cancer of the sigmoid colon and rectum, which are more common in young onset colorectal cancer. There are also her two mutated cancers or her two cancers that are a little bit over expressed genetically. Those may or may not be candidates for treatment like this Because her two amplification is very strongly expressed. It's a durable target. It doesn't go away. It makes it a good target for T cell directed therapy. Um The other issue we have to be aware of course is that her two is present on normal tissue like lung and heart. So as a consequence this is a T cell therapy that is not in a constituency active T cells. It's not a car T. Is a T cell that binds to her too without being active and causing all that sort of kind of release storm. And this is now active. Enrolling we actually does the patient earlier today which is very exciting. Um And so far so good. It's working according to plan I would say for an early phase trial we're seeing um no one expected off target effects but it's early days were only in the second cohort of three patients. Next slide. One of the other exciting things that we're working on hearing. Leading the work with the sponsor called innovative southern therapeutics is a true car T. Not just a T cell that can bind to the target but a T. Cell that binds and is inherently active. one of the challenges of colorectal cancer is getting the T cells into the cancer and getting enough cells into someone. You can't just give an infinite number of T cells. It'll either gum up the works or it will cause too much inflammation. And so this is an idea where we give a card T. That actually binds to two different targets. One of them is a target that allows normal expansion of the T cells and then the second targets in anticancer target. Next slide. So the target that we're looking at here is called guano cyclists. See this is a well known marker that's been established over many many years. It's present in normal colon. The the inner lining of your colon has lots of wanna cyclist C. And the basement level of the colon which points towards the blood supply. Doesn't have guano cyclist. See this makes it an appealing marker to go after it because hopefully the T cells flowing through the blood won't encounter the normal wanna cyclists in your colon and turning inflammation like diarrhea Cancer cells have a ton of this stuff, not all of them between 40 and 80% depending where you look. They have a lot of guano cyclists sea that is very heavily exposed to the blood supply into the immune response. And so the idea is that this is a marker that in normal tissue is hidden normally sequestered from the immune response but in cancer is very evident to the immune system. And so if we can generate a T. Cell that combined to this and activated T. Cell and consume it as a therapy. That's a good thing part of the challenge is getting these T cells into the second marker on this expands those T cells, they rapidly proliferate inside of the body and then do a second expansion as they encounter the cancer and this is meant to generate an immune response. This is also very very much in early days we hope to have patients enrolled. Hopefully within 2000 with the second half of 2022. Um and we're moving ahead very quickly on this from a lot of exciting work. Um I think it's a sidebar a lot of the work that we're doing is not just can we generate immune response, but what are other things about patients which are important? So, for example, are there different cells in the micro environment that can help us predict who's a responder, who's a non responders? We don't subject someone to a treatment that may be toxic. Are there things about the patient that are different? For example, the microbiome? It turns out that in other cancers the microbes in the body may predict immune response. And so we're looking at that in this and other clinical trials. And so there's a lot of side markers that are more than just the target to try and find ways to predict who's benefiting and who is not next time. So just to kind of sum up what we've talked about cancer evades the immune system by generating a suppressive environment. That's fundamentally what checkpoint in division is about, but it also evades the immune system through counterfeiting cancer is very, very similar to normal cells. So sometimes the immune system may not be suppressed. It just simply can't identify it. Checkpoint inhibitors are non targeted. So they generate an immune response in some cases. And we know this is true because when we give you checkpoint inhibitors, you can have off target effects. We also live with our main response all the time, mismatch repair, deficient colon cancers are so different, so unique that the combination of the checkpoint inhibitor and the degree of difference can overcome those challenges. But more typical colorectal cancer's probably require something a little bit more targeted than checkpoint inhibitors at least in most cases. And we're hoping that some sort of T cell directed therapy against the common market like her to or maybe one of these novel markets like GCC that we're working on will be in the area that we can treat effectively um with Diesel directed therapy. That's it. Thank you both so much. That was absolutely fascinating and I thank you both adequately communicated how complex the immune system is and how challenging it will be to try to harness it against colorectal cancer, but also highlighting some of the exciting things that we are doing to try to better understand the immune system and come up with new treatments. So thank you. That was extremely helpful. So, we did get some questions through the chat as well as through some of your registrations. So we have some time to go through those. Now I will start with dr no ac. So one question that came in was how many clinicians outside of dana Farber and Brigham and women's hospital are currently ordering immuno profile. That's a great question. So I would say that this essay was built and designed by the Brigham and Dana Farber. And so it's really just available within our community for now. I think we're leaders in this area but the underlying technology that we used to build it I think is becoming more broadly available. And so I think it although it's not going to happen in the next couple of months, I think it is something that could potentially be deployed to many other institutions over the course of the next several years. Although for now it's something that's just specific to Dana Farber patients. I will add that for any patients who are seen here by any of the oncologists. We can very easily order immuno profile using your your specimens if you agree to the to the research project. And so we are doing that for a lot of our patients. And not only will it help contribute to perhaps identifying new treatments for you, but it can also contribute to the research that we're doing to try to better understand the immune system in this disease, Jonathan. A quick follow up question. Are there similar immune, you know, similar immuno profiling essays out there that are commercially available for those who cannot or are not patients here at Dana Farber. Yeah, that is also a great question. Um in in short there really are not many essays that that can be ordered if if you want to do this sort of test on on your own tumor material. It's um it's not like you know, molecular sequencing studies where there are lots of reference labs that you can send your specimens to. I think those will probably be coming in the short term but that sort of capacity is not sort of broadly available yet. Although as you pointed out, um certainly if if you are seen at the dana Farber in consultation we'd we'd be more than happy to do this test for you and um you know probably about a third to a half of the specimens we test to actually come from other hospitals so we can very easily do that for patients being seen here. Excellent. Thank you. The next question is for dr selector. Could you talk about the differences between tumor infiltrating lymphocyte therapies versus carty and whether one has an advantage over the other in infiltrating the tumor? Yeah, that's a fascinating question. Um so a car T. Is a T cell circulating through your blood that we engineer to go after a particular target. We know what the target is. And as we said, car TSR also engineered to be very, very active, aggressive T cells. There are also engineered T cells are not engineered to be quite as active and so maybe avoid some of the off target problems. A tumor infiltrating lymphocyte tails than anything for them are the native t cells or maybe not native. They're the resident t cells inside of the tumor. And so the question remains, are those t cells able to generate an immune response against the cancer and it's a little bit hard to figure out the chicken versus the egg with tails. Um, there's a lot of enthusiasm to giving til therapy. We actually have some trials here at Dana Farber in colon cancer, but other cancers where we're doing til therapy followed by those generic inflammatory markers were giving a drug called high dose interleukin two high dorsal to um So one of what is old is new again, direct from the seventies. That's back. Um, and so that's an area of research here at Dana Farber. Very, very active. Well, first open in lung cancer, I think colon cancer doesn't have as many details as some of the other cancers. And so it may be hard to do that as the next step, but I think it'll be very, very promising and maybe the future is actually a combination of engineering a tale to be both somehow sensitive to the cancer. That's why it's there in the first place but also setting off the target more actively or increasing its its activation. Thank you. And another question that came in, sticking with you for now. Dr selector is how can we learn from responders in immunotherapy trials and and and get that data out there. And this may be particularly challenging in microsatellites stable colorectal cancer where we don't see that many responses. Yeah, I think this is the value of clinical trial enrollment um clinical trials when well designed should have high quality cooperative work and there's a lot of the work that we do here. So it's not just responded non responsive. That's important. That's critically important. But why and I think it's actually equally important to ask why we fail is why we succeed. Um So I would say that speaks to the value of correlative science, the value of collaboration between investigators and and drug companies in the labs. Um the y is a lot harder, but we're working really, really hard to look on all sorts of levels. But why we see benefit, why we see failure and and how we can generate that. Thank you. And perhaps sticking with this this theme of clinical trials dr no, ac you're doing a lot of work using specimens and diet lifestyle information and genetic sequencing results from samples collected from patients participating in clinical trials and not necessarily immunotherapy trials, but chemotherapy trials. Can you tell us how those will or may eventually be helpful for better understanding the immune system in colon cancer? Yes, I think that that, you know, hits upon one of the things about the immune system in colon cancer. That's really challenging, which is the fact that so many things influence it, right? And the colon and really the whole gi tract is just kind of so unique in comparison to most other organs where there's such a large influence of the microbiome, there's a very broad sort of environmental exposure and in a lot of ways our understanding of the immune system and our ability to target it has maybe lagged a little bit in some of the G. I. Tumors simply because the environment is so complex. And so I think even outside of clinical trials or clinical trials that were focused specifically on immunotherapy all of those patients, every colon cancer that we have, where we understand something about the patient's history, their diet, their lifestyle can be helpful because when we can build up large enough groups of those patients were able to start parsing things out like your particular diet factors and when you develop the colon cancer or of the colon cancers, if there is a pre election to develop a certain type. And so I think it's just as much kind of amassing a critical amount of that data and knowing details about each patient that allow us to look at a broad variety of factors and hopefully some of those then downstream lead to better ways of preventing colon cancer or opportunities to better target it. Yep, that's great. And you know, I think your your data on young onset colorectal tumors and how they may have fewer immune cells very close to the tumor cells compared to older onset tumors is fascinating. Do you have hypotheses about why that might be because it certainly could perhaps perhaps explain why there may be more young onset colorectal cancer. Why it may be harder to treat. Yeah, that's a it's a fascinating result and in some ways it's a little opposite from what we would have expected. You know, very naively, you tend to think of younger people as having a more robust or strong immune response and you might expect them to either have more immune cells in their tumor or immune cells that really want to be closer to the tumor cells themselves. And and so why younger patients should have immune cells being pushed away from the tumor cells a little bit more? I honestly don't know. Um there are definitely experiments that we can do to try to figure out is it a primary problem with the tumor cells? Is that a primary problem with the immune cells? Maybe it's both, Maybe it's something else. Um but we're really just at the point of starting to think about what those experiments should be to figure out why we saw that association. That's great. And, you know, on the topic of whether or not we can predict who will respond to immunotherapy or not. Dr selector. I was wondering if you could comment on what we know about whether metastases in different organs actually affect response to checkpoint inhibitors? Yeah, this is actually a really important area where we even have a trial opening hopefully in days to weeks. Looking at just this, it is very clear that cancer metastases in different parts of the body behave differently, not just in terms of chemotherapy, which has been known for a while, but in particular the immune response, even in the most immune responsive cancers, large volume in texas is bigger than the liver tend not to respond to me in therapy. And in colon cancer, it looks like a trial drugs coming forward, never works in the liver, almost never works in the liver. So that we are going to focus at least for this clinical trial. That's opening on non hepatic, non liver mass tax disease. Why that is, I don't think it's entirely clear it could actually be it's not delivered. That's the issue of the other places. So for example, maybe the lung is more pro inflammatory environment and so the presence of disease in the lung is more the issue. Or it could actually be that the deliver such a suppressive environment and that remains to be seen. That's going to be an important area of research. But it's definitely true that where cancer metastasizes to makes a difference. And we actually have a trial focused on that and dr Novak do you do we know what the differences are in the immune micro environment in the liver, in the lung that may be contributing. Why we are seeing these different responses in patients based on where they have metastases. Yeah, that's that's a great question. I think we're just at the at the point of really being able to map that out. We also know that for different tumor types that end up in the liver or the long their immune profiles will look different than colon cancer for example. So there's something that's partially different by the tumor and there's also something that's partially different by the organ that the tumor has ended up in. It's pretty easy for us to measure differences in immune cell composition and figure out if there are more fewer T cells or macrophages or neutrophils or whatever your favorite immune cell type is. Um but it's significantly harder to figure out why there happened to be fewer or more there. Um, but again, there are definitely experiments that that we are doing and along with others to help figure out what are those mechanisms that are regulating, you know, um, the failure of the immune response for tumors that had metastasized to deliver. Why does that tend to work out better for us to end up in the lung, for example, thank you. And you know, just to address the question that came in in the chat, you're doing such exciting work characterizing the immune environment of a lot of tumors. Somebody asked whether the tumor is gathered in the Count me in project. Can potentially be used in our research and just to quickly let everybody know what the Count me in project is. It's a digital media platform that allows patients to participate in research on colorectal cancer no matter where in the US or Canada you are and everything is done remotely online. So the website is joined Count me in dot org. And you know through that will be able to collect if you consent medical information, treatment information, diet, lifestyle information as well as blood tumor and stool specimens so that we can really analyze a large number of tumors to really better understand the immune system's role in colorectal cancer. So I do urge all patients with colorectal cancer, no matter what age you are to consider participating in that study. Um and then a couple more questions um for a doctor selector what stages of colorectal cancer? Our immunotherapy used in right now. Mm hmm. So first talking about check, sorry, mismatch repair deficient cancer. So lynch Benjamin and the sporadic mismatch repair deficient cancers. Um there are trials looking at all stages for that. So there's immunotherapy trials that are completed in advanced disease. There's a very important cooperative the clinical trial of conventional adjuvant chemotherapy with fall Fox plus or minus. A checkpoint inhibitor called the T cell is a map. And so that trial will be done. Hopefully shortly we're close. Um and that should answer the question which is better chemo or chemo plus immuno or maybe even in you alone in earlier stage disease for um for the mismatch repair proficient for the microsatellites stable camps is the average gold record cancer. We're not there yet On early stage disease with checkpoint inhibitors, there have been some early reports of preoperative immune therapy maybe making some sort of changes. But it's not totally clear to me if it changes what we see in the tumor over changes the outcome. And so um the presence of something in a tumor that we can manipulate. It doesn't mean that we manipulated successfully. And so it remains to be seen. Again. This is the chicken and egg problem with the immune system. If a cell is present that it may or may not be valuable information, it may not be therapeutic information. So for at least days disease, I think where we are always out, there have been a number of sort of unfortunate failures for lack of better term in particularly rectal cancer. With the additional immune therapy. To conventional therapy has not been successful. But I think that we are entering an era where with careful targets, we should see some real successes. Advanced disease. Thank you. And I think that does address a couple of questions about whether you think we're advancing the needle for immunotherapy treatment in MSs colorectal cancer. I do agree with you. There's a lot of exciting work going on. I I do think we'll hopefully see some advances soon. The more we do the research and better understand the role of each immune cell type in this disease. And one other question is what clinical trials do we have now that our immunotherapy available or coming soon at dana Farber if you don't mind, doctor selector just summarizing that really quickly. What's on the horizon and what's available now? I think that that would be a good way to end this women. Are you always have to talk about trials. Um so as I said, we have the open and rolling tactic to study. This is for the very particular 5 to 6% of patients with her two amplified colon cancer. And so that is an engineered T cell that doesn't have quite the toxicity of car T. Um and as as you all know here on in the group were working to launch this by specific car T for more common market Gcc which may be available to up to 80% of patients with advanced colon cancer. So that's a very very important targeted treatment in terms of the more non target treatment, the checkpoint inhibitors. We have a checkpoint inhibitor opening any day now. Also from a producer here in boston called a genius. Um that is A C T. L A for antibodies or not a pd one antibody for non hepatic metastatic disease. And I think those those are the big three right now there are always more coming, we've had several completed clinical trials waiting for information on them using um veg F inhibitors inhibitors, things like that in colorectal cancer and we'll see what else comes along. But I do think that the targeted treatments probably have the most legs. Um Zach checkpoint inhibitors will be important tools to help us, but I don't know if they can overcome that counterfeit problem with colon cancer. Thank you a lot of exciting studies coming soon. And simultaneously with doing these trials, we will also be studying the microbiome and analyzing tumors to again better understand the role of those factors in response to these very exciting new immunotherapy drugs. So, thank you both Again, I hope this has been helpful for all the participants to let everybody know. This session has been recorded and will be available on our website in case you want to view it later or share with other people who may find it helpful. And please don't forget to register for some of our other virtual events which are going on throughout the rest of the month of March, which is colorectal cancer awareness month. Thank you so much for attending. Good night.
