May 27, 2022
Dr. Diwakar Davar and Dr. Jason Luke, both of the University of Pittsburgh’s Hillman Cancer Center, share the latest news on immunotherapy trials KEYNOTE-A10, LIBRETTO-001, and other key IO studies across tumor types featured at the 2022 ASCO Annual Meeting.
Transcript
Dr. Diwakar Davar: Hello, and welcome to the ASCO Daily News Podcast. I am Dr. Diwakar Davar, and I'm an assistant professor of Medical Oncology in phase 1 therapeutics, at the University of Pittsburgh's Hillman Cancer Center, and the guest host of today's podcast. I'm delighted to welcome Dr. Jason Luke to this podcast. He's the director of the Cancer Immunotherapeutic Center at the Hillman Cancer Center, University of Pittsburgh, and a great colleague and friend.
Today we'll be discussing some key posters that highlight some advances in immunotherapy that will be featured and the 2022 ASCO Annual Meeting. You will find our collective disclosures in the show notes and the disclosures of all guests on the podcast are available on our transcripts at asco.org/podcasts.
So, Jason, thank you for coming on the podcast today.
Dr. Jason Luke: Well, thanks very much for the invitation. I always love doing these podcasts for ASCO, and never love anything more than hanging out with my friend Diwakar Davar.
Dr. Diwakar Davar: Well, thank you! Below are the abstracts we've selected. We will start with Abstract 2504. This is a phase 1 trial of the TIM-3 inhibitor cobolimab monotherapy, singly and in combination with the PD-1 inhibitors nivolumab or dostarlimab. Phase 1 data from the AMBER trial with the presenting author being Dr. Gerald Falchook. And this is a trial that initially started several years ago. And I know Jason, that you were involved with the inception of this agent, that TIM-3 inhibitor. So, walk us through, TIM-3. It's a third-generation checkpoint, we now have TIGIT LAG coming into the landscape. Definitely a first indication for LAG-3 melanoma with a positive trial, RELATIVITY 047. So, where are we with TIM-3? Why should we be excited about TIM in general, and this data in particular?
Dr. Jason Luke: It is quite exciting, especially building off the recent data that we saw for relatlimab or LAG-3 because it's becoming clearer that a number of these other immune checkpoints that we have been talking about for many years, actually really can be effective when used in the right setting.
So, this drug, this anti-TIM-3 antibody cobolimab monotherapy, as you mentioned, started out in a phase 1 clinical trial dating all the way back to I think about 2015. And that was at the time in immuno-oncology when everybody was so excited, [and] they thought everything was going to work immediately.
Subsequent to that, obviously, we've had some hurdles that we've had to come over. But we're coming back to some of these agents now, which are looking very exciting. So, just in the same way we think about blocking PD-1 or now blocking LAG-3 to reinvigorate T cells in the tumor microenvironment, there's a good chance and a high probability based on preclinical data that blocking TIM-3 could be just as effective as blocking LAG-3, so to say.
Now, one thing that I note in this abstract is really the safety finding and early PK analysis. And so, this is the important work we do early on to understand the drug. It's important to be aware that in a study like this, it's very hard to seek efficacy signals.
So, when you see this poster, really, you probably shouldn't be thinking, ‘Oh, this is a frontline phase 3 trial,’ but rather that the efficacy is going to be a secondary consideration. Rather, what's quite important is looking at the properties of the drug and looking at the safety signals around that. And what we can see here is that TIM-3 appears to be quite safe when blocking it in conjunction with anti-PD-1 across several different tumor types. And that really sets the stage then to think about moving this into earlier lines of therapy across many different cancers.
And so, here we see advanced solid tumors but focused on lung cancer and melanoma and kind of the usual tumors we think about, and people can keep their eyes open because there are other posters of this molecule with PD-1 in some of the other sections outside of developmental therapeutics.
Now, one thing I would like to get your opinion on because your group has focused a lot on TIM-3, as I described it as this T cell centric mechanism to reinvigorate exhausted T cells. But it's possible that TIM-3 does other things as well. And I don't know if you want to comment on that or give any other feedback that you've had when thinking about this AMBER Trial.
Dr. Diwakar Davar: That was an excellent summary, Jason, of really what is a truncated 8-year track record of developing this agent all the way from 2015. But you bring up a very interesting point, which is: exactly what does this drug does in the non-T-cell compartment?
Some very interesting data from Brian Ruffell in a paper that was published about 3 years ago now suggested that TIM-3 was actually potentially a myeloid checkpoint, meaning that, in a tumor model in which Dr. Ruffell was studying this in the context of breast cancer, the drug primarily appeared to work on the effect of antigen-presenting cells and augment the presentation of antigen to T cells suggesting that it may be, in addition to being a chronicle T cell exhaustion marker, it may also be reinvigorating antigen-presenting cells. And the question of whether or not the role of TIM-3 on APCs as well as the role of TIM-3 on T cells, and which of these compartments are more important, and how these compartments segregate in any given cancer across many different lines of therapy will hopefully be something that we disengage, and understand a little bit better as we look at biomarkers of this drug across different settings.
And especially to that point, Jason, the biomarker question, you'll notice that very interestingly, that was a signal in which that drug had a certain response rate. Again, as you correctly point out, we cannot read too much into response rates in very small patient numbers. But very interestingly, there was a slightly higher response rate at the 300 milligrams, which is not the top dose level of the drug, and a slightly lower response rate at the ceiling dose of the drug that was tested, 900 milligrams, leading the investigators to conclude that the RP2D, was actually 300 milligrams every 3 weeks and not 900 milligrams.
What are your thoughts on dose in the context of immunotherapy (IO) drug development? And why might it be that 300 is the optimal dose as opposed to 900?
Dr. Jason Luke: That's a complicated question. I mean, when we think about checkpoint blockade, we classically think about it as only blocking on T cells. But to your point, if there are multiple mechanisms in play, sort of modulating other cell compartments actually may start to do different things at different doses that maybe weren't our primary intent as we went into the trial.
That's a little bit of hand waving, immunologic hand waving, but I think the data are the data and once we hit an effective dose level, there's really no need to really push the dose that much further. But that really emphasizes the importance of these kinds of early phase clinical trials.
So, I'm really looking forward to seeing this data. For disclosure, obviously, we have both been investigators on this trial. But we're very excited about the idea that there may be hope for a fourth checkpoint to come forward in the field beyond just PD-1 CTLA-4, and LAG-3, maybe now here with TIM-3.
Dr. Diwakar Davar: So, with that we’ll go to the next abstract and that is Abstract 2516, “Phase I trial of adjuvant autogene cevumeran, an individualized mRNA neoantigen vaccine, for pancreatic ductal adenocarcinoma.”
So, this is an mRNA vaccine from our good friend, BioNTech. And that's been essentially evaluated in the context of highly lethal cancer, pancreatic ductal cancer, and specifically in the context of adjuvant vaccines, specifically in the setting of patients who had followed definitive pancreatic cancer surgery.
So, Jason, you know a lot of neoantigen vaccines, you've led some of these trials, really, the neoantigen vaccine is really the primary reason we are actually having an in-person meeting this year, because if not for this company and others like this, really this pandemic would not be behind us.
What are your thoughts on the role of neoantigen vaccines in cancer therapeutics, and also, particularly this particular trial in the data, the immunological data, and the clinical data regarding the development of neoantigen-specific T cells in this setting, and what this means for you?
Dr. Jason Luke: Right. So, the idea of targeting neoantigens as cancer immunotherapy was really all the rage a few years back, and it was thought based on preclinical animal models that this was just going to be the secret sauce, and this would be the new targeted therapy for immunotherapy. And it isn't to say that that's not true, but the first generation of neoantigen, peptide-based vaccines for the most part, unfortunately, just kind of didn't end up moving the needle the way we had hoped.
The question then was raised: is that because targeting neoantigens isn't reasonable, or is that because the setting where we were trying to do it in the refractory disease area was not the optimal way to leverage this?
And so, a couple of different companies and trials now are coming forward looking at targeting neoantigen in a minimal residual disease setting where the idea could be that immunologic responses that you could generate wouldn't be hampered by all the immunosuppression associated with the tumor microenvironment.
And so, here we have this molecule, which you eloquently pronounced, ‘autogene cevumeran.’ It’s an RNA-lipoplex neoantigen vaccine. So, it's not a peptide. It's more like the COVID-19 vaccines actually. And it's being given after surgery, followed by anti-PD-L1 followed by chemotherapy.
So, it's a complicated regimen, but it's very intriguing these early data, which do show that the patients who got the vaccine seemed to have better and longer-term outcomes. But then as you emphasize, really, I think probably what's at the heart of this that really makes it exciting is their ability to immune monitor the patients, meaning to look for antigen-specific immune cells from the peripheral blood in these patients to be able to identify those immune responses as being specific to cancer. Because this kind of a clinical trial, it's still signal seeking and proof of concept kind of trial.
In order to actually establish that a vaccine approach in a post-surgical setting would have efficacy, we need to do a large randomized trial. And so, this is not that yet. But I think these data really point in the direction that that could be a reasonable thing to try. And when you think about pancreatic cancer, where we've made no success with immunotherapy, really in a meaningful way in terms of checkpoint blockade, at least, that's pretty exciting actually to think about.
I would actually marry this dataset with another that we actually saw at the American Association for Cancer Research (AACR) meeting that also looked at neoantigen targeting and antigen-specific responses in colorectal cancer, again, and in a similar setting with the minimal residual disease setting.
And so, I think this highlights that we may need to start thinking about using immunotherapy in different ways than we had before. Obviously, everybody knows about using PD-1 blockade in lots of different cancer types that are really for metastatic disease, or maybe even for adjuvant now in melanoma a little bit. But maybe there's this space, which is the minimal residual disease setting where you might be able to detect by ctDNA after surgery, the patients are still positive. And maybe you could treat that before there's visible cancer, and maybe certain immunotherapies could be more valuable in that setting than others. And that's where I think maybe some of these mRNA technologies really might find their sweet spot.
So, coming back to this abstract, I think really, the emphasis point here is the novelty of generating patient-specific neoantigen vaccines, and then being able to track linearly over time the immune response against those vaccines.
I think with that kind of technology and being able to leverage that, I think we're really headed towards a real shift in the way we think about managing cancer in a post-surgical setting, again, thinking about MRD, or minimal residual disease, maybe in a way that our leukemia colleagues have been thinking it about for a long time.
Dr. Diwakar Davar: That's an excellent summary of a very, very complicated, both setting, and in this case, a therapeutic landscape. So, well said, well summarized, and we'll now pivot to Abstract 2514. So, this is ‘Efficacy and safety of NT-I7, long-acting interleukin-7, plus pembrolizumab in patients with advanced solid tumors: Results from the phase 2a study’ [and] the presenting author is Dr. Aung Naing from [The University of Texas] MD Anderson [Cancer Center].
So, Jason, you know, with checkpoints, we've got so many thoughts about checkpoints, particularly given the rather unfortunate failure of BEMPEG in the context of melanoma.
So, we've got lots of interesting cytokines that we think of as important in the context of immuno-oncology 2, certainly 12, 15. You've been very involved with IO-15. We've got a lot of clinical trials studying IL-12. And now we've got one studying IL-7. So, tell us what do you think of this IL-7 targeting approach in the context of cytokine-based therapeutics?
Dr. Jason Luke: I think it's really important to emphasize on first principles, for those that are listening, who don't think about immunology all the time that not all cytokines are the same thing.
So, interleukin 2 that many people have heard of is very different actually than interferon. And that's very different from many of the other cytokines, the ILs, and everything, right?
So, IL-7 is a very potent cytokine that's associated with the expansion of immune responses, and that can drive interferon gamma-dependent effects. And you should hear whenever I say interferon-gamma is sort of a link through to PD-1 responsiveness. Because we think the mechanism that underpins anti-PD-1 effectiveness in patients really is interferon gamma biology.
So, IL-7 has been a molecule, it's been of a lot of interest but really was too toxic to try to deliver. But now we have novel drug delivery sorts of approaches that are being developed to try to bring the drug in, in a way that doesn't cause such systemic toxicity.
So, in this clinical trial, this NT-I7 molecule is given intramuscularly, every 6 weeks in conjunction with pembrolizumab, and very interestingly, in a small number of patients, but there were resist responses observed across a series of tumors that you really wouldn't expect should be responsive in any way to pembrolizumab alone. And so, we're talking about microsatellite stable colorectal cancer, pancreatic cancer, and some others as well.
And in conjunction with that, they were able to identify some of the biomarker effects we would think we would see with IL-7, such as expansion of peripheral immune compartments. And the toxicity profile was really consistent with what we've seen with fevers and chills, but manageable in a way that previous approaches really weren't.
So, I think this is really exciting because I think the idea here then is with this IL-7 approach, we might expand the kinds of cancers that we could go after, in conjunction with anti-PD-1 again, pancreas, colorectal cancer. I think that's really where the unmet need lies in oncology.
So, I really applaud these kinds of approaches and several of these cytokine approaches, and what we're going to talk about them, I think, have the potential to do that over the next couple of years.
Dr. Diwakar Davar: Excellent! Pivoting now to a different cytokine, but one that was alluded to before IL-12. So, Abstract 2518 is ‘Phase II evaluation of the combination of PDS0101, M9241, and bintrafusp alfa in patients with HPV 16+ malignancies,’ and the presenting author here is Dr. Julius Strauss of the NCI Cancer Center and the Clinical Center of the National Cancer Institute at the National Institutes of Health.
So, what do you think, Jason, about the role of the HPV targeting vaccine, in this case, that was added to IL-12 immune-cytokine and bintrafusp alpha contextualizing the recent data that we have of bintra along with what is a very interesting result here?
Dr. Jason Luke: Yes, I think building on the last abstract where we talked about IL-7 as some novel biology now we move to IL-12, which again introduces other biology. So, interleukin-12 is a complicated cytokine, but one that's strongly associated with initial immune responses or immune priming, as well as enhancement of anti-tumor effects in the tumor microenvironment.
So, here we have sort of a 3-legged approach. So, the vaccination approach against HPV really can generate a strong immune response initially, and that can be supported with the IL-12. And then you come in with anti-PD-L1 and to whatever extent the TGF data is relevant here. And so, you have this cocktail where you're generating tumor-specific responses with a vaccine, you're supporting them with IL-12, and then blocking PD-L1.
And as we go back even a couple of abstracts we talked about, now we sort of have a cocktail right of approaches. And so, I think this is very exciting. It's unique in that, in these tumors, obviously, HPV is the driving force of cancer. So, developing a vaccine against that is fairly straightforward. But I really like this concept of bringing forward sort of a multi-dimensional immunotherapy approach. And we'll note they have previously presented data on this trial, I think last year at ASCO, actually. But what they see are pretty strong response rates, almost 30% range in PD-1 refractory tumors.
Again, that's our area of really high unmet need. It's hard to read through how useful a PD-1 naive treated patient here, although the response rates were high. But to me, it's really those patients who had progressed on PD-1 where they're getting these responses that tells me that this really could be something that's useful and potentially could be expanded beyond just say head neck cancer to any HPV relevant malignancy.
Dr. Diwakar Davar: Excellent! Now on to our last abstract. Abstract 2520, ‘Effect of intratumoral INT230-6 on tumor necrosis and promotion of a systemic immune response: Results from a multicenter phase 1/2 study of solid tumors with and without pembrolizumab (PEM) [Intensity IT-01; Merck KEYNOTE-A10].’ The first author is Dr. Jacob Thomas.
Jason, we've seen a lot of interesting intratumoral therapies. You and I have both done a lot of studies in looking at intratumoral agents from toll-like receptor agonists, TLR-9, TLR 7-8, and more recently, oncolytic viruses.
So, contextualizing IT230-6 in the spectrum of intratumoral therapies, how do you feel about this drug, which is actually a very interesting novel drug. It's not just a TLR agonist, or for that matter, an OV, very interestingly, it's an intratumoral therapy that has actually got chemotherapy in it. So, how do you feel about this drug? How do you feel about the responses that we've seen? And particularly how do you feel about the setting in neoadjuvant breast cancer?
Dr. Jason Luke: Yeah. I would pick up where you said that this drug INT230-6 is just a really interesting concoction. So, it's cisplatin mixed with vinblastine, in a specific amphiphilic molecule that allows it to diffuse in through the cancer.
And so, if you had said that to me a few years ago, I would have looked at you and been like, ‘What are you talking about?’ But I think the data that's been emerging for this is just really interesting because something about this chemotherapy cocktail actually drives immune responses. And really what the focus of this abstract is on is showing that you get an influx of CD foreign CDTa cells into the tumor microenvironment that's associated with a therapeutic benefit.
I think that's just really, really interesting to think about. It sort of makes one wonder when we're doing these intratumoral injections, how much of it is just the injection, and how much of it is the therapeutic agent, but I think it's a really novel therapy, and one that appears to be very well tolerated as well. And that's also the exciting part. When you hear cisplatin and vinblastine, you think, ‘Oh, well, that's not going to work.’
But apparently, it stays right in the tumor and generates these immune effects. I think it's very exciting. I think their approach here—going after what we usually call cold tumors, ones that don't respond to immunotherapy, you mentioned breast cancer—I think it's really interesting. I'm really looking forward to seeing the actual data from this abstract because, on first pass, it wouldn't have been what I thought about in terms of driving immune responses, but maybe it just goes to show that there's a lot more to understand there about immunogenic cell death and some of these other concepts that we bandy about. But I think this will be one of the most interesting abstracts actually to see the data for once it's available.
Dr. Diwakar Davar: Great! Taking a slight pivot from that. You've been involved in the development of novel response endpoints. One of the issues that we have with intratumoral therapies is that you're measuring a lesion that you inject, so now you inject something and it gets a little bigger. Is it getting bigger because it's growing? Is it getting bigger because the drug is working? We don't know. We have now itRECIST, which you have been working on.
What's very interesting is that whether you look at itRECIST, or RECIST, irRECIST, or imRECIST, when you have the monopoly of different response endpoints we have to deal with these days, these patients have monotherapy responses in non-injected tumors. How do you feel about that as a drug developer and somebody who's giving patients drugs like that? What is your impression of having shrinkage in the non-injected tumor?
Dr. Jason Luke: I think it's really exciting about this concept of the abscopal effect that we've bandied about for years. Despite being an investigator in this space, I'm really excited to actually see the data and to understand what these out of field responses are. If it's really true that this is robust, I mean, it could potentially be like a game-changer kind of thing. But I'll reserve judgment until I see the actual scans of the tumors that actually shrank that weren't injected.
Dr. Diwakar Davar: Fantastic insights, Jason. So, thank you for taking the time to join us on this podcast and to highlight these extraordinarily important advances in immunotherapy.
Dr. Jason Luke: I appreciate the opportunity to participate today.
Dr. Diwakar Davar: So, thank you, and thank you to our listeners for your time today, you will find the links to the abstracts that we discussed today in the transcript of the episode.
Finally, if you're enjoying the content on the ASCO Daily News podcast, please take a moment to rate review and subscribe wherever you get your podcasts.
So, thank you, Jason. And thank you to the team for putting this together.
Disclosures:
Dr. Diwakar Davar:
Honoraria: Merck, Tesaro, Array BioPharma, Immunocore, Instil Bio, Vedanta Biosciences
Consulting or Advisory Role: Instil Bio, Shionogi (Immediate Family Member), Vedanta Biosciences
Research Funding: Merck, Checkmate Pharmaceuticals, CellSight Technologies, Zucero Therapeutics (Inst), GSK, Merck, Arcus Biosciences
Patents, Royalties, Other Intellectual Property: Application No.: 63/124,231, and Enteric Microbiotype Signatures of Immune-related Adverse Events and Response in Relation to Anti-PD-1 Immunotherapy
Dr. Jason Luke:
Stock and Other Ownership Interests: Actym Therapeutics, Mavu Pharmaceutical, Pyxis, Alphamab Oncology, Tempest Therapeutics, Kanaph Therapeutics, Onc.AI, Arch Oncology, Stipe, NeoTX
Consulting or Advisory Role: Bristol-Myers Squibb, Merck, EMD Serono, Novartis, 7 Hills Pharma, Janssen, Reflexion Medical, Tempest Therapeutics, Alphamab Oncology, Spring Bank, Abbvie, Astellas Pharma, Bayer, Incyte, Mersana, Partner Therapeutics, Synlogic, Eisai, Werewolf, Ribon Therapeutics, Checkmate Pharmaceuticals, CStone Pharmaceuticals, Nektar, Regeneron, Rubius, Tesaro, Xilio, Xencor, Alnylam, Crown Bioscience, Flame Biosciences, Genentech, Kadmon, KSQ Therapeutics, Immunocore, Inzen, Pfizer, Silicon Therapeutics, TRex Bio, Bright Peak, Onc.AI, Stipe, Codiak Biosciences, Day One Therapeutics, Endeavor, Gilead Sciences , Hotspot Therapeutics, SERVIER , STINGthera, Synthekine
Research Funding (Inst): Merck, Bristol-Myers Squibb, Incyte, Corvus Pharmaceuticals, Abbvie, Macrogenics, Xencor, Array BioPharma, Agios, Astellas Pharma, EMD Serono, Immatics, Kadmon, Moderna Therapeutics, Nektar, Spring bank, Trishula, KAHR Medical, Fstar, Genmab, Ikena Oncology, Numab, Replimmune, Rubius Therapeutics, Synlogic, Takeda, Tizona Therapeutics, Inc., BioNTech AG, Scholar Rock, Next Cure
Patents, Royalties, Other Intellectual Property: Serial #15/612,657 (Cancer Immunotherapy), and Serial #PCT/US18/36052 (Microbiome Biomarkers for Anti-PD-1/PD-L1 Responsiveness: Diagnostic, Prognostic and Therapeutic Uses Thereof)
Travel, Accommodations, Expenses: Bristol-Myers Squibb, Array BioPharma, EMD Serono, Janssen, Merck, Novartis, Reflexion Medical, Mersana, Pyxis, Xilio
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