ADCs in Breast Cancer: Sequencing, Resistance, and Managing Toxicity

Drs. Hope Rugo and Sara Tolaney discuss the promise of antibody-drug conjugates (ADCs) in the treatment of breast cancer, highlighting key trials that shed light on matching the right ADC to the right patient in the right setting. They also explore how combinations and sequencing of ADCs can augment their efficacy, the mechanisms of resistance, and the future potential of biomarkers to predict patient response. TRANSCRIPT Dr. Hope Rugo: Hello, I'm Dr. Hope Rugo, your guest host of the ASCO Daily News Podcast today. I'm a professor of medicine and director of breast oncology and clinical trials education at the University of California, San Francisco's Comprehensive Cancer Center. Antibody-drug conjugates, or ADCs, are rapidly changing the treatment landscape for patients with breast cancer. ADCs consist of antibodies that target tumor-specific antigens on the cell surface, chemical linkers, and cytotoxic payloads that can act powerfully to kill cancer cells. On today's episode, we'll be discussing advances in research to match the right ADC to the right patients and in the right setting. We'll also talk about the next steps, assessing how combinations and sequencing of ADCs can augment their efficacy, improve options for patients, and identify biomarkers in the future to predict how patients will respond so that we can match the right treatment to the right patient and their tumor. We need to gain a better understanding of the mechanisms of resistance that occur upfront as well as under the pressure of treatment.  Joining me for this important discussion is Dr. Sara Tolaney. Dr. Tolaney is an associate professor of medicine at Harvard Medical School, associate director of the Susan Smith Center for Women's Cancer, and chief of the Division of Breast Oncology at the Dana-Farber Cancer Institute in Boston.  You'll find our full disclosures in the transcript of this episode and disclosures of all guests on the podcast are available at asco.org/DNpod. Dr. Tolaney, we're delighted to have you on the podcast today. Thanks for being here. Dr. Sara Tolaney: Thank you so much for having me. I'm looking forward to the discussion. Dr. Hope Rugo: Great! So, we'll move forward, and because we're friends and colleagues, I'm going to refer to you as Sara, and I'm Hope, since we’ll dispense with formalities in our discussion.  A lot of the talks that we give about ADCs start out with “a revolution in breast cancer therapy.” And indeed, this is a really exciting time with ADCs as treatment for breast cancer, and we're rapidly moving these agents into earlier disease settings. Can you tell us a little bit about the possibilities and challenges of using ADCs for the treatment of breast cancer today? Dr. Sara Tolaney: It's interesting that you say antibody-drug conjugates as revolutionizing outcomes of breast cancer, which I think is true. But on the flip side, I think it's also bringing up a lot of questions about how to use them, when to use them, and how to manage side effects. So there are a lot of good strengths for these antibody-drug conjugates, but a lot of unknowns that we're still trying to figure out. We had an older antibody-drug conjugate T-DM1 that we were all very familiar with that for years had been a treatment that we used very commonly in metastatic disease and now even use in early breast cancer, and I think has changed outcomes for patients. But over time, we've been able to develop newer antibody-drug conjugates as the technology has really evolved so that these agents now are able to deliver a lot of chemotherapy into a cancer cell. We're seeing very high drug-to-antibody ratios, and we're also seeing that these drugs can function via bystander effect, whereas T-DM1, for example, was not able to do that. But our newer ADCs, like sacituzumab govitecan or trastuzumab deruxtecan, are agents that do allow chemotherapy to get into that cancer cell, but also to get into neighboring cells.  And I think the technology evolution in being able to build these so-called next-generation ADCs has allowed for really unprecedented efficacy that we've not seen before. And it's also allowed us to develop these drugs in a way that's been different. Originally, we were developing T-DM1 to turn off HER2 signaling and to deliver chemotherapy into a HER2 cell. At least that's what we thought originally. And now we're really evolving so that we can just find a tiny bit of protein on a cancer cell and use it as a target, really in a subtype-agnostic way. And I think it's just a different way of thinking about how to use these agents to really deliver a lot of chemotherapy into cancer cells and have very robust efficacy. Dr. Hope Rugo: Yes, it is fascinating that some of the suppositions that we made with the first ADC don't seem to really hold true as well. And maybe they hold true in varying levels for the different ADCs. For example, this bystander effect is thought to allow us to target cells that have very low expression of the receptor that can be internalized even lower than our ability to detect these receptors by immunohistochemistry. And maybe we'll talk about that in a little bit.   But first, you mentioned already sacituzumab and trastuzumab deruxtecan, the ADCs that are currently approved for breast cancer. But can you tell us a little more about those ADCs and the key trials that have led to approval of these targeted agents? Dr. Sara Tolaney: Yes, I think when we first saw the data that came out with T-DXd and DESTINY-Breast01, I think my jaw dropped because I had never seen a waterfall plot like that. This was a single-arm study that looked at T-DXd in patients with very heavily pretreated metastatic HER2-positive breast cancer and saw very high response rates of over 60% and a clinical benefit rate of almost 98%, meaning that almost every single patient who got the drug and had a median of six prior lines of therapy had reduction in tumor size. And that’s unreal. I think it was revolutionary in the sense that we had never seen that kind of activity in such a pretreated population. The agent was studied in other registration trials, DESTINY-Breast03, which looked at T-DXd and compared it head to head with T-DM1 in a predominantly second-line metastatic HER2-positive population, and here, again, unprecedented results. I’ve never seen a p value like that or a hazard ratio of, again unreal, of a little under 0.3 and seeing a 28-month PFS with T-DXd relative to just a little under 7 months PFS with T-DM1. We have never seen patients with metastatic HER2-positive breast cancer have a PFS that long. Even in CLEOPATRA, it’s a little under 19 months in the first-line setting, where people were predominantly naïve to HER2-directed therapies. This, again, is really changing outcomes for patients.   But then, I think, when we go to the next step, we studied T-DXd in patients with HER2-positive breast cancer and it had again these unprecedented results. But there was some early data suggesting that it could even work in tumors that weren't truly HER2-positive but what we call HER2-low, meaning that they weren’t HER2/3+, they weren’t HER2-0 but they were 1+ to 2+ and not FISH amplified. And so even with a little bit of protein there, they were seeing activity in the early phase studies and so it led to DESTINY-Breast04, which compared T-DXd to chemotherapy of physician's choice in people who had had one or two prior lines of chemotherapy in the metastatic setting. It was predominantly geared to look at outcomes in hormone receptor-positive breast cancer. But there was a small group of 58 patients with triple-negative disease that were also included in that trial. And here again, a very unprecedented outcome seeing a response rate of about 50%, which, again, we never see in pretreated hormone receptor-positive disease. And a PFS of 10 months, and again, these are people who already had one or two prior lines of chemotherapy. So it’s, again, really changing outcomes. And so now I think it leads us to a lot of other questions that we are addressing in trials - can this drug work even if the tumor has maybe no HER2 expression, what about HER2-0, what about HER2-ultra low, meaning a little bit of staining but not quite 1+. And so these are questions that I think we will need to address and there are studies that will help us address that. On the flip side, we saw sacituzumab govitecan get developed in breast cancer. Initially, we saw very impressive results from a single arm study of sacituzumab in metastatic triple-negative disease where we saw response rates of a little over 30%. These are patients who were very heavily pretreated with metastatic triple negative breast cancer where, unfortunately, response rates end up being in a 5% range so it was a home run in that setting. So that led to the ASCENT trial, which compared sacituzumab govitecan to treatment of physician's choice therapy and that study really enrolled people who were, in essence, second line and beyond in the metastatic triple-negative setting and showed almost triple progression free survival, in essence, doubled overall survival. So again, very robust efficacy leading to confirming its approval. And then we saw data from TROPiCS-02, which looked at sacituzumab in metastatic hormone receptor-positive disease and also showed improvements in both progression free and overall survival. And this was in pre-treated populations of 2 to 4 prior lines of chemotherapy. These agents, again, have established robust efficacy, and so now the idea is can we move these drugs earlier in development into earlier line settings and can we even move these agents into the early disease setting and potentially cure more patients? So hopefully, we’ll figure out ways to make that happen. Dr. Hope Rugo: Yeah, that was a great summary of this exciting data. And I think we really got an idea of what waterfall plots could tell us from DESTINY-Breast01 where you could count the number of patients whose cancers grew with therapy on one hand. It's been a huge advance. I think it’s where we get this “revolution” even in patients with a median of 4 lines of prior chemo, and, in the ASCENT trial, we were able to see this improvement and survival in the hardest-treated subset of metastatic breast cancer triple negative disease. And then the remarkable data in HER2-positive and HER2-low breast cancer hormone receptor positive disease. We’re really covering all of the subset of breast cancers.   When we introduce new therapies though, and of course, our interest is moving them earlier as lines of therapy in the metastatic setting, we really have to think about the adverse events and how those are going to affect their patients, and balancing the risk benefit ratio. Obviously when the benefit is so huge, we’re more thinking about how do we proactively manage these side effects, educate our patients, use prophylaxis when possible. Can you share with us some of your insights on management strategies for toxicities?  Dr. Sara Tolaney: You bring up a very good point, and I will say the ADCs were designed with the idea being that we could deliver a ton of chemotherapy into a cancer cell. So obviously, my hope had been that we weren't going to see a lot of chemotherapy-like side effects because the goal was to try to spare normal cells of these side effects. But unfortunately, we do see that these agents do have real toxicities, and I think that is an important message. So, for example, with sacituzumab, for people who have hair going into it, they will lose their hair during the course of treatment, and so that's important to make patients aware of. It can lower blood counts, and about 50% of patients who are on sacituzumab will end up needing growth factor support while they're on treatment. So, that is again something that needs to be monitored and managed. But usually, we're pretty good at managing neutropenia, and with the growth factor support, I find that it actually works really well.  Another thing with sacituzumab is the potential risk of diarrhea, but most of the diarrhea is low-grade diarrhea. It’s rare that you get someone who has high-grade diarrhea with sacituzumab. Usually, I find it works to just instruct patients to use loperamide as needed. And again, usually that works well. And certainly when needed, dose modification can also help with these side effects and so it is important to keep in mind that this is another option. With T-DXd, one thing that we do have to keep in mind as an unusual side effect is the potential risk of interstitial lung disease. We see that in about 10% to 15% of patients getting T-DXd. That is something that we do have to be very mindful of. For the most part it is low-grade ILD. But there are rare occasions where there have been deaths from ILD. And we're seeing with some of the newer trials, the death rate is usually under 1%, but it is a real potential risk. And so it is really important to counsel patients when getting T-DXd about this potential side effect, that way they are good about communicating with you if they get any new symptoms, such as shortness of breath or dry cough, to get you aware of it and can work it up and get imaging certainly if that occurs.  And then I think the management for ILD is a little unique and a little different truthfully than the way we manage pneumonitis from other drugs. Normally, when I am treating patients who develop pneumonitis, even if it is mildly symptomatic, we often will hold treatment, give steroids, and rechallenge them when it gets better. But with T-DXd, if anyone develops symptomatic pneumonitis, you actually have to permanently discontinue the T-DXd per the guidelines because we just don't know the safety of being able to rechallenge that patient once that pneumonitis resolves. For grade 1 ILD, meaning someone who has, for example, ground glass changes seen on imaging but doesn't have any symptoms, you have to hold the drug and wait until those imaging findings resolve and then you can restart. I usually do treat grade 1 ILD patients with steroids with the hope being that maybe it will allow for the pneumonitis to resolve more quickly, although in truth I don't know if that's the case. I have just taken that approach because I don't like leaving patients off the drug for too long if not needed. Again, I typically treat them with steroids, reimage in three to four weeks, and see if I’m able to restart. If they resolve within 28 days, you can restart at the same dose. If it takes longer to resolve, you need to dose modify.  And then I think the other big thing with T-DXd is to know that it is categorized as a highly emetogenic agent. Most of us are using three-drug prophylaxis, which I think works really well. It is also important to realize that there can be some delayed nausea, which is a little unusual with some of our other agents. And so to warn patients about that and I find that use of olanzapine or ondansetron for the delayed nausea tends to work pretty well.  Hope, do you have any pearls for us? Obviously, you are very experienced in using these agents; are there any things you would recommend for the management of ADCs?  Dr. Hope Rugo: Yes, it's such a great question and an important area because, particularly as we are using these agents earlier, we really need to have strategies for both how long to continue as well as manage the toxicities. I agree with the nausea, olanzapine has been really a great addition, and using a triplet as initial premedication makes a big difference for T-DXd and other deruxtecan ADCs that are in the pipeline. And then I think that the ILD issue, we’re really learning more about the risk factors as well as retreatment. And hopefully, we’ll have more data this year at ESMO Breast and maybe ASCO on retreatment for grade 1. We certainly now do not have any data on the safety of retreatment for grade 2, so that is really not accepted now. For sacituzumab, I think the interesting area is the metabolism and the impact. So with neutropenia, as we move the drug earlier, it's easier and easier to manage, we see less severe neutropenia. We can give growth factors, which we are all good at in oncology. But I think the question about managing diarrhea and who is at risk still exists. Understanding pharmacogenomics and UGT1A1 is an interesting area where patients who have diarrhea could be tested to see if they are poor metabolizers which affects a little under 10% of the overall population. Because in that group, you could give less drug and get the same benefit with less toxicity. So I think this is all very interesting. It is important for providers and patients to be educated so that we can manage this appropriately. And I think you gave an excellent overview.   We have new agents in the pipeline also and maybe we’ll talk about those next, and then we’ll talk a little bit about sequencing and resistance, as well as the unmet need for brain metastases. So lots of areas to talk about. There are a number of TROP-2 ADCs that are in the pipeline, and one that has presented phase III data, datopotamab deruxtecan. But other studies are being developed with new TROP-2 ADCs as well. But then there are a huge number of ADCs there with new targets, for example, immune effector targets, and new payloads, even immunotherapy and two different payloads or bispecific antibodies. And then there is interest in combining ADCs with immunotherapy and PARP inhibitors. We saw data in bladder cancer, I think it was bladder cancer, with combined 2 different ADCs at ESMO in 2023. So a lot of new approaches. How are we going to manage this moving forward? And where do you think we are going to position some of these next sort of "me-too" drugs?  Dr. Sara Tolaney: It's an excellent question, and you're right, the field is exploding with new antibody- drug conjugates. So, it's going to leave us with this conundrum of what to do. And you brought up the really interesting example of the fact that we have an approved TROP-2 ADC, we have as sacituzumab govitecan, and for example, we've recently seen some really exciting data come out from TROPION-Breast01 looking at another TROP-2 ADC, datopotamab deruxtecan or Dato-DXd where that ADC performed better than chemotherapy in a head-to-head trial in terms of progression-free survival in a hormone receptor-positive population. Then there's another TROP-2 ADC, moving forward in development moving to phase III that Merck is developing MK-2870. All three of these ADCs are targeting TROP-2 and have a TOPO 1 payload. So, it leaves you with the question of how do you think about that? Is there going to be a role for using serial TROP-2 ADCs? Could one work after the other, even when they have very similar payloads? How are we going to incorporate them? How do you pick one over the other? So, it is going to be tricky for us as we get more and more of these agents. I think we're all excited about seeing ADCs that may have different targets and different payloads, where maybe we will see that sequential utilization will have robust efficacy if we swap things out. Again, we don't have data here yet, but I think there are other agents in development. For example, you could think of like, disitamab vedotin targets HER2 and has an MMAE payload. So, could it be that someone progresses on T-DXd for HER2-low, but then could go on to disitamab vedotin? How will that work? So, we have a lot to learn, but it's really nice to have so many options.  Dr. Hope Rugo: Yeah, it'll be interesting to see whether or not we select the ADC based on a rational understanding of the tumor and the patient, or whether it's simply what's easier to give and has the right toxicity for that patient.  So, that sort of brings us to our next topic, which is how are we going to sequence these agents? How are we going to understand the mechanisms of ADC resistance? At San Antonio in 2023, we saw a presentation where there was a top-alteration, and the patient had a really long response to a top-directed ADC, or an agent that carried a topoisomerase inhibitor. And that really struck me that we're going to see these alterations. There was a fresh autopsy study that suggested that the alterations may be different in different organ sites of disease. How are we going to figure this out? Dr. Sara Tolaney: Yeah, I also was really puzzled to see those data from San Antonio where we've sort of simplified ADC resistance in our heads to say, well, maybe someone becomes resistant because they lose target expression, or maybe someone becomes resistant because they've developed resistance to the payload, kind of like the way we think of someone developing resistance to getting chemotherapy. But obviously, it's probably far more complex than that. With these ADCs, they need to be able to internalize the ADC and could there be mechanisms of resistance related to the internalization process? So, I think there are lots of potential areas where resistance could be occurring. I think, we don't understand it very well. We've seen patients, for example, who have responded. This is just anecdotal, but we have data, for example looking at, Dato-DXd in the phase 1 triple-negative study where there were some patients who responded despite having progressed on sacituzumab. Well, why is that? You would think if it's target resistance or payload resistance, it would be the same target and a very similar payload. So, why would those drugs work one after the other? And that's why I think we just don't understand this well enough at this point in time.   So, it's clearly an area where more research is needed because it does have significant implications on how we think about using these drugs sequentially. We will need to understand these resistance mechanisms because there do seem to be some rare patients who benefit from these sequencing strategies and then others who don't. So, it would be nice to be able to figure this out and hopefully in the future, we'll be able to test patients and know what drugs to give them. But I think we're far off from that, unfortunately, right now. Dr. Hope Rugo: Yeah, it does seem to be a relatively elusive approach, and I think, in part, it's due to the heterogeneity of cancer. And maybe, as we're better and better at analyzing tumor cells in the blood, which are a rare group, and ctDNA, which, of course, we do now to look for mutations, maybe that'll be an approach that we'll be able to take. And also, of course, moving the drugs earlier into the disease setting with less heterogeneity and mechanisms of resistance might help as well.  I was fascinated by the fact that although the PFS to the first ADC seems to be overall much greater than the PFS to the second ADC, when you sequence them, there are a few patients who have a longer PFS with the second, even if these are just sacituzumab T-DXd sequencing in various directions. So, it's clearly very complex. And right now, I think we're just sequencing and we don't really know how to do it. We just choose what we think is best for that patient first and go on to the next one later, which is interesting. And one of the choices might be treating brain metastases, which of course remains a huge unmet need. And if we could find effective treatment for brain metastases, maybe we could also prevent them in some patients more. What do we know about the central nervous system (CNS) penetration of ADCs and the clinical results? Dr. Sara Tolaney: At first, we were not optimistic that these drugs would have activity in the brain because we thought that these were very large agents that probably couldn't penetrate into the blood-brain barrier. But in fact, I think we were all very excited to see that there is actually data suggesting that these drugs can actually have robust efficacy in the CNS in patients who have active brain metastases. And so what we've seen so far is data with trastuzumab deruxtecan or T-DXd, there have been some trials that have been done, including studies like DEBRA and TUXEDO, which have looked at T-DXd in patients who have active brain metastases and are showing very robust response rates within the CNS. So, we're seeing intracranial response rates on the order of 40% to 50%. And clinically, this is what we're seeing as well. These are smaller studies and there's a larger trial, DESTINY-Breast12, which will hopefully validate the robust efficacy in the CNS with T-DXd. So, again, it's really nice to see this.  To your point, though, one area that I'm curious about, as you were alluding to, is will these drugs be able to prevent CNS disease? And I think that is a very different question because here the blood-brain barrier is not intact when patients have progressive brain metastases, and so these ADCs are causing robust activity. But if you look, for example, and I'll be curious to see what happens, DESTINY-Breast05 is looking at T-DXd in the post preoperative setting for patients who have residual disease and comparing it to T-DM1. And unfortunately, we saw that T-DM1 was not able to prevent brain metastases when looking at data from KATHERINE, where in fact, rates of CNS as the first site of recurrence were similar with T-DM1 and trastuzumab. So, now we'll be interested to see, will it be any different with T-DXd? Will T-DXd be able to have any role in prevention? I think we haven't seen anything like that with ADCs to date, so that would be a paradigm shift in our way of thinking.  Right now, there are strategies being taken from a prevention standpoint of trying to add a tyrosine kinase inhibitor in that early-stage setting, such as what is being done in the COMPASS-RD trying to add tucatinib to T-DM1 to see if that would do it. But again, we really need to understand, again, how these drugs work, particularly when the blood-brain barrier may not be intact. But again, very exciting data with T-DXd in an ongoing trial, actually through SWOG looking at sacituzumab for patients with CNS disease. And we've seen some preliminary data with sacituzumab showing that it actually does penetrate into the brain when they've looked at drug levels in the tumor in the brain, comparing it to plasma, it actually looks similar. So, we know it's getting in there and we'll have more robust efficacy data, hopefully coming soon. Dr. Hope Rugo: Yeah, that was a great summary of that data. It's been exciting also to see some responses in patients with leptomeningeal disease as well, where we've really been struggling with anything that works for more than a few weeks or months at the most. So I'm holding out great hope that we're going to see a big difference because even though TDM-1 had some efficacy, it was nothing like what we're seeing with T-DXd. So we'll see. And the same with sacituzumab with triple negative disease, where sometimes brain metastases can be an isolated site of recurrence, even in patients who have a pathologic complete response. So it has been a big challenge.  So I think that what we've learned from you is a lot about the mechanisms and the data about these new ADCs, the tremendous hope that these are bringing to our patients, but also the really exciting new approaches with new payloads, new targets of drugs that are in development, as well as potentially some different ADCs that have the same target and similar mechanisms of action of this payload. Really fascinating to hear about this, the future work on sequencing, on mechanisms of resistance, and on brain metastases. We have, of course, 2 prospective trials that we'll be looking at sequencing, one with T-DXd and Dato-DXd, and one registry trial with T-DXd and sacituzumab govitecan in the US. So that's also going to, I think, provide us with some important information.  We could talk for a long time about this, but I just wonder if you have any closing comments to sum up your thoughts.  Dr. Sara Tolaney: I think you did a great job leading us through thinking about ADCs, and I think it'll be really interesting to see what happens in the future. While again, these agents have become a standard for us for patients with metastatic disease, I'm going to be curious to see how everything evolves and to see if we'll be able to substitute chemotherapy with ADCs in early disease settings and change outcomes. Will we be able to have novel combinations? Will we be able to sequence these drugs one after another? Will we actually have biomarker predictors to help us sort out which drug to give when? So, still a lot to learn, but clearly a very exciting field right now. Dr. Hope Rugo: Indeed. Sara, thank you for sharing your valuable insights with us today on the ASCO Daily News Podcast on your great work to develop novel therapies for breast cancer. It's always a pleasure to talk to you, and even greater to work with you on the future progress of treatment for breast cancer. Dr. Sara Tolaney: Thank you so much, Hope. Again, really nice to always discuss these data with you. I always learn a lot, so thank you. Dr. Hope Rugo: Thank you. And thank you to our listeners for joining us today. You'll find a link to all of the studies discussed today in the transcript of this episode. Finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts. Disclaimer: The purpose of this podcast is to educate and inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experiences, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of a product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.   Follow today’s speakers:   Dr. Hope Rugo  @hoperugo  Dr. Sara Tolaney @stolaney1     Follow ASCO on social media:   @ASCO on Twitter    ASCO on Facebook    ASCO on LinkedIn      Disclosures:   Dr. Hope Rugo:  Consulting or Advisory Role: Napo Pharmaceuticals, Puma Biotechnology, Mylan, Eisai, Daiichi Sankyo Research Funding (Inst.): OBI Pharma, Pfizer, Novartis, Lilly, Genentech, Merck, Daiichi Sankyo, Sermonix Pharmaceuticals, AstraZeneca, Gilead Sciences, Astellas Pharma, Talho Oncology, Veru, GlaxoSmithKline, Hoffmann-LaRoche AG/Genentech, Inc, Stemline Therapeutics Travel, Accommodations, Expenses: Merck, AstraZeneca   Dr. Sara Tolaney: Consulting or Advisory Role: Novartis, Pfizer, Merck, AstraZeneca, Genentech, Eisai, Sanofi, Bristol-Myers Squibb, Seattle Genetics, CytomX Therapeutics, Daiichi Sankyo, Immunomedics/Gilead, BeyondSpring Pharmaceuticals, OncXerna Therapeutics, Zymeworks, Zentalis, Blueprint Medicines, Reveal Genomics, ARC Therapeutics, Umoja Biopharma, Menarini/Stemline, Aadi Bio, Artio Biopharmaceuticals, Incyte Corp, Zetagen, Bayer, Infinity Therapeutics, Jazz Pharmaceuticals, Natera, Tango Therapeutics, Systimmune, eFFECTOR Therapeutics, Hengrui Pharmaceutical (USA), Sumitovant Biopharma Research Funding (Inst.): Genentech/Roche, Merck, Exelixis, Pfizer, Lilly, Novartis, Bristol-Myers Squibb, Eisai, AstraZeneca, NanoString Technologies, Seattle Genetics, OncoPep, Gilead Travel, Accommodations, Expenses: Eli Lilly, Sanofi, Gilead Sciences