Good day, ladies and gentlemen, and welcome to the Revolution Medicines Third Quarter Fiscal 2021 Financial Results Conference Call and Webcast. At this time, all participants are in listen-only mode. Following management's prepared remarks, we will hold a Q&A session. [Operator Instructions]. Please be advised that today's conference call is being recorded. [Operator Instructions] I would now like to hand the conference over to Peg Horn, Revolution's Chief Operating Officer for opening remarks. Peg, you may begin.

Good afternoon, everyone, and thank you all for joining us today. Joining me on today's call are Dr. Mark Goldsmith, Revolution's Chairman and Chief Executive Officer; Dr. Steve Kelsey, the company's President of R&D; and Jack Anders, our Senior Vice President of Finance and our Principal Accounting Officer. As we begin, I'd like to caution you that our presentation today will contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act regarding the current beliefs of the company with respect to our business. These statements are subject to a number of assumptions, risks and uncertainties. Actual results may differ materially from these statements, and except as required by law. The company undertakes no obligation to revise or update any forward-looking statements. I encourage you to review the legal disclaimer slide we are presenting today as well as all of the company's filings with the SEC concerning these and other matters. During this presentation, we will be referring to a few slides from our corporate presentation. The entire presentation was posted on our website immediately prior to this call. With that, I will turn the call over to Dr. Mark Goldsmith, Revolution's Chairman and Chief Executive Officer. Mark?

Good afternoon, and thank you for joining us. We're very pleased to report that during this quarter, Revolution Medicine's continued building momentum with our targeted therapeutics pipeline, advancing our mission to improve treatments on behalf of patients with a wide range of RAS-addicted cancers, representing some 30% of all cancer patients. Our ambition is, first, to serve the significant unmet needs that remain for patients with KRAS G12C-bearing tumors despite first-generation targeted inhibitors coming online; and second, to deliver first-in-class or best-in-class solutions to benefit even larger numbers of patients with cancers driven by other RAS variants beyond KRAS G12C. Rev Med continues making excellent progress reinforcing our belief that the company's innovative and integrated asset portfolio can drive rational mechanism-based combination treatments for the benefit of patients with diverse RAS-addicted cancers. Today, rather than providing a comprehensive overview of Rev Med's entire pipeline, I would like to take you through a few highlights of several recent significant scientific presentations made by our R&D organization. As a reminder, represented on Slide 5 of our November corporate slide deck, our primary R&D strategy is to advance our emerging RAS on inhibitors to suppress RAS cancer drivers through innovative compounds with superior potential deriving from their unique mechanisms of action and highly differentiated chemical and pharmacologic profiles. I'll update you on these exciting programs momentarily. We also recognize that RAS-addicted cancers are often supported and sustained by various cooperating proteins and cell regulatory pathways that limit the rate or durability of initial responses to targeted therapies. To defeat these oncogenic contributors, we are advancing our collection of high-quality targeted RAS companion inhibitors to deploy in combination with targeted RAS inhibitors in order to enhance clinical benefit. I'll touch on progress we've made in this part of our portfolio as well. RMC-6291 is…

Thank you, Mark, and good afternoon, everyone. We ended the quarter with $609 million in cash, cash equivalents and investments. Turning to revenue; the company recorded a non-cash non-recurring GAAP accounting adjustment that reduced collaboration revenue by $8.5 million during the quarter. This noncash adjustment is a result of adding the RMC-4630-03 study and deprioritizing the RMC-4630-02 study under our Sanofi collaboration. As a result of these events, we revised our estimates of the accounting transaction price and percentage of work performed to date under the collaboration. These revised estimates resulted in a cumulative catch-up accounting adjustment that negatively affected revenue by $8.5 million. Total revenue, including the effect of this non-cash revenue adjustment was $1.1 million for the quarter. Total operating expenses for the quarter increased to $54.3 million, largely driven by research and development expenses, which were $46.5 million. Net loss for the quarter was $52.9 million or $0.72 per share. With regards to financial guidance, we continue to expect full year GAAP net loss to be between $170 million and $190 million, which includes estimated non-cash stock-based compensation expense of approximately $20 million. And with that, I'll turn the call back over to Mark.

Thank you, Jack. We believe that Rev Med is in an excellent position to continue aggressively pursuing our mission on behalf of cancer patients. We have a compelling strategy, a growing set of exciting product assets and a strong balance sheet. We are proud of the tiredless commitment to patients by our organization and are grateful to our patients and their families and the many partners who work with us for providing Rev Med with the opportunity to advance our unique pipeline of RAS (ON) inhibitors and RAS companion inhibitors, which we believe may transform the treatment of RAS addictive cancers in the future. This concludes our prepared remarks for today. And I'll now turn the call over to the operator for the Q&A session. Operator?

Thank you, sir. [Operator Instructions]. Your first question is from the line of Michael Schmidt with Guggenheim. Your line is open.

Hey, guys, thanks for taking my questions. I just had a couple of ones. Maybe first on your KRAS (ON) inhibitors. My question there was if you could remind us perhaps what the KRAS wide type inhibition is of your pancreas inhibitor relative to the mutation selective inhibitors? And related to that, how you envision clinical development next year of RMC-6236 relative to the selective inhibitors like RMC-6291 or the KRAS G12D inhibitor that you mentioned?

Hi, Michael. Thanks very much for your question or your questions. First, with regard to the RAS MULTI inhibitor RMC-6236, it is active on wild-type. And there's really not a differentiation on mutants versus wild type. So it is a multi-RAS inhibitor. And as you know from previous conversations, we view this as a strength and a feature of the molecule in that we know that multiple forms of wild-type RAS can contribute even to tumors that are driven primarily by a mutant form of RAS. And so the ability to suppress both of those does offer a potential therapeutic benefit additive benefit. But as you point out, or as you're implying, it also carries with it some liability in terms of the degree to which you can suppress RAS in normal tissues and still be tolerated. So, I think we'll be operating with some sort of ceiling, but in the evidence that we've generated so far, including evidence that I just described and is covered in the new corporate deck across many different model systems, we've seen quite dramatic antitumor effects at tolerable doses. So, I think that's going to be the name of the game is to find the right dose and schedule in the clinic to maximize antitumor benefit without incurring in tolerability. Your second question is about our clinical strategy for RMC-6236. It's a terrific question. It's about a month of ‘22 too early. I think we'll talk about that as we enter 2022. And as we're really ramping up the activities around the submission of the IND and then moving into clinic, and we will try to share some sort of overview about how we'll approach both RMC-6291 and RMC-6236 in the first half of 2022.

Okay, makes sense. And then, the follow-up on the SHP2 program, for RMC-4630 regarding the pembrolizumab combination study, it looks like, as you said, Sanofi is advancing into an expansion cohort in lung cancer. Any visibility on when you or Sanofi might be able to disclose data from that arm of the study.

Well, as you point out, Sanofi is sponsoring that and so they have the right to make that determination, and we will know about it since we're in close contact with them, but we can't communicate anything about that. We've got to go directly to Sanofi. But as you rightly indicated, they are activating that expansion, and we're looking forward to seeing how that goes.

Okay. And then just one more. I'm not sure if you can answer, but on the trial collaboration around Mirati’s KRAS inhibitor, I guess, in addition to Amgen, is that really just to hedge your bets more or less and cover any of the KRAS inhibitors out there? Or is there more to it to also adding that the trial lineup?

Yes. We've always anticipated that players with RAS (ON) inhibitors will try to access a wide range of potential companion inhibitors. There are differences between all these different molecules that are floating around. And so it makes sense if you own an important RAS inhibitor asset that you would make sure to keep open all potential lines of combination and to evaluate them. So, I think that's very much fulfills our expectation that the leading RAS inhibitors we'll look for a leading SHP2 inhibitor to combine with. And in our view, RMC-4630 is a leading SHP2 inhibitor. And I think this suggests that others think so as well. Practically speaking, from our perspective, what it will do is to help expand the range of perhaps inhibitor set, the SHP2 inhibitor can be combined with and to build a broader data set. But of course, the Amgen study and the RMC-4630-03 study that we've announced will likely get to the sort of the fundamental answer to the question earlier than the adagrasib data. But we're excited to see how adagrasib have pulled into this as well, and it's just lots of parties dancing with lots of other parties, and it will all sort of fell out down the line.

Okay, great. Thanks for taking my questions.

Your next question is from the line of Jonathan Chang with SVB Leerink. Your line is open.

Hi, guys, thanks for taking my questions. Can you talk about how you're thinking about a dose escalation strategy with the RAS (ON) inhibitors as you prepare to enter the clinic next year? Have you received any sort of regulatory input on this? And how might that inform how soon we could see initial proof-of-concept data from those programs?

Yes. So I think, thank you, Jonathan. Nice to talk with you, and thanks for your questions. As I mentioned in the early part of 2022, we'll start to lay out more information about how we'll approach the development, the clinical development of RMC-6291and RMC-6236, I'm not sure that there's something specific on the question of dosing and dose escalation that you're trying to ask about. Is there something kind of narrower that you can clarify?

Any more sort of granular thoughts on, I guess, just trying to back out when we might see initial efficacy data from those programs?

Okay. So it's really a timing question. It's a good question. I'd say hold that again a couple of months ahead of us in terms of the question that you're asking, but we'll try to be forthcoming on that point in the early part of 2022, as we lay out the overall strategy for development.

Understood. And just maybe one last question for me. Can you discuss the considerations for choosing your next RAS on development candidate. Thank you.

Right. Well, our process here reflects the fact that we have multiple programs running in parallel. We sort of select some to talk about, but we certainly don't talk about all the things going on. It's a very leveraged drug discovery process, meaning that each of the programs is learning from each of the other programs. So as soon as one thing advances, we gain knowledge that gets fed into all the other programs. And there's just sort of a constant shuffling going on, particularly in lead optimization, where you're trying to optimize against a variety of different parameters. It's always hard to predict on a given day, when those parameters will all come together in the optimal molecule. And so, we don't really make a decision about a molecule until we make a decision. So we have all the data. And it's up to the teams to determine the pace of that based on those data packages that are brought forward. So to a large degree, it's driven really by, if you will, a bit of an internal competition, but really a set of standards that each program has to meet. And when it needs those standards, the packages get presented and we make a decision about whether to move something forward or not. And so far, we've not made decisions where we decided to sort of hold one thing back and move something else forward. We've just been fortunate to be able to advance the molecules that are being proposed to advance, and it just happened to be RMC-6291 and RMC-6236, which were proposed on the very same day last year and affected on the very same day. But there isn't sort of a hyper strategy to prioritize in terms of advancing molecules. That's not to say that there isn't a strategy around which targets we prioritize in the discovery process. We, of course, can't work on 36 targets simultaneously. We work on a smaller number than that. So there is some prioritization that's going on there. But at the end of the day, it's just when the data packages become available and we evaluate them quite quickly and make a determination about whether something qualifies to events.

Got it. Thanks for taking the questions.

Your next question is from the line of Eric Joseph with JPMorgan. Your line is open.

Hi, good afternoon. Thank you, guys for taking the questions. Maybe just a follow-up on Jonathan’s... I'm wondering whether from your in dose range finding studies or pre-IND work with RMC-6291, whether you can sort of talk a little bit about sort of the anticipated dosing interval or preclinical profile, whether you anticipate any having to evaluate intermittent dosing when the Phase I gets underway. And then, following up on the Sanofi-Mirati collaboration. Do you have a sense of how much of the local indications in their Phase I/II study might overlap with your RMC-4630-03 trial or with Amgen’s Lumakras or sotorasib

Okay. Hi, nice to talk to you. Thanks for your questions. With regard to RMC-6291, Steve, do you want to comment? The question was about are we planning daily dosing versus intermittent dosing and how well everyone…

For RMC-6291?

For RMC-6291. That was the question, if I…

Sure. I think what we're learning from the current information coming in, particularly from the sotorasib and adagrasib programs is that you need to really continuously cover the Mirati's G12C for as long as you -- and as hard as you possibly can. And so in that respect, it is unlikely that some form of intermittent dosing schedule will be deployed with RMC-6291, which has at least as good selectivity against G12C, the Mirati's G12C is going to wild-type RAS. So we're not anticipating having to deploy an intermittent dosing strategy with RMC-6291 or indeed with any of our truly new and selective RAS (ON) inhibitors that we bring forward behind RMC-6291. It's a strategy that I think works very well for inhibitors that inhibit wild-type RAS pathway signal in. I'm not sure that it's either necessary or even desirable for the mutant selective RAS (ON) inhibitors.

Okay, that makes sense. From the preclinical profiling work that you've done, do you have a sense of whether you have coverage for once-daily dosing versus twice daily?

The preclinical profile of RMC-6291?

Correct.

Yes, it's very difficult to predict that. I mean, we've run the usual sort of allometric scaling and what have you. We're still waiting for some data to come in. So it's not complete yet. The default, I suspect, will be once daily dosing. But once we get to big clinic, we'll have to revisit at and see whether that's still the best thing to do. I mean, we have quite a lot of flexibility there. But for now, I think it would be safe to assume that, that's a good starting position, but we, of course, reserve the right to change our mind as information becomes available to us in the clinic.

Understood. And just coming back to the Sanofi-Mirati collaboration. What is -- can you just kind of talk about what's complementary to the Lumicast combination with RMC-4630 versus potentially redundant?

Yes. If I might just add something on the issue RMC-4630-03 [ph] versus G12C dosing on RMC-6291 just to return to that briefly. And that is just keeping in mind that the RAS, the dynamics of inhibiting RAS (ON) versus the dynamics of just inhibiting RAS (OFF) may be very different. And I know, Eric, you and I have talked about that in the past that we have this immediate and complete cessation of RAS signaling from KRAS G12C when we hit it with a RAS (ON) inhibitor as opposed to the requirement for sustained accumulation of RAS (OFF) in the compound bound form, which is required for RAS (OFF) inhibitors were. So, it's really -- it's not really an apples-to-apples comparison, if you're sort of thinking about the paradigm for adagrasib and sotorasib and the other RAS (OFF) inhibitors versus RMC-6291, it's a different paradigm. Nonetheless, I think Steve's answer was very clear about what we believe is the default assumption here. And if we're informed otherwise in the clinic, we'll react to it. I think with regard to CodeBreaK 101 and Eric, well, you've asked sort of both questions. So maybe you could comment on Steve, kind of Part A was how does it differ versus how is that complementary to CodeBreaK 101c? And then, the second question was what about the Mirati's KRAS G12C [ph]?

Yes. The RMC-4630-03 study, which is the combination study with sotorasib was deliberately designed to be different, but yet complementary to the lung cancer component of CodeBreaK 101c. It is different; we learned from some of the public data with regards to how to divide up the cohorts. As you know, I mean, there are essentially two predefined cohorts in that study. One, which is essentially restricted to patients who have G12C mutations and co-mutations in other genes that might alter the response to either sotorasib or even RMC-4630. So that allows us to evaluate those arms separately. There are some other subtle differences as well, which may become important. Firstly, the number of lines of prior therapy is restricted in the RMC-4630-03 study, which is not in CodeBreaK 101c. And then the probably the more obvious operational difference is that the lung cancer arm of CodeBreaK 101c is restricted to the United States, where the RMC-4630-03 study will enroll a substantial portion of patients outside the United States. I don't think that's going to make any difference to the ultimate valuation or availability of the data set. The Mirati combination is we see it as hugely complementary. We see Firstly, as Mark said, it's inevitable because RMC-4630-03 is a companion inhibitor for all RAS inhibitors and adverse asset is one of those RAS inhibitors. And it's complementary, and it's both neighboring as well because at the very least safety data from that study will enable us if we wish to move very quickly into more advanced trials should that become desirable with in combination with adagrasib. So, I think it's all part of the rich tacistry [ph] of using RMC-4630-03- as a companion for RAS inhibition. I think we're very focused right now on G12C because, of course, those are the two, the more obvious clinical RAS inhibitors inhibit G12C. But this, of course, is going to become incredibly important later as we get inhibitors of in KRAS mutations that were not G12C. And we very much hope to be first into the clinic with those at some future date.

Okay, got it. Thank you very much for the questions.

Your next question is from the line of Marc Frahm with Cowen & Company. Your line is open.

Hey, thanks for taking my questions. Maybe, Steven, on your last comment about safety read across from trials and that that's very much an ongoing process. Are you able to update the CodeBreaK trial, has that now selected a recommended Phase II dose? Or with that target dose of 200 milligrams day 1, day 2? Or is that still not quite finalized yet? And then related to that, is in the RMC-4630-03 trial because of the recommended Phase II dose hadn't been selected when you were opening that up, there's a safety run-in period. Has that safety run-in period been complete on your end? Or are you able to skip it given the evolving safety data within CodeBreaK?

Hi, Marc, thanks for your questions. So with regards to Lumakras, as you know, we're not the sponsor of that CodeBreaK 101c study. So that disclosure needs to become driven by Amgen. So we don't have any update on that. And then with regard to the 03 study, we just started that we announced the study in August, and we just today are now indicating that it's actively recruiting. It would be fantastic if we could tell you that we had already recruited and dosed enough patients to have selected a dose or the completion the dose running, but that wouldn't be true. So I can't say so but I think we'll be informed by the selection of that dose when Amgen is able to disclose. If they do not disclose the dose publicly while we're dosing in the running, we'll go at 140 milligrams and then we'll bump up to 200 milligrams. So I think we're still in the same paradigm that we were in a few weeks ago or a couple of months ago, and we'll update you when there's -- when we are able to give you a material update on that.

Okay, that's helpful. And then, just in terms of the guidance to -- from the 03 trial to potentially disclose some results in the back half of next year, is that your mind likely to be just kind of the data from that safety run-in period? Or should we think broader than that?

Yes, that's a good question. I mean, what we intended to communicate was that our ambition, our aspiration is to have high-level findings from the activity of the combination, antitumor activity by the end of next year. Obviously, that depends on how quickly we ramp up enrollment. But I don't think it's really strictly going to be driven by that short run-in. And I think it's driven by the desire to have a larger number of patients, which is really the whole purpose of that study is to get to that kind of range of [indiscernible] split between the cohort without on so many patients in the cohort with mutations, not necessarily not necessarily split evenly, but split between those two. So that's the kind of data we're really looking for. I think the run-in to us is a relatively modest kind of early piece, but we hope to generate more substantial data throughout the year. But of course, everything depends upon enrollment, and it's very hard to predict the exactly enrollment rates before we enroll patients. So our best guess is by the end of 2022, we'll be in a position to share something.

Got it, thank you. Very helpful.

You bet.

Your next question is from the line of Chris Shibutani with Goldman Sachs. Your line is open.

Thank you very much, and apologies in advance. I'm hopeful there won't be too much background noise, I'm at a train station. Mark and Steve, there were 2 questions that I had one on the colorectal cancer opportunity. I believe this is some new data that you're sharing precinct in terms of 6291 and 6236. I'm curious to know how you're thinking about the opportunity set and the strategy, particularly in view of clinical data that's been unfolding, particularly for instance, with the EGFR combinations that are ongoing with your view on the opportunity, what's your strategy looking on?

Yes. Thanks, Chris. Appreciate your going to trouble calling in despite being on the road. Thank you so much. Colorectal cancer, Steve, I think you probably will want to comment about this in terms of recent data.

Yes. I mean, firstly, Chris, as you know, just under half of colorectal cancers are actually RAS mutant and it's a really nasty disease to have. So in the context of serving an unmet medical need, it's a really high priority for us. We are encouraged by the 6291 data in RAS mutant colorectal cancer. And whether or not RMC-6291 as a single agent has enough punch there to really do justice to patients. We'll wait and see. But I think what you're angling at is ultimately that we are prospectively planning to combine RMC-6291 with companion inhibitors in colorectal cancer. And we have a number of those in our portfolio, and we're certainly not afraid to do a clinical trial in combination with one of the anti-EGFR antibodies if it comes to that. It's a very -- we expect RMC-6291 to have a reasonably clean selectivity profile. So we don't anticipate there being overlapping toxicities with EGFR inhibitors, and that's a completely legitimate path forward for G12C mutant colorectal cancer. Now of course, the big unmet medical need in colorectal cancer is in the other G12 mutations because most RAS-mutant colorectal cancers are either G12D mutation or G12V mutation. And I think that's where the impact of the RMC-6236 data comes in. We've seen very impressive responses in RAS-mutant colorectal and pancreatic cancer with single-agent RMC-6236.And we have no hesitation in testing IMC-6236 as a single agent in RAS mutant colon cancer once we get to that point. Because RMC-6236 has RAS-wild type activity, it does restrict the combinations that we may be able to use a little bit. But nevertheless, there is a very active combination preclinical program ongoing, which we haven't disclosed yet and will do in due course. But I think in general, what you can expect to see is pretty much what we have already observed with the KRAS-OFF inhibitors, which is there will be some single-agent testing. If it packs a punch, then that will be great. And then the combinations will move forward to try to optimize on the clinical benefit.

Great. And the second question, if I may. One on strategy I'm sorry, Mark, did you want to add some comments, please do.

Yes. I was just going to build on Steve's good comments there. There probably is also an advantage to 6236 in its wild-type anti-RAS activity, which I alluded to earlier with Michael's question, and I think that could come into play in colorectal cancer. And the -- where we know that other forms of RAS do step in and contribute, that's, I think, quite well established now. So we're quite excited about the data sets in colorectal cancer for 6291 and 6236 and I appreciate you're highlighting that. And I think there's real opportunity there.

Great. And then, if I could follow with a strategic question. You guys have -- it's really strategy and capacity. So in the past, you've done a number of partnerships, including with Amgen, Sanofi, for instance, there's pros and cons of doing these approaches. Maybe somebody else gets to pay the bill, but then they also have control, perhaps better of communication, puts you through the shareholders or patients and whatnot. As you sit here in November '21, the RAS-ON portfolio certainly seems to be coming into its own. And some of the earlier questions also, we're trying to contemplate how much you guys felt you could do on your own versus others until -- if you did a partnership? What's the most important priority for you? Or are you thinking now that you're going to do it alone for a while as we insert into that a [indiscernible] new for your competitor conference in January.

Great set of comments, Chris. I appreciate everything you said and agree with it all. As to our posture, I think we are fundamentally viewing the RAS-ON inhibitor opportunity is seeing a RevMed opportunity. I think we're leaders there. We're pumping out these molecules at an astonishing rate and a high-quality molecules, and the preclinical data are continuing to kind of affirm the commitment for us because of the kinds of success we're seeing. So, we're not particularly anxious to get into the complexities of partnerships around these assets. If we do it, it would be very narrow, I could imagine a single asset partnership, but I don't think it's necessarily likely that we would do it, but I can imagine it. And -- but I think a big feature here, and you alluded to this in your remarks is that it does actually take extra bandwidth for us to enter partnerships that can complicate our own strategic activities because we have to now make decisions in concert with somebody else's strategic vision, which almost inevitably is not the same as ours. That's just the nature of 2 companies, they will have different views. And so there is a certain amount of heat that just gets generated that we have to support just in doing a partnership. And so at some point, you then wonder whether or not the net benefit is there. But at the same time, we are expanding our programs. We have 2 more compounds going into the clinic, that we'll have 4 in the clinic in 2022. And I expect there will be more after that. And so our pipeline is getting very big, costly, and if we talk about the combinations, which has been off of that at another level of complexity. So there is always going to be a voracious appetite for supporting that with personnel and things that cost money. So we'll see. But I would say our default assumption is that there would not be a partnership anytime soon, but there has been significant interest inbound. And we'll see if we can design something that's optimized for us rather than for somebody else.

Great. Thank you both for your thoughts [indiscernible] talk to you soon.

And your last question is from the line of Ben Burnett with Stifel. Your line is open.

Hey, thank you very much. I was wondering if you could just offer maybe just a little bit more color on some of the strategies that you might be able to employ with regards to the RAS-multi RMC-6236, just what you can employ clinically to optimize the therapeutic window, if needed? And then I have a quick follow-up.

I assume Steve wants to comment on that.

Oh, 6236, yes, we tried hard to message this because of the initial wave of concerns that we had over anything that hits wild type RAS being toxic. There are a number of ways that we are going around optimizing the therapeutic index RMC-6236. The first and most obvious is that we think it's inherent in the fact that tumors with RAS mutations are addicted to mutant RAS there will be a therapeutic index because I think -- and I think that the more information you see from sotorasib and adagrasib that, that becomes increasingly clear. Tumors with mutant RAS seem to be highly dependent on it. And if you switch that off, then they tend to implode to at least to some extent. So, we do expect the tumor to suffer more underexposure to RMC-6236 in normal tissue. There are, as we've alluded to in some of our previous disclosures, certainly recent disclosures ways of scheduling RMC-6236 that can improve the therapeutic index. So I think it gets back to this concept of intermittent dosing, where -- but I think it's important to point out RMC-6236 is a very unique molecule in as much as the pharmacokinetics in tumor seems to be different from the pharmacokinetics in normal tissue. And I think that has something to do with the binding of RMC-6236 to the intracellular chaperone cyclophilin A, which on a net basis, across tumors seems to be more abundant than in normal tissue counterparts. So -- what you see is a sort of residence time of RMC-6236 in tumors, which greatly outstrips the residents in the normal tissue. And what that ultimately results in is that the intermittent dosing that may be deployed in the clinic actually only results in intermittent inhibition of RAS in normal tissues. And not intermittent dosing of RAS in tumor tissue, which ultimately creates a quite a significant therapeutic index because the dynamics of RAS within tumors and the way the RAS pathway signaling is inhibited, diverge very dramatically with quite subtle changes in the intracellular exposure. So on top of that, I think we can harness the immune system. We've already disclosed some data on how RMC-6236 significantly changes the tumor microenvironment in a way that would favor the antitumor effect versus any inhibition on normal tissue. And then ultimately, if we need to preferentially enhance the antitumor activity of IRMC-6236, we can combine it with something that has a selective antitumor effect and something which even potentially has a synergistic effect. And there are a number of things that we're testing right now in that respect. So I think the direction in which we're heading. We're confident that we will achieve a therapeutic index in RMC-6236. And that's clearly -- the nature of that how it's manifest is going to vary probably from patient to patients and from patient population to patient population. But there are a number of strings we can pull and we're pulling all of them.

Okay. That's super helpful, fascinating. Just one other quick question. Is there -- like what is the relevant potency KRAS inhibition between the 6236, the multi-RAS inhibitor with the G12C specific inhibitor. And I guess what's motivating that, you showed some preclinical data of the multi-RAS inhibitor that looks like it was done at a lower dose to the G12C inhibitor. I think 25 mg per kg versus 200 mg per kg. And so I guess I was just wondering, is the multi-inhibitor more potent than the G12C.And if not, I guess, could you just comment on the choice of dose for those assays?

Yes. The potency as measured in the sort of the classical in vitro systems against G12C is not terribly different between RMC-6291 and RMC-6236. And in the context of how you might deploy RMC-6236, there is still some possibility that it would have utility in patients who have tumors harboring a G12C mutation. It's not entirely clear to us at this stage how we will develop RMC-6236 in patients with G12C mutations as opposed to the other G12 mutations or indeed the other KRAS mutations. And as Mark said, we'll go into that in a bit more detail, in the early part of next year. With regards the dosing paradigm, I mean, right now, we are dosing RMC-6236 in our preclinical models at a dosing schedule, which is well tolerated and which has profound antitumor activity against all of the RAS mutations that we show you in the slide deck today. It is quite possible that the some of the antitumor activity that we are seeing with RMC-6236 is due to the inhibition of feedback through wild-type RAS. It is not completely restricted to its profound inhibition of the mutant RAS. And so it's very hard to compare RMC-6236 and RMC-6291, they're very complementary compounds. And in fact, in the long-term strategy, it is quite possible that RMC-6236 could be a very useful companion inhibitor for a RAS mutant selective inhibitor like RMC-6291. So I don't think we want to -- we see this is very complementary compounds marching forward together. And for all we know, they may well be useful in combination in G12C [indiscernible].

And if I could add to that, I think that's really well put, Steve, with regard to G2C. And as you mentioned earlier, as Steve mentioned earlier, that concept extends to other mutant selective inhibitors of other targets. And we just shared with you today and recently, data, for example, on our oral highly mutant selective KRAS G12D inhibitor, which is coming just behind RMC-6236. And we really don't see those as mutually exclusive, they could end up converging. It's quite a remarkable bit of biology that's going on here, and we're trying to create a master clinical toolkit, if you will, of compounds that are -- that have special features. And sometimes those features are particularly useful for killing tumors. And if we can put them together in the optimal way, we'll have the greatest impact for patients.

Interesting, thank you.

As I see no further questions at this time. That concludes the question-and-answer session for the call. I'll now hand the conference back to Dr. Mark Goldsmith for final comments.

Well, thank you, operator, and thank you to everyone for participating today. We appreciate your continued support of Revolution Medicines.

This concludes today's conference call. Thank you for joining. You may now disconnect. Stay safe.