Good morning. My name is Maxine, and I'll be your conference operator today. At this time, I would like to welcome everyone to the Blueprint Medicines 3Q 2021 Financial Results Conference Call. All lines have been placed on mute to prevent any background noise. After the speaker's remarks, there will be a question and answers session. If you would like to ask a question during this time, simply press star followed by the number one on your telephone keypad. If you would like to withdraw your question, press star followed by the number two. Please plan to limit yourself to one question. Thank you. Kristin Hodous of Blueprint Medicines, you may begin your conference. Thank you, operator. Good morning, everyone, and welcome to Blueprint Medicines' third quarter 2021 financial and operating results conference call. This morning, we issued a press release which outlines the topics we plan to discuss today. You can access the press release, as well as the slides that we'll be reviewing today by going to the Investors section of our website at www.blueprintmedicines.com. Today on our call, Jeff Albers, our Chief Executive Officer, will discuss Blueprint Medicines' third quarter 2021 business highlights. Christy Rossi, our Chief Commercial Officer, will provide a commercial update. Fouad Namouni, President of Research and Development, will review our recent clinical progress and highlight upcoming milestones across our growing pipeline. Mike Landsittel, our Chief Financial Officer, will review our third quarter 2021 financial results. Becker Hewes, our Chief Medical Officer, is also on the call and will be available for Q&A. Before we get started, I would like to remind everyone that statements we make on this conference call will include forward-looking statements. Actual events or results could differ materially from those expressed or implied by any forward-looking statements as a result of various risks, uncertainties, and other factors, including those set forth in the Risk Factors section of our SEC filings. In addition, any forward-looking statement made on this call represents our views only as of today and should not be relied upon as representing our views as of any subsequent date. We specifically disclaim any obligation to update or revise any forward-looking statements. Now, here's our CEO, Jeff Albers. Thank you, Kristen, and good morning, everyone, and thanks for joining us today. In the third quarter, we made tremendous progress toward bringing our life-changing precision therapies to patients around the world. Today on our call, you'll hear about three areas of fundamental growth. The first is solid commercial performance anchored by AYVAKIT's advanced systemic mastocytosis launch in the U.S. We're seeing broad demand from prescribers at both academic and community centers and across patients with different advanced SM subtypes. This momentum provides a foundation for continued leadership and growth for our SM franchise as we look to deliver top-line data from our pivotal PIONEER study of AYVAKIT in non-advanced systemic mastocytosis in mid-2022, and accelerate development of BLU-263, our next-generation KIT inhibitor. The second area of growth is based around the continued execution and expansion of our R&D vision, with a robust pipeline of innovative precision therapies advancing at all stages of development. As Fouad will describe, our next wave of clinical programs is progressing rapidly towards multiple proof-of-concept readouts. We've been encouraged by widespread interest in our SYMPHONY trial of BLU-945, and we're on track to initiate a phase I trial for BLU-701 in the fourth quarter. Beyond our EGFR franchise, we continue to expect BLU-222, our CDK2 inhibitor, and BLU-852, our MAP4K1 inhibitor, to advance into clinical development next year. A third area of strength is our current financial position, which, as Mike will describe in more detail, enables us to drive revenue growth across multiple domains, invest in a range of high-value R&D programs, and continue to build a world-class company with integrated global capabilities. For some time, we've talked about the promise of diverse revenue streams across the strategic pillars of our business. This diversity is now truly coming into view as we're able to increase our full-year revenue guidance based on activity throughout our portfolio, both independently driven and through our strategic collaborations. Combining our prolific scientific platform and commercial execution with the financial and organizational strength to bring in external assets, we're well-positioned for Blueprint to be the leading driver of innovation in precision medicine for years to come. With that, I'll turn the call over to Christy to discuss our commercial efforts. Christy? Thanks, Jeff. Good morning, everyone. Let me start by sharing our third quarter results. Our AYVAKIT net product revenue was $17.3 million. Net end user sales of GAVRETO, as reported by Roche, were $5.5 million for the quarter. As a reminder, the booking of GAVRETO sales shifted to Roche at the beginning of the quarter. Q3 was our first full quarter of the AYVAKIT U.S. launch in advanced systemic mastocytosis, and the positive early trends we have been seeing reinforce our view that SM, across advanced and non-advanced forms of the disease, is the most significant near-term opportunity that we are pursuing at Blueprint Medicines. As I reflect on the launch dynamics to date, a key theme that gives me confidence is breadth. Breadth of prescribers, accounts, and patient types. Let's start with the breadth of prescriber and account activity. As I've shared previously, a key focus area for Blueprint has been engaging with SM centers of excellence in key accounts where patients are more concentrated. Over the first few months of the launch, our efforts to engage these centers have gained good traction, with approximately two-thirds now utilizing AYVAKIT commercially. As we continue to focus here, we also know that many patients are cared for in a community setting and that prescriber education and patient identification there will be critical to the long-term trajectory of the launch. With that in mind, I'm very encouraged that approximately half of our volume is coming from community prescribers and accounts. Overall, through the end of Q3, we have had more than 100 new prescribers or accounts utilizing AYVAKIT for the first time since our approval in advanced SM. This prescriber breadth will catalyze our ongoing efforts to identify more advanced SM patients and ensure they have access to AYVAKIT therapy. We are also seeing breadth of AYVAKIT utilization by patients across their advanced SM treatment journey. We continue to see a fairly even mix of patients switching from other therapies and those who have no indication of a prior advanced SM therapy. We will gain additional insight into these patient dynamics as we move through the launch, but this early data suggests that AYVAKIT is being used among the prevalent pool of diagnosed advanced SM patients, as well as in newly diagnosed incident patients. Finally, we are pleased that the demand we are seeing has been supported by strong patient access to therapy and a rapid time to fill prescriptions. In total, this combination of increasing prescriber and account breadth, new patient starts, and the long durations of therapy we expect based on our clinical trial experience, form a foundation for longer-term revenue growth. As we continue to execute on our launch in advanced SM, we are also focused on building our leadership position in SM more broadly. A key priority is increasing disease education and patient identification so that more patients who are suffering from SM can be diagnosed and offered appropriate treatment. I'm very excited about progress we've made in the third quarter to increase access to testing, which is critical to achieve this goal. We've initiated a partnership with Labcorp to make highly sensitive blood-based KIT D816V testing available for patients across the United States. Testing is now widely available and accessible through our sponsored testing program to qualifying patients where an SM diagnosis is suspected. We anticipate that the widespread availability of testing will help to improve the rate of diagnosis in the U.S. and facilitate improved access to care for patients. Overall, we've taken important steps this quarter towards realizing the potential we see to transform care for SM patients globally. I'm excited about the road ahead as we continue to execute on the U.S. launch and look to planned global launches in advanced SM, the readout of PIONEER next year, and the opportunity for AYVAKIT in non-advanced SM, and of course, our ongoing development of BLU-263. Let me now turn to GAVRETO. As we've mentioned, a key strategic rationale for our collaboration with Roche and Genentech was that it enhanced our ability to reach more patients globally. We're excited to begin to see this come to fruition. In the U.S., we continue to focus our efforts on expanding the RET inhibitor market through increasing comprehensive and actionable biomarker testing rates at diagnosis. We were pleased with the continued growth we saw during Q3, bolstered by strong momentum coming out of ASCO, where we shared updated data on treatment-naïve patients from the ARROW study. During the third quarter, we also received a positive CHMP opinion for GAVRETO in a line-agnostic non-small cell lung cancer setting. An approval in this indication would be a competitive advantage in the E.U. territory for GAVRETO. This, combined with the multiple planned regulatory applications that Roche is pursuing in additional geographies and the ongoing strong launch of GAVRETO in China by our partners at CStone, provides a clear roadmap for global revenue growth. With that, I would now like to turn the call over to Fouad to review our clinical portfolio. Thanks, Christy, and good morning, everyone. Earlier this year, I shared the broad R&D vision to position Blueprint Medicines as the world's leading precision therapy company. This included three areas of focus. Therapeutic area leadership in precision oncology and hematology with a near-term focus on systemic mastocytosis and lung cancer. Innovative drug development, including the creative use of trial designs, translational data, and regulatory strategies to bring our therapies to patients faster. Continuous scientific leadership through the productivity and the expansion of our research platform. I'm excited to update you today on the very good progress that our R&D team has made towards realizing the vision across our portfolio. First, we continue to expand our leadership in systemic mastocytosis through robust execution of our KIT programs. For AYVAKIT, our registration-directed PIONEER study in non-advanced SM is on track to deliver top-line results in the middle of next year. For BLU-263, our next-generation KIT inhibitor, the phase II/III HARBOR study, also in non-advanced systemic mastocytosis, is now underway. In the third quarter, we began patient screening in the phase II portion of the study, carrying forward momentum as we wind down PIONEER enrollment. As a reminder, HARBOR is enrolling a broad population of patients with non-advanced SM, including patients with milder forms of the disease. Combined with the encouraging commercial launch of AYVAKIT in advanced SM, these studies position us to dramatically improve the standard of care across all forms of systemic mastocytosis. Second, we have significantly advanced our clinical program in EGFR-positive lung cancer. For BLU-945, patient enrollment in the SYMPHONY trial is accelerating with significant and growing demand at multiple clinical sites. As the dose escalation phase of the study is moving rapidly, we are now planning combination expansion with third-generation EGFR inhibitors such as osimertinib next year. This approach will accelerate and expand our development effort across multiple patient populations. We are also happy to report that we expanded the trial's global scope with now a clinical trial agreement in place for Japan. This represents an important milestone towards building a robust trial footprint for our EGFR therapies in Asia. For BLU-701, we have submitted an IND application to the FDA, and we are on track to initiate a phase I/II study in the fourth quarter. Similar to the SYMPHONY study, we plan to explore combination development early in this study, including with BLU-945. Furthermore, preclinical data continue to support our clinical development strategy. We have recently completed studies generating compelling data on the potential of a BLU-945 and BLU-701 combination, which we are submitting for presentation at a scientific meeting in early 2022. Finally, our early-stage research pipeline continues to flourish. In recent months, we have rapidly progressed BLU-222, our selective CDK2 inhibitor, through IND-enabling work, and we now anticipate it will enter the clinic in the first quarter of 2022, earlier than previously expected. More broadly, we have also nominated multiple undisclosed research programs this year. These include a number of exciting targets with the potential to further expand our scientific leadership in precision oncology and hematology. As these programs progress through discovery research, we look forward to sharing more information on another wave of therapeutic candidates. I would now like to turn it over to Mike to discuss financial updates. Mike. Thanks, Fouad. Earlier this morning, we reported detailed third quarter financial results in our press release. For today's call, I'll touch on a few highlights from the quarter. First, as we head into the fourth quarter, Blueprint continues to build on our strong financial foundation through a range of revenue sources. In addition to our growing base of global revenues from AYVAKIT and GAVRETO sales, progress across our multiple strategic collaborations is expected to meaningfully contribute to our fourth quarter revenues. Based on increased anticipated milestone and other collaboration payments, including the acceleration of potential milestone achievements into the fourth quarter, we are raising our annual revenue guidance for 2021 to between $170 million and $180 million. In the third quarter, total revenues were $24.2 million, including $17.3 million of net product revenues from sales of AYVAKIT and $6.9 million in collaboration revenue. Collaboration revenue for the quarter was primarily driven by commercial supply shipments to our partners, CStone and Roche, as well as royalty revenue for sales of GAVRETO and AYVAKIT by CStone in China. As a reminder, U.S. GAVRETO sales are now being booked by Roche, with our share of profit or loss appearing on our income statement. Our total operating expenses in the third quarter increased slightly compared to the second quarter of 2021, driven by continued growth in R&D expenses as we bring multiple programs into clinical development. Over the next few quarters, we anticipate that investment in our promising early-stage programs, as well as our commercial efforts with the ongoing launch of AYVAKIT in advanced SM, will continue quarter-over-quarter operating expense growth. Finally, we ended the third quarter with nearly $1.3 billion in cash on hand, ensuring that we have sufficient resources to invest in our pipeline. Overall, this combination of growing product revenues and progress through our collaborations fortifies our exceptionally strong financial position, allowing us to focus on execution across our portfolio as we enter another transformative period of growth for the company. I would now like to turn the call over to the operator for questions. Operator? At this time, I would like to remind everyone, in order to ask a question, please press the star followed by one on your telephone keypad. Please plan to limit yourself to one question. Our first question comes from Salveen Richter from Goldman Sachs. Your line is now open. Hi, everyone. Thanks for taking the question. This is Andrea on for Salveen. Congratulations on the quarter. Christy, maybe a question for you. Just wondering if you could speak a bit more on your partnership with Labcorp and how you expect this to expand the potential addressable population. Very quickly, if you're seeing any utilization in non-advanced patients at these centers of excellence. Sure. We're, you know, quite excited about the partnership with Labcorp. Throughout this year, building capability and making highly sensitive blood-based KIT D816V testing available in the U.S. has been a key strategic focus of ours. As I've discussed before, we believe blood-based testing will greatly facilitate access to diagnosis for patients, particularly for non-advanced SM patients, where that diagnosis may be suspected. The partnership with Labcorp has this testing available commercially, so that in and of itself will be very helpful for, you know, prescribers who use Labcorp nationally. We have a sponsored testing program that is available, where if a patient is suspected of having an SM diagnosis, they can receive access to testing through Blueprint. We believe that this will reduce the potential barriers and hurdles for patients to access testing and also ensure that if a, you know, a provider suspects SM, they utilize the appropriate type of testing so that the results that they get can be trusted. We're really excited about this as a step forward. In terms of utilization of AYVAKIT, our best understanding continues to be that, you know, patients who are being prescribed right now are advanced SM patients by and large. We, of course, don't have perfect visibility into every patient, and as I said before, the, you know, diagnosis and subtyping in SM is complex to say the least. But certainly that's our understanding based on the intelligence we have from speaking to healthcare providers. Great. Thanks so much. Our next question comes from Reni Benjamin from JMP Securities. Your line is now open. Hey, thanks guys for taking the questions and congratulations on a great quarter. Can you just give us a breakdown of maybe GIST versus SM in terms of the AYVAKIT revenues? And can you just also give us an update on the Tapestry study and if PIONEER enrollment is completed? Because I think to meet this deadline, at least by our calculations and the follow-up that's required, I would think enrollment had to have completed in the third quarter, but I'm not too sure. I might have my calculation off here. Thanks very much. Yes. Christy, why don't you take the first half and Becker take the second half. In terms of revenue, you know, we obviously did not provide a formal breakdown in terms of indication splits, but as you've seen, if you kind of look historically and as we've discussed, you know, GIST has been, I would say, a relatively consistent revenue stream for Blueprint at this point. When we look at quarter-over-quarter growth, it's really coming from advanced SM primarily as well as a little bit of international as well. Advanced SM is really the key driver if you look at quarter-over-quarter growth. With respect to the two trials, you mentioned Tapestry, again, we're transitioning to Roche, and there continues to be enthusiastic interest in getting multiple tumor types into this study. With respect to PIONEER, we have, as I mentioned on the last call, the process is to screen patients and make sure that the patients with the right TSS score severity of disease are enrolled in the study. We've actually stopped the pre-screening, and so we filled our screening group of patients, and we're converting those into patients enrolled in the study, and we're looking forward to revealing top-line data in the middle of next year. Got it. Thanks for taking the questions. I'll also mention that we're taking that momentum and we're shifting it over to BLU-263. You know, the HARBOR trial has an even more extensive site list. We've discovered a lot more interest and really enthusiastic about this next generation KIT inhibitor moving into the treatment. Great. Thank you. Our next question comes from Dane Leone from Raymond James. Please proceed with your question. Hi. Thank you for taking the questions. I'll keep it to two for me. Firstly, could you comment at all in terms of the progress with the BLU-945 phase I enrollment and treatment? Anecdotal evidence that I think most of us have seen at this point does suggest you're getting a mix of patients that do and do not have a T790M mutation. I'd be curious about your thoughts around the complexion of the patients getting treated in that dose ascending study and kind of the implications for evaluation of the therapeutic index and what's gonna be effective for those patients with T790M. And then secondly for me, could you just maybe comment a little bit more in terms of the treatment center utilization around ASM now? For those treatment centers open, where do you think the percentage of docs and patients being treated now that would qualify for avapritinib are getting the drug? Just some of the hurdles that your team's trying to get over now to increase that utilization rate heading into 2022. Thank you. All right. Fouad, why don't you take the 945 study question, and Becker can add color as necessary. Thank you, Dane. For BLU-945 in the SYMPHONY trial, we are very happy with the way it is progressing in the dose escalation phase. We have, you know, four- months into phase I, we have seen really a good momentum. We are also very happy that our use by the investigator of tumor and ctDNA is able really to pick up on a variety of mutation, T790M mutation, C797S mutation, double mutation, and triple mutation. All this information, and with the profile of BLU-945, would allow us, you know, in the next months to have much better understanding of the safety profile and also be able to see detection of clinical signals. We will be sharing data next year on the first part of BLU-945. All right. Christy, why don't you take the breakdown of where we're seeing activity in ASM? Yeah. Yeah, I think your question sort of speaks to, I think what the opportunity is going forward in terms of, you know, additional opportunity at centers as well as beyond that. As I said, you know, we're pleased to see that we've had engagement and utilization by two-thirds of sort of the accounts that we consider to be, you know, key accounts and centers of excellence, which is great. I'm also very happy that we've got you know, a significant amount of utilization coming outside of those accounts, in the community. I think there is additional opportunity within key accounts. You know, I think what's interesting about ASM is that it is still an immature market in many ways. Unlike other diseases where you may have, you know, one specialist at a center that tends to have every patient funneled to that person, what we see in advanced ASM is that these patients at a center may be seen by multiple providers. One trend that I've been, you know, watching and interested to see is that we're starting to see more than one prescriber at a given account utilizing AYVAKIT. That deepening within accounts is something that, you know, we're gonna continue to focus on as we go forward. But long term, I think the key driver for us of, you know, additional patient identification and growth will be also really getting out into the community where we have that, you know, tail of patients that are presenting. Again, you know, really happy with what we're seeing. Certainly looking forward to, you know, having additional catalysts going forward as our data gets out and we continue to educate and identify more patients there. Thank you. Our next question comes from Marc Frahm from Cowen. Your line is now open. Hi. Thanks for taking my questions, and, congrats on the quarter. Hey, Christy, just to follow up on the last points about, physician use and who they are. When you are seeing use in the community, is that still just with community-based oncologists or are you seeing some use in other things, places like allergist's office and things like that may have broader populations than just ASM within their practice? To follow up on Dane's question on the different types of patients enrolling in 945, would you expect to ultimately have expansion cohorts that are broader than just C797S for some of these other resistance mutations, or is C797S really the main focus? Sure. I can start with your first question. In terms of the mix of prescriber types that we're seeing, the vast majority of utilization right now is coming from hematology, whether that's at a center of excellence or in the community. We have seen some utilization by allergy. I think what's important to keep in mind is that allergists play a role in the management of advanced ASM patients and certainly are a you know a critical point in the pathway to diagnosis for many of these patients and will often be involved in co-managing patients with hematologists. We've seen some utilization coming from allergy, but again, the vast majority coming from hematology at this point. For your second question, Mark, for 945 is our triple mutant agent, covers you know the drivers, but also T790M and C797S. The way the SYMPHONY phase I trial was designed is to expand in all subgroups of mutations. We'll be expanding in triple mutations. We'll be expanding also in C797S double mutation and in T790M double mutation. We'll have really a very good understanding across the broad spectrum of these combinations of mutations. I just wanted to add one thing. Marc, the 945 compound is optimized to hit the triple mutation, but it is a compound with a really large window to wild type, so we expect extraordinary safety. That really plays into our plan to combine these molecules and move to earlier lines of therapy. We're really open to all levels of activity for this compound, just given how safe we expect it to be. Okay, thanks. Very helpful. Our next question comes from Andrew Berens from SVB Leerink. Your line is now open. Thanks. Let me also add my congratulations on the AYVAKIT execution this quarter. Just a few for me. I'm trying to get a sense of how excited we should be about these results being sustainable. Were there a meaningful percentage of patients using AYVAKIT this quarter from the expanded access program? Do you guys have any color on how many lines of therapy they had seen previously on the average or how long the patients have been diagnosed? A question on GAVRETO for Christy. I didn't hear you give a percentage of new patient starts like in prior quarters. Just wanted to see if I had missed that. Again, wondering why the 40% you saw in Q2 and the 25% in Q1 doesn't seem to be translating to revenue. Is it really just the RET market is not that large? I think all of those are for me. Happy to start with the SM color. In terms of, you know, patient dynamics in the quarter, we did have some patients who were on access programs prior. It's the minority, certainly, of the patients that we saw, coming on to AYVAKIT through the quarter. I think your patient or your question sort of speaks a little bit to, you know, is this a bolus? And, you know, I think what we've seen certainly is that there were patients who, you know, were frankly waiting for AYVAKIT approval. There was a lot of excitement from the centers that, you know AYVAKIT well and have experience, waiting for the drug to become available commercially. Certainly, you know, we're pleased that we were able to pull those patients on and offer them treatment upon approval. What we now see and what I think will be sort of offsetting that and continuing to drive growth is the, you know, rate of new prescribers and accounts that continue to come on board. You know, I'm really excited about just the breadth, again, of prescribing. I see that as a critical indicator of long-term growth potential and, you know, pleased to see that we've continued to really add new prescribers and accounts at a very steady clip as we've moved through the quarter. In terms of lines of therapy, as I said, you know, our best data right now suggests that we're seeing a pretty even split in terms of patients who've been on a prior therapy versus those who say that they do not have indication of a prior therapy. Our visibility into that right now is limited, and as we start to see our own patients through claims data, we'll have a better sense, frankly, of you know, exactly what we think that mix looks like. I would say that we'll gain insight to that as we continue to move through the launch. In terms of GAVRETO, you know, the question about sort of how do we think about new starts and then, you know, kind of moving through to revenue. You know, with the transition to Genentech, our level of sort of individual patient visibility is simply different. They have a different distribution model than we do, and really we're looking at prescriber-level demand now as kind of the best indicator of growth and had our strongest quarter this year to date, essentially in Q3. We're excited about that. That, you know, speaks to, I think, the ongoing growth of the market, which we're seeing across both Blueprint and Lilly. It will take time, as I've said before, between, you know, new product, new patient starts sort of transitioning into revenue. You know, new share is a leading indicator of total share, which then will translate into revenue over time. Of course, you know, our quarter-on-quarter revenue growth continues to be really strong. Okay. Thank you. Our next question comes from Avatar Jones from Morgan Stanley. Your line is now open. Thank you for taking my question. Many have been answered, I have one question on AYVAKIT. Do you have any visibility into the average duration of therapy to date? And moving forward, how would you suspect this will evolve? Thank you. Sure. You know, duration of therapy is one of the aspects of you know, the AYVAKIT opportunity in advanced SM that I think is most exciting, and certainly will be a critical driver of growth, particularly as we get further into the launch and, you know, can see patients, you know, sort of accumulating because they can stay on therapy. I also think it's exciting because, you know, we have the potential, I think, to really impact you know, how long patients are living well with advanced SM, which I think is a really exciting clinical opportunity. At this point in the launch, it is just too early to really have any meaningful insight into duration of therapy, right? We're a couple of, you know, few months onto the market at this point. Certainly our clinical data suggests that patients may be on for years. You know, I think we'll have better insight as we go through over the next, you know, year or two to really understand what we're seeing in terms of what that looks like. Okay. Thank you. Our next question comes from Arlinda Lee from Canaccord. Your line is now open. Please proceed with your question. Hi, guys. Congratulations on the quarter and the launch. I had a maybe an additional follow-up on additional color that you might be able to provide on the breakdown of newly diagnosed patients versus those that were already known. If you can maybe talk a little bit about the turnaround time for the Labcorp tests and what kinds of you said that it would be available to patients that were eligible. Could you provide additional information on who might be eligible? Thanks. Sure. Again, in terms of the split of patients that we're seeing right now, we're really relying on the feedback we hear from patients and prescribers directly, which is how we understand that mix of, you know, about half saying they do not have prior therapy versus half, you know, saying coming from a variety of other therapies that are being used. No indication of prior therapy does not necessarily mean that they're newly diagnosed. We will, you know, continue to gain insight to that, as I said, as we start to, you know, kind of see claims data and other sources that will help inform our understanding. You know, our expectation certainly is that as we move through the launch, we will shift from being, you know, utilized primarily in prevalent patients who are already diagnosed to newly diagnosed incident patients. That's a dynamic I would anticipate we will see, but again, it's just too early to really know what we're seeing. In terms of the Labcorp test, the turnaround time is fairly quick. I believe it's something on the order of, you know, less than a week. And the eligibility criteria, essentially, we ask physicians to fill out a form where they have to specify one or two of a couple of different symptoms that are often hallmarks of a potential SM diagnosis. Essentially, what we're looking for is suspicion, clinical suspicion of SM, in order to be eligible for the test. Great. Thank you, and congratulations again. The next question comes from Michael Schmidt from Guggenheim. Your line is now open. Please go ahead. Hi, this is Paul on for Michael. Thanks for taking our question. Just one from us on the CDK2 program. Can you provide your thoughts on how BLU-222 potentially compares with other CDK2 approaches in development? For instance, molecular glues and triple inhibition of CDK 2, 4, and 6 are being explored. Just hoping to see your early read there on the landscape. Thanks. Fouad, why don't you start, and maybe Becker can add color if needed. Thank you. Our CDK2 inhibitor that is entering the clinic early next year, as I mentioned earlier, is a selective one. It has been developed as a validated target, a regulatory partner of CCNE1, with particular selectivity over CDK1, CDK4, CDK6, and others. This allows our CDK2 inhibitor to be selective, leading to efficacy and potentially in very favorable safety profile. When you look at the entire landscape, one of the challenges the landscape faces in developing CDK2 inhibitor is CDK selectivity over CDK1, but also over CDK6. We do believe that our CDK2, with its very selective profile, is also a very good partner for combination with CDK4/6s. We believe the strategy of developing a selective sole CDK2 inhibitor is a good strategy that gives us the ability to combine at different doses with CDK4/6s. Our development strategy targets two major areas, CCNE1-driven cancers, where we believe that tumors are addicted to the pathway, ovarian cancer, endometrial cancer, where CDK2 would be developed in combination with standard of care in their diseases. The other part of the development of CDK2 will focus on the emerging issue of resistance to CDK4/6 in breast cancer. We know today that CCNE1 overexpression is behind the resistance to CDK4/6 in breast cancer. We'll be looking to really contribute to reverse this resistance, not only in the late stage by combining CDK4/6 in breast cancer, but also in the early stage. Great. Thank you. Our next question comes from Joel Beatty from Baird. Your line is now open. Hello. This is Benjamin Trupp for Joel. Two questions for us, one on AYVAKIT and then one on the pipeline. As far as AYVAKIT, do you have a sense? I'm not sure if I missed it or not, but the number of repeat prescriptions? And then on the pipeline, I'm just curious if you could maybe put in the context of relative risk of the different plan initiations for BLU-701, BLU-222 and BLU-852. Do you see one as more highly risky or less risky than the others? Thank you. Sure. This is Christy, I can take them. The first one on repeat prescriptions. Again, we're you know early on in the launch, we've seen nothing that would be any different than what we would expect, which is in terms of, you know, we expect patients will be refilling. Certainly, we do know that often if patients are gonna find their right dose, that is a dynamic that happens early on. Dose modifications, et cetera, tend to be occurring in the first few months. Our strategy around flat pricing, et cetera, you know, really mitigates a lot of the impact that we would expect to see from that. That's you know a trend we'll continue to watch. So far, we're seeing you know everything essentially in line with what we would expect. Sure. In terms of the relative risk, maybe, Fouad, I'll have you start, but, you know, I think it's a question we look at all of our programs in terms of going after known oncogenic drivers of disease, where there should be a higher probability of success or in cases where we can get to clinical proof of concept as quickly as possible, remains a hallmark of our portfolio selection priority or our process. We do always take into account as well, though, the size of the opportunity or the relative opportunity. Right before you enter the clinic, it's almost an impossible exercise, but Fouad, why don't you take a stab? The only thing I would add, Jeff, to your answer is Blueprint as a leading precision medicine company has really, you know, one of the strongest expertise in rationally designing molecules that are selective against targets that we would like to use as treatment. To Jeff's point, these targets are well-validated and are important for the treatment of cancer. It's now taken Blueprint to a next level of targets with a broader scope of the opportunity, whether you think about it from EGFR mutated lung cancer or breast cancer resistant to CDK4/6 as an example for CDK2. Obviously, these studies are either in phase I or entering the phase I clinical trials in the next weeks or months. So we would have more information to determine really the profile of these agents. I think with responder hypothesis as a part of the development, with selectivity, with windows of therapeutic indexes in the development of this compound. I'm confident that we will run these compounds very efficiently, and the data will tell us what when we see it from the phase I. Yeah. Maybe I'll circle back. It's interesting, Kate Haviland, our Chief Operating Officer, often talks about the idea that how do we get better with subsequent programs over our first wave of programs? It has always been a cornerstone of our strategy to develop molecules that can be combined with other effective therapies if we really wanna change the course of disease. As Becker noted earlier on BLU-945, that was part of the target product profile, that to reach the full potential was to focus on that, the window over wild type so that you could see various combinations expanding the opportunity over time. Similarly, I'd say, you know, that's true for BLU-222, our CDK2 program, that we will certainly be looking for single agent activity, but the true opportunity comes in how do you combine over time. That selectivity that Fouad talked about with respect to BLU-222 is really critical to what we hope to see as we move into the clinic. Got it. Thank you so much for those insights. The next question comes from Peter Lawson from Barclays. Your line is now open. Great. Thanks. Thanks so much for taking the question. Just kind of thinking about the GIST and the ASM revenues underlying this, is there any point where you break out those revenues and/or would you kind of break out when GIST, or rather ASM kind of exceeds the GIST revenues? Just your thoughts there and if that happened this quarter. A second question for Mike, just on a breakout of the guidance. You know, how much is that milestone driven? Should we think about that milestone number as a $75 million or a $50 million number? Thank you. Maybe I'll start. We don't have perfect visibility into every patient, so the effort of trying to break out exactly where each of them sits will probably be difficult. I don't think it'll be a focus. I mean, based on the data we see, that as Christy has already highlighted, the growth is clearly coming from ASM. Exactly where that line is, I don't think we have that degree of detail. Maybe, Mike, you... Yeah. Just a little bit more color on the revenue guidance. I think maybe backtracking a little bit, like early in the year, we guided to the fact that we might have $80 million in potential milestone payments. What we've seen, we've recognized a little bit of that today, but what we've seen is primarily a lot of potential milestones are now concentrating in Q4, and that also includes the acceleration of potential milestones that were originally, I'd say, forecast for 2022. As those come together and come to fruition in Q4, the bulk of the revenue guidance raise that we're seeing is driven by milestone revenue that we anticipate, as well as other collaboration payments, supply payments, and royalty payments. Yeah. Maybe I'll add to that. I mean, that's. I think that's an overall underappreciated aspect of our current position, is that, you know, we've always focused on retaining meaningful commercial rights and bringing therapies to patients on our own. We also have looked at collaborations as an opportunity to either accelerate or expand our reach. The breadth of collaborations we now have in place is truly differentiating our revenue streams. That, you know, what is in exactly quarter-over-quarter may be a little bit lumpier than revenue growth or end-user revenue growth. We're seeing a mix of milestone payments, royalties, and other payments from partners that is gonna continue on as we go forward. You know, I would say as in my seat, it. I don't really care where the revenue comes from. It's meaningful, and it allows us to continue to invest in our research platform, which is the way we're gonna drive long-term shareholder value. Gotcha. Thanks so much. Just to follow up on Christy's comments about ASM. Are the majority of patients gonna come from the heme or the allergy side for ASM eventually? Yeah. Advanced ASM certainly will be majority hematologists. That, you know, that's the specialty that tends to primarily manage. As I said, allergy certainly can be involved. Sometimes they're involved in co-management, but we expect hematology to continue to be the primary driver for advanced ASM. Brilliant. Okay, thanks so much. Our next question comes from David Nierengarten from Wedbush. Your line is now open. Hey, thanks for taking the question. I'll skip any commercial questions. They've often been beaten to death. On the pipeline for 701 and 945, maybe if you could help us out with the ultimate goal. Is it to have a combination therapy with 701 and 945 in that setting and, you know, say second- line, you know, EGFR mutated lung cancer. You know, and then what, you know, if that's the ultimate goal, what do we need to see from the single agent studies to, you know, accelerate your entry into the clinic with a combo? Thanks. Thank you, David. 945 and 701, our fourth-gen EGFR, a fourth-generation EGFR agent, have been developed with combination in mind and have been designed with combination in mind. Very quickly, 945, as Becker mentioned earlier, has one of the widest selectivity profiles over wild-type EGFR. That allows this compound not only to be developed as a single agent, but also to be developed in combination with other agents. As I mentioned earlier, we'll be starting next year combination with third-generation EGFRs and 945. 701 has also been developed as a single agent, highly potent on C797S mutation, on driver mutation, more importantly, highly brain-penetrant, but also developed towards combinations with other agents. For the on-target combination strategy, we would like to see each agent develop as a single and in combination in the late stage. Our ultimate goal is to move these two agents together to the front line treatment of EGFR-positive non-small cell lung cancer. That's because of the profile of both agents, the potential synergy and combinability in terms of being able to displace and do better than standard of care. We will also be looking, in addition to the combination of 701 when it's ready and 945, to combination with other agents. I talked about third-generation EGFR such as osimertinib, but we will also be looking at combination with off-target agents, just given the profile and the selectivity of these compounds. Off-target agents can include a variety of things. Could be MET inhibitor, could be RAS, could be chemotherapy, and others. I do believe that these fourth-generation agents developed together could become transformational in the treatment of EGFR-mutant non-small cell lung cancer. Thanks. Maybe just a quick follow-up on the, you know, other potentially off-target agents. You know, again, you know, I guess I'm curious, you know, how far you might look into those before, you know, again, focusing on a 945, 701, or is it going to be, you know, just a broader basket study and open to, you know, just interpreting the results as they come? Thanks. Sure. This is Becker. I'll take that. With respect to combining with agents that have other mechanisms of action and address resistance or potential resistance from other targets, such as MET or RAS inhibitors. Initially, we need to get the tolerability and dosing information for our single agents, but I don't see it as a sequential development. We tend to do these things in parallel. We're quickly adding combinations to our ongoing studies and we'll let the preclinical data guide us to an extent, but emerging data on resistance and trying to get in front of resistance is really where we're going with this program in a broad fashion. Got it. Thanks. Our final question for today comes from Brad Canino from Stifel. Your line is now open. Great. Thanks for fitting me in and great launch execution here. I mean, just one more from me on the EGFR trial. Again, specifically on that cohort that's T790M, but not C797S. It looks like per the protocol, they're gonna go first-gen to osimertinib to BLU-945. Like we talked about previously on the call, likely cancer there is driven by something other than T790M, like MET. Are you expecting to see, and should we be looking for monotherapy BLU-945 efficacy in this specific cohort because you've been talking about the higher therapeutic window and wild-type sparing, or is this really the focused safety on this cohort? Thanks. This is Becker. I mean, obviously in phase I safety, it's the initial focus and the main focus of this study. However, just a reminder, BLU-945 will inhibit very strongly any protein that has the T790M mutation on it. We are trying to understand better the heterogeneity of this cancer. There are patients where we believe that the EGFR mutations or the EGFR protein is still the primary driver, and the more we look, the more patients that seems to be the case. There are other patients where it's more heterogeneous, and you have multiple populations of cells or even multiple drivers within a single cell. As we understand the biology, we'll have a better sense of where to expect single agent activity. That's an emerging story that we'll speak to later when we have more data. All right. Thank you, Brad. I'll hand the call back to Mr. Albers for closing remarks. Thank you, operator, and thanks to all of you for taking time to join us today and for your continued support of Blueprint Medicines. We look forward to updating you again soon and hope you all stay well. Goodbye. Ladies and gentlemen, this concludes today's call. Thank you for joining. You may now disconnect your lines.