Ladies and gentlemen, thank you for standing by. And welcome to the Blueprint Medicines Conference Call. At this time, all participants are in a listen-only mode. After the speakers’ presentation, there will be a question-and-answer session. And I would now like to hand the conference over to your speaker today, Kristin Hodous of Blueprint Medicines.

Thank you, and please go ahead, ma'am..

Thank you, Operator. Good morning, everyone. This is Kristin Hodous of Blueprint Medicines. And welcome to Blueprint Medicines first quarter 2020 financial and operating results conference call..

Thanks, Kristen, and good morning everyone. Stuff like acknowledging the challenges we're all facing as a result of the evolving COVID-19 pandemic. At Blueprint Medicines, we're doing everything we can to protect the health and well-being of employees, patients, and providers. Well, we also seek to maintain continuity across our business.

At our core Blueprint Medicine is driven by a culture of urgency, and our team has always been agile and resilient when faced with challenges. As we've dealt with this situation, I've been proud of our employees who have stayed focused on the needs of patients, embrace new ways of working with purpose and good humor, and continue to deliver on goals.

This is evident by the sustained productivity across our portfolio in the first four months of the year. Nevertheless, the pandemic is having a range of global impacts that create uncertainties for our business.

For example, some sites participating in our clinical trials have experienced temporary disruptions and social distancing restrictions certainly make externally facing activities more difficult. So, far, we've worked effectively to address these issues with tailored solutions.

We provided individualized support and accommodations for impact at trial sites and we've expanded our use of technology to engage healthcare providers and other stakeholders..

Thanks, Jeff. Good morning, everyone. Today, I'm pleased to provide an update on the commercial launch of AYVAKIT, as we report product revenues for the first time. In the first partial quarter of launch, we achieved net sales of $3.5 million.

More importantly, we've made progress against our goal of establishing Blueprint Medicines, as the leader in precision medicine with oncology and hematology centers of excellence. With an experienced and nimble team in place and executing well, we are building a solid foundation for the multiple launches we anticipate in the coming years.

Since our approval in January, we focused on educating prescribers to ensure positive first experiences with AYVAKIT. And I've been incredibly encouraged by the early breaths and prescribing that we've seen. So far, we've had more than 100 unique prescribers of AYVAKIT, and approximately 40% of them practice in a community setting.

We're pleased with this initial uptake, which highlights increasing awareness of an AYVAKIT among healthcare providers, even as our ability to engage in person has recently been impacted by social distancing restrictions..

Thanks, Christy. Earlier this morning, we reported detailed first quarter 2020 financial results in our press release. For today's call, I'll touch on a few financial highlights from the quarter. We ended the first quarter with $750 million in cash as compared to $548 million as of December 31, 2019.

This increase reflects net proceeds of approximately $308 million received from our public stock offering in January of 2020, partially offset by cash used in operations..

Your first question comes from Salveen Richter from Goldman Sachs..

Thanks for taking the question. This is Andrea on for Salveen.

Maybe a question for Christy, what have been the key drivers for the rapid uptake that you've seen for AYVAKIT here? And how should we think about the launch trajectory on the forward? And maybe if you could comment on whether there's been a bolus of patience or any inventory stopping in the first quarter? Thanks so much..

Sure. So, as I think about the uptake over the first quarter, we were clearly pleased there to see that that rapid uptake, I think it speaks to the unmet need and just to be frank, these patients have not had good effective therapy really be on the first line, and certainly, PDGFRA alpha patients, as we know, have not had any effective therapy.

And the community I think, has been very aware of that need and so the availability of a new therapy to address those patient needs I think has been incredibly well received.

I think it also speaks to the, the experience of the team that we brought on board, many of whom have relationships, particularly with a community oncologist and with key centers, and we're able to rapidly get access to those centers to help drive education.

As I think about, going forward, the unmet need and just as high and so I don't expect that to change. It's difficult to speculate how the trajectory may evolve from here, we're dealing with a partial quarter of launch.

Obviously, there's other macro factors around COVID, et cetera, that could impact how things move forward from here, but I think it really speaks to, again, the unmet need, and GIST which, which remains..

Great. And then maybe just a follow-up on that about the bolus of patients or how these maybe - where these patients were coming from us. They're all new patients that were just recently identified..

Yes, sure. So, we had a small number of patients who were on compassionate use prior to launch, that were able to transition over. But it was small relative to the number of patients who were prescribed through the first quarter.

And in fact, one of the things that I was very pleased to see, starting really out of the gate is that we saw prescribing breaths that went, beyond centers that were either participants in our clinical studies, or where somebody had prior experience through compassionate use.

So, we're seeing a significant amount of demand coming from new prescribers who have not had prior experience and who are identifying patients through the work of our team has been engaging and educating. And you also asked a question about inventory, which I didn't address, apologies. That really was not a significant factor, either.

This is still a small patient population and we're managing primarily through a network of specialty pharmacies and so inventory is not good. It'd be a huge factor as we think about the quarter..

Great, thanks so much..

Your next question comes from Dane Leone from Raymond James..

Hi. Thank you for taking the questions, and insight on the updates for the upcoming milestones. I just, I wanted to touch on one thing that you mentioned around building up a network for testing and patient identification for all of your programs, but you also highlighted systemic mastocytosis as well. A number of labs do the testing.

I'm not sure how standardized is it, but can you just explain on that is the idea here as you go through and develop is into a commercial launch and SM into a latter part of the clinical study that you want to have standardized testing for the D816V mutation specifically.

And that, in your view, would be something that would be specific to the label of the drug ultimately? Then I have one follow-up..

Sure. So, that the overall goal with systemic mastocytosis is to facilitate patient identification and shorten the time of diagnosis, which we know right now can take years for many patients. And as you said, KIT D816V testing is really key to that, that is the driver for these patients and so what we're doing, I would say is twofold.

One is just trying to work to build up capacity around highly sensitive KIT D816V testing, that is something that, we want to make sure is available and accessible to healthcare providers.

And, labs vary right now, in terms of sensitivity of the tests that they offer, particularly if you think about blood-based KIT D816V, which I think could be something that could really help facilitate patient identification, you really need a sensitive assay. And so, we're working on helping to stand up that that capacity and capability.

The other piece around this is thinking about algorithms that can help patient identification. So, to give an example, elevated trip taste is something that, often can be used to flag these patients, it would be great to have that then trigger further testing.

And so, working with labs to kind of help put in place some of those algorithms so that we can help the community walk down the path to identify those patients. We are not at this point anticipating that our labelling would require KIT D816V testing..

Okay, and then just one follow up on the upcoming data set for RET at ASCO.

Is it fair to say that we'll be getting what would be considered the primary analysis that essentially reviewed response rates at ASCO, basically what would probably reflect what we would see on the FDA label for both lung and thyroid?.

Sure, Dane, this is Jeff. I'll take that and Andy could add color if necessary. So, I think you set it up correctly that we as disclose the top line data for pralsetinib and non-small cell lung cancer filing earlier this year, this presentation would be a more detailed look at that data.

And if you think back to what we did last year with PDGFRalpha driven GIST, it's very similar. We announced the top line data, we pulled back together for the regulatory filing.

And then at a subsequent medical conference, we dug into the data and talk more about the response rates, durability of response safety profile, with greater detail, so it'll be a similar path to what you saw at that time..

Okay, thank you..

Your next question comes from Joseph Thome from Cowen and Company..

Thank you for taking my questions. The first one on the initial AYVAKIT and again in the prepared remarks, it was mentioned that the confirm coverage is at or better than the approved label.

Can you just dive a little bit more into what the or better could mean for some of the coverage decisions and has everyone that's been treated so far had a confirm PDGFRA mutation if you're able to get that information? And then on the second point, given, we know that there's COVID related dynamics, but do you still anticipate that part two or PIONEER will complete enrollment by the end of the year, this year sometime around then? Thank you..

Yes, this is Jeff, now dealing different locations. So, we couldn't hear. I'll take that question in reverse order. I will do the first part and then I'll hand it over to Christy, to answer the first part of your question.

So, the second part, when to timelines going forward, and you alluded to COVID-19 pandemic and where we sit now is as a reminder, the indoor systemic mastocytosis was a two-part study. So, part one, we share data on March and then based on that data inform the design, size, dose etcetera for part two. So, it's the same study.

So, this isn't something that we have to initiate a new trial per se. And in some ways, we were fortunate in that the second quarter was a time where we were collecting all that data working with our investigators to set up part two. So, really plan to have that be a study that would be accelerating enrollment in the second half of this year.

So, where we sit today is, is we're still on track for that plan to begin screening and we're working with investigators now on part two, precisely when the first patient will be screened or dose is obviously more difficult given the COVID-19 pandemic and a lot of it depends on, where that first patient would be from a global perspective and a site specific perspective.

But we're increasingly optimistic we're seeing some signs of things opening back up and as I talked about, in the opening remarks, there is no doubt uncertainty about exactly how it will roll out, when you add a pandemic on top of general clinical trial execution, but we have no reason to change the guidance at this point that that, we're continuing to plan to begin screening this quarter and really start enrolling in earnest in the second half of the year.

And, Christy, the first part..

Sure.

So, to the question around coverage and what we're seeing in terms of our patient mix over the first quarter, as I think about what it means to cover at or better than label clearly what we want to see is that payers are covering patients with no more restrictive criteria, Certainly than our current label, which is PDGFRalpha exon 18 mutant GIST and that is that is what we're seeing, we're certainly not seeing anything around, step edits or additional prior authorization criteria that would be more onerous than that.

As I mentioned, I think on earlier calls, GIST is a small indication with very high unmet need. We also see NCCN guidelines that specify not only AYVAKIT but other therapies that are used in GIST that may not be indicated.

So, certainly some payers are going to take a broader approach in terms of how they, they cover, not only AVA but other therapies, and we're certainly seeing that in reality. I think your question, getting to kind of what do we see around mix of patients, and we're certainly seeing strong utilization among PDGFRalpha patients.

But I think an important point for everybody to remember is that it is just not possible with precision to be able to clearly pull apart patients in GIST, we are promoting this drug clearly for PDGFRalpha patients, that's the indication.

But ICD 10 codes don't allow you necessarily to figure out what the mutational status is of every patient and so we have some insight certainly through our field and through other means in terms of what some of these patients look like and certainly see a healthy utilization among PDGFRalpha but also indication that we're seeing utilization outside of there as well.

That's not being driven by us but that is organic coming from the community due to the high unmet need and KIT driven GIST..

Great. That's very helpful. Thank you..

Your next question comes from Konstantinos Aprilakis from Deutsche Bank..

Good morning guys. Thanks for taking my questions.

I just got a few on pralsetinib and perhaps for Andy so for the upcoming update at ASCO, how much additional follow up can we expect from the last time we saw data in lung cancer back in January and thyroid in April? And should we expect mature response durability data in lung cancer, either in the abstract once it's released or the actual presentation?.

Yes, this is Andy. And so of course, at this point, just the titles have come out for ASCO, we're going to be giving I think, as Jeff already started to speak to an update across the study. As you can see from the titles one focuses on the lung cancer, fusion lung, the RET fusion lung cancer data, the other is abroad or across other RET fusion tumors.

And we certainly have more follow-up since we've presented the top line data back in January and we'll give an update with additional follow up compared to what we've presented before. But I think at this point, we should just wait for the abstract to be coming out..

Thanks..

Your next question comes from Reni Benjamin from JMP Securities..

Hey, good morning guys. Thanks for taking the questions and congratulations on the initial launch. Maybe just a question regarding pralsetinib and and NTC said you're on track to submit the NDA for the FDA. I'm kind of curious as to your thoughts regarding the European filing.

Should we be assuming a concomitant European filing as well? And I don't remember if you've talked about this in the past, but what are your plans regarding sales force and go to alone strategy in Europe versus potential partnering?.

Sure. And this is Jeff, I'll take that and again, I'll open up to Andy or Christy if they want to add any color. For our European filing, our plan is very similar to what we've done in other instances where first we filed in the U.S. and then shift our focus to European filing for pralsetinib.

In terms of go alone strategy, we have already initiated a build in Europe. We've got a team on the ground and as we looked at the diversity of our portfolio and the strength of our research pipeline, felt like that was the right move.

We've got a file already in for PDGFRalpha driven GIST and as we disclosed today, we've now filed for non-small cell lung cancer. So, we think we'll have a similarly robust offering, as you look at those two potential indications and then similarly add systemic mastocytosis. So, both in the U.S.

and in Europe, we plan to bring these medicines directly to patients..

Got it.

And then I guess just as a follow-up regarding the right size of sales force, just kind of given your thoughts regarding GIST, has there been any changes or what are your latest thoughts in terms of the size of the sales force and the commercialization strategies?.

Sure. So, I'll start this, but I'll turn it over to Christy quickly. Really, we talked about this a bit last week, that there's in fact no change to our plans.

And Christy hit on some of this in the opening remarks as well, is that, our priorities as we've articulated really beginning at the R&D day last year have been around pralsetinib for multiple indications and avapritinib beginning with systemic mastocytosis.

And as we built out the commercial team really focused on those two areas with GIST being a more modest focus. And so, I don't think that changes, but maybe I'll hand it over to Christy who can talk about that in a bit more detail..

Yeah, thanks. So, agreed. We, as I thought about the build here, I feel like we were very fortunate to have AYVAKIT and then pralsetinib launching and very close proximity and so really thought about the commercial structure with a portfolio view. And in fact, if we have been launching AYVAKIT and GIST, I wouldn't have built the team in this way.

And so, it was very much focused on having pralsetinib come behind it. We hired for that experience.

We've been clear from with our team from day one when they walked in that we were really looking towards pralsetinib and that ultimately that would be the priority because that as we think about our corporate priorities, SM and PRO have really been where we're focused longer term. And so, our team has been actively engaged there.

We saw some natural overlap between long and GIST targets, and we've been able to take advantage of that already. But our team has started the pivot towards lung, which had been planned all along. And so, while I'm certainly disappointed about the voyage or outcome, it really doesn't impact how I think about how we move forward from here..

Perfect. Thanks for taking the questions..

Your next question comes from Michael Schmidt from Guggenheim Securities..

Hey guys, this is Charles Xuan from Michael Schmidt. Thanks for taking the questions and congrats on all the progress. First one as a follow-up on some of the previous questions that have been asked. I’m kind of wondering, given you guys have highlighted some of your patient's assistant programs.

How should we think about percent free drug supply, gross net pricing adjustments? And also, similar - another question along the launch trajectory is how should we think about patient stocking as opposed to inventory channel install can give potential of COVID social distancing measures? Thanks..

Sure. So, I will try to address those, although patient stocking is a new one, so I may have to ask you to clarify that one.

But in terms of gross to net and free drug, our gross to net, as we said is coming in line with sort of where we expected, which was around 85% mid-teens, that of course, can fluctuate over the course of a lunch as everyone understands as you grow revenue, some other things that impact gross to net our percent sales, others are absolute fixed costs.

And so, we will keep an eye on that as we go forward. I spoke a bit about free drug at our launch call back in January. And at that point, said that we expected our pap utilization to be significant. We made a strategic choice to provide support to patients. That's our focus and priority, and that includes Medicare patients.

And as I know, this group is all very well aware. That's a challenging patient population in terms of options to really manage out-of-pocket costs. And so, our experience has sort of been in line with that, we've seen significant pap utilization, but it's fluctuated through the quarter.

And so, I think it's a little premature to speculate on where exactly, it's going to land, I think we'll be able to give more color on that as we go forward. When you're dealing with a small base and you're dealing with kind of payers coming online, et cetera. It can move up and down quite a bit and I've seen that over the first quarter.

So, we'll keep an eye on it going forward and after we'll be looking at things like for example COVID, and how the economic impact of that may impact our pap utilization as well.

Your last question around patient stocking, I think were you asking around bolus or maybe if you want to just clarify what your question is there? And I can try to address that..

Yes, sure. I guess, especially with respect to some of these orally self-administered medications, like - is there a potential ability, for example, for patients to obtain more than I guess, the "usual amount of drugs at one time.".

Yes. No. Thank you for the question. So certainly, I think at a macro level, if you look at trends across multiple therapeutic categories, I know that there has been some push towards, for example, 90-day sales. That is not something we've seen in a significant way.

In GIST, I think these patients are sick enough where certainly there's a desire to keep in contact with them, they tend to be managed pretty closely. And so, we have not seen big changes in terms of how patients are being dispensed therapy..

Makes sense. And just switching gears a little bit over to advanced SM.

Maybe this one's for Andy Boral, how should we think about potential differences in AYVAKIT treatment duration and advanced SM patients between those with purely mass cell driven diseases versus those with an associated hematologic malignancy? And as a related follow-up, what would it be a fair characterization that the age and portion likely contribute more towards patient mortality given AYVAKIT potency against purely mass cell driven diseases and apparent survival and mass cell leukemia with the caveat of course, that patient number reported patient numbers have been small so far..

Yes. It's Andy, no. I mean, I think the potential differences in activity of across the difference sub types of advanced systemic mastocytosis. Certainly, something we've looked at we've brought up, we've pointed to early data in some of our presentation.

I think what we've been really thrilled to see with avapritinib, it's just the broad consistent activity across advanced systemic mastocytosis in terms of both response rate and durability really irrespective of subtype, pure ASM, ASM within CT neoplasm and mass cell leukemia.

Now of course, we continue to follow patients from the EXPLORER and PATHFINDER studies for progression free survival and overall survival and those data will mature over time. But at - currently we're seeing very durable activity across the board.

In theory, you might expect the AHN patients to have progression of their AHN, but I think in many of these pay transactions is dominant problem is still mastocytosis..

Maybe I'll just add to that because I think it's a really important question and it ties in closely to the consistency with which we put forward that systemic mastocytosis and pralsetinib in both lung imaginary thyroid cancer, as well as PDGFRalpha and GIST have been priorities because in each of those cases, you really have a monogenic driver.

And what that is translated into in the data that we've presented to-date are really durable responses. And I think that's an important point when you have a clear driver. And as you think about, how long could the patient stay on? We've got patients in our systemic mastocytosis trials out three, three and a half years at this point.

And then that is really a transformative, provides a potential transformative impact for those patients. And that's probably even more clear when you think about the potential in indolent systemic mastocytosis. Obviously, we're in earlier days there.

But that is why we were so pleased with the early data in the ISN patient population that we shared in the first quarter of this year at a low dose of 25 milligrams once per day, seeing real true impact across all the parameters of clinical efficacy that that you often think about for chronic treatments.

And you that's why then you tie that back to Christy's comments about patient identification, becoming so important. If you have these clear drivers, you want to identify the patients. And then the focus is on maintaining that durability of activity to really change the lives of the patients for the patients..

Understood, thanks for that answer. And thanks for all that detail..

Your next question comes from Eun Yang from Jefferies..

Thank you. I have a question on pralsetinib.

So, in terms of patient identification to drive a commercial success, can you discuss what percent of the eligible non-small cell lung cancer patients are currently seen in the academic versus community settings? And how long do you think it would take to fully implement the diagnostic testing in the community setting from the launch? I have a follow up question.

Thanks..

Sure, this is Christy. So, what we see with lung cancer, certainly the majority of patient volume would be in the community and that's true generally. I think, as you look at some of the larger oncology indications. Testing ramp I think is going to be very much driven by the availability of effective therapy.

So, we've seen this if you look at other analogous, sort of precision medicine trajectories around ALK or RAF1, you see a very quick ramp with the availability of a treatment that will drive testing.

We have been out actively promoting RET testing and really helping to educate around that through our precision medicine team as well as through our disease education efforts. And of course, we won't be the only ones driving that which I think is actually a very healthy and good thing.

So, I would anticipate that with the availability of effective treatment, we would see that ramp relatively quickly and probably faster than what we see in for other precision therapy launches for example, ALK..

Thank you. And then follow quick follow question. I understand that.

PFS is not required for approval of a pralsetinib in non-small cell lung cancer but your competitor has reported PFS data? So, at ASCO are you also presenting PFS data in addition to response and duration of response data?.

Hi Eun, I'll take that. So, yes. So, we first of all just back up. We have been thrilled with the evolution of the pralsetinib data in lung cancer and across the board thyroid cancer as well. And we'll be showing it at ASCO for the first time the other RET fusion tumors in a kind of comprehensive way in the other presentation.

So certainly, from a regulatory perspective for us or any other compound. Single arm study approvals based on single arm studies are driven by response rate and duration of response, not progression free survival. Certainly though, we will be pulling together. It's much more data than that for the presentation.

But again, as I said earlier, I'd really rather as we're getting very close to ASCO I don't - I'd really rather not comment on what we will have in the abstract and presentation and even that still being finalize now..

Thank you..

Your next question comes from Chris Raymond from Piper Sandler..

Good morning. This is Nicole on for Chris. Thank you for taking the questions. I guess first just on inclusion and RTOR programs for pralsetinib and avapritinib NTC, for the two new molecular entities approved do you think this pathway. We have seen a pretty quick review in approval process.

So, I guess just in light of this how are you thinking about the competitive setup release avapritinib given that the PDUFA date. Is that drug is expected in Q3.

And then I guess maybe second, just for the advanced are some update in the third quarter, could you be more descriptive about what we'll see for the top line data from EXPLORER and PATHFINDER trials? Thanks..

Hi, it's Andy. I'll start up on this. So, in terms of RTOR, the RTOR that we've talked about is regarding the medullary thyroid cancer submissions. We've already submitted the lung and I can say that certainly as with any submission, we have regular interactions with the FDA following the submission, we think that's moving along well.

But of course, timing is something that we'll understand better as the review moves along. In terms of RTOR for NTC, we see that as a great opportunity.

Of course, the whole concept is that we that under RTOR sponsors can submit data sets ahead of the first written documents and so that allows the FDA to start looking at the materials sooner than they otherwise could.

And certainly there, the FDA's goal with that program is to expedite the review of programs for products that they think bring particularly - potentially the highest benefit for patients. So, we would hope that that will move things along quickly. But of course, we can't really speak to specific timing yet.

And that initiation of that filing is on track for this quarter, as Jeff mentioned. The advanced SM update, so that'll be abroad. The update that we're planning will broadly update across the EXPLORER and PATHFINDER data in terms of what will be the top line data for the registration for the submission this year.

Beyond that, I can't really comment too much on what will be in there, but of course we'll be talking about response rate the IWG activity, we'll update on durability. I think it'd be the broad, general information that we would include safety..

This is Christy. Maybe I'll just chime in just to add a bit on the competitive aspect of your question regarding pralsetinib. If I just kind of take a very, a big step back, I think the picture here has really evolved very significantly over the course of the last five to six months the event.

I think we're now in a place where, if I start with just the data sets that have come out.

I think the clinical differentiation that we're starting to see in terms of our rate of complete responses, which we're hearing from KOLs is something that they find incredibly compelling, it could be differentiating as well as the thyroid data set, I think is, is really starting to evolve the picture of how people are thinking about the landscape here with these two assets.

And, I think RTOR and some of the other initiatives and what were the speed, I guess an urgency that we're hearing from the FDA, I think speaks to the desire to make this therapy available to patients quickly.

So, while there may still be some time lag between the approval of saracatinib and pralsetinib, I don't anticipate that it would be significant. And I think, particularly in a therapy area like this with RET where you're dealing with a relatively rarer mutation.

I don't think that the difference in terms of approval timing is going to end up being all that material as we think forward on the trajectory of these two products..

Thank you. Very helpful..

Your next question comes from Peter Lawson, from Barclays..

Hey, thanks for taking my question. Just maybe on the initial launch, if you can provide any more color around the line of therapy whether the drugs used in non-PDGFRA patients, any kind of details you can provide around the kind of patients taking the drug would be much appreciated..

Sure.

So, as I alluded to earlier, we've been very pleased to see that the breadth of prescribing and the uptake broadly, in GIST, I think it speaks to the unmet need and PDGFRalpha GIST, but also in GIST more broadly, our focus, our educational focus has really been on obviously PDGFRalpha and GIST that's the indication, and that's certainly where our team has been focused on identifying patients and driving testing.

And as I said earlier, we're certainly seeing healthy utilization there. But we don't have, visibility at a level of precision in terms of the exact breakdown of whether somebody has a PDGFRalpha mutation or they do not, the ICD 10 code, as I said is the same. That information is often kind of buried in the clinical history of a patient.

It's not straightforward to sort of pull that out from available data.

So, we very much rely on the intelligence that we're hearing from our field and our discussions with KOLs and based on that, I would say that, while we're seeing healthy utilization in PDGFRalpha patients, we're also seeing utilization as I said, outside of that line of therapy is even more complicated to tease out.

So, we know that again, when you get beyond first line, just the use of imatinib, it starts to become challenging, and patients tend to move through those treatments relatively quickly.

So, when we're outside of PDGFRalpha, I think you're probably seeing a mix of laser line KIT driven in just patients, but again we just do not have perfect insight into that..

Thank you.

And then maybe, if you could talk about potential pricing and how we should think about it in systemic mastocytosis, given the relief, kind of encouraging long durations, you'll see?.

Sure, so I can start and Jeff, if you want to add you absolutely can. We are - I'm not going to speculate on a pricing strategy at this point it's a little premature, but I started again from thinking about value just as we did with PDGFRalpha driven GIST.

With avapritinib, we have a therapy that is really the only therapy to show really profound activity on KIT D816V.

We have a therapy, therapeutic area in systemic mastocytosis where there are significant morbidity and mortality in that patient population whether it's advanced SM with, a shortened life expectancy across the board, or even an indolent form, where you are seeing patients hospitalized multiple times a year, threat of anaphylaxis, et cetera.

So, we'll be thinking about those factors. We also have obviously a benchmark approved therapy in advanced systemic mastocytosis in write up and our launch prices avapritinib was nearly 15% below actually that price.

And I would argue that, the value that we could be delivering to patients in the healthcare system with avapritinib will be significantly higher than write ups and so we'll be thinking about all of those things as we go forward.

And of course, the most important thing from a Blueprint perspective is to really prioritize patient access and make sure that, our pricing strategy enables our patients to gain access to the drug and to stay on it..

Great, thanks so much. Thanks to take the questions..

You have a follow up question from Dane Leone from Raymond James..

Hi. Thank you. Just I had two quick questions that came in from some other people. Did, Jeff, can you just give us a qualification of where you're thinking about potential partnering on the RET program? I know I asked you this all the time, but I think there were some comments earlier in the Q&A that might have confused some people so.

Can you just clarify where what you're currently thinking about whether you would partner program in the US or X-US or not partner at all? Thank you..

Sure. So, I'm not sure about which piece was confusing, but I think it's a direct enough question that I'll just take it. From a high-level perspective, so partnering strategy for us has never really varied that, our goal is to bring these medicines directly to patients that we think that's the way to drive long term value.

But that there were also constantly evaluating partnering opportunities and our bars is high there that if we believe a partner can either accelerate or expand our reach, whether it'd be a geographic reach, or that'd be to identify more patients is conducting a wider array of clinical trials et cetera. We'll evaluate that.

But we are certainly planning to bring these therapies forward on our own.

And, the deals that could be interesting might may range from something that's geographically based or something that's earlier research based, something akin to what we did with Roche previously in the field of cancer immunotherapy, or just something that that's incredibly compelling for all those reasons..

Okay, great. And then the one follows up is I was just asking on any timeline update for BLU-945 or the double mutant research program.

I think people have been just kind of asking if you have any incremental thoughts on when those could - clinic or get through an IND?.

So, this is Jeff. I'll take that one as well. As we started laying out at R&D day last year. We continue to be very enthusiastic about a range of preclinical programs that we have ongoing. And I think about the legs of the stool that will drive long term value.

It's systemic mastocytosis with avapritinib, it's pralsetinib across lung, MTC and other solid tumors. And then it's the additional programs moving forward, whether it be to BLU-263, our next gen KIT inhibitor or either of our EGFR programs or frankly the Roche collaboration.

So, we've guided to the potential for two additional development candidates over the course of this year and think those are still on track based on work being conducted internally.

In terms of timelines, talked about this a bit in the opening remarks that we'll look to share more data on the preclinical programs in the second half of this year both at scientific conferences, but also spend some time elucidating our clinical plans, including that for BLU-945. So, goal is to file an IND late this year, early next year.

And that remains on track, but I think there's more to the research story than any one program..

Excellent. Thank you so much..

I would now like to turn the conference back over to Mr. Jeff Albers..

Thank you, operator. And again, thank you all for taking time to join us today and for your continued support of Blueprint Medicines. And we look forward to updating you again soon. Stay well and goodbye..

Ladies and gentlemen, this does conclude today's conference. Thank you for participating. You may now disconnect..