Good morning, and welcome to Agios' Second Quarter 2020 Conference Call. At this time, all participants are in a listen-only mode. There will be a question-and-answer session at the end. Please be advised that this call is being recorded at Agios' request. I would now like to turn the call over to Holly Manning, Director of Investor Relations.

Thank you, operator. Good morning, everyone, and welcome to Agios' second quarter 2020 conference call. You can access slides for today's call by going to the Investors section of our website, agios.com. With me on the call today with prepared remarks are Dr. Jackie Fouse, our Chief Executive Officer; Dr. Chris Bowden, our Chief Medical Officer; Darrin Miles, our Senior Vice President of U.S. Commercial and Global Marketing; and Andrew Hirsch, our Chief Financial Officer and Head of Corporate Development. Dr. Bruce Car, our Chief Scientific Officer will join for Q&A. Before we get started, I would like to remind everyone that some of the statements we make on this call will include forward-looking statements. Actual events and 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 most recent Form 10-Q filed with the SEC and any other filings that we may make with the SEC. With that, I will turn the call over to Jackie.

Thanks, Holly. Good morning, everyone, and thanks for joining our second quarter 2020 results call. The second quarter was an incredibly productive and important time for Agios as we made significant progress across the business and accomplished several of the key objectives that we set for 2020. The steps we took in Q2 solidified our strategic priorities for the remainder of the year and move us closer to achieving our 2025 vision. Seven years ago, we discovered the first pyruvate kinase-R activator Mitapivat and since then we've led the science behind this mechanism, advanced a Phase 3 program in pyruvate kinase deficiency and became the first company to establish that activating wild type PKR may provide therapeutic benefit and other hemolytic anemia’s, such as thalassemia and sickle cell disease. Over the past quarter, we further underscored our leadership in the space and shared key updates that support our next phase of development for Mitapivat. To start, we established compelling proof-of-concept for Mitapivat and sickle cell disease demonstrating that PKR activation has the potential to treat chronic hemolytic anemia and markers of sickling in these patients. In addition at EHA we presented data for the first time at a medical meeting for Mitapivat in thalassemia showing sustained hemoglobin responses in both beta thalassemia and alpha thalassemia patients. In May the FDA granted us orphan drug designation for this indication. As we look ahead, we are firmly committed to the rapid advancement of Mitapivat across all three of these disease areas. The remainder of 2020 will be focused on preparations for top line data from the PK deficiency Phase 3 studies and the submission of an NDA for Mitapivat first indication, and the indication of pivotal programs in both thalassemia and sickle cell disease in 2021. In June we secured $255 million…

Thanks, Jackie. I'll start with Mitapivat, our first in class PKR activator currently being evaluated across three distinct hemolytic anemia. As Jackie highlighted, we achieved important milestones for this program in the second quarter that support broadened clinical development in both thalassemia and sickle cell disease. Our most advanced program is in PK deficiency, where we have 40 [ph] years of experience in treating patients and have the potential to provide first disease modifying therapy. Earlier this year, we completed enrollment in our two Phase 3 studies, ACTIVATE and ACTIVATE-T. Since the beginning of the COVID-19 outbreak, we have focused on ensuring patients have access to study drug and that we capture all data regardless of a patient's ability to get to their trial center. This includes home visits, telemedicine approaches, the use of local laboratories and courier shipments of drug. As core period of both studies comes to an end later this year, we are working with our global clinical trial sites to understand the timeline to complete necessary steps for database lock. We still anticipate top line data from both ACTIVATE and ACTIVATE-T sometime between the end of 2020 and the middle of 2021. We will narrow this timeline based on our ability to confidently predict trial site access in the wake of the ongoing global pandemic. We expect to file for regulatory approval in both the US and EU next year with the potential 2022 commercial launch and PK deficiency in both geographies. Moving to the Phase 2 study of Mitapivat in thalassemia. We completed enrollment earlier this year with 20 patients and in June we presented updated data on 13 efficacy evaluable patients at the virtual EHA meeting. The data showed that treatment with Mitapivat induced to hemoglobin increase and greater than or equal to 1…

Thanks, Chris. I'm pleased to share that our commercial team has continued to deliver strong performance in 2020 recording $27.6 million of net sales of TIBSOVO in the second quarter, a 22% increase from Q1. Access restrictions related to COVID-19 notwithstanding. Quarter-over-quarter growth was driven by an increase in both new scripts and refills with the largest increases seen in the relapsed refractory AML setting. Furthermore, we continue to expand our prescriber base, growing at 15% in both the academic and community setting over Q1. Market research continues to show that the majority of physicians consider TIBSOVO to be standard of care in IDH1 mutant AML, and the leading target of treatment for newly diagnosed IDH1 mutant AML patients and [ph] eligible for intensive therapy. Though not [ph] a focus of our promotional efforts, we continue to observe that approximately half of TIBSOVO use in both the relapse refractory and frontline settings is in combination and most frequently this occurs with a hypomethylating agent. Our patient assistance program, myAgios, continues to operate uninterrupted in the midst of the COVID-19 pandemic as we support patients through these challenging times. As Jackie mentioned, in response to the growing concerns related to the pandemic, our majority of our field teams continue to work from home since mid-March. Though some have begun to safely interact with their customers in person again, as local guidelines and practices have allowed. We've experienced success continuing to engage customers with tools enabling remote interactions. As a result of performance through the first half of the year, we reiterate our full year 2020 US TIBSOVO net sales guidance of $105 million to $115 million. I'll now turn it over to Andrew to discuss our second quarter financials.

Thanks, Darrin. Our second quarter results can be found in the press release we issued this morning, which I'll summarize. More detail will be included in our 10 Q filing later today. Total revenue for the second quarter was $37.3 million, which consisted of $27.6 million of net sales of TIBSOVO, $6.4 million in collaboration revenue and $3.3 million of IDHIFA royalty revenue. Compared to second quarter of 2019, total revenue grew by 42%, driven by a 101% incease in TBISOVO sales, offset by a decrease in collaboration revenue. As we announced in June, Royalty Pharma purchased our tiered, sales-based royalty rights on worldwide net sales of IDHIFA, as well as rights to receive up to $55 million an outstanding ex-US regulatory milestone payments from BMS for $255 million. This transaction will be accounted for under the debt method which required us to record a liability on our balance sheet for the purchase price net of issuance costs. We will continue to record the IDHIFA royalty to [ph] the life of the arrangement. In addition, we will record non-cash interest expense associated with the liability. The liability will be reduced by the royalty revenue recorded in each period and increased by the non-cash interest expense. For the period in which interest expense exceeds royalty, the liabilities increased and for periods in which the royalty revenue exceeds interest expense, the liability is reduced. The liability will be reduced to zero when we're no longer eligible to receive royalties under the 2010 agreement. TIBSOVO revenue grew by $4.9 million, compared to Q1 2020, which was driven by continued strong unit demand and channel inventory levels returning to more normal levels versus where we ended Q1. Gross to net for the quarter was within the expected range, but we have seen increases in…

[Operator Instructions] Our first question comes from Alethia Young with Cantor. Your line is now open.

Hey, guys. Thanks for taking my question and congrats on the progress throughout the quarter. I guess, I just wanted to ask maybe about Mitapivat and [indiscernible] and kind of any color you can give us on, you know, timing and plans to move forward there? I know you said you're moving forward, but just a color, it would be helpful. Thank you very much.

Hey, Alethia. It's, Chris. I didn't catch, you're looking for an update on which program?

Mitapivat and [indiscernible] Can you hear me now?

Okay. Yeah, yeah. No, I just didn't hear the [indiscernible] part. Right, so we're looking to initiate a trial on pyruvate kinase deficiency next year. The process of negotiating the study design and with both Europe, where the crucial part of - it's a box you have to check in order to be able to file an adult [ph] indication and then you make a commitment that you have to be strictly commit to, it takes a while and so we're working through that. But we anticipate opening that trial in 2021. And then our plans in thalassemia and sickle cell are will embarked on pediatric development are still coming together.

Oh, sorry, PKR team [ph]

Yeah.

Yeah, okay. Got it. Okay.

So we're going to - we're targeting opening a trial in children pyruvate kinase sufficiency next year. And then we will also do pediatric development with Mitapivat and Thalassemia and sickle cell, but those plans remain to be defined at this point.

Okay, got it. Cool. Thank you.

Thank you. Our next question comes from Anupam Rama with JPMorgan. Your line is now open.

Hey, guys. Thanks for taking the question. And congrats on all the progress. I had a broader kind of sickle cell question and thinking about Mitapivat, one of the most frequent questions that we've gotten, post EHA, isn't it? How do you ultimately think about levers for differentiation, whether it's against other PKR activators, as well as established players like GBT, for example? Thanks so much.

Hey, Tom, it's Chris here. I'll start and some others may want to jump in. I think that the ability for Mitapivat is really looking at two factors. And that would be increasing hemoglobin for patients who are experiencing anemia as a basis of their disease. And of course, their - the occurrence of acute chest syndrome, pain crises and all those things, aspects that really are part of the unmet need. So the best case scenario for us and our early development data for from the NIH study suggests we have the potential to affect both. With regards to competitor PKR activators, it's really going to boil [ph] down to a number of things, is that we've got four years plus data with Mitapivat and we're getting ready to put a follow-on for children [ph] to the clinic. We know a lot and then the leaders in defining the biology, the translational science, as well as clinical science. So that's really going to I think shakeout as additional data emergence. And I think that's the safety and efficacy profile and setting when you're getting drugs for long periods of time is really important. I think the other thing that we may see, depending on how many additional drugs come on the market will be, targeted therapies could potentially be combination therapy, that something else in a distance. And then finally, you asked about how do any of these drugs fit in, given the presence of Oxbryta [ph] And that's a drug that has accelerated approval, to date has shown an increases in hemoglobin that were sufficient for accelerated approval in about 50% of patients. So if you just step back for a minute then, that it did not show any improvement, statistically significant improvement in the reduction of VOCs. So if you just step back for a minute, there's - and you look at the potential Oxbryta population, you can say that at least half of those patients are going to have an adequate response and that can establish a patient population for you right there.

This is Darrin, maybe just add one more point to what Chris laid out. I think he made the most important points. In terms of differentiation in class, I mean, ultimately, you'll come down to data, the advantage that we have is going to be the depth and breadth of our patients experience, right, because we'll have one, two indications, and the product will be very familiar to the treaters, before hitting other potential in class competition, makes it to market. So I think that adds considerably to raising awareness, similarity [ph] comfort with Mitapivat relative to other products.

And this is Bruce Car. Just adding to that, important within the – with in class differentiation is the uniqueness of the mechanism of action of the allosteric PKR activators. So, while we improve the health of the cells, we improve the ATP content so, the energy of the cells and learning 2, 3-DPG we directly improve the affinity of the hemoglobin for oxygen. This is complimentary to the mechanisms that increase in blood and adds like hydroxyurea and others. So, we believe ultimately these mechanisms will be complimentary, potentially even synergistic when combined to which others have alluded.

Great. Thanks so much for taking the questions.

Thank you. Our next question comes from Tyler Van Buren with Piper Sandler. Your line is now open.

Hey, guys. Good morning. I had a follow up related specifically to the Mitapivat, sickle cell program, you noted that enrollment was halted, but that it should reopen this summer, which to mean, potentially in, you know, a month or so, and that they eventually plan to enroll 25 patients, but it's unclear how many above nine you'll be able to get before ASH. So can you just talk through that a little bit more? You know, what gives you confidence that it should reopen this summer, relatively soon. And then just maybe walk through the time that would be required on study for these patients to get more above that nine number in time for ASH? Thank you.

Hey, Tyler. It's Chris here. I think the reason why we think the study will reopen is because of the communications that we're getting from the NIH and from Dr. Thein's [ph] group and that they're anticipating that the center should open within the next several weeks. And then I think the second part of your question is, so then what's the - what's the data flow look like? And that would depend on how many patients they can consent, enroll and are permitted to treat. And that may be a function a, I don't know, whether the NIH is going to - my guess is that they will be doing a stage reopening. And so really, the number of patients that can come in will be - to be an administrative issue. That overall, then patients come in, they have some baseline testing, and then they're going to get treated for eight weeks, have the taper and then they go off. So in terms of how many patients will be added to any ASH presentation will really depend on how early they open, or how early in the remainder of the summer do they get open and now many people can make consent and bring in, add on eight weeks of treatments and taper time and then they of course need some time to pull things together, and in order to get it ready for a presentation in December. So early, early days now, we're encouraged by the fact that they are pretty confident they're going to get open in next couple of weeks. And Dr. Thein is working on having patients lined up to come in and they have some experience now with the drug. So we're keeping our fingers crossed that we'll be able to get a few more patients in, but we know at a minimum it will be the details on the patients we talked about at EHA meeting.

Okay, that's very helpful. Thanks so much.

Thank you. Our next question comes from Peter Lawson with Barclays. Your line is now open.

Thank you, thanks for taking the questions. Just on TIBSOVO and the revenues and the number of unique subscribers. Is there anything you can talk through with regards to the impact from COVID? And anything you can say that off label use? Thank you.

Sure, its Dan here, so we haven't been able to detect a significant impact from COVID thus far. We’ve seen nice growth in new scripts and refills both of which are continuing to move in the right directions. As we noted, we had a very significant expansion of new prescribers in both the academic and the community setting, but it's the fastest – the growth is actually occurring in the in the community setting, which is encouraging as well. The - there are a couple of risks though that are associated with COVID, right. So ultimately, we have yet to see it. But there potentially can be an impact in terms of the initial diagnosis of patients with AML. Though it's a treatment emergent disease, the reluctance of patients to show up could potentially manifest over time, but we haven't seen that significantly as of yet. The continued work from home restrictions on the sales force can potentially add some pressure. But what we've seen also is an increase in Medicaid and 340B utilization as well. And we would expect that to continue as Andrew indicated earlier. And then in terms of spontaneous adoption, off label use and other settings, as because we've shared many times, we've limited insight into utilization in indications outside of AML, but we do have antidotes of those uses.

Great. Thanks so much.

Thank you. Our next question comes from Kennen MacKay with RBC Capital Markets. Your line is now open.

Hi, thanks for taking the question. Maybe I was just hoping you could discuss a little bit more in sickle cell, the real sort of urgent need for tapering, really any medication that is used to sort of bolster the number of red blood cells in circulation, especially if this is acting by shifting the oxygenation curve of red blood cells and oxygen binding, because that's something that I think is still maybe a little bit underappreciated in that setting? Thank you.

Kevin, this is Chris here. So you are asking the question of tapering.

Yeah, I'm sorry, on discontinuation of drug. Yeah, just going back to some of the safety events that we saw in sickle cell.

Yeah. Well, you know, we established with Mitapivat and pyruvate kinase deficiency, that the best thing, the ideal situation is the patient is going to start drug is to gradually taper. And if you think about it, then you've got a drug that’s binding and stabilizing pyruvate kinase in the setting of pyruvate kinase deficiency here and then activating it in all these diseases. So abruptly stopping and has potential for a more rapid decline in hemoglobin limit to taper it and a rapid decline then the patient can acclimate, as rapidly - can't acclimate as well, as if you do a slow taper. So that's really where that comes from. Now, the aspect of one of the things I think that comes up is people are worried about compliance, because of the statements and data that indicates that, that non-compliance may be more of an issue in sickle cell versus other diseases. We don't think that missing a dose here and there is likely to be a problem, based on what we know about the pharmacokinetics and the biology of the molecule. But I think that's the guidance that in the ideal situation, you want to avoid abruptly stopping the drug and have tapers like them to be present. I would also say that's true for a lot of drugs, whether they’re in the hematologic space or other areas where chronic dosing is something that you do.

And maybe just as it relates to be competitive landscape, here, just to hot to - in one way, at least, one of the mechanisms of Mitapivat is a little bit similar to the mechanism of Oxbryta, shifting that oxygen affinity for partial pressure curve. Can you maybe talk a little bit about the theoretical combined ability of these agents, whether that's realistic, there's something that wouldn't make sense? Thanks so much, and congrats on the progress during Q2.

Yeah, well, I think I think the combine ability is something that we're interested in, not just in sickle cell, but thalassemia, as well as new products come on. And I think that is the complementarity of mechanisms of action. So you know, if you're infused with thalassemia example, first, if you have something that enhances terminal erythroid differentiation like luspatercept is there at least a theoretical interests that by having more cells get to that late stage so that they can be affected by that drug luspatercept, and then that's certainly of interest. There's been recent publications in the sickle cell literature where people are saying this the number of new drugs coming in as offering some real potential for complementarity. Specifically for Mitapivat and Oxbryta, it's an interesting thought. If you can get somebody up a gram with spread [ph] or gram and a half, will they benefit from another gram and a half by adding PKR wild type activation on Mitapivat. And on the one hand that's appealing and then the other hand, you've probably heard from sickle cell Doc's is that they're a little more careful about how you know, they adjust hemoglobin in these patients. So yeah, it's definitely of interest not just for Oxbryta, but potentially for other drugs that come along, whether it's the Novartis P-selectin inhibitor and others, but I think that you know, we - just based on our data and now in sickle cell that the early day that we talked about at ASH at EU [ph] and what we see in thalassemia, and our long term experience with Mitapivat and pyruvate kinase deficiency, I'm very excited about just looking at this drug as a single agent, because I think that we have the opportunity to do both, to address both major components of the disease and reduce that, you know, that hyperactive bone marrow that's really working hard to keep up with anemia. I think there's a potential that we can demonstrate the patients will feel better as well. So yes to combinations, but I think we have very strong, very strong grounds to think that we have a single agent benefit that we'll be able to provide to patient.

And, and just carrying on from that, Chris, the patient reported outcome is being in a favorable, very favorable anecdotally for treatments with Medicaid Mitapivat across the indication. That isn't the case with Oxbryta. Notwithstanding its approval for increasing haemoglobin. And important is that the [indiscernible] haemoglobin, it prevents the sickling. So that's a very important thing. But it also lowers the ability of haemoglobins to carry oxygen. And that's very important. And we’re able to preserve hemoglobin in healthier red cells such that they carry more oxygen and that there's a higher affinity is the binding for oxygen. So we believe we have actually a superior mechanism there to that of Oxbryta.

Thank you. Our next question comes from Chris Shibutani with Cowen. Your line is now open.

Good morning. Thank you. Questions focused on Mitapivat, three of them. For Mitapivat you have previously updated on the Peak Registery and patient identification any updates there. You've also described narrowing the timelines based on ability to access trial sites to get the ACTIVATE data, that was an assessment you obviously had to make three months ago. And just curious to know whether thus far your centers that progress has been quicker, perhaps then you thought or more challenging? Any color in terms of an update on how that progress is, I know you gave us the first half of the span. Secondly, for sickle cell disease, you have this collaboration with the NIH, can you just remind us what optionality do you have, any plans that might be in place to do clinical work in this indication, independent of the NIH or are you tethered to them contractually, just help us understand, since I think a lot of the sharing of data is dependent upon decisions directly made and perhaps if you had options to direct trials and activities on your own, that would be helpful for us to know/ Thanks.

Okay, Hey, Chris. Chris Bowden, here. Peak is up and running at multiple countries across the world. It's enrolling well. One of our ambitions is to take the natural history study, and be able to pull those data with Peak, its something we're working on. That database is from the Boston Children's Hospital. So merging that into or combining that and pulling it and doing analyses is something that we're interested in doing and hope to talk more about in the future. So - and we think that's going to be an important, an ongoing, important data sets for us to describe the burden of disease outcomes, variations and treatment approaches. And we're looking forward to starting to be able to publish them and hope to be able to guide to that. With regards to the challenges and then the ups and downs of clinical development in the global pandemic. As I commented on in my remarks, I can't talk about specific places, specific sites. But if you just step back for a minute, and you look at how the pandemic has lost the United States as it moves from the east coast and the west coast, down to the south, and up and around, there's a fair amount of unpredictability there. And depending on how lock down at hospital is, and how they're managing clinical trials and their clinical research staff, and the fact that when they stop and then start, there's a queue. Those are the types of factors that we're looking at, and trying to understand how we're going to get in there and pull the data and that's why we can't provide any more guidance at this point. But what I can tell you is that, we've done a good job in terms of making sure patients stay on drug, capturing data by any of the means that I talked about in my prepared remarks. And, you know, we'll just have to see how things develop before we can provide you a more definitive guidance, which is why we didn't update it on this call. And then with regards to the NIH and issues around, how we choose to do development, and we don't have any restrictions, I mean, that's a CRADA agreement we have with them for a trial, we freely share the data, we're in fact, performing a number of the assays are being done with Bruce’s group. So, you know, we have freedom to operate and we're moving forward expeditiously to get a sickle cell trial up and running in 2021. That's not dependent on any way of an approval from the NIH. And for that matter and we have a very good relationship with them and being able to discuss and describe that data and present it to help employees as needed.

It's Jackie. I just wanted to jump in for a second. And I think something Chris said is really important to just reiterate on the ACTIVATE, ACTIVATE-T trials, you have two issues that you probably want to think about. One is data integrity. And that is where Chris spoke to how good a job our team has done to make sure that patients stay on drug, and that the trial, you know, they finish their trial experiences smoothly and in line with the protocol. And then the second is timing and being able to release that or have in hand, analyze and release that top line data. So I think data integrity is extremely important if we were fast at getting it the data out that there was compromises to the data that would be more serious than ensuring data integrity first and then the timing when we get that top line data out. And we're, as Chris said, we feel good about that what the team has done to support data integrity, and we haven't narrowed the timing window just yet, because we've got a little ways to go to get into those sites and see that. And then I think also Chris, part of your first question included the patient finding efforts and right now between our clinical programs and our patient finding efforts we’re at about 2000 patients identified.

Thanks. Thank you for the update.

Thank you. Our next question comes from Mohit Bansal with Citi group. Your line is now open.

Hey, good morning, guys. This is James on for Mohit. I had a question on AG-270. Another company recently announced a collaboration to explore MAT2A with PRMT1 and they published some preclinical data showing greater potency and solubility compared 270. Have you seen this data? And what are your thoughts on their MAT2A program and possibility for a combo with PRMT1?

This is Bruce Car. I believe you're referring to the IDO [ph] molecule. Yes, in terms of this ability, this pathway to lower [indiscernible] the combination with PRMT1 is an entirely appropriate one. And we believe also PRMT5 could be a potential player in this field.

Thank you.

Thank you. Our next question comes from Michael Schmidt with Guggenheim. Your line is now open.

Hey, guys, thanks for taking my questions. I had two more on sickle cell and one on TIBSOVO. Maybe a little bit of a follow up to a prior question, on the Phase 1 NIH data, I was just wondering if any additional information might be available on that that one patient that experienced a VOC event, I think at the time it was classified as possibly treatment related. But obviously, VOCs occur at high frequency in patients in general. I was just wondering, Chris, if there's been any new information on that specific event that you might be able to share?

Nothing new. The VOC occurred during the taper. We didn't see any events while patients were on active treatment. You're absolutely right, that's an unfortunate component of disease in one way trying to address which is the VOC's. We didn't see any additional ones during the taper or over the course of those eight patients that were able to completed their there six or eight weeks of dosing. No, so no new information. And it's something we'll continue to track. And I think, you know, given our overall sense of that data that we've talked about it at ASH is that we clearly achieved proof-of-concept and we're excited to move forward.

Great, thanks. And then I think you mentioned meeting with the FDA and discussing our plans for regulatory trials or approval or pivotal trials. And you know, given some of the possible, you know, differentiation that was talked about earlier. Just wondering how you think about, you know, taking advantage of that in your trial design, for example, you know, what are your thoughts about pursuing an accelerated approval pathway similar to GBT, using HB increase or potentially incorporating clinical outcomes, such as VOC reductions, I guess, how do you think about those considerations?

Yeah, that's the major focus for our team now in terms of putting together a clinical development plan that can lead to approval, accelerated or regular in United States, but in other geographies outside the US. And you know, that interesting part of Mitapivat is that we have the potential to - we clearly have the potential to address capable of when we demonstrated that early on and we know now that activating wilds type PKR is a important strategy in chronic hemoglobinopathies, overall, if you will, mainly thalassemia and sickle cell we've demonstrated so far. We think that we have the opportunity to reduce VOC. So then, so what, I'm not saying anything new here. The interesting part is how you combine those, as well as potentially patient reported outcomes into a package that can get you there as rapidly as you can, but also have the greatest impact on patients. So we're working hard on that. And we're looking forward to having those discussions with both agencies as rapidly as possible. The other thing that they want to do is get input from patients and patient advocates, because I think that that's going to have an important impact on the type of data that were – that will impact patients and really compel them to use the drugs. So a lot of factors in play. I know that accelerated approval and then basically increasing hemoglobin has been demonstrated with Oxbryta. And that's something that we're looking very hard at. But we think there's a lot more for us to be thinking about on the basis of the mechanism of action of Mitapivat and the unmet need overall.

Okay, great, thanks. And then a commercial question on TIBSOVO. I'm just curious if you could share what market share now is in either you know, frontline and also relapse/refractory AML. Since it seems like you've seen growth in both, just curious what market shares at the moment? And then also wondering if you've already been seeing use in cholangio based on the recent NCCN listing?

Sure. So Dan, here. So, you know, given the population in our distribution or visibility into utilization, I can't - I don't know exact penetration numbers by line of therapy. What I have are reflections of physicians through market research and their use by setting. So I can't give you exact kind of penetration number. But what I do see is the change in utilization, as stated by physicians over time and so that's when I make statements about increased adoption - increased adoption in different settings, that's what I'm relying on. And what we've seen is continued adoption and continued improvement or increased adoption to say in the frontline setting and by spiking in the relapse setting as well. And we've seen that change in the last quarter increased use of the product in combination with HMA as well. And then in terms of utilization in cholangio. Yes, we've heard - we've had antidotes of utilization and in the cholangio setting as well. And given the recent NCCN guidelines, it wouldn't be surprising if we continue to see adoption there as well.

Okay, great. Thanks for taking my questions.

No problem.

Thank you. Our next question comes from Mark Breidenbach with Oppenheimer. Your line is now open.

Hey, good morning, and thanks for taking my question. Congrats on the forward progress. Maybe just another Mitapivat question, following up on one of Kevin's questions. It sounded like you're not really worried about potential for a rebound effect in sickle cell patients who miss dosing for a day or two. I guess I'm left wondering what's giving you confidence around that statement. And I'm also wondering why drug taper doesn't appear to be necessary for patients on Oxbryta, any speculation as to why they can get away without a taper would be very helpful? Thanks so much.

The reason - it's Chris here, the reason why we don't think missing a dose or two here or there is based on what we've seen - what we know about drug binding to enzyme and sticking, what we know about when you look at effects from our healthy volunteers study, for example, when we look 2,3-DPG and ATP levels, after patients had stopped dosing, they actually stayed elevated for several days. So I think that's some of the data that gives us gives us confidence that we don't think that's going to be an issue. That as you miss a dose and suddenly you have a - you get into some sort of withdrawal problem. And then the second part of your Oh, yeah, Oxbryta, why do they not have to taper? Well, Bruce may want to comment on that. But one of the things that is interesting is that when you look at some of their Phase 1 and 2 data, you will see that there are VOCs that occurred as patients were coming off drug, they just haven't attributed to drug and investigators think it's not drug related. So that's about all I can say about that. And I think that the, the main thing for us in terms of differentiating versus that drug - versus Oxbryta is going to be a percentage of patients that have a response to Mitapivat versus Oxbryta, if both drugs are available in the marketplace. The overall activity versus VOC, whether we can demonstrate that or not, and whether with longer follow up, they will be able to. And then there are other aspects of how the patients feel better taking these drugs. And I think from as I've commented earlier on, if we can increase hemoglobin and address VOCs with a pill that you're taking twice a day, that we think that has a pretty good compelling reason to use

And just disagreeing with you today, Chris. The very long pharmacogenomic effect of Mitapivat is the reason why individual miss doses in the BIC [ph] schedule are not going to matter. The mechanism of action between Oxbryta and Mitapivat are quite different. And I mentioned previously the covalent binding to the veiling end of the [indiscernible] with Oxbryta is a permanent binding. That's what's meant by covalent binding. And it will persist for the entire lifespan of the hemoglobin which is longer than 30 days in the case of hemoglobin S bound to Oxbryta.. That's possibly a reason.

Thanks so much.

Thank you. Our next question comes from George Farmer with BMO. Your line is now open.

Hi, thanks for taking our questions. This is Govind on for George. Just on the same theme as a prior colleagues that were asking, with the VOC patients, If I remember correctly, I think the titratation, the taper protocol was 12 days. So perhaps you might be willing to comment on was that VOC patient during the latter half, perhaps of the 12 days? And that's maybe where you're getting your confidence that, missing a single dose or not probably really not going to matter? And then, if I remember correctly, I think you guys mentioned two patients had been dosed on the 100 milligram protocol right before the COVID-19 shutdown happened. I was wondering if you guys have seen any of the hemoglobin responses. If I'm understanding that correctly in those patients? Because it seems like there's a really strong dose response relationship and wouldn't be surprised the increases are better there? Thank you.

The patient who experienced the VOC did indeed have it to the closer to the end of taper, then at the beginning. And I think that qualitatively that's in line with what you just heard Bruce and I talked about with regards to the ability to tolerate and not have untoward effects for missing a dose or two or, or several doses of Mitapivat. What we talked about at EHA [ph] was that we gave the data that seven of the eight patients treated in that trial had an increase in hemoglobin, and that five of eight had an increased over a gram. And that was across all the cohorts. So we didn't provide individual data because we want to, we want to save that for the ASH presentation, to give that presentation. The most power that it can to get a good slide at the meeting. So your questions I a great one, does going from 50 milligrams to 100 milligrams or 200 milligrams is what is the - is there and what is the extent of that, that dose response relationship and with regards to whether it's hemoglobinuria impact and oxygen dissociation curves, that's something we'll look at. It would be too early, like I said, I can't comment on the hundreds versus the patients only 1 to 50. And it's a small patient number. We're going to want to see additional patients and as we think about those question in sickle cell.

I will remind you that in thalassemia, we - in that protocol, we went from 50 to 100. And we saw some slight you know, suggestions that we may be seeing a little more bump when you go from 50 to 100, whether that same thing will occur or something different sickle cell it remains to be seen. The thing we know about Mitapivat, that I think it's really, it gets back to the way you always hear me talking about the safety of the drug. And we understand the safety profile across many years now from dosing and expansion, and the drug PK study. But we also know that there's a range of doses that are pretty well tolerated and are suitable for development. And I think that the, you know, the nuances of the of PKR in the context of the individual diseases, such as the pocket [ph] there may be a range of doses that clinicians who want to be thinking about this, they balance optimizing efficacy with safety. So it's - I have a lot of comfort with having worked with this drug now for several years and looking at the safety profile. So it's a very interesting question and yeah, we just need more data. But we know there's range where we can go to this drug and it's pretty well tolerated.

Thank you.

Thank you. I'm not showing any further questions at this time. I would now like to turn the call back over to Jackie Fouse for any closing remarks.

Thank you, operator. Thank you all for joining us on call this morning. I would like to reiterate that despite the challenges and uncertainties that lay ahead of us all, I remain incredibly excited about the progress we've made in Agios across our focus areas so far this year. To close I would like to thank the tremendous employees at Agios for their dedication and passion for making a difference for our patients, particularly during this uncertain time in the world. I also want to thank all of the patients, caregivers and physicians who participate in our clinical trials without them, we cannot do what we do. Thanks again for joining us today. We look forward to seeing you and hearing you soon. Take care.

Ladies and gentlemen, this concludes today's conference call. Thank you for participating. You may now disconnect.+