Greetings, and welcome to the Rigel Pharmaceuticals Financial Conference Call for the Second Quarter 2022. At this time, all participants are in a listen-only-mode. A brief question-and-answer session will follow the formal presentation. [Operator Instructions] As a reminder, this conference is being recorded. It is now my pleasure to introduce our first speaker Dolly Vance, who is Rigel's Executive Vice President, Corporate Affairs and General Counsel. Thank you, Ms. Vance. You may begin.

Welcome to our second quarter 2020 financial results and business update conference call. The financial press release for the second quarter was issued a short while ago and can be used along with the accompanying slides for this presentation in the News & Events section of our Investor Relations site on www.rigel.com. As a reminder, during today's call, we may make forward-looking statements regarding our financial outlook and our plans and timing for regulatory and product development. These statements are subject to risk and uncertainties that may cause actual results to differ from those forecasted. The description of these risks can be found in our most recent Annual Report on Form 10-K for the year ended December 31, 2021, and subsequent files - filings with the SEC, including our Q2 quarterly report on Form 10-Q on file with the SEC. Any forward-looking statements are made only as of today's date, and we undertake no obligation to update these forward-looking statements to reflect subsequent events or circumstances. At this time, I would like to turn the call over to our President and CEO, Raul Rodriguez. Raul?

Thank you, Dolly, and thank you, everyone, for joining today. Also with me today are Dave Santos, our Chief Commercial Officer; Dr. Wolfgang Dummer, our Chief Medical Officer; and Dean Schorno, our Chief Financial Officer. On Slide 5, we are also very pleased to have Dr. Jorge Cortes joining us today to provide a clinical perspective on our recently acquired pipeline addition olutasidenib. Dr. Cortes is an internationally recognized expert in the leukemia and has led the development of numerous leukemia treatments, including for [indiscernible] an inclusive [ph] who were used during the treatment of chronic myeloid leukemia or CML, and Turismo [ph] who is a treatment for older patients with acute myeloid leukemia or AML. Dr. Cortes is currently the Director of the Georgia Cancer Center, which he joined in 2019 after spending 23 years at the University of Texas MD Anderson Cancer Center, where he held many roles in the Department of Leukemia, the vision of cancer medicine, including Deputy Department Chair and the Chair of the AML and CML sections. In addition, he was the Deputy Division Head for the Cancer Network and Chair of the Executive IRB. Importantly for us today, he is a clinical trial investigator on the olutasidenib trial. Beginning on Slide 6. I am pleased to report that we have made significant strides this quarter in growing our commercial hematology, oncology business. I'll start with our first value driver on this slide, growing ITP sales. During the second quarter, Rigel achieved the highest quarterly net product sales for TAVALISSE in ITP since launch. This demonstrates the continued momentum we are driving through our commercial activities with hem/onc prescribers. As you may recall, last year, we undertook a sales force expansion to broaden our reach, improve efficiency and increase in-person interactions. These initiatives are…

Thank you, Raul. Now I'd like to take a few minutes just to highlight why we're so excited for he prospects of expanding our hem/onc portfolio with olutasidenib. Moving to Slide 9. Our collaboration with Forma aligns with our strategy of expanding our portfolio of hematological therapies, while leveraging our existing commercial infrastructure. As Raul touched upon, in the past year, we made key strategic investments in our commercial organization to expand our sales force and sharpen our BD focus to prioritize late-stage development programs that would be a good strategic fit for us. As a result, we are well positioned to add olutasidenib to our product profile. On the left, we have strategically experienced business operations and marketing teams that can quickly gather insights and synthesize those into actionable plans that will ensure a strong launch, even with a shorter runway. In addition, we have a highly experienced and customer-focused patient access team that has everything in place to efficiently distribute olutasidenib and ensure patients have access to coverage, reimbursement and assistance. Finally, we have a very oncology tenured field team already calling on the majority of hematologists and oncologists in the U.S., enabling us to realize cost efficiencies, while potentially bringing two important products olutasidenib and TAVALISSE to the attention of our customers, a proposition, we believe, can increase the overall awareness and utility of both. In summary, we have the team in place to successfully launch olutasidenib, which is critical since we have a product that could be approved in just 6.5 months. On Slide 10, I wanted to share why AML was a very interesting disease for us to enter. As you may know, AML is an aggressive, highly complex malignancy and primarily a disease of older adults. In 2022, the American Cancer Society estimates that…

Thank you very much. And my name is Jorge Cortes. As mentioned, I am currently the Director of the Georgia Cancer Center and formerly MD Anderson in the Department of Leukemia, where as the Deputy Chair, and I was there for 23 years on faculty plus my training before that. So I'll be very glad to discuss with you this drug olutasidenib and the role of in patients with IDH1 mutated acute myeloid leukemia. So I'll start with the background on Slide 14. As a reminder, IDH1 mutations occur in somewhere around 8% to 12% of patients with acute myeloid leukemia, you can see depending on different sources and different patient populations, the range may expand a little bit more from somewhere to 6% to 16%. And that's about where we see this type of mutation. As already mentioned, olutasidenib is very important and very select inhibitor of IDH1 mutated. And I will remind you how IDH1 mutations work in acute myeloid leukemia, it's very important because this is one of those mutations that are considered initiating mutations. There are some mutations that happen a little bit later after a leukemia has been developed and some that are initiating mutations, and we think that IDH1 mutations are one of those. That's important because that goes to the root of the development of acute myeloid leukemia. Normally, as you all may remember, from the - from biochemistry, we have this Krebs cycle, which is the metabolism of the normal cells. And it goes to alpha-ketoglutarate and when IDH, which normally metabolizes alpha-ketoglutarate, when it is mutated, it transforms alpha-ketoglutarate into two hydroxyglutarate l or 2HG and when that metabolite 2HG is usually not present in normal cells, in the normal cycle. When it is formed, it has the potential to transform…

Thank you very much Dr. Cortes for your thorough review of our data. We really appreciate all of your insights. And I know there will likely be questions as we move to the end of the call. So I just have a few brief comments on TAVALISSE progress in Q2. We're actually quite excited about that as well. On Slide 25, you'll see our FDA-approved indication, which is for adult patients with chronic immune thrombocytopenia or cITP, who have had an insufficient response to a previous treatment. Moving to Slide 26. Q2 was the third quarter in a row that we achieved a high in bottles shipped to patients in clinics. We were happy with the growth trajectory we saw in Q1 and then it accelerated in Q2. Our 2,054 bottles shipped to patients and clinics represented a 21% growth over Q2 of last year and 12% over Q1 of this year. That was our highest sequential demand growth in two years. Our demand growth continued to be driven by the increase in patient starts we've been generating since Q4 of last year. We achieved net sales of $18.6 million, a 9% increase over the same quarter last year. So we're very pleased with the continued positive momentum we're seeing in our ITP sales, and I'd like to thank our commercial team for all of their collaborative work to grow TAVALISSE. On Slide 27, you see how our customer interactions have also continued to grow in Q2, particularly with respect to our in-person interactions. Our team grew our in-person interactions another 30% beyond Q1, and those made up more than three quarters of our total interactions with customers. So overall, in Q2, our double-digit demand growth over Q1 created a new quarterly high in net sales for TAVALISSE. We've been focused on leveraging every opportunity to impact customers with our key messages on TAVALISSE's efficacy and safety, along with our preferred status on key national formularies. These messages have been effective in raising awareness and reimbursement confidence among prescribers and resulted in more new patients on TAVALISSE. Thanks for your attention, and I'll now turn the call over to Wolfgang to provide a brief update on our development progress. Wolfgang?

Thank you, Dave. I will provide the update on the other ongoing programs and start with our Phase 3 AIHA study. Slide 29, in June, we reported that the FORWARD Phase 3 study in warm AIHA did not meet its primary efficacy endpoint. Importantly, the safety profile was consistent with prior clinical experience and no new safety signals were discovered. Overall, we have shared our belief that the results were negatively impacted by a large placebo response rate, particularly in Eastern Europe. Since the top line announcement, we did a large number of additional analysis in order to understand the data in greater detail. We will discuss the previously shared data and all new reanalysis data in detail with the FDA this fall to determine the path forward in AIHA. We continue to believe the totality of this data may still allow for a positive overall benefit risk assessment for fostamatinib in AIHA. Shifting gears now to our COVID-19 program. Moving to Slide 31. We are still confident that fostamatinib can provide therapeutic benefits in COVID-19. Most importantly, based on the published positive clinical data from the NIH/NHLBI Phase 2 study in hospitalized patients with severe COVID. Given persistent resistance to vaccination in some places and the possibility of new virus variants, there will continue to be severely even hospitalized patients who need effective treatment options. We have two ongoing Phase 3 trials that will provide us with pivotal data. And if approved in this indication, our lease would be available for immediate use for these patients. Slide 32. Due to the recent slow enrollment, we completed randomization into our pivotal Phase 3 study at 280 patients, which is 91% of our targeted enrollment. The original enrollment target was 308 patients. However, we determined the trial would be sufficiently powered to returning 80 patients to potentially provide a clinically meaningful result and determine the efficacy and safety of fostamatinib in COVID-19. As mentioned earlier this year, we updated the inclusion criteria for the trial to focus on more severe patients and change the primary endpoint to days on oxygen for a more sensitive measure and better comparisons to the NIH active trials. There are also multiple secondary endpoints to assist the important mortality risk, as well as improvement from severe disease and duration of hospitalization for ICU stay. The follow-up period is through the 60 after the last dose. So we expect to have top line data in the fourth quarter this year and plan to file an EUA if the data is positive. That concludes my development summary today, and I will turn the call over to Dean. Dean?

Thank you, Wolfgang. I'm on Slide 34. For the second quarter of 2022, we shipped 2,053 bottles to our specialty distributors, resulting in $26.4 million of gross product sales. 2054 bottles were shipped to patients and clinics, while 924 bottles remained in our distribution channels at the end of the quarter. We reported net product sales from TAVALISSE of $18.6 million, a 9% increase compared to the same period in 2021. Our net product sales from TAVALISSE were recorded net of estimated discounts, chargebacks, rebates, returns, co-pay assistance and other allowances of $7.9 million. Our gross to net adjustment is approximately 29.8% of gross product sales for the second quarter of 2022. Before we move on from net product sales, let me review our expectations for the third quarter of 2022. We are pleased with the continued strength of our bottles shipped to patients and clinics that Dave described. I expect growth to continue as access to physicians and new patient starts continues to expand. We also expect to receive a $2.5 million milestone payment during the third quarter, relating to the enrollment completion in the Phase 3 COVID-19 study, which is supported by the U.S. Department of Defense government grant. Incrementally, we currently expect our gross-to-net adjustment to be approximately 30% in the third quarter of 2022. On to the next slide. In addition to net product sales, Rigel's contract revenues from collaborations were approximately $11.3 million for the three months ended June 30, 2022, which consisted of $7.5 million from Kisse, which included the $5 million milestone for the NDA filing in Japan. $2 million related to our license agreement with Knight, $1.4 million from our collaboration agreement with Grifols and $300,000 of our license agreement with Lilly. Moving on to costs and expenses. Our cost of product…

Thank you, Dean. To conclude, this quarter, we made significant advancements in growing and expanding our hem/onc focused business. First, we achieved the highest quarterly net product sales for TAVALISSE in ITP since launch, and we are well positioned to maintain that momentum in upcoming quarters. Second, we are very excited about our strategic in-licensing of olutasidenib and potentially bringing a new and important treatment for patients with AML. Next year, you may see Rigel with two highly synergistic products, which may enable greater success of both and more fully leverage our commercial capabilities. We also remain committed and focused on advancing our other portfolio programs. We continue to analyze the Phase 3 AIHA trial data and look forward to discussing our filings with the FDA. We believe that fostamatinib has the potential to help patients with warm AIHA in a very meaningful way. With our Phase III COVID-19 trial having completed enrollment, we expect to report top line results in the fourth quarter of this year. And lastly, we continue to drive our two earlier clinical programs, R289, our IRAK 1/4 inhibitor. While we expect to enter Phase I/II trials in Q3. And with R552, our RIP inhibitor, we look forward to this program moving into Phase 2 clinical development, which we expect to happen in the first half of next year. So with that, let me turn the call over to your questions. And if I may ask, since Dr. Cortes is with us, if you have questions for him, let's put those first in your call sequence. Operator?

Thank you. [Operator Instructions] Thank you. Our first question is from Eun Yang with Jefferies. Please proceed with your question.

Thank you. So for this AML opportunity, you guys are mentioning at least on the slide, the near term opportunity is about 1,000 patients in the U.S. So what are you thinking about - how are you thinking about the pricing, number one. So - and how fast you can actually penetrate 1,000 patients once you launch the product upon approval? And the second question is for Dean. The $2 million upfront payment, is that going to be amortized? Or is it going to be booked at once? And I guess like, you know, the regulatory milestone to be booked at once, but can you comment on upfront payment, how it's going to be booked in the income statement? Thank you.

Thank you. Eun, Appreciate that. Let me ask Dean to answer that one first, and then I'll ask Dave to answer your first two questions on pricing and how quickly you might be able to penetrate that relapsed refractory market in IDH-positive AML?

Yes. Hi, Eun. The upfront payments we expect, the pre-approval milestone payments that I described, we expect to be included in operating expense, and therefore, the upfront $2 million, the $2.5 million of the near-term regulatory milestones, we expect those in the back half of this year. And the guidance I gave with respect to operating expense and the small increase from in Q1, Q2 levels are inclusive of those – that $2 million and $2.5 million cost. So that's built into the operating expense feedback that I provided.

Thanks. Dave?

I think - thanks for the question, Eun. I think from a pricing standpoint, obviously, we just did the transaction. So we're not going to release any information as price. But I that, if you look at targeted therapies in AML, that's probably a good target for you. I mean they're all in a similar neighborhood. And so that is probably the best that I would say. There's been seven approvals of oral agents over the last 5 years. And I think particularly when you look at targeted agents in IDH1, IDH2 and LT3 and particularly even in the relapse setting, I think those are sort of the numbers that we've been looking at and we'll be discussing as we move forward. But certainly, no decision has been made. In terms of uptake, I guess the best thing I can tell you is that the first quarter on launch with another IDH1 inhibitor, and this is when there was less information out there on IDH1 less testing, less identification, today its standard and widespread. There were 100 new patients on the product, at least that's what the original, if you look back at that earnings call in the first partial quarter of launch, 100 prescribers of the drug. So I think that this is obviously a question of you know, are the patients out there, they're well identified. And the question is going to be, you know, does olutasidenib offer an advantage over other therapies that might be used in this relapsed/refractory space, but we plan to differentiate it as best we can.

Thank you.

Thank you,

Thank you. Our next question comes from Yigal Nochomovitz with Citi. Please proceed with your question.

This is Carly on for Yigal. Thank you for taking my question. We have one for Dr. Cortes. Can you talk about how you think the efficacy and safety of olutasidenib compared to ivosidenib. And I guess assuming Lipsitz [ph] approved, how do you see it sort of being used alongside ivosidenib? Thanks.

Dr. Cortes, if you would. Hello? Dr. Cortes?

Can you hear me?

Yes, there you go. Yes, there you go.

Sorry. I was saying that you know, certainly, ivosidenib it's a very good drug, and we've been fortunate to have it for some time. And also, we need to highlight the fact that or acknowledge the fact that, it's difficult to compare when you're looking at two different studies. But if we look at the characteristics of the studies, which are essentially very similarly conducted in a similar patient population. I think that there is many reasons to believe why that olutasidenib compares favorably to ivosidenib. Number one, in terms of the patient population that was in the study. The two are refractory relapse acute myeloid leukemia, but the characteristics of the patients, they are a little bit older in the olutasidenib study. They are a little bit more difficult to treat. For example, the - I mentioned these fully refractory patients. They are – or the relapse patients there were very few patients that had relapsed within 12 months, which is I mentioned the harder patient population, they were less than 10%. Here, we have a third of the patients were like that. So many of the features are equal or worse with the olutasidenib. So we're starting with a worse – with a more difficult patient population. And yet, the overall response rate looks similar, if not better. The overall - the response, the CR plus CRh was 30% with ivosidenib, it's 33% here. But most importantly, the CR rate which was 21% with ivosidenib is 30% with olutasidenib. The duration of remission, which was about eight months with ivosidenib, it's 13.8 months with olutasidenib. So there's differences between the studies. And again, you cannot make too much, but every item points to some benefit compared to what we have with ivosidenib. The QTC prolongation, very uncommon with olutasidenib, which is also very, very important, not that it's that common with ivosidenib, but it is more than we see with olutasidenib. So overall, I feel very good about the potential of these drugs because it is drug because it adds, it has many aspects that seem to suggest further improvement over what we already have with ivosidenib. So I think that I would - certainly, if it was available today, I would use it quite a bit.

Okay. Great. That's very, very helpful. And then we just had a question for Rigel as well. You highlighted the synergies with the existing ITP sales force. Are you expecting to add sales reps in order to support the AML launch? And I guess just curious how much we could expect OpEx to ramp as we go into 2023? Thanks so much.

Thanks, Carly. I'll ask Dave to answer that question and then Dean, in terms of the OpEx piece of it. Dave?

Yeah, Carly, great question. And actually, we're not going to be expanding our sales force at all for this. Because you know, ITP, we have – its a much bigger patient population treated across the community. So we've got significant coverage out there with our current team. And so what we now have to do obviously, and by the way, in the relapsed/refractory setting with an oral therapy. This can be used in the community and patients are being treated in the community. So that will be good. But we'll additionally have to pick up leukemia treaters in institutions, which we're already calling on. But the answer is no additions to our sales force. I think they've got quite the capacity and after announcing this today, I'm pretty sure I could say without any fear of error, they're going to be tremendously excited to have something else in their bag. So that to answer to the question. And that's exactly why when we look at drug like olutasidenib. We think it fits perfectly into our bag. We're seeing hematologists-oncologists community. We can – we’re in the institutions where leukemia treaters are, and we can get spread the word rapidly.

And Carly, with respect to operating expense, we expect limited clinical spend. So Dave described the significant leverage on the commercial side. So limited clinical spend. I'd just remind you also with respect to our just overall operating expense. As we roll off, and we've just completed our Phase 3 study in AIHA, we're wrapping up the Phase 3 study in COVID. We expect to see some leverage, some savings into the future on clinical spend there, too. So that's a bit of feedback on olutasidenib impact on operating expense

Okay.

Thank you, Carly.

Thank you. Our next question is from Joe Pantginis with H.C. Wainwright. Please proceed with your question.

Hey, everybody. Good afternoon. Thanks for taking the question and interesting transaction, and thanks for the details. So first, for Dr. Cortes, I guess when you were talking about the slides regarding the AE profile, physicians such as yourself and at centers of excellence, you said, obviously, these are very manageable toxicity profiles. When you look at things such as the liver elevation and even things like the differentiation syndrome, how is the broader physician community in AML equipped to be able to treat these AEs?

Thank you. I think that by now, we are very well equipped. Liver toxicity is something that general oncology is with many other drugs that we used for solid tumors and other things and even higher incidences and severity than these – is what we see here. One other area that I manage a lot of patients is CML and some of the drugs that we use in CML have higher incidences of these things, and yet, liver toxicity specifically. And I think physicians manage that well. The differentiation syndrome, it's a little bit more unique, not something that we've seen with many other cancer therapies. But number one, it's not that - that's common, fortunately with olutasidenib. And I think that little by little, they have become much more aware of this and they can manage well. I've seen them manage with some of the other drugs that we use in these hematologic malignancies. And they become much more aware and alert than when we started seeing these things initially with an IDH2 inhibitor, which was the first one that it was approved, that was a bit more of a surprise even for us when we started developing the drugs. But then over time, I think they've become very familiar and able to manage these and if not manage themselves at least call for help. So I feel comfortable with how they will be able to manage olutasidenib in the clinic.

Thank you for that very much. And then two TAVALISSE questions for the company, please. Regarding wAIHA, are you able to - I know it's ahead of your FDA interactions in the fall that you mentioned. But are you able to give us any additional information or TEAE [ph] that matter regarding additional analysis that you've been conducting?

Yeah. Joe, thanks for that question. We've done a great deal of analysis on the data since we announced it, and we've worked hard on that. And - but at this point, what we prefer to do is to share that with FDA first before sharing you more broadly. That would be the appropriate step we view as the next step to do and have those discussions and after that interaction be able to report to you and the investor community, what FDA feedback is on that based on that analysis, rather than sharing an additional analysis and have the FDA not view that favorably as a result. So the timing is - it's probably not that far out, by the way. We hope to meet with the FDA in the fall. And after that, we would have some feedback from them and be able to share more.

No, totally fair. And then just quickly, I wanted to see if - how things are being maintained or improving regarding the current refill rate based on prior quarters, you've been hovering around the mid-50s?

Dave, do you want to comment on the persistency?

Yeah. Persistency hasn't changed. We've - it takes a long time to move that curve. Obviously, we've been adding new patients. It's too early to assess whether those patients have longer persistency. But for right now, we're maintaining in the mid-50s.

Great. Thanks, guys.

Thank you, Joe.

Thank you. Our next question comes from Gary Nachman with BMO Capital Markets. Please proceed with your question.

Hi, good afternoon. And congrats on the deal. First for Dr. Cortes, where do you see the most opportunity in additional indications for olutasidenib going forward? In particular, how important will combination therapy will be over time? What's the timing of that data? And at what point will physicians start to experiment with that? And how many more patients are out there beyond the 1,000 that could be good candidates over time?

Yes, thank you. First, in terms of the opportunity, we're next, definitely frontline. I think this is a drug that - of course, you start starting it in refractory relapse as the nature of drug development in AML, but it has a lot of potential for frontline, both as a single agent and in combination because there's patients where you're aiming for different things. So for very unfit patients who are not able to take combinations where you don't - when you want to minimize myelosuppression all these things. Even though I mentioned myelosuppression is the most common, this is far less than you would see with any chemotherapy. So far less than you would see with, for example, [indiscernible] for example, which is so mylosuppressive. So single agent could be very good for some of these patients. But a combination then would be a very valuable addition for the patients where you're aiming for a little bit more responses, deeper responses and so on. So that definitely would be a trajectory to follow. I also like the - I went faster the development, but there was one of the arms, which is for patients that have what we call measurable residual disease, or MRD. So these are patients that have achieved the remission, but they still have - you can find by these sensitive tests detectable DCs. And this is very well suited for that purpose because it's a - it's an oral agent. You would use it as single agent by itself. You don't have to worry about differentiation syndrome in that concept. So it is a very well, very - it fits very well for that purpose. Both after some other sort of chemotherapy or after a stem cell [ph] transplant, if a patient that relapse and you gave them whatever this drug or something else and then they went to a transplant, maintenance of the transplant usually becomes very valuable, if you have something that's effective, that you see that safe, et cetera. So I think that those are areas, some of the areas where it would it well. Now can it grow more than those 1,000 patients? Yes, I think it can. Because number one, if you move it upfront. Number two, I think that as we have more of these treatment options that physicians identified as well tolerated, effective, et cetera, the testing for the mutation starts picking up. And although a lot of the patients are being assessed for mutations nowadays, it's not 100%. It can be a lot better than it is now. So I think that physicians will start looking more and more for these mutations because they know that it could be a big difference for the patients in terms of the treatment strategies that they could use.

Okay. Great. That's very helpful. And then one for the company. I'm curious how competitive was the process for this drug? How did you evaluate the economics for the deal relative to the overall opportunity? I mean if you could try and quantify that for us at a high level, I think that would be helpful. And do you have capacity to do more deals in the hem/onc space and get the full synergies like you're getting with this transaction? And then just comment on the IP for the drug. That would be helpful as well. Thank you.

Sure. Dolly, why don't you comment on the IP, I'll answer the other questions.

Sure. On the composition of matter without any extensions, it is protected through September 2035. And then there's another - a number of very useful methods of treatment, as well as certain forms of the compound as well that have protection through 2039.

Thank you, Dolly. We've been engaged with our colleagues in Forma [ph] for a bid on this drug. We looked at this and we thought it was a very attractive molecule with compelling data that could make it the leading agent in this category in AML. And so for that reason, we were very attracted to it. It is a constrained product. It's not a $1 billion product by any means, but it's a very exciting product for a company like Rigel. In particular, our franchise that we're building in hem/onc with that foundation being ITP with TAVALISSE. This is a perfect add-on molecule to that. And we have a commercial organization in place, boots on the ground now that can deliver value to this asset. And so it made it an attractive proposition for our colleagues at Forma as well, I believe. And as a result, we found a way to mitigate some of the risks, minimize some of the payments upfront for us. We're particularly sensitive in the short term and allow them to recapture some of the value of the tremendous work they did in filing the NDA and prosecuting that NDA with FDA to this point. So I think the economics makes sense as well for us. They're commensurate with that. There's opportunities here beyond relapsed/refractory AML, IDH positive AML. And as Dr. Cortes said, in early therapy, either as a single agent or combo therapy, there's opportunities in glioma as well where some work has already been done. So there's other things we could explore here. So it offers opportunities even beyond the initial potential indication that where the PDUFA date is in February. Can we do more? Absolutely, we can do more here. Once we've laid a good foundation and we've leveraged that, I think we'll be in a position to continue to build in this area. And this sets a precedent for what we might do going forward. No promises and no promises on timing, of course, but it's a pretty exciting next step for us as a company.

Okay. Great. Thank you.

Thank you. Our next question comes from Kristen Kluska with Cantor Fitzgerald. Please proceed with your question.

Good afternoon. This is Rick on for Kristen. Thank you for taking our questions. We have two for you. On the topic of potential sublicensing around the AML opportunity, are you able to give any color on what Rigel could look for in a potential partner for bringing olutasidenib forward ex-U.S.?

Sure. I can take that. We have rights to do ex-U.S. sublicenses. And there's a very good opportunity. And obviously, this disease is not solely a U.S. issue. It's a very severe disease globally. And so we will look to, in the future, do deals with partners outside of the U.S. There may be an additional trial required in some territories, and that would be part of the discussion with those parties. We do know that there were investigators that participated in the trials, the registrational trial in Europe that are very enthusiastic about, we're continuing to work with this molecule. And so we'll - that will be part of the discussion as well. But that's an exciting facet to this agent that I think allows us to do that a bit further. And frankly, the additional resources to its further development benefiting us here in the U.S. tremendously from a commercial perspective.

Understood. Okay. And one more. After completing COVID-19 enrollment, are you able to say thing about any potential effects that the recent increase in transmission rate across the U.S. has had or had had in the last stretch of the enrolment? Thanks.

I'll ask Wolfgang to maybe comment on that.

Yeah. No, we did not really see that reflected in hospitalizations at the sites that we were working with in the – in the countries that we were working with. So while it's possible, there might be some additional hospitalizations coming. We feel comfortable with the sample size that we have. And with the change primary endpoint, we have a little bit more sensitivity than with the original primary endpoint and therefore, we decided to stop enrollment at 280.

Thank you.

Thank you, Rick.

Thank you. Our next question is from Kalpit Patel with B. Riley Securities. Please proceed with your question.

Hey, good afternoon. Congrats on the deal with Forma. And thanks for taking the questions. Starting out with Dr. Cortes, I guess when you compare the 2 IDH1 inhibitors, has anything stick out from a tolerability perspective that might position one molecule favorably to the other? I know you talked about occupancy differences, but curious to hear your perspective on safety?

Yes. I think that there are some differentiators that I like for - from the perspective of the safety profile. The incidence of QTc prolongation is very low. And that is a big asset, in particular because you don't have to be doing ECG’s and these things, if they have been outpatient, it's hard to get them. As I mentioned, there's only one patient in the whole study, so that's less than 1%, whereas in here with ivosidenib, it was reported in almost 8% of patients. And I'm talking about the Grade 3, the most severe conditions. So 8% is not a huge percentage, but it is definitely a number that starts making you pay attention because it can be severe. So that is one. And the - I think that the liver toxicity doesn't worry me. I think it is something that's highly manageable in for - again, for the general oncologists, especially because most of these can be managed because we just transcend treatment interruptions, sometimes those adjustments. And as I mentioned, most of the patients can really continue being treated. So I think that the safety profile is equal or better for - with olutasidenib compared to the ivosidenib and I really – I manage many of these patients that I told you about, and it's been very easy to manage. We've done combination. We've reported some of those early results in combinations in some of the meetings and the combination with HAS [PH] because of the good safety profile, it's also easy to combine with other drugs, which is also a great value.

Okay. And Dr. Cortes if the data are available from respective trials of these 2 IDH inhibitors, do you see any differences in the number of patients that are eligible to receive a transplant or actually go on and receive a transplant after?

Well, one of the criteria that you need for getting a patient to transplant is to get them to at the very least a partial response. And then, of course, all the way up to a complete remission. So for that matter, I mentioned that the overall response rate is 46% when you include all of these responses. So all of these patients could potentially be eligible for transplant. Then, of course, comes the issue of age, comorbidities, donors, other factors and many patients drop out because of these conditions. But at least from the perspective of the disease and the response that you get with the drug, that's almost half of the patients would become potentially eligible for a transplant.

And then one question for the company, sort of building on one of the previous questions. Since TIBSOVO moved I think so far in that early chemo eligible patient population in the frontline setting. Does that approval in the frontline impact your development efforts to moving your IDH inhibitor earlier on or even your commercialization efforts in the late line setting for this new asset?

Dave, why don't you address our commercial focus and now and maybe in the future and maybe Wolfgang and I can comment on future development.

Yeah. I think for us, that was another thing, obviously, that attracted us to this opportunity. IDH1 is now well proven in the newly diagnosed patient with Category 1 evidence in the NCCN guidelines. So I think obviously that would be something that, as I said earlier, would be good if we could move into the earlier line setting. But for right now, the relapse setting for us is a perfect entry. It's where other targeted agents have started. And I think that's where the most need is. And so we'll do that. Obviously, we don't have any comparative trials to another IDH1 inhibitor. And so we can only discuss our data. But at the end of the day, I think as you've heard, I think clinicians might see some differentiating pieces here that could allow them to use it in different settings in AML. But we're going to wait until we see when the label is and then we'll be - if it is approved, and if it is made available at that time, we will pursue that with vigor.

Yes. This is Wolfgang. Just to add to that. As you've heard from Dr. Cortes, the data in the refractory relapsing population looks compelling, right, with high response rates and with a long duration of disease in a manageable safety profile. So even if others have studies going on in earlier patients or frontline patients doctors usually follow the data. And if they believe there's something promising, I'm optimistic that we could engage them in discussions around earlier use.

Okay. Thank you very much.

Thank you.

Thank you. There are no further questions at this time. I would like to turn the floor back over to Mr. Raul Rodriguez for any closing comments.

Well, thank you for your questions and for the position [ph] that we made in terms of your time. I appreciate that. It's an exciting quarter. We accomplished some really important milestones this past quarter. Regaining momentum and growth in ITP sales, I think that is foundational to the company in terms of the hem/onc business. Overlay that in - on top of that, this in-license providing leverage with an existing organization. And we're incredibly excited about those two events this quarter, and I think it bodes really well for this year and into next. And then progress on some of our pipeline programs with fostamatinib, with FDA coming soon, with COVID data coming soon and advancements into patients with our earlier two programs, are two things we're very excited about. So thank you for your questions, and look forward to providing you more information as it appropriate. Take care.

This concludes today's conference. You may disconnect your lines at this time. Thank you for your participation.