Deciphera Pharmaceuticals, Inc. (DCPH) Q1 2021 Earnings Call Transcript

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Deciphera Pharmaceuticals, Inc. (DCPH -0.61%)
Q1 2021 Earnings Call
May 4, 2021, 4:30 p.m. ET

Contents:

• Prepared Remarks
• Questions and Answers
• Call Participants

Prepared Remarks:

Operator

Good afternoon, everyone and welcome to Deciphera Pharmaceuticals First Quarter 2021 Financial Results Conference call. Today's call is being recorded.

At this time, I would like to hand the conference over to Jen Robinson, Vice President of Investor Relations. You may begin.

Jen Robinson -- Vice President of Investor Relations

Thank you, Tolanda. Welcome and thank you for joining us today to discuss Deciphera's first quarter 2021 financial results. I'm Jen Robinson, Vice President, Investor Relations at Deciphera. With me this afternoon to discuss the financial results and provide a general corporate update are Steve Hoerter, President and Chief Executive Officer; Dan Martin, Chief Commercial Officer; Matt Sherman, Chief Medical Officer; and Tucker Kelly, Chief Financial Officer.

Before we begin, I would like to remind you that any statements we make on this call that are not historical facts are forward-looking statements, reflecting the current beliefs and expectations of management, made pursuant to the Safe Harbor provisions of the Private Securities Litigation Reform Act of 1995. Examples of forward-looking statements made during this conference call include our expectations for our preclinical and clinical programs, our commercialization of QINLOCK and 2021 guidance. Forward-looking statements made on this call involve substantial risks and uncertainties, that could cause actual results to differ materially from those expressed or implied by the forward-looking statements, and we cannot assure you that our expectations will be achieved. Such risks and uncertainties include those set forth in our most recent quarterly report on Form 10-Q, as well as our other SEC filings. We assume no obligation to update or revise any forward-looking statements. Following this call, a replay will be available on the Company's website www.deciphera.com.

I will now turn the call over to Steve Hoerter, President and Chief Executive Officer of Deciphera. Steve?

Steven Hoerter -- President & Chief Executive Officer

Thank you, Jen. It's been an exciting start to the year for Deciphera, as we build upon all that we accomplished in 2020 and execute on our strategic priorities across the portfolio for 2021. We continue to make great progress against the three areas of focus for QINLOCK this year, successfully launching QINLOCK in the US, expanding the geographic reach of QINLOCK by seeking regulatory approvals around the world, and moving QINLOCK into earlier lines of therapy in GIST.

Our successful launch of QINLOCK in the US demonstrates the significant unmet medical need in fourth-line GIST and the potential for QINLOCK to offer a meaningful difference for patients in this setting. In a few minutes, Dan Martin, our Chief Commercial Officer will outline our success in quickly establishing QINLOCK as the standard of care in its approved indication. Our rapid penetration of this market and the very positive perceptions of QINLOCK by just treaters, create a solid foundation for our potential future expansion into the second-line setting.

In the first quarter, we made important progress in our goal to expand the geographic reach of QINLOCK. Our partner in Greater China, the Zai Lab, received approval for QINLOCK from both the China National Medical Products Administration and the Hong Kong Department of Health. An estimated 30,000 new patients were diagnosed with GIST in China each year, and we look forward to supporting Zai as they launch QINLOCK in China later this quarter.

We expect to receive approval for QINLOCK from the European Medicines Agency in the fourth quarter of this year. As we await action from the EMA, we are actively laying the groundwork for our commercial organization in Europe and building an experienced and focused team that will allow us to quickly deliver QINLOCK to patients in key markets once approved. As the first drug specifically designed to treat GIST, we believe QINLOCK has the potential to fundamentally alter the treatment of this disease. One of the key elements of our strategy to expand the use of QINLOCK in the earlier lines of treatment is our ongoing Phase 3 study INTRIGUE, in the second-line setting.

We expect to announce top line results for INTRIGUE in the fourth quarter of this year and beyond the INTRIGUE study, we are pursuing additional opportunities to benefit patients with GIST by evaluating the use of QINLOCK as a backbone of the treatment combination that seeks to address one of the potential mechanisms of resistance to kinase inhibition, reactivation of the MAP kinase pathway. Matt Sherman, our Chief Medical Officer, will discuss in more detail later in the call, our plan to initiate later this year a Phase 1b/2 study of QINLOCK in combination with binimetinib, an approved MEK inhibitor.

Finally, we remain very excited about our expanding pipeline of KIT inhibitors beyond QINLOCK. Throughout 2021, we expect to have significant clinical and regulatory updates that we believe have the potential to create significant value for shareholders, as we continue to deliver on our mission of discovering, developing and commercializing new medicines for patients with cancer.

I'll now turn the call over to Dan Martin, our Chief Commercial Officer, to discuss the US QINLOCK commercial results from Q1. Dan?

Daniel Martin -- Chief Commercial Officer

Thank you, Steve. Good afternoon. Today, I'm pleased to report the results of our third full quarter of QINLOCK sales and to provide additional color regarding our expectations as we look ahead. We continue to be very pleased with the QINLOCK launch, including a rapid penetration of the fourth-line opportunity and the overwhelmingly positive response we received from just treaters. In Q1, we achieved $20 million in total net product revenue, including $19.3 million in the US, bringing total launch to date US net product revenue to $57.3 million. As we have shared previously, prior to launch, our goals were to rapidly establish QINLOCK as the standard of care in our initial fourth-line indication, while building clinical experience and positive product perceptions among the broad prescriber base, in advance of a potential launch into the larger second-line opportunity.

Thanks to the continuing efforts of our cross-functional teams to navigate the unprecedented challenges of the COVID-19 pandemic, we have continued to make excellent progress toward these goals. Our recent market research indicates that commercial execution was again a strong point in Q1. Despite the continuing need to operate largely through a virtual model, our sales and marketing teams maintained high levels of prescriber reach, frequency and share of voice and grew our prescriber base to over 400 prescribers from more than 350 institutions since launch.

Despite having limited opportunities for in-person meetings, our sales team has established an excellent reputation among just treating physicians. In a recent blinded survey, just prescribers cited the Deciphera sales team as best-in-class among companies in the GIST market, and ranked the team first across every performance metric evaluated. Our market research also shows that this continued strong execution has had a clear impact. QINLOCK awareness and familiarity among prescribers treating fourth-line GIST remained extremely high and just treaters again reported very positive perceptions of QINLOCK's clinical attributes. In a recent survey, nearly 90% of all just treaters and 100% of physicians who have prescribed QINLOCK, agreed that QINLOCK is the standard of care in fourth-line GIST.

Further, among physicians who initiated a fourth-line GIST treatment within the prior 90 days, nearly all had prescribed QINLOCK. In addition to the strong performance of our sales and marketing teams, our market access team continued to deliver broad patient access to QINLOCK in Q1. Payer coverage for QINLOCK remained very positive with policies aligned to our FDA label. During the quarter, the percentage of patients that received free drug under our Patient Assistance Program or PAP, was at the low end of our estimated range of 20% to 30%. Prior to launch, data from the INVICTUS study gave us confidence that QINLOCK has the potential to transform the treatment of advanced GIST.

Now, early data from our fourth-line launch is providing insight into how QINLOCK is benefiting patients in the real world setting. Though it's still early days, and the data are still maturing, the real world persistency that we see for patients who have received QINLOCK since launch, is similar to what we saw in the INVICTUS study, consistent with our prelaunch expectations. Ultimately, based on data from our clinical trials, we would expect the average time on therapy to be somewhat longer than the median, due to the impact of long-responders. However, it will take time for this data to mature and it's still too early to know how this trend will play out in the real world setting.

In terms of broader market dynamics, we may now be seeing more clearly, the impact that the pandemic is having in oncology and specifically in GIST. Data from IQVIA show that the pandemic has had a persistent negative impact on oncology diagnosis visit since Q2 of last year and IQVIA projects that this impact is likely to continue in the coming months. Further, a recent analysis of claims data for earlier-line GIST patients, showed a decline in new patient volume over the past year of approximately 10%. This trend is something that we will continue to assess as it could impact the volume of patients progressing to fourth-line treatment this year.

These data are consistent with our discussions with GIST thought leaders, who indicate that patient volume and referral patterns have been inconsistent during the pandemic. Given QINLOCK's rapid penetration of the fourth-line opportunity, as well as the uncertain impact that the pandemic may continue to have in the near term, we expect the opportunity for growth to be limited until we are able to expand into the second-line setting, pending positive data from INTRIGUE and subsequent approval. As we've discussed, we believe the opportunity for QINLOCK is substantially larger in the second-line compared to our initial fourth-line indication.

This is driven by a larger estimated incident patient population, as well as the fact that patients may experience increased clinical benefit and longer time on therapy, when they receive QINLOCK earlier in their course of disease. As we have shared previously, we believe the distribution of patients in the second-line is weighted more heavily toward the community setting, when compared to fourth-line patients. With this in mind, we are extremely pleased to see that while academic prescribers made up the majority of our earliest adopters, we have also made tremendous progress in the community.

In Q1, we estimate that more than half of QINLOCK-treated patients and 70% of new prescribers, came from the community setting. We believe our diverse prescriber base across both academic and community settings and the awareness and positive product perceptions we have established among GIST treaters more broadly, positions us extremely well for a potential future second-line launch. Moving forward, our focus in the US will continue to be on optimizing our fourth-line business, while at the same time initiating our launch preparations for a potential approval in the second-line.

QINLOCK has already found -- QINLOCK has already had a profound impact on the treatment of advanced GIST and we are extremely motivated by the potential opportunity to help patients even earlier in their course of disease, when they may benefit most.

I will now turn the call over to Matt Sherman to discuss the progress of our clinical programs. Matt?

Matthew Sherman -- Chief Medical Officer

Thank you, Dan. As Steve mentioned, we remain focused on demonstrating QINLOCK's profile as a best-in-class broad-spectrum KIT inhibitor in our ongoing Phase 3 INTRIGUE study comparing QINLOCK to sunitinib in patients with second-line GIST. Based on the progress of the INTRIGUE study, we expect to announce top line data in the fourth quarter of this year. We remain very optimistic about the potential for QINLOCK to demonstrate superiority over sunitinib, basis with strong results of the Phase 1 study, where QINLOCK showed a median progression-free survival of 10.7 months in second-line patients.

We believe, that to demonstrate clinically meaningful benefit in INTRIGUE, we will need to show a 2 to 3 month increase in PFS, relative to the expected PFS for the submitted farm was approximately six months. Finally, we believe that the exceptional results of the Phase 3 INVICTUS study showing a median PFS of 6.3 months in fourth-line plus GIST patients receiving QINLOCK strongly supports the likelihood of success in INTRIGUE.

We are excited to announce today our plans to initiate a Phase 1b/2 study of QINLOCK in combination with Binimetinib and improve the MEK inhibitor, to address one of the potential resistance mechanisms in GIST. Despite the benefit that QINLOCK and other approved KIT inhibitors provide for many GIST patients, resistance remains a significant challenge. We have long thought about how dual pathway inhibition may increase responses in GIST patients.

The goal of the new study is to see whether we can deepen the ample long initial responses by combining broad KIT inhibition from QINLOCK with inhibition of the MAP kinase pathway using a MEK inhibitor. First-line in MAP has proven to be effective in stabilizing disease progression in most GIST patients, but less than 10% of patients experience complete regression. GIST often becomes a MAP resistant after acquiring secondary mutations, most often in care or the MAP kinase pathway can be reactivated increasing KIT expression.

These patients experience progressive disease that no longer responds to MAP with treatment. Our Phase 1b/2 clinical study is supported by exciting preclinical data that was recently published online in molecular cancer therapeutics, as well as preclinical data presented at the EORTC-NCI-AACR meeting in 2018, showing that treatment with QINLOCK in combination with MEK inhibitors, effectively induced and enhanced apoptotic responses and prevented growth of resistant colonies in GIST cell lines.

In addition, QINLOCK demonstrated superior efficacy to imatinib in combination with MEK inhibitors. The QINLOCK MEK inhibitor combination was better than the imatinib MEK inhibitor combination and inhibiting cell growth even after removal of drug. One major advantage of using QINLOCK as a combination partner with a MEK inhibitor over imatinib, is that QINLOCK treatment did not result in the generation of resistance mutations in preclinical studies. We expect to initiate a Phase 1b/2 open label study in the coming months to evaluate the safety, efficacy and pharmacokinetic Sipkin in combination with Binimetinib in patients with GIST, well progressed on at least imatinib or are intolerant to imatinib.

The study will consist of a dose escalation phase and an expansion phase. The dose escalation phase will follow a 3 plus 3 study design, and will enroll patients with advanced GIST who have not been previously treated with QINLOCK. The expansion phase is a single cohort study to evaluate the efficacy and safety of the recommended Phase 2 dose of the combination in a cohort of patients who have progressed on or are intolerant to single agent imatinib.

We are focused on exploring the full potential of what we believe is QINLOCK's best-in-class KIT profile, to benefit patients with GIST and believe that this combination therapy could give GIST patients a new treatment option that provides enhanced clinical benefit compared to KIT inhibition alone. In addition to our clinical activities, we are executing well on our robust publication and presentation strategy. There have been a number of recent publications highlighting the use of QINLOCK in a GIST treatment landscape. Building on the intra-patient dose escalation data we presented last year, from the Phase 1 study of QINLOCK, I'm pleased to announce that we plan to present intra-patient dose escalation data from the Phase 3 INVICTUS study, in an e-poster at the American Society of Clinical Oncology or ASCO Annual Meeting in June.

We are also making great progress in our other ongoing pipeline programs. Let me start with Rebastinib, since we will be providing updated data for this program in ASCO this year. Rebastinib is our potential first-in-class selective inhibitor of the TIE2 kinase. We presented highly encouraging infant tumor activity for both the endometrial cancer and platinum-resistant ovarian cancer cohorts from the Phase 1b/2 study in combination with paclitaxel last year.

Focusing on the endometrial cancer cohort, we have completed our target enrollment of 33 patients in Part 2 study and we are excited to present updated data from this cohort at the upcoming ASCO Annual Meeting. We previously reported an encouraging objective response rate in this heavily pretreated cohort, with a median of four prior lines of treatment and further follow-up will now enable us to present progression-free survival for these patients.

In regard to the treatment landscape for endometrial cancer, there are limited options that the paclitaxel and carboplatin in first-line setting and Imatinib and pembrolizumab in the second-line setting. The expected activity for paclitaxel retreatment to later lines of endometrial cancer patients, is a response rate of 10% to 20% and a PFS of 3 to 4 months. This was recently reinforced by the data presented at the Society of Gynecologic Oncology or SGO, from KEYNOTE 775, the Phase 3 study in patients with advanced endometrial cancer, who progressed after only one prior regimen, which compared with Imatinib and pembrolizumab to physician's choice of chemotherapy of either weekly paclitaxel or doxorubicin.

The chemotherapy arm showed the confirmed response rate of 15% and a PFS of 3.8 months, which is consistent with our expectations with a limited activity of single agent paclitaxel retreatment in endometrial cancer. In addition, we remain on track to present updated results from the ongoing Phase 1/2 study with Rebastinib in combination with paclitaxel in the platinum-resistant ovarian cancer cohort in the third quarter of the year.

We are focused on driving this program forward and as efficiently as possible and we expect to finalize potential pivotal development plan for Rebastinib in combination with paclitaxel in the coming months. The other two programs in our pipelines is Vimseltinib, our potential best-in-class inhibitor of CSF1R in development for the treatment of tenosynovial giant cell tumor and DCC-3116, our potential first-in-class ULK kinase inhibitor in development for the treatment of mutant RAS or RAF cancers, remain on track.

For Vimseltinib this year, we expect to present updated data from the ongoing Phase 1/2 study in patients with TGCT in the third quarter and finalize the pivotal development plan for this program in the second half. So, DCC-3116, we are excited to initiate the first in human study this quarter. We look forward to the continued progress of these programs, each of which has the potential to make a meaningful difference in the lives of patients and fulfill current unmet medical needs.

I will now turn the call over to Tucker Kelly, our Chief Financial Officer, to review the financial results. Tucker?

Tucker Kelly -- Executive Vice President & Chief Financial Officer

Thanks, Matt. I'd like to review the highlights from our first quarter financial results. Total revenue for the first quarter was $25.2 million, which includes $20 million in net product revenue of QINLOCK, $19.3 million of which was from sales in the US. The gross to net adjusted in the first quarter was in line with our annualized estimate of approximately 15%. Collaboration revenue of $5.2 million included a $5 million development milestone under our license agreement with Zai Lab, triggered by the regulatory approval of QINLOCK in China in March.

Once Zai begins to commercialize QINLOCK in Greater China, we will receive royalties based on annual net sales levels that range from the low-to-high teens. In addition, we are eligible for up to $135 million in commercial milestones based on achievement of certain annual sales of QINLOCK in Greater China, as well as additional development milestones.

Cost of sales for the three months ended March 31st, 2021 was immaterial, as the majority of the manufacturing costs related to QINLOCK sales were incurred prior to FDA approval and thus were recorded as R&D expense. As we have said previously, we expect the cost of sales will remain immaterial through at least this year and would not expect cost of sales to be significant until the initial pre-launch inventory is depleted and additional inventory is manufactured and sold.

Total operating expenses were $86.4 million in the first quarter of 2021, compared to total operating expenses of $75.3 million in the same period in 2020. Research and development expenses in the first quarter were $55.7 million compared to $51.4 million in the same period of 2020. And selling, general and administrative expenses in the first quarter were $30.7 million compared to $23.9 million in the same period last year. We continue to expect that our operating expenses will increase modestly this year, as we invest in the development of our clinical pipeline, execute on the commercial launch of QINLOCK in the US and prepare for potential commercial launch in Europe. We ended the first quarter in a strong financial position and remain well capitalized with cash, cash equivalents and marketable securities of approximately $502 million, which we now expect will be sufficient to fund our operations into the first half of 2023.

And with that, I'll now turn the call back over to Steve.

Steven Hoerter -- President & Chief Executive Officer

Thanks, Tucker. I'm proud of the work our team has done in the first quarter of this year to sustain the momentum we built in 2020. As we continue to establish QINLOCK as the standard of care for fourth-line GIST, we are excited to expand its reach to patients and prescribers around the world, with both the recent approval in China and are pending approval in Europe later this year. As we realize the transformational potential QINLOCK has for patients with fourth-line GIST, we look forward to announcing top line results from INTRIGUE in Q4 and unlocking the potential for QINLOCK in the second-line. 2021 is also expected to bring significant updates across the balance of our pipeline, including the dosing of our first patient in the Phase 1 study of DCC-3116, as well as new data and potential pivotal development plans for both Vimseltinib and Rebastinib.

With that operator, I'd like to open the call for Q&A.

Questions and Answers:

Operator

Speaker O-Operator

Thank you. [Operator Instructions] Our first question comes from the line of Jessica Fye with JPMorgan. Your line is open.

Daniel Wolle -- JPMorgan -- Analyst

Hi, this is Daniel for Jessica. Thanks for taking our question. First question is, you have stated in your prepared remark that it will take time for data on duration of treatment to mature. With the product now in the market for almost a year, when do you expect to have better insight on average time of fund therapy. And when you talk about persistency similar to INVICTUS, can you elaborate for us and provide some more detail?

Steven Hoerter -- President & Chief Executive Officer

Yes, Daniel. Thanks for your question. It's a good set of questions. Dan, would you like to take this?

Daniel Martin -- Chief Commercial Officer

Sure, absolutely. So, with respect to persistency looking similar to what we saw in INVICTUS, when we -- not the persistency curve that's emerging for patients who received QINLOCK since launch, it looks quite similar to the Kaplan-Meier curve for PFS from INVICTUS. So, we think that's a sort of a good guide for kind of what we're seeing in the persistency data thus far. And then the comment about it will take time to develop, that was more about the average as opposed to sort of percent of patients on therapy at different time points in these early days.

So the average of course will be impacted by a potential long tail, long responders in the persistence curve and given that we're only as you say, about a year into launch, give or take, we're just not there yet. If you think about the clinical data from Phase 1 trial for example, it took multiple years to sort of fully develop those long-responders. So, that was why I said, if we look at the data from clinical trials to date, we would expect the average to be somewhat longer than the median, but it will just take us some time for that data to mature.

Daniel Wolle -- JPMorgan -- Analyst

Got it. And then I know that you've said the next slate of meaningful growth will come from sales in second-line, but should we think about this roughly $20 million quarterly run in the US, as a good run rate to use going forward for the US fourth-line opportunity or is there a potential for that to change as the impact of COVID lessens going forward?

Steven Hoerter -- President & Chief Executive Officer

Yes. Daniel it's Steve. It's a good question and I think as Dan mentioned in his prepared remarks, we do see data both in claims as well as from third-party providers, that suggests that there has been and is an ongoing impact from the pandemic, and I think it's just inherently uncertain as to how that unfolds for us with QINLOCK during the course of this year. As Dan mentioned, our view is that, we'll see limited growth as a result of the contacts you're going forward as we get to the readout of INTRIGUE in the second-line and a potential approval that will come subsequent to that.

Daniel Wolle -- JPMorgan -- Analyst

Okay. And last one, the PR states that the cost of sales will not be significant until the initial pre-launch inventory is depleted and additional inventory is manufactured and sold. Do you have an estimate of when you exhaust that inventory?

Tucker Kelly -- Executive Vice President & Chief Financial Officer

So, we don't, it's Tucker, other than that, we don't expect it to be material this year and that as we move forward, we'll be able provide updated guidance on what the cause might look like in terms of when we'll be selling inventory that was not capitalized at the time of approval.

Daniel Wolle -- JPMorgan -- Analyst

Great. Again, thank you very much for taking my questions.

Operator

Thank you. Our next question comes from the line of Chris Raymond with Piper Sandler. Your line is open.

Chris Raymond -- Piper Sandler -- Analyst

Hey, thanks for taking the questions. Just help me understand the math a little bit. I think I heard you guys say that there is more than 400 prescribers this quarter and I think by my math, that's about a 15% prescriber growth quarter-on-quarter. And I remember last quarter you guys mentioned that the percentage of docs that had multiple patients on therapy was still pretty low, and I think I hear what you're saying with respect to COVID, but maybe just if you can maybe, first of all just square that. If you've got a 15% prescriber growth, how does that square with flat quarter-to-quarter revenue?

And maybe can you talk about any sort of dynamics with respect to like free drug or anything like that that might be, also impacting the revenue number. Thanks.

Steven Hoerter -- President & Chief Executive Officer

Yes, thanks for the set of questions, Chris. Dan, would you like to take those?

Daniel Martin -- Chief Commercial Officer

Yes, absolutely. Thanks. Thanks for the question, Chris. Yes. So the key insight here are the key thing to keep in mind, is that, not all prescribers contribute patients each quarter. This is a rare cancer in the fourth-line setting, and so we can see new prescriber growth since launch, but that doesn't mean that every one of those prescribers and therefore every one that's contributing to that 15% growth you mentioned is contributing patients in any given quarter. We've said previously that, especially once you get onto the community setting, physicians may only see a fourth-line GIST patient every 12 to 18 months. So it's just, it's really rare and that's really the driver I think, hopefully that helps square the math a little bit for you.

Chris Raymond -- Piper Sandler -- Analyst

Well, yes, it does. But I guess just the inference, that the fourth-line GIST market opportunity is $80 million. I guess that seems to also sort of raise some questions I guess I'm getting from some investors, of how was -- get that sizably lower I think than the patient numbers that we've gotten. And I know you mentioned COVID but just if you have any sort of sense if patients aren't getting treated, what -- what is happening with these folks? I'm sorry for the kind of dumb question there, but yes.

Daniel Martin -- Chief Commercial Officer

No, it's a good question. So I think a couple of important things to keep in mind. We've shared previously that it's important to use -- support to recognize that when you use a persistency curve, that really reflects the amount of patients on therapy at any given time point. And when you use an average number, you plug that average in, that tends to overestimate the number of active patients in the early days of launch. So I don't know if that is a delta in how you've built your model. But what I can say is that, given all of the data that we've shared previously in this call and in prior calls, we think we've done a great job rapidly penetrating the opportunity. The response from the physicians both academic and community has been overwhelmingly positive and I think it sets up great for the larger opportunity in second-line pending approval.

Chris Raymond -- Piper Sandler -- Analyst

Okay, thank you.

Operator

Thank you. Our next question comes from the line of Eun Yang with Jefferies. Your line is open.

Eun Yang -- Jefferies -- Analyst

Thank you. So, Phases 3 INTRIGUE study patient enrollment was completed at the end of November last year. So, I want to ask you a couple of questions there. One, [indecipherable]. I just, are you still comfortable with your PFS assumption for sunitinib at around six months?

And second question is, I want to ask you if PFS events have been occurring in line with your expectations?

Daniel Martin -- Chief Commercial Officer

Yes, hi, Eun. So, I'd be happy to take those questions. I think with respect to the first question about what we'd expect to see from Sutent, our view of that hasn't changed. As we talked about on prior calls, we would expect based on the pivotal study for Sutent and what their -- which is in the Sutent label, that a PFS of 5.6 months, we would expect to see a PFS in present day -- the present day environment of somewhere in the range of six months and that's very consistent with the feedback that we heard historically and also to this day, from thought leaders.

So we're very comfortable with what we'd expect to see from Sutent and as you know from our Phase 1 experience, and our second-line cohort from the Phase 1, we've seen really compelling data in that cohort, with a median PFS of 10.7 months. And of course you know INVICTUS. So we think the totality of the data -- the clinical data we've generated so far with QINLOCK is very positive and our confidence in the potential for INTRIGUE read a positive study remains unchanged.

In terms of accumulation of events, we haven't comment in terms of what the pace of events we would expect to be. I would just note that when we first designed the study and loaded the information on clinicaltrials.gov, we had expected at that time that -- that we would get to the primary endpoint of the study in June of this year and of course a number of things have changed along the way, in terms of number of subjects in the study and also the environment in which we're operating. But we don't view the refinement of our guidance for Q4 in terms of the top line readout as being really a subset of sort of change.

Eun Yang -- Jefferies -- Analyst

Thank you. And then a question on the Binimetinib combo study. So as you mentioned, in second-line, you are already seeing close to 11 months of PFS. So by adding Binimetinib post Imatinib, considering likely potentially increase the side effects or what are you aiming to achieve? Thank you.

Steven Hoerter -- President & Chief Executive Officer

Yes, thanks, Eun. It's Steve, I'll take that and then Matt please feel free to chime in as well. I mean, we're really excited about the data that we've generated, that now as Matt said in his prepared remarks, has been published, showing the real synergy between QINLOCK and MEK inhibitors, generally. So our goal given the fact that QINLOCK is now established as monotherapy as the standard of care in the fourth-line, we hope and expect that will certainly be the case when INTRIGUE reads out in Q4 of this year, as we move to advance the drug as monotherapy into an earlier line of treatment based on INTRIGUE.

But our goal in this disease with QINLOCK is really to maximize the potential clinical benefit for patients and we think based on the preclinical data we've generated, if we follow that science, that there is a real potential for us to potentially deepen and prolong responses that we see with the combination relative to monotherapy QINLOCK. And we certainly have some indication of the potential for that, based on data that's already been generated. But, Matt, anything else you would add to that commentary in terms of the potential for the MEK combination?

Matthew Sherman -- Chief Medical Officer

Yes. Thanks Eun, for the questions here. And also just to add, I mean, we feel very excited about the combination. Combination therapy in oncology tends to be a very good way of increasing responses and increasing the durability of those responses. And based on the preclinical data that we highlighted today and that's available, we feel that the biological mechanism supports the combination of the mechanism but with -- with QINLOCK. In terms of the safety, we certainly know that QINLOCK has a very good safety profile based on what's in the label as well as what we've heard from investigators. And we'll be starting off by doing a dose escalation study in combination with binimetinib and feel that we'll be able to monitor and manage any adverse events that may occur.

Eun Yang -- Jefferies -- Analyst

So, question is more specifically what additional PFS benefit would be meaningful if you show about close to 11 months of PFS with ripretinib alone in second-line?

Daniel Martin -- Chief Commercial Officer

Yes Eun, I think that put simply, we think there may be an opportunity to continue to raise the bar. So, we're certainly not satisfied with 10.7 months, we'll see the data from INTRIGUE as monotherapy coming up here in Q4, but to the extent there is an opportunity, is not outlined through a combination approach with QINLOCK as really the backbone of that combination to drive better PFS and a longer response for patients, that's certainly something that we're interested in pursuing.

Eun Yang -- Jefferies -- Analyst

Thank you.

Operator

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

Michael Schmidt -- GuggenheimA -- Analyst

Hi guys, thanks for taking my questions. I had a few more on the INTRIGUE study. Just on the refined guidance for data now in the fourth quarter, I guess has there been a change in the event rate relative to your initial expectations or perhaps the censoring rate?

Steven Hoerter -- President & Chief Executive Officer

Yes, Michael, it's Steve. Thanks for the question. We haven't disclosed as you know, the event rate, when we expect the events to -- to fully accrue and the timing for that. But as I said earlier, in response to an earlier question, the refinement to Q4 is certainly within the range of what we guided to previously, this was the second half. So we're just now in a position where we can narrow that down a little bit better, which is the reason that we made the incremental disclosure today.

Michael Schmidt -- GuggenheimA -- Analyst

Perfect, thanks. And then a question we've been getting from investors around how Sutent can perform differently depending on the type of KIT mutations. I think specifically in exon 13/14 mutations where Sutent has been shown to perform relatively well. I guess could you remind us how ripretinib performs in exon 13/14 patients specifically relatively to Sutent and perhaps what percent of second-line GIST patients have exclusively exon 13/14 mutations?

Steven Hoerter -- President & Chief Executive Officer

Yes, thanks for the question, Michael. So I'll start off and then I'll turn it over to Matt. And I think as you know, as we've talked about previously, when we designed this drug, specifically for GIST, the goal was to design a broad spectrum inhibitor and we think we've now very convincingly demonstrated that QINLOCK is in fact a broad spectrum inhibitor, based on the strength of the data from INVICTUS and also the data that we've generated in the Phase 1, and we're looking forward of course, to the report out of INTRIGUE here later this year.

But Matt, what additional color or commentary would you offer in terms of mutational background in the second-line?

Matthew Sherman -- Chief Medical Officer

Yes, I think we could also just point to the very strong results of the INVICTUS study in fourth-line patients and where those are the patients with private characterized side of most have genetic their mutational burden, and that's what we showed in the presentation last year and yet despite that broad heterogeneity of mutations in the forefront just patient population, we have the outstanding results of the benefit of PFS, as well as some the -- the clinical meaningful increase in overall survival. So again just reinforcing the productivity of Ripretinib against multiple KIT mutations.

Michael Schmidt -- GuggenheimA -- Analyst

Okay, thanks. And then just on the Binimetinib combination strategy, is that something that has to be pursued strictly in the post-imatinib setting or is that a combination that could perhaps take on imatinib in first-line GIST down the road?

Steven Hoerter -- President & Chief Executive Officer

Yes, Michael, it's a good question and I think Matt can touch on this as well. But you know as he noted in his prepared remarks, we've seen in the preclinical setting, the potential for the combination of MEK with QINLOCK to be superior to that of imatinib plus the MEK inhibitor. So in efficacy, QINLOCK of course does a much better job than imatinib at preventing additional mutations in KIT from emerging. So, we do think that that combination has potential. Our initial step of course, with this study, is to generate the data once we get to doses of the 2 drugs that can be combined. But then get generating data in the second-line and we'll of course have a very contemporaneous comparison with the INTRIGUE datas that reports out later this year as monotherapy, really, to understand what the incremental benefit may be of adding a MEK inhibitor to QINLOCK in that setting.

Michael Schmidt -- GuggenheimA -- Analyst

Great, thank you.

Operator

Thank you. Our next question comes from the line of Ren Benjamin with JMP Securities. Your line is open.

Ren Benjamin -- JMP Securities -- Analyst

Hey, good afternoon guys. Thanks for taking the questions and congrats on the quarter. Maybe just focusing on the China approval, can you provide any sort of color as to how we should be thinking about the launch or, how Zai Labs is preparing for the launch. How big their sales force could be? And I guess I'm just trying to get an idea as to how we should be thinking about the trajectory. Is it more, kind of like how things are going here in the US is what you would expect there, or should we be thinking more along how things are going in the rest of the world or some mix of the two?

And maybe just an accounting one for Tucker is, Tucker, do we expect the royalty revenues to come in in the second quarter of this year or is there a one quarter delay? Thanks.

Steven Hoerter -- President & Chief Executive Officer

Yes, Reni, it's Steve. So, I'll take the first part of that and then turn it over to Tucker. So we know that Zai Lab has disclosed with respect to GIST in China, which is that there are 30,000 new patients each year in China with GIST. So it's of course a sizable population and sizable opportunity. I think when it comes to a drug like QINLOCK which Zai as they've guided to plans to launch here later in quarter two. I think the launch trajectory and ultimate opportunity really depends upon the ability of Zai to access the full opportunity and for the patients with just in China, broadly speaking to have access to an innovative medicine. I know that's something that Zai is really focused on. They haven't provided any additional color or refinement in terms of what to expect in terms of ramp of QINLOCK with the China launch.

Tucker Kelly -- Executive Vice President & Chief Financial Officer

Ren, it's Tucker. Just to take the second part of your question, we would expect when they make a sale on their end and have patients being prescribed QINLOCK that we would then recognize the royalty revenue. I think Zai hasn't yet guided exactly when they expect to be in market with the drug. So, we just have to wait and see the kind of their -- specific to the launch timing, but otherwise we would expect it to be when they're making sales on their end.

Ren Benjamin -- JMP Securities -- Analyst

Got it and then maybe just as a quick follow-up. I saw the two rebastinib updates, one in the second quarter at ASCO another one in the third. Am I missing the carboplatin study is -- are we expecting an update from that at some point?

Steven Hoerter -- President & Chief Executive Officer

Yes, thanks for the question, Ren. Matt, do you want to take that in terms of data flow coming from the rebastinib program?

Matthew Sherman -- Chief Medical Officer

Yes, so as you as you highlight, we're continuing with the combination of rebastinib in combination with paclitaxel with the highlights this year for both the endometrial cancer cohort and the platinum-resistant ovarian cancer cohort. We also have a combination study in combination with carboplatin and that's currently being studied in patients with platinum-sensitive ovarian cancer. We haven't provided an update yet as to when we'll be updating those data.

Ren Benjamin -- JMP Securities -- Analyst

Okay. I just want to make sure it was -- still is continuing to move forward. Thanks very much guys.

Operator

Thank you. [Operator Instructions] Our next question comes from the line of Peter Lawson with Barclays. Your line is open.

Peter Lawson -- Barclays -- Analyst

Great, thanks for the, for the update. Just on the cash runway, Tucker that was extended out, was there a reason why?

Steven Hoerter -- President & Chief Executive Officer

Tucker it looks like you may be on mute, Tucker.

Tucker Kelly -- Executive Vice President & Chief Financial Officer

Apologies. Yes, sorry, Peter, it's Tucker. Absolutely every quarter we look at our operating expenses and historicals and update our forecast going forward. So, no, there really wasn't a significant change by any means in our assumptions underlying it. We just have a little bit more history to look at and better ability to try and forecast the cash runway and in this case, we're able to push it out into the first half of 2023.

Peter Lawson -- Barclays -- Analyst

Got you. Thank you. And then just on the, I guess the real world setting for QINLOCK just the duration of treatment you're seeing, if there's anything you can talk through?

Steven Hoerter -- President & Chief Executive Officer

Yes. Thanks, Peter. Dan, do you want to comment on that?

Daniel Martin -- Chief Commercial Officer

Sure. So Peter, I just want to make sure I answer your question. In my prepared remarks, I just laid out that we are starting to see that persistent to care emerge and it's looking similar to KM curves for PFS from INVICTUS. Was there something specific that I could provide more color on?

Peter Lawson -- Barclays -- Analyst

Yes, I guess that probably addresses it. I was just kind of trying to work out, if it was longer, shorter than what you've seen in the trial, but it sounds like it's similar.

Daniel Martin -- Chief Commercial Officer

Yes.

Peter Lawson -- Barclays -- Analyst

Got you. And then --

Daniel Martin -- Chief Commercial Officer

And just -- sorry, Peter. And just to note, right, we always get asked about average versus median. It's just too early to know about whether the average will be longer than the median. We would expect it to be somewhat longer based on data that we've seen in clinical trials, but that's something that we'll continue to let the data mature to help inform.

Peter Lawson -- Barclays -- Analyst

Thank you. And then just I guess another question around the MEK inhibitor, it sounds like it enhances durability, but it I mean is there any chance that it enhances overall response rate or that's sounds like that's ruled out?

Operator

Thank you. Our next question comes from the line of Robyn Karnauskas with Truist Securities. Your line is open.

Unidentified Participant

Hey guys, this is [indecipherable] on for Robyn.

Steven Hoerter -- President & Chief Executive Officer

Yes, please go ahead.

Unidentified Participant

Thank you so much for taking my question. So barring the impact of COVID for QINLOCK, do you see any additional levers to enhance uptake in fourth line, what sort of feedback you've been getting from doctors especially around safety and this is in relation also to the second line program that's ongoing. Can you remind us about safety concerns around Sutent and if you're hearing anything about down dosing regimen that's used in the real world setting?

Steven Hoerter -- President & Chief Executive Officer

Yes. Hi, it's Steve. So I'll take that question. And Peter if you're still listening will come back to your question. I think we were having a mute issue, but I'm want to come back to the question that you asked as well. So with respect to Sutent and how it's used in real world setting, yes, I mean the very consistent feedback that we hear from investigators and some physicians who use this drug is that it is common for the drug to be dose reduced as a result of tolerability challenges. So that is something that we understand as a fairly common occurrence.

Unidentified Participant

And are you hearing any sort of feedback around QINLOCK safety in the real world that you think is different from what you saw in the clinical setting?

Steven Hoerter -- President & Chief Executive Officer

We hear with respect to QINLOCK very consistent feedback, that's consistent with our label and the clinical experience that the drug is well tolerated and there -- and I think physicians view it that way, especially relative to other options that are available to them into their patients with just. So I think the drug is used as being a well-tolerated effective option for patients.

Unidentified Participant

Great and one more question if I may. For the data readout from the Phase II trial in fourth quarter, what can you tell us about what do we expect? Do we see top line data, whether it's met the endpoint or not or more detail than that or should we expect a more detailed presentation at a medical conference later. Just the topline.

Steven Hoerter -- President & Chief Executive Officer

I think it's fair to expect that we'll have a relatively fulsome on top line readout smaller than what we did for the INVICTUS study when we reported out those data. So we will seek to provide relevant information on the primary endpoint of the study as well as the tolerability profile of the drug based on the experience in the INTRIGUE study.

Unidentified Participant

Okay, great, thank you so much.

Steven Hoerter -- President & Chief Executive Officer

Great, thanks. And then I just wanted to come back Peter to your question that you asked with respect to the MEK inhibitor combination and whether we might expect to see more tumor cell killing or more of a satisfied response with that combination versus simply a prolongation of response and Matt I wanted to ask if you would like to address that based on the preclinical data that we've generated and what's been published now [indecipherable].

Matthew Sherman -- Chief Medical Officer

Sure. Yes, I think is very important to recognize that there was a pilot study was done, an investigator responsive study at Memorial Sloan-Kettering that it was presented at ASCO last year was the combination of MEK ripretinib, so basically the same preclinical rationale than that we've discussed today.

The investigator data was able to show -- that was a cohort of about 40 patients, an objective response rate of 68% and that compares very favorably to the historical activity of about 50% for single imatinib. The progression-free survival from that combination was 29.9 months, again greater than the reported PFS for single-agent imatinib of 18.9 months. And the overall survival had not been reached in the combination study that was presented. So again, it gives us some real world evidence and some early data to support the combination of imatinib with ripretinib in this planned study.

Operator

Thank you. I'm showing no further questions in the queue. I would now like to turn the call back over to Steve for closing remarks.

Steven Hoerter -- President & Chief Executive Officer

Great. I'd just like to thank all of you for joining us for today's call, and thank you for your continued support of Deciphera. We look forward to keeping you updated on our progress throughout the rest of 2021. Hope you all have a great evening. Thank you.

Operator

[Operator Closing Remarks]

Duration: 50 minutes

Call participants:

Jen Robinson -- Vice President of Investor Relations

Steven Hoerter -- President & Chief Executive Officer

Daniel Martin -- Chief Commercial Officer

Matthew Sherman -- Chief Medical Officer

Tucker Kelly -- Executive Vice President & Chief Financial Officer

Daniel Wolle -- JPMorgan -- Analyst

Chris Raymond -- Piper Sandler -- Analyst

Eun Yang -- Jefferies -- Analyst

Michael Schmidt -- GuggenheimA -- Analyst

Ren Benjamin -- JMP Securities -- Analyst

Peter Lawson -- Barclays -- Analyst

Unidentified Participant

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