Karyopharm Therapeutics Inc. (KPTI) Q3 2017 Earnings Report, Transcript and Summary

Good morning. My name is Liz, and I will be your conference operator today. At this time, I would like to welcome everyone to the Karyopharm Therapeutics Third Quarter 2017 Financial Results Conference Call. [Operator Instructions] Please be advised that this call's being recorded at the company's request. I would now like to turn over to Mr. Christopher Primiano, Senior Vice President, Operations, Business Development, General Counsel and Secretary of Karyopharm therapeutics.

Thank you, Liz, and thank you all for joining us on today's conference call to discuss Karyopharm's third quarter 2017 financial results. This is Chris Primiano, and I'm joining today by Dr. Michael Kauffman, Chief Executive Officer; Mr. Michael Falvey, Chief Financial Officer; Dr. Sharon Shacham, Founder, President and Chief Scientific Officer; and Dr. Jatin Shah, our Vice President, Clinical Strategy. On the call today, Michael Kauffman will make some introductory comments and provide a short update on the clinical development programs and plans. Then Mike Falvey will provide an overview of the third quarter of 2017 financial results. Dr. Kauffman will then discuss our key upcoming milestones and provide some summary remarks, and we'll open up the call up your questions for which Dr. Shacham and Dr. Shah and I will also be available. Earlier this morning, we issued a press detailing Karyopharm's results for the third quarter 2017. The release is available on our website at karyopharm.com. Before we begin our formal comments, I'll remind you that various remarks we will make today constitute forward-looking statements for purposes of the Safe Harbor provisions under the Private Securities Litigation Reform Act of 1995. These include statements about our future expectations, clinical developments and regulatory matters and time lines, the potential success of our product candidates, financial projections, and our plans and prospects. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including those discussed in the risk factors section of our quarterly report on Form 10-Q for the quarter ended June 30, 2017, which was filed with the SEC on August 8, 2017, and any other filings we may make with the SEC, including our quarterly report on Form 10-Q for the third quarter of 2017, which we expect to file later today. Any forward-looking statements represent our views as of today only and should not be relied upon as representing our views as of any subsequent date. While we may elect to update these forward-looking statements at some point in the future, we specifically disclaim any obligation to do so even if our views change. Therefore, you should not rely on these forward-looking statements as presenting our views as of any date subsequent to today. In addition, please note that any references we make to clinical trial data during today's discussion refer to interim site data unless otherwise specified. I'll now turn the call over to Dr. Michael Kauffman, Chief Executive Officer of Karyopharm.

Thank you, Chris, and good morning, everyone. Thank you for joining us on today's call. Let me start by saying that we've had an active third quarter, and we're extremely proud of our recent progress. Of particular notice is the recent execution of an exclusive licensing transaction with Japanese oncology leader Ono Pharmaceutical Co. Ltd. for the development and commercialization of our lead SINE compound selinexor and for second-generation SINE compound eltanexor, also known as KPT-8602, for our all-human oncology indications in Japan, South Korea, Taiwan, Hong Kong and the ASEAN countries. Ono markets several blockbuster oncology drugs in Japan, including Opdivo, also known as nivolumab, and Kyprolis, which is also known as Carfilzomib. Across these 2 products, Ono has specific expertise in multiple myeloma, Hodgkin's disease and a variety of different solid tumors, making them an ideal partner to advance both selinexor and eltanexor in Japan and the other licensed territories. The transaction, which carries a total deal value of up to $193 million plus royalties, includes a onetime upfront fee of 1 - of USD 22.3 million to Karyopharm from Ono and USD 170.7 million if certain specified future development and commercial milestones are achieved by Ono. These amounts are based on the currency exchange rates on October 11, 2017, the effective date of the license agreement. Karyopharm is also eligible to receive low double-digit royalties based on future net sales of selinexor and eltanexor in the licensed territories. In exchange, Ono receives exclusive rights to develop and commercialize both compounds in the license territories at its own cost and expense. Ono will also have the ability to participate in any global clinical study of selinexor and eltanexor at their own cost and expense for patients enrolled in the licensed territories. Ono is well known and widely respected for its clinical development and commercial expertise, and this partnership provides nondilutive funding to Karyopharm as well as important validation for both selinexor and eltanexor while allowing us to remain focused on executing our late-phase selinexor trials and pursuing regulatory approvals in the U.S. and European Union. Next. We are looking forward to an exciting American Society of Hematology Annual Meeting this year. We've had more than 14 abstracts selected to the meeting, including 3 oral presentations. Amongst the selected abstracts will be 4 poster presentations featuring clinical data from the ongoing Phase 1b/2 STOMP study, evaluating the backbone of selinexor plus low-dose dexamethasone to a variety of other antimyeloma agents. The 4 STOMP presentations will include: Updated data from 2 arms evaluating selinexor in combination with Velcade or with Pomalyst and low-dose dexamethasone, and new data from 2 arms evaluating selinexor in combination with Revlimid or with Darzalex and low-dose dexamethasone. Given its novel mechanism and ease of oral administration, we believe selinexor has the potential to become a backbone therapy in combination with a variety of other anticancer agents for the treatment of myeloma. In addition, the study arm evaluating the combination of selinexor and Velcade, for which enrollment has completed 42 patients, is most similar to the patient population being evaluated in our ongoing pivotal Phase 3 BOSTON study. In addition to the STOMP clinical data presentations at ASH, there will also be presentations highlighting clinical data from several investigator-sponsored trials evaluating selinexor in combination with other therapies along with preclinical data on selinexor, eltanexor and KPT-9274. Turning now to our other myeloma trials. The ongoing Phase 2b STORM study continues to accrue well. STORM is evaluating oral selinexor in patients with penta-refractory myeloma, which we believe represents a significant unmet medical need. This is our most anticipated near-term data readout and milestone, and we remain on track to report top line response data in April 2018. If we continue to see the robust responses and durability that we reported last year at ASH, we intend to submit the full STORM data to the U.S. Food and Drug Administration in the second half of 2018 with a request for accelerated approval for selinexor as a new treatment for patients with penta-refractory multiple myeloma. We believe that the addressable peak market size for this population is approximately $500 million. The pivotal randomized Phase 3 BOSTON study, which I mentioned earlier, is also underway, evaluating oral selinexor in combination with Velcade and low-dose dexamethasone, a regimen we call SVD compared to Velcade and low-dose dexamethasone. The study is in patients with myeloma, and we've had 1 to 3 prior lines of therapy. On the experimental arm, the dosing regimen includes 100 milligrams of oral selinexor once weekly, 1.3 milligrams per milligram of Velcade subcutaneously also once weekly for 4 out of every 5 weeks and 40 milligrams of dexamethasone weekly, so-called low-dose dex. The BOSTON study incorporates 2 important novel innovations into Velcade-based myeloma regimens. First, to the best of our knowledge, this is the only Phase 3 study to evaluate once-weekly subcutaneous Velcade in the experimental arm. Once-weekly Velcade is a regimen often preferred over the standard twice-weekly regimen by many physicians and patients because it carries a significantly reduced risk of peripheral neuropathy and other adverse effects and typically requires only once-weekly office visits. Second, the trial when done permits patients on the control arm who received standard twice-weekly Velcade to cross over to the SVD arm once progression has been confirmed by the independent review committee. We believe that these innovative designs make the trial attractive for both caregivers and patients. In BOSTON, the 2 primary endpoints are the differences in progression free survival as well as the overall response rate between the 2 arms. We expect this study to enroll approximately 360 patients at over 100 clinical studies internationally with accrual projected to complete in 2018 and top line data expected in 2019. Assuming a positive outcome from the BOSTON study, we expect to be well positioned to support a request for full approval of selinexor in combination with Velcade and dexamethasone for patients with at least 1 prior therapy for their myeloma. Moreover, we believe that this simplified once-weekly Velcade-based therapy can become an important and convenient regimen for patients relapsing after front-line therapy. We estimate that the addressable peak market size from myeloma patients relapsing after at least 1 prior regimen is several billion dollars. In addition to myeloma, we are also developing selinexor for the treatment of diffuse large B-cell lymphoma, and I'd like to take a moment to discuss the DLBCL landscape and how we believe oral selinexor fits in. Approximately 60% of patients with DLBCL are fortunate enough to be cured. About half with initial therapy, typically R-CHOP, and another 10% with high-dose chemotherapy followed by autologous stem cell transplantation in the second line. There is no standard of care therapy for the remaining 40% of patients or about 10,000 patients per year in the U.S., and novel agents are required. Chimeric antigen receptor modified T-cells, more commonly referred to as CAR-T therapy, are being explored. And the first CAR-T for DLBCL, Gilead's Yescarta, has received accelerated approval for the minority of patients who are medically able to safely undergo this therapy. We believe that selinexor, which is an easily administered oral therapy, represents a completely novel option for the vast majority of DLBCL patients who are not fit enough for CAR-T therapy and even those whose disease relapses after CAR-T therapy. We reported updated data earlier this year from the ongoing Phase 2 B SADAL study in patients with relapsed or refractory DLBCL, where selinexor demonstrated a 33% overall response rate and immediate - median duration of response of over 7 months. The efficacy was similar in both the 60-milligram and 100-milligram treatments arms, and the adverse events across both arms were predictable and manageable. However, we and the FDA agreed to amend the SADAL study to a single-arm trial evaluating only the 60-milligram twice-weekly dose when we saw improved tolerability and time on therapy. Thus, we plan to enroll a total of 130 patients in the 60-milligram cohort and expect to report top line results from the completed SADAL study in the second half of 2018. Assuming we continue to see the response rate and durability observed to-date, we plan to use the data from the SADAL study to support the submission of the new-drug application with a request for accelerate approval in the U.S. for single-agent selinexor as a new treatment for patients with relapsed or refractory DLBCL having received at least 2 prior lines of therapy. We believe that the addressable peak market size for these patients with relapsed or refractory DLBCL is approximately $500 million. Beyond hemologic malignancies, we're also developing selinexor in certain solid tumor indications. In our most advanced solid tumor trial, we recently reported the successful outcome from the Phase 2 portion of the Phase II/III SEAL study investigation - investigating selinexor in patients with advanced liposarcoma. For the primary endpoint of progression-free survival, oral selinexor given at 20 - given at 60 milligrams twice weekly showed superiority over placebo, achieving a hazard ratio of 0.6 as assessed by independent central radiological review and based on RECIST version 1.1 criteria. In this randomized blinded Phase 2 portion of the study, oral selinexor 60 milligrams twice weekly demonstrated and expected and manageable safety profile primarily with nausea, anorexia and fatigue and low levels of grade 3/4 cytopenia. No new or unexpected safety signals were identified. A majority of treatment-related adverse events were low grade and reversible with dose modifications and/or standard support of care. Importantly, the incidence of infections in the selinexor arm was less than that reported in the placebo arm. We plan to the detailed results from the Phase 2 portion of the SEAL study for presentation in a future medical meeting. The Phase 3 portion of the SEAL study is underway and has been expanded beyond North America to include Europe. In this blinded placebo-controlled Phase 3 portion of the study, up to 222 patients will be enrolled and randomized 2:1 to receive either oral selinexor until disease progression or intolerability or to placebo. Patients whose disease progresses on placebo will be permitted to cross over to the selinexor arm. The primary endpoint of the Phase 3 portion of study is PFS, progression-free survival, and both the primary endpoint and study design were agreed to by the USFDA as acceptable for approval. Top line data from the Phase 3 portion of the SEAL study are anticipated by the end of 2019. Assuming a positive outcome, these data are expected to support an NDA for oral selinexor as a potential new treatment for patients with advanced, unresectable dedifferentiated liposarcoma. One additional solid tumor indications where we view selinexor as having significant potential is in the gynecologic malignancies, both ovarian and endometrial cancers. At ESMO 2017, Dr. Vicky Makker of the Memorial Sloan Kettering Cancer Center presented clinical data from a Phase 1 study evaluating selinexor in combination with Paclitaxel and Carboplatin in patients with heavily pretreated ovarian or endometrial cancers. This poster presenter highlighted the manageable safety profile and compelling responses observed when combining oral selinexor with these standard chemotherapies. [Indiscernible] 2-dose regimen was established and expansion cohorts to the RP2DR plan. Before I move on to our other pipeline assets, I'd just like to highlight the emerging overall safety profile for selinexor. We are no longer treating patients with doses higher than 80 milligrams twice weekly, and the dosing regimens that are being utilized in our key trials, including BOSTON, STORM, SADAL, STOMP and SEAL, continue to show that selinexor has a manageable safety profile, particularly when used once weekly in the combination regimens under study. The adverse events we are seeing are highly predictable and manageable with standard supportive care and/or dose modification, and patients have been on selinexor for more than 1 to 2 years. Turning now to the pipeline assets beyond selinexor. In September, clinical data from a Phase 1 study evaluating KPT-9274, our dual inhibitor of PAK4 and NAMPT in patients with advanced solid tumor malignancies, including sarcoma, colon and lung cancers, were presented at ESMO 2017. In his poster presentation, Dr. Aung Naing of the MD Anderson Cancer Center in Houston highlighted safety and early efficacy data that suggests that oral KPT-9274 can reduce tumor shrinkage and disease stabilization in patients whose disease has progressed despite most available therapies. In addition, these results show that niacin can be safely administered with KPT-9274 and may improve tolerability, particularly with regards to anemia. Dose escalation in the study remains ongoing. Next I'll be handing over the call to our newly appointed Chief Financial Officer, Mike Falvey, who will discuss the financial highlights from the quarter. But first, I'd like to introduce both Mike and Dr. Jatin Shah, our Vice President of Clinical Strategy. Mike joined Karyopharm as Chief Financial Officer and Treasurer in September 2017. He brings more than 25 years of experience in executing business growth and financial strategies for both public and private companies, including senior financial leadership roles at life science organizations. Prior to joining Karyopharm, Mike served in executive finance leadership roles at several high-growth, revenue-generating companies, including Analysis Group, Aspect Medical Systems and Millennium Pharmaceuticals. Mike leads our financial and capital market strategy and advises on business development and transactional activities. Dr. Jatin Shah joins us from MD Anderson Cancer Center, where he was associate professor of myeloma clinical and translational research. He brings significant medical and hematological oncology experience, including treating patients with multiple myeloma and in clinical research more broadly. Jatin is responsible for overseeing the clinical development strategy across all our drug candidates, including coordinating with investigators and KOLs and leading the medical monitoring of all clinical studies. We are delighted to have both Mike and Jatin on the team as we head into this critical and exciting time for the company. Mike?

Thank you, Michael. Since we issued a press reason earlier today outlining our third quarter 2017 financial results, I'll just review the highlights and then speak to our cash balance and financial guidance. Cash, cash equivalents and investments as of September 30, 2017, including restricted cash, totaled $159.4 million compared to $175.5 million as of December 31, 2016. For the third quarter of 2017, research and development expense was $25.2 million compared to $19.9 million for the same period of last year. For the third quarter of 2017, general and administrative expense was $5.8 million compared to $5.9 million for the same period last year. Karyopharm reported a net loss of $30.6 million or $0.65 per share for the third quarter of 2017 compared to a net loss of $25.4 million or $0.69 per share for the same period last year. Net loss includes stock-based compensation expense of $4.9 million and $5.6 million for the third quarters of 2017 and 2016, respectively. For financial guidance for 2017, we expect our operating cash burn, including research and development and general and administrative expenses to be approximately $95 million. Based on current operating plans, we expect that our existing cash and cash equivalents will be sufficient to fund our research and development programs and operations into 2019, including the continued clinical development of selinexor in our lead indications with a focus on filing for accelerated approval in myeloma during 2018, assuming positive data from the STORM study, and preparing a commercial infrastructure for the potential launch of selinexor in North America and Western Europe. I'll now turn the call back over to Michael Kauffman for concluding remarks. Michael?

Thank you, Mike. I'm very proud of our progress in 2017. And just before we have questions, I'd like to recap our expected milestones. For STORM, we expect top line data from penta-refractory myeloma in April 2018, which if positive, is expected to support an NDA submission in the second half of 2018 requesting accelerated approval. For SADAL, we expect top line data the second half of 2018, which if positive is expected to support an NDA submission request for accelerated approval in 2019. For Velcade and Pomalyst arms, we're presenting updated data at ASH and will also be presenting new data for Revlimid and the Darzalex combination arms at ASH 2017. For the pivotal Phase 3 BOSTON study, we expect to complete enrollments in 2018 with top line data anticipated in 2019. And for our solid-tumor programs, we're expecting executing on the Phase 3 portion of the SEAL study, and we expect to report top line data by the end of 2019. We believe we have the potential for multiple exciting catalysts on the near horizon, and we'll continue to work diligently to advance selinexor's potential as a new treatment paradigm for patients suffering from myeloma, DLBCL, liposarcoma and other neoplasms. Thank you for listening today. We'll now open the call for questions. Operator?

[Operator Instructions] Our first question comes from the line of Mike King with JMP Securities. Your line is now open.

Michael, just wanted to ask about STOMP and how we should think about it kind of overlaying on the development of selinexor in multiple myeloma as those trials continue to hit, whereas their arms continue to hit their enrollment goals. How do you foresee supplementing the lead application via STORM? Are these going to be sNDAs? Will these follow BOSTON? Are they for publication purposes only? I was hoping maybe you could give us a little bit of clarity on how those arms will fill out the dossier?

Sure. Well, there are 4 arms - 4 major arms on the STOMP study. Obviously, the Velcade arm is being used today in the ongoing Phase 3 Boston study, so that'll be a - if the results are positive, that would potentially support a full approval in second-line myeloma for sel-vel-dex versus vel-dex, so that's how we will use that arm. The other arms are being investigated with the potential to support additional randomized trials in the future for full approvals, and all of those regimens are potentially useful in that regard towards a full approval. But short of that and given the time frames involved, we would anticipating - that we would anticipate filing all of them with the various NCCN guideline groups and other people compendia listings so that we can have at least compendia listings as we progress them to full approval. And I'd also remind everyone that the FDA has taken a bit of a broader view of things recently, and the dara and pom combination, which was based on - was approved, was given an accelerated approval based on the Phase I/II data that were generated in that study. So one can imagine that we might be available for some of those kinds of options once we have a full approval. Let me ask Jatin to also talk about how we can move - so how we're thinking about moving selinexor into the newly diagnosed arena as well? Jatin?

So maybe I think I'll highlight just a couple other medically relevant kind of takes on that. And I think one is the fact that we're able to combine selinexor with all the other kind of therapeutics in the myeloma space, including carfilzomib, as shown previously, and now with both Imetelstat and daratumumab. So I think this is especially relevant for the treating community, moving forward in that we're having high response rate so we connote that in our pomalidomide arm, for example, we saw high activity both from len refractory pom naive patients, which is very similar to what we see with pom-dara-dex. Also, I think this is data that's very promising moving forward that we can combine it with all the other therapeutics and move them into various other lines. And then I think this also sets us up to move into earlier lines of therapy, realizing - including early diagnosed as Michael referred to as Revlimid is more commonly used in that front-line therapy setting as well, so now that we're able to combine with lenalidomide or Revlimid, we'll be exploring moving that into the front-line therapy both for transplant eligible and ineligible patients into those - find some opportunities there.

Our next question comes from the line of Brian Abrahams with RBC Capital Markets. Your line is now open.

This is Rick on for Brian. Congrats on the STOMP updates and the ASH abstracts, and we're looking forward to seeing the complete data. Compared to the last cutoff for STOMP, the overall response rates among PI-refractory patients appears to have come down a bit. Could you talk about any of the differences in the PI-resistant population recruited later in the study? Remind us of the dosing in these patients and whether anything in your baseline characteristics may have led to the slower response.

Yes. I'll jump in first, and then turn it over to Sharon for additional follow-up since Jatin recently joined us. So one of the things that happens when you get good results in these trials is you start to get sicker and sicker patients, and we definitely had more patients that have Kyprolis refractory myeloma as opposed to simply Velcade refractory myeloma. And so these are sicker patients that have moved into the Velcade refractory arm. And we're actually quite excited because these patients are PI refractory arm. These patients should have a response rate on once-weekly Velcade close to zero, and that's really important to remember. These patients are refractory to full-dose proteasome inhibitors so giving them half a dose of Velcade is not going to induce a response. And we're actually quite excited about this. And in fact, these data continue to support one of our secondary endpoints in the BOSTON study, which you - which look at the response on SVd for patients that crossed over from the Velcade dex arm that have directly refractory disease. And if that arm is positive with significant response rate, we would file for that as an additional potential indication from the BOSTON study. I'll turn it over to Jatin or Sharon, if you have anything to add.

No. I think Michael has described it correctly. We saw more of the quad or even [indiscernible] refractory patient, some coming into the second part of both - of the SVd arm once we opened the expansion.

Thank you. One of the highlights - just to add quickly, is that even the PFS shown in that arm is quite substantial at about 9 months, which is pretty good for a Velcade refractory population, where again, you'd see minimal response rate at all and an expected PFS on Velcade of maybe 1 or 2 months.

Yes. And I think it's - the depths of the response didn't change much and the [DOR] as well as - very promising. So in overall, the activity of the SVd combination still looks great.

Our next question comes from the line of Arlinda Lee with Canaccord. Your line is now open.

On 9274, how do you guys think about that development of the concept of your exo inhibitors? And then, I guess, maybe more focusing on SADAL and DLBCL, how many extra patients due to enroll in the expansion cohort? What do you think there hurdle would be for an accelerated approval? And maybe a little bit more detail on whether you think you might be able to file in, I guess, '19 now.

Yes. So let me answer the second part, and I'll turn it over to - 9274 question to Dr. Shacham. The SADAL sign-ons are what we said before, the data - the top line data from the final cohort of 130 patients will be available in the second half of next year, and we will file as expeditiously as we can after that - after those data come out. So that really hasn't changed. We had 30 patients at the 60-milligram dose initially, and we're adding approximately 100 more patients to that group, which is ongoing and improving nicely, so we're happy...

So about the 9274, it's in Phase 1 in solid tumors and lymphoma. And we also - the science around NAMPT inhibition is very different, and that's the one extra one inhibitor indication based on the inhibition of NAMPT and PAK4. We are looking for biomarkers and specific indications and also looking at the combination that we will follow up immediately as we will identify the recommended Phase 2 dose of the single agent in KPT-9274.

Our next question comes from the line of Maury Raycroft with Jefferies. Your line is now open.

So following up on the STOMP SVd combo PR refractory patients. I'm wondering if those patients were mostly twice-weekly Velcade? Or was it more of a split between once- and twice-weekly dosing? And if patients are on once weekly and they start to respond, can they be stepped up to twice weekly to maintain the response?

So the vast majority of patients on STOMP received selinexor once weekly. It's only 3 patients that received - sorry but only once weekly. Only 3 patients received bortezomib twice weekly. And that's the already - there is cognitions at - and so in the penta-refractory, it's almost all the patient received both only once weekly. In the protocol what we allow is for patients that are receiving 100 once weekly, if they tolerate well and they didn't reach the PR, then we allowed them to receive selinexor twice weekly. And some patients we did that. But we are not moving from once weekly, both of them move to twice weekly bortezomib because as we said, bortezomib is helping enhance the deep activity of selinexor in this patient, and we don't need more than once-weekly bortezomib to achieve that. We will just get more thrombocytopenia and that obviously related to Velcade.

And along those lines of selinexor helping resensitize patients to Velcade in the refractory setting, I'm wondering for the pom - Pomalyst plus selinexor combo data where you show the overall response rate of 29% in refractory patients. Do you think selinexor is helping resensitize in those patients too? Or is something else going on?

Can you please repeat which patients?

The STOMP pom plus selinexor in the refractory patient. The pom plus Revlimid refractory.

So it's hard to say and we are following it closely, there is definitely a patient that would see pom in the past and now pom refractory and had a response. And the response rate there is more than what we would see in STOMP, so single agents that are excel. So you might think that there is some synergy there even in the pom refractory, but as we identify the recommended dose and move to extension, we will be able to answer this question in more detail.

And last question is based on the selinexor plus Darzalex combo. Can we expect to see some additional patients at the meeting?

Of course.

Any estimate as to how many?

It's a ongoing Phase 1 study, so there's 3 plus 3 design. And so it will be more patients than what you see now.

Our next question comes from the line of Michael Schmidt with Leerink. Your line is now open.

I just had a couple follow-ups regarding the multimyeloma combination with Velcade. How does the patient population differ? Any expectation between the BOSTON trial and the STOMP Velcade arm? Does the BOSTON trial exclude prior Velcade? Or does it include, for example, patients that received Velcade previously.

No. They can receive Velcade at once. In the past, they actually can receive any proteasome inhibitor in the past. They may need to be proteasome inhibitor. They cannot be refractory to a proteasome inhibitor, and then it be 6 months from the last proteasome inhibitor.

I'm just trying to get a sense of, I guess, what would expectations be in the BOSTON trial, for example, how the arm val-dex will perform. And I guess, what would you expect for the once-weekly dex dosing alone in those types of patients?

Once-weekly dex dosing alone?

Yes. I guess, how much is that - if you're - if not all patients are refractory to Velcade, how much contribution would you expect from the once-weekly dex in Boston in the treatment arm relative to selinexor? And then, what expectations for the twice-weekly val-dex control arm in the study for efficacy?

So for the vel-dex, we are following the same design that was used in the Vd versus Kd study, in the ENDEAVOR study, and we took the PFS from that study, so it's 9.3 months, I believe. For the SVd arm, we are expecting the population should be similar to the STOMP study, maybe a little bit earlier line. So we expect - based on our statistical assumptions, we will have similar results to as the Vd combination but - so to get into the 80% response rate area but using only once weekly Vd, so to have better already and minimal neuropathy.

And question - just bigger-picture for [indiscernible], you guys still thinking about the Ono deal in Asia. I think in the past, you've, I think - coming in around potentially partnering selinexor in Europe as well, but then I think I heard you say today that you think about rolling out commercially in Europe yourself. Just wondering how you think about European commercially patient at this point.

Yes. So, Michael. This is Chris Primiano. So when it comes to Europe. I think that we're unlikely to be a sort of fully integrated pharmaceutical company at the point that we would expect to and hope to be launching selinexor, so that a partner may be the right choice for us in Europe. But it's not the best choice strategically to just expect that the right partnership is going to be formed at the time that we would like to have it. So we're continuing to prepare to build that commercial infrastructure and to do the right things to set the groundwork to commercialize in a way other than with a partner if necessary, but we certainly view a partner as an appropriate avenue for commercializing selinexor in Europe.

Our next question comes from the line of Mara Goldstein with Cantor Fitzgerald. Your line is now open.

Just to follow up on that last question. What would be the timing for a regulatory then submission in the EU if you do not have a partner at the time that you're ready to make that submission?

Michael?

Which - yes, which submission, sorry, are you speaking about?

The European...

For Europe. For your first - yes...

Yes, so there's a couple of points. One is that both STORM and SADAL are being conducted in Europe as well as in the U.S. Both of those are obviously single-arm trials and would be potentially submitted for conditional approval in Europe. The timing for them would be a bit after the U.S. submissions would be made and pending scientific advice discussions, including the results into Europe, so we could be in Europe in mid-'19 with the STORM plan. BOSTON would be about a year later-or-so.

And then, just - can you just remind us on 8602, what would your anticipation be of the clinical differentiation between 8602 and selinexor?

Sharon will take that.

So just a reminder, 8602 is another - is a second-generation next SINE inhibitor with minimal well penetration, and what we see and reported in the abstract that it has still marked activity but improved tolerability. And - but its activity is taking a different course. What we believe is, obviously, for all the diseases that are related with - to brain tumors or that there is a chance for brain metastasis, selinexor will be developing in these indications of course him and solid tumors. In addition, selinexor seems to be a better partner for the immunotherapy drug as it allows for the immune system - it doesn't arrest the immune system with the once-weekly dosing if we are using in combination. For other combinations with the mark's profile in terms of tolerability of 8602, we will develop it in combination with other drugs that have a very good tolerability profile in indication - in solid tumors and potentially some indication on this space?

[Operator Instructions] Our next question comes from the line of David Nierengarten with Wedbush. Your line is now open.

I just had a - maybe an earlier-stage question on selinexor. Have you looked at combinations at preclinically? And with any of the BCMA antibodies or constructs - anticipating future drug development there on that side?

We haven't done those combinations yet, but we are looking to look into do them.

I'm showing no further questions in queue at this time. I'd like to turn the call back over to Dr. Kauffman for any closing remarks.

Just want to thank you listening to today's call, and we apologize for slight interrupt. We look forward to seeing many of you at ASH at our data presentations - events. Details for that event will be going out shortly and have a good day. Bye, bye.

Ladies and gentlemen, thank you for your participation in today's conference. This concludes the program, and you may now disconnect. Everyone, have a great day.