
Zymeworks Inc.
3/6/2024
Thank you for signing by. This is the conference operator. Welcome to ZymeWorks' fourth quarter and year-end 2023 results conference call and webcast. As a reminder, all participants are in listen-only mode, and the conference is being recorded. After the presentation, there will be an opportunity to ask questions. To join the question queue, to ask a question, please press star, then 1-1 on your telephone keypad. I would now like to turn the conference over to Srinath Inamda. Director of Investor Relations, Trinnell, please go ahead.
Thank you, operator. Good afternoon. I'd like to welcome you all to our fourth quarter and year end 2023 results conference call. Before we begin, I'd like to remind you that we'll be making a number of forward looking statements during this call, including without limitation those forward looking statements identified in our presentation slides and the accompanying oral commentary. These forward looking statements are based upon our current expectations and various assumptions. and are subject to the usual risks and uncertainties associated with companies in our industry and at our stage of development. For discussion of these risks and uncertainties, we refer you to our latest SEC filings as found on our website and as filed with the SEC. In a moment, I'll hand over to Dr. Chris Assel, our Senior Vice President and Chief Financial Officer, who will be discussing recent scientific and corporate updates along with our financial results for the fourth quarter 2023, including certain non-GAAP measures. A description of our non-GAAP measures and a reconciliation to the most directly comparable financial measures as determined in accordance with GAAP are described in our press release, which is available on our website at www.zionworks.com under the Investor Relations tab. Following this, Paul Moore, our Chief Scientific Officer, will talk about key expected milestones that underpin another potentially transformative year for Zyworks, both through expected upcoming regulatory approvals and launches, and more broadly through executing on our development strategy for our early stage project candidates. At the end of the call, Chris and Paul will be joined by our Chair and Chief Executive Officer, Ken Galbraith, for Q&A. As a reminder, the audio and slides from this call will also be available on the Zyworks website later today. I'll now turn the call over to Chris, our Senior Vice President and Chief Financial Officer. Over to you, Chris.
Thanks, Fennell, and thank you, everyone, for joining us today for our fourth quarter and full year 2023 earnings call. With that, I will begin today's call with an overview of key achievements from our development programmes over the course of 2023, as well as our financial results. Throughout 2023, we successfully positioned ZymWorks as a thought leader in the development of antibody drug conduits, or ADCs, and multispecific antibody therapeutics. We have done so through multiple data catalysts from our phase two clinical trials of zamodetamab in both gastroesophageal adenocarcinoma, or GEA, and biliary tract cancers, or BTC, which validate our protein engineering expertise and antibody screening capabilities. We're very pleased to see positive results for these patient populations and look forward to further advancements of Zanadecimab's developments in multiple indications led by our partners, Jazz Pharmaceuticals and Beijing. These developments, coupled with our work on demystifying the ADC dogma by reviewing 40 years of clinical data and taking these learnings to redefine our own approach to develop the next generation of ADCs, are key differentiators for Zyneworks as we aim to develop practice-changing therapeutics and indications with high unmet medical needs. We have significantly accelerated the development timeline for our early stage 5x5 programs, with the majority of our product candidates having now been nominated. Most recently, ZW251, our GPC3-targeting ADC, being developed for the treatment of hepatocellular carcinomas. We remain on track to accomplish our goal of submitting two INDs or foreign equivalent submissions in 2024 for ZW191 and ZW171 and to nominate our fifth candidate with a planned IND submission in the first half of 2026. We also remain on track for two further IND or foreign equivalent submissions in 2025 for ZW220 and ZW251. We have strategically expanded the global footprint of our early-stage development team by establishing a presence in the key locations of Ireland, California, and Singapore in preparation for our clinical development plans. This has allowed us to retain top talent and establish fit-for-purpose facilities, which will enable us to accelerate pipeline development as we move forward with our 555 program. Execution on our strategy throughout 2023 has allowed us, together with our partners, to target late 2024 for the pivotal phase three top line readout from Horizon GA01, where we will see progression-free survival data. Our partners, Jazz and Beijing, also remain on track to complete the biologics license application, or BLA, submission for Xanadetimab in second line BTC by the first half of 2024 in the United States. And in the second half of 2024 in China, with the goal of potentially launching Zanadecimab in the United States and China in 2025 or sooner. We would also like to highlight that, as per recent guidance provided by our partner, JAS, the phase III confirmatory trial to evaluate Zanadecimab as first-line treatment for patients with metastatic BTC has now been initiated. We see the anticipated commercialization of Xanadetimab as a near-term opportunity with more than $2 billion in revenue potential, starting with potential approval in BTC, which remains an area of particular unmet patient need. We agree with the thoughtful approach taken by our partners to seek to take Xanadetimab to market initially in BTC, as it may enable a faster go-to-market strategy and potentially expedite the regulatory review process for other indications where Xanadecimab can leverage SPLA filings. GEA would be the second indication which has a much larger patient population, estimated to be 63,000 HER2-positive cases annually in the United States, Europe, and Japan. JAS has expanded their clinical efforts for Xanadecimab in breast cancer, where there remain many opportunities in both the early stages and late stages of disease. We're also very excited about the potential for Xanadecimab to provide a chemo-free regimen, which we know would be of great value to patients. And we look forward to data from the iSpy program and Jazz's collaboration with MD Anderson. As you can see from this slide, there are many opportunities beyond these indications in other HER2-expressing tumors, which makes Xanadecimab a potentially very rewarding financial investment, both for our partners and for shareholders of ZymeWorks. while also supporting our goal to improve the standard of care for difficult-to-treat diseases for patients with high and met needs. Beyond Xanadetamab, we are pleased to be starting the year having nominated four of the five product candidates that we set out to define a year ago. Today, we have a broad and differentiated pipeline with novel candidates focused on validated targets in areas of significant interest, which continue to provide multiple opportunities for business development and collaborations. We remain committed to advancing the development strategy for our pipeline of unencumbered product candidates, all of which have the potential to increase the standard of care for patients in disease areas with high unmet need and with commercially attractive targets. We believe the next six to 18 months are set to be transformational for Zyneworks as our partners approach potential regulatory approvals and launches and more broadly through the advancement of our differentiated early stage product candidates. Our Chief Scientific Officer, Dr. Paul Moore, will talk more about the future of our pipeline, but first I would like to spend some time on our financial results. This afternoon, SignWorks reported financial results for the fourth quarter and year ended December 31st, 2023. SignWorks' net loss for the year ended December 31st, 2023 was $118.7 million, or $1.72 loss per diluted share, compared to a net income of $124.3 million for the year ended December 31st, 2022. Net loss in 2023, as opposed to net income in 2022, was primarily due to non-recurring upfront fee revenue from our collaboration agreement with JAS in 2022. which was partially offset by higher collaboration revenue, lower operating expenses, higher interest income, and lower income tax expenses in 2023. As reported, our revenue for 2023 was $76 million compared to $412.5 million in 2022. 2023 revenues included $71.5 million for development support and drug supply revenue from JAS, and $4.5 million from our other partners for research support and other payments. Revenue for 2022 included $375 million in upfront fees from JAS, $24.3 million in development support payments from JAS, and a $5 million upfront fee from a tracker, as well as an $8.2 million in research support and other payments from our other partners. Research and development expense was $143.6 million in 2023, compared to $208.6 million in 2022. The decrease was primarily due to a decrease in expenses for Xanadetamab at our transfer agreement and amended and restated collaboration agreement with JAS. This was partially offset by an increase in preclinical expenses, primarily with respect to preclinical product candidates ZW171 and ZW191, and higher Xanadetamab's overdosing program costs. Salaries and benefit expenses decreased due to lower headcount in 2023 and non-recurring severance expenses. General and administrative expenses were $70.4 million compared to $73.4 million in 2022. The decrease was primarily due to a decrease in salaries and benefits expenses due to lower headcount, lower non-recurring severance expenses in 2023, and a decrease in expenses for professional services. This is partially offset by an increase in other expenses related to higher depreciation on facilities and higher technology spending in 2023. Other income net increased by $14.1 million in 2023 compared to 2022 due to income earned on higher cash resources and the higher rates of return in 2023. Income tax expense decreased by $11.5 million in 2023 compared to 2022, primarily due to a reduction in United States taxes under the Global Intangible Low-Taxed Income Rules in 2023. In 2023, we incurred a net loss compared to a net income in 2022, primarily due to the income from the Jazz Partnership in 2022. As of March 4th, 2024, we have approximately 70.6 million shares of common stock outstanding and 5.1 million pre-funded warrants issued in December 2023. As of December 31st, 2023, we had 456.3 million of cash resources consisting of cash, cash equivalents and marketable securities, comprised of 157.6 million in cash and cash equivalents and $298.7 million in marketable security. Based on current operating plans, we expect our existing cash resources as of December 31st, 2023, when combined with receipt of certain anticipated regulatory milestone payments, will enable us to fund planned operations into the second half of 2027. For additional details on our quarterly and year-ended results and for a description of our non-GAAP financial measures and a reconciliation of GAAP to non-GAAP measures, I encourage you to review our earnings release and other SEC filings as available on our website at www.signworks.com. Our strategy of refocusing the business and building our diverse clinical stage product pipeline of ADCs and multi-specific antibody therapeutics continues to provide a solid foundation, helping to achieve our long-term goal of identifying additional product candidates and seeking valuable partnership options with a strong financial position of $456.3 million as of the end of December 31st, 2023. And this, together with certain anticipated regulatory milestones, gives us an expected runway into the second half of 2027. We may also be able to extend this runway through potential additional regulatory and commercial milestone payments in connection with our partnerships with JAS and Beijing. And in addition, pending regulatory approval, we are eligible to receive tiered royalties between 10 and 20% on JASA's annual net sales of Xanadetimab, and between 10 and 19.5% on Beijing's sales. No development or commercial milestone payments or royalties have been received today. With that, I'd like to hand over to our Chief Scientific Officer, Dr. Paul Moore, who will talk about our novel topoisomerase inhibitor, or Topo-1 payload, which is the foundation for three of our ADC candidates and speak more broadly about the key milestones for our early stage pipeline. Over to you, Paul.
Thank you, Chris.
And as you said, I want to start by focusing on our TOPO1 inhibitor platform for which we recently published a manuscript in molecular cancer therapeutics. First of all, it's important to recognize there are significant challenges with repurposing older toxins not originally developed for ADCs. Limitations in their biophysical properties, pharmacokinetic, and pharmacodynamic profiles often result in heightened toxicity levels, diminishing their suitability for ADC applications. As such, our team has sought to design novel compounds specifically with characteristics amenable to bioconjugation to an antibody and that behave like small molecule chemotherapeutics after they are released from the antibody to optimize the full therapeutic potential of this treatment modality. As many on this call will know, in recent years, the field of ADCs has seen a resurgence, largely driven by the clinical benefit observed in patients treated with ADCs incorporating camptothecin-based TOCO1 inhibitor payloads. Advances in the design and engineering of ADCs as mechanisms for targeted drug delivery have widened therapeutic application of this modality and the difference it could make in patients' lives. With this in mind, we would like to highlight our novel campathesin ZB06519, specifically designed for its application in an ADC payload. A commonly held notion in ADC development is that increasing payload potency and bystander activity hold the potential advantage of effectively targeting tumor cells with lower antigen expression. However, it's important to consider that more potent and more permeable payloads may also lead to increased toxicities, potentially requiring a reduction in the antibody dose, a challenge we have seen for many prior assets in the clinic. We believe that higher antibody dose with a moderately potent topoisomerase inhibitor payload could be a preferred strategy to overcome antigen sink effects and enhanced tissue penetration, ultimately leading to increased payload delivery into tumor cells. In addition to linker design and payload potency, intrinsic payload properties such as metabolic stability, susceptibility to transporters, play a crucial role in ultimately determining the efficacy and safety profile for patients. New molecular entities such as campathesin payloads can be selected to address these factors and optimize the overall therapeutic profile of ADCs based on the antibody, target, and indication. Striking the right balance between ADC efficacy and tolerability remains an ongoing challenge, making it a critical factor in designing a new ADC platform, ultimately enhancing the likelihood of clinical success. To identify this novel counterfeiting payload with optimal properties, we leveraged insight from gained from 60 years of Campythesan structure activity relationship data to generate a library of approximately 100 compounds featuring different substituents at the C7 and C10 positions. A panel of Campythesan analogs with different substituents at the C7 and C10 positions of the Campythesan core were then prepared and tested in vitro. Selected compounds spanning a range of potency and hydrophilicity were elaborated into drug linkers conjugated trastuzumab, and evaluated in vitro and in vivo. CD06519 was selected based on its favorable properties as a free molecule and as an antibody conjugate, which include moderate free payload potency of approximately 1 nanomolar, low hydrophobicity, strong bystander activity, robust plasma stability, and high monomeric ADC content. When conjugated to different tumor-targeting antibodies via clinically validated MC-GG-FG-based linker, ZD06519 demonstrated impressive efficacy in multiple xenograft models and noteworthy tolerability in healthy mice, rats, and non-human primates. In the context of addressing poor outcomes often associated with intratumor and intratumor heterogeneity, Our focus has been on designing an ADC with a payload characterized by moderate potency with bystander properties. Our hypothesis revolves around the notion that our payload's heightened membrane permeability facilitates its infiltration into neighboring tumor cells as illustrated in preclinical studies. This strategic design aims to enhance response rates across diverse expression profiles without compromising safety due to toxicities. This slide places out these two characteristics. One is target dependency, which is shown in the left graph, with the desire to have enhanced activity on target-expressing cell lines, indicated in blue, relative to target-negative cell lines, indicated in orange. Something you see nicely achieved with our select payload indicated within the box. On the right, you see data evaluating bystander activity, another important feature we wanted incorporated. In these assays, what we are looking for is a decrease in the viability of tumor-target antigen-negative cells in cold cultures with target antigen-positive cells, shown in brown, but limited impact on the viability of tumor-antigen-negative cells when cultured alone, shown in red. Again, as indicated within the box, we chose a payload demonstrating these features to make sure that when the payload is the least, it is able to also enter and inhibit nearby cancer cells regardless of target antigen expression. and hence maximize anti-tumor activity. Our TOPO-1 inhibitor platform is one of several proprietary Zynwerks linker payload platforms. TOPO-1 inhibitor-based technologies show meaningful clinical benefit in a wide range of solid tumors, including hard-to-treat solid tumors. They have been validated across many targets. Based on empirical findings and their own pre-clinic Preclinical data, we believe our novel payload could provide us with improved efficacy and tolerability and have utilized ZD06519 in three of our ADC product candidates. ZW191, an ADC that targets polar receptor alpha-expressing tumors, including ovarian, other gynecological, and non-small cell lung cancer, is built using our drug conjugate platforms, including our novel TOCO1-based payload technology. A drug antibody ratio of A was selected to balance tolerability and efficacy. The folate receptor alpha monoclonal antibody incorporated in ZW191 was generated in-house, selected based on enhanced internalization characteristics to enable targeting of high, mid, and low levels of folate receptor alpha expression. Folate receptor alpha is a clinically validated target, and data supports its expression in approximately 75% of ovarian carcinomas and in 70% of non-small cell lung cancer. Our preclinical data is encouraging, with strong anti-tumor activity demonstrated across a range of patient-derived non-small cell lung cancer and ovarian xenograft models. ZW220, an ADC that targets sodium-dependent phosphate transporter 2B, or NAPI2B, expressing non-small cell lung cancer and ovarian cancer, is, like ZW191, both using our proprietary TOFO-1 inhibitor-based payload technology. Adara-4 was selected to balance tolerability and efficacy. The NAPI-2B targeting monospecific antibody incorporated in CW220 was generated in-house and selected based on favorable binding profile and enhanced internalization properties to enable targeting of both high and low-expressing NAPI-2B-expressing tumors. NAPI-2B is found in approximately 95% of ovarian and 85% of non-small cell lung cancer, with anti-tumor activity being demonstrated in patient-derived cell lines and growth inhibition in DD spheroid non-small cell lung cancer models. The bystander effect of the TOPO1 payload may help address NAPI2B heterogeneity across different cancers. The overall differentiated design of ZW220, featuring our TOPO1-based payload with moderate potency and mid-ranged R, we believe will overcome issues associated with prior ADCs targeting APU2B. CW251, a potential first-in-class ADC molecule designed for the treatment of glapikin-3 expressing hepatocellular carcinoma, which incorporates the same ZymeWorks proprietary bystander active topo1 payload utilizing 191 and 220, with a DARA4 with selected balance tolerability and efficacy. with ZW251 anti-tumor activity observed in multiple patient-derived xenograft models of HCC, reflecting a range of GPC3 overexpression. GPC3, a GPI-anchored cell surface oncofetal antigen, is overexpressed in most hepatocellular carcinoma patients and displays minimal normal adult tumor expression, making it an appealing ADC target. We are encouraged by published research demonstrating the potential of GPC-3 targeting antibody in HCC patients as evidence by tumor localization of iodine radio labeled chondrotuzumab, a prior clinical stage anti-GPC-3 MAP, and believe that antibody drug conjugate-based targeting of GPC-3 could enable a novel and effective approach to treatment of hepatocellular carcinoma. Our ADC design holds strong promise for clinical efficacy leveraging a payload derived from a validated class of toxins, specifically campathicin, incorporating a known linker, the MCGGFG-based linker. This strategic approach capitalizes on the established efficacy associated with the chosen toxin class, ensuring a solid foundation for potential therapeutic success. Furthermore, the utilization of a known linker enhances the predictability and reliability of our ADC's performance, providing confidence in its potential clinical utility. By combining these elements in 191, 220, and 251, we believe we are poised to deliver a robust therapeutic solution to address unmet medical needs across various tumor types. These three candidates, along with our 2 plus 1 mesothelin-targeting bispecific T-cell engager, ZW171, featuring a novel the anti-CDC specificity, provide us with multiple data catalysts in the next 24 months to showcase our innovative and differentiated approach. We look forward to sharing insights from our preclinical and clinical development at medical conferences throughout the year, including AACR, where five abstracts have been accepted for presentation. Abstracts accepted from our multi-specific antibody therapeutics team include two presentations focusing on our Tri-TCE CoStim platform, a next-generation tri-specific T-cell engager platform with integrated CD28 co-stimulation, for which we will present data both on the platform itself and in the context of two tumor targeting antigens, CLODN18.2 and DLLL3, highlighting enhanced mechanistic and anti-tumor activity over clinical benchmark CD3 bispecifics, targeting the same antigens and also showcasing the versatility of the platform. From our ADC team, abstracts include updated data on ZW191, our folate receptor alpha targeting antibody drug conjugate, showcasing strong preclinical activity across multiple folate receptor alpha expressing indications. We will also be sharing progress we have made on designing and functionally screening panels of bispecific ADCs to identify those optimally formatted to overcome challenges associated with individual tumor target heterogeneity. Lastly, for our ADC abstracts of AACR, we will also be presenting data on the development of 3D cancer cell line spheroid models for the in vitro functional characterization of cytotoxic antibody drug conjugates to enable the molecule selection. In addition, Xanadidimab Zobidotin remains ready for a Phase II clinical trial in combination with Pembrolizumab at a Our P2D of 2.5 mg per kg every three weeks, based on data from the Phase 1 clinical trial. However, the initiation of the planned Phase 2 study has been deprioritized, pending more clarity from the evolving clinical landscape. We continue to explore potential development and commercial collaborations for Xanadabab Zolidone. We look forward to continuing to share our progress at additional conferences, as well as nominating our final product candidate in our 5x5 portfolio this year. Looking ahead for 2024, as Chris touched on earlier in the call, we view Zana DataMap as a near-term de-risk value driver for the company, with the BLA for BTC expected to be completed in the first half of the year by our partners, JAS. Following on from this, we look forward to the continued development of Zana DataMap for first-line treatment of BTC with the confirmatory trial initiated by JAS. Behind us are partners Beijing, are also expected to submit their BLA with the NPA in China for treatment of HER2-amplified inoperable and advanced or metastatic BTC in the second half of the year. Outside of BTC, we also expect to share the pivotal Phase III data readout for XANA data map in GEA for the Horizon GEA-01 study targeted for late 2024. Our partners, JAS, are hosting an R&D day focused entirely on XANA data map on March 19th where you can hear more about their development plans for Xanadatamab ahead of a potential launch for Xanadatamab in second line BTC in the USA during 2025 or earlier. On our earlier stage programs, we're in track to advance our development plans for our unique differentiated product pipeline with two IMDs for our mesothelin targeting bispecific antibody ZW171 and our folate receptor alpha targeting TOPO1 inhibitor-based ADC ZW19. We are also on schedule to nominate our fifth IND candidate later this year, which we anticipate being a tri-specific T-cell engager. Beyond these near-term milestones, we are continuing our IND-enabling work for our NAPI2B TOPO1-based ADC for ZW251 for GPC3-targeting TOPO1 ADC, both on track for anticipated IND submission in 2025. We are very fortunate at DesignWorks to have a wealth of experience in proprietary technology, which provide the foundation for continuous innovation for our next generation of candidates for ADCs, multi-specific antibody therapeutics and beyond. We look forward to talking more about how we can leverage our clinically validated technologies and harness the flexibility of our proprietary platforms as a foundation to solve biological challenges new mechanism mechanisms action at our r d day planned for the second half of this year despite the accelerated development of our pipeline we've maintained our strong financial position and remain financially disciplined with projected cash resources to support operations into the second half of 2027. we feel very comfortable with this cash run when we have to be able to support our r d initiatives we will continue to evaluate opportunities to broaden or accelerate our development efforts through the formation of strategic partnerships and collaborations. We're excited for what comes next, both with SANA DataMap as top-line data becomes available and as it moves through the process of potential regulatory approvals initiated by our partners, JAS and Beijing, and for our early-staged assets as they head into the clinic. With that, I'd like to thank everyone for listening. And I'll turn the call over to the operator to begin the question and answer session.
Operator? Yes, we will now begin the question and answer session.
To join the question queue, you may press star then 11 on your telephone keypad. You will then hear an tone to acknowledging your request. If you're using a speakerphone, please pick up your handset before pressing any keys. To withdraw your question, please press star 11 again. We will pause for a moment as callers join the queue.
One moment for our first question.
Our first question comes from Stephen Willey from Stifel. Your line is open.
Yeah, good afternoon. Thanks for taking the questions. I guess maybe just to start, can you just perhaps expand a little bit on the deprioritization of Zannie, Zibido, and I guess, what specific clarity are you looking to gain here from the clinical landscape before you make a firm no-go decision on whether to move forward with the phase two? Then I'd set the follow-up.
Yeah, let me take that, Stephen. So I think, you know, look, I think two years ago, we didn't have an R&D portfolio to manage, and now we do, which is now comprised of the 5x5 programs and Zannie Zhou. And we need to get good and disciplined about being able to manage priorities within the portfolio as well as the individual programs. And I think there's two reasons we need that skill. One is we need to be able to take advantage of opportunities to accelerate individual programs within the pipeline where we can. And as of right now, we have no higher priority than to try and accelerate our next two programs in the clinical studies this year and get momentum in the dose escalation. stage of those programs. So if we have an opportunity to potentially move up and accelerate ZW191, our folate receptor alpha ADC, and ZW171, our mesothelin 2 plus 1 T cell engager, and if that takes a little bit more time and focus and attention to do that, then we need to be able to shift to take advantage of those opportunities. And we definitely see the potential for that. So that's the one thing we will do now. In addition to this, we're definitely committed to the targeted therapy space in non-small cell lung cancer. That's why we have three or four programs in that area. But specifically in the HER2 targeted space, there has been a couple of external developments that we need to reflect on. One is, as you're aware, there is a competitive program that's now in front of FDA for review, which could have the potential to get a label on a part of the clinical population we were hoping to study with our planned phase two study. So I think we do want to see if we can get clarity on that with a regulatory action from FDA, which likely isn't that far away. In addition to that, there was some recently reported data on an ADC against a different target, which claimed to have some benefit in the HER2 low population in non-small cell lung cancer, which is an important part of the future commercial opportunity. So I think when we have internal data, or in this case, external events, happen, I think it's a good discipline for us to pause to get clarity and just to make sure that we can both execute the clinical development plan that we had outlined for this specific program and also to make sure that the commercial opportunity at the end of that clinical development program is still intact. And so I think this is a situation where we see both at the same time. There's an opportunity to potentially accelerate two of our programs. We should see if we can do that. and at the same time pause to get some clarity on some external events, which is not a long time period away. And I think that's a discipline that the company has to have. It has to have the ability to exercise that on an ongoing basis as this portfolio advances and grows with more compounds. And this is really the first time we're doing it, but I think we need to make sure that we're disciplined at this. And I think given both of those things, we will look forward to reporting you know, as soon as we can on the outcomes for both of those resetting priorities, both the potential to accelerate certain programs and pause near clarity on another program. It's a skill we need to be good at and exercise as often as we think is necessary with either internal data or with external events. And I think hopefully it's the responsible way to manage a portfolio and we'll continue to do this as we go forward.
Okay, that's helpful. And then just with respect to ZW171, can you just talk a little bit about the pace of dose escalation you'll be pursuing in the clinic? I guess the level of confidence that you have in the step-up dosing regimens that you'll presumably be implementing in the protocol, and then just how you're thinking about the incidence rate of grade 3 CRS that you're willing to tolerate. Thanks.
Okay, thanks. Paul decide how much of that he'd like to answer. So go ahead, Paul. Good question.
Yeah, sure. No, for sure. Great question, Steve. And right now, we're developing a clinical protocol. I can't really get into too much specifics on that. But what we've really spent a lot of time thinking about the design, or the team has spent a lot of time thinking about the design of this molecule to essentially overcome the limitations or the challenges that you mentioned. So, first of all, we are using low affinity CD3 that is a novel proprietary anti-CD3 that we feel from its properties that we've looked at in preclinical studies, you know, balances the level of activity with cytokine release. We've also implemented, you know, the structure of the molecule such that we're really trying to target the higher expression tumor cell population than the sort of low-level mesothelin expression that could be on normal tissue using the 2 plus 1 design. And that, you know, we really screened empirically for that particular 2 plus 1 design. So I think we've done everything we can preclinically to sort of de-risk the program and the design. then as we move into the clinic for sure you know we have you know we can take advantage of a lot of prior uh programs of you know t-cell engagers wire that into our design and you know be ready for you know if we do see cytokine release we'll be ready for it but again we're hopeful that through the design that we will we will limit that and allow us to be able to dose this molecule to a dose where we can get anti-tumor activity and efficacy that's not really been seen so far with mesothelin-targeted T-cell engagers.
Okay. That's helpful. Thanks for taking the questions.
One moment for our next question. Our next question will come from the line of Akash Tiwari from Jefferies. Your line is open.
Hi. This is Phoebe on for Akash. I have a couple questions. First, from the AACR abstracts, we noticed that you were going into a DLL3 targeting tri-specific T cell engager and small cell lung cancer. So just first, why are you interested in this target? And can you talk about how you think this will hold up versus other competitors like Harpoons, which showed ORR of 48% in relapse refractory? And then also, we've seen significant safety concerns for other CD28 assets. How much confidence do you have that yours can avoid or mitigate these AACs? And lastly, what sort of PFS signal do you want to see at the end of the year with Horizon GEA01 so that you feel comfortable that you'll hit on OS? Thank you.
Thank you. I think for the third part of your question, you know, I think the statistical design is publicly available for the PFSM points. You're welcome to look at that. I think based on what we saw in Keynote 811 from the TRAS plus chemo arm, we feel very comfortable with the the design with respect to PFS. Obviously, earlier this year, you saw the announcement from JAS guiding that they were adding 200-odd patients to the OSM point, but not to the PFS endpoint. So, that shows that we feel reasonably confident in the design of the study right there. And I think beyond waiting until we get the data later this year and release that data, we won't be able to comment on your last question. And I think for the first two parts of your question, I'll I'll pass it over to Paul, and he can decide how much of that he would like to answer.
Yeah, thanks, Ken, and thanks for the question. So, yeah, so what we'll be presenting is this data using our CD3, CD28 tri-specific, so it's a one-arm CD3, one-arm CD28, and then one-arms a tumor antigen, and as you correctly pointed out, one of those molecules is targeted to DLL3, and we'll be sharing data on that. The attraction of that target for us is that it has obviously had clinical benefit with bispecifics, but we feel that gives us a nice benchmark in which to compare our program to. So there are the bispecifics. What additional benefit do you get from adding in CD28? And I think what we'll show is that preclinically, we do see you know, the benefit of adding, you know, the co-stimulation, and we can enhance efficacy while balancing what was very important for us in the design of this molecule was balancing the potential for any sort of T cell activation independent of engagement with the tumor antigen. And our engineering team spent a lot of time working on that, working on the position of the CD3, CD28, so that we only get CD28 activation when we get engagement with the tumor antigen and engagement with the CD3. So that really we think can overcome some challenges that you see with CD28 by specifics where that sort of dependence of the first engagement of CD3 is not there. So that, we really are excited about that. We feel that we've got the right sort of balance there. And now we will test against DLL3 with the idea being that we can then benchmark that, at least at this point, pre-clinically against clinical stage-by-specifics, and we'll share some of that data at the AACR.
Thank you. One moment for our next question. Our next question comes from the line of Yago Nikamovic from Citigroup.
Your line is open.
Yeah, hi. Thanks. Hi, Ken and team. Just a question on the five new INDs. Obviously, a heavy focus on the TOPA-1, and you haven't yet disclosed the fifth one, the IND in 2026. Any broad thoughts there in terms of whether that's going to lean more towards another TOPA-1 ADC, or you'd go in the CD3 direction, or potentially something else? Thanks.
Yeah, good question. You know, I think we have three ADCs going in the clinic the next two years that are all with our proprietary 519 payload and our philosophy of great antibodies and designing stability in the linker. So I think in those polar receptor alpha, the NAPI-2B and GPC-2B, we feel comfortable that that proves our ADC engineering capabilities against those targets of that payload. And I think we do like the diversity of being both companies who can engineer next-generation ADCs, but also take bispecific further, which we do in a format which is TRI-specific. And so, I think we like the 2 plus 1 mesothelin-targeted TCE, and I think we'd like to earmark for the fifth one, although we've not nominated that yet, but we'll do so during the course of this year, to reserve that for the potential to show the TRI-TCE capabilities that Paul has described. I think that's what we'd like to do. So we would expect that that five by five program ends up being three ADCs and two C-cell engagers so that we can show the capabilities of the companies on both sides of the R&D lab that we work in and will all be good individual agents on their own. Interesting targets still remain very therapeutically focused in the three areas that we seem to be concentrating on, which is thoracic, which can be non-small cell lung cancer or small cell or eventually HNCC in gynecological cancer, where we tend to focus on ovarian and endometrial cancer at the same time. And then the third area, GI, which uses our GI experience from ZANI, which obviously you can see we're adding HCC to that with 251, and eventually hope to add other opportunities in pancreatic and colorectal. So it'll be strictly in those therapeutic areas. likely a tri-TCE, but we have not named it yet and we'll do so later this year.
Okay, thanks. And then just more from a strategy perspective, as you embark on these five INDs, you know, how are you thinking about the development here? Will you take each of these forward to a certain point independently and then consider external opportunities? Or are you going to take them all forward full force in late stage development yourself? Obviously, it's early and a lot of questions aren't answered, but is there a high level view as to how you might plan forward with this portfolio of five new INDs in terms of maintaining the rights versus partnering? Thanks.
Yeah, I think the capital plan we put together post the jazz deal provided the bandwidth to take five new agents as we're doing into clinical studies and to get phase one data to understand clinical validation of what we had thought was a good scientific thesis and developed pre-clinically. So we definitely have the bandwidth and the capital plan to do that ourselves. And I think we've constructed a very good global early stage development group, which allows us to focus on doing that in a very nimble way with all five of those programs with a high percentage of the patients being recruited outside the US, which we think makes it quicker and it is less expensive in the capital plan to do that. So I think we have the bandwidth to do that, but it's obvious to everyone that the interest in novel antibody drug conjugates, especially with the proprietary payload we have and the philosophy we have is of keen interest to potential partners looking to expand in that area. And I would say T-cell engagers that are novel, like the ones that we have with both the 2 plus 1 format and the CD28 co-STEM factor are both of interest as well, a growing interest among potential partners. So we need to move forward on our own because we have the ability to do that and get clinical data on all five of those. But I think there are opportunities and will continue to be opportunities for us to see the value in potentially partnering on one or more of those programs earlier than clinical data being available. And we continue to have those discussions and understand how that interest can help us broaden out our programs, accelerate them, monetize a good value for some of the work we've done, share risk with partners. And so we'll continue to do that while we execute this clinical development program that we've set out with the five new INDs over the next period of time.
Thank you.
One moment for our next question.
Our next question comes from Brian Chang from JP Morgan. Your line is open.
Hey, guys. Thanks for taking our question. On CW191, can you talk about your latest thinking about the phase one trial design specifically, you know, especially around the fully receptor alpha expression How wide-ranging could we expect in terms of the expression in the first study? And then I have a quick follow-up. Thank you.