CytomX Therapeutics, Inc.

Good afternoon, everyone. Thank you for standing by. Welcome to the Cytomics Therapeutics first quarter 2026 financial results call. Please be advised that today's conference is being recorded. I would now like to hand the call over to your host for today, Chris Ogden, Cytomics Chief Financial Officer. Please go ahead.

Thank you. Good afternoon, and thank you for joining us. Before we begin, I would like to remind everyone that during this call, we will be making four looking statements. Because forward-looking statements relate to the future, they're subject to inherent uncertainties and risks that are difficult to predict, and many of which are outside of our control. Important risks and uncertainties are set forth in our most recent public filings with the SEC at sec.gov. We undertake no obligation to update any forward-looking statements, whether as a result of new information, future developments, or otherwise. Earlier this afternoon, we issued a press release that includes a summary of our first quarter, 2026, financial results, and highlights recent progress at Cytomix. We encourage everyone to read today's press release and the associated materials, which have been filed with the SEC. Additionally, the press release, recording of this call, and our SEC filings can be found under the investors and news section of our website. With me on the call today is Dr. Sean McCarthy, Citomix's Chief Executive Officer and Chairman. Sean will provide an update on our pipeline and company progress before I cover the financials for the quarter. We will then conclude with a Q&A session. With that, I'm going to turn the call over to Sean.

Thanks, Chris, and good afternoon, everyone. We're very pleased to be here today to provide an update on our first quarter developments and guidance for what's continuing to be a transformational year for cytomics. 2026 is also a very exciting start, driven by our excellent clinical progress with Varsetta-M in late-line colorectal cancer. Varsetta-M is a first-in-class EPCAM-targeting antibody drug conjugate, or ADC, that was uniquely designed and enabled by our proprietary pro-body therapeutic masking platform. Varsetta-M is the only EPCAM-directed ADC in clinical development, to our knowledge, affording us a strong lead and a powerful competitive advantage. EPCAM is one of the most abundant solid tumor surface antigens, and Cytomix's breakthrough in unlocking EPCAM as an ADC target positions Varsetta M as a company building asset over the near and long term. We see multiple layers of value creation potential for Cytomix through the advancement of Varsetta M. In colorectal cancer, which I'll now refer to as CRC, our goal is for Varsetta to become a core component of the standard of care, including in early aligned therapy. Metastatic CRC remains one of the largest areas of unmet need in oncology today, which really underscores the urgency we feel at Cytomix to progress Varsetta M towards the market as rapidly as possible. Commercially, in the late line setting alone, this represents a multi-billion dollar market. In addition to the very substantial opportunity in CRC, we also plan to capitalize on our leadership in EPCAM targeting by developing Varsetta M in other cancers and ultimately as a pan-tumor therapy. Varsetta has the long-term potential to positively impact the lives of so many people with cancer, and we are focused on executing with urgency to rapidly progress this potential therapy to regulatory approval. Cytomix has made a very strong start in the clinic with Varsetta M. In our most recent phase one data update in March this year, we shared updated efficacy data in late line metastatic CRC showing a confirmed overall response rate between 20 and 32% and approximately seven months of median progression-free survival. These data position Varsetta as a potentially transformative step forward in the treatment of metastatic CRC, where currently available therapies offer overall response rates only in the low single digits and just a few months of PFS. Varsetta M is working exactly as designed, and it's unlocking the true potential of Epcam for the first time. With Varsetta, Cytomix is bringing the power of the ADC class to colorectal cancer. I want to really underscore here that we've achieved something very significant with our ProBody platform technology. In our view, and based on our preclinical data and efforts of others over many years, we believe we can say with confidence that a conventional, unmasked ADC targeting Epcam would have no chance of achieving dose levels that deliver meaningful anti-cancer activity due to severe on-target toxicities. In contrast with Varsetta M, we have achieved remarkable anti-cancer activity in one of the hardest to treat cancer types. We firmly believe we have done the hardest experiment first by focusing initially in CRC and that the best is yet to come. In terms of key near-term objectives for Varsetta M, we are currently in dose optimization with the goal of advancing into a registrational study in late-line CRC in the first half of 2027. Today we're very pleased to share that we have completed enrollment in the ongoing dose optimization cohorts with 40 total patients now enrolled across the 8.6 and 10 milligram per kilogram doses, taking total enrollment across the phase one study to 113 patients. We remain well on track for an update before the end of this year as we work towards prioritizing one of these two doses of this highly active drug candidate for our first pivotal study. In evaluating the potential registrational study dose, we're focused on optimizing the risk benefit of Varsetta M, building on the significant learnings in the dose escalation, expansion, and optimization phases. Regarding Varsetta M safety, we have been highly encouraged by the preliminary results we shared in March from dose optimization that show that updated patient management strategies have the potential to substantially reduce the rate of high-grade diarrhea we saw earlier in Phase I development. This is the principal adverse event of interest with Varsetta, and it's something we feel confident we can get an increasingly well-developed understanding of as we move forward through the optimization cohorts and beyond. Typically, patients respond very well to management, And our overall discontinuation rates are low, accounting for the impressive progression pre-survival data we have shared to date. In terms of our next clinical communication, we expect to provide an overall phase one data update, including safety and efficacy from the monotherapy dose optimization in the second half of this year. We expect these data, along with FDA interactions in 2026, to inform Varsetta-M monotherapy dose selection and the first registrational study design. Our primary goal with Varsetta M is initially to develop in the late line where we see this drug candidate as highly differentiated and, frankly, as offering a highly impactful new option for CRC patients. Over time, our vision for Varsetta in CRC is to replace systemic Irinotecan in the treatment paradigm and potentially to displace chemotherapy entirely. Accordingly, and in parallel to its development as a monotherapy in CRC, we are aggressively advancing Varsetta M into combination studies to enable earlier line utilization. Strategically, we see an enormous opportunity for Varsetta in early line CRC. To access this opportunity, we have initiated a combination with Bevacizumab as a first step to moving Varsetta into earlier line therapy. Anti-VEGF antibodies, including bevacizumab, are extensively utilized in early and late-line CRC treatment, so this will be a foundational combination. Parsetta M doses assessed in combination with bevacizumab will include both every two weeks and every four weeks schedules to align dosing with the approved five mg per kg every two weeks schedule, standardly used in the clinic today. We expect initial clinical data for this combination by the first half of 2027. We're also accelerating plans to study Varsetta in combination with chemotherapy, and we plan to begin a Phase I-II chemotherapy combination study in the second half of 2026, evaluating Varsetta in combination with Bevacizumab, bifluorouracil, and leucovorin with the potential to advance into the first and second lines. In addition to our work in colorectal cancer, we are on track to begin phase one expansion cohorts in additional EPCAM expressing indications in the second half of 2026. We look forward to providing an update on the initial non-CRC indications later this year with the goal of generating clinical data supporting Varsetta's ultimate pan-tumor potential. Turning now to CX801. our masked interferon alpha 2B program, which is currently in phase one development for advanced checkpoint refractory melanoma. Our vision here is for CX801 to become a new centerpiece for combination cancer immunotherapy as we harness and redirect the power of this cytokine to reprogram and activate anti-tumor immunity. We initially see CX801 as well-positioned to address the higher need in PD-1 refractory melanoma, where response rates to approved standard of care remain in the single-digit percentages with limited treatment options available or in clinical development. Interferon alpha-2b is a potent cytokine that has validated clinical activity in melanoma and other cancers, And our initial translational data from phase one suggests that CX801's mechanism of action is working as designed in the tumor microenvironment. Importantly, our data shared at CITC in 2025 are highly supportive of our strategy for combining with the checkpoint inhibitor Keytruda. Our ongoing CS801 phase 1 monotherapy dose escalation study has advanced to the fourth dose level, which exceeds the approved clinical dose of unmasked interferon alpha 2B. CS801 has been well tolerated to date, suggesting that our masking strategy is broadening the therapeutic window as designed. Combination dose escalation with Keytruda is also progressing very well and is now actively enrolling in the third dose level. Overall, we view CX801 as very well positioned to address a significant unmet need in advanced melanoma, and we look forward to sharing initial clinical data by the end of this year. With that, I'll now transition back to Chris.

Thank you, Sean. Reinforcing Sean's earlier sentiment, we kicked off 2026 from a position of strength, not only with Varsetta M's encouraging data, but with the financing completed in March, a strong balance sheet that enables us to continue to execute against the significant value creation potential of Vercetta and the Probody platform. Syctomics is in a strong financial position with projected cash runway to at least the second half of 2028 and the potential to achieve multiple milestones. Of note, our runway guidance does not include any supplemental milestones from existing collaborations or any new business development. Importantly, we expect our current cash position will enable us to advance Varsetta M into a registrational study in late-line CRC, also deliver safety and efficacy data for Varsetta M in combination with Bevacizumab, as well as Varsetta M data in combination with chemotherapy, and deliver initial clinical data for Varsetta M in indications beyond CRC. Based on these opportunities, which have the potential to yield significant long-term commercial potential, We expect our capital allocation to be highly focused on Varsetta M over the near to medium term. With that, I'm going to walk through our first quarter financial results. As of March 31st, 2026, we ended the quarter with $346.7 million in cash, cash equivalents, and investments versus $137.1 million in cash as of December 31st, 2025. Looking at revenue and operating expenses for the quarter, total revenue was $10.3 million compared to $50.9 million in the first quarter of 2025. The decrease in revenue was primarily attributed to the completion of obligations in 2025 under collaborations with Bristol Myers Squibb and Amgen. Operating expenses for the first quarter were $29.8 million compared to $28.3 million in the first quarter of 2025. R&D expenses were $19.2 million during the first quarter, representing an increase of $0.4 million versus the first quarter of 2025, primarily due to increased manufacturing activities for Versetta N, partially offset by $1.8 million in restructuring expense incurred in the first quarter of 2025. G&A expenses increased by $1.1 million during the three months ended March 31, 2026 to $10.6 million compared to $9.4 million for the corresponding period in 2025, which included $1.1 million of one-time restructuring expenses. As we move throughout the remainder of 2026, we will continue to be disciplined in our capital allocation and advancing the highest Varsetta M priorities for patients and cytomic stakeholders. With that, I'll turn the call back to Sean for closing remarks.

Thanks, Chris, and thanks, everyone, for joining us today. We're very proud of the remarkable progress we've made with Varsetta M, and we're now in the privileged position of bringing the transformative potential of an EPCAM-directed antibody drug conjugate to colorectal cancer patients. We look forward to providing additional updates as the year progresses and as the development program for Varsetta M broadens substantially. We also remain focused on the advancement of the clinical program for CX801, with the initial goal of delivering a more effective treatment option for patients with advanced melanoma. Before I conclude today's call, I want to sincerely thank and recognize the patients who join our studies, their families, our clinical investigators, and our dedicated cytomics team. With that, operator, let's go ahead and open up the call for Q&A.

Certainly. As a reminder, to ask a question, please press star 11 on your telephone and wait for your name to be announced. To withdraw your question, please press star 11 again. Please stand by while we compile our Q&A roster. And our first question will come from Paul Jing of Guggenheim. Your line is open, Paul.

Thanks for taking the question. So for Vercetta, can you just talk a little bit about the scope of the clinical update you'll have in the second half? You know, will some or most of the dose optimization cohort patients have sufficient follow-up for PFS? Do you plan to break down responses by subgroups such as, you know, third-line versus fourth-line positive therapy? And then how are you thinking about initial disclosures of overall survival from the study? Thanks very much.

Yeah, thanks, Paul, for the questions. So we are expecting that the update in the second half will be fairly substantial. As we've mentioned today, we've now enrolled 113 patients across the dose escalation, expansion, and now optimization phases of the study. So this is a very rich data set that is emerging for our first evaluation of Varsetta in CRC patients. So in terms of the update, it will be across the entire study. It will include data from the full 40 patient optimization phase. And, yeah, we expect to have a reasonable follow-up in terms of safety and efficacy for the optimization patients, including, I would think, an initial estimate of PFS. As you'll recall, last year, our guidance as we came through the second half of 2025 was that we wanted to communicate data this year when it was mature and meaningful, and that continues to be the case and continues to be our philosophy. In terms of subgroups, yeah, we'll certainly communicate the demographics of the patient population that we're enrolling. We do expect it to look quite similar to the patient population that we enrolled in the escalation and expansion phases. And I want to emphasize that one of the really differentiating and distinguishing features of Varsetta M as a drug for colorectal cancer is that we can treat every patient. We're not selecting patients. We don't need to select patients. This really is a drug for all-comer, late-line CRC. And we see this as potentially a huge competitive advantage as we move the drug toward the market. In terms of the third component of your question and overall survival, yes, we absolutely anticipate having or providing, if you like, a first look at OS in this update in the second half of the year.

Great. Thank you very much.

Thank you. And our next question will be coming from the line of Edward Tintoff of Piper Sandler. Your line is open, Edward.

Great. Thank you very much. And I'm really excited for more data looking in the back half I just had one quick clarification question on the one-two chemo combo. Will that be triplets or will you have Avast or I guess quadruple with the two chemos? And will that include Avastin? And do you need any of the Avastin combo data to start that? you know, chemo combo trial. I just want to make sure I understand that correctly.

Yeah. Hi, Ted. Thanks for the question. Taking the first question first in terms of the nature of the combination, yeah, we absolutely will want to evaluate the Varsetta M plus chemo plus Bev. combination. We will want to look at that. Right now, we don't see the data from the ongoing Varsetta M plus Bev as gating necessarily to starting that work in the second half. We do, of course, see that that BEV combination work, the Varsetta-M BEV combination is going to be really important to further down the road, considering from a registrational study perspective, the design of that study, if indeed we do at some future point decide to compare Varsetta-M plus BEV against other comparator arms. But we do plan to look at that triplet in the chemo combination later this year.

Yeah, and then that's really helpful. And then when it comes to the new Epcam-positive tumors, I'm really excited to hear what your thinking is. Maybe you can share with us now kind of what goes into some of that prioritization, because there's a lot of different places you could go.

Yes, there are so many places we could go because EPCAM is such a broadly expressed cancer target on so many solid tumors. So we do have a lot of opportunities to work through and prioritize. It's not lost on us, of course, or really anybody else, that there's quite a number of, if you like, adjacent GI tumors that can make a lot of sense to evaluate. With Varsetta M, there are also many others. So something that we continue to work through and prioritize, and we will communicate more specificity on exactly what we're planning to do in the second half.

Great. I'm looking forward to it, and more data. Keep up the great work.

Thanks, Ted. Of Anupam Rama of J.P.

Morgan, your line is open.

Hey, guys. This is Joy Son for Onupon. Thanks so much for taking our question. I think previously you had said you were targeting mid-year FDA interactions to start discussing the PIVO trial design. To what extent is reaching alignment on the trial design ultimately gated on seeing your dose optimization update later this year? I assume you can start having those conversations with FDA now with your initial data in hand. But just how should we think about the update later this year in terms of solidifying a registration strategy? Thanks.

Yeah, thanks. Great question. Really important question. And I'll start by saying that we're just really excited to have this dialogue with FDA as we progress through the year. We anticipate multiple interactions. And we do expect that the data from the optimization cohorts will be central to those conversations in relation to dose selection for the first pivotal study. That's, of course, a large part of the reason we're doing these additional two N equals 20 cohorts at the 8.6 and 10 mcg doses is to generate data to satisfy project optimists. and have as highly productive a conversation with FDA as we can. So, yes, that data will be important, and that's why we're guiding that really towards the end of the year, or by the end of the year, the next comprehensive update that we plan to provide will not only include, of course, data across the 113-patient Phase 1 study, but will also include guidance as to where we're going next in terms of design of the first pivotal study, what the patient population is, what the comparator arm is, and of course, what the dose is.

And our next question will be coming from the line of Roger Song of Jefferies. Your line is open, Roger.

Hey, thank you, team, for taking our questions. Congrats on the progress. This is Nabil on for Roger. Maybe one for me first. So just on the 8.6 versus 10 mg per kg, just a little bit curious if you could maybe give some color on the dose decision logic, because we saw the headline OR 32% versus 20%. But what is the framework that you guys would apply to finally lock in on a dose? Is it related to tolerability at this point? We notice in the exposure response model, it looks like there's pretty similar efficacy. So are you weighing depth and durability? Are you weighing safety more?

Thank you. Yeah, thanks, Nabil. That's obviously, there's a lot in that question in terms of the work that we are doing in real time and will be continuing to do as we move through the year to lock in on the go-forward dose. And the first thing I'll say is we think we've got two great choices here in terms of the 8.6 and 10 Mg per kg doses, both of which, as you'll recall, we're currently evaluating on an adjusted ideal body weight basis in the context of the dose optimization cohort. So we're going to learn a lot as the year goes by as to the performance of these two doses, of course, in terms of efficacy, also in terms of safety. On efficacy specifically, as we've been discussing for quite some time now, we do anticipate that at least our base case for our first registration study, we do anticipate that overall survival will be our primary endpoint. And that, of course, means that ORR is really an important metric here for how the drug's performing, and this drug is performing extraordinarily well. As you said, 20% ORR at 8.6, 32% at 10 MPK. That is remarkable activity. But we also have remarkable progression pre-survival of seven months, as reported on March 16th, and we are very keen to see how that translates into OS as the data matures. With OS, of course, as I just mentioned, being our primary, most likely primary, in the go-forward pivotal study. So, you know, we'll see. We'll see how these two doses deliver in terms of all of these different metrics, and we'll choose accordingly.

Excited to see that as well. Thank you. You're welcome.

And our next question will come from the line of Olivia Breyer of Cantor Fitzgerald. Your line is open, Olivia. Yes.

Hi, good afternoon. Thank you for the questions. For that second half data disclosure, can I just clarify that you guys plan to break out tolerability and efficacy for those 40 patients specifically in the optimization cohort? And if so, will we still get PFS and potentially even an early look at some OS data from those patients specifically? From a timing perspective, top line, second half of this year, does that mean you'll likely follow it up with a presentation at a medical conference sometime in early 2027? And then I've got one quick follow-up on the new formulation with Bev.

Yeah, thanks, Olivia. So yeah, obviously, the 40 patient optimization cohorts is of high interest to us and others. And so we absolutely plan to report the full safety picture, which we gave an early look at in the March 16th disclosure. We gave an early look at the first two months of experience, which is very encouraging. So we plan to give a similar look for the full 40 patients by the end of the year, together with efficacy. And as I've already mentioned, PFS would certainly be a goal there to have PFS for those 40 patients. I think OS is going to be too early. As we've reported today, we've completed enrollment, but that's been relatively recent. So I think OS is going to be immature. But we do anticipate having OS from the escalation and expansion phases, which I think will be particularly telling. Because remember that in those patients, those first escalation and expansion patients, we have not optimized our adverse event management plan, but we were still able to deliver seven months of PFS and we're optimistic that we'll have an encouraging OS number as we get to report that later in the year. In terms of venue for data updates, we do think a medical meeting this year is on the cards. Certainly as we move into 2027, additional medical meetings, we're of course keeping our options open.

Okay, very helpful. And then for the combination with Bev, is there anything you guys can tell us at this point about the formulation work that you've done to get Varsetta M administered as an every two and four week dosing schedule instead of every three weeks? Or is there any data that you'll be sharing there at some point?

Well, there's no real formulation work that needs to be done. It's simply an adjustment of the schedule from Q3 to Q2 and then accordingly to Q4. And that's to match the As I just mentioned on the call, that's to match the established clinical use of Bev in the Folfox, Folfuri setting on a two-week schedule. So there's no additional formulation. It's simply a question of adjusting the frequency of dosing to match the use of Bevacizumab in the marketplace today.

Okay. Thanks, Sean. Appreciate it.

You're welcome.

And our next question will come from the line of Matt Bigler of Opco. Your line is open, Matt.

Hey, guys. Thanks for the question. I'm just kind of curious how you're seeing the emerging competitive profile here for SETA-M versus the other ADCs that are also in development, PressMTCT being one of them. And then, I guess, more importantly, do you think this is like a winner-takes-all zero sum game here with the topo one base ADCs, or do you think different patients might get different ADCs depending on, you know, certain health status, et cetera? Thanks.

Thanks, Matt. Well, we certainly don't see this as winner takes all by any means, and I think that would be a very unusual scenario for an oncology drug in this class. in an area of unmet need like this. I mean, our thinking is very different on that question. So, first of all, with regards to Varsetta M, we have a first-in-class anti-EPCAM antibody drug conjugate. And again, I really can't emphasize how important it is to realize that we've done something really, really, I'll use the word special, with our technology to unlock the potential of EPCAM for the first time with our ProBody therapeutic platform. Secondly, we really do believe that Varsetta M has the potential to be the best in class ADC for colorectal cancer. This drug is highly active. It's highly active in terms of its response rate. It's highly active in terms of its progression pre-survival, and we'll see what it can deliver in terms of overall survival as we move forward. This is a very active drug, and we believe does have the potential to be best in class. So we're We're going all out with this drug to get it to the market as quickly as we can. We think it's highly competitive, and we think there's a ton of value to build in our company with this drug. Most importantly, an enormous amount of benefit to bring to these patients.

Thanks.

As a reminder, to ask a question, please press star 11 on your telephone and wait for your name to be announced. Our next question will be coming from the line of Mitchell Kapoor of H.C. Wainwright. Your line is open, Mitchell.

Hi. Thank you for taking my question. This is Yonzi sitting in for Mitchell. I was wondering, could you break – so, actually, with the enrollment now completing the 40-patient dose optimization core, can you give any update on whether grade 3 or higher diarrhea in the optimized – adjusted ideal body weight plus prophylaxis population is still tracking closer to that initial 10% rate that was seen in the first 20 patients, or whether it's moved closer to something like the historical 25 to 30% range at the 8.6 and 10 mg per kg as follow-up has occurred?

Well, no new data today. That data will be coming. We obviously were highly encouraged by the initial data we presented on March 16th, from the first couple months of follow-up of the first 20 patients enrolled into the optimization cohorts with a rate of grade 3 diarrhea of 10%. I think we commented at the time, and we've been very consistent about this over the last few months, that our objective is, of course, to manage the rate of grade 3 to the best of our ability with this updated AE management strategy that includes upfront use of loperamide, and budesonide. It appears to be performing very well as of that first data update, and we're encouraged to see additional data now from the full 40 patients. That data will be shared later in the year. Our goal overall is to manage the grade threes into the 10 to 20 percent range. That, we think, is really the target, and that's based on our own research. It's based on a lot of conversations we've had, and quite honestly, a lot of work has been published and presented by others over the last six or so months. So we feel we're very much on track, as I said in my prepared remarks, to get a strong handle on that particular aspect of the Varsetta-M program.

I see. Thanks. I'm curious also, so for an optimized regimen, how standardized is prophylaxis practice? Do you see any implementation friction that could matter in a community oncology setting if, for example, Varsetta M moves earlier in late-line CRC?

We really don't. The upfront work that we're doing right now with these optimization cohorts is absolutely intended to pin down a prophylaxis strategy that will be readily translated into into the community community setting as we move into our uh first pivotal study and of course as we bring the drug to the market so it's a good question it's an important question and it's one that we've asked ourselves and that is again just to restate a big part of why we're doing this upfront optimization work uh right now but we right now we don't see any challenges uh with the the translation, if you like, of this updated AE management plan into a larger number of sites and ultimately into the commercial marketplace.

Thank you so much. I'm looking forward to the next update.

Thank you. You're welcome. I'm not showing any further questions in the queue. I would now like to turn the call back to Dr. Sean McCarthy, Chairman and CEO, for closing remarks.

Thank you. And again, I'd just like to thank everyone for joining us today. We're very excited about our progress here. I hope that comes across. And we really look forward to providing additional updates as the year progresses.

And this concludes today's program. Thank you for participating. You may now disconnect.