CytomX Therapeutics, Inc.

Good morning, everyone. Thank you for standing by. Welcome to the Cytomics Therapeutics 2025 Financial Results and Faceta Phase 1 Dose Expansion Data Call. Please be advised that today's conference is being recorded. I would now like to hand the conference call over to your host for today, Chris Ogden, Cytomics Chief Financial Officer. Please go ahead.

Thank you. Good morning, and thank you for joining us. Before we begin, I would like to remind everyone that during this call, we'll be making forward-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 today, we issued a press release that includes a summary of our 2025 financial results and progress at Cytomix. Additionally, this morning, we are excited to announce positive phase one dose expansion data for Varsetta N in patients with late-line colorectal cancer. The focus of our call today will be the phase one expansion data update for Varsetta. For details on the company's 2025 financial results and other pipeline updates, we encourage everyone to read today's press releases and the associated materials which have been filed with the SEC. Additionally, the press releases, a 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 are Dr. Shawn McCarthy, Cytomix's Chief Executive Officer and Chairman, and Dr. Wayne Chiu, Cytomix's Chief Medical Officer. Shawn will provide introductory remarks regarding the clinical data and Varsetta program strategy, and Wayne will then walk through the clinical data. We will then wrap up with concluding remarks in a Q&A session. With that, I'll now turn the call over to Shawn for opening remarks.

Thanks, Chris, and good morning, everyone. It's really a pleasure to be here with you all. The major focus of today's discussion will be an exciting update on Phase 1 data for our EPCAM-targeting antibody drug conjugate, Varsetatug-Mazatecan, otherwise known as VarsetaM or Varseta. There's been a very high level of interest in this program since our first data disclosure in May last year. in which we shared a strong start with the clinical development of this first-in-class ADC for colorectal cancer. We'll refer to colorectal cancer during this presentation as CRC. In today's update, we want to share the terrific progress we have continued to make over the past 10 months. We continue to be highly encouraged by what we're seeing, and we aim to develop Varsetta M aggressively for the benefit of patients with CRC and, over time, many other cancers. In this presentation, we aim to address key questions that relate to the next steps in the development of Varsetta, specifically the drug's efficacy profile across a larger patient dataset, improving our understanding and management of gastrointestinal adverse events, and how we are integrating all of this data into future dose selection as we lock in on plans for late-stage development and registration. Okay, let's get to it. Colorectal cancer remains one of the biggest unmet needs in oncology. 1.9 million patients per year are diagnosed around the world, and that's predicted to grow to more than 3 million patients by 2040. CRC is the second leading cause of cancer death worldwide and is growing in incidence in younger patients. Five-year survival in patients with metastatic CRC is a dismal 13%. We see colorectal cancer as one of the largest untapped solid tumor markers. This cancer type has been largely bypassed by the last 20 years of oncology innovation and progress. Antibody drug conjugates have transformed the treatment of many tumors, initially hematologic cancers and increasingly solid tumors. We're seeing ADCs coming earlier in the treatment paradigm, increasingly showing opportunities to replace systemic chemotherapy in a variety of tumor types. There is no approved ADC for the treatment of CRC. Varsetta M is bringing the potential and the power of antibody drug conjugates to colorectal cancer. CRC is a very large market opportunity. In the third line setting alone, there are projected to be 45,000 addressable patients in the US by 2040, creating a multi-billion dollar potential market opportunity. And while the unmet need is greatest in the later line setting, the entire treatment paradigm for this cancer could be changed by a pan-CRC ADC with the potential to move to earlier lines of therapy like Varsetta M. The current standard of care in late-line metastatic CRC is highly inadequate. The options available today for patients result in objective response rates in the low single digits and progression pre-survival of two to five months. These agents are unfortunately the best that are currently available for the treatment of patients after they have exhausted chemotherapy-based regimens. We must do better, and I'm pleased to say we are doing better by bringing Cytomix innovation to bear on this problem. Varsetta-M was intentionally designed to be active in CRC. We carefully selected the right target and the right payload, and we have uniquely unlocked this opportunity with our ProBody therapeutic platform. Varsetta-M targets EPCAM, epithelial cell adhesion molecule, It's been known a long time that EPCAM is present at very high levels on colorectal cancer. In fact, it was first identified as a CRC marker. EPCAM is uniformly and highly expressed across all stages of the disease. There have been many efforts to target EPCAM previously. The major challenge has been it's present on most normal epithelial structures. So, approaches to target EPCAM in the past have hit significant toxicity roadblocks very early in their development because of EPCAM expression in normal tissues. Based on these prior unsuccessful efforts and as also shown by our own preclinical experiments, a conventional ADC targeting EPCAM would not be expected to be developable. Farsetta-M is designed to unlock EPCAM as an ADC target and is based on a high affinity anti-EPCAM antibody which we have masked using Cytomix protease-dependent peptide masking pro-body strategy designed to minimize binding in normal tissues. The mask is removed by proteases within the tumor microenvironment, allowing binding and engagement with the target and delivery of the effector mechanism and anti-cancer activity. The anti-tumor effector in Varsetta M is a novel TOCYS1 payload called CAP59 that we licensed from Immunogen. The linker is also novel, a trialanine cleavable peptide linker optimized for bystander effect. We now refer to this TALCAMP59 linker payload as Mazatecan. Varsetta-M has a drug antibody ratio of eight. We really believe with this drug candidate, we have the right target and the right payload with this overall strategy being uniquely enabled by the Cytomix ProBody platform. So where are we with the phase one study? Shown here is the current enrollment status. As we reported in August last year, enrollment into the dose escalation and expansion phase at that time had reached a total of 73 patients. This included 60 patients treated at the prioritized expansion doses of 7.2, 8.6, and 10 milligrams per kilogram administered every three weeks. The updated efficacy data we're sharing today is focused on these expansion cohorts for which we now have meaningful follow-up and from which we expect our go-forward dose for the first registration study will be selected. In Q4 last year, we increased enrollment into the phase one study with the goal of further dose optimization. As of a data cutoff of January 16th, 2026, enrollment across the study had reached 93 patients. The additional 20 patients enrolled are the first 20 of a target of 40 patients being enrolled in dose optimization cohorts. Dose optimization is focused on the top two doses from the expansions, 8.6 and 10 mg per kg, and encompasses adjusted ideal body weight dosing and an updated prophylaxis strategy that Wayne will walk you through shortly. Today, we'll share safety data across the full 93 patients. showing the progress we're making in adverse event management and specifically the management of treatment-related diarrhea for which we believe we are making excellent progress. We are very excited today to share updated results from the ongoing phase one study of Varsetta M in late line CRC. This drug candidate continues to perform extraordinarily well. Antitumor activity continues to be very strong with a 32% confirmed overall response rate at 10 mg per kg and a 20% confirmed overall response rate at 8.6 mg per kg. Our current estimate of preliminary progression pre-survival has improved from 5.8 months in May of 2025 to 6.8 to 7.1 months. We've also made excellent progress in understanding and managing the safety profile of Varsetta M. We continue to see no evidence of the classic EPCAM toxicities that have limited previous efforts to drug this target. And importantly, through the use of further updated prophylactic strategies, we can report today a rate of grade three diarrhea of 10% in early dose optimization cohorts. Simply put, we believe we have an important potential new treatment for colorectal cancer that has been uniquely enabled by our core platform technology. This is a major landmark for our company, and most importantly, of course, a big step forward for patients. Our top company priority is now to move Varsetta forward aggressively into its first registration study. And with that, let me hand over to Wayne to talk you through the details of the data. Thanks, Sean.