CytomX Therapeutics, Inc.

Thank you, Victor. Good afternoon, and thank you for joining us. With me today are Dr. Sean McCarthy, Cytomix's President, Chief Executive Officer, and Chairman.

Dr. Amy Peterson, Chief Development Officer, and Carlos Campoy, Chief Financial Officer. Earlier today, we issued a press release that includes a summary of our fourth quarter and full year 2020 financial results and highlights the important progress we made during the year. We encourage everyone to read today's press release and the associated materials, which have been filed with the SEC. Additionally, the press release and a recording of this call can be found under the Investors and News section of our website at citomix.com. During today's call, we will be making forward-looking statements. Because forward-looking statements relate to the future, they are subject to inherent uncertainties and risks, including uncertainties surrounding the COVID-19 pandemic that are difficult to predict and many of which are outside our control. Important risks and uncertainties are set forth in our most recent public filings with the SEC at sec.gov, including our Form 10-K filed today. We undertake no obligation to update any forward-looking statements, whether as a result of new information, future developments, or otherwise. With that, I would like to turn the call now over to Sean.

Thank you, Chow, and good afternoon, everyone. Thanks for joining us today. 2020 was a highly productive year for cytomics in spite of the COVID pandemic as we continue to execute our strategic plan to deliver on the promise of our technology platform for transforming the lives of people with cancer and building a sustainable oncology-focused commercial organization for the long term. To that end, we are well on our way as we continue to work diligently towards initial readouts in 2021 from ongoing phase two work on our lead conditionally activated antibody drug conjugates, CX2009, or Pralazetamab-Ravtanzine, and CX2029. Let me begin by reiterating that we are the leader in the emerging field of conditional activation of antibody therapeutics. Our approach, the ProBody platform, is designed to increase the exposure of therapeutic antibodies in cancerous tissue compared to normal tissue by leveraging the protease-rich tumor microenvironment. We believe that disease localization of therapeutic antibodies will be an important therapeutic concept for many years to come, and we're only at the beginning of what this approach will ultimately do. Cytomics is blazing the trail of conditional activation, and we believe this can lead to important advances in oncology, perhaps in other therapeutic areas. Cytomics has demonstrated versatility of conditional activation across multiple antibody modalities, including immune checkpoint inhibitors, antibody drug conjugates, and by specific antibodies. Our robust clinical pipeline now comprises five probody therapeutic candidates, four of which are in phase two evaluations across nine cancer types. We have purposefully applied our probody technology to two different but complementary therapeutic strategies that we believe offer an appropriate balance of risk. Firstly, we have advanced pro-body therapeutics directed against validated immuno-oncology targets, such as CTLA-4 and PD-L1, with the goal of developing best-in-class assets and expanding the reach of these foundational anti-cancer therapies. Secondly, and in contrast, we have challenged ourselves to drug the undruggable and, in doing so, create potentially first-in-class cancer therapies for which we all agree there remains enormous unmet medical need. This strategy has led us to exciting programs evaluating CX2009 and CX2029, antibody drug conjugates against novel tumor antigens, CD166 and CD71, respectively. Moreover, our two therapeutic strategies dovetail into novel combination approaches, such as our ongoing phase two study combining CX2009 with CX072, our proprietary anti-PD-L1 inhibitor in triple negative breast cancer. thus illustrating the potential of our platform to unlock novel and potentially powerful combination strategies. I'll now briefly summarize our pro-body therapeutic pipeline before handing over to Amy for some additional detail. CX2009 is a wholly owned conditional antibody drug conjugate targeting CD166, currently in a three-arm phase two study in HER2 non-amplified breast cancer, which we initiated in the fourth quarter of 2020. Given that breast cancer remains the second leading cause of cancer deaths in women, and about 80% of breast cancer is HER2 non-amplified, we believe the opportunity for CX2009 is significant. The target of CX2009, CD166, is a glycoprotein that, among other functions, plays an important role in the formation and maintenance of tissue architecture. While its biological roles are not fully understood, CD166 is an attractive target to us since it's expressed at high levels in many types of tumors, including breast cancer. However, CD166 is also broadly expressed in normal tissues, thereby compromising its potential role as a conventional ADC target. CX2009 has demonstrated single-agent clinical activity in several cancer types, including breast, ovarian, lung, and head and neck cancers. We anticipate the initial data from our ongoing Phase II breast cancer study towards the end of this year. Turning to CX2029, a conditional antibody drug conjugate that targets CD71, which is also now in phase two. CD71 is a transmembrane glycoprotein receptor ubiquitously expressed in most normal tissues that functions in cellular iron uptake through its interaction with transferrin. CD71 is overexpressed on many cancers to allow tumor cells to meet their increased iron requirement for growth. While the high expression on malignant cells and its ability to be readily internalized makes CD71 an intensively studied target for the delivery of drugs into malignant cells, it's remained an elusive and undruggable target to date due to its broad expression on normal cells. Using our ProBody platform, we believe we have created a therapeutic window for CD71. And in partnership with App-V, we are now exploring this asset in phase two expansions in four different tumor types, with initial data anticipated in the fourth quarter of this year. In addition to our progress with CX2009 and CX2029, we're also very pleased to report that our partner, Bristol Myers Squibb, continues enrollment in its ongoing randomized phase 1-2a study of the anti-CTLA-4 probody, BMS986249, in patients with previously untreated, unresectable stage 3-4 melanoma. And BMS has expanded the scope of the Part 2b evaluation to include three new cohorts. These new cohorts are enrolling patients with advanced hepatocellular carcinoma, castration-resistant prostate cancer, and triple negative breast cancer. BMS also continues enrollment into a phase one study of a second anti-CTLA-4 pro body, BMS 986288. In addition to this continued clinical progress in our alliance with BMS, we look forward to continuing collaborative discovery and development activities towards generation of additional pro-body therapeutics in oncology. Turning now to our preclinical pipeline, where we continue to explore and leverage our platform, and specifically to our third investigational antibody drug conjugate, CX2043, which targets EPCAM, also known as CROPE1. EPCAM has been regarded as a high potential oncology target for decades, but efforts to generate systemic anti-EPCAM therapeutics have to date not been successful. However, locally derived approaches have shown some success, and in fact, a recombinant fusion protein that targets EPCAM has recently been submitted to the FDA for approval in bladder cancer, but this agent has to be instilled directly into the bladder. This is because EPCAM, or epithelial cell adhesion molecule, as the name suggests, is present on the majority of normal epithelial tissues, and conventional anti-EPCAM biologics administered systemically have significant dose-limiting toxicities. In contrast, our anti-EPCAM conditional ADC, CX2043, designed to be delivered systemically, has shown in pre-physical studies potent anti-tumor activity across multiple cancer types and superior tolerability in animal models compared to the corresponding unmasked conventional ADC. CX2043 is currently in IND-enabling studies, and an IND application is anticipated for late 2021. Another preclinical candidate, which we continue to advance towards the clinic, is CX904, our T cell engaging bispecific probody that we're developing in partnership with Amgen. CX904 targets the CD3 receptor on T cells and the epidermal growth factor receptor, or EGFR, on tumor cells. Now, although both EGFR and CD3 are validated in their own rights, we see this combination as undruggable for conventional bispecific approaches due to the extraordinary potency of both mechanisms when combined. In collaboration with Amgen, we continue our work towards unlocking potential in this target combination with our ProBody platform with the goal of ID filing this year. Staying with the bispecific theme, we're also excited about our recently initiated drug discovery activities under our collaboration with Astellas, also aimed at broadening the therapeutic window of bispecific T-cell engagers. Now I'd like to hand the call over to Amy for a deeper dive into our lead programs and where we're taking them. Amy.