CytomX Therapeutics, Inc.

Good afternoon, ladies and gentlemen. Thank you for standing by. Welcome to the Citamix Therapeutics Second Quarter 2021 Financial Results Call. Please be advised that today's call is being recorded. I would now like to hand the conference over to your host today, Chao Cheng, Citamix Vice President, Investor Relations and Corporate Communications. Please go ahead.

Thank you, Suzanne. Good afternoon and thank you for joining us. With me today are Dr. Sean McCarthy, Cytomics' 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 second quarter 2021 financial results and highlights the important progress we made during the quarter. 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 the recording of this call can be found under the Investors and News section of our website at sitomix.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 the uncertainties surrounding the COVID-19 pandemic that are difficult to predict today. 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, including our Form 10Q 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, Chao, and good afternoon, everyone. Thanks for joining us today for an update on recent progress and developments within our clinical and preclinical programs and operations. At Cytomics, we continue to dedicate ourselves to working towards making a meaningful difference in cancer treatment by being different and thinking differently. We have pioneered an entirely new way to design therapeutic antibodies and other biologic modalities, and we have used our technology to purposefully go after high-potential targets that were previously considered undruggable in order to stand out from the crowd and build long-term value. We're exploiting an Achilles heel of tumor biology to combat cancer in new and unique ways. Our technology, the ProBody platform, is a conditional activation strategy that uses protease-dependent peptide masking. Given that proteases are activated in the tumor microenvironment but tightly controlled in normal tissues, our strategy is designed to reduce antibody binding in normal tissues while maximizing target binding in cancer. During the second quarter, we continue to advance our broad pipeline of probody therapeutics across multiple modalities and cancer types, including our two conditionally activated antibody drug conjugates, or ADCs, Pralizatamab-Raptanzine, also known as CX2009, and CX2029, both of which are currently in phase two clinical investigations encompassing multiple tumor types. Let me begin with CX2029, our CD71-directed conditionally-activated ADC, for which we recently published results from a Phase I first-in-human study in patients with advanced solid tumors. This important work by Cytomix, in collaboration with our partner, AbbVie, has demonstrated for the first time that CD71 can be successfully targeted with a drug-conjugated antibody using our technology. Why CD71? Well, CD71, or the transferrin receptor, has been a very attractive but elusive oncology target for ADC development. It's highly expressed on the vast majority of tumors, since all growing and dividing cells need iron for many metabolic processes. And CD71 is an extremely efficient transport system, fully internalizing antibodies within minutes of binding. However, CD71 was previously deemed undruggable with conventional ADCs, because it's also highly expressed in and vital to normal tissue growth and development. As we have now published in clinical cancer research, in phase one dose escalation, CX2029 was generally well tolerated and produced encouraging anti-cancer activity, notably in patients with squamous non-small cell lung and head and neck cancers, a first for an ADC against this high potential target. These two cancer types are now part of an ongoing four-cohort phase two expansion study. We dosed the first patients in the expansion phase in November 2020, and Amy will give you an update in a few moments on where things stand. Moving on to Pralizatamab-Raptantin, our wholly-owned, first-in-class, conditionally-activated ADC directed toward another novel oncology target, CD166. CD166, also known as activated leukocyte cell adhesion molecule, or ALCAM, is a transmembrane glycoprotein that has been reported to play a role in multiple aspects of tumor biology, including angiogenesis and invasiveness. CD166 is highly expressed on the cell surface of many cancer types and, as such, has attractive molecular properties as an ADC target. However, developing a conventional ADC against CD166 is precluded by its widespread presence on healthy tissues. Our pioneering Phase I clinical work on CD166 has shown that Pralicetamab can achieve clinically meaningful outcomes in patients with different cancer types, including, but not limited to, HER2 non-amplified breast cancer. These results support our current three-arm Phase II study in breast cancer, and we're excited about the potential for this asset in this indication, and more broadly in other CD166-expressing cancers where substantial unmet need remains. Amy will also provide you with more details of the design and status of the Pranidazumab Phase 2 study shortly. Turning now briefly to our work in immuno-oncology and our partner clinical programs with Bristol-Myers Squibb, aimed at broadening the therapeutic window and therefore the clinical utility of anti-CTLA-4 immunotherapy. BMS-986249 and BMS-986288, discovered using the Cytomics platform, are probody versions of different forms of the anti-CTLA-4 therapeutic antibody, ipilimumab. BMS 986249, having successfully completed dose escalation, is currently being evaluated in a randomized phase 2 study in combination with the anti-PD-1 antibody nivolumab in patients with metastatic melanoma. Importantly, the control arm in this study is nevo plus ipilimumab rather than nevomonotherapy, representing the current standard of care based on five-year follow-up from Checkmate 067, which showed a significant increase in overall survival with this combination in melanoma over NEVO monotherapy. BMS 986249 is also being studied in combination with NEVO in three additional advanced settings, hepatocellular carcinoma, castration-resistant prostate cancer, and triple negative breast cancer. BMS 986288, a pro-body version of a non-fucosylated ipilimumab with increased Treg depletion properties, continues to be evaluated in a Phase I study in advanced solid cancers as monotherapy and in combination with NEVA. Switching now to our research and preclinical programs in the field of conditionally activated T-cell bispecific antibodies, we see a major opportunity here to improve the therapeutic window of this modality using our platform, and we're pursuing multiple projects with our partners, Amgen had dispelled. CX904 is a conditionally activated T cell engaging bispecific directed against EGFR on tumor cells and CD3 on T cells, and this is in IND enabling studies. We recently submitted a pre-IND meeting request to the FDA, and we expect written responses to our questions from the regulatory agency in the third quarter of this year. We will continue to discuss the program with our partner, Amgen, and we're working towards the filing of an IND for CX904 in late 2021. Q2 was also highly productive for cytomics in terms of publication of our work in peer-reviewed journals. A total of five manuscripts were recently published covering our work that ranges from phase one investigation of CX2029, as I already mentioned, to multiple publications describing our clinical work with pacmelamab or CX072, our wholly owned conditionally activated antibody against PD-L1. Of particular note, our recent collaborative work with Dr. Elizabeth DeVries of the University Medical Center, Groningen, in the Netherlands, has investigated the biodistribution of pacnilamab in cancer patients using clinical imaging. This study has shed important light on the molecular performance of the probody platform in cancer patients, including the direct demonstration of activation and binding of pacnilamab to primary and metastatic tumors. Another recent publication of particular note is our landmark preclinical study of a probody immuno-oncology agonist in the proceedings of the National Academy of Sciences. As you will recall, we introduced earlier this year our advancement of our conditional activation technology into the cytokine space. This recent PNAS paper takes things even further as the first published application of the Cytomix platform to agonist antibodies in immuno-oncology, emphasizing the versatility of our platform. Specifically, together with our collaborators, we have shown in this publication that an anti-CD137 probody retains post-attach tumor activity with significantly reduced liver toxicity compared to an unmasked antibody when assessed in the same mass model system. This is exactly what our platform is designed to do. The paper also includes extensive characterization of pro-body activation by tumors. Taken together, these publications underscore the immense progress we've made across our pipeline and platform with our first generations of pro-body therapeutics. field that Cytomix has defined and continues to lead, and we continue to innovate on the core platform and across many therapeutic modalities. Let me now hand the call over to Amy for additional detail and updates on our lead clinical programs.