CytomX Therapeutics, Inc.

Good afternoon, ladies and gentlemen. Thank you for standing by. Welcome to the Citomix Therapeutics First Quarter 2021 Financial Results Call. Please be advised that the day's call is being recorded. I would now like to hand the conference over to your host for today, Cao Cheng, Citomix 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, and Carlos Kempoy, Chief Financial Officer. Earlier today, we issued a press release that includes a summary of our first 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 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 the uncertainties surrounding the COVID-19 pandemic 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, 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'd like to turn the call now over to Shaun.

Thank you, Chao, and good afternoon, everyone. Thanks for joining us today for brief remarks on our progress during the first quarter of 2021. Q1 was marked by focused execution by the Cytomics team as we continue to drive towards initial data readouts from ongoing Phase II studies of our lead programs, the conditionally activated antibody drug conjugates Pralizatamab-Ravtanzine, formerly CX2009, and CX2029. I hope all of you had the opportunity to attend last month's investor event that we hosted, during which we took a deep dive into the science behind our pro-body therapeutic platform and also the phase two clinical strategies for our two lead assets. We were delighted to be joined at the event by key opinion leaders, Drs. Sarah Talani, Melissa Johnson, and John Lambert. An archived webcast is available on the events and presentations section of our website and I encourage everyone to review the presentations to learn more about our lead programs and our leadership in the field of conditional activation of biologic therapeutics. I'd like to start today with our program evaluating pralazetamab in patients with breast cancer. As a reminder, the phase two study is enrolling patients with HER2 non-amplified breast cancer into three parallel arms. Arm A is evaluating monotherapy in patients with hormone receptor-positive breast cancer. Arm B is evaluating monotherapy in patients with CD166-positive triple-negative breast cancer. Arm C is evaluating pronisatomab in combination with pacmelimab, our proprietary PD-L1 probody, and this is in patients with both CD166-positive and PD-L1-positive triple-negative breast cancer. Our first patients were treated in this study during Q1, and we continue to work towards initial data from ARMs A and B by the end of this year, and we anticipate initial data from ARMs C in 2022. Now, a notable development during Q1 relating to our pralazetamab breast cancer program was the full approval by FDA of sasituzumab govatican in the second and third line metastatic TNBC settings. based on data from the ASCENT phase three trial, and this is obviously a terrific development for patients. I want to emphasize here that CD166, the target of pranacetamab, is a novel target in breast cancer, and that our drug candidate utilizes a different payload to sasituzumab. Furthermore, in our phase one evaluation that we've reported previously, we saw meaningful clinical activity in a TMBC patient in the post-sasituzumab setting, where we expect high unmet medical need to remain. Indeed, the anticipated unmet need in the post-sacituzumab setting is underscored by the 5% response rate in patients randomized to the control chemotherapy arm in the ASCENT study and their median progression-free survival of 1.7 months and median overall survival barely exceeding 6 months. Accordingly, our development strategy in TMBC will continue to assess pathways to accelerated and full approval for prazatomab a novel and potentially first-in-class treatment for this disease. I'd like to now move on to CX2029, our conditionally activated ADC targeting CD71, the transferrin receptor. Patient enrollment continued during Q1 in the Phase II expansion study, evaluating CX2029 as a single agent in four cohorts, squamous non-small cell lung cancer, head and neck squamous cell carcinoma, esophageal and gastroesophageal junction cancers, and diffuse large B-cell lymphoma. As with pralazatamab, we continue to work towards initial data for CX2029 in the fourth quarter of this year, most likely from the squamous lung and head and neck cohorts, with initial data from the additional cohorts anticipated in 2022. Turning now to our research and preclinical pipeline, Another key development for cytomics in Q1 was the first presentation of our emerging work in the field of conditionally activated cytokines. One of the defining advantages of our ProBody platform that we discussed during our recent investor event is its versatility and tunability. And this has allowed us to continuously innovate across multiple biologic modalities. Our interest in cytokines stems from the fact that systemic toxicity and poor exposure have limited the clinical success of this important and highly potent class of immune modulators. Industry interest in this area is understandably high at the moment, given the landmark progress made in recent years on interleukin-2, a prototypical immune modulator currently the focus of many efforts to improve its therapeutic window. Enormous room exists to optimize cytokines for cancer therapy, and cytomics aims to be at the forefront. By leveraging the depth of our expertise in protein engineering, protease biology, and our understanding of the tumor microenvironment, we have now demonstrated our ability to be a meaningful player in this field. Leading our cytokine program is a protease-activatable version of interferon-alpha-2b, to which we have directed our sophisticated protein engineering approaches to improve therapeutic window and unlock potential in this powerful immunotherapy. We'll have more to say in the future as we advance this exciting new frontier of cytokines at Cytomix. Another area of intense industry interest at present is bispecific T cell engagers. We continue to work closely with our partner Amgen on IND enabling studies for CX904, our conditionally activated T cell bispecific antibody targeting EGFR and CD3. IND submission for CX904 is planned for late 2021. Additionally, progress continued to be made in Q1 with drug discovery activities for this modality in our strategic collaboration with our newest partner, Astellas. During Q1, we also continued to advance CX2043, our conditionally activated antibody drug conjugate directed against the abundant tumor antigen, EPCAM. IND-enabling studies continue to progress, although here we have experienced some delays as a result of recent supply chain interruptions And based on a reassessment of the program timeline, we no longer expect to submit an IND in 2021, and we're currently reassessing the timeline for this program. Returning to the clinical pipeline, our partner Bristol-Myers Squibb continued to make progress, enrolling in the Part 2b evaluation of BMS 986249, a pro-body version of ipilimumab, in combination with nivolumab in a randomized study in patients with metastatic melanoma. BMS also recently initiated three new cohorts testing this combination in patients with advanced hepatocellular carcinoma, metastatic castration-resistant prostate cancer, and advanced TMBC. With these updates, I would like to turn the call over to Carlos to review our financials.