Good afternoon, ladies and gentlemen. Thank you for standing by and welcome to CytomX Therapeutics Third Quarter 2021 Financial Results Call. Please be advised that today's call is being recorded. I'll now hand the call over to your host for today, Chau Cheng, CytomX's Vice President of Investor Relations and Corporate Communications. Sir, please go ahead.

Thank you, Jessie. Good afternoon and thank you for joining us. With me today are Dr. Sean McCarthy, CytomX's President, Chief Executive Officer and Chairman; and Carlos Campoy, Chief Financial Officer. Earlier today we issued a press release that includes the summary of our third quarter 2021 financial results and highlight the important progress we've 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 a recording of this call can be found under the Investors and News section of our website at cytomx.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 10-Q 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 Sean.

Thank you, Chau, and good afternoon, everyone. Thanks for joining us today for an update on recent progress and developments with our clinical and preclinical programs and our company operations. At CytomX, we are dedicated to destroying cancer differently. Leveraging our Probody technology platform, we have created a robust and differentiated pipeline of novel potential first-in-class and best-in-class conditionally activated biologics. Conditionally activated biologics offer much promise for the treatment of cancer and CytomX's ambition is to discover, develop and commercialize more effective and safer therapies. The lead programs in our broad development pipeline are the conditionally activated antibody-drug conjugates CX-2009 praluzatamab ravtansine, directed toward CD166 and CX-2029, directed toward CD71, the transparent receptor. These two potentially first-in-class assets both target novel tumor antigens and are currently being evaluated in Phase 2 studies. Praluzatamab is under evaluation in a three-arm Phase 2 study focused on HER2-nonamplified breast cancer with initial data readouts anticipated in 2022. Arm A of this study is focused on hormone receptor positive disease. Arm B is focused on triple-negative breast cancer and Arm C is focused on triple-negative breast cancer in combination with our proprietary PD-L1 inhibitor pacmilimab. All three arms of this study are open and enrolling and enrollments accelerated in Q3 with more than 30 sites actively recruiting patients including additional study centers in Spain and South Korea. Moving now to CX-2029 targeting CD71, which is being studied in four expansion cohorts, building on our previously reported Phase 1 dose escalation study where we observe promising clinical signals in squamous, non-small cell lung cancer and squamous head and neck cancer. Our ongoing study is the expansion phase of a Phase 1/2 study, evaluating CX-2029 in these two indications and also in esophageal gastroesophageal junction cancers and diffused large B-cell lymphoma. Each cohort aims to…

Thank you, Sean. CytomX remains in a strong financial position to support our bold clinical and research agenda that Sean just reviewed, which is to maximize the benefit of our conditionally activated therapeutic candidates for people with cancer. As of September 30, 2021, we had $336 million in cash, cash equivalents and investments which we project will fund the operations of the company well into 2023. For the third quarter 2021, revenue was $80 million, relatively flat when compared to the corresponding period in 2020. R&D expenses increased $5 million to $29 million during the three months ended September 30, 2021 compared to the third quarter of 2020. The increase was driven by personnel, clinical trial and consulting and contract expenses primarily related to praluzatamab and CX-2029. G&A expenses were $11 million during the three-month ended September 30, 2021, an increase of $2.5 million compared to the same period in 2020. The increase was attributable to personnel-related expenses as well as professional services. With that, I'll turn the call back to Sean.

Thanks, Carlos. I want to close by emphasizing the leadership position that CytomX has established in the field of conditionally activated biologics. Across multiple targets and within our broad and deep therapeutic pipeline, we have clearly demonstrated that conditional masking is a versatile approach to enhancing R&D creating a therapeutic window for high potential cancer treatments and we see enormous potential in our technology. At CytomX, we continue to innovate by advancing a novel therapeutic programs toward the clinic including CX-904 and our emerging work in the field of conditional cytokines. Our partner, BMS, continues to work toward data from a randomized Phase 2 study comparing our ipilimumab Probody in combination with nivolumab [indiscernible] front-line metastatic melanoma study. I want to thank our clinical whose intense focus has allowed us to make excellent progress toward Phase 2 readouts for our first-in-class lead clinical programs that really are pushing the boundaries of ADC drug development by leveraging previously un-druggable targets. As we continue to drive the translational science of the Probody platform and the tumor microenvironment, we are honored privileged to have Dr. Alan Ashworth join CytomX's Board of Directors. As President of the UCSF Helen Diller Family Comprehensive Cancer Center and former Chief Executive of the Institute of Cancer Research in the UK, Alan is a world-renowned expert in cancer research and an accomplished global leader in cancer therapy development. We look forward to Alan's contributions as we advance our clinical pipeline toward key Phase 2 inflection points, and as we continue to lead the field of conditionally activated therapeutics. With that, Operator, please open the call up for Q&A.

Thank you, speakers. [Operator Instructions] Speakers, our first question is from the line of Mara Goldstein of Mizuho. Your line is now open.

Hi. This is Praful for Mara Goldstein. My question is on CX-2029. First of all, you mentioned there will be data in December. Have you already identified venues [indiscernible] for that? And secondarily, to what extent do you think this data set would give clarity on how the toxicity of this compound can be managed? Thank you.

Yes, hi. Thanks for the question. First of all -- or questions, I would say -- first of all, with regards to the venue. Yes. We're working toward announcing data next month and that will be via press release and associated conference call. In terms of what to expect, I'll comment on the safety side, also, maybe a little more broadly. This will be initial data, this will be a first look at a meaningful number of patients treated at the RP2D of 3 mg/kg, Q3 week. The goal in each of the cohorts of the expansion phase is to enroll 25 efficacy evaluable patients and we expect for these first two cohorts to be able to present meaningful progress toward that goal. It will include likely a mix of patients with one or more post-baseline scans and of course the follow-up of patients with regard to the incidents in management of anemia, which is the side effects that we're obviously tracking most closely, given what we learned in Phase 1.

Good. Thanks.

Next question is from Anupam Rama of JP Morgan. Your line is now open.

Thanks so much for taking the question. Just two quick ones from me. First one, 2009, you guys noted the site expansion, is there any plans to further expand your sites and what type of enrollment sort of progress and trajectory might you need to give us a little bit more granular time lines for data than broadly 2022? That's the first question. The second one is follow-on to the first one, which is, I guess, thinking about 2029, what would get you excited as kind of a win scenario? Thanks so much.

Yes, Anupam, thanks for the questions. Regarding 2009, we're very pleased with the progress in Q3 with site activation and ongoing enrollment. We're not ready to give additional specifics of enrollment numbers, but we are pleased with the progress that the team has made over the last few months. We will be adding additional sites in the coming months as well. But for now, our guidance continues to be data in 2022. We'll be working to refine that as we move into the new year. Regarding to 2029 in the two expansion cohorts that we're planning to present updates on next month in head and neck and lung, obviously we're in the second, third line setting here and significant unmet need. You heard our comments on the nature of the unmet need in these patient populations and we're thinking, broadly speaking, impact on these diseases with durations of response of four to six months would be terrific response rates in the 20 plus percent range would be great, given that these patients have few options and also given that this is a novel drug candidate against a very unique target. That intrinsically makes it a first-in-class therapeutic. So we'll see what we get, but that's broadly how we're thinking.

Thanks so much for taking our questions.

My pleasure.

Next question is from Roger Song of Jefferies. Your line is now open.

Great. Thank you for taking my question. The first question also related to 2029. I think, Sean, you already mentioned the bar of to what data you were seeing there will be a weak scenario, which is kind of resonate, I think as well. And then maybe moving a step further is, this is like a monotherapy setting and if given the tox safety profile you have been seeing and the potential efficacy in this setting for those patients, what kind of combination therapy you potentially will be considering?

Yes. Hi, Roger. Thanks. Great question. So, you're right to point out that of course right now, we're laser-focused on characterizing the monotherapy activity of 2029 and it's not lost on us, of course, but this is an agent that could very well be combined with a range of different agents in the future. There's nothing really that we see in the anemia side effect that would preclude the types of combinations that one might think of pursuing. So we don't see that as a particular barrier. I don't want to comment on specific combinations. I'm sure you can think about what they might be, but we do know that [indiscernible] with a range of different mechanisms and we'll be interested to explore those in the future. I wanted to just also restate coming back to the question previously regarding what success looks like. I wanted to just restate what we saw in Phase 1 dose escalation with these two indications and starting with lung where with squamous lung and Phase 1 dose escalation, we had four patients enrolled. One of those patients was treated at 1 mg/kg, which we didn't think would be an efficacious dose based on all of the modeling that we had done in the three that received 2 mg/kg or above. We saw two confirmed PRs in one stable disease. So yes, certainly promising and that's the basis that led to the expansion that we're running right now in these additional 25 patients. In head and neck, we had eight patients enrolled in squamous head and neck, eight patients enrolled in Phase 1 dose escalation treated at 2 mg/kg or above. We saw six patients and we have seven efficacy evaluable. We saw six with stable disease and one with a very deep and extended PR that actually lasted for more than six months. That's the basis of course on which we now are running these expansions and that we'll see what we see when we review and present the data next month.

That's great. Really appreciate all the color. Maybe my another question is related to that 904. We understand the EGFR is definitely some kind of a [high mandate]. Just curious, any kind of additional thoughts around the plan and the tumor types that the timing for the cleaning call initiation and potential data?

Not much more to say there at this point in time. We are pleased with the progress we're making toward IND filing and on our last call, we did mention that we were working toward a pre-IND interaction with FDA and we had that interaction during Q3. It was highly productive and helpful in helping us continue to shape the IND filing and the Phase 1 strategy. We're obviously looking forward to getting that IND filed and getting going in the clinic in 2022.

Okay, that's great. Thank you. That's all from me.

[Operator Instructions] Next question is from Joe Catanzaro of Piper Sandler. Your line is now open.

Hey, guys. Thanks so much for taking my question. Maybe just another one on CX-2029 here, but I think more so about tolerability in the bar there and how we should think about what's the appropriate or reasonable rates of high-grade anemia transfusion burden growth factor support. Or should we be thinking more if the [indiscernible] meets the hurdles you just sort of said, then that in itself is indicative of a good tolerability profile. Thanks.

Yes. Hi, Joe. Great question. Yes, so let me just talk a bit more broadly about anemia, how we're thinking about it based on the Phase 1 work. But first thing to say that and we said this many times before, that with this drug candidate, the anemia is predictable, reversible and we believe manageable with several interventions including transfusions, those delays, those reductions and we continue to explore the opportunities for erythrocyte stimulating growth factors like darbepoetin, given that this appears to be an effect on early hematopoiesis. It's important to note that there were no events of anemia that led to discontinuation of CX-2029 in the Phase 1 study. That's important. We're obviously going to learn a lot more from the expansions, but that's the big picture on anemia. You're right to point out though, I would agree with you, that it is an important consideration to consider the anemia in the context of the overall profile of the drug as we gain more insight into this single-agent activity.

Okay, great. Thanks for taking my question.

My pleasure.

Thank you, participants. At this time, I'll now hand the call back over to Chau Cheng for his closing remarks.

On behalf of the executive team, I'd like to thank you all very much for joining us this afternoon. We look forward to updating you in the future on our ongoing progress.

Ladies and gentlemen this concludes today’s conference call. Thank you all for participating. You may now disconnect and have a great day.