Good afternoon everyone. Thank you for standing by. Welcome to the CytomX Therapeutics Fourth Quarter and Full Year 2021 Financial Results Call. Please be advised that today's call is being recorded. I would now like to hand the call over to your host today, Chau Cheng, CytomX's Vice President, Investor Relations and Corporate Communications. Please go ahead.

Thank you, Michelle. Good afternoon and thank you for joining us. With me today are Dr. Sean McCarthy, CytomX' Chief Executive Officer and Chairman; Dr. Amy Peterson, President and Chief Operating Officer; and Chris Ogden, Vice President, Finance and Accounting. Earlier today, we issued a press release that includes a summary of our fourth quarter and full year 2021 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 recording of this call can be found under the Investors and News section of our website at cytomx.com. Please note that 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 uncertainty surrounding the COVID 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-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'd like to turn the call now over to Sean.

Thanks, Chau and good afternoon, everyone. Thanks for joining us today for an update on recent progress at CytomX. Before I begin, I'd like to note that on February 14, we issued an 8-K announcing that our Chief Financial Officer, Carlos Campoy, has begun a temporary personal leave of absence. We very much look forward to Carlos return. In the interim, our Vice President of Finance, Chris Ogden, who joins us on the call today, has assumed the role of Principal Accounting Officer and will oversee day-to-day operations of our finance functions. I would also like to congratulate Amy on her recent promotion to President and Chief Operating Officer of CytomX, an expanded role in which she will have responsibility for all aspects of product development as we advance towards potential registrational studies and beyond. I would like to start today's call by taking a step back to comment on our overarching corporate strategy as to reflect on our many accomplishments over the past year, resulting from sustained and relentless execution by the CytomX team. I'll then hand the call over to Amy to provide updates on broad and increasingly mature therapeutic pipeline. CytomX is a clinical stage oncology-focused biopharmaceutical company dedicated to destroying cancer differently. We are utilizing our industry-leading proprietary Probody platform to create biologic therapeutics to make the biggest possible difference we can to the lives of people with cancer. Our ambition is to build a long-term multiproduct commercial biopharmaceutical company. Our innovative platform is designed to enable conditional activation of therapeutic candidates within the tumor microenvironment, minimizing drug activity in healthy tissues, resulting in more selective targeting of tumor tissue. We have established conditional activation as a strategic area of current biologics research and development in the industry. We believe our innovative approach has the potential…

Thank you, Sean. I am very excited about the progress we are making at CytomX and look forward to continuing to deliver on our goal of building our company for the long term and making real our promise to positively impact the lives of people with cancer. In 2021, we made significant advancements despite contending with the COVID-19 pandemic. Let me begin with praluzatamab ravtansine, our wholly owned Phase II asset. As Sean mentioned, praluzatamab is a CD166 directed conditionally activated ADC with first-in-class potential in breast cancer and we recently published full data from our Phase I monotherapy dose escalation study in clinical cancer research. In this paper, we reported encouraging anticancer activity in patients with either triple negative or hormone receptor positive, HER2 non-amplified breast cancer. In particular, the clinical benefit rate, defined as any partial or complete response or stable disease at 16 or 24 weeks was 41% and 28%, respectively and despite a median of seven prior therapies. The treatment landscape in breast cancer continues to evolve, especially in the area of ADCs with the recent results from the DESTINY-Breast03 study evaluating trastuzumab deruxtecan in patients with HER2 low breast cancer and, of course, the anticipated Phase III results from sacituzumab in patients with hormone receptor-positive breast cancer. ADCs are clearly making an impact in breast cancer and we are excited about the potential for praluzatamab. Let me discuss the design of our ongoing Phase II study in a bit more detail. The tolerability and activity of praluzatamab monotherapy is being assessed in arms A and B in approximately 40 efficacy evaluable patients with either hormone receptor-positive disease or triple-negative disease, respectively. Our enrollment criteria in all arms exclude patients with HER2 amplified breast cancer meaning we are enrolling patients with either HER2-low or HER2 [indiscernible]…

Thank you, Amy. CytomX entered 2022 with a strong balance sheet. As of December 31, 2021, as Sean mentioned earlier, we had $305 million in cash, cash equivalents and investments which we project will fund the operations of the company well into 2023. For the fourth quarter of 2021, revenue was $20 million compared to $6 million [ph] for the corresponding period in 2020. The increase was largely related to the CD71 collaboration with AbbVie. R&D expenses increased $15 million to $37 million during the three months ended December 31, 2021, compared to the corresponding period in 2020. The increase was driven by personnel expenses, clinical trial activities and consulting and contract services to support our preclinical and clinical portfolio. G&A expenses were $9.5 million during the three months ended December 31, 2021, an increase of $300,000 compared to the same period in 2020 due mainly to increased personnel-related expenses. Before I hand the call back to Sean for his closing remarks, I want to reiterate Sean's point earlier on prudent financial management at CytomX. As we advance our pipeline to key inflection points, we will remain judicious with our capital and continue to marshal our cash resources thoughtfully. Sean?

Thanks, Chris and Amy. To wrap up, CytomX had a very strong 2021 and we have entered 2022 intensely focused on continued pipeline execution. Across multiple targets and within our broad and deep therapeutic pipeline, we have clearly demonstrated that conditional activation is a versatile approach to enhancing or indeed creating a therapeutic window for high-potential cancer treatments and we see enormous opportunity for our technology. We have much more work to do to destroy cancer and our different approach, leveraging our industry-leading Probody platform offers unique opportunities to make a real impact. As our pipeline continues to grow and mature, we are working in increasingly defined areas of unmet medical need as evidenced by the encouraging clinical activity of CX-2029 in lung cancer and our ongoing Phase II studies of praluzatamab in breast cancer and of our anti-CTLA-4 Probody in melanoma. The substantial investments we have made in recent years in our platform and in our pipeline position us well to build long-term value as we drive towards key milestones in 2022 and for our most advanced programs, whilst also advancing many new product candidates towards the clinic. I want to extend my sincere thanks to the CytomX team for their ongoing dedication and commitment to our vision and mission. And in closing, our thoughts are with everyone impacted by the unfolding events in Ukraine and we hope for a peaceful solution to the crisis. With that, operator, we can now open the call up for Q&A.

[Operator Instructions] And our first question comes from the line of Gavin Scott with JPMorgan. Your line is open. Please go ahead.

Hi, thanks for the update and thanks for taking our questions. Question on CX-2009 and Arm B in the TNBC breast cancer population. I'm just curious on the opportunity in the CD166 positive TNBC. And is there any stratification criteria in the protocol to see, I guess, prespecified analysis across CD166 expression levels?

Yes. Gavin, thanks for the question. Let me kick that one off. So as Amy mentioned a few moments ago, across Arms A and B with Arm A, what we observed in Phase and in the public databases is high expression of CD166 in the majority of patients. So in Arm A, we're not selecting for target selection is not a criteria for enrollment. In contrast to Arm B where in our Phase I experience and also looking in the data -- the public databases, you can see that CD166 is more heterogeneous. And so we are utilizing a patient selection strategy for Arm B. We do require in both Arms A and B, CD166 high for the definition of efficacy evaluable. That's something that we're not discussing in a lot of detail right now in terms of where that cutoff is going to be. We need to learn more about the target in triple negative in particular. And given, as you know, that it's a diagnosis of exclusion with fairly heterogeneous histological definition. So more to come on that as we go through the year.

Great. Thank you.

Thank you. And our next question comes from the line of Kaveri Pohlman with BTIG. Your line is open. Please go ahead.

Yes, good afternoon. And thanks for the update. For TNBC Study again, are you enrolling patients who are [indiscernible] experience and will we see any data for that?

Yes, Kaveri, thanks for the question. So if I could just repeat it. So are we enrolling patients who are experienced on Trodelvy. And the short answer is, yes, we do expect to see some patients for sure, having experienced Trodelvy. I want to remind everyone that in our previously reported clinical study, we did see a very intriguing response in a patient who had progressed on Trodelvy on sacituzumab. So we have evidence that praluzatamab can work in that patient population. We are enrolling in the U.S. and ex U.S. And so we would expect, given the approval in the U.S. and the pending approvals ex U.S. that we would end up with a somewhat mixed patient population, some of whom have and some of whom have not been treated with Trodelvy.

Got it. That's useful. And regarding the EGFR CD3 bispecific, the triple meeting poster shows a two plus two design for this molecule. Can you talk about your rationale for using two plus two formats because I believe that format is mostly used for better safety but 904 is already masked to provide tumor-directed activity.

Yes. Good question and thanks for pointing out some of our previously published work on the program. So -- and just to be clear, the two plus two you're referring to is the dual antigen for both CD3, CD3 and two EGFRs, I believe, correct?

Correct.

Yes. So we haven't disclosed the actual molecular anatomy of 904 to this point. We have done a considerable amount of additional optimization of that program to ultimately reach 904 as the clinical candidate, in collaboration with our partner, Amgen. And so actually, the structure of 904 is not yet disclosed.

Got it. Thank you. And thanks for taking my questions.

You're welcome.

Thank you. And our next question comes from the line of Joe Catanzaro with Piper Stanley. Your line is open. Please go ahead.

Hey, thanks for taking my question. Maybe the first one for me. I think for CX-2029 initial Phase II readout. Ahead of that, you characterize the size of the data set that's going to show meaningful progress towards the planned patients per cohort in that study. So maybe with that, at this point, I guess, how would you characterize expectations for sample size for 2009's initial Phase II monotherapy readouts? And I have a follow-up.

Joe, thanks for the question. So just to recap the goals of the Phase II, the 3-arm study. The goal is to enroll 40, 4-0, efficacy evaluable patients in each arm. And we are making very good progress with enrollment. As you may recall, we had a few bumps in the road last year but the team has done an amazing job. And we are making progress. Our guidance at this point is from data from Arms A and B initial data this year. We do expect it to be meaningful numbers of patients. We're not quite ready to comment on a specific number at this point.

Okay, got it. And then, if I could just ask a follow-up. I was scanning through the 2009 publication and I noticed the figure that showed a strong correlation between unmasked antibody and the tumor and expression of CD166. And I'm trying to understand what the cause-effect relationship there is if you could help with that, that would be great.

Yes, it's a great question and thanks for studying the publication in detail. There's a lot in there that we wanted to report. I don't want to get to too many details here but I mean there's a lot still to learn about the sequence of events with regard to Probody functionality. And one can imagine this derives from a relationship between activation and target level and the order in which the Probody actually becomes converted into the active form. So it's an intriguing observation, there's a little bit written in the paper about that but we think it provides some interesting translational insight into how this platform functions.

Okay. Got it. Thanks for taking my questions.

You're welcome.

Thank you. And our next question comes from the line of Mara Goldstein with Mizuho. Your line is open. Please go ahead.

Hi, thank you for taking my questions. This is Supawat [ph] for Mara Goldstein. My question is on CX-2009 which -- so the data is now, now expecting the second half of 2022. Given that it was previously guided in 2022, is it fair to characterize that as a slight delay. And just wondering if you can provide a little bit color about that. Yes, that would be good.

Good question. I would not characterize it as a delay. I think that the -- it's obviously a refinement of our guidance which we wanted to give today. We are -- given this is a fairly substantial Phase II study, we are working towards giving meaningful updates. And so giving ourselves a little bit more time to get data that will provide us with pointers to the next steps in the product development and also be able to share that with external stakeholders, we think it's the right thing to do. So we don't want to -- we see no need to communicate data that is too premature.

Got it. Thank you.

Thank you. And our next question comes from the line of Roger Song with Jefferies. Your line is open. Please go ahead.

Great. Thank you for taking our questions. Just quickly to confirm some of the logistics for 2029, you are expecting the non-cell lung cancer update in second half, any comment around the other cohort like DJ and the DLBCL data readout. Similarly, for the four. Any color around the data timing will be helpful.

Roger, thanks for the questions. So yes, so regarding CX-2029 second half -- as you can see, we've got a significant amount of data that the team is working towards disclosing in the second half of this year. So it's going to be an important time for the pipeline for the company. We're not ready yet to say really anything else about the additional cohorts in 2029, enrollment continues, in esophageal and gastroesophageal junction. As you know, DLBCL is also included in that expansion phase. So we'll provide additional commentary as the year goes on. With regard to 904, just getting that up and running, team did a great job getting the IND cleared and would not expect any data from 904 this year. We need to get into dose escalation, get going. And as you know, with agents like this T cell engaging bispecifics, starting doses tend to be on the low side. So we're going to give ourselves some time there as well. So not ready to guide on data for 904 at this stage.

Got it. Thank you.

You're welcome.

Thank you. And our next question comes from the line of Mitchell Kapoor with H.C. Wainwright. Your line is open. Please go ahead.

Hey, there. Thanks for taking the questions. The first one, I just wanted to ask on Arm C of the Phase II of praluzatamab. What kind of added benefit could we expect from pacmilimab to show in TNBC? And how should we think about it being positive when we compare to separation from monotherapy?

Yes. Thanks for the question, Mitch. Let me hand that one over to Amy.

Mitch, thanks for the question. One thing that I want to state is we have demonstrated monotherapy activity with each of these agents in triple negative breast cancer. So we reported monotherapy activity with pacmilimab in the Phase I expansion in triple-negative breast cancer and not only triple-negative breast cancer but a very difficult subset of triple-negative breast cancer to treat which is inflammatory breast cancer. So we observed activity. We also observed activity in triple-negative breast cancer with 2009. When it comes to what you might see from the combination, that it's not yet clear what we need to see -- we know that checkpoint inhibition works in combination with chemotherapy, pembrolizumab being approved in maintaining it's approval in frontline triple-negative breast cancer. And so we know what we think it might need to look like but we aren't necessarily able to say anything more specific about what we're hoping to see. I think we think about response rates with sacituzumab as monotherapy in this setting in the mid-30s. We would want to see something that is compelling in a patient population that is possibly refractory to sacituzumab.

Great. And then just thinking about any potential milestones we could see this year could you talk about any of those that we could see from collaborators?

Yes. Thanks, Mitch, for the question. We're not -- we haven't disclosed any additional milestone structures in our alliances at this point. As I mentioned in my remarks -- early on in my comments today, our cash runway projection of well into 2023 does not take into account any milestones or any new BD activity. And we have -- as I said, consistently been able to finance the company through a mix of dilutive and nondilutive capital. I expect that to continue to be the case.

Great. Thank you very much.

You're welcome.

Thank you. And our next question comes from the line of Peter Lawson with Barclays. Your line is open. Please go ahead.

Thanks for taking the questions. Just as regards to the update, thanks for the timing around updates in the second half. Anything you can say around kind of the number of patients or time on therapy for the triple-negative and HR-positive HER2-negative arms.

Peter, this is Amy. Thanks for the question. So for Arm A which is hormone receptor positive breast cancer, one of the key secondary endpoints is going to be CBR24 which is a stable CBR stable disease through 24 weeks. And obviously, that takes six months to get if you're going to get to 24 weeks. So there's a time component to this. And response rates are not necessarily the strongest indicator of activity in this particular disease. We'll see what the details of the data are with deruxtecan. And of course, we're interested to see what happens with sacituzumab in this setting with regard to response rates. But we're really focusing on CBR24 and then of course, PFS because if you think about what might be the next study, it's going to be depending on what the data show us. And if they're hinting in a way that favors activity with this, it would be a randomized study where PFS might be the endpoint. So we'll be looking at those endpoints very carefully in Arm. For Arm B and there, we're talking about a patient population of approximately 40, 4-0 efficacy evaluable patients. So a population that we can look at that we can get our heads around and that we can begin to define the point estimates for the pivotal study. That's what we're talking about when we say a meaningful patient sample size. The same thing for triple-negative breast cancer. Here, of course, response rates can be the basis for accelerated approval. However, as you already know, we need durability of those responses. You can't just get the first confirmation and report the response rate. So response rate, durability of response are going to be the two key endpoints that we're focusing on in that patient population. And again, a meaningful patient population. And what do I mean by meaningful? Something where if we look at it, we would know how to take this molecule into the next study with the next study having an eye towards registration.

Got you. Same question really for 2029 in non-small cell lung cancer, kind of how much of an update we're going to get? Is that kind of durability plus additional patients?

So I think, yes, the same principles apply here, Peter. Of course, the population is slightly smaller. It's 25% efficacy evaluable. But again, it's efficacy of valuable patients who had at least one post-baseline assessment. And there, again, we're looking at response rates and durability of the response. PFS, those are all the things that will help inform whether this molecule goes forward and how it goes forward. It's a slightly smaller sample size. Confidence intervals might be a little bit wider but we should have some understanding.

Got you. And then just a final question on [indiscernible], so details around data next year, et cetera. And -- but what indications should we be thinking about? Is that going to be predominantly non-small cell lung cancer?

So too early to comment on any specific indication, I would just observe that EGFR is a widely expressed tumor antigen with a lot of unharnessed potential, I would say, across many different tumor types. So we're excited about this product candidate. And as we mentioned, the Phase I design is a dose escalation in solid tumors initially and together with our partner, Amgen, one could envisage some further focusing of that study over time into specific tumor types, obviously, that express EGFR, of which there are many.

Okay. Thank you so much.

You're welcome.

At this time, I would like to hand the call back over to Chau Cheng for his closing remarks.

On behalf of the executive team, I would 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.

This does conclude today's conference call. Thank you all for participating. You may now disconnect. Have a great day.