Good afternoon, ladies and gentlemen. Thank you for standing by. Welcome to the CytomX 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, Chau Cheng, CytomX's 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, CytomX'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 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 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 within our clinical and preclinical programs and operations. At CytomX, 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 are 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 market. 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 continued to advance our broad pipeline of Probody therapeutics across multiple modalities and cancer types, including our two conditionally activated antibody drug conjugates or ADCs praluzatamab ravtansine, also known as CX-2009 and CX-2029, both of which are currently in Phase 2 clinical investigations encompassing multiple tumor types. Let me begin with CX-2029, our CD71-directed conditionally-activated ADC, for which we recently published results from a Phase 1 first-in-human study in patients with advanced solid tumors. This important work by CytomX, 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…

Thanks, Sean. I'll start with a quick recap of the design for our Phase 2 studies of CX-2029 and praluzatamab. For CX-2029 in collaboration with AbbVie, we continue to enroll patients into the expansion phase of the Phase 1/2 study designed to evaluate the CD71-directed, conditionally activated ADC in four different cohorts: squamous non-small cell lung cancer, head and neck squamous cell carcinoma, esophageal and gastroesophageal junctional cancer and disease like B-cell lymphoma. Each cohort aims to enroll up to 25 efficacy evaluable patients and we continue to expect initial data from the expansion phase of the study in the fourth quarter of this year. Switching to CX-2009 or praluzatamab ravtansine, we are evaluating the CD166 directed conditionally activated ADC as monotherapy in patients with HER2 non-amplified breast cancer, which includes hormone receptor positive Arm A, and triple-negative breast cancer Arm B. We are also evaluating the combination with our proprietary anti-PD-L1 therapeutic pacmilimab in patients with triple-negative disease in Arm C. The goal is to reach 40 efficacy evaluable patients in each of these arms. And the primary endpoint of this study is overall response rate according to resist. Secondary endpoints include duration of response and clinical benefit rate at 24 weeks, the latter being particularly an important metric for the hormone receptor positive subtype as a reasonable surrogate to support progression-free survival endpoints in future studies. Enrollment is ongoing. However, our accrual rate for our fourth quarter 2021 initial data readout has been slower than expected, due primarily to the widespread effect of the COVID-19 pandemic on site activation and on patient enrollment. The praluzatamab Phase II study is a new trial, requiring de novo site activation and this has proven particularly challenging in the current environment. As such we now anticipate initial data from this study in…

Thank you, Amy. With $366 million in cash, cash equivalents and investments, as of June 30 2021, CytomX remains well capitalized to support our bold clinical and research agenda that will drive the growth of the company well into 2023. Revenue was $16 million for the second quarter of 2021, relatively flat when compared to the corresponding period in 2020. R&D expenses increased $2 million to $26 million, during the three months ended in June 30 2021, compared to the corresponding period in 2020. The increase was driven mainly by planning of manufacturing and translational science activities. G&A expenses were $9 million for Q2 2021, essentially flat compared to the second quarter of 2020. With that I'll turn the call back to Sean.

Thanks, Carlos and thanks to everyone for joining us today. To briefly recap, CytomX continued to make broad progress in Q2 across our pipeline and platform. We currently have four novel Probody assets in Phase II studies, across nine cancer types with readout starting at the end of this year with CX-2029. We also continue to develop our core technology across multiple biologic modalities, as we advance new clinical candidates into development. Our recently published work highlights the scope and scale of our R&D efforts, as we drive our pipeline forward and invest in our technology for the long term. With that let's open up the call for questions. I'll turn it back to the operator.

[Operator Instructions] Our first question comes from the line of Anupam Rama from JPMorgan. Your line is now open.

Hey, guys. Thanks so much for taking the question. For CX-2029, can you remind us the size and scope of the data we'll be getting here in 4Q? And remind us, if this is going to be at a medical meeting, or should we be thinking about more of a top line press release webcast-type scenario? Thanks so much.

Hey, Anupam. How are you? Good to hear from you. So we're guiding to initial data from the expansion phase by the end of the year. We haven't pinpointed any particular venue or methods through which we would communicate that data. As Amy mentioned, there are four cohorts in this expansion phase, the head and neck, the lung, the esophageal and the DLBCL. We are anticipating initial data from at least one of these cohorts by the end of this year. We're on track. And as I said, we haven't guided exactly where that would be.

Thanks for taking my question.

Our next question comes from the line of Roger Song from Jefferies. Your line is now open.

Great, thank you. Very similarly the question for that CX-2009. So what should we expect in the initial readout, because I remember last quarter, you say the initial data from the Arm 1 and B -- A and B and that should we also expect to Arm A and B as the initial data. Also you broadly guide to 2022, can we have some granularity in terms of first half or second half of 2022, when should we be expecting the data?

Yeah. Hi, Roger. Thanks for the question. So yes, so just again just to recap Arm A is hormone receptor positive, Arm B is triple-negative just like monotherapy, Arm C is the combination with our proprietary PD-L1 Probody pacmilimab. So the revised guidance remains for Arms A and B in 2022. Arm C, it's like at this point, we're not going to be more specific than that. I think given the evolution of the macro environment and just the uncertainties around COVID, we're going to keep that guidance pretty broad right now. We do have though, I can say through 2009, we are making progress, we do have more than 20 sites open for the study, so we have the team has made a lot of progress, we need to make more and every day is a new day in the current world. In terms of Arm C, the combination with pacmilimab, we're pretty consistent with the guidance that that would be slower than Arms A and B, given that we're screening for both CD166 and PD-L1 that's going to be a smaller patient population. We'll have to see how that develops. We'll provide additional guidance as time moves on the timing of Arm C.

Yeah, I understood. Yeah everyday is a new day. So maybe just another question from me is the earlier pipeline program during something like the cytokines derivative program, which is very exciting, just any updates from that?

Roger, could you repeat which program. I didn't quite get it?

Yeah. Just any update for your cytokine derivative program and any other kind of earlier program?

Yeah, you bet. And as I mentioned in my remarks, we're really excited about where we are on the platform. The work that we've done much of which we've now published in peer-reviewed form is demonstrating the utility of the Probody approach across multiple biologic modalities now extending in our most recent work to cytokines and into immune agonist antibodies with the PNAS paper on CD137. So we presented some work earlier this year on interferon alpha-2b, a really unique approach to marketing that cytokine, which I think there's general agreement that there is enormous potential for focusing or harnessing the clinical activity of that particular biology, if we can increase therapeutic window. Our preclinical data supports that we have open therapeutic window when moving that asset further into preclinical development. We're still in lead optimization, I would like to say, but certainly moving it forward. And we continue to look at bispecifics and we'll continue to apply the platform to drug conjugates to get undruggable targets, so a lot of potential. I also mentioned on the call, our EGFR CD3 program, which is really a big idea in bispecifics, we know from work that is previously published by Micromet some years ago that EGFR in CD3 bispecific form is a very difficult target to address. We're bringing our masking technologies there, so attempts to open a therapeutic window. And as I mentioned, we're working toward getting that IND on file by the end of this year.

Got it. Thank you for all the other comment. Thank you.

You are welcome.

Our next question comes from the line of Joe Catanzaro from Piper Sandler. Your line is now open.

Great, thanks so much for taking my questions here. So, I mean, you had mentioned that for CX-2009, it was a new study that required new site initiations, so it sounds like in contrast 2029, the Phase II cohorts just rolled over from the Phase I and didn't require new site initiations, can you confirm that and is that the case for all expansion cohorts or did some tumor types, i.e. DLBCL requires some new sites to open up and enroll patients. Thanks.

Sure. Thanks, Joe for the question. Yeah. To confirm the 2029 study was designed as a Phase 1/2 study with expansion continuing at sites that were open, which allowed us to continue enrollment. As you point out, there are interesting novel cohorts and we did look at activating new sites to help boost enrollment, but the continuation of enrollment was allowed primarily due to the continuation of the study at the already open activated sites.

Okay, got it. That's helpful. And then I think you guys had previously guided toward data potentially by the end of the year from both the lung cancer and head and neck, but it sounds like, may be you backtrack a little, if I heard correctly that we could expect at least one cohort worth of data of the four?

Yeah, I wouldn't describe that as much as a backtrack, Joe. I think we're generally on track with prior guidance.

Okay, got it. That's helpful. Thanks for taking my question.

You bet.

Our next question comes from the line of Boris Peaker from Cowen. Your line is now open.

Hi thanks. This is Cynthia on for Boris. For CX-2009 are you still seeing around 50% of patients triple-negative patients expressing CD166 at a high level? And then just speaking through for Arm C, are you getting a sense of how many triple-negative patients express both CD166 and PD-L1?

Yes, great question. We continue to evaluate target expression across these arms in the Phase 2 study. Nothing to really comment on right now but that continues to be an important component of the study as we continue to learn and we'll continue to learn about the relationship between CD166 expression and response and the CD166 expression across these different patient populations. So, it continues to be very much work in progress.

All right, great. Thank you.

Our next question comes from the line of Etzer Darout from Guggenheim. Your line is now open.

Great. Thanks for taking the question. This is Paul on for Etzer. Just one from us. for your EpCAM program the CX-2043. Have the supply chain issues you sort of discussed last quarter have been resolved? And is there any update to your IND plan for this program? Thanks.

Yes. Thanks for the question. And I actually neglected to mention EpCAM while I was doing my recap of our early pipeline earlier on in response to Roger's question. Yes, so we've made progress there. And just to recap the challenge that we ran into was relating to the DM-21 payload which is a next-gen maytansinoid. We've made a lot of progress there. We're still looking at what that time line is going to be. So, there's no formally-updated guidance but we are making progress with the program and with EpCAM generally as a target which we continue to be highly interested in.

Great. Thanks so much.

Our next question comes from the line of Peter Lawson from Barclays. Your line is now open.

Thanks. Just on I guess the CD71 data, I'm just trying to piece it together. So, I think last time you got you were suggesting that the head neck and the lung would be at the end of the year. Is that still the case? And then DLBCL kind of next year? Is that the right order? And do we get kind of data sets year-end for at neck and lung.

Yes. So, the -- again those four cohorts of head and neck lung, esophageal and DLBCL. The first two were obviously selected based on data that we saw in the Phase 1 dose escalation activity that we saw in Phase 1 and obvious choices for Phase 2 expansions. And I would say, yes, generally, on track for those two cohorts to present updates by the end of the year and with the others following thereafter.

Got you. And the venue for that would be more of a press release than a conference?

We haven't disclosed the strategy at this point Peter. We'll provide further information as we go further through the year.

Got you. And the breast cancer delayed like triple-negative and HR-positive HER2-negative was that predominantly driven by these kind of new site inactivations or was there anything else that we should be thinking about?

Yes, it's really a COVID thing. And as I said we've got a pretty decent number of sites open. A lot of those have come on fairly recently. The team is really working all hours to get this -- to bring this study in. We're excited about this asset. We want to see this data as much as anybody else. But it's a tough operating environment right now to get new sites initiated. I think you'll be hearing that from others. And that's -- we're certainly seeing a lot of enthusiasm from our investigators. I'll take you back to our analyst event earlier this year where you heard Sara Tolaney talk about the potential of praluzatamab ravtansine. And so yes, this is an operational challenge and we've just got to keep powering through.

Got you, okay. Thanks for the update.

You're welcome.

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

So, 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 for participating. You may now disconnect and have a great day.