Greetings and welcome to the BioAtla First Quarter 2024 Earnings Call. At this time, all participants are in a listen-only mode. A brief question-and-answer session will follow the formal presentation. [Operator Instructions] As a reminder, this conference is being recorded. It is now my pleasure to introduce your host, Bruce Mackle, with LifeSci Advisors. Thank you, Bruce. You may begin.

Thank you, operator, and good afternoon, everyone. With me today on the phone from BioAtla are Dr. Jay Short, Chairman, CEO and Co-Founder; Dr. Eric Sievers, Chief Medical Officer; Sheri Lydick, Chief Commercial Officer; and Richard Waldron, Chief Financial Officer. Following today’s call the team will participate in a short Q&A. Earlier this afternoon, BioAtla released financial results and a business update for the first quarter ended March 31, 2024. A copy of that press release and corporate presentation are available on the company’s website. Before we begin, I’d like to remind everyone that statements made during this conference call will include forward-looking statements, including, but not limited to, statements regarding BioAtla’s business plans and prospects and whether it’s clinical trials will support registration, plans to form collaborations and other strategic partnerships for selected assets; achievements of milestones, results, conduct, progress and timing of its research and development programs in clinical trials; expectations with respect to enrollment and dosing in its clinical trials, plans and expectations regarding future data updates, clinical trials, regulatory meetings and regulatory submissions, the potential regulatory approval path for its product candidates; expectations about the sufficiency of its cash and cash equivalents to fund operations and expectations regarding R&D expenses and cash burn. These statements are subject to various risks, assumptions and uncertainties that can cause actual results to differ materially and are described in the filings made with the SEC, including the most recent quarterly report on Form 10-Q. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of today, May 14, 2024, and BioAtla disclaims any obligation to update such statements to reflect future information, events or circumstances, except as required by law. With that, I’d like to turn the call over to Jay Short. Jay?

Thank you, Bruce, and thanks to everyone for joining us for our first quarter 2024 BioAtla earnings call. Additional details related to what we will share today are available in today’s press release and our updated company presentation, both of which are available on our website. We continue to make considerable progress across all of our ongoing clinical programs. We are pleased to share our recent encouraging data readouts for our CAB-ROR2-ADC and highly treatment refractory head and neck cancer patients, who had a median of three prior lines of treatment. As illustrated in the best overall response slide of our corporate presentation, many patients achieved rapid and deep tumor control with 38% of patients responding. Having observed an 86% disease control rate, we believe these findings support use in earlier line settings. In addition, in view of the manageable safety profile, this holds considerable promise for future combination therapies. Given the strength of the data we observed with CAB-ROR2-ADC, especially at the more intensive 2Q3W dosing regimen. We plan to meet with the FDA in the second half of this year for guidance on a potentially registrational trial. We obtained multiple responses in encouraging clinical benefit using the less intense Q2W dose of our CAB-ROR2-ADC and melanoma. However, we did not meet our internal bar. We do believe, though, that our CAB-ROR2-ADC at the more intensive regimen has potential in melanoma and other indications, including triple negative breast cancer, where we observed tumor reduction in our earlier Phase 1 study. However, due to our ongoing prioritization, we do not plan to explore the more intensive regimen at this time. Next, I will cover our ongoing Phase 1/2 trial with our CAB CTLA-4 IO antibody. Our Phase 1 study, which was expanded to a higher dose due to the encouraging…

Thank you, Jay. Beginning with our CAB-ROR2-ADC ozuriftabmab vedotin in the target agnostic head and neck cancer indication, we have enrolled a total of 33 patients, who had a median of three prior treatment regimens. Ranging from one to six prior lines of treatment, 21 received more intensive day 1 and 8 dosing in three week cycles, and twelve received every other week dosing. Among the 29 who were valuable for response assessment, eleven responses were documented and five responses are now confirmed to date. Notably, four of five confirmed responses occurred in patients, who received the ADC as second or third line therapy. Further follow up will be required to provide a reliable estimate of the response duration. Importantly, responses were observed regardless of ROR2 target expression from pre-treatment tumor biopsies evaluated by immunohistochemistry. As of the safety data cut in March, only one patient discontinued treatment due to a treatment related adverse event, which was peripheral neuropathy. Collectively, these data support advancing to earlier lines of therapy, potentially in combination with PD-1 inhibition in the first-line setting. A meeting with the FDA is anticipated in the second half of the year to discuss potential registrational trial approaches. Moving now to our CAB CTLA-4 antibody evalstotug. Over the past 25 years, multiple lines of clinical evidence have shown that increased exposure of CTLA-4 blockade in combination with PD-1 inhibition drives long-term survival benefits. At the same time, most oncologists prescribe currently approved CTLA-4 blocking antibodies at relatively low doses because a high rate of immune-related adverse events limit tolerability. We designed evalstotug to preferentially bind CTLA-4 in the acidic tumor microenvironment to avoid binding in normal healthy tissues and lymph nodes. We believe evalstotug will be better tolerated, enabling more patients to receive clinical benefit from CTLA-4 inhibition. Last…

Thank you, Eric. And good afternoon everyone. Continuing with our CAB CTLA-4 antibody, evalstotug, based on our evolving Phase 1 data, we continue to believe evalstotug has the potential to be better best-in-class CTLA-4 that holds the promise to be used as often as a PD-1 inhibitor and potentially expand the indications where combined immune checkpoint inhibition can be effective. There is tremendous opportunity across many solid tumors for evalstotug, but we are focused initially on BRAF-mutated metastatic melanoma as a potential efficient path to approval with a high likelihood of success. The current worldwide therapeutic market size of metastatic melanoma is approximately eight billion annually and is expected to grow to over 11 billion by 2028. BRAF mutations are present in approximately 50% of malignant melanoma patients and first line standard of care remains immunotherapy regardless of BRAF status. As Eric noted earlier, documented clinical benefits of adding an anti-CTLA-4 to a PD-1 inhibitor are particularly striking in BRF mutated patients and we believe that the combination of evalstotug with a PD-1 inhibitor, has the potential to become the standard of care for these patients. Onto our CAB ROR2 ADC ozuriftamab vedotin. We are encouraged with the single agent clinical profile that is emerging in multi refractory, heavily pretreated head and neck cancer. The worldwide prevalence and mortality rate for this population are significant, and despite recent advances, there remains a profound unmet need, particularly for patients who have progressed on first line treatment options. Therapies available for these refractory patients are limited and have suboptimal clinical benefits. The current worldwide therapeutic market size of head and neck cancer is approximately 3.5 billion annually and is expected to grow significantly to nearly 5 billion over the next five years. Given the encouraging emerging data set in head and neck cancer, we believe ozuriftamab vedotin could represent a significant commercial opportunity for BioAtla. We also believe ozuriftamab vedotin is well positioned for a strategic collaboration that will expand the potential of this CAB ADC across multiple solid tumor indications. Given the combined prevalence of head and neck cancer and BRAF-mutated melanoma, we believe these assets and indications represent potentially meaningful value creating opportunities for BioAtla with the potential to redefine standard-of-care for patients with these devastating diseases. With that, I would now like to turn the call back over to Jay.

Thank you, Sheri. Next, a few words in our potentially first-in-class, dual CAB, bispecific T-cell engager antibody CAB-EpCAM, CAB-CD3. EpCAM is a ubiquitous target expressed on the surface of cancer cells, which requires the use of our CAB technology to achieve optimal selectivity and safety. We are on track to report the full data set from the Phase 1 study in the second half of this year, with a potential Phase 2 study initiating also in the second half of this year. The T-cell engager space offers tremendous opportunity for more effective therapies and in particular, our CAB enabled EpCAM T-cell engager has the potential to treat patients with a wide range of metastatic tumors, including cancers of colon, lung, breast, pancreas and prostate, among others. BioAtla has developed a novel NextGen carbohydrate linker system to further reduce the potential risks associated with neutropenia from off target toxicity used in our CAB Nectin-4 ADC. This ADC has the potential for broad applicability, including for do indications such as pancreatic cancer. We recently presented compelling antitumor activity, PK and toxicology data last month at the AACR annual meeting that indicates CAB Nectin-4 ADC is potentially a more effective treatment with reduced toxicity. As part of today’s update, we have received FDA IND clearance for this agent and are evaluating several options as we continue to focus our resources on our later stage clinical programs. With that, I would now like to turn the call over to Rick to review the first quarter 2024 financials. Rick?

Thank you, Jay. Research and development expenses were $18.9 million for the quarter ended March 31, 2024, compared to $21.7 million for the same quarter in 2023. The decrease of $2.8 million was primarily due to completion of preclinical development related to our Nectin-4 IND and prioritization of our clinical programs in 2023. We expect our R&D expenses to continue to decrease in the near-term due to recently completed enrollment in clinical trials for datasets expected to enable potentially registrational trials for our ADC programs. General and administrative expenses were $5.6 million for the quarter ended March 31, 2024, compared to $7.2 million for the same quarter in 2023. The $1.6 million decrease was primarily due to lower stock-based compensation and professional fees. Net loss for the quarter ended March 31, 2024 was $23.2 million, compared to a net loss of $27.4 million for the same quarter in 2023. Cash and cash equivalents as of March 31, 2024 were $80.6 million, compared to $111.5 million as of December 31, 2023. Net cash used in operating activities for the quarter ended March 31, 2024 was $30.8 million, compared to net cash using operating activities of $22.7 million for the same period in 2023. Our cash used for the quarter ended March 31, 2024 included approximately $5 million in annual payments that typically occur during our first fiscal quarter. We expect our operating cash burn to be approximately $20 million for the quarter ending June 30, 2024, and to continue to decrease in the second half of the year as we complete treatments in our ADC clinical trials, allowing our current cash and cash equivalents to fund operations into the second half of 2025. And now, back to Jay.

Thank you, Rick. We are pleased with the considerable progress we have made to date and our cumulative results across our CAB pipeline targeting solid tumors. We look forward to the multiple important milestones this year, including several planned meetings with the FDA to discuss our potentially registrational trial with ROR2 in head and neck cancer, guidance on the remaining portion of the registrational trial in UPS with AXL, and guidance for a potentially registrational trial with CTLA-4 in BRAF mutated melanoma. With that, we will turn it back to our operator to take your questions.

Thank you. We will now be conducting a question-and-answer session. [Operator Instructions] Thank you. Our first question is from Brian Cheng with JPMorgan. Please proceed with your question.

Hey guys, thanks for taking our question this afternoon. Can you elaborate on the duration of the confirmed responses that you’re seeing with your raw two ADC in head and neck today? And what is your expectation on the duration response as the data set mature?

Thanks, Brian. I’ll let Eric take a crack at this one. Thank you.

Thanks, Brian. So we definitely need further follow-up to estimate our duration of response, but I will refer you to Slide 29 of our updated corporate deck, the swimmers plot gives you a sense of the confirmed responses and addresses the question you asked, particularly the patients that were treated at the every other week dosing. I will note that those patients were dosed first and then after completing that effort, we then went on to employ the days one and aid [ph] regimen. So we have a bit longer follow-up for the patients in blue on Slide 29.

And I’ll just add there are eight patients still on treatment and that are ongoing of which two have responses that could confirm, and there’s also two with decreasing tumor volume.

Great. And then maybe can you help us also frame the expectation of response level and also the duration of response with the current standard of care in head and neck today in second line and also third line.

Yes. So I think when you look at the later lines, we’re thinking if you could get four months plus in these – keep in mind, we’re fourth line here, three prior line – median three prior lines. So this is really out there. The bar is exceptionally low, especially when you look at second line, where you’re getting on, from a response rate standpoint 13% on average. And so there you would like to see, I think five months plus, obviously, go to first line, you’d like to see a half a year plus. But I think given the late lines we’re in, I think that it’s encouraging.

Great. Thank you so much.

Thank you. Our next question is from Kelly Shi with Jefferies. Please proceed with your question.

Hi everyone, thank you for taking our question. This is Dev on for Kelly Shi, and congratulations on the progress. I have a couple of questions on AXL. Can you provide any color on median follow-up that you might need before you meet with the FDA in second half? And also, do you expect to start the next stage of recruiting in 2024? Or it could be in early 2025. Thank you.

Thank you. Yes. Because we’ve completed the dosing that we intended for the first portion of the potentially registrational trial, our main goal here is to achieve multiple scans for each of those patients, which we think should readily occur in the second half of this year. And so our current thinking, assuming we got encouraging – continue to get encouraging data that we would have an opportunity to start that next portion of the – remaining portion of the registrational trial in late 2024.

And one more on non-small cell lung cancer randomized Phase 3 trial. Can you remind whether you started those trial in second line or third line, or do you need any more alignment with the FDA?

Well, on the non-small cell lung cancer, if I recall correctly, median of three prior lines there. So it was pretty late, very refractory patients, and we reported that out in December of last year, and we’ve done an extension to that study to look at the target agnostic patients. So we’ll give – we’ll have that data in still later this quarter, and we’re going to pick an appropriate way to communicate that data once we get to the end of this quarter. And so – and then I think from there, I think we’ve already got feedback from the FDA on how to proceed if one goes into a second line or a third line, which obviously is earlier than what our data comes from. So we feel that with that final data, we’ll be well-positioned to layout the final strategy for that, either independently or with partners.

Okay. Thank you. Thanks for taking our question.

Thank you. Our next question is from Kaveri Pohlman with BTIG. Please proceed with your question.

Great. Good evening. Congrats on the progress and thanks for taking my questions. For ROR2 ADC in head and neck. Can you tell us what feedback you received from physicians on this data? And were there any patients who had seen any other vedotin ADC as prior line of therapy, whether it’s PADCEV or Tivdak. Also, how you are thinking about the competitive landscape in general.

Thanks, Kaveri. It’s Eric answering. So, first, your question about the feedback we’ve gotten from physicians, I’ll just give you some anecdotes. We received a call from the PI at USC indicating how pleased he was to report a complete response, and that’s now confirmed and enabling the patient to go back to work. And that’s a patient that we review in our corporate deck. We were also pleased to hear from Memorial Sloan Kettering, where two of the investigators spoke about several patients on treatment, particularly emphasizing the tolerability and the rapidity of response. They felt that it really was serving an unmet need in this second, third and fourth line, head and neck cancer, which is exceptionally challenging, and so many patients having clinical progression as they’re getting these therapies. And then you asked the question about did prior treatment with one of the other auristatin based ADCs. When I looked through the prior treatments, all patients had received a PD-1 blocking agent. Many received either a platinum or – and/or a taxane regimen. I didn’t see any anecdotes of people that had received prior ADCs, but it’s certainly an interesting question with regard to the studies that are ongoing.

Yes. And Kaveri, this is Sheri. I can – if I could take the question on the competitive landscape. Obviously, within the existing competitive landscape, there remains a profound unmet need and patients who fail frontline options, as you know, in second line cetuximab is often used with an ORR 13%. So we think – within the existing therapeutic landscape that there remains an unmet need. And even if you look at the future competitive landscape, we have a different mechanism of action than those that are in development. And we think that the profile that’s emerging in this very heavily pre-treated patient population, really, really provides the opportunity for us to benefit patients in the second line setting within the existing as well as the future competitive landscape.

Got it. That’s very helpful. And maybe a question on the dosing regimen, I guess, this is for both active and ROR2 ADC. You’ve tested different regimens from your initial schedule of Q2W to 2Q3W. Is this just for Project Optimus? Can you tell us what has been learned regarding the profile of the drug from these studies, whether you saw any significant PK/PD differences with these regimen and how you are thinking about dosing schedule going forward?

I’ll just start off by saying and I’ll let Eric finish this, but I just want to say, I’ll remind us all that we did use the 2Q3W in Phase 1, so it’s not that new. It’s certainly one we’ve looked at. But with respect to 2Q3W, certain characteristics, I’ll let Eric add to this.

Sure. Thanks, Jay. So I’ll emphasize that both of the regimens, I think, are exceptionally well tolerated. I’ll refer everyone to Slide 35 of our corporate deck, where we’ve summarized the every other week dosing the 2Q3W, which is days one and eight of a three week cycle, and then for melanoma as well. And in here, we’re having very few instances of related AEs leading to treatment discontinuation. And so tolerability is excellent with both regimens. We are seeing in the head and neck data in particular, I think you can see from the spider plot on Slide 28 just a sense that we get more rapid disease control in the red, which is the more intensive regimen than the blue. And it is interesting with the blue patients, they did have longer exposure because we did those patients first. There are quite a few patients. There are the two instances of patients that are at many, many weeks of therapy, one passing 35 weeks and one passing 45 weeks on study. So I think both regimens well tolerated and the PK/PD, no surprises there. So looking good.

That’s helpful. Thanks for taking my questions.

Thank you. Our next question is from Arthur He with H.C. Wainwright. Please proceed with your question.

Hey, Jay and team. Good afternoon. Thanks for taking my question and congrats on the data in the head and neck. I just had a couple of questions for the head and neck data. So first – so I record you mentioned you want to go for a first line for these ROR2 ADC. First, I just want to get gauging your priority here for the future or still depending on the discussion with the FDA in the second half.

Thank you, Arthur. I appreciate it. We haven’t made a formal decision about whether we’re going to target first or second or both yet. Our vision is that we’d like to go to the agency and discuss trial designs for both. For the first line, I think that the auristatin based ADCs park pair remarkably well with PD-1 blockade. And so I think it’d be really an excellent combination with PD-1 antibody in the first line patients that received just the PD-1 antibody alone. And then we could, of course, do a Phase 1 evaluation in combination with platinum PD-1 to further enable that. Moving to second and beyond. Second and beyond line, there’s an enormous unmet need, and we see a relatively straightforward trial design where we would compare either against cetuximab monotherapy or potentially a limited number of chemotherapy or cetuximab choices for the investigator with a PFS endpoint that might possibly enable an early review of the trial data and accelerated approval, and then with an OS endpoint that would confirm in the same trial. So these are the possibilities that we are looking forward to exploring with the agency.

Thanks, Eric. Very helpful. And regarding the data, it seems like the 2Q3W has a better response compared to the Q2W. And I’m just curious, have you looking into the HPV expression marker in these patients, is there any correlation regarding the response rate with the HPV expression there?

Yes, it’s a great question, Arthur. We have not seen a correlation with HPV expression. It’s something that we’re going to continue to look at very closely. Those patients receive therapy that’s a little bit different. There’s some recent data suggesting they can deescalate the aggressive early therapy. And so we’ve been guided by our investigators to think of them as a little bit different than the HPV negative population. But right now, not seeing any obvious correlations. And I’ll just add that we’re also not seeing obvious correlations with the ROR2 expression, because that’s often a question that people ask us, and so we’re not needing a companion diagnostic at this time.

Got you. If I may, for the CTLA4 program for the upcoming data for the monotherapy this quarter, could you give us a little bit more color on the cancer type for those 20 patients as well as of now, what’s the medium cycle number as patient received the drug?

Okay. So moving to the conditionally binding CTLA-4 and you’re asking about the monotherapy. We open the doors very wide to melanomas and relapsed, refractory carcinomas. So I would anticipate a very broad number of different one single patients with different unusual cancer diagnoses that sometimes weren’t eligible for other clinical trials that were participating in the monotherapy experience. Our overall goal with the monotherapy was to clearly characterize the safety profile at both 300 and 700 milligrams. And I’m also happy to say that today we treated the third patient at the 1-gram dosing level. So we’ve now infused all three of the individuals at the very high dose level of 1-gram, which is 14.2 milligrams per kilogram based on a 70-kilo adult. So we’re looking forward to the ASCO presentation on June 1st and then a subsequent presentation to describe the outcome of these monotherapy patients that you’ve just asked about.

Great. Thanks, Eric. Thanks for taking my question.

Thank you. Our next question is from Tony Butler with EF Hutton. Please proceed with your question.

Yes. Thanks very much. I’d like to go back to the previous question, if I may, and part a, again, this is with CTLA-4. Will there be or do you anticipate, I assume you will that the combination with pembro at 1-gram will have been sufficiently – have sufficient duration before you make a decision about moving forward. In the BRAF mutated melanoma study that’s part one. And part two of that is apparently from the comparator arm, you’re making some judgments that there may be other types of agents that could be utilized other than pembro. And I’m just curious, does this end up simply being physicians choice and frontline? And then I have one more follow up, if I may? Thank you.

So why don’t I take these in sequence? The very first question you asked is, will we have sufficient follow up? And we believe we will. So I want to affirm that we are currently dosing patients with newly diagnosed melanoma, metastatic or unresectable melanoma, and presently, without regard to BRAF mutation, it to gain additional experience at this dose level. So these are first line patients. I just want to emphasize that, because that is then going to then lead into the proposed pivotal trial. Your second question is a really interesting one, and I think that agency feedback will be necessary here. I want to remind everyone that there are four strategies that could be employed for newly diagnosed metastatic or unresectable melanoma, and they include nivolumab, pembrolizumab both of those as monotherapy, opdualag or the combination of nivolumab plus ipilimumab. And so vision presently is that we’d like to run a blinded, randomized study against pembrolizumab because it represents a currently labeled opportunity. And it’s notable that several other sponsors are using pembrolizumab monotherapy as the comparator arm in their frontline melanoma trials.

Eric, thank you for the follow-up or the commentary. My follow-up question is on the Nectin-4 ADC with the carbohydrate linker. Just mechanistically, does the carbohydrate linker limit the number of the payload that you can actually add to the antibody? And if you say no, that’s fine. But the question is, what is the DAR today? Is that the most optimal payload for the Nectin-4 ADC? Thanks very much.

I’ll take that one, Tony. Basically, the actual design of our carbohydrate linker system allows us to increase above the DAR 4. So actually that current Nectin-4 ADC is DAR 6. And we’ve seen very good safety profile. We think it’s going to add to the safety profile because if it’s going to help us to reduce off target talks. In addition, it’s also a cab, so further reduces on target talks. So we’re really bringing these two pieces together and in a very specific way because Nectin-4 the marketed compound is known to have various toxicities, and one of those is significant is a rash. And so we, at least from the animal data and for modeling, suggest that we have a therapeutic index that should allow us to be able to reduce, if not totally eliminate the rash, and we’ll just have to see the data further. We’re kind of – we’re excited about this drug because we’ve also noticed that we’ve been enabled – had the ability to enable additional targets not traditionally associated with Nectin-4 activity, and one of those is pancreatic cancer. And we do know that this observation is linked in part to our carbohydrate linker and the cab and carbohydrate linker working together. However, in saying all of this, I want to emphasize that there’s no way, I think, is saying that the carbohydrate linker is better than what we’ve seen at the peptide linker and AXL and ROR2 because we had a very specific toxicity to resolve Nectin-4. We are seeing very safe profile without those kind of toxicities with our AXL and ROR2 drugs. So I think, in a way we came in to this program with a very specific purpose to address a very clearly defined toxicity. And so in combination you have a chance here to go into an indication with a very low bar with safety that could potentially allow this drug to go quite wide. And I’ll just add, I think one nice thing about it is that you should get these results very quickly because there’s a known level of dosing. And so with Phase 1, you should learn both your safety and your efficacy adequate to really validate this compound, so an exciting asset.

Jay, it’s fantastic. Thanks very much.

Thank you. There are no further questions at this time. I’d like to hand the floor back over to Jay Short, CEO, for closing comments.

Thank you everyone for your attendance today and continued interest in BioAtla. We’re obviously very encouraged by our data and very hopeful and a lot of drugs that I think are on the precipice of being able to bring to market. So hopefully it continues. And thank you for your attention.

This concludes today’s conference. You may disconnect your lines at this time. Thank you for your participation.