BioAtla, Inc.

Greetings, and welcome to the BioATLA fourth quarter and full year 2022 earnings call. At this time, all participants are in a listen-only mode. A question and answer session will follow the formal presentation. If anyone should require operator assistance during the conference, please press star zero on your telephone keypad. Please note this conference is being recorded. I'll now turn the conference over to your host, Bruce Mackle. You may begin.

Thank you, operator, and good afternoon, everyone. With me today on the phone from BioAtlas are Dr. Jay Short, Chairman, CEO, and Co-Founder, Richard Waldron, Chief Financial Officer, and following today's call, Philippe Martin, Chief of Clinical Development and Operations, Eric Sievers, Chief Medical Officer, and Sherry Lydick, Senior Vice President, Commercial Strategy, will join Jay and Rick for a short Q&A. Earlier this afternoon, BioAtla released financial results and a business update for the fourth quarter and full year ended December 31st, 2022. A copy of the press release is 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, potential selective licensing, collaborations, and other strategic partnerships, whether our clinical trials will be potentially registrational, results, conduct, progress, and timing of our research and development programs and clinical trials, expectations with respect to enrollment and dosing in our clinical trials, plans regarding future data updates, clinical trials, regulatory meetings, and regulatory submissions, the potential regulatory approval path of our product candidates, expectations about the sufficiency of our cash and cash equivalents, and expected R&D and G&A expenses. 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 annual report on Form 10-K, and subsequent quarterly reports on Form 10Q. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of today, March 23rd, 2023, 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, okay?

Thank you, Bruce, and thanks to everyone for joining us for our fourth quarter and full year 2022 Biolabra earnings call. Biolabra has made significant progress in 2022 across our five ongoing Phase II trials for our two latest stage first-in-class CAB ADC product candidates, BA3011 and BA3021, targeting multiple solid tumor types. We continue the positive trajectory in 2023, intently focused on further advancing the development of our innovative clinical and preclinical programs across our platform, leveraging the broad applicability of our CAB technology across several clinical stage antibody types, including Axyl and Ward II ADCs, targeted CTLA-4, IO naked antibody, and our first dual-CAB bispecific EPCAM and CD3 T-cell engager. Before providing the update, I'd like to remind everyone that additional details related to what I'm going to present are available on our website as part of our updated company presentation that may be helpful to you. We are excited by the promising clinical responses to date that are generally meeting and in several cases exceeding our interim study target responses. However, we recognize the resulting impact from providing incremental data updates on small sample sizes. In view of the near-term completion of these studies, going forward, we plan to release more mature data sets across our programs. As a reminder, we are using these studies to provide sufficient data to allow us to set study parameters that maximize the company's likelihood of success for our phase two potentially registrational studies. While this communication approach will modestly affect our data updates for Q2, We do not anticipate that this will delay the overall program development timelines while we advance what I believe will be a transformational platform in the treatment of solid tumors. Let's now move to our clinical, operational, and financial updates for 2022, as well as our progress from the beginning of the year. In order to maximize the differentiated benefit-risk profile of our CAB ADCs, we've looked at different doses and dosing regimens throughout phase one and phase two part one. Based on the sizable data set we've accumulated, we were able to complete a thorough exposure response analysis leading to the selection of a more frequent dose-intensive regimen for our UPS phase two part two study. While the profile of the 1.8 milligrams per kilogram Q2W or once every two weeks dosing regimen is positive, The more frequent dose-intensive regimens at the 1.8 milligrams per kilogram, 2q3w, or twice in a three-week cycle, and the 1.2 milligrams per kilogram, 3q4w, or three times in a four-week cycle, which uses the 1.8 milligram per kilogram starting dose, are expected to provide approximately 38% and 44% more exposure respectively than the previous Q2W dosing regimen. Based on our exposure response analysis, we anticipate that these more frequent dose-intensive regimens will further improve anti-tumor activity while having similar or even improved safety profiles compared with the Q2W dosing regimen. This dose strategy was supported by the FDA as part of our UPS Phase 2, Part 2 study design discussions and is in alignment with FDA's Project Optimus. In view of these things, we continue to be excited about the first of our two lead assets, BA3011, for multiple indications. Previously, we shared the partial interim data on our BA3011 Phase II Part I Sarcoma Study and our BA3011 Phase II Part I Non-Small Cell Lung Cancer Study. Today, we're providing additional insights, including how we're applying the learnings from our encouraging safety data and exposure response analyses, as well as our UPS-related FDA interactions to study more frequent dose-intensive regimens more broadly across our AXL-ADC and ROR2-ADC programs. First, I will discuss our BA3011 Phase II sarcoma study and our overall sarcoma strategy. UPS is one of the largest sarcoma subtypes representing nearly 15% of all soft tissue sarcomas. It is also one of the most aggressive subtypes with one of the highest recurrence rates. There are currently no FDA treatments specifically approved to treat UPS, and patients tend to progress very rapidly. Thus, UPS represents a significant commercial opportunity as a standalone indication, and we are focused on moving quickly to registration in UPS. Last year was marked by continued strong execution, promising results with continued anti-tumor activity, lack of disease progression, and a differentiated safety profile of BA3011 in UPS. As an update to the Phase 2, Part 1 UPS study, we currently see an overall objective response rate, or ORR, of 50%, median progression-free survival, or PFS, of 11 months, and a duration of response exceeding 8 months. Based on these results, together with the continued differentiated safety profile and encouraging feedback from the FDA around the study design, we initiated part two of the potentially registrational portion of the trial. This month, the first six leiomyosarcoma patients cleared the DLT observation period using the 3Q4W dosing in part one of the phase two study, which was a study requirement to begin enrolling patients in phase two part two of the UPS trial. We now anticipate first patient in for this study soon in the first half of this year. These first 40 patients with a TMPS greater than or equal to 50% are now enrolling and will be randomized one to one between three Q4W or two Q3W dosing regimens. Following this, we plan to enroll an additional 40 patients at the selected dose to complete the study. Overall, the primary efficacy endpoint, ORR, will be based on approximately 60 patients treated at the selected dosing regimen. In addition to UPS, we continue to see positive anti-tumor activity across several soft tissue and bone sarcoma subtypes where we previously reported an observed PFS rate at 12 weeks of 60% in liposarcoma, 50% in synovial sarcoma, and 67% in osteosarcoma. We are very encouraged that all three subtypes continue to meet our predefined GO criteria to advance into part two of the phase two study. We also continue to enroll the remaining sarcoma subtypes. With respect to Lyomyosarcoma, as I mentioned earlier, we recently cleared the DLT observation period in the first six patients using the more frequent dose-intensive 3q4w regimen and are continuing this study in Lyomyosarcoma for 10 to 15 patients to evaluate this dosing regimen for potentially opening up a broad soft tissue sarcoma phase two study in the future. With regards to the safety profile across sarcoma subtypes, BA3011 continues to be generally well tolerated with a phase two safety profile consistent with the profile we observed in phase one. Given the encouraging anti-tumor activity we're observing, coupled with a significant unmet need, UPS represents a solid early indication for BioAtlas as we plan for the transition into a commercial stage company. We also see real value in potentially expanding our sarcoma footprint over time to include other sarcoma subtypes. Ultimately, BA3011 has the potential to treat over 25,000 sarcoma patients per year and generate up to $2 billion in revenue worldwide in this area. a very high unmet need. Regarding our DA3011 Phase II study in axopositive multi-refractory non-small cell lung cancer, we continue to be enthusiastic by the responses we're observing. There are limited treatment options for patients who progress on immune checkpoint inhibitors and available treatments in the second line of the onsetting. These patients have suboptimal overall ORRs of approximately 10% to 20%. As a reminder, part one of a phase two study in non-small cell lung cancer is ongoing in actual positive patients who have previously experienced failure of either PD-1, PD-L1, EGFR, or ALK inhibitors. The previously reported preliminary efficacy with an ORR of approximately 40% to 44% was observed so far in this study. This response rate is highly competitive in this PD-1 failure population and supportive of moving forward to the Phase II potentially registrational part of the study. Based on the preliminary interim observations, we believe BA3011 will be highly commercially relevant with an ORR well above current ORRs observed in a multi-refractory patient population. Further, leveraging our insights and FDA discussions on UPS, we expanded our phase two part one non-small cell lung cancer study to include the more frequent dose-intensive regimens 2Q3W and 3Q4W. We are currently enrolling these patients as we prepare our submission for a meeting request to confirm the design of the potentially registrational phase two part two study with the agency in the first half of this year. with feedback anticipated in the second half, complete with the final dose selection. We anticipate reporting all of these data after the phase two part one is effectively complete, which is anticipated in the second half of 2023. Most importantly, we also expect that we will initiate the potentially registrational study in non-small cell lung cancer in the second half of this year, preserving our overall timeline for development of the non-small cell lung cancer indication. With respect to market size, a significant proportion of non-small cell lung cancer patients express Axel. And we estimate that there are over 100,000 axopositive addressable patients per year worldwide. This second line plus indication has the potential to add approximately $2.5 to $3 billion in worldwide revenue at peak. Taking together sarcoma and mild small cell lung cancer, we believe BA3011 has the potential to become a significant commercial asset for bioalloy across multiple solid tumor types. Of even greater importance is that BA3011 has a potential to be a best-in-class treatment for a significant number of patients who fail multiple lines of therapy, thus filling a significant unmet medical need. To round out our CAB-ADC BA3011 program, we are supporting an ongoing multicenter investigator-initiated Phase II clinical trial BA3011 in patients with platinum-resistant ovarian cancer. We are anticipating interim data consisting of 10 patients in the second half of this year. Now turning to our second lead CAB ADC product candidate, BA3021, a CAB War II ADC. As a reminder, there are no other therapies targeting War II in the clinic, so we have the potential to have a first-in-class treatment for solid tumors. To date, we have three Phase II trials ongoing with BA3021, As previously reported in our phase one clinical data, we saw impressive responses in war two positive patients refractory to PD-1 therapy, including two PRs in non-small cell lung cancer, one PR in head and neck cancer, and one complete response in a melanoma patient who remains in complete remission off treatment for over two years. Based on a similar study, Exposure response analysis done in actual positive tumors. We are pursuing the same strategy in our phase two or two positive non-small cell lung cancer study and currently enrolling patients in the more frequent, more intensive dosing regimen of 3Q4W in the first half of this year and plan to share data when we have sufficient evidence to determine how to proceed with our potentially registrational study. Regarding the melanoma phase 2 trial in patients who have previously experienced failure of the PD-1 therapy, following an additional CR in an invaluable patient identified using our validated IHC assay, we are screening patients with a validated liquid biopsy and anticipate providing an enrollment update on or around the first quarter 2023 earnings call in May. In addition, our phase two head and neck study is ongoing in patients who have previously experienced failure of PD-1 therapy alone or in combination with platinum therapy. We have achieved first patient in for this study. So far, the observed VOR2 positivity rate is high and in line with our expectations. We anticipate providing an enrollment update on or around the first quarter 2023 earnings call in May. To round out, our CAB 80 CBA BA3021 program. We're supporting a multi-center investigator-initiated Phase II clinical trial of BA3021 in patients with platinum-resistant ovarian cancer. We are anticipating interim data consisting of 10 patients in the second half of this year. Now I'd like to talk briefly about our Phase I-II trial for CAB-CTLA-4 antibody BA3071. The Phase I-II trial is being conducted in tumors known to be responsive to CTLA-4 treatment and will evaluate safety and tolerability of BA3071 and monotherapy in a combination with nivolumab. The trial is progressing as planned. As part of today's update, I'm pleased to share that the DLT observation period was cleared for the fourth cohort at a dose of 210 milligrams or 3 mg per kilogram in combination with 3 mg per kilogram of nivolumab. No DLTs were reported. We are now progressing to the fifth cohort at 350 milligrams or 5 milligrams per kilogram as a monotherapy or in combination with 3 milligrams per kilogram in nivolumab and anticipate the planned phase 1 data readout in the second half of this year. Moving on to our earlier stage pipeline, namely our potentially first-in-class dual-CAB bispecific T-cell engager antibody, CAB, FCAM, and CAB CD3, or BA3182. We recently received FDA clearance of our IND for the treatment of advanced adenocarcinoma and are on track for the first patient in for the phase one study in the first half of this year, with a complete phase one data readout anticipated next year. Similar to our other three clinical CAB product candidates, This antibody holds much promise in view of the in vivo preclinical studies demonstrating an over 100-fold improvement in the therapeutic index relative to the non-cab variants due to the combined selectivity of the dual-cab design. Several of the most common subtypes of adenocarcinoma that have tremendous unmet need that we can potentially address include colon, lung, breast, pancreas, and prostate. BioATLA also continues to progress several candidates through IND-enabling studies, including CAB-my specifics and next-generation ADC antibodies, and we still anticipate IND submissions for additional candidates potentially this year and next. With respect to important ongoing communications, the company has seven accepted recent and upcoming poster presentations, including an ESMO, sarcoma, and rare cancers congress, the European Lung Cancer Congress, and AACR, the latter of which will include preclinical data related to next-generation ADCs and multiple bispecifics. With that, I would now like to turn the call over to Rick to review the fourth quarter of full-year 2022 financials.