BioAtla, Inc.

Good day, everyone, and welcome to today's BioATLA first quarter 2025 earnings call. At this time, all participants are in a listen-only mode. Later, you will have the opportunity to ask questions during the question and answer session. I will be standing by should you need any assistance. It is now my pleasure to turn the conference over to Bruce Mackle with LifeSci Advisors. Please go ahead.

Thank you, Operator, and good afternoon, everyone. With me today on the phone from BioATLA are Dr. Jay Short, Chairman, CEO, and Co-Founder, and Richard Waldron, Chief Financial Officer. Following today's call, Dr. Eric Seavers, Chief Medical Officer, and Sherry Lydick, Chief Commercial Officer, will join Jay and Rick in a short Q&A. Earlier this afternoon, BioAtla released financial results and a business update for the first quarter ended March 31, 2025. A copy of the 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 BioAtlas business plans and prospects, and whether its clinical trials will support registration, plans to form collaborations and other strategic partnerships for selected assets, results, conduct, progress, and timing of its research and development programs and 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, and expectations about the sufficiency of its cash and cash equivalents to fund operations and expected R&D 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 10-Q. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of today, May 6, 2025, and BioAtlas 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 Dr. Jay Short. Jay?

Thank you, Bruce, and thanks to everyone for joining us for our first quarter 2025 BioAtlas earnings call. 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. Also, the posters, which were recently presented at the 2025 AACR annual meeting, are available on our website. Just a few short weeks ago, I provided updates on our conditionally active biologic or CAB platform clinical programs that we are advancing internally at BioATLA. as well as the clinical programs we are currently advancing toward corporate partnerships. All of these CAB-based programs are designed to increase both the potency and safety of our therapeutic candidates, targeting solid tumors in areas of high unmet medical need. Today, I will begin with our Phase I Dose Escalation Study, evaluating the dual conditionally binding EPCAM and CD3 T-cell engager. As a brief update to our call in March, the study is progressing well and the maximally tolerated dose has not yet been reached. We continue to observe multiple patients achieving tumor reduction and tolerating the therapy over many months without progression. Further, all three patients in the 100-microgram treatment dose cohort have cleared the dose-limiting toxicity period. We have also dosed the first three patients at the treatment dose of 300 micrograms, and we remain on track for our dose escalation clinical data readout in mid 2025. We also anticipate a data readout for the cohort expansion portion of the study in the first half of 2026. We continue to believe that our dual-CAB-EPCAM, CAB-CD3 bispecific T-cell engager, has the potential to be at the forefront of a novel approach to harnessing the body's immune system to target and destroy cancer cells, and has the potential to treat a wide range of metastatic tumors, including cancers of the colon, lung, breast, pancreas, and prostate, among others. Next, on to our CAB Axel ADC, McVie. McVie continues to demonstrate exceptional overall survival at the 1.8 mg per kg Q2W dosing regimen with a two-year landmark survival of 59% in MKRAS non-small cell lung cancer patients. This is particularly compelling given the previous studies among patients treated with standard of care agents have reported a two-year landmark survival of only less than 20%. We continue to observe a high correlation of Axel and MK-RAS expression, and the study follow-up is ongoing. A particular note, We recently observed a similar exceptional overall survival using McVie across several subtypes of soft tissue sarcoma, including leiomyosarcoma, undifferentiated pleomorphic sarcoma, and liposarcoma, with a one-year landmark survival of 73%. Observing exceptional overall survival in two different heavily pretreated solid tumor types strengthens our conviction that MCV is fundamentally improving the natural history of the disease, enabling patients to live considerably longer regardless of the subsequent treatment they receive. We remain focused on positioning this asset for a future pivotal trial with Phase II data readout in the first half of 2026. Transitioning to the Phase II clinical programs that are planned for advancement through corporate partnerships, We remain committed to aligning with a partner that can maximize the value of these assets, and we are very encouraged by our active discussions with multiple potential collaborators. First, regarding our CABROR2 ADC, OSV, we continue to observe a compelling signal in patients with metastatic HPV-positive head and neck cancer. This group of patients represents a significant and growing segment of the head and neck cancer population with high unmet need. This large patient population is currently poorly served by agents that inhibit EGFR, as well as other standard of care agents. More specifically, other studies using standard of care agents have reported an ORR of only 0% to 3.4% among HPV positive head and neck cancer patients. As of the March 24th data cutoff, Eleven treatment refractory HPV-positive head and neck patients who had three prior lines of therapy treated with the 1.8 mg per kg Q2W dosing regimen showed a remarkable 100% disease control rate, a 45% overall response rate, with 27% confirmed to date. We continue to collect data on duration of response, median progression-free survival, and median mortality. overall survival, all of which are ongoing, and we plan to share these data at an upcoming medical meeting. So far, we have received timely responses from the FDA and are now utilizing our fast-track designation for additional discussions with the FDA regarding treatment refractory metastatic HBV-positive squamous cell carcinoma of the head and neck. We believe our extended experience with Q2W dosing of OSV also has the potential to satisfy Project Optimus requirements, and we plan to share our results with the FDA to seek confirmation regarding our proposed recommended Phase III treatment regimen. Moving now to our CAB C24 antibody, Avastatug. Partnering discussions are ongoing, and we continue to believe that Avastatug has the potential to be best in class with a differentiated clinical profile relative to other CTLA-4 antibodies. To date, we have observed a 67% overall response rate and a 92% disease control rate in 12 available patients with metastatic cutaneous melanoma. These results are notable given that 10 of 12 patients had received prior PD-1 adjuvant or neoadjuvant treatment. We look forward to sharing additional data updates at a medical meeting later this year. With respect to our ongoing clinical communications, I am pleased to report our progress with the medical and scientific communities as acknowledged with ongoing abstract acceptances at prestigious conferences, including the American Society of Clinical Oncology, the American Association of Cancer Research, and the Asthma Gastrointestinal Cancers Congress. Additionally, we are invited to give a presentation at the upcoming PEGS conference around our dual-CAB, EPCAM, and CAB CD3 bispecific T-cell engager. With that, I would now like to turn the call over to Rick to review the first quarter of 2025 financials. Rick?