BioAtla Investor Presentation Deck

Promising safety and tolerability profile emerging in NSCLC Phase 2 at the RP2D 1.8 mg/kg Q2W Characteristic Any Adverse Events (AES) Related AEs with CTCAE¹ Grade 3 or 4² Any related serious AEs² Related AEs leading to death² Related AEs leading to treatment discontinuation² bicatla Constipation Peripheral Neuropathy BA3011 (N=13) 11 (85%) 4 (31%) 2 (15%)* Diarrhea 0 1 (8%) ⁹ BA3011 + Opdivo (N=9) 6 (67%) 2 (22%) 2 (22%)^ 0 0 ■ ■ ■ ■ No treatment-related deaths Few treatment-related SAEs Grade 1-2 (9%) Grade 3-4 (0%) All Grade 1-2 (4.5%) Grade 3-4 (0%) Grade 1-2 (14%) Grade 3-4 (0%) Low-grade constipation observed is consistent with baseline levels seen in advanced cancer patients Interim data- Data cut-off of Oct 25, 2022 Note: ¹CTCAE: Common Terminology Criteria for Adverse Events. The NCI Common Terminology Criteria for Adverse Events is a descriptive terminology which is utilized for Adverse Event (AE) reporting. A grading (severity) scale is provided for each AE term. 2As assessed by the investigator. Missing responses are counted as related. *Hyperglycemia & infusion reaction ^creatinine increase & Acute kidney injury; §Infusion reaction Few AEs leading to treatment discontinuation No clinically meaningful on-target toxicity observed over background Differentiated profile due to avoiding on-target off-tumor toxicity BioAtla| Overview 20

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