BioAtla Investor Presentation Deck

Promising safety and tolerability profile continues to emerge 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 Constipation Peripheral Neuropathy BA3011 (N=18) 17 (94%) 5 (28%) 2 (11%)* Diarrhea 0 2 (11%) BA3011 + Opdivo (N=9) 9 (100%) 2 (22%) 3 (33%)^ All Grade 1-2 (11%) All Grade 1-2 (15%) All Grade 1-2 (15%) No grade 3 - 4 AEs related to constipation, peripheral neuropathy or diarrhea observed. Low-grade constipation observed is consistent with baseline levels seen in advanced cancer patients. 0 0 ■ ■ ■ ■ No treatment-related deaths Few treatment-related SAEs 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 Interim data- Data cut-off of Dec 21, 2022 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) bicatla reporting. A grading (severity) scale is provided for each AE term. 2As assessed by the investigator. Missing responses are counted as related. "DKA & infusion reaction "creatinine increase, diplopia unrelated to BA3011 post data transfer) & acute kidney injury; § DKA & infusion reaction BioAtla| Overview 21

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