BioAtla Investor Presentation Deck

Liposarcoma and Synovial sarcoma: Phase 2 Progression Free Survival Progress-Free Survival Probability 1.0- 0.8- 0.6 0.4 0.2 - 0.0- Number at Risk All Patients 6 ■ 0 bicatla T 1 5 Liposarcoma BA3011 1.8mg/kg Q2W n=6 Events n(%) TmPS>=70 4 (66.7) 2 4 3 3 4 Median (mos) (95% CI) 4.6 (0.2 - NE) Months from First Dose 3 Interim data- Data cut-off of Oct 17, 2022 5 1 6 1 PFS 3mo % (95% CI) 66.7 (19.5, 90.4) 7 0 8 Progress-Free Survival Probability Number at Risk BA3011 1.0 0.8 0.6 0.4- 0.2- 0.0 0 5 1 4 Synovial Sarcoma BA3011 1.8mg/kg Q2W n=5 Events n(%) TmPS>=70 4(80.0) 2 3 Median (mos) (95% CI) 4.4 (1.1- NE) 3 Months from First Dose 1 4 1 5 0 PFS 3mo % (95% CI) 53.3 (6.8, 86.3) 6 Interim results satisfied the pre-defined Go criteria of liposarcoma and synovial sarcoma cohorts into part 2 of the Phase 2 study. BioAtla| Overview 40

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