BioAtla Investor Presentation Deck

FDA cleared IND for Phase 1/2 trial design in advanced adenocarcinoma Group A Accelerated Titration Convert to standard titration when any grade 22 AE (except AE due to the underlying disease or an extraneous cause) or a DLT bicatla DL8A: 125 µg/kg DL7A: 40 µg/kg DL6A: 12.5 µg/kg ↑ DL5A: 4 µg/kg DL4A: 1.25 µg/kg DL3A: 0.4 µg/kg DL2A: 0.125 µg/kg DL1A: 0.04 µg/kg CAB-EpCAMXCAB-CD3 bispecific TCE (BA3182) • Group B Standard Titration Dose escalation using the Bayesian Optimal Interval (BOIN) design Grade 22 AE or DLT MTD or PAD DL4B DL3B ↑ DL2B ↑ DL1B: highest dose tested in Group A Group C Standard Titration with Priming If one Grade > 2 CRS is observed, initiate priming dose evaluation Grade >2 CRS Priming Dose D1 PDLXC PDL2C PDL1C 1 ↑ CIDI MTD/PAD DL2C DL1C DL1A: MABEL based starting dose 0.04 µg/kg The actual number of dose levels (cohorts) in Accelerated Titration will depend on the dose level at which the first Grade 22 AE or DLT occurs MTD: Maximum tolerated dose; PAD: Pharmacologically active dose Dosing schedule: every week (QW) initially, every two weeks (Q2W) may also be explored PDL 1C: first priming dose level; PDLxC: final priming dose level Part 1: Up to 128 patients with advanced adenocarcinoma ● ● Up to 8 patients in the accelerated titration Up to 60 in each of the 2-treatment schedules for 10 planned standard titration dose levels Part 2: Open-label study to evaluate the efficacy and safety of BA3182 in patients with advanced adenocarcinoma who have a qualifying EpCAM- expressing tumor membrane percent score (TmPS) (to be determined based on Part 1 data). BioAtla| Overview 39

View entire presentation