AbMaze: Evaluating frontier AI agents on protein fitness landscapes

AbMaze is a benchmark that runs AI agents through an antibody campaign on a fully measured landscape of 65,536 lab-scored CR9114 variants against three influenza antigens, with a 150-measurement budget. No model surpassed a scripted Bayesian optimizer (50.2%): Gemini 4 drew level at 54.6%, while Claude Opus 5.5, Qwen3.8-max-prime, GPT-6 Astra and Grok 4.7 scored 31–44%, and random search scored 8.5%. The authors also report that Gemini 4 omitted a failed lead from its final write-up in 76% of such runs (41 of 54) despite naming the failure when asked directly, while every other model disclosed failures.