Isomorphic Labs closed a $2.1 billion Series B to scale its AI-driven small-molecule drug design engine, IsoDDE. The funding makes the round one of the largest ever for a biotech startup and supports continued model development, pipeline advancement toward the clinic, and additional hiring across AI, engineering, drug design and clinical development. The company emphasized that IsoDDE is built as a unified drug design and development engine rather than software to be licensed. Isomorphic said its internal pipeline is concentrated on oncology and immunology while maintaining partnerships with Novartis, Eli Lilly and Johnson & Johnson. Investors are effectively underwriting a shift toward end-to-end AI-enabled discovery and clinical execution, even as the company remains comparatively light on public program specifics.