Isomorphic Labs closed $2.1 billion in Series B funding, the second largest biotech fundraise on record. Thrive Capital led the round, with Alphabet, Temasek, Capital G and the UK Sovereign AI Fund participating. The only bigger haul in biotech history is Altos Labs’ $3 billion emergence in 2022, another AI-focused drug discovery engine.
What did $2.1 billion actually buy? A platform with no disclosed pipeline molecules. Isomorphic says the Series B goes toward “continued development and deployment” of its AI drug design engine, built on AlphaFold models that won chemistry’s Nobel Prize in 2024. The company is building an internal candidate pipeline in oncology and immunology, but nothing has reached the clinic.
For a read on what the platform can command: Eli Lilly paid $45 million upfront in January 2024 with $1.7 billion in contingent milestones; Novartis fronted $37.5 million against $1.2 billion in contingent payments. Both deals remain early. Meanwhile, PitchBook clocked $33.8 billion in biopharma VC in 2025, most of it flowing to later-stage assets. Isomorphic cut the other direction entirely.
PitchBook analyst Ben Zercher suggests Isomorphic appears to be operating outside the normal funding logic, given its Google DeepMind halo. “Rounds like these give tech capital a place to go in biotech, while the rest of the industry stays focused on getting drugs to patients,” he told BioSpace.
Isomorphic’s prior external round, $600 million, closed in March 2025. This Series B more than triples that in under a year. Whether an AI platform that’s never put a drug in the clinic can justify the price is the question Thrive apparently chose to fund.
— Diana Kowalski