Ridge Bio raises $38M seed for AI-designed bioconjugate drugs
What's the deal? Ridge Biotechnologies has raised approximately $38 million in an upsized seed round to advance its AI-designed enzyme and linker platforms for precision therapeutics. Dimension CapitalDealroom has a profile for this one. Try Dealroom → anchored the round, joining founding investor Sutter Hill Ventures, which incubated the company, and Overlap HoldingsDealroom has a profile for this one. Try Dealroom →.
What's the endgame? The Palo Alto company uses machine learning models trained on high-throughput, cell-free experiments to design enzymes and targeted drug delivery systems. Its products attach payloads to proteins site-specifically and release therapeutic payloads only in target tissues, aiming at a longer-term goal of enzyme-based "Catalytic Medicines."
Why now? Ridge has added several partnerships over the past year, applying its NativeLink enzymes and ProTrigger linkers to biotechs' bioconjugate drug programs. The company says its approach generates up to a million-fold more sequence-function data than conventional methods.
Chief executive officer Weston Kightlinger said recent animal studies showed antibody-drug conjugates (ADCs) made with its enzyme had "several-fold lower toxicity than approved ADCs with improved efficacy," using the same antibody and payload amount.
By the numbers: At $38 million, the raise sits in the 99th percentile of all-time US seed rounds in health, out of nearly 11,000 comparable deals. The capital will fund partnerships, scale the data and machine learning platforms, broaden the enzyme and linker portfolio, and advance internal discovery programs.
What they're saying: Dimension Capital co-founder and managing partner Nan Li said Ridge "aims to enable new targets and mechanisms of action while delivering superior stability, biodistribution, and tissue selectivity to widen the therapeutic window." Ridge also picked up the 2026 SynBioBeta Rising Star Award.
The signal: Investor conviction at seed stage is concentrating in startups pairing machine learning with bioconjugate chemistry — a bet that computational design can safely reach drug targets conventional ADCs cannot.
Image credit: Generated with Gemini
