Menlo Park-based biotechnology company Hexagon Bio has raised $62 million in Series C financing to advance a new cancer treatment into clinical development and expand its discovery platform for antibody-drug conjugates.
The round was led by The Column Group, with participation from Nextech Invest, Deviation Capital, 8VC and Canada Pension Plan Investment Board.
Founded by scientists including Maureen Hillenmeyer, Colin Harvey, Brian Naughton and Yi Tang, Hexagon is using genomics and computational biology to discover therapeutic molecules produced by microorganisms.
Hillenmeyer, the company's CEO, previously directed natural product discovery research at Stanford's Genome Technology Center. Naughton previously worked on human genetics and served as a founding scientist at 23andMe.
The company is focusing on antibody-drug conjugates, or ADCs, a class of cancer medicines designed to deliver potent therapeutic compounds directly to cells expressing specific biological targets.
An ADC combines an antibody, which recognizes a target on a cancer cell, with a chemical payload intended to kill that cell.
This approach can deliver powerful drugs more selectively than conventional chemotherapy, but existing ADCs face limitations.
Many use payloads from a relatively small set of drug classes, particularly topoisomerase inhibitors and microtubule inhibitors.
Tumors can develop resistance to those mechanisms, while toxic effects can limit the doses patients receive.
Hexagon is attempting to discover payloads with different biological mechanisms.
Its technology analyzes microbial genomes to identify genetic pathways responsible for producing biologically active molecules.
Microorganisms have evolved a wide range of chemical compounds, many of which interact with fundamental cellular processes.
By combining genome sequencing, computational analysis and synthetic biology, Hexagon aims to identify compounds that could become useful components of new cancer medicines.
Its lead drug candidate, HEX-360, is an ADC targeting HER2, a protein associated with several cancers.
The drug incorporates a novel payload designed to inhibit protein translation, the process cells use to manufacture proteins.
This mechanism differs from the payloads commonly used in currently marketed ADCs and may offer a way to treat tumors resistant to existing drugs.
Hexagon presented preclinical findings at the American Association for Cancer Research annual meeting in 2026.
According to the company, HEX-360 demonstrated comparable or superior efficacy to a comparator modeled on Enhertu at matched payload exposure in certain laboratory and animal tumor models.
The company also reported durable responses in models resistant to topoisomerase inhibitors, along with encouraging tolerability findings in rats and non-human primates.
These are preclinical results. They do not establish that HEX-360 is safe or effective in human patients.
Hexagon expects to begin its first Phase 1 clinical study in the first half of 2027.
The new financing will support that study and the development of additional ADC candidates, including therapies combining more than one payload.
The broader opportunity is significant because ADCs have become an important area of oncology drug development.
Pharmaceutical companies are investing in ways to improve tumor targeting, drug delivery, treatment durability and the range of cancers that can be addressed.
Hexagon's differentiation lies primarily in its discovery platform rather than the antibody component alone.
If it can repeatedly identify useful payload mechanisms from microbial genomes, the company could potentially generate multiple drug candidates or establish partnerships with larger pharmaceutical developers.
However, discovering a novel mechanism is only the beginning of drug development.
Payloads must demonstrate appropriate potency, stability, compatibility with antibody-linker chemistry and acceptable safety profiles.
Clinical trials will need to establish whether the preclinical benefits translate into improved patient outcomes.
Hexagon also faces competition from other ADC developers and biotechnology companies using computational methods to discover new therapeutic compounds.
The company's next milestone is the transition of HEX-360 into human testing.
The larger question is whether its genome-mining platform can produce a repeatable pipeline of differentiated medicines, rather than a limited number of promising preclinical molecules.