Third Rock signs AI antibody deal worth up to $2.16bn with Beijing start-up Funnel

Third Rock Ventures has signed a partnership with Funnel Biosciences, a Beijing AI antibody start-up founded in February 2026, under which Funnel can earn total potential fees of up to $2.16 billion for designing biologic drug candidates against targets the venture firm chooses¹. The deal was reported on 10 November¹.

The terms

Funnel, known in China as Fangnuo Biotech, will apply its epitope-guided AI antibody discovery platform to discover and develop candidates, including antibody-based drugs, against multiple targets nominated by Third Rock¹. Funnel receives a platform access fee whose size was not disclosed, on top of eligibility for the $2.16 billion in potential fees¹. No split between near-term payments and later milestones was given.

The platform pairs generative algorithms with physics-based energy functions to design biologics from scratch¹. Funnel's pitch is that the conventional route, animal immunisation and phage display followed by repeated screening and optimisation, struggles with structurally complex targets such as multi-pass membrane proteins¹. The company says its approach produces candidates with "picomolar affinities, favourable developability, and low immunogenicity"¹.

Funnel was co-founded by Dr Liu Jintan, a biotech executive and cancer researcher who previously worked at MSD in the US, and Dr Mingchen Chen, a computational biophysicist who researches AI protein design¹. In a joint statement the founders said "TRV's experience in scientific translation, drug development and company creation complements Funnel's capabilities"¹.

What it means for the market

The structure is the notable part. Third Rock has generally worked as an incubator of biotech start-ups rather than taking a direct role in drug discovery¹. Here it is acting more like a pharma partner, buying platform access and nominating targets. This is its second publicly disclosed deal of the kind, after a peptide therapeutics programme with Perpetual Medicine, a Shanghai computational physics and AI company¹. That alliance delivered its first development candidate in June, less than 18 months after signing¹.

For investors and corporate development teams, two patterns stand out. A venture firm is now sourcing AI-designed molecules from Chinese platform companies directly, a route that could feed its own company creation without waiting for a pharma licensee. And a company only months old has secured a headline value in the billions on the strength of its design platform, before any disclosed candidate¹. For other AI antibody design vendors, the deal adds a new kind of buyer to the usual list of pharma companies.

Caveats

The $2.16 billion is a ceiling on potential fees, not committed money, and the upfront fee was not disclosed¹. Funnel's performance claims for its platform come from the company and are not backed by published data in the report¹. The number of targets, the therapeutic areas and the timeline were not given. The nearest precedent, the Perpetual Medicine alliance, took less than 18 months to reach a first development candidate¹.