FairJourney Bio brings transgenic mouse antibody discovery in-house through AbTherx partnership
FairJourney Bio (FJBio) has entered a partnership with AbTherx, Inc. to integrate transgenic mouse-based antibody discovery into its existing discovery and engineering workflow. The agreement, announced at the BIO International Convention 2026, gives FJBio access to AbTherx’s Atlas™ Full Human Diversity (FHD) and Common Light Chain (cLC) mouse technologies.
A single continuous workflow
The partnership allows partner programmes to progress from immunisation through single B-cell screening, optimisation, candidate stability assessment and cell-line development without transferring between external providers. This work will be run by one team across FJBio’s three sites: Porto, Portugal; Cambridge, UK; and San Diego, USA. The intention is to reduce the number of handovers a programme undergoes and to produce candidates designed for downstream development rather than selected solely on binding activity.
The Atlas™ mice originate from the team responsible for HuMAb Mouse®, a platform whose technology underpins 13 marketed antibody therapeutics. Within FJBio, the Atlas mice will feed directly into the company’s B-Cell Navigator platform, its single B-cell screening and developability engine, with the aim of incorporating developability considerations from the initial sequence stage.
Technology characteristics
According to the companies, AbTherx’s patent-pending FHD mice are engineered to produce fully human antibodies, sourcing VH and VK alleles said to represent more than 99% of the expressed human repertoire. The cLC mice are designed to support native-structure bispecific and multispecific IgG formats intended to aid manufacturability. The companies report that the Atlas platform has been assessed in multiple independent, head-to-head studies against legacy platforms, with differences noted in V gene usage, hit rates, antibody diversity and binding profiles, epitope coverage, and hybridoma and B-cell stability.
Dr Werner Lanthaler, Chief Executive Officer of FairJourney Bio, commented: “We are investing so a partner’s programme can run from immunisation to a developability-assessed lead inside FJBio, without changing hands. Following a molecule under ‘one roof’ and with one team of scientists increases probabilities of success significantly.”
Dan Rohrer, Chief Technology Officer at AbTherx, noted that AbTherx has spent decades building and refining its technologies, adding that “even the most sophisticated platform requires knowledge and diligence to reach its full potential.”
US expansion continues
The announcement follows FJBio’s continued build-out of its San Diego site, which now includes a dedicated in-house cryo-EM facility supporting structure-guided antibody design. Since Partners Group’s 2024 investment, which supported the company’s US expansion, FJBio has expanded its structural biology capabilities alongside its existing discovery headquarters in Porto and engineering centre in Cambridge.
FJBio says it has completed more than 1,400 programmes for over 250 partners across pharma, biotech and academia, with 20 partner assets currently in clinical trials.
Dr Werner Lanthaler, Chief Executive Officer of FairJourney Bio
