Arizona Tribune - AbTherx and Mosaic Biosciences Forge Exclusive Partnership to Provide Milestone and Royalty-Free Access to AbTherx's Premier Human Antibody Discovery Technology

• Mosaic becomes the exclusive provider of antibody discovery services using AbTherx's Atlas™ Full Human Diversity Mouse

• Streamlined milestone- and royalty-free access with flexible engagement options

• End-to-end program integration from in vivodiscovery through candidate selection, creating a single, premium path to the clinic

MOUNTAIN VIEW, CA AND BOULDER CO / ACCESS Newswire / September 17, 2025 / AbTherx and Mosaic Biosciences today announced a strategic agreement under which Mosaic will be the exclusive provider of antibody discovery services using AbTherx's Atlas Full Human Diversity (FHD) Transgenic Mouse. The collaboration establishes a unified pathway for biotech and biopharma partners to launch discovery campaigns powered by the FHD platform, with Mosaic providing a seamless, end-to-end experience from immunization through candidate nomination. The partnership also introduces a milestone- and royalty-free access model, providing greater flexibility and operational efficiency for teams advancing new therapeutics.

This collaboration brings together industry-leading platforms in a fully integrated discovery program, offering drug developers two complementary routes to antibody generation. Partners can now pair in vivo discovery using AbTherx's advanced FHD transgenic platform with Mosaic's in vitro engine-including phage and yeast display for de novo discovery and rapid lead optimization-plus engineering, functional assays, and developability. The result is broader epitope coverage, greater sequence diversity, and higher-quality therapeutic candidates, all supported by continuous data flow and fewer vendor touchpoints.

"This is about giving innovators a more streamlined path to high-quality therapeutic candidates," said Eric Furfine, PhD, CESO, Mosaic Biosciences. "With exclusive access to the Full Human Diversity mouse paired with Mosaic's downstream engineering, functional assays, and developability capabilities, our partners benefit from a single integrated path from design and immunization through candidate nomination. We're combining discovery breadth with operational clarity-and our milestone- and royalty-free option helps make budgets more predictable."

"AbTherx has become the market leader in developing innovative human transgenic technologies for therapeutic antibody discovery," said Justin Mika, CEO, AbTherx. "By granting Mosaic exclusive service rights to our Full Human Diversity platform, we're enabling drug developers to engage a quality-driven, ex-pharma team and benefit from a consistent, efficient experience from discovery through selection. The combination of in vivo and in vitroapproaches maximizes sequence and epitope diversity, improves reliability and speed, and ultimately increases the likelihood of program success."

The Atlas Full Human Diversity Mouse is engineered to capture a broad, human-like antibody repertoire by sourcing VH and VK alleles that represent >99% of expressed human sequences and boost productive B-cell rearrangement to deliver human-like diversity by using functional VH and VK components only and excluding pseudogenes and other non-productive alleles. The transgenes were carefully curated to avoid patented alleles and rare/ethnic variants that could elevate immunogenicity or IP risk, creating a next-generation platform that improves upon the functional and freedom-to-operate limitations of other models.

Through this partnership, AbTherx and Mosaic will coordinate scientific support and technology transfer to ensure consistent, high-quality execution across the discovery workflow.

About AbTherx

AbTherx is advancing medicine with revolutionary technologies that accelerate and enable therapeutic antibody discovery. Through an exclusive license from Gilead Sciences, AbTherx has released Atlas™ Mice, a suite of novel transgenic technologies designed for unmatched performance and Freedom to Operate. For over 20 years, a core group of AbTherx's scientists have worked together to push the boundaries of antibody discovery technologies, resulting in more than 1,000 successful discovery campaigns and the development of 13 marketed therapeutics. AbTherx's industry-leading team creates transformative solutions to overcome the most demanding challenges in delivering innovative medicines. Committed to making its technologies accessible to all, AbTherx offers flexible partnering models that meet the needs of drug developers of all sizes. For more information, please visit www.abtherx.com.

About Mosaic Biosciences

Mosaic Biosciences is pioneering a transformative model for drug discovery, offering biotech, biopharma, and academic institutions a fully integrated platform for therapeutic discovery, characterization, and optimization, specializing in protein therapeutics. Mosaic's approach seamlessly incorporates essential screening, such as developability assessment and advanced cell-based assays, into the discovery process, ensuring that potential therapeutics are evaluated for their practical application from the outset. Mosaic's partners also benefit from rapid evaluations of animal pharmacokinetic and pharmacodynamic studies, allowing for swift decision-making. With access to cutting-edge proprietary tools and data-driven methodologies, Mosaic's nimble, multidisciplinary team of experienced scientists collaborates closely with partners to deliver innovative solutions to modern drug discovery. United by a shared commitment to advancing human health, Mosaic empowers partners to achieve therapeutic breakthroughs efficiently and effectively. For more information, please visit www.mosaicbio.com.

AbTherx Media Contact

Stacey Borders
[email protected]

Mosaic Biosciences Media Contact

Chrissy Conti
[email protected]

SOURCE: AbTherx, Inc

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