Harbour Antibodies BV v. Teneobio/Amgen — Jury Awards $20.2 Million in Willful Heavy-Chain Antibody Patent Infringement

Background

Heavy chain-only antibodies (HCAbs) are a class of therapeutic molecules that lack the light chain normally found in conventional antibodies. First discovered in camelids (camels, llamas) and sharks, these single-domain antibodies are prized for their small size, stability, and ability to access epitopes that conventional antibodies cannot reach. Generating HCAbs in transgenic mice — rather than camelids — with fully human variable regions is a commercially valuable capability, because it allows pharmaceutical companies to use established mouse immunization platforms to produce next-generation antibody therapeutics.

The patent at issue — U.S. Patent No. 10,906,970, assigned to Harbour Antibodies BV and originally developed at Erasmus University Medical Center Rotterdam — covers precisely this technology: methods for producing HCAbs in transgenic mammals engineered with modified immunoglobulin heavy chain loci that lack the CH1 exon. Without CH1, the heavy chains fold and function independently without requiring a light chain partner. The patent traces back to foundational research by inventors including Dr. Roger Kingdon Craig.

Teneobio, Inc. was a South San Francisco biotechnology company founded around 2015 to develop its own UniAb™ heavy-chain-only antibody platform. Amgen acquired Teneobio in late 2021 for approximately $900 million upfront, plus milestone payments, primarily to gain access to the UniAb platform and Teneobio’s pipeline of bispecific T-cell engagers. Shortly after the acquisition was announced, Harbour Antibodies and its co-plaintiffs filed suit in December 2021, alleging that Teneobio’s transgenic mouse platform for generating UniAb antibodies infringed the Erasmus/Harbour patent. Amgen, as Teneobio’s acquirer, was named as a co-defendant.

The Court’s Holding

The jury returned its verdict on June 12, 2026, finding that Amgen and Teneobio willfully infringed U.S. Patent No. 10,906,970 and awarding the plaintiffs $20.2 million in damages — the full amount requested. The willfulness finding is significant: under 35 U.S.C. § 284, a court may enhance damages by up to three times the jury’s award for willful infringement. Whether Judge Noreika will exercise that discretion remains for post-trial proceedings.

The verdict follows years of litigation including claim construction proceedings and a pre-trial ruling that excluded certain claims characterized as relating to “rodent antibody IP” from reaching the jury, narrowing the issues at trial. The specific claims of the ‘970 patent found infringed were the method claims covering the transgenic production process for heavy-chain-only antibodies — the core of what Teneobio’s UniAb platform does.

Key Takeaways

• A jury found willful infringement, opening the door to treble damages in post-trial proceedings — potential exposure could exceed $60 million if the court maximizes the enhancement.
• Amgen’s $900 million acquisition of Teneobio now carries this liability. Companies conducting IP due diligence on biotech acquisitions should note that foundational platform patents from academic institutions (here, Erasmus University) can create unexpected downstream risk.
• The verdict is not the end: post-trial motions (JMOL, new trial) and potential treble damages briefing will follow, as well as a likely appeal to the Federal Circuit.
• Heavy chain-only antibody technology is increasingly important in drug development (bispecifics, T-cell engagers, nanobodies). This ruling signals that key method patents in this space remain viable enforcement tools even against well-resourced defendants.

Why It Matters

This verdict arrives at a pivotal moment for antibody engineering. Heavy-chain-only antibodies — once an academic curiosity observed in camelids — have become a significant commercial platform for developing bispecific antibodies and other next-generation biologics. The $20.2 million willful infringement award against Amgen validates the commercial importance of foundational HCAb technology patents and demonstrates that even major pharmaceutical acquirers are not insulated from IP liability when they buy companies built on platforms that may have infringed earlier academic patents.

For the biotech industry, the case is a reminder that transgenic animal platforms — the infrastructure for generating therapeutic antibody candidates — carry their own patent landscapes that must be cleared before commercialization. Universities and academic research institutions also take note: Erasmus University’s co-inventor role and Harbour Antibodies’ enforcement effort show that academic IP in foundational biology can be commercially enforced against large corporate defendants decades after the underlying research.