TwinStrand and the University of Washington Win a $245.2 Million Final Judgment Against Guardant Health, Which Says It Will Appeal

How $83.4 million became $245.2 million

The jury that heard the case in November 2023 awarded $83.4 million for infringement through June 30, 2023, applying a 6% royalty to revenue from the accused products. According to TwinStrand's release, that revenue came to roughly 90% of Guardant's total during the infringement period. The final judgment leaves that award standing and adds $19.5 million in supplemental damages for sales between July 1, 2023 and February 5, 2024, $119.4 million in accrued royalties at the same 6% rate through May 31, 2026, and $22.9 million in interest, which keeps running on the unpaid balance.

The two patents cover duplex sequencing, in which both complementary strands of each DNA molecule are sequenced independently and compared so that a true variant must appear on both. TwinStrand puts the resulting accuracy gain at more than 10,000-fold over conventional next-generation sequencing, which is what allows ultra-low-frequency variants to be separated from sequencing error. The 11 products the judgment lists span Guardant's therapy-selection, recurrence-monitoring and screening lines.

Validity was contested down to the wording of the judgment

Guardant had asked the court to enter no judgment on validity at all. The court instead adopted TwinStrand's proposed language and entered judgment upholding the validity of the asserted claims of both patents. It had already denied Guardant's bid to overturn the verdict or obtain a new trial, and every Guardant counterclaim was dismissed or withdrawn before trial.

"Duplex Sequencing solved an accuracy problem the sequencing field had worked on for years, and this judgment affirms the jury's finding that Guardant Health built products on that invention without a license," said Chad Waite, chair of the TwinStrand board of directors. On validity, Waite added: "We have been confident in these patents since the day they issued."

Both companies acknowledge that proceedings over the same patents continue at the U.S. Patent and Trademark Office. TwinStrand says neither patent has been invalidated. Guardant says both "have been preliminarily invalidated" in its ongoing challenges there, and that it is separately pursuing appeals before the U.S. Court of Appeals for the Federal Circuit. The district court's judgment does not resolve those proceedings.

Guardant says the order reaches 2023 versions, not today's tests

"We strongly disagree with this decision and will promptly be appealing for its overturn," said John Saia, Guardant Health's chief legal officer. "We have full faith in the strengths and merits of Guardant's intellectual property and R&D and are confident we will ultimately prevail on appeal."

The substantive part of Guardant's statement concerns scope. The company says the royalty order "expressly defined the products included as those that existed at the time of the trial in 2023, many of which have been discontinued or significantly upgraded." On that reading, Guardant says the current versions of Guardant Reveal and Shield are excluded from the order and from potential royalties, and it says it has validated design improvements to Guardant360 and related services that would remove the ongoing royalty from those products as well. Neither release describes the design changes or says whether the court has ruled on them. Execution and collection are stayed pending the appeal.

Why This Matters to the APO|APE Reader

Shield entered the judgment as "Guardant LUNAR-2 / Shield," the research-stage name it carried in 2023, before FDA approval and before UnitedHealth Group added it to coverage, which is the gap Guardant's "existed at the time of the trial" argument is built to exploit. Whether a redesigned assay still practices a duplex sequencing claim is a question for the Federal Circuit or for a later contempt or accounting proceeding, and the quarterly sales report the court ordered is the mechanism by which TwinStrand will test it. For a laboratory that reports a Guardant360 CDx result, nothing changes today, since the judgment awards money and a royalty and enjoins no test. Every ctDNA assay that relies on strand-matched error correction, from any vendor, now has a district court judgment saying that method belongs to the University of Washington.