IP Law Daily, PATENT—Fed. Cir.: Validity ruling on University of Washington’s DNA sequencing patent vacated on appeal, (Jan 26, 2026)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

PTAB erroneously required proof of motivation and expectation of success, even though prior art disclosed both steps in one embodiment.

In a non-precedential disposition, the U.S. Court of Appeals for the Federal Circuit vacated a final written decision of the Patent Trial and Appeal Board (PTAB) that had upheld the validity of all 30 claims of a DNA sequencing patent owned by the University of Washington. The panel held that the PTAB erred in requiring the petitioner in the inter partes review (IPR) proceedings to demonstrate a motivation to combine and a reasonable expectation of success for performing DNA amplification followed by sequencing, where those steps were already disclosed together in a single embodiment of a single prior art reference (Guardant Health, Inc. v. University Of Washington, No. 24-1129 (Fed. Cir. Jan. 23, 2026)).

Background. The appellant, Guardant Health, Inc., is a biotechnology company focused on noninvasive cancer diagnostics using advanced DNA sequencing methods. The appellee, the University of Washington, is a major public research university that conducts biomedical research through its academic and clinical programs.

The patent-in-suit, U.S. Patent No. 10,760,127 (the ’127 patent), claims methods of reducing sequencing errors through Duplex Consensus Sequencing (DCS). Claim 1 requires: (a) attaching barcoded adapters to double-stranded DNA to form asymmetrical molecules; (b) amplifying original strands of these molecules; (c) sequencing amplified strands to obtain paired reads; and (d) confirming read presence and comparing the data to a reference sequence to identify variants.

Guardant initiated inter partes review challenging claims 1–30 as obvious under pre-AIA 35 U.S.C. § 103 based on a combination of two related publications: U.S. Patent Application No. 2009/0298075 A1 (“Travers ’075”) and an article by the same authors published in Nucleic Acids Research in 2010 (“Travers 2010”). Guardant argued that paragraph 122 of Travers ’075 disclosed the sequence of DNA amplification by rolling-circle replication (RCR), followed by SMRT sequencing, using circular templates known as SMRTbells. The PTAB rejected the challenge, finding no persuasive motivation to combine the amplification and sequencing steps or a reasonable expectation of success in implementing both sequentially. Guardant appealed.

Motivation to combine. The Federal Circuit concluded that the PTAB erred by requiring a separate showing of motivation to combine when both the amplification and sequencing steps were disclosed together in the same embodiment in Travers ’075. Relying on General Electric Co. v. Raytheon Techs. Corp., 983 F.3d 1334, 1352 (Fed. Cir. 2020), the court held that “[w]hen the disputed elements of a claim are disclosed in a single embodiment in a single reference, no finding regarding a motivation to combine to arrive at those claimed elements is required.”

Because paragraph 122 of Travers ’075 expressly teaches RCR amplification of circular DNA followed by sequencing of the replicated product, Guardant was not required to prove an additional reason to link the two steps.

Petition theory. Although the PTAB treated Guardant’s petition as relying on a combination of multiple references, the Federal Circuit disagreed. It found that the primary theory advanced by Guardant cited paragraph 122 of Travers ’075 for both amplification and sequencing limitations. The court pointed out that while Travers 2010 was cited for sequencing context, the amplification step—and its temporal ordering before sequencing—came exclusively from a single embodiment in Travers ’075. Because Guardant’s challenge did not involve modifying Travers ’075 but relied on what it already disclosed, the Board’s analysis misconstrued the petition and improperly applied an additional burden.

Expectation of success. The Federal Circuit likewise found error in the Board’s demand for proof of a reasonable expectation of success in combining RCR and sequencing. Quoting Intelligent Bio-Sys., Inc. v. Illumina Cambridge Ltd., 821 F.3d 1359, 1367 (Fed. Cir. 2016), the court reiterated that expectation of success pertains to “the likelihood of success in combining references to meet the limitations of the claimed invention.” Since the key elements were found in a single embodiment of a single reference, there was no combination, and thus no need to demonstrate success in combining disparate teachings. The court distinguished In re Stepan Co., 868 F.3d 1342 (Fed. Cir. 2017), as inapplicable because that case dealt with combinations of multiple references or embodiments.

Enablement. As an alternative ground for affirmance, the University of Washington urged the court to find that the amplification-plus-sequencing disclosure in paragraph 122 of Travers ’075 was not enabled. The Federal Circuit declined to address that argument for the first time on appeal, noting that the PTAB had not reached the issue. Citing TriMed, Inc. v. Stryker Corp., 608 F.3d 1333, 1339 (Fed. Cir. 2010), the court remanded the case for the Board to assess enablement in the first instance.

Conclusion. Because the PTAB misapplied the obviousness framework by requiring a motivation to combine and a reasonable expectation of success where the prior art taught the claim limitations in a single embodiment, the Federal Circuit vacated the Board’s ruling and remanded. The panel left the costs to Guardant Health, the prevailing party on appeal.

The Case is No. 24-1129.

Judge: Stoll, K.

Attorneys: E. Joshua Rosenkranz (Orrick, Herrington & Sutcliffe LLP) for Guardant Health, Inc. William Milliken (Sterne Kessler Goldstein & Fox PLLC) for University of Washington.

Companies: Guardant Health, Inc.

Cases: Patent FedCirNews GCNNews