Guardant Health's Duplex Sequencing Patent Challenge Rejected by Appeal Board

04:47 PM EDT, 10/15/2026 (MT Newswires) -- Guardant Health's (GH) challenge to all 30 claims of a US patent underlying duplex sequencing and owned by the University of Washington was rejected by the Patent Trial and Appeal Board, TwinStrand Biosciences, the patent's exclusive licensee, said Thursday. The board determined Guardant "failed to establish the unpatentability" of any of the challenged claims, TwinStrand said in a statement. The patent is one of two at issue in infringement litigation TwinStrand brought against Guardant in the US District Court for the District of Delaware, according to the statement. The ruling preserved a November 2023 jury verdict that Guardant "willfully infringed" the patent and awarded more than $245.2 million in damages, accrued royalties and interest through May 2026, TwinStrand said. Guardant was also directed to pay an ongoing royalty of 6% on all covered products and services through March 2033, TwinStrand said. Guardant did not immediately respond to a request for comment from MT Newswires.