On June 27, 2017, the U.S. Federal Circuit vacated and remanded the Patent Trial and Appeal Board’s (Board) decisions in three interference proceedings between the Board of Trustees of Leland Stanford Junior University (Stanford) and the Chinese University of Hong Kong (CUHK) (Case No. 2015-2011).

Competing inventors at Stanford and CUHK developed methods for diagnosing aneuploidies—conditions characterized by an abnormal number of chromosomes (e.g., Down’s Syndrome and Turner’s Syndrome)—using maternal blood samples. Maternal blood contains very small amounts of fetal DNA, and maternal blood sampling is far less invasive than previous methods of sampling fetal DNA. Competing inventors developed techniques for detecting the fetal DNA in maternal blood.

A Stanford application was filed in 2007 with claims to analyzing certain “target sequences” of fetal DNA. A CUHK application, published in 2009, described a “random sequencing” method. This method uses a massively parallel sequencing (MPS) technique that does not require use of “target sequences.” After the CUHK application published, Stanford cancelled its original claims and replaced them with claims to sampling “randomly selected” DNA fragments using MPS. The 2007 Stanford application had disclosed that “the Illumina [DNA] sequencing platform” could be used to perform MPS.

Both Stanford and CUHK requested interferences before the Board to determine who invented the random sequencing method. CUHK claimed that, in 2011, Stanford saw CUHK’s claims to random MPS, and changed its application to claim that technique. CUHK moved to have Stanford’s claims held unpatentable for lack of written description support for random MPS. The Board found that Stanford’s specification disclosed “targeted” rather than “random” MPS, and would not have indicated to one of ordinary skill in the art that the inventor was in possession of the claimed random MPS method. It held Stanford’s claims unpatentable for lack of written description.

The Federal Circuit, inter alia, vacated the Board’s decision, stating that the Board erred in analyzing written description, and remanded the case. The Circuit first found the Board erred by relying on CUHK’s expert testimony and several publications discussing a DNA sequencing platform that differed from the Illumina platform. The Circuit further stated that the Board erred because “the Board’s task was to determine whether the [Stanford specification’s] written description discloses random MPS,” “not whether the description does not preclude targeted MPS.” Finally, the Circuit stated that the Board failed to compare specific sentences and phrases referencing the sequencing process of the Stanford specification to the Stanford claims, e.g., the specification phrase “using the attachment of randomly fragmented genomic DNA.”

On remand, the Circuit instructed the Board to examine whether a person of ordinary skill in the art would have understood that the Stanford specification disclosed random MPS sequencing, as opposed to whether the specification did not preclude targeted MPS sequencing. Specifically, it instructed the Board to determine whether a person of ordinary skill would have known, as of the Stanford priority date, that the reference to Illumina products meant random MPS sequencing as recited in the claims, by examining pre-filing date factual record evidence.