Addressing the burden-shifting requirements for establishing priority of prior art references, the Patent Trial and Appeal Board (PTAB) recently issued two decisions finding that the petitioners failed to meet their burden to establish that a prior art reference was entitled to its earlier-claimed priority date. VMware, Inc. v. Clouding Corp., Case Nos. IPR2014-01304; -01305 (PTAB, Jan. 7, 2015) (Chang, APJ); Ariosa Diagnostics, Inc. v. Illumina, Inc., Case No. IPR2014-01093 (PTAB, Jan. 7, 2015) (Green, APJ).

In 2015, the Federal Circuit upheld a Board determination in an inter partes review (IPR) proceeding that the petitioner had the burden to prove that a prior art patent was entitled to its earlier-claimed priority date. There, the U.S. Court of Appeals for the Federal Circuit explained how the burden would shift back and forth between petitioner and patent owner with respect to proving priority, but that the ultimate burden of persuasion always remained with the petitioner. The Ariosa andVMware decisions, discussed below, mark the first time that the Board has applied the standard set out by the Federal Circuit in Dynamic Drinkware.

In Ariosa, the patent owner attempted to rely on an application filed after the effective filing date of the patent-at issue, but which claimed priority from an earlier-filed provisional application. The Board faulted the petitioner for failing to explain how the application met the requirements for prior art under §102(e), noting that the petitioner only included a general allegation that the application was prior art under “102 (a), (b), and/or (e).” According to the Board, without explicitly stating how the application qualified as prior art under §102(e), the patent owner was never put on notice of the petitioner’s contentions. As a result, the Board determined that burden never shifted to the patent owner to disprove the priority date, and therefore the petitioner failed to meet its burden to establish the reference as prior art.

In VMware, the petitioner relied on §102(e) to qualify a reference patent as prior art. In this case, the reference patent claimed priority from a non-provisional continuation-in-part and a separate provisional application. The petitioner explained how the priority documents provided written description support for the disclosures in the reference patent and how those priority documents disclosed the subject matter of the patent-at-issue. The Board found this insufficient, however, because the petitioner did not explain how the priority documents provide written description support for the claims of the reference patent, and thus did not meet its burden to establish that the reference patent is entitled to its priority date.

Practice Note: Petitioners at the PTAB are advised to explicitly state in the Petition the basis relied on as to why a reference qualifies as prior art.