Federal Circuit Rejects PTAB's 'Ministerial' Requirement for Prior Art Priority

The U.S. Court of Appeals for the Federal Circuit has rejected the Patent Trial and Appeal Board's reliance on a ministerial-requirements-only test for determining when a patent cited as prior art is entitled to the filing date of an earlier application in its priority chain, Reuters reported on October 13, 2026. The ruling addresses a recurring question in inter partes review and examination practice: how much proof is required before a reference patent can be backdated to an earlier U.S. filing for prior art purposes.

According to the report, the Board had applied a two-part approach under which a reference patent needed only to satisfy the ministerial requirements of AIA Sections 119 and 120 - principally a proper benefit claim, such as a specific reference to the earlier application filed in the required manner and time - in order to be treated as prior art as of the earlier filing date. The Federal Circuit held that satisfying those formal requirements alone does not establish the reference's entitlement to the earlier date.

The decision is consistent with the court's line of cases beginning with Dynamic Drinkware v. National Graphics (2015), which requires a showing that the earlier application provides Section 112 support for the relied-upon subject matter, and with the court's precedential August 2026 decision in Dental Monitoring SAS v. Align Technology (No. 25-1752), which held that the Dynamic Drinkware principle applies to AIA patents: a challenger should not be able to backdate prior art through an earlier application that would not have supported a patent on the claimed subject matter.

The practical consequences run in both directions. Petitioners and examiners relying on a reference's claimed priority date must be prepared to show adequate support in the earlier application, not merely a facially proper benefit claim; patent owners, in turn, retain a meaningful route to challenge the backdating of references that intervened only after the actual filing date of the reference. The ruling adds certainty to what counts as prior art in PTAB proceedings, where priority-chain attacks have become a standard feature of both petitions and patent owner responses.

Original Link: https://www.hoyngrokhmonegier.com/news-insights/detail/upc-unfiltered-by-willem-hoyng-upc-decisions-week-41-2026