PTO Issues Guidelines: Admitted Prior Art Cannot Be the Basis of an IPR Challenge
Under 35 U.S.C. § 311(b), IPRs are only instituted “on the basis of” patents and printed publications. But, occasionally petitioners have relied on statements in a patent’s specification as “applicant admitted prior art” and included that prior art in their grounds in a petition—either alone or in combination with other references.
On August 18, 2020, the PTO issued guidelines on how Board panels should treat applicant admitted prior art, determining that it does not qualify as “prior art consisting of patents or printed publications,” but falls into the category of evidence that the Board may consider for more limited purposes.
In the reexamination context, the PTO has not allowed applicant admitted prior art to be the basis of a reexamination, but has permitted its use in combination with other prior art patents and printed publications. Consistent with this, the majority of Board IPR panels have determined that applicant admissions in the specification of a challenged patent are not prior art patents that can form the basis for an IPR alone. But, some panels have instituted trial based on applicant admitted prior art alone. And, other panels have allowed its use in combination with other prior art patents and printed publications. The PTO guidelines were issued to resolve this confusion.
The PTO concluded that a patent cannot be prior art to itself, and thus the patent challenged in the IPR cannot be a prior art patent upon which an IPR can be based. Thus, applicant admitted prior art cannot be used alone as the basis for an IPR. But, statements in a patent’s specification can be used as evidence of the general knowledge of someone of ordinary skill in the art, which is fundamental to a proper obviousness analysis. As examples, the general knowledge of those skilled in the art can be used to supply missing claim limitations that were generally known but missing from the prior art, supply a motivation to combine references, or demonstrate the knowledge of those skilled in the art at the time of the invention.
The guidelines provide helpful clarity for patent challengers to use in drafting grounds in petitions.