Inter Parte Reviews (IPRs) can be instituted "only on a ground that could be raised under section 102 or 103 and only on the basis of prior art consisting of patents or printed publications.”  35 U.S.C § 311 (b).  A recurring issue, however, is the effect of statements made by the patentee in the specification of the challenged patent. Such statements / admissions are sometimes referred to as “applicant admitted prior art.”  Some Board decisions have permitted reliance on such admissions, whereas others have not.

On August 18, 2020 the Director of the USPTO issued a Memorandum setting forth the USPTO's interpretation of 35 U.S.C. § 311 (b) with respect to “applicant admitted prior art”, as well and “binding guidance” that “shall be followed by all members of the Patent Trial and Appeal Board ("Board") facing this issue.”

The Memorandum provides, consistent with reexamination practice, that such statements alone cannot “qualify as ‘prior art consisting of patents or printed publications,' but fall into the category of evidence the Board may consider for more limited purposes.”  The Memorandum provides clear guidance with well-explained examples of permissible uses of such statements, concluding:

“In summary, the basis of an IPR must be one or more prior art patents or printed publications. Statements in the specification of the patent being challenged are not prior art patents or printed publications, and thus cannot form the basis of an IPR.  Nevertheless, the Board can also rely on the general knowledge of a person with ordinary skill in the art in assessing the patentability of the patent claims at issue. Statements made in the specification of the patent that is being challenged in an IPR can be used as evidence of such general knowledge, and thus, provided the basis of the IPR is one or more prior art patents or printed publications, can be used to (1) supply missing claim limitations that were generally known in the art prior to the invention (for pre-AIA patents) or the effective filing date of the claimed invention (for post-AIA patents); (2) support a motivation to combine particular disclosures; or (3) demonstrate the knowledge of the ordinarily-skilled artisan at the time of the invention (for pre-AIA patents) or the effective filing date of the claimed invention (for post-AIA patents) for any other purpose related to patentability.”