When challenging a patent in an inter partes review (“IPR”), petitioners are limited to arguing that the patent is anticipated or obvious based on existing patents and printed publications. According to 35 U.S.C. § 315(e)(1) and (2), a petitioner in an IPR that results in a final written decision (FWD) may not raise in the USPTO or a civil action or an ITC proceeding “any ground that the petitioner raised or reasonably could have raised during that inter partes review.” But, what if a prior art physical product is cumulative of a printed publication raised in an IPR? Courts have been asked to consider whether estoppel attaches to physical products that are described in patents or printed publications. Petitioners need to be aware of this potential situation where prior art materials may not qualify as printed publications for purposes of an IPR proceeding but will be found sufficiently similar to printed publication materials for estoppel to apply in litigation.
Christian Karpinski, Patent Owners Face Unknown Arguments as to Whether IPR Estoppel Attaches to Physical Products, 19 UIC REV. INTELL. PROP. L. 328 (2020)