The Post-Grant Strategist

Challengers in post-grant proceedings like IPR may not reassert invalidity arguments in court that they “raised or reasonably could have raised” before the PTAB. Several recent cases illustrate that whether a particular invalidity argument “reasonably could have [been] raised” is a fact-intensive question that the parties must be prepared to address. These cases also show that both patent owners and challengers should develop a factual record relating to whether estoppel applies to a given invalidity theory.

(Co-authored by Stuart Duncan Smith)

The statute that created inter partes review (IPR) defines certain situations when IPR is not available. For example, IPR is not available if the petitioner was served with a complaint alleging infringement of the challenged patent more than a year earlier. But if the PTAB institutes an IPR that the statute does not permit, does the patent owner have any way to challenge that institution decision? The obvious answer might seem to be appealing the institution decision to the Federal Circuit Court of Appeals, but the same statute also says the PTAB’s institution decision is “final and nonappealable.” Next month in Thryv, Inc. v. Click-to-Call, the Supreme Court will consider whether patent owners can ask the Federal Circuit to keep IPR within its statutory confines.

Judicial estoppel is an equitable doctrine that precludes a party from taking a position in one proceeding that is inconsistent with a position the party took in a previous proceeding. It can be used as a defensive strategy in an inter partes review, for example, when the patent owner identifies that the petitioner is advancing an argument in its petition that is inconsistent with a position the petitioner took in some other proceeding. However, four recent IPRs, exemplified by IPR2018-00291, highlight that meeting the standard for judicial estoppel is no easy task. 

Under the estoppel provisions of 35 U.S.C. § 315(e), if an IPR results in a final written decision, the petitioner is barred from raising invalidity arguments in court or the ITC based on any grounds the petitioner “raised or reasonably could have raised” in the IPR, which may in practice mean any grounds based on patents or printed publications. Thus, petitioners involved in parallel litigation sometimes assert backup invalidity defenses based on prior art products. Two recent cases demonstrate that while such defenses can avoid estoppel, courts may reject perceived attempts to dodge estoppel by simply repackaging a publication-based ground as a product-based ground.

The Federal Circuit recently declined to consider whether a successful IPR petitioner is estopped from making its winning invalidity arguments in district court. If a winning petitioner does face estoppel, its arguments may be limited to those which could not have been brought through IPR when parallel litigation on the same patent proceeds pending rehearing or appeal of the IPR decision. This view of estoppel would shake up the carefully choreographed interplay between district court litigation and FDA approval of a generic manufacturer’s ANDA envisioned by the Hatch-Waxman Act. However, in BTG International Ltd. v. Amneal Pharmaceuticals LLC, the court found the issue moot after upholding the PTAB’s decision finding the challenged claims obvious.

An IPR follow-on petitioner may find it particularly challenging to select the best prior art references and arguments to submit to the PTAB. To make matters worse, the PTAB may decide to invoke its discretionary denial under 35 U.S.C. § 325(d) if it considers the prior art and/or arguments submitted in the follow-on petition to be the same or substantially the same as those considered during prosecution, in parallel proceedings, or in an earlier-filed IPR petition, even if the follow-on petition is filed by a different entity.

For months, panels at the PTAB have debated the relevance of parallel district court litigation on the PTAB’s discretion under 35 U.S.C. § 314(a) to institute or deny a petition for IPR. On May 7, 2019, the PTAB designated as precedential the NHK Spring Co. v. Intri-Plex Techs. decision that denied institution under § 325(d) and § 314(a), confirming that district court litigation “nearing its final stages” is indeed one relevant factor in deciding whether to institute an IPR.

A critical and early determinant in any procedural review is an examination of the permissibility of individual pieces of evidence. In matters of intellectual property, and particularly in IPRs, the permissibility of evidence often rests on two factors: whether a printed publication was publicly available and the relevant dates of that availability. As more and more companies disseminate disclosures and company information on the internet as a matter-of-course, the determination of both factors is becoming increasingly challenging to parse.

While a line of argument in an IPR may seem promising to a patent owner addressing one particular ground of rejection, it is critical for the patent owner to analyze how the argument may impact other grounds of rejections. A seemingly necessary position against one ground may result in substantially limited options for the patent owner with respect to other rejections. While IPR proceedings are limited by statute to prior art challenges (novelty and obviousness), contingent amendments (substitute claims) are also subject to further analysis (such as scope and written description support). In a recent decision, the PTAB rejected a patent owner’s §§ 102 and 103 arguments relating to substitute claims, and then proceeded to perform an alternative analysis under § 112 (written description), finding that the outcome would not change, in part, because of the patent owner’s own § 102 argument.

Just because your issued patent was examined by the USPTO does not mean that it is free from challenge. Your competitors may, of course, scrutinize your patent and use IPR to challenge its validity—potentially turning your patent shield into a roadmap to their next product. This was the case in a recent IPR.