Joining an Existing Inter Partes Review: Two Rolls of the Same Die

Do two half bites of the same apple equal a whole? This is possibly true if you join a post-grant proceeding at the Patent Office.

It is always fortuitous in life (and patents) to get a “second bite” of the apple, another roll of the die, an unearned and untaxed free spin or a bonus round if you will. Recently, a Court of Appeals panel ruled that joining an existing inter partes review does not trigger the same degree of estoppel (under §315) as if a petitioner had first filed the IPR. Network-1 Technologies v. Hewlett-Packard, Case Nos: 2018-2338, -2339, -2395 & -2396 (Fed. Cir. Sept. 24, 2020). Perhaps this does not provide an entire second bite of the same apple but it is another significant fractional nibble that twice jeopardizes the patent.

IPR estoppel attaches after a final written decision is issued and applies against grounds that were raised or could have been raised. 35 USC §315(e); see also, 37 CFR 42.73(d). The estoppel extends to PTO, ITC and district court litigation. Post-grant reviews and covered business method patent reviews share a similar estoppel provision under §325.

This estoppel encourages petitioners to file their best grounds in post-grant proceedings as they will be prevented from arguing them later. However, a recent decision, Network-1 v. HP, has accused infringers rethinking their IPR filing strategies and considering saving their best bite for last.

In, Network-1 v. HP, the patentee (Network-1) sued HP and others for infringement in the ED of Texas. A different accused infringer, Avaya, was the first to petition for inter partes review. Once the Avaya petition was granted, HP and others filed subsequent petitions along with a motion for joinder under 35 USC §315(c)&(d).

As to joinder of IPRs, §315(c)&(d) enables the PTAB to consolidate IPR petitions regarding the same patent. Joinder may be granted sua sponte or by the motion of either the patentee or petitioner. See MPEP §42.122. Here, the Board denied an earlier petition filed by HP that included grounds different than those originally raised by Avaya and only subsequently joined HP after HP filed another petition with grounds coextensive to those in the Avaya petition.

In the IPR, the Board found none of the petitioned claims to be unpatentable. Thereafter, the District Court of Texas continued to trial where HP argued a different basis for obviousness than that raised with the IPR. The jury found the subject claims obvious. However, the court granted Network-1’s motion for judgement as a matter of law on validity, reasoning that HP should have been estopped from raising its §103 arguments because they “could have been raised” in the IPR under §315(e).

The Court of Appeals panel vacated this judgment and remanded the case with advice that joined IPR petitioners are not estopped from raising arguments that could have been raised as are original petitioners. Chief Judge Prost, writing for the panel, reasoned that joining petitioners cannot raise new grounds with joinders and therefore should not be estopped from subsequently raising said grounds, citing the plain language of §315(e)(2).

"HP's joinder to the Avaya IPR and the estoppel consequences of that joinder are governed by the America Invents Act ("AIA"), which established IPR proceedings. According to the AIA, under 35 U.S.C. § 315(c), HP was permitted to join the Avaya IPR "as a party" even though HP was time-barred under § 315(b) from bringing its own petition. But, as we held in Facebook, Inc. v. Windy City Innovations, LLC, the joinder provision does not permit a joining party to bring into the proceeding new grounds that were not already instituted. Facebook, Inc. v. Windy City Innovations, LLC, 973 F.3d 1321, 1334-37, No. 18-1400 (Fed. Cir. Sept. 4, 2020). Rather, it may only join the already-instituted proceeding as a party. Id.

Following a final written decision in an IPR, the AIA provides for statutory estoppel under 35 U.S.C. § 315(e) to limit the invalidity challenges that an IPR petitioner may bring in a separate action involving the same patent claims. With respect to district court actions, § 315(e)(2) states:

CIVIL ACTIONS AND OTHER PROCEEDINGS.— The petitioner in an inter partes review of a claim in a patent under this chapter that results in a final written decision under section 318(a) ... may not assert in ... a civil action arising in whole or in part under section 1338 of title 28 ... that the claim is invalid on any ground that the petitioner raised or reasonably could have raised during that inter partes review.

35 U.S.C. § 315(e)(2) (emphases added). Thus, according to the statute, a party is only estopped from challenging claims in the final written decision based on grounds that it "raised or reasonably could have raised" during the IPR. Because a joining party cannot bring with it grounds other than those already instituted, that party is not statutorily estopped from raising other invalidity grounds."

In other words, joining petitioners are limited in the grounds they can raise by the scope of the originally filed petition. So, raising the unheard grounds thereafter is not truly a “second bite at the apple.” Since joining petitioners could not have raised the additional grounds under §315(e) they should not be estopped from doing so in subsequent petitions.

Though additional invalidity challenges brought by a joining IPR petitioner may not technically be a second bite at the apple, multiple challenges diversify infringement risks, giving petitioners more rolls of the die and chances to reduce their liability. Considering Network-1 there are significant benefits to joining an IPR rather than being the first to file one. Patentees often sue multiple parties simultaneously. This regularly results in manifold IPR petitions against the same patent filed at or around the same time to meet §315(b)’s 1-year time window. Network-1, however, presents new incentive to assess pre-existing filings before outlining and filing an IPR petition.

Grounds that could have been raised by the original petitioner are not foreclosed from the joining petitioner in future proceedings inside or outside of the PTO. Accordingly, those unraised grounds can provide a powerful second attempt at invalidity to the joining petitioner. For example, one might purposefully segregate and delay grounds in IPR filings for a subsequent round at the PTAB, if not bound by the time restrictions of §315; or one might file the remaining invalidity challenges in a district court as opposed to making a comprehensive IPR filing. Full estoppel would result with any non-joined-IPR final written decision, of course, but not with the joined filling.

It is therefore wise for accused infringers to assess prior related IPRs before petitioning and where possible to leverage the imbalanced estoppel restrictions between original and joined petitioners. As to patentees, one should also consider this double jeopardy opportunity when weighing continued enforcement against reasonable settlement offers.