Uniloc “Locking” LG & Facebook Out? Not So Fast. CAFC Upholds Board’s “No Estoppel” Finding in Uniloc 2017 LLC v. Facebook Inc.

Posted by Alexandra Kim on May 12, 2021

Joinder may allow a party to challenge patent claims with an IPR even if the one-year time bar in Section 315(b) would otherwise preclude the party from filing a petition for IPR. In Uniloc 2017 LLC v. Facebook Inc., Nos. 19-1688, -1689 (Fed. Cir. 2021), the Federal Circuit resolved whether the joining party can continue the challenge even if the original petitioner no longer can due to estoppel.

Under Section 315(e)(1), when an IPR proceeding results in a final written decision with respect to a patent claim, a petitioner, or the RPI or privy of the petitioner, “may not request or maintain” another IPR that the party “raised or reasonably could have raised” in the prior proceeding. Section 315(e)(1) serves two purposes: it protects the defending party from a second attack on the same claim and ensures that the petitioner can still bring challenges that it has not had a full and fair opportunity to do so.

In Uniloc, after a party joined an ongoing IPR, the original petitioner of that IPR became estopped from continuing its challenge due to its involvement in an earlier IPR challenging claims of the same patent. The question the Federal Circuit faced was whether the joining party was also estopped from continuing the challenge.

On appeal, the Federal Circuit found that moving to join a prior petition alone does not make a party a real party in interest (RPI) or privy of the petitioner. However, the court noted that this is highly fact-dependent. In this case, the Federal Circuit found insufficient evidence that the joining party was a RPI or in privity of the original petitioner. This means that the joining party, merely joining the original petition, was not estopped in challenging the claims.


1. Joinder alone does not burden a party that has joined an IPR with the original petitioner’s estoppel. On the contrary, in an estoppel context, patent owners will need evidence other than joinder to prove a party is a RPI or privy of the petitioner. This may include, for example, evidence of joint funding, of a coordinated IPR effort, or of a sufficiently close relationship such that the party already had a chance to litigate the claim.

2. The decision clarified that when the estoppel-triggering event occurred after institution, PTAB decisions concluding that the estoppel provisions do not apply are reviewable on appeal. Contrast Uniloc with Thryv, Inc. v. Click-to-Call, 140 S. Ct. 1367 (2020) where the Supreme Court ruled that the Federal Circuit may not review PTAB time-bar determinations under Section 315(b) because the one-year time bar is “integral to, indeed a condition on, institution.” Thus, petitioners should avoid relying on the Federal Circuit for judicial review given the limited opportunities for review under Section 314(d).

3. A petitioner is not barred from continuing a challenge to a dependent claim in a second IPR when the same claim was not included in the first IPR. In this case, the Federal Circuit relied on the plain language of Section 315(e)(1) and concluded that the original petitioner was not estopped in challenging the dependent claim because it was not addressed in the final written decision of the first IPR. However, petitioners should still be careful about ongoing IPRs as it may give rise to an estoppel of the petitioners’ separate IPR on the same claims of the patent.

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Topics: Petitioners, Patent Owners, "Federal Circuit", Joinder

The PTAB’s Flexibility In Its Decisions – The Federal Circuit Weighs In

Posted by Susmita Gadre on May 10, 2021

Susmita Gadre

On appeal of a PTAB decision that all claims in a patent on compressing video files were unpatentable, the Federal Circuit clarified two issues. This post considers the second addressed issue – is the PTAB limited to the arguments made by Petitioners? The Federal Circuit found that it is.

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Topics: Petitioners, Prior Art, Obviousness, "Federal Circuit"

The One-Year Time Bar Strikes Again

Posted by Stuart Duncan Smith on Apr 8, 2021

Stuart Duncan Smith

The time bar in Section 315(b) says that IPR may not be instituted if the petition was filed more than one year after the petitioner was “served with a complaint alleging infringement of the patent.” A recent PTAB decision illustrates that petitioners should be wary of stepping over that line, even if there is a dispute about the patent owner’s proof of service.

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Topics: Petitioners, Patent Owners, "Federal Circuit", IPR, PTAB

Federal Circuit Declines to Take Up Winning-Petitioner Estoppel

Posted by Scott Forman on Aug 5, 2019

Scott Forman

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.

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Topics: Petitioners, IPR

Motions to Amend: The Board Invites Alice to the IPR Party

Posted by Nathan Speed on Jan 25, 2019

Nathan Speed

One strategy that a patent owner can pursue in an IPR trial is to file a motion to amend seeking to replace one or more of the challenged claims with substitute claims that neither enlarge the scope of the claims nor introduce new subject matter. When a patent owner files such a motion, the petitioner is permitted to oppose the motion and argue why the substitute claims are not patentable. In a recent decision, the Board reaffirmed that the grounds available for a petitioner to attack the patentability of substitute claims are not limited to anticipation or obviousness, but rather can include other sections under the Patent Statute, including § 101.

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Topics: Petitioners, IPR, patent

Who Bears the Burden in IPR? It Depends on the Argument

Posted by Stuart Duncan Smith on Oct 23, 2018

Stuart Duncan Smith

A hallmark of IPR proceedings is that the petitioner—not the patent owner—has the burden to prove that the challenged claims are unpatentable. This hallmark is statutory as section 316(e) of the American Invents Act (which created IPRs) provides that “the petitioner shall have the burden of proving a proposition of unpatentability.” And yet, a recent decision from the Federal Circuit confirms IPR nonetheless applies the traditional rule that can shift a burden to the patent owner to rebut the petitioner’s prima facie case of obviousness. Patent owners thus cannot blindly rely upon section 316(e) and, in certain circumstances, should consider submitting evidence to defend the claims.

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Topics: Petitioners, Patent Owners

In IPR Petitions, Paste Makes Waste

Posted by Tom Chlebeck on Feb 26, 2018

Tom Chlebeck

The PTAB recently signaled a warning to petitioners about the dangers of third party submissions made during patent prosecution—even during prosecution of a separate but related patent. For patent holders, this warning serves as an opportunity to protect their patents in similar situations. In PGR2017-00038, Live Nation Entertainment, Inc. filed a petition to institute post-grant review of U.S. Patent No. 9,466,035. Live Nation’s arguments were that the claims were patent ineligible under 35 U.S.C. 101 and would have been obvious under 35 U.S.C. 103.

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Topics: Petitioners, Patent Owners

Supreme Court May Let IPRs Continue

Posted by Elizabeth Hudson on Dec 8, 2017

Elizabeth Hudson

Last week, the Supreme Court heard oral arguments in Oil States Energy Services v. Greene’s Energy Group—a case that addresses whether inter partes review unconstitutionally usurps the federal courts’ authority to adjudicate the validity of patents. An examination of the Justices’ questions provides hints of how they are thinking and suggests that IPRs may survive constitutional review.

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Topics: Petitioners, Patent Owners

Supreme Court Suggests a Partial Solution to Partial Institutions

Posted by Elizabeth Hudson on Dec 4, 2017

Elizabeth Hudson

Last week, the U.S. Supreme Court heard oral arguments in two patent cases concerning IPRs. The first case (Oil States Energy Services v. Greene’s Energy Group) has garnered much of the attention because it concerns the constitutionality of IPRs, but the second case (SAS Institute Inc. v. Matal) may actually have a bigger impact on how IPRs work. In SAS, the Supreme Court considered the PTAB’s practice of selecting which challenged claims it reviews, rather than, once it institutes a trial, issuing a final decision on the patentability of all claims challenged in the petition. The oral arguments suggest how the Justices are approaching the case.

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Topics: Petitioners, Patent Owners

Can I Get A Witness—With the Right Experience at the Relevant Time?

Posted by Kevin MacDonald on Oct 27, 2017

Kevin MacDonald

No matter whether you are the patent owner or petitioner in an IPR, expert witness testimony is an important aspect of building your case. The Board relies on expert witnesses to provide insight into the often highly technical aspects of a given case, and will inevitably choose to give more weight to the testimony of one side’s witness over the other. This can be especially true when the testimony of the opposing experts is in direct conflict. So how does the Board choose which expert testimony to give more weight? Sometimes it’s a question of timing, as in the recent decision in Mylan Pharmaceuticals Inc. v. AstraZeneca (IPR2015-01340).

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Topics: Petitioners, Patent Owners, BioPharma

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