In the years since the creation of inter partes review (IPR)proceedings, US courts and the US Patent & Trademark Office (USPTO) have continued to interpret and clarify the statutes, rules, and procedures governing these proceedings. One question that remains an important part of this developing area of the law is the scope and applicability of statutory estoppel under 35 U.S.C. §315. Particularly, after the Federal Circuit's decision in Shaw Industries Group v Automated Creel Systems, and the US Supreme Court's subsequent decision in SAS Institute v Iancu, the landscape surrounding IPR estoppel continues to shift . Understanding how courts are applying estoppel is essential to preparing effective strategies for petitioners and patent owners alike. Background Statutory estoppel under section 315 In 2011, the Leahy-Smith America Invents Act (AIA) created new procedures for challenging patents before the USPTO. IPR is the most common type of these proceedings, permitting a party to petition the Patent Trial and Appeal Board (PTAB) to review the patentability of an issued patent based on challenges that one or more claims of the patent are anticipated or obvious under 35 U.S.C. §§102 or 103.1   An IPR petitioner may rely only on printed publications and patents dated before the effective filing date of the challenged US patent.2

The IPR proceeding can be divided into two separate phases. First, a panel of three PTAB judges must decide whether to institute IPR by determining whether the information presented in the petition provides a "reasonable likelihood that the petitioner would prevail with respect to at least one of the claims challenged in the petition."3  If the panel declines to institute IPR, then the proceeding terminates. If, however, the IPR is instituted, the second phase of the proceeding begins, and the panel reviews the merits of the instituted grounds. The proceeding terminates, generally within a year, with the panel issuing a final written decision.4

One legislative goal of IPR and other post-grant proceedings was to provide an opportunity to challenge a patent outside of district court litigation.5But in creating such proceedings, Congress also recognized the need to protect patent owners from repeated and burdensome attacks. And Congress included statutory estoppel in 35 U.S.C. §315 as a consequence for petitioning for IPR. 35 U.S.C. §315(e)(1) sets forth the estoppel before the USPTO:

"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), or the real party in interest or privy of the petitioner, may not request or maintain a proceeding before the Office with respect to that claim on any ground that the petitioner raised or reasonably could have raised during that inter partes review."

35 U.S.C. §315(e)(2) sets forth the estoppel in civil actions:

"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), or the real party in interest or privy of the petitioner, may not assert either in a civil action arising in whole or in part under section 1338 of title 28 or in a proceeding before the International Trade Commission under section 337 of the Tariff Act of 1930 that the claim is invalid on any ground that the petitioner raised or reasonably could have raised during that inter partes review." 

Estoppel is triggered when the PTAB issues a final written decision. And, under the statute, estoppel limits the challenges a petitioner – its real parties in interest or those in privity with it – can rely on in any other ongoing or later proceeding brought in a US district court, the US International Trade Commission (ITC), or the PTAB. The scope of this statutory estoppel, especially as to what challenges a petitioner "reasonably could have raised during" the IPR, has been debated and is likely to evolve.

Shaw and the Scope of Statutory Estoppel Under Section 315 in District Courts

Section 315 states that estoppel results from the PTAB's issuance of a final nal written decision, but courts have not reached consensus on the scope of that estoppel in ongoing or later filed civil actions. In particular, courts have questioned what challenges a petitioner actually raised or reasonably could have raised during an IPR. Nor has the PTAB definitively set forth its view on the scope of estoppel in ongoing or later-filed petitions.

Before the US Supreme Court's decision in SAS Institute v Iancu,6  the analysis for applying statutory estoppel was particularly complicated by PTAB procedures that allowed partial institution of IPR petitions. These procedures meant that the PTAB could institute some of the challenges raised in a petition and simultaneously decline, or deny, others. Only instituted grounds proceeded to a final written decision. Th is resulted in many IPRs where some challenges and even some claims were never addressed during IPR or in a final written decision. In 2016, the Federal Circuit approved this practice of partial institution in Synopsys v Mentor Graphics Corp.7and SAS Institute v ComplementSoft ,8finding that there was "no statutory requirement that the Board's final decision address every claim raised in a petition for inter partes review."9

Because of partial institution, courts and practitioners alike were left questioning whether statutory estoppel would apply to petitioned but non-instituted challenges.10  The Federal Circuit offered guidance in Shaw Industries Group v Automated Creel Systems, when it held that estoppel under section 315 does not apply to claims or grounds that were not instituted.11  In Shaw, the PTAB partially instituted IPR with respect to some challenges and declined to institute the remaining challenges because it determined that they were redundant to the instituted grounds.12  On appeal, among other issues, the petitioner argued that it was improper for the PTAB to decline to institute grounds on the basis of "redundancy" and requested relief from the court.13  In particular, the petitioner argued that, without relief, it would otherwise be estopped from raising the noninstituted grounds in future proceedings.14  The Federal Circuit disagreed. The court explained that because "[b]oth parts of §315(e) create estoppel for arguments 'on any ground that the petitioner raised or reasonably could have raised during that inter partes review'" and because "IPR does not begin until it is instituted," it was impossible for the petitioner to have "raised or reasonably [to] have raised" the non-instituted grounds during IPR.15  Thus, according to the Federal Circuit, no estoppel applied to petitioned but non-instituted grounds.16

After Shaw, courts reached inconsistent conclusions with respect to the scope of IPR estoppel. Some courts applied Shaw broadly, finding that the Federal Circuit's decision exempts any ground not raised "during" IPR, i.e., after er institution. For example, in Verinata Health v Ariosa Diagnostics, the Northern District of California found that, under Shaw, estoppel applies only to grounds that were both raised in the petition and instituted in the IPR proceeding.17  There, the court reasoned that in Shaw, the Federal Circuit interpreted section 315 "literally," limiting estoppel under the provision "to grounds actually instituted", thereby ensuring "that estoppel applies only to those arguments, or potential arguments, that received (or reasonably could have received) proper judicial attention."18  The District of Delaware reached a similar conclusion in Intellectual Ventures I LLC v Toshiba Corp., first acknowledging that extending estoppel to "prior art references that were never presented to the PTAB at all (despite their public nature) confounds the very purpose of this parallel administrative proceeding," but nevertheless determining that "the court cannot divine a reasoned way around the Federal Circuit's [literal] interpretation [of the statute] in Shaw."19

In contrast, other courts read Shaw as creating a narrow exception, resulting in a broad application of estoppel. For example, in Biscotti v Microsoft , the Eastern District of Texas determined that Shaw only exempts grounds raised in a petition but not instituted for procedural reasons (e.g., redundancy) and applied estoppel to grounds that a petitioner did raise (i.e., were instituted) or could have raised (e.g., grounds that a petitioner could have included in the petition but chose not to).20  Similarly, in Oil-Dri Corp. of America v Nestle Purina Petcare, the Northern District of Illinois declined to extend Shaw to exclude grounds that a petitioner could have raised in a petition but did not.21  The court in Oil-Dri recognized that where an invalidity challenge is properly presented in a petition, "due process and fairness" prevents a petitioner from being stripped of "a full opportunity to be heard" through "no fault" of its own.22  But, the court also explained that "when a petitioner simply does not raise invalidity grounds it reasonably could have raised in an IPR petition, the situation is different."23  The Western District of Wisconsin reached a similar determination in Douglas Dynamics v Meyer Products.24

Thus, district courts narrowly applying Shaw have limited its holding to exempt only those grounds petitioned but not instituted and apply estoppel to grounds that were not petitioned but reasonably could have been.25  In Oil-Dri, for example, the court reasoned that a decision to forgo estoppel against nonpetitioned grounds could incentivize petitioners to carefully craft IPR petitions such that they would be able to bring multiple (staged) challenges.26  Courts narrowly applying Shaw, like the Northern District of Illinois also did in Clearlamp v LKQ, have generally found non-petitioned grounds estopped if, before filing the petition, the non-petitioned prior art could have been found by a skilled searcher's diligent search.27  Thus, not all subsequent challenges would be estopped, just those based on prior art that the court found a petitioner should have been aware of.

SAS and PTAB Institution of All Grounds

Earlier this year, in SAS Institute, the US Supreme Court reversed the Federal Circuit's decision28  permitting the PTAB's practice of "partial institution."29  The Court held that the PTAB "must address every claim the petitioner has challenged."30  Though the Court did not explicitly rule that the PTAB must institute review on every challenge petitioned (because sometimes petitioners challenge the same claim with multiple prior art grounds), the USPTO responded by issuing "guidance" that it would either institute all grounds against all claims challenged in a petition for IPR or deny all grounds against all claims.31  The Federal Circuit approved the PTAB's all-or-nothing approach for instituting IPR and found "pervasive support" in the Supreme Court's SAS decision for the "[e]qual treatment of claims and grounds for institution purposes."32  The Federal Circuit also held that where an appeal from an IPR is pending at the Federal Circuit arising from a final written decision that did not address all petitioned grounds and claims, then "it is appropriate to remand to the PTAB to consider non-instituted claims as well as non-instituted grounds."33  The Federal Circuit has further held that a party has not "waived its right to seek SAS-based relief due to failure to argue against partial institution before the PTAB."34

SiOnyx and Scope of Statutory Estoppel Under Section 315 Post-SAS

The Supreme Court's decision in SAS arguably simplifies estoppel practice by preventing cases that include partially instituted IPR petitions. The decision does not, however, resolve all questions. As an initial matter, SAS does not directly overrule or change the law on the scope of statutory estoppel. The decision does not mention either the Federal Circuit's decision in Shaw or that decision's effect on statutory estoppel. However, in the wake of SAS, district courts will be tasked with determining if, and in what manner, pre-SAS case law regarding statutory estoppel will survive and how, post-SAS, the Federal Circuit's Shaw decision affects, if at all, the application of estoppel.

In August 2018, in SiOnyx v Hamamatsu Photonics K.K.,35  the District Court of Massachusetts had one of the earliest opportunities to consider the scope of IPR estoppel following SAS. There, SiOnyx filed suit against several defendants alleging infringement.36  The defendants counterclaimed in the district court that the asserted claims of SiOnyx's patents were invalid.37  Following SiOnyx's initial complaint, one defendant also petitioned for IPR of SiOnyx's patents before the PTAB.38 For one of the patents, the PTAB partially instituted the petition and ultimately reached a final written decision, finding that the instituted claims were unpatentable.39SiOnyx subsequently appealed the unpatentability ruling to the Federal Circuit.40The defendants did not cross-appeal the PTAB's decision to decline to institute review for some of the claims and grounds.41

While SiOnyx's appeal from the PTAB was ongoing, the district court litigation continued in parallel and the Supreme Court issued its decision in SAS. In the district court case, following the PTAB's final written decision, SiOnyx moved for summary judgment on the ground that defendants are estopped from arguing that "any of the asserted claims of [SiOnyx's patent] are invalid" based on (1) claims and grounds actually discussed in the PTAB's final written decision; (2) claims and grounds that were not instituted; and (3) claims and grounds that were not raised in the petition.42

The SiOnyx court's analysis of estoppel in each of these instances provides a first look at how district courts may apply statutory estoppel post-SAS in pending disputes where the PTAB partially instituted pre-SAS and in future disputes where the PTAB cannot partially institute post-SAS.

Estoppel Against Claims and Grounds Discussed in the Final Written Decision

Consistent with the language of section 315(e) and the Federal Circuit's reasoning in Shaw,43  the court in SiOnyx held that grounds included in a petition for IPR that result in a final written decision trigger estoppel.44  And the district court explained: "defendants are clearly estopped from asserting any claims and grounds" that were instituted and resulted in a final written decision.45

In so doing, the court addressed the defendants' argument that estoppel should not apply because the "PTAB's decision is still pending" on appeal.46  The district court responded that the pending nature of the appeal did not aff ect estoppel because the statute makes no distinction between successful and unsuccessful grounds.47  The court therefore found that it did not matter whether the PTAB's decision was affirmed or reversed – in either scenario, defendants were estopped from asserting the grounds included in the PTAB's final written decision.48  This finding by the SiOnyx court conflicts with the Eastern District of Wisconsin's conclusion in Milwaukee Electrical Tool v Snap-On, which purportedly limits statutory estoppel to "unsuccessful" petitioners that had failed at the final written decision to prove unpatentability.49

As the court's analysis in SiOynx shows, petitioners and patent owners should expect courts to apply estoppel against any claims and grounds included in the petition for IPR that are instituted and result in a final written decision. The court's analysis also highlights that questions about the finality of final written decisions may still exist among the various district courts. In view of these questions and the potential for different outcomes, parties should consider the possibility that a district court may apply estoppel after the PTAB issues its final written decision even if rights for rehearing or appeal remain.

Estoppel Against Claims and Grounds the PTAB Declined to Institute

The court in SiOnyx also addressed claims and grounds that the PTAB declined to institute. The court acknowledged the Federal Circuit had permitted petitioners on appeal to seek remand for consideration of non-instituted grounds post-SAS, in situations where the PTAB partially instituted IPR, even though the PTAB found all instituted claims unpatentable.50  Despite this opportunity, the court noted that the petitioner (defendant) in SiOnyx did not seek remand for consideration of non-instituted grounds. And, as a result, the court reasoned that the noninstituted grounds "reasonably could have been raised" before the PTAB because the defendant could have raised them on appeal with remand to the PTAB for consideration.51  Due to the defendant's failure to seek remand, the district court held that the defendant was estopped from raising any non-instituted grounds against any claim in the district court.52

Following district court decisions pre-SAS and the SiOnyx court's analysis post-SAS, it appears likely that estoppel will apply to all grounds petitioned when an instituted IPR results in a final written decision. The PTAB can no longer partially institute a petition, effectively eliminating the concern from Shaw. For partially instituted petitions filed pre-SAS that are still pending, the court's holding in SiOnyx, though not binding, may also provide persuasive support for another court to likewise apply estoppel based on that party's failure to appeal or seek a remand for consideration of the non-instituted grounds. Th us, petitioners should consider preserving all arguments to ensure that their rights with respect to estoppel are preserved.

Estoppel Against Claims and Grounds Not Raised Before the PTAB

The facts in SiOnyx presented two additional grounds that defendants argued were not raised before the PTAB but were brought for the first time in the district court. The court addressed each ground to determine if estoppel should apply.

First, the court considered whether a ground that included prior art that was not asserted in any petitioned grounds reasonably could have been raised and whether estoppel should apply.53  The court acknowledged, without expressly citing Shaw, that pre- SAS, courts were divided with respect to whether non-petitioned grounds would be estopped from future litigation.54  The SiOnyx court determined that post-SAS, the broad application of Shaw, like in Verinata, "could not be correct" because the statutory language "reasonably could have raised" could only have meaning if it refers to grounds that were not actually in the IPR petition.55  

The SiOnyx court then turned to determining the applicable standard to determine which non-petitioned grounds reasonably could have been raised. The court adopted the test that other district courts applied, like the court in Clearlamp, and held statutory estoppel applied to grounds that are based on a patent or printed publication that "a skilled searcher conducting a diligent search could have been expected to discover."56  The court also stated that such a determination "appears" to be a question of fact that should be determined by the fact-finder (i.e., the jury in a jury trial or a judge in a bench trial) after the parties present evidence and arguments.57

Applying this test to the facts in SiOnyx, the court appeared to place the burden on SiOnyx to show that a skilled searcher would have discovered the prior art.58  The court found that SiOnyx had not presented evidence to meet this burden at the summary judgment stage and that contrary evidence existed in the record.59  The court therefore found that there was a genuine question of material fact with respect to the discoverability of the non-petitioned prior art and held that (at the summary judgment stage) that defendants would not be estopped from relying on the reference.60

Second, the court considered whether invalidity grounds based on defendant's actual product in combination with prior art asserted in the petition should be estopped.61  The defendants argued that they could not be estopped from asserting grounds based on the product because a product is not a patent or printed publication and could not (by statute) have been raised in the IPR.62  The defendants also pointed to a separate district court case in Star Envirotech v Redline Detection, which considered a plaintiff 's motion to strike invalidity contentions based on statutory estoppel.63  The court in Star found that claim elements disclosed by a physical product could not have been met by printed, prior art manuals of the same product and therefore estoppel did not apply because IPR is limited to only grounds based on patents or printed publications.64

SiOnyx countered that the defendants were actually relying on printed datasheets and a manufacturing specification that described the physical product, which it argued could have been raised in IPR.65  And the court noted that parties may not avoid statutory estoppel provisions "by dressing up a ground based on publicly available" printed publications as a ground based on a physical product.66  While the parties dispute also focused on the extent that the defendants were relying on the documents rather than the physical product, the court found that the defendants were not estopped from relying on the physical product as prior art.67

As the SiOnyx court's analysis shows, the scope of statutory estoppel for non-petitioned grounds post-SAS remains a question. And, ancillary to the question of scope, estoppel disputes raise evidential and burden of persuasion questions that will likely be raised in the district courts and Federal Circuit. For example, parties may dispute whether the patent owner (plaintiff) must show estoppel applies or whether the petitioner (defendant) must show estoppel does not apply. The evidence required and the placement of the burden may depend on the stage of the litigation. Moreover, courts may be persuaded, like the court in SiOnyx, that given the holding in SAS, and the prohibition of partial IPR institution, broader estoppel practice (narrowly applying Shaw) is the correct analysis going forward and, non-petitioned grounds that reasonably could have been raised may be estopped. Regardless of the scope of estoppel, petitioners and patent owners should be prepared to present evidence to support their arguments both on the applicable scope of estoppel and how that scope applies to the facts of their particular case. Both parties face strategic decisions – for petitioners, when and where to raise prior art challenges – for patent owners, when and where to raise estoppel arguments.

Estoppel and "Real Parties in Interest"

The case in SiOnyx also highlights an important consideration on the application of statutory estoppel against parties, especially co-defendants, that are not the petitioner before the PTAB. Section 315 provides that estoppel applies to the petitioner "or the real party in interest or privy of the petitioner."68

In SiOnyx, there were three co-defendants in the district court litigation. The petition for IPR was brought by one of the three defendants but identified only one of the other two co- defendants as a real party in interest.69  The third co-defendant was not named in the IPR.70  When SiOnyx moved for summary judgment, arguing statutory estoppel after the PTAB's final written decision, the defendants did not raise any arguments that the unnamed co-defendant should be treated differently.71  As a result, the court determined that all three defendants would be treated similarly with respect to estoppel.72

It is not clear how the court would have addressed this issue if the defendants had argued estoppel should not apply against the unnamed co-defendant. However, the legislative history regarding the statutory creation of IPRs might suggest Congress endorsed an expansive application of estoppel to unnamed parties. For example, Senator Kyl explained that "privity is an equitable rule that takes into account the 'practical situation,' and should extend to parties to transactions and other activities relating to the property in question."73  Senator Kyl also stated that "extending could-have-raised estoppel to privies will help ensure that if an inter partes review is instituted while litigation is pending that review will completely substitute for at least the patents-and-printed publications portion of the civil litigation."74  Senator Schumer similarly stated that "[a] 'privy' is a party that has a direct relationship to the petitioner with respect to the allegedly infringing product or service."75  While legislative history is not binding, courts sometimes find it persuasive, and it at least shows that broad estoppel was at least debated as part of the statutory scheme. Nonetheless, this remains an open question.


IPR estoppel was pre-SAS and remains post-SAS a developing area of US patent law. While SAS itself did not directly deal with IPR estoppel, it will most likely have an effect on it. Before SAS, the PTAB's practice of partially instituting some but not all of the grounds presented in a petition gave rise to the Federal Circuit's estoppel decision in Shaw. That decision itself led to disagreement among the district courts on how narrowly or broadly Shaw should be applied. Now, after SAS, the PTAB must institute all grounds and the specific concern that led to Shaw is no longer pertinent. While SAS may arguably alleviate some of the tension that followed Shaw, many questions regarding the scope and applicability of IPR estoppel remain.

Parties should carefully consider the possible uses and ramifications of estoppel in making strategic decisions regarding patents that are subject to an IPR.


See 35 U.S.C. §§311-19 (2012).

2Id. §312.

3Id. §314(a).

Id. §316.

5157 Cong. Rec. S1360-94 (daily ed. 8 March 2011) (statement of Sen. Grassley) (purpose is to "ensure that if an inter partes review is instituted while litigation is pending, that review will completely substitute for at least the patents-and-printed-publications portion of the civil litigation.").

6138 S. Ct. 1348 (2018) ("SAS").

7814 F.3d 1309, 1316-17 (Fed. Cir. 2016).

8825 F.3d 1341, 1352 (Fed. Cir. 2016) ("ComplementSoft "), rev'd and remanded sub nom. SAS Inst., Inc. v Iancu, 138 S. Ct. 1348 (2018).

9Synopsys, 814 F.3d at 1316-17; ComplementSoft , 825 F.3d at 1352.

10See, e.g., ComplementSoft , 825 F.3d at 1356-59 (Newman J, concurring in part and dissenting in part) ("Among the consequences of the USPTO's curious and unforeseen practice, partial review does not estop unreviewed claims as to either validity or invalidity, thereby adding to the litigants' burden rather than lightening it.").

11817 F.3d 1293, 1299-1300 (Fed. Cir. 2016); see also HP Inc. v MPHJ Tech. Invs., LLC, 817 F.3d 1339, 1347 (Fed. Cir. 2016).

12Shaw, 817 F.3d at 1297.

13Id. at 1298-1300.


15 Id. at 1300.

16 Id.

17 No. 12-cv-05501-SI, 2017 WL 235048, at *3 (N.D. Cal. Jan. 19, 2017); see also Koninklijke Philips N.V. v Wangs Alliance  Corp., No. 14-12298-DJC, 2018 WL 283893, at *3-4 (D. Mass. Jan. 2, 2018); Finjan, Inc. v Blue Coat Sys., LLC, 283 F. Supp. 3d 839, 855-57 (N.D. Cal. 2017).

18Verinata, 2017 WL 235048, at *3.

19221 F. Supp. 3d 534, 553-54 (D. Del. 2016).

20No. 2:13-CV-01015-JRG-RSP, 2017 WL 2526231 (E.D. Tex. 11 May 2017).

21No. 15-cv-1067, 2017 WL 3278915, at *9 (N.D. Ill. 2 August 2017).

22 Id. at *8.

23 Id.

24. No. 14-CV-886-JDP, 2017 WL 1382556, at *4 (W.D. Wis. 18 April 2017) ("[U]ntil Shaw is limited or reconsidered, this court will not apply §315(e)(2) estoppel to non-instituted grounds, but it will apply §315(e)(2) estoppel to grounds not asserted in the IPR petition... ").

25Oil-Dri, 2017 WL 3278915, at *9; Douglas Dynamics, 2017 WL 1382556, at *4; see also Cobalt Boats, LLC v Sea Ray Boats, Inc., No. 2:15-cv-21, 2017 WL 2605977, at *2-3 (E.D. Va. 5 June 2017); Parallel Networks Licensing, LLC v Int'l Bus. Machs. Corp., No. 13-2072 (KAJ), 2017 WL 1045912, at *11-12 (D. Del. 22 February 2017); Clearlamp, LLC v LKQ Corp., No. 12-C-2533, 2016 WL 4734389, at *8-9 (N.D. Ill. 18 March 2016).

26 Oil-Dri, 2017 WL 3278915, at *9 (internal citations omitted); see also Douglas Dynamics, 2017 WL 1382556, at *4 (stating that applying Shaw as in Verinata "undermines the purported effi ciency of IPR").

27Clearlamp, 2016 WL 4734389, at *8; see also Oil-Dri, 2017 WL 3278915, at *8-10; Douglas Dynamics, 2017 WL 1382556, at *4-5; Parallel Networks, 2017 WL 1045912, at *11.

28See ComplementSoft , 825 F.3d 1341.

29 SAS, 138 S. Ct. at 1354.

30 Id.

31USPTO, Guidance on the Impact of SAS on AIA Trial Proceedings (26 April 2018),

32PGS Geophysical AS v Iancu, 891 F.3d 1354, 1360 (Fed. Cir. 2018); see also BioDelivery Scis. Int'l, Inc. v Aquestive Therapeutics, Inc., 898 F.3d 1205, 1209-10 (Fed. Cir. 2018) ("We agree that SAS requires institution on all challenged claims and all challenged grounds.").

33BioDelivery Sci., 898 F.3d at 1208; Polaris Indus. Inc. v Arctic Cat, Inc., 724 F. App'x 948, 948-49 (Fed. Cir. 2018); see also Ulthera, Inc.
v DermaFocus LLC, No. 2018-1542, 2018 WL 4087900 (Fed. Cir. 25 May 2018); Baker Hughes Oilfield Operations, LLC v Smith  Int'l, Inc., Nos. 2018-1754, -1755, 2018 WL 4087705 (Fed. Cir. 30 May 2018).

34BioDelivery Sci., 898 F.3d at 1208; Polaris, 724 F. App'x at 949 (citing Hormel v Helvering, 312 US 552, 558-59 (1941)).

35No. 15-13488-FDS, 2018 WL 4177941, at *1, *8 (D. Mass. 30 August 2018).

36 See SiOnyx, 2018 WL 4177941, at *10. One additional patent owned by Harvard and exclusively licensed to SiOnyx was also asserted. Id. Plaintiff s also brought allegations based on breach of contract and correction of inventorship with respect to several patents owned by defendants. One additional patent owned by Harvard and exclusively licensed to SiOnyx was also asserted. Id. at *1.

37See id., at *16.



40 Id.

41Id.; see also Cuozzo Speed Techs., LLC v Lee,136 S. Ct. 2131, 2134 (2016) (holding that 35 U.S.C. §314(d) prevents appeal of PTAB
institution decisions).

42 SiOnyx, 2018 WL 4177941, at *16-21.

43See Shaw, 817 F.3d at 1300.

44See 35 U.S.C. §315(e)(2) (2012) (IPR petitioner may not assert, in a civil action or ITC proceeding, any ground that the petitioner raised or reasonably could have raised during an IPR "that results in a final written decision." [emphasis added]); see also, e.g., Star Envirotech, Inc. v Reline Detection, LLC, No. SACV 12-08161 JGB, 2015 WL 4744394, at *3 n.3 (C.D. Cal. 29 January 2015) ("IPR estoppel attaches once the PTAB issues a final written decision.").

45SiOnyx, 2018 WL 4177941, at *18.

46 Id.

47 Id.


49271 F. Supp. 3d 990, 1027 (E.D. Wis. 2017).

50SiOnyx, 2018 WL 4177941, at *18; see also supra section (I)(c).

51SiOnyx, 2018 WL 4177941, at *18.



54 Id.


56Id. at *19 (internal citations omitted).


58Id. (internal citations omitted).

59 Id.

60Id. at *20.

61 Id.

62Id.; see also 35 U.S.C. §311(b) (2012) (limiting IPR only on the basis of prior art consisting of patents and printed publications).

632015 WL 4744394, at *4 (C.D. Cal. 29 January 2015).


65SiOnyx, 2018 WL 4177941, at *20.

66 Id. (citing Milwaukee Elec., 271 F. Supp. 3d at 1032; Clearlamp, 2016 WL 4734389, at *9).


68 35 U.S.C. §315(e)(1), (e)(2).

69SiOnyx, 2018 WL 4177941, at *11.



72 Id.

73157 Cong. Rec. S1376 (daily ed. 8 March 2011) (statement of Sen. Kyl).


75 Id. at S5432 (daily ed. 8 September 2011) (statement of Sen. Schumer).

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