Case: 22-2064    Document: 47     Page: 1   Filed: 05/02/2024




   United States Court of Appeals
       for the Federal Circuit
                  ______________________

            PACKET INTELLIGENCE LLC,
                 Plaintiff-Appellee

                             v.

 NETSCOUT SYSTEMS, INC., NETSCOUT SYSTEMS
 TEXAS, LLC, FKA TEKTRONIX TEXAS, LLC, DBA
       TEKTRONIX COMMUNICATIONS,
               Defendants-Appellants
              ______________________

                        2022-2064
                  ______________________

    Appeal from the United States District Court for the
 Eastern District of Texas in No. 2:16-cv-00230-JRG, Chief
 Judge J. Rodney Gilstrap.
                  ______________________

                   Decided: May 2, 2024
                  ______________________

      PAUL SKIERMONT, Skiermont Derby LLP, Dallas, TX,
 argued for plaintiff-appellee.  Also represented by
 ALEXANDER EDWARD GASSER, STEVEN WAYNE HARTSELL,
 SARAH ELIZABETH SPIRES; MIEKE K. MALMBERG, Los Ange-
 les, CA.

     MICHAEL JOHN LYONS, Morgan, Lewis & Bockius LLP,
 Palo Alto, CA, argued for defendants-appellants. Also rep-
 resented by AHREN CHRISTIAN HSU-HOFFMAN, AUSTIN
 ZUCK; JASON D. FRANK, Boston, MA; JULIE S. GOLDEMBERG,
Case: 22-2064     Document: 47      Page: 2    Filed: 05/02/2024




 2        PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.




 ERIC KRAEUTLER, Philadelphia, PA; WILLIAM R. PETERSON,
 Houston, TX.
                ______________________

     Before LOURIE, HUGHES, and STARK, Circuit Judges.
 STARK, Circuit Judge.
     NetScout Systems, Inc. and NetScout Systems Texas,
 LLC (collectively, “NetScout”) appeal the amended final
 judgment entered by the U.S. District Court for the East-
 ern District of Texas (“Eastern District”), contending that
 the district court erred in granting enhanced damages for
 willful infringement and in setting the rate and effective
 date for an ongoing royalty. In view of the parallel appeals
 in which we have affirmed the final written decisions of the
 Patent Trial and Appeal Board (“Board”) finding all of the
 patent claims asserted by Packet Intelligence LLC
 (“Packet”) in this case invalid, we vacate the district court’s
 amended final judgment and remand with instructions to
 dismiss the case as moot.
                               I
      This case is before us for the second time. Previously,
 in 2020, we considered NetScout’s appeal from the judg-
 ment of the Eastern District following a bench trial and
 jury verdict. The Eastern District had held: (1) NetScout
 willfully infringed claims 10 and 17 of 

 (“’725 patent”), claims 1 and 5 of 

 (“’751 patent”), and claims 19 and 20 of U.S. Pa-
 tent No. 6,954,789 (“’789 patent”); (2) no asserted claim was
 shown to be unpatentable or invalid under 

, 102(a), or 102(f); and (3) Packet was entitled to (a)
 $3.5 million in pre-suit damages, (b) $2.25 million in post-
 suit damages, (c) $2.8 million in enhanced damages, and
 (d) an ongoing royalty of 1.55% for future infringement. In
 that first appeal, we “reverse[d] the district court’s pre-suit
 damages award and vacate[d] the court’s enhancement of
 that award.” Packet Intel. LLC v. NetScout Sys., Inc., 965
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 PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.           

 (Fed. Cir. 2020) (“Packet I”). We “af-
 firm[ed] the district court’s judgment in all other respects.”
 

 By mandate issued on October 23, 2020, we remanded
 the case to the Eastern District.
     During the pendency of the remand, the Board issued
 final written decisions in inter partes reviews (“IPRs”) ini-
 tiated by third parties Juniper Networks, Inc. and Palo
 Alto Networks, Inc. Those final written decisions found all
 claims asserted in this case unpatentable as obvious. See
 Juniper Networks, Inc. v. Packet Intel. LLC, IPR2020-
 00336, 2021 Pat. App. LEXIS 5456 (P.T.A.B. Sept. 9, 2021)
 (considering ’725 patent); Juniper Networks, Inc. v. Packet
 Intel. LLC, IPR2020-00338, 2021 Pat. App. LEXIS 5520
 (P.T.A.B. Sept. 8, 2021) (considering ’751 patent); Juniper
 Networks, Inc. v. Packet Intel. LLC, IPR2020-00339, 2021
 Pat. App. LEXIS 5525 (P.T.A.B. Sept. 8, 2021) (considering
 ’789 patent). Packet timely appealed the Board’s final writ-
 ten decisions. We coordinated those appeals so they would
 be considered by the same panel deciding this appeal.
     After the Board issued the final written decisions,
 NetScout moved in the Eastern District to dismiss Packet’s
 infringement case against it or, in the alternative, to stay
 the district court litigation until the conclusion of Packet’s
 appeal from the Board’s final written decisions. Packet op-
 posed the motion. At the time, the parties were already in
 the process of litigating the issues we remanded in Packet
 I, which related to enhanced damages and ongoing royal-
 ties.
      On May 4, 2022, the district court denied NetScout’s
 motion to dismiss or stay the case and entered an amended
 final judgment. The amended judgment was based on the
 district court’s evaluation of the contested issues that were
 litigated on the remand from our mandate in Packet I. In
 particular, the court denied NetScout’s request to reevalu-
 ate the factors it had originally considered in deciding to
 enhance damages, concluding that the mandate rule
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 4        PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.




 precluded such reconsideration – and, in any event, that
 reconsideration would have resulted in the same decision
 to enhance post-suit damages.            The district court’s
 amended judgment also eliminated all pre-suit damages
 and retained the full $2.25 million in post-suit damages. It
 also reduced the enhanced damages from $2.8 million to
 approximately $1.1 million, a reduction in the same pro-
 portion as the reduction in compensatory damages (from
 the prior total of $5.75 million (i.e., $3.5 + $2.25 million) to
 the new amount of $2.25 million). Finally, the district
 court reset the ongoing royalty rate, dropping it from 1.55%
 to 1.355%, effective as of the date of the amended final
 judgment (May 4, 2022), rejecting NetScout’s request to re-
 duce it to 1.16% as well as Packet’s preference that it re-
 main at 1.55%.
     On May 31, 2022, NetScout filed a motion pursuant to
 Federal Rule of Civil Procedure 59(e), seeking to make the
 effective date of the reduced ongoing royalty rate (1.355%)
 October 23, 2020, the date the Packet I mandate had is-
 sued. On June 21, 2022, the district court denied the mo-
 tion, finding that NetScout had failed to sufficiently raise
 the effective date issue prior to the entry of the May 4, 2022
 amended final judgment.
    NetScout timely appealed. We have jurisdiction under
 

(a)(1).
                                II
      NetScout contends that if, in the co-pending appeals
 from the Board, we affirm the Board’s findings that the
 claims asserted in this litigation are unpatentable, such af-
 firmance would have “an immediate issue-preclusive ef-
 fect,” leaving Packet unable to “collect on an outstanding
 monetary damages award for patent infringement.” Appel-
 lant’s Br. at 13. In support of its position, NetScout cites
 several cases in which we vacated district court judgments
 of patent infringement after affirming intervening un-
 patentability findings from the United States Patent and
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 PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.           5



 Trademark Office (“PTO”). See, e.g., VirnetX Inc. v. Apple
 Inc., 

, at *1 (Fed. Cir. Mar. 31, 2023)
 (“VirnetX II”); Chrimar Sys., Inc. v. ALE USA Inc., 

, 857-58 (Fed. Cir. 2019); XY, LLC v. Trans Ova
 Genetics, L.C., 

 (Fed. Cir. 2018); Frese-
 nius USA, Inc. v. Baxter Int’l, Inc., 

 (Fed. Cir. 2013) (“Fresenius II”). In response, Packet at-
 tempts to distinguish these cases as arising in a different
 procedural posture than the one we confront here today. In
 Packet’s view, the only issue we need to decide is whether
 our decision in Packet I rendered this case sufficiently final
 such that it is immune to the Board’s subsequent determi-
 nation of unpatentability.
     While Packet has accurately characterized the issue
 presented, the answer it urges us to give is incorrect.
 Based on our precedents, including those cited by
 NetScout, Packet’s infringement judgment was not final
 before the Board’s unpatentability determinations were af-
 firmed. We are, thus, compelled to order that Packet’s pa-
 tent infringement claims be dismissed as moot.
                               A
     Our decision in Fresenius II is most instructive. There,
 Fresenius USA, Inc. and Fresenius Medical Care Holdings,
 Inc. (collectively, “Fresenius”) brought a declaratory judg-
 ment action in the United States District Court for the
 Northern District of California (“Northern District”)
 against Baxter International, Inc. and Baxter Healthcare
 Corp. (collectively, “Baxter”), alleging that claims of 

 (“’434 patent”) and two other patents
 were invalid and not infringed. See Fresenius II, 

. Baxter counterclaimed for infringement. See
 

. Following claim construction, Fresenius stip-
 ulated to infringement but continued to insist that the as-
 serted claims were invalid. See 

. The Northern
 District then held a trial on invalidity, after which the jury
 returned a verdict in favor of Fresenius, finding all
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 6        PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.




 asserted claims invalid. See 

 The district court granted
 Baxter’s motion for judgment as a matter of law (“JMOL”)
 that some of its asserted claims, including those in the ’434
 patent, were not invalid. See 

. Following an-
 other jury trial on damages, the district court awarded
 Baxter pre-verdict damages of more than $14 million, as
 well as post-verdict royalties and a permanent injunction.
 See 

.
      The parties then appealed to us. On appeal, we af-
 firmed the Northern District’s determination that the
 claims of the ’434 patent were not invalid. See Fresenius
 USA, Inc. v. Baxter Int’l, Inc., 

 (Fed. Cir. 2009) (“Fresenius I”). We also reversed the dis-
 trict court’s determination that the claims of the other two
 patents were not invalid. Because we had concluded that
 two of the three patents asserted by Baxter were invalid,
 we vacated the district court’s permanent injunction and
 royalty awards and remanded for reconsideration of these
 issues in light of our modification of the judgment. See 

.
      On remand, the ’434 patent expired, rendering the per-
 manent injunction issue moot. See Fresenius II, 

. Fresenius moved for a new trial on pre-verdict
 damages for infringement of the ’434 patent, contending
 that a new trial was warranted “because the jury returned
 a single, generalized verdict covering all asserted claims
 from three Baxter patents.” Fresenius USA, Inc. v. Baxter
 Int’l, Inc., 

, at *2 (N.D. Cal. May 26,
 2011). The district court denied the motion, finding that
 “[n]othing in the mandate in this case indicates that dam-
 ages for infringement was an issue for remand.” 

 On
 March 16, 2012, the district court entered final judgment,
 awarding Baxter pre-verdict damages based on the original
 jury award and post-verdict damages at a reduced royalty
 rate. See Fresenius II, 

.
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 PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.            7



     While the district court litigation was ongoing, Frese-
 nius requested ex parte reexamination of certain claims of
 the ’434 patent, including those asserted by Baxter in the
 district court litigation. See 

 The PTO examiner found
 the reexamined claims unpatentable as obvious, a determi-
 nation that was later affirmed by the Board of Patent Ap-
 peals and Interferences, see Ex Parte Baxter Int’l, Inc., No.
 2009-006493, 

, at *1 (B.P.A.I. Mar. 18,
 2010), and then by us, see In re Baxter Int’l, Inc., 

 (Fed. Cir. 2012). Our mandate issued on No-
 vember 2, 2012, and Baxter did not petition for a writ of
 certiorari from the Supreme Court. See Fresenius II, 

.
      In the parties’ second appeal from the Northern Dis-
 trict, Fresenius challenged the pre-verdict damages award
 and Baxter challenged the post-verdict royalties. See 

. Fresenius also argued that Baxter no longer had a
 cause of action for infringement, “[i]n light of the cancella-
 tion of the asserted claims of the ’434 patent, and the fact
 that the infringement suit remain[ed] pending before” our
 court. 

.
      We agreed with Fresenius. We vacated the district
 court’s judgment and remanded with instructions to dis-
 miss the case as moot. See 

 In doing so, we rejected
 Baxter’s argument that “the cancellation of the asserted
 claims cannot be given effect . . . because the validity of the
 ’434 patent and Fresenius’ liability for infringement of that
 patent were conclusively decided in 2007.” 

. It
 was Baxter’s view that even before the first appeal, the dis-
 trict court’s 2007 judgment was “final” and “binding” on the
 parties, thus having “res judicata effect within the pending
 litigation.” 

     In reaching our different conclusion, we emphasized
 the importance of “distinguish[ing] between different con-
 cepts of finality.” 

. We explained that we were
 “not dealing with finality for purposes of determining the
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 8        PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.




 potential res judicata effect of this infringement litigation
 on another suit” but were “concerned instead with whether
 the judgment in this infringement case is sufficiently final
 so that it is immune to the effect of the final judgment in
 the PTO proceedings, as affirmed by this court.” 

. As to this latter concept of finality – which is the
 same concept of finality at issue here in NetScout’s appeal
 – we held that in order for a judgment to be “sufficiently
 final to prevent the application of” an intervening un-
 patentability finding, “the litigation must be entirely con-
 cluded so that the cause of action against the infringer was
 merged into a final judgment [and is] one that ends the lit-
 igation on the merits and leaves nothing for the court to do
 but execute the judgment.” 

 (internal alterations and
 quotation marks omitted).
                              B
      Applying Fresenius II here leads inexorably to the con-
 clusion that Packet’s infringement case against NetScout
 remains pending and, thus, is not immune to the Board’s
 now-affirmed findings of unpatentability. Our decision in
 Packet I plainly did not move this case to a stage that
 “leaves nothing for the court to do but execute the judg-
 ment.” 

 Instead, we remanded for the district court to
 excise pre-suit damages and enhanced damages related to
 pre-suit damages. Even Packet cannot bring itself to say
 that our mandate in Packet I left “nothing for the court to
 do but execute the judgment.” 

 In its recitation of the
 situation here, Packet writes that the Packet I mandate
 “left nothing for the district court to do other than to re-
 move the pre-suit damages and any enhancement tied
 thereto.” Appellee’s Br. at 55 (emphasis added). This is
 self-evidently something more than “nothing . . . but exe-
 cute the judgment.” Fresenius II, 

.
     In Fresenius II, we held that a patent infringement
 judgment is immune to subsequent unpatentability find-
 ings only when that judgment “ends the litigation on the
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 PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.           9



 merits and leaves nothing for the court to do but execute
 the judgment.” 

 (internal quotation marks
 omitted). Our remand in Packet I did not end the litigation
 on the merits. Instead, to comply with our remand, the dis-
 trict court was required to modify its original judgment to
 eliminate a portion of its compensatory damages award
 and to determine the impact of that elimination on the
 proper amount of enhanced damages. Again, this is some-
 thing more than “nothing . . . but execute the judgment.” 1
 

     That this case was not, on remand from Packet I, “final”
 in the Fresenius II sense is further illustrated by the exten-
 sive litigation that occurred following our mandate. On re-
 mand, the Eastern District received voluminous briefing
 related to enhanced damages (as well as the ongoing roy-
 alty rate and NetScout’s motion to dismiss or stay). The
 district court comprehensively analyzed the disputed is-
 sues presented to it. Eventually, and not unreasonably, the
 remand litigation lasted for more than 16 months. This
 amount of litigation is more than “nothing . . . but execute
 the judgment.” 

     The remand also had a substantial financial impact.
 Whereas in the original judgment NetScout was ordered to
 pay Packet $5.75 million in damages, $2.8 million in en-
 hancement, and ongoing royalties at a rate of 1.55%, after
 the remand the amended judgment required NetScout to
 pay Packet only $2.25 million in damages, approximately
 $1.1 million in enhancement, and an ongoing royalty rate


     1   We are not holding that the need for a formulaic
 calculation of the exact dollar amount of, for example, pre-
 judgment or post-judgment interest or post-judgment run-
 ning royalties necessarily renders a judgment non-immune
 to a subsequent patentability determination under the rule
 of Fresenius II. These issues are not presented to us in this
 case.
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 10       PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.




 of 1.355%. These financial consequences are a further in-
 dication that something more than “nothing . . . but exe-
 cute the judgment” was required on remand from Packet I.
 

                               C
      Packet emphasizes that “this case is in a distinctly dif-
 ferent procedural posture” from Fresenius II and our other
 decisions, because “this Court has already affirmed liabil-
 ity and damages and did not remand to resolve open dam-
 ages issues with the possibility for further review by this
 Court.” Appellee’s Br. at 57. Packet’s description of the
 posture here is not quite right, as the impact of excision of
 pre-judgment damages on enhanced damages was an issue
 left open by our remand in Packet I. But even if Packet’s
 characterization were accurate, our precedents hold that
 remanded patent cases remain vulnerable to post-mandate
 developments concerning patentability, even if liability –
 including patent validity – has already been conclusively
 resolved by appellate review.
      As we already noted, by the time we issued Fresenius
 II, 

, that case had been before us in a
 previous appeal, in which we had affirmed the district
 court’s grant of JMOL that the claims of the ’434 patent
 were not invalid. See Fresenius I, 

. None-
 theless, after we subsequently affirmed the PTO’s reexam-
 ination cancellation of the ’434 patent claims on which the
 district court judgment had been based, we ordered dismis-
 sal of the infringement case. See Fresenius II, 

. We held that “the district court must apply interven-
 ing legal developments affecting the asserted patent’s va-
 lidity, even if the court of appeals already decided the
 validity issue the other way . . . because the appellate man-
 date had not ended the case.” 

.
    We predicated our Fresenius II holding on the Supreme
 Court’s similar determination in Simmons Co. v. Grier
 Bros. Co., 

 (1922). In Simmons, the patentee
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 PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.           11



 had sued the defendant for patent infringement and also
 for unfair competition. See 

. The district court
 found for the patentee on both claims. See 

. On
 appeal, the Third Circuit affirmed the district court judg-
 ment of unfair competition but reversed as to patent in-
 fringement, holding that the asserted claims – which were
 contained in a reissue patent – were void “upon the ground
 that [they] broadened the original patent.” 

. The
 Third Circuit issued a mandate instructing the district
 court to modify its decree in accordance with the appellate
 opinion. 

 Accordingly, on remand, the district court dis-
 missed the patent infringement claim, granted injunctive
 relief on the unfair competition claim, and ordered the de-
 fendant to pay “damages sustained by reason of unfair
 trade to be ascertained and reported by a master.” 

      While the unfair competition damages accounting was
 still pending before the master, the Supreme Court held in
 an unrelated case that the reissued claims of the same pa-
 tent that was asserted in Simmons were valid. See 

. Citing this development as “new facts that had arisen
 since the decree entered,” 

 (internal quotation marks
 omitted), the patentee in Simmons asked the district court
 to review its previous dismissal of the patent infringement
 claim. The district court did so, entering a new judgment
 sustaining the validity of the reissued patent claims and
 finding the defendant liable for infringement. After the
 Third Circuit again reversed the district court, see 

 at 86-
 87, the Supreme Court reversed, thereby affirming the
 judgment of patent infringement. In doing so, the Supreme
 Court explained that because “[t]he suit was still pending”
 at the time the Supreme Court had issued its determina-
 tion in the other case, it was “eminently proper that the
 decree in the present suit should be made to conform to”
 the Supreme Court’s intervening decision. 

. The
 Court observed that proceedings with respect to the unfair
 competition claim were still ongoing: specifically, “an in-
 quiry before a master still was necessary before final
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 12       PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.




 decree could pass; an inquiry not formal or ministerial, but
 judicial in order to ascertain the amount of the damages to
 be awarded.” 

. While the patent infringement
 claim had been concluded on the merits, the case itself re-
 mained pending, which meant it could still be impacted by
 subsequent developments, including a determination re-
 garding patent validity. See id.; see also Chrimar, 785 F.
 App’x at 856 (“A case is generally to be considered as a
 whole in judging its pendency.”).
      We summarized the Simmons holding in Fresenius II
 as follows: “even though there had been an appellate deci-
 sion entirely resolving the patent infringement claims, be-
 cause there had not yet been a final judgment on the unfair
 competition claims, the Supreme Court’s intervening deci-
 sion [on patent validity in the other case] was binding as to
 the infringement claims.” 

. In other
 words, to defeat application of a subsequent patentability
 determination, a case needs to reach the stage that “leaves
 nothing for the court to do but execute the judgment.” 

. If the case, as a whole, has not reached that stage,
 the judgment may be impacted by subsequent develop-
 ments, even developments that relate to issues of patent
 validity that had themselves been fully resolved in an ear-
 lier appeal.
     Hence, again, even accepting Packet’s contention that
 this case, following the Packet I remand, was at a more ad-
 vanced stage than were the cases we addressed in Frese-
 nius II, Chrimar, and XY, the issue of finality in this
 context is not one of degree. Instead, we apply a “yes/no”
 analysis: is there, post-mandate, anything left to do other
 than execute the judgment? If the answer is “yes,” then the
 case as a whole is not “final” and is not, therefore, immune
 to the impact of subsequent developments with respect to
 the validity of the patents on which its infringement and
 invalidity claims are based. Only if the answer is “no” has
 the Fresenius II finality requirement been met, rendering
 the judgment immune to subsequent developments.
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 PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.          13



                               D
      Our decisions in Chrimar, XY, and VirnetX are all con-
 sistent with our holding today. In Chrimar, 785 F. App’x
 at 855, after the patentee prevailed at a jury trial, the dis-
 trict court entered judgment awarding damages and ongo-
 ing royalties. On appeal, we affirmed the district court on
 all issues presented to us except for the construction of a
 single claim term, which we reversed, requiring us to re-
 mand the case for further proceedings. Shortly before we
 issued our mandate, the Board issued final written deci-
 sions in IPRs brought by third parties, finding all asserted
 claims unpatentable. On remand, the accused infringer
 “sought certain relief based on the Board’s unpatentability
 decisions,” including “a stay of the ongoing royalties, []or a
 stay of the proceedings as a whole, and for relief from the
 judgment.” Id. The district court denied the motion to
 stay, declined to grant relief from the judgment, and en-
 tered an amended final judgment which “included the con-
 tinuing order to pay ongoing royalties.” Id.
      The accused infringer appealed to us again. We heard
 oral argument in its appeal on the same day we considered
 the patentee’s appeal from the Board’s unpatentability de-
 terminations. Later we affirmed the Board. See id. at 855-
 56. Then, in the accused infringer’s appeal from the dis-
 trict court’s amended judgment, we found that the district
 court case had “remain[ed] pending” during the IPRs, so
 “the now-affirmed unpatentability determinations by the
 Board as to all claims at issue must be given effect in this
 case.” Id. at 858. We vacated the district court’s amended
 final judgment and remanded the case with instructions
 that it be dismissed.
     Similarly, in XY, 

, we decided that we
 did not need to address the accused infringer’s invalidity
 arguments in its appeal from the district court’s denial of a
 new trial on invalidity, in view of our same-day affirmance
 in a separate appeal stemming from the Board’s IPR
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 14       PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.




 decision that the relevant claims were unpatentable. We
 explained that our affirmance of the Board’s determination
 of unpatentability “renders final a judgment on the inva-
 lidity of the [asserted patent], and has an immediate issue-
 preclusive effect on any pending or co-pending actions in-
 volving the patent.” 

 We noted that “the fact that the
 Defendant in this case and the Petitioners . . . at the Board
 were different parties is of no consequence.” 

.
 We dismissed the accused infringer’s appeal as moot.
     We confronted a similar situation most recently in Vir-
 netX II, 

, at *1. There, in an earlier ap-
 peal, we had affirmed the district court’s judgment of
 infringement as to two asserted patents but had simulta-
 neously reversed as to two others. See VirnetX Inc. v. Apple
 Inc., 

, 798 (Fed. Cir. 2019) (“VirnetX I”).
 We had also vacated the damages award and remanded for
 further proceedings. See VirnetX II, 

, at
 *1. After the district court entered an amended judgment
 on remand, containing a revised damages award, the ac-
 cused infringer appealed again. In the meantime, the
 Board found the patent claims giving rise to the infringe-
 ment judgment unpatentable, and we affirmed the Board.
 We then determined that, given that “we ha[d] affirmed the
 Board’s finding of unpatentability,” the patentee “ha[d] lost
 its cause of action, and its dispute” with the accused in-
 fringer was moot. 

 Therefore, we vacated the district
 court’s judgment and remanded with instructions to dis-
 miss the case.
     Therefore, in accord with Fresenius II, as well as our
 numerous similar decisions, we are required to apply here
 our affirmance of the Board’s determination that the pa-
 tent claims on which Packet’s judgment of infringement
 against NetScout is based are unpatentable. Packet’s suit
 against NetScout was not “final” as it proceeded on remand
 in the Eastern District following our mandate in Packet I,
 even though we had at that point affirmed a judgment of
 infringement of valid patent claims. Packet’s judgment
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 PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.              15



 had not reached a stage at which it would be immune to
 subsequent developments relating to the patentability of
 the patent claims on which it was based. Thus, we must
 remand this case with instructions that it be dismissed.
                                III
     Packet raises one additional argument against our dis-
 position here. Packet contends that even if its case was not
 “final” when it was proceeding on remand in the Eastern
 District, it is sufficiently final now. That is because, in
 Packet’s view, once the amended judgment was entered on
 May 4, 2022, there was then nothing for any court to do
 other than execute that judgment. Packet’s contention
 lacks merit because it fails to accept that this case remains
 pending as a result of NetScout’s non-frivolous appeal of
 the district court’s amended judgment.
     Although Packet does not dispute that NetScout had a
 right to appeal aspects of the amended judgment that were
 unfavorable to it, see generally Chrimar, 785 F. App’x at
 856 (“[F]inality generally does not exist when a direct ap-
 peal is still pending . . . .”), it insists that NetScout only ap-
 pealed issues that are “insubstantial and legally
 untenable,” Appellee’s Br. at 59. It cannot be, according to
 Packet, that an otherwise “final” case can remain pending
 – and therefore vulnerable to subsequent developments re-
 lating to patentability – simply by asserting frivolous argu-
 ments on appeal.
     Packet correctly points out that we have previously
 contemplated this type of situation. In Chrimar, 785 F.
 App’x at 858, we recognized we might someday encounter
 a party engaged in “an abuse of the judicial process in the
 form of presentation of insubstantial arguments.” For in-
 stance, an accused infringer knowing of the pendency of
 parallel Board proceedings might try to keep its infringe-
 ment case alive by pressing a frivolous appeal. In Chrimar,
 we did not need to decide the “questions that might arise
 about application of the Fresenius/Simmons preclusion
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 16       PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.




 principle to a case that has been kept alive only on insub-
 stantial grounds.” Id. at 856. And we reach the same con-
 clusion here. Even assuming that an appeal consisting
 solely of insubstantial issues would render a district court
 judgment “final” for Fresenius II purposes, NetScout’s ap-
 pellate issues are not insubstantial.
     The issue regarding the impact on the enhanced dam-
 ages award of our mandated requirement to vacate the
 award of pre-suit damages is not insubstantial. As we have
 already explained, in our Packet I mandate we reversed the
 district court’s award of pre-suit damages and vacated “any
 enhancement thereof.” 965 F.3d at 1316. We left it to the
 district court on remand to assess the impact of the reduc-
 tion in damages on the enhanced damages portion of the
 judgment. The parties vigorously contested this issue on
 remand, so it was subject to extensive litigation. Specifi-
 cally, Packet sought to continue to receive the full enhance-
 ment it had been awarded prior to Packet I, arguing that
 the finding of willful infringement was based on NetScout’s
 post-suit conduct and, anyway, Packet I did not alter the
 district court’s analysis of the enhancement factors set out
 in Read Corp. v. Portec, Inc., 

 (Fed.
 Cir. 1992). By contrast, NetScout urged the district court
 to reconsider the Read factors and, after doing so, decide to
 award no enhanced damages.
     The district court rejected both parties’ positions. It in-
 stead reduced its pre-mandate enhanced damages award
 by the same proportion that it had reduced the compensa-
 tory damages award, i.e., by approximately 61%.
     NetScout’s appeal of the district court’s resolution of
 this dispute is not insubstantial. If we were to reach the
 merits of the appeal, and NetScout were to prevail, the ap-
 proximately $1.1 million in enhanced damages would be re-
 duced or possibly even eliminated.
     Similarly, the issue regarding the ongoing royalty rate
 for NetScout’s post-judgment infringement is also not
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 PACKET INTELLIGENCE LLC v. NETSCOUT SYSTEMS, INC.          17



 insubstantial. On remand from Packet I, NetScout sought
 to reduce this rate from 1.55% to 1.16%, based on changed
 circumstances, including our vacating the pre-suit dam-
 ages award and the Board’s final written decisions finding
 all asserted claims to be unpatentable. Packet countered
 that no modification was warranted and, in the alternative,
 the rate should not be reduced to any lower than 1.3%.
     After receiving extensive briefing and hearing argu-
 ment, the district court rejected both proposals, setting the
 ongoing royalty rate at 1.355%. NetScout’s appeal, by
 which it asks us to adjust the ongoing royalty rate to its
 preferred 1.16%, is not insubstantial. Although Packet in-
 sists there would not be a large, direct financial impact, see
 Appellee’s Br. at 60 (suggesting NetScout would save only
 $13,000 by prevailing on this portion of its appeal), we have
 been given no persuasive reason to deem the appellate is-
 sue (including its potential financial impact) to be insub-
 stantial.
     For these reasons, the ongoing pendency of this case is
 not the result of NetScout’s assertion of issues that are “in-
 substantial and legally untenable.” Id. at 59. Thus, again,
 even assuming there is an exception to the Fresenius II fi-
 nality doctrine for cases that are kept alive solely by such
 frivolities, this is not such case. Hence, the Board’s un-
 patentability determinations must be given effect, which
 requires that we remand this case for dismissal.
                              IV
     We have considered the parties’ remaining arguments
 and find them unpersuasive. Accordingly, we vacate the
 district court’s amended final judgment and remand with
 instructions to dismiss the case as moot.
                VACATED AND REMANDED
                            COSTS
 No costs.