Court Opinion

ID: 6349190
Source: CourtListenerOpinion
Date Created: 2022-06-13 14:00:33.718561+00
Date Added: 2024-06-11T09:12:05.703334
License: Public Domain

Case: 21-1969   Document: 50     Page: 1   Filed: 06/13/2022

   United States Court of Appeals
       for the Federal Circuit
                 ______________________

    UNIVERSITY OF MASSACHUSETTS, CARMEL
             LABORATORIES, LLC,
               Plaintiffs-Appellants

                            v.

          L’ORÉAL S.A., L’ORÉAL USA, INC.,
                Defendants-Appellees
               ______________________

                       2021-1969
                 ______________________

     Appeal from the United States District Court for the
 District of Delaware in No. 1:17-cv-00868-CFC-SRF, Judge
 Colm F. Connolly.
                  ______________________

                 Decided: June 13, 2022
                 ______________________

    JEFFREY A. LAMKEN, MoloLamken LLP, Washington,
 DC, argued for plaintiffs-appellants. Also represented by
 CALEB HAYES-DEATS; LAUREN F. DAYTON, New York, NY;
 BEATRICE FRANKLIN, TAMAR LUSZTIG, Susman Godfrey
 LLP, New York, NY; JUSTIN ADATTO NELSON, Houston, TX.

    ERIC WILLIAM DITTMANN, Paul Hastings LLP, New
 York, NY, argued for defendants-appellees. Also repre-
 sented by ISAAC S. ASHKENAZI, KARTHIK RAM KASARANENI,
 BRUCE M. WEXLER; STEPHEN BLAKE KINNAIRD, NAVEEN
Case: 21-1969    Document: 50      Page: 2    Filed: 06/13/2022

 2              UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.

 MODI, Washington, DC; KATHERINE FRENCK MURRAY, Ellis
 George Cipollone O'Brien Annaguey LLP, Los Angeles, CA.
                  ______________________

     Before PROST, MAYER, and TARANTO, Circuit Judges.
 TARANTO, Circuit Judge.
      This appeal is from a judgment in a patent-infringe-
 ment action involving U.S. Patent Nos. 6,423,327 and
 6,645,513, which are related as parent and child and which
 are owned by University of Massachusetts and exclusively
 licensed to Carmel Laboratories, LLC (hereinafter referred
 to together as UMass). UMass filed the action in the Dis-
 trict of Delaware against L’Oréal S.A. and its American
 subsidiary, L’Oréal USA, Inc. (hereinafter referred to to-
 gether as L’Oréal unless otherwise noted), alleging that
 they were infringing the two patents. When L’Oréal S.A.,
 which is based in France, moved to dismiss the action
 against it on the ground that the Delaware forum lacked
 personal jurisdiction over it, the district court granted the
 motion without permitting UMass to conduct jurisdictional
 discovery. See Memorandum Order, University of Massa-
 chusetts v. L’Oréal S.A., No. 1:17-cv-00868 (D. Del. May 17,
 2019), ECF No. 36 (Personal Jurisdiction Order); Report
 and Recommendation, University of Massachusetts v.
 L’Oréal S.A., No. 1:17-cv-00868 (D. Del. Nov. 13, 2018),
 ECF No. 31 (Personal Jurisdiction Report and Recommen-
 dation). With the case then proceeding only against
 L’Oréal USA, the district court ruled on a dispute about the
 proper construction of one limitation of the claim that is
 representative for present purposes. See J.A. 3719–21
 (Hearing Tr. at 56:22–58:16); see also Claim Construction
 Order, University of Massachusetts v. L’Oréal USA, Inc.,
 No. 1:17-cv-00868 (D. Del. Apr. 9, 2020), ECF No. 114
 (Claim Construction Order). Relying on that construction,
 the district court subsequently held another limitation of
 the claim indefinite. University of Massachusetts v. L’Oréal
 USA, Inc., 534 F. Supp. 3d 349 (D. Del. 2021) (Summary
Case: 21-1969    Document: 50         Page: 3    Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS       v. L’ORÉAL S.A.             3

 Judgment Opinion). On that basis, the court entered a fi-
 nal judgment of invalidity against UMass.
     UMass challenges both the indefiniteness and per-
 sonal-jurisdiction rulings. On UMass’s first challenge, we
 address the claim construction on which the indefiniteness
 ruling depends, and we reject the district court’s construc-
 tion as understood by both parties on appeal. This conclu-
 sion justifies our vacating the indefiniteness ruling and
 remanding for further proceedings. On UMass’s second
 challenge, we conclude that UMass was entitled to jurisdic-
 tional discovery, and we therefore vacate the dismissal of
 L’Oréal S.A.
                               I
      According to the specification of the ’327 patent (and
 the materially identical specification of the ’513 patent),
 human skin includes a surface layer called the epidermis
 and a deeper layer called the dermis. ’327 patent, col. 1,
 lines 20–21. The dermis includes a variety of dermal cell
 types, as well as proteins such as collagen and elastin. Id.,
 col. 1, lines 24–34; J.A. 2871–72. The ’327 patent and the
 related ’513 patent, both titled “Treatment of Skin with
 Adenosine or Adenosine Analog,” describe methods for en-
 hancing the condition of non-diseased skin by topical appli-
 cation of compositions containing a naturally occurring
 nucleoside called adenosine. ’327 patent, col. 1, lines 37–
 47; J.A. 2877. Independent claim 1 of the ’327 patent is
 representative for our purposes and recites:
     1. A method for enhancing the condition of unbro-
     ken skin of a mammal by reducing one or more of
     wrinkling, roughness, dryness, or laxity of the skin,
     without increasing dermal cell proliferation, the
     method comprising topically applying to the skin a
     composition comprising a concentration of adeno-
     sine in an amount effective to enhance the condi-
     tion of the skin without increasing dermal cell
Case: 21-1969    Document: 50      Page: 4    Filed: 06/13/2022

 4              UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.

     proliferation, wherein the adenosine concentration
     applied to the dermal cells is 10-4 M to 10-7 M.
 Id., col. 10, lines 18–26 (emphases added). “M” refers to the
 common measure of concentration, molar concentration,
 i.e., moles per liter. L’Oréal Response Br. 22; see also J.A.
 2882 n.2. Claim 1 of the ’513 patent is identical except that
 its wherein clause recites a range of 10-3 M to 10-7 M—in
 other words, it allows a higher adenosine concentration.
 ’513 patent, col. 10, lines 18–26.
     On June 30, 2017, UMass filed a complaint in the
 United States District Court for the District of Delaware
 against L’Oréal S.A. and L’Oréal USA for infringement of
 the ’327 and ’513 patents. J.A. 49–62; see also J.A. 228–40
 (First Amended Complaint). A few months later, L’Oréal
 S.A. filed a motion under Federal Rule of Civil Procedure
 12(b)(2) asking that it be dismissed from the case on the
 ground that the forum lacked personal jurisdiction over it,
 attaching a declaration from an employee of L’Oréal USA.
 J.A. 521; J.A. 551–54. UMass opposed the motion, arguing,
 among other things, that it should be granted discovery re-
 lated to personal jurisdiction. J.A. 557–78.
     In March 2018, before the magistrate judge to whom
 the matter was assigned ruled on the Rule 12(b)(2) motion,
 L’Oréal USA filed petitions for inter partes reviews of the
 ’327 and ’513 patents under 35 U.S.C. §§ 311–19 with the
 Patent and Trademark Office’s Patent Trial and Appeal
 Board. In September 2018, however, the Board denied in-
 stitution. See J.A. 2798–817 (’327 patent); J.A. 2819–37
 (’513 patent); see also J.A. 2839–46 (decision denying re-
 hearing for ’327 patent). In denying review, the Board con-
 strued the wherein clause of the above-quoted claim, which
 requires that “the adenosine concentration applied to the
 dermal cells” have a molar concentration within a specified
 range.    Applying the district-court claim-construction
 standard, J.A. 2803; J.A. 2824, the Board rejected L’Oréal
 USA’s argument that the recited concentration range is the
Case: 21-1969     Document: 50      Page: 5    Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.               5

 adenosine concentration in the composition that is topically
 applied to the skin surface (epidermis), and instead
 adopted UMass’s construction that the recited concentra-
 tion range is the adenosine concentration applied to the
 dermal cells in the dermis below the epidermis. See J.A.
 2805–12; J.A. 2825–32. The Board did not further specify
 the meaning of the concentration “applied to the dermal
 cells”; in particular, the Board did not specify what is meas-
 ured for the liter volume that defines the denominator of
 the moles/liter ratio, M. The Board did not require further
 definition for its non-institution ruling because it con-
 cluded that L’Oréal USA had not pointed to any measure-
 ment of concentrations beneath the skin surface in the
 prior art invoked against the patents. See J.A. 2812–16;
 J.A. 2833–36. Because the Board denied institution, those
 preliminary determinations were “final and nonappeala-
 ble” under 35 U.S.C. § 314(d).
      Back in the district court, on November 13, 2018, the
 magistrate judge recommended granting L’Oréal S.A.’s
 Rule 12(b)(2) motion without allowing discovery. Personal
 Jurisdiction Report and Recommendation at 17–26. Over
 UMass’s objection, J.A. 1251–56, the district court adopted
 the magistrate judge’s recommendations, dismissing
 L’Oréal S.A. from the suit, Personal Jurisdiction Order at
 1–4. Thereafter, L’Oréal USA asked the district court to
 construe the wherein clause. The district court reached the
 same conclusion as the Board: The recited concentration
 range refers to “the concentration as it is applied to the der-
 mal cells,” not the concentration of adenosine in the com-
 position that is applied to the epidermis. J.A. 3719–21
 (Hearing Tr. at 56:1–58:16). Like the Board, the district
 court did not further specify the meaning of “the adenosine
 concentration applied to the dermal cells.” Indeed, the dis-
 trict court entered an order stating that the wherein clause
 “has its plain and ordinary meaning without the need for
 further construction.” Claim Construction Order at 1.
Case: 21-1969    Document: 50      Page: 6    Filed: 06/13/2022

 6              UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.

      In September 2020, L’Oréal USA moved for summary
 judgment on multiple grounds. In one motion, L’Oréal
 USA focused on the claim language preceding the wherein
 clause (the so-called skin-enhancement clause)—requiring
 “topically applying to the skin a composition comprising a
 concentration of adenosine in an amount effective to en-
 hance the condition of the skin, without increasing dermal
 cell proliferation.” L’Oréal USA argued that the language
 would be indefinite if the court (1) maintained its earlier
 ruling on the wherein clause and (2) further concluded that
 the recited concentration range in the wherein clause does
 not establish the adenosine concentration in the composi-
 tion topically applied to the skin in the skin-enhancement
 clause. See J.A. 11794–812; J.A. 18823–34.
     In April 2021, the district court granted L’Oréal USA’s
 summary-judgment motion on that ground, relying on the
 earlier claim-construction ruling that the concentration re-
 cited in the wherein clause concerns application to the sub-
 surface dermal cells and emphasizing the distinctness of
 that concentration and the concentration recited in the
 skin-enhancement clause. Summary Judgment Opinion,
 534 F. Supp. 3d at 353–57. The district court then entered
 its final judgment of invalidity of the asserted claims.
 UMass timely appealed. We have jurisdiction pursuant to
 28 U.S.C. § 1295(a)(1).
                              II
     On appeal, UMass first challenges the district court’s
 indefiniteness determination. UMass’s argument and the
 district court’s ruling on indefiniteness rely on resolution
 of a dispute about claim construction, specifically, about
 the proper understanding of the wherein clause and how it
 relates to the skin-enhancement clause. Notably, UMass
 insists that the “concentration” in the wherein clause is the
 concentration of adenosine in the dermis after it has en-
 tered the dermis, i.e., it measures the molar concentration
 M as the number of moles of adenosine divided by the
Case: 21-1969    Document: 50      Page: 7    Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS   v. L’ORÉAL S.A.              7

 volume (liters) of the dermis itself. See Oral Arg. at 12:54–
 13:16; J.A. 12437. We turn initially to this dispute, and we
 reject UMass’s view and conclude that the district court
 erred. Our conclusion eliminates an important premise of
 the indefiniteness determination, warranting vacatur of
 that determination and remand for further proceedings.
      We decide claim construction here de novo, as the dis-
 trict court’s claim-construction ruling rests only on intrin-
 sic evidence, Intel Corp. v. Qualcomm Inc., 21 F.4th 801,
 808 (Fed. Cir. 2021), and the intrinsic evidence likewise de-
 termines our construction. “We generally give words of a
 claim their ordinary meaning in the context of the claim
 and the whole patent document; the specification particu-
 larly, but also the prosecution history, informs the deter-
 mination of claim meaning in context, including by
 resolving ambiguities; and even if the meaning is plain on
 the face of the claim language, the patentee can, by acting
 with sufficient clarity, disclaim such a plain meaning or
 prescribe a special definition.” World Class Technology
 Corp. v. Ormco Corp., 769 F.3d 1120, 1123 (Fed. Cir. 2014)
 (citing Phillips v. AWH Corp., 415 F.3d 1303, 1312–17 (Fed.
 Cir. 2005) (en banc); and then Thorner v. Sony Computer
 Entertainment America LLC, 669 F.3d 1362, 1365 (Fed.
 Cir. 2012)).
     “The prosecution history, in particular, ‘may be critical
 in interpreting disputed claim terms,’” and “even where
 ‘prosecution history statements do not rise to the level of
 unmistakable disavowal, they do inform the claim con-
 struction.’” Personalized Media Communications, LLC v.
 Apple Inc., 952 F.3d 1336, 1340 (Fed. Cir. 2020) (quoting
 Sunovion Pharmaceuticals, Inc. v. Teva Pharmaceuticals
 USA, Inc., 731 F.3d 1271, 1276 (Fed. Cir. 2013); and then
 Shire Development, LLC v. Watson Pharmaceuticals, Inc.,
 787 F.3d 1359, 1366 (Fed. Cir. 2015)). “‘We cannot look at
 the ordinary meaning of the term . . . in a vacuum. Rather,
 we must look at the ordinary meaning in the context of the
 written description and the prosecution history.’” Medrad,
Case: 21-1969      Document: 50      Page: 8     Filed: 06/13/2022

 8               UNIVERSITY OF MASSACHUSETTS      v. L’ORÉAL S.A.

 Inc. v. MRI Devices Corp., 401 F.3d 1313, 1319 (Fed. Cir.
 2005) (quoting DeMarini Sports, Inc. v. Worth, Inc., 239
 F.3d 1314, 1324 (Fed. Cir. 2001)). We conclude that the
 claim language is not plain in the respect at issue and that
 the proper interpretation is determined by the specification
 and, most pointedly, by the prosecution history.
                                A
     We first conclude that the relevant claim language, es-
 pecially when viewed in the context of the whole claim, is
 not plain on its face, much less plain in supporting UMass’s
 interpretation of it. See IGT v. Bally Gaming Int’l, Inc., 659
 F.3d 1109, 1117 (Fed. Cir. 2011) (“Extracting a single word
 from a claim divorced from the surrounding limitations can
 lead construction astray.”). The language contains evident
 uncertainties and indicators pointing against UMass’s
 view.
     A starting point is the fact relied on by the Board and
 district court: The wherein clause refers to “the adenosine
 concentration applied to the dermal cells,” whereas the pre-
 ceding skin-enhancement clause refers to “topically apply-
 ing to the skin a composition comprising a concentration of
 adenosine.” The contrast in the object of the variants of the
 same verb is suggestive of a difference. See J.A. 2806–07
 (Board resting primarily on this rationale); J.A. 3720
 (Hearing Tr. at 57:1–24) (similar for district court); see, e.g.,
 Hamilton Beach Brands, Inc. v. f’real Foods, LLC, 908 F.3d
 1328, 1340 (Fed. Cir. 2018). But this difference in one
 phrase is only a starting point. The specifics of the overall
 language immediately complicate the picture and push
 against UMass’s argument.
     One reason is the particular verb with the different ob-
 jects. The word “applied” is capable of covering both direct
 application (to the skin surface) and indirect application (to
 the sub-surface layer). See J.A. 2845 (Board noting broad
 dictionary definition of “apply”). UMass itself, before the
 Board, confirmed the availability of the indirect meaning
Case: 21-1969    Document: 50      Page: 9    Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS   v. L’ORÉAL S.A.              9

 when it asserted that the specification’s phrase, “prefera-
 bly applied by topical routes,” ’327 patent, col. 5, line 12,
 meant “‘preferably applied [to the dermal cells] by topical
 routes,’” J.A. 2864 (emphasis and alteration added by
 UMass). As a result, the fact that one phrase using a form
 of “apply” refers to the “skin” and the other to the “dermal
 cells” does not mean that different things are being applied:
 The same thing can be applied directly to one object and
 indirectly to the other.
      Language of the wherein clause affirmatively suggests
 such a connection between the two clauses at issue. The
 wherein clause refers to “the adenosine concentration ap-
 plied to the dermal cells.” That is the language for invoking
 an antecedent—for repeating, not departing from, the
 claim’s prior reference to “a concentration of adenosine” in-
 cluded in the topically applied composition. J.A. 3720
 (Hearing Tr. at 57:10–20); see, e.g., NTP, Inc. v. Research
 in Motion, Ltd., 418 F.3d 1282, 1306 (Fed. Cir. 2005), abro-
 gated on other grounds by Zoltek Corp. v. United States, 672
 F.3d 1309, 1323 (Fed. Cir. 2012) (en banc); Griffin v. Ber-
 tina, 285 F.3d 1029, 1033–34 (Fed. Cir. 2002). So viewing
 claim 1 as involving one concentration, rather than two,
 also fits the dependent claims, some of which likewise refer
 to “the adenosine concentration,” ’327 patent, col. 10, lines
 29–32 (emphasis added) (claims 3 and 4), suggesting a pre-
 supposition that there is only one such concentration called
 for by independent claim 1.
     Finally, the use of the phrase “concentration applied to
 the dermal cells” in the wherein clause undermines
 UMass’s suggestion of a plain meaning and, more particu-
 larly, its proposal of what that meaning is. As indicated by
 the undisputed definition of M (molar concentration), a
 concentration is a number of particles (in moles) per unit
 of volume (liter). The skin-enhancement clause speaks of
 applying a “composition” to the skin where the composition
 “compris[es] a concentration of adenosine.” The claims re-
 fer to the composition being applied, not the
Case: 21-1969    Document: 50     Page: 10    Filed: 06/13/2022

 10             UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.

 “concentration,” and the reference is evidently to a number
 of particles per unit of volume of the composition that in-
 cludes the adenosine before putting it in contact with the
 skin. See Oral Arg. at 12:54–13:27. The wherein clause
 then speaks of a “concentration applied to the dermal cells.”
 This phrase naturally refers to a number of particles per
 unit of volume of the mixture of which the adenosine is a
 part before putting the mixture in contact with the dermal
 cells. But that apparent meaning, referring to a pre-appli-
 cation property, is contrary to UMass’s view of the mean-
 ing.
     UMass’s view is that the wherein clause refers to some-
 thing that has no existence before application—that it re-
 fers, instead, to a number of particles per unit of volume of
 the dermal layer, after the adenosine particles have suffused
 into the dermis and thus already come into contact with the
 dermal cells. Applying the district court’s construction,
 UMass’s infringement expert conducted cell-diffusion test-
 ing on L’Oréal’s accused products to trace adenosine as it
 seeps through the epidermis and dermis after it is topically
 applied to a skin sample. To determine the adenosine con-
 centration “applied to the dermal cells” (again, one part of
 the dermis), UMass’s expert calculated the concentration
 as moles of applied adenosine in the dermis over liters of
 dermis. See J.A. 12437. This methodology reveals UMass’s
 reliance on an interpretation that would call for a rewrite
 of the wherein clause (of claim 1 of the ’327 patent) to say
 something like “wherein the adenosine permeating to the
 dermal layer results in a concentration of adenosine in the
 dermal layer of 10-4 M to 10-7 M.” The need for a departure
 from the natural meaning confirms that UMass’s asserted
 meaning is not plain.
     For these reasons, we conclude that the claim language
 is not plain in the respect at issue.
Case: 21-1969     Document: 50      Page: 11       Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS     v. L’ORÉAL S.A.               11

                                B
     We next conclude that the specification and the prose-
 cution history show that the wherein clause should be read
 to refer to the concentration of adenosine in the composi-
 tion applied to the skin’s surface.
                                1
      The patents describe multiple embodiments that are
 within the claim scope as the “invention.” See ’327 patent,
 col. 1, line 35, through col. 2, line 34. More specifically, the
 specification states that “[t]he therapeutically effective
 amount of adenosine used in the above-described methods
 is preferably 10-3 M to 10-7 M, more preferably 10-3 M to
 10-6 M, and most preferably about 10-4 M,” id., col. 2, lines
 14–17, where the “above-described methods” include, for
 example, “topically administering a therapeutically effec-
 tive amount of adenosine . . . to a region of non-diseased
 skin of the mammal containing dermal cell,” id., col. 1, lines
 56–59; see also id., col. 1, lines 44–47; id., col. 1, lines 64–
 66; id., col. 2, lines 3–6. The patent further states that
 “[t]he invention also provides a composition including
 about 10-3 M to about 10-7 M adenosine and a therapeuti-
 cally effective amount of an angiogenesis factor.” Id., col.
 2, lines 30–34. None of these in-scope “invention” embodi-
 ments, or other references to specific numerical molar con-
 centration figures of 10-3 M to 10-7 M or the like, specify a
 measurement of concentration after seepage through the
 skin into the dermis—much less a measurement of concen-
 tration as an amount of adenosine per unit of volume of
 dermal cells. This is significant evidence that the wherein
 clause is best read to refer to the concentration of adeno-
 sine in the composition applied to the surface of the skin.
 See Phillips, 415 F.3d at 1316; VirnetX, Inc. v. Cisco Sys-
 tems, Inc., 767 F.3d 1308, 1318 (Fed. Cir. 2014); Netcraft
 Corp. v. eBay, Inc., 549 F.3d 1394, 1397–98 (Fed. Cir.
 2008).
Case: 21-1969    Document: 50      Page: 12    Filed: 06/13/2022

 12             UNIVERSITY OF MASSACHUSETTS     v. L’ORÉAL S.A.

      UMass points to other portions of the specification to
 support its contrary construction, but they do not show that
 the specification contemplates the concentration measure-
 ment UMass urges for the wherein clause. The specifica-
 tion does recognize that the epidermis is different from the
 dermis, which contains the dermal cells, see ’327 patent,
 col. 1, lines 19–25, and that when an adenosine-containing
 composition is applied topically to the surface of the epider-
 mis, not all the adenosine in the composition will penetrate
 to the dermis and dermal cells, see id., col. 5, lines 10–24;
 see also J.A. 2877. But the passages so recognizing do not
 imply that the invention includes measuring concentra-
 tions beneath the skin surface after topical application.
 UMass also cites the specification’s discussion of experi-
 ments in which particular dermal cells (fibroblasts) in la-
 boratory dishes were directly exposed to solutions having a
 concentration of adenosine in the recited concentration
 range. ’327 patent, col. 6, line 15, through col. 9, line 51.
 But UMass has not shown that, even in this context, the
 specification makes clear that the inventors contemplated
 measuring the adenosine concentration after exposure to
 the cells, rather than in a solution before application to the
 cells. See L’Oréal Response Br. 49–51 (characterizing the
 experiments as using pre-application measurements);
 UMass Reply Br. 25–27 (not contesting that characteriza-
 tion). And, in any event, the passages on the experiments
 certainly do not make clear any such contemplation in the
 context of a topical skin application covered by the claims
 at issue.
                               2
     Even more strongly than the specification, the prosecu-
 tion histories of the patents in question resolve the ambi-
 guity surrounding the meaning of “the adenosine
 concentration applied to the dermal cells” in the wherein
 clause. The starting point is that the predecessor claim of
 independent claim 1 of the ’327 patent was identical to cur-
 rent claim 1, except that it lacked the current wherein
Case: 21-1969    Document: 50      Page: 13       Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.               13

 clause. J.A. 2684. A separate dependent claim, however,
 claimed the method of the independent claim with the
 added requirement, “wherein the adenosine concentration
 is 10-4 M to 10-6 M.” J.A. 2684. Those claims made no men-
 tion of application to “dermal cells” and thus seemingly re-
 ferred only to adenosine concentrations applied to the skin.
      Then, to overcome a prior-art rejection, applicants im-
 ported the dependent claim’s wherein clause into the inde-
 pendent claim, but altered its wording so that it now read
 “wherein the adenosine concentration applied to the der-
 mal cells is 10-4 M to 10-6 M.” J.A. 2701. Importantly, in
 describing the amendment to the examiner in the office-
 action response, applicants implied that this new wording
 changed nothing about where the concentration was to be
 measured. Applicants remarked: “This amendment would
 add no new matter, as it merely includes a range of concen-
 trations of adenosine recited in dependent claims.” J.A.
 2702 (emphasis added) (also stating “all [claims] are based
 on the application of certain concentrations of adenosine to
 the skin to achieve certain results”); see also J.A. 2762 (sim-
 ilar description in ’513 prosecution history). In fact, in the
 same filing, applicants went on to distinguish two prior-art
 references in which concentrations are measured before ap-
 plication to the skin, and they did so at least in part by di-
 rectly comparing the prior-art adenosine composition
 concentrations to the claims’ adenosine concentration re-
 cited in the wherein clause, with no suggestion of a differ-
 ence in location of concentration measurement. J.A. 2703–
 07; J.A. 2722–24. Based on those representations, the ex-
 aminer eventually allowed the claims, commenting that
 the “[i]nstant claims are directed to a method of enhancing
 the condition of unbroken skin . . . where the method com-
 prises administering adenosine at a concentration of 10-4 M
 to 10-7 M, to the skin.” J.A. 2727 (emphasis added). And
 the next year, the examiner made the same statement in
 allowing the application that issued as the ’513 patent.
 J.A. 2769.
Case: 21-1969    Document: 50      Page: 14    Filed: 06/13/2022

 14             UNIVERSITY OF MASSACHUSETTS     v. L’ORÉAL S.A.

     We hold that this prosecution history requires that the
 wherein clause’s reference to the recited concentrations be-
 ing “applied to the dermal cells” be read as referring to con-
 centrations of the composition applied to the skin’s surface.
 The amendments and comments clearly convey that
 UMass was continuing the pre-amendment reliance on the
 concentration in the composition before application to the
 skin, rather than introducing a materially different, unex-
 plained notion of concentration, no longer assessed before
 contact with the object of application. UMass’s proposed
 construction now cannot fairly be squared with the under-
 standing that both it and the examiner expressed during
 prosecution, and on which skilled artisans are entitled to
 rely.
      UMass makes various counterarguments concerning
 the prosecution history, but all are unavailing. As an ini-
 tial, legal matter, we reiterate that this is not a case where
 the prosecution history must meet the standard of clear
 and unmistakable disclaimer for overcoming an otherwise-
 plain meaning, contrary to UMass, the Board, and the dis-
 trict court’s framings. See UMass Reply Br. 27; J.A. 2808–
 10; J.A. 3721 (Hearing Tr. at 58:4–7). We need not decide
 whether that standard is met here. Because the meaning
 of the relevant claim language is not plain, but rather am-
 biguous for the reasons described in Section II.A, we can
 look to the prosecution history to “inform[] the meaning of
 the disputed claim phrase and address[] an ambiguity oth-
 erwise left unresolved.” Personalized Media Communica-
 tions, 952 F.3d at 1345; see also SoundView Innovations,
 LLC v. Hulu, LLC, 33 F.4th 1326, 1332–35 (Fed. Cir. 2022).
     Additionally, UMass’s two factual arguments concern-
 ing the prosecution history are unpersuasive. First, UMass
 contends that applicants’ distinguishing of the prior-art
 references should not be given weight because applicants
 did not do so “solely” on the basis of adenosine concentra-
 tion. UMass Reply Br. 29. This is unsupported by the rec-
 ord. Concerning one cited reference, German patent
Case: 21-1969    Document: 50     Page: 15        Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.               15

 application DE 19545107, see J.A. 2709–20, applicants
 compared DE ’107’s adenosine composition concentration
 to the claims’ recited concentration range and argued that,
 although DE ’107 disclosed a concentration of adenosine
 within the recited range, it incorrectly taught that this
 level of adenosine would increase cell proliferation, J.A.
 2704; J.A. 2722–24. 1 Similarly, concerning another cited
 reference, Hartzshtark, see J.A. 2917–18, applicants again
 compared Hartzshtark’s adenosine composition concentra-
 tion to the claims’ recited concentration range, this time
 distinguishing Hartzshtark on the basis of this limitation,
 J.A. 2705–06; see also J.A. 2723. That applicants at least
 twice compared the claims’ adenosine concentration in the
 wherein clause to prior-art adenosine composition concen-
 trations—whether to distinguish the claims’ concentration
 range for Hartzhtark or some other aspect of the claims for
 DE ’107—strongly signals that the wherein clause requires
 that the recited concentrations are measured as amounts
 per volume of the composition applied to the skin’s surface.
 Cf. Amgen Inc. v. Coherus BioSciences, Inc., 931 F.3d 1154,
 1159–60 (Fed. Cir. 2019); Saffran v. Johnson & Johnson,
 712 F.3d 549, 559 (Fed. Cir. 2013).
     Second, UMass seeks to dilute applicants’ prior state-
 ments and arguments during prosecution by pointing to
 the voluntary comments applicants made in response to
 the examiner’s reasons for allowance in the ’327 prosecu-
 tion history. See Salazar v. Procter & Gamble Co., 414 F.3d
 1342, 1345 (Fed. Cir. 2005). Specifically, after noting that
 they were not conceding that the examiner’s reason for al-
 lowance was the only reason the claims were allowable,

     1   In arguing that the amount of adenosine recited in
 DE ’107 does not increase dermal-cell proliferation, appli-
 cants submitted results from tests in which adenosine was
 applied directly to fibroblasts at concentrations of 10-4 M
 and 10-5 M. J.A. 2704; J.A. 2723.
Case: 21-1969    Document: 50     Page: 16    Filed: 06/13/2022

 16             UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.

 applicants further “note[d] that the claimed concentration
 of adenosine is applied to the dermal cells.” J.A. 2729. But
 that statement merely recited the ambiguous claim lan-
 guage; it did not communicate a disagreement with the ex-
 aminer’s clear statement of what that language meant.
 UMass did not clarify the sense in which it was using the
 term “apply” (which, again, can mean apply directly or ap-
 ply indirectly), let alone explain the measurement method-
 ology UMass now says is required (using the dermal layer
 as the volume). Tellingly, when the examiner made the
 same statement in allowing the application that issued as
 the ’513 patent, UMass, while submitting a one-sentence
 comment on the statement of reasons for allowance, made
 no reference to the “applied to the dermal cells” language.
 J.A. 2771. For these reasons, UMass’s bare statement
 made after allowance in the ’327 prosecution history does
 not provide a sufficient reason to adopt a different con-
 struction from the one clearly indicated by the rest of the
 prosecution history (and specification). See Biogen, Inc. v.
 Berlex Laboratories, Inc., 318 F.3d 1132, 1138–39 (Fed. Cir.
 2003).
                              C
     As a result of our new construction, the district court’s
 subsequent indefiniteness ruling must be vacated, and we
 remand for the district court to conduct any further pro-
 ceedings that are necessary. Although L’Oréal proposes
 that, if we reverse the claim construction of the wherein
 clause, we could directly enter a judgment of non-infringe-
 ment, we leave it to the district court to determine how to
 proceed under the new construction. See L’Oréal Response
 Br. 45–46 & n.24 (contending that UMass conceded non-
 infringement); UMass Reply Br. 21 (disputing concession);
 Oral Arg. at 18:45–19:10, 48:13–49:16 (also discussing ex-
 istence of invalidity counterclaims).
Case: 21-1969     Document: 50        Page: 17      Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS      v. L’ORÉAL S.A.               17

                                III
     UMass also challenges the district court’s personal-ju-
 risdiction determinations. See Personal Jurisdiction Re-
 port and Recommendation at 17–26; Personal Jurisdiction
 Order at 1–4. Because we find that at the very least juris-
 dictional discovery was appropriate, we vacate and remand
 to the district court, without reaching the question of
 whether UMass made a sufficient prima facie showing that
 L’Oréal S.A. was subject to personal jurisdiction based on
 the complaint and evidence submitted at the time of the
 Rule 12(b)(2) motion. See Autogenomics, Inc. v. Oxford
 Gene Technology Ltd., 566 F.3d 1012, 1016–17 (Fed. Cir.
 2009).
      Personal-jurisdiction analysis for patent-infringement
 claims is governed by Federal Circuit law. See Synthes
 (U.S.A.) v. G.M. Do Reis Jr. Ind. Com. de Equip. Medico,
 563 F.3d 1285, 1293 (Fed. Cir. 2009); Electronics for Imag-
 ing, Inc. v. Coyle, 340 F.3d 1344, 1348 (Fed. Cir. 2003). A
 denial of jurisdictional discovery, however, is reviewed for
 abuse of discretion, applying the law of the regional circuit.
 Autogenomics, 566 F.3d at 1021–22. In the Third Circuit,
 “[i]f the plaintiff presents factual allegations that suggest
 with reasonable particularity the possible existence of the
 requisite contacts . . . , the plaintiff’s right to conduct juris-
 dictional discovery should be sustained.” Eurofins Pharma
 US Holdings v. BioAlliance Pharma SA, 623 F.3d 147, 157
 (3d Cir. 2010) (cleaned up and emphasis added); see also
 Compagnie Des Bauxites de Guinee v. L’Union Atlantique
 S.A. d’Assurances, 723 F.2d 357, 362 (3d Cir. 1983) (“A
 plaintiff who is a total stranger to a corporation should not
 be required, unless he has been undiligent, to try such an
 issue on affidavits without the benefit of full discovery.” (ci-
 tation omitted)). In other words, jurisdictional discovery
 should be allowed unless plaintiff is attempting to “under-
 take a fishing expedition based only upon bare allegations”
 or a claim is “clearly frivolous.” Eurofins, 623 F.3d at 157;
Case: 21-1969    Document: 50      Page: 18     Filed: 06/13/2022

 18              UNIVERSITY OF MASSACHUSETTS     v. L’ORÉAL S.A.

 Toys “R” Us, Inc. v. Step Two, S.A., 318 F.3d 446, 456 (3d
 Cir. 2003) (citation omitted).
      Here, the district court abused its discretion in not al-
 lowing jurisdictional discovery on the record before it. In
 front of the magistrate judge, UMass made more than
 clearly frivolous, bare allegations that L’Oréal S.A. was
 subject to personal jurisdiction, either because L’Oréal S.A.
 introduced the accused products into the stream of com-
 merce or because L’Oréal USA operated as L’Oréal S.A.’s
 agent in certain potentially relevant respects. See Plain-
 tiffs’ Memorandum of Law in Opposition to Defendant
 L’Oréal S.A.’s Motion to Dismiss at 1–17, University of
 Massachusetts v. L’Oreal S.A., No. 1:17-cv-00868 (D. Del.
 Dec. 8, 2017), ECF No. 27. For example, as potentially rel-
 evant to both theories, UMass put forward evidence but-
 tressing the possibility that L’Oréal S.A. researched and
 developed the addition of adenosine to skin-care products,
 J.A. 263–69; J.A. 1070; J.A. 1073–77, and L’Oréal S.A.’s
 own submitted declaration indicated that L’Oréal S.A. may
 have licensed that technology to L’Oréal USA, J.A. 553–54
 (Rabinowitz Decl. ¶ 6) (“From time to time, L’Oréal S.A.
 and L’Oréal USA engage in the sale of goods or services
 between the two companies.”). For its part, L’Oréal S.A.
 did not specifically deny allegations that it developed and
 licensed the relevant technology to L’Oréal USA, stating
 only that “L’Oréal S.A. does not directly develop, sell, mar-
 ket, or advertise to consumers in Delaware any of the prod-
 ucts at issue in this action,” without making it clear what
 it meant by “directly develop.” J.A. 553–54 (Rabinowitz
 Decl. ¶ 6). 2

      2  UMass may not have objected to the magistrate
 judge’s finding that UMass did not, based on the evidence
 in front of the district court at the time of the Rule 12(b)(2)
 motion, sufficiently show personal jurisdiction based on a
 stream-of-commerce theory. See J.A. 1251–55. But, on the
Case: 21-1969    Document: 50      Page: 19       Filed: 06/13/2022

 UNIVERSITY OF MASSACHUSETTS    v. L’ORÉAL S.A.               19

     Because this evidence raises the possibility that discov-
 ery might have uncovered the requisite contacts under our
 precedent, see, e.g., Nuance Communications, Inc. v. Abbyy
 Software House, 626 F.3d 1222, 1233–34 (Fed. Cir. 2010);
 Celgard, LLC v. SK Innovation Co., 792 F.3d 1373, 1379–
 82 (Fed. Cir. 2015), we vacate the jurisdictional determina-
 tions. UMass is entitled to jurisdictional discovery before
 any jurisdictional determination, if one remains necessary,
 is made.
                              IV
     For the foregoing reasons, we reverse the district
 court’s claim construction of the wherein clause and vacate
 the court’s subsequent summary-judgment determination.
 We also vacate the district court’s personal-jurisdiction de-
 terminations. And on both issues, we remand for further
 proceedings consistent with this opinion.
     The parties shall bear their own costs.
    REVERSED IN PART, VACATED IN PART, AND
                  REMANDED

 issue of discovery, UMass did more generally object. J.A.
 1255 (“At the very least, Plaintiff’s’ argument that L’Oréal
 S.A. designs and develops the Accused Adenosine Products
 is not ‘clearly frivolous,’ given the extensive supporting
 public evidence, and Plaintiffs should be permitted to take
 jurisdictional discovery.” (quoting Toys “R” Us, 318 F.3d at
 456)).