Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd.

133 F.4th 1359

• Court: Court of Appeals for the Federal Circuit
• Decided: April 8, 2025
• Docket: 23-1977
• Status: Published

Opinion

Case: 23-1977 Document: 38 Page: 1 Filed: 04/08/2025

United States Court of Appeals for the Federal Circuit ______________________

AZURITY PHARMACEUTICALS, INC., Plaintiff-Appellant

v.

ALKEM LABORATORIES LTD., Defendant-Appellee ______________________

2023-1977 ______________________

Appeal from the United States District Court for the District of Delaware in No. 1:20-cv-01094-MSG, Chief Judge Mitchell S. Goldberg. ______________________

Decided: April 8, 2025 ______________________

TUNG ON KONG, Wilson, Sonsini, Goodrich & Rosati, PC, San Francisco, CA, argued for plaintiff-appellant. Also represented by WENDY L. DEVINE; KELSEY CURTIS, RICHARD TORCZON, Washington, DC.

ALAN HENRY POLLACK, Windels Marx Lane & Mitten- dorf, LLP, Madison, NJ, argued for defendant-appellee. Also represented by KIERSTEN AMANDA FOWLER, JOSHUA I. MILLER. ______________________ Case: 23-1977 Document: 38 Page: 2 Filed: 04/08/2025

Before MOORE, Chief Judge, CHEN, Circuit Judge, and MURPHY, District Judge. 1 MURPHY, District Judge. This appeal arises from a suit under the Hatch-Wax- man Act. Azurity Pharmaceuticals, Inc. (“Azurity”) brought suit against Alkem Laboratories Ltd. (“Alkem”) for infringement of claims 5, 7, 8, and 9 of U.S. Patent No. 10,959,948 (“the ’948 patent”) following Alkem’s submis- sion of an Abbreviated New Drug Application (“ANDA”). After a two-day bench trial, the court found that Alkem’s ANDA did not infringe any of the asserted claims of the ’948 patent. Azurity Pharms., Inc. v. Alkem Lab’ys, Ltd., 671 F. Supp. 3d 489 (D. Del. 2023). Because the district court correctly found that Azurity disclaimed any presence of propylene glycol in the prosecution history of the ’948 patent, Alkem’s ANDA product contains propylene glycol, and a stipulation entered by the parties during discovery does not preclude Alkem’s disclaimer argument, we affirm. BACKGROUND Azurity’s ’948 patent is directed to non-sterile drinka- ble liquid formulations containing the antibiotic vancomy- cin and methods for using those formulations to treat Clostridium difficile infection. ’948 patent, Abstract; id. at col. 1, ll. 21–25. Drinkable liquid drugs are particularly useful for treating pediatric and geriatric populations be- cause they present a lower choking risk than capsules and, unlike injections, do not require sterilization. Id. at col. 5, ll. 31–55; id. at col. 6, ll. 1–17. Claim 5 of the ’948 patent is representative and is re- produced below:

1 Honorable John F. Murphy, District Judge, United States District Court for the Eastern District of Pennsylva- nia, sitting by designation. Case: 23-1977 Document: 38 Page: 3 Filed: 04/08/2025

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5. A non-sterile stable liquid formulation formu- lated for oral administration, consisting of: a buffering agent, wherein the buffering agent is selected from the group consisting of citric acid, sodium citrate, sodium tar- tarate, sodium acetate, sodium carbonate, sodium polyphosphate, potassium poly- phosphate, sodium pyrophosphate, potas- sium pyrophosphate, disodium hydrogen phosphate, trisodium phosphate, tripotas- sium phosphate, sodium acetate, potas- sium metaphosphate, magnesium oxide, magnesium carbonate, magnesium silicate, calcium acetate, calcium glycerophosphate, calcium chloride, calcium hydroxide, cal- cium lactate, calcium carbonate, calcium bicarbonate, and calcium salts, water, a sweetener, a preservative, wherein the preservative is selected from the group consisting of so- dium benzoate, parabens, benzoic acid, po- tassium sorbate, benzyl alcohol or salts thereof, vancomycin hydrochloride, and flavoring agent, wherein the non-sterile stable liquid formulation is homogenous and stable for at least 1 week at am- bient and refrigerated temperature and has a pH of 2.5–4.5. Id. at col. 46, ll. 49–67, col. 47, ll. 1–3 (emphases added). The application for the ’948 patent, U.S. Patent Appli- cation No. 16/941,400 (“the ’400 application”) was allowed Case: 23-1977 Document: 38 Page: 4 Filed: 04/08/2025

without rejection. Azurity, 671 F. Supp. 3d at 502. But that application was a continuation of U.S. Patent Applica- tion No. 15/126,059 (“the ’059 application”), which had been rejected several times by the examiner over a prior art ref- erence known as Palepu, U.S. Patent Application Publica- tion 2016/0101147. Azurity, 671 F. Supp. 3d at 497–502. Palepu discloses an intravenously administered liquid for- mulation containing vancomycin used to treat Clostridium difficile with “a polar solvent including propylene glycol.” J.A. 3606–07. The district court determined that, through amend- ments and arguments made in the ’059 application distin- guishing Palepu, Azurity “clearly and unmistakably” disclaimed propylene glycol from the invention claimed in the ’948 patent. Azurity, 671 F. Supp. 3d at 509–10. The district court found that Alkem’s ANDA product undisput- edly contains propylene glycol, and accordingly ruled that Alkem’s ANDA product did not infringe the ’948 patent be- cause the asserted claims used the closed “consisting of” transition. Id. at 510–12. Azurity argued that a stipulation made during discov- ery overcame any disclaimer arising from the “flavoring agent” claim term. Id. at 511. The parties had stipulated that “[s]uitable flavoring agents for use in the Asserted Claims include flavoring agents with or without propylene glycol.” Id. Azurity interpreted the stipulation to mean that products with flavoring agents that include propylene glycol could infringe the ’948 patent regardless of the “con- sisting of” transition and any purported disclaimer. The district court found that Azurity’s interpretation of the stipulation was “unpersuasive,” and that the disclaimer of propylene glycol was still dispositive. Id. Azurity appeals. We have jurisdiction under 28 U.S.C. § 1295(a)(1). Case: 23-1977 Document: 38 Page: 5 Filed: 04/08/2025

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DISCUSSION I We review a judgment following a district court bench trial for legal error or clearly erroneous factual findings. Genentech, Inc. v. Sandoz Inc., 55 F.4th 1368, 1375 (Fed. Cir. 2022). “Infringement . . . is a question of fact.” Id. at 1375–76. “Under the clear-error standard, we defer to the district court’s findings in the absence of a definite and firm conviction that a mistake has been made.” Par Pharm., Inc. v. Eagle Pharms., Inc., 44 F.4th 1379, 1383 (Fed. Cir. 2022) (quotations omitted). Claim construction is reviewed de novo, and any under- lying factual determinations are reviewed for clear error. Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 326– 27 (2015). An application of prosecution disclaimer is re- viewed de novo. Genuine Enabling Tech. LLC v. Nintendo Co., 29 F.4th 1365, 1372 (Fed. Cir. 2022). “A stipulation of fact that is fairly entered into is con- trolling on the parties and the court is generally bound to enforce it.” Ring & Pinion Serv. Inc. v. ARB Corp., 743 F.3d 831, 836 (Fed. Cir. 2014). When “[r]eview[ing] . . . the dis- trict court’s interpretation of the parties’ pre-trial stipula- tions . . . this court reviews underlying factual findings for clear error and reviews the ultimate interpretation of the stipulation de novo.” Akamai Techs., Inc. v. Limelight Net- works, Inc., 805 F.3d 1368, 1374 (Fed. Cir. 2015). II We will leave aside the issues raised by Azurity related to the stipulation for a later section in this opinion. In- stead, we first address Azurity’s argument related to dis- claimer. And we begin by recapitulating the portions of the prosecution history relevant to the ’948 patent. Case: 23-1977 Document: 38 Page: 6 Filed: 04/08/2025

A The ’948 patent is part of a larger patent family that includes U.S. Patent Nos. 10,959,946, 10,959,947, and 10,959,949. The following discussion will explain how Az- urity’s claims directed to vancomycin liquid formulations evolved during the prosecution that led to ’948 patent. The earliest claims, filed in the ’059 application, used the open- ended transition “comprising” to specify the formulation: “A non-sterile stable liquid formulation comprising a com- pounded solution of vancomycin . . . .” Azurity, 671 F. Supp. 3d at 498. The examiner rejected these claims over prior art including Palepu. In early 2019, Azurity proposed several draft amend- ments and new claims in preparation for an interview with the examiner. Of relevance here, some included the follow- ing negative limitations: “wherein the oral liquid solution does not comprise a propylene glycol,” “wherein the liquid solution does not comprise a suspending agent,” and “wherein the liquid solution does not comprise a propylene glycol.” J.A. 2425–27. In the interview summary, the ex- aminer explained that the negative claim limitations ex- cluding propylene glycol were insufficient to overcome the rejection because Palepu also disclosed polyethylene glycol. J.A. 2429. The examiner also remarked that the exclusion of suspending agents did not address Palepu’s disclosure of propylene glycol because Palepu’s glycols were said to be solvents, not suspending agents. Id. The examiner sug- gested that Azurity “could amend using consisting of lan- guage.” Id. Shortly after, Azurity formally responded, amending then claims 16 and 20 to include a negative limitation ex- cluding propylene glycol. J.A. 2441–42. And for then claims 24 and 31, Azurity introduced the close-ended tran- sition phrase “consisting of.” J.A. 2442–43. Specifically, those two claims recited “[a] liquid solution comprising a carrier consisting of” certain ingredients—propylene glycol Case: 23-1977 Document: 38 Page: 7 Filed: 04/08/2025

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not among them. Id. In the accompanying remarks, Azur- ity argued that Palepu’s compositions include “a polar sol- vent comprising propylene glycol, polyethylene glycol, or mixtures thereof” and that “[t]he absence of propylene gly- col and polyethylene glycol in the claimed invention [of then claim 20], in part, distinguish it from [Palepu].” J.A. 2435. Along with that response, Azurity submitted a declara- tion by Dr. Steven Dinh, Azurity’s Executive Vice President and Chief Scientific Officer. Dr. Dinh averred that “[a]s shown in the [’059] Application, the diluent and the com- pounded solutions do not have propylene glycol or polyeth- ylene glycol, both of which were noted as important components in Palepu’s compositions.” J.A. 2448. In the next office action, the examiner rejected the amended claims with negative limitations because there was no description for a solution that “does not comprise a propylene glycol or a suspending agent.” J.A. 2467. The examiner also objected to Azurity’s separation of vancomy- cin from the liquid solution containing the other ingredi- ents (termed the “carrier” in these claims) because the specification “does not provide written description for a separate carrier consisting of the [other] ingredients.” Id. (emphasis removed). And the examiner rejected the claim language that used “comprising” and “consisting of” in tan- dem because it was unclear “if other components can be present with the solution or not.” J.A. 2469. In response, Azurity amended its claims again, remov- ing the putatively unsupported negative limitations and adding “consisting of” or “consists of” preambles to the claims. J.A. 2519–21. Turning to the prior art, Azurity argued that “[t]he absence of propylene glycol and polyeth- ylene glycol in the claimed invention, in part, distinguish it from [Palepu],” and further stated that “the compositions of Palepu do not fall within the scope of the claimed inven- tion. The claimed invention does not include the polar Case: 23-1977 Document: 38 Page: 8 Filed: 04/08/2025

solvents or lactic acid of Palepu.” J.A. 2527–28. Azurity reiterated similar reasoning for the remaining claims, re- lying on the closed nature of the amended claims and Papelu’s inclusion of other ingredients such as propylene glycol. J.A. 2528–31. Eventually, the examiner allowed the relevant claims of the ’059 application. In the accompanying reasons for allowance, the examiner explained that Palepu “teaches a non-sterile stable liquid formulation having vancomycin hydrochloride together with either propylene glycol or pol- yethylene glycol in the liquid formulation. The instant claims exclude the presence of propylene glycol or polyeth- ylene glycol in view of the consisting of language, and thus overcome the teachings of Palepu which requires the pro- pylene glycol or polyethylene glycol to be present with the vancomycin hydrochloride.” J.A. 2570. After that al- lowance, Azurity filed the ’400 application as a continua- tion of the ’059 application. The examiner allowed those claims without rejection, and they issued in the ’948 pa- tent. After Alkem submitted its Paragraph IV letter related to this lawsuit, on October 13, 2020—in another patent ap- plication in the same family also claiming priority to the ’059 application, U.S. Patent Application No. 16/892,421 (“the ’421 application”)—Azurity made the following state- ment in the introduction of a response to an office action: “For the record, Applicant did not disclaim propylene glycol when submitting the arguments in U.S. 15/126059, and re- serves the right to claim propylene glycol in the instant and future cases in this patent family.” Azurity, 671 F. Supp. 3d at 503; J.A. 2808. The examiner allowed the claims at issue there, but did not respond to Azurity’s statement. The examiner stated that the claims—which also used the “consisting of” transition—were allowed because “[n]one of the prior art teaches or suggests a composition consisting of ingredients a-f as claimed.” J.A. 2822. The “ingredients a-f” were citric acid, water, a sweetener, sodium benzoate, Case: 23-1977 Document: 38 Page: 9 Filed: 04/08/2025

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20–60 mg/ml vancomycin hydrochloride, and flavoring agent. J.A. 2821. The examiner also stated that “Palepu’s formulations require propylene glycol present as the polar solvent with lactic acid.” Id. B With a full appreciation for the relevant prosecution history, we now consider whether the district court cor- rectly held that Azurity clearly and unmistakably dis- claimed propylene glycol. We hold that it did, and that the disclaimer of propylene glycol applies to all claims of the ’948 patent. Azurity argues that the district court’s interpretation of the prosecution history is overbroad. Azurity views the prosecution history as ambiguous and, even if there were a disclaimer, Azurity argues that it excludes propylene glycol only as a carrier and does not reach the claim term “flavor- ing agent.” Alkem asks us to affirm the district court’s find- ing that Azurity disclaimed any inclusion of propylene glycol. One of two exceptions to the general rule of claim con- struction is “when the patentee disavows the full scope of a claim term either in the specification or during prosecu- tion.” Thorner v. Sony Comput. Ent. Am. LLC, 669 F.3d 1362, 1365 (Fed. Cir. 2012). “A patentee may, through a clear and unmistakable disavowal in the prosecution his- tory, surrender certain claim scope to which he would oth- erwise have an exclusive right by virtue of the claim language.” Data Engine Techs. LLC v. Google LLC, 10 F.4th 1375, 1382 (Fed. Cir. 2021) (quoting Vita-Mix Corp. v. Basic Holding, Inc., 581 F.3d 1317, 1324 (Fed. Cir. 2009)). “Any explanation, elaboration, or qualification pre- sented by the inventor during patent examination is rele- vant, for the role of claim construction is to capture the scope of the actual invention that is disclosed, described, and patented.” TriVascular, Inc. v. Samuels, 812 F.3d 1056, 1063 (Fed. Cir. 2016) (quotations omitted). Holding Case: 23-1977 Document: 38 Page: 10 Filed: 04/08/2025

patentees to their definitive statements made during pros- ecution protects the public and promotes the notice func- tion of intrinsic evidence. Data Engine Techs., 10 F.4th at 1383. Statements that clearly and unmistakably disavow claim scope to one skilled in the art are binding, “even if [the patentee] said more than needed to overcome a prior art rejection.” Id. Courts must take care, however, to in- terpret purported disavowals in the context of the prosecu- tion history as a whole. Ecolab, Inc. v. FMC Corp., 569 F.3d 1335, 1342 (Fed. Cir. 2009), amended on reh’g in part, 366 F. App’x 154 (Fed. Cir. 2009). “The party seeking to invoke prosecution history disclaimer bears the burden of proving the existence of a ‘clear and unmistakable’ disclaimer that would have been evident to one skilled in the art.” Tri- Vascular, 812 F.3d at 1063–64. Here, Alkem amply met its burden by identifying Az- urity’s clear and unmistakable statements in the prosecu- tion history of the ’948 patent disclaiming the presence of any propylene glycol in the claimed invention. To reach our conclusion about the scope of the ’948 pa- tent, we focus on the relevant prosecution history in the ’400 application and its parent ’059 application. Azurity contends that its remarks made in the ’421 application are also relevant for determining the scope of the claims of the ’948 patent. This is incorrect. It is true that statements in the prosecution histories of patents descended from a com- mon ancestor application may be relevant for interpretat- ing the claims in the related patents. But our decisions have focused on how such statements have been relevant to later issued patents. See, e.g., Elkay Mfg. Co. v. Ebco Mfg. Co., 192 F.3d 973, 980 (Fed. Cir. 1999) (discussing the relevance of the prosecution histories of two related pa- tents where the application for the subsequently issued pa- tent was filed as a continuation of the earlier issued patent after the first patent was allowed); Biovail Corp. Int’l v. An- drx Pharms., Inc., 239 F.3d 1297, 1301 (Fed. Cir. 2001) (same); Gemalto S.A. v. HTC Corp., 754 F.3d 1364, 1371 Case: 23-1977 Document: 38 Page: 11 Filed: 04/08/2025

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(Fed. Cir. 2014) (same); Microsoft Corp. v. Multi-Tech Sys., Inc., 357 F.3d 1340, 1349–50 (Fed. Cir. 2004) (applying dis- claimer in one application to related, later-issued patents). Here, Azurity prosecuted the ’421 application in paral- lel with the ’400 application, and the ’421 application was a continuation of yet another application (U.S. Patent Ap- plication No. 15/791,717) not a part of the direct line of ap- plications that led to the ’948 patent; the ’421 application was in effect the ’400 application’s grand-nephew. Azurity, 671 F. Supp. 3d at 503. And Azurity made its “for the rec- ord” statement in the ’421 application after the examiner had allowed the claims of the ’400 application. Judging these circumstances through the lens of public notice, Az- urity’s unilateral and belated statement carries no weight. Turning to the more pertinent ’059 application, there, the examiner repeatedly cited Palepu as prior art. And at every opportunity, Azurity clearly and unmistakably dis- tinguished its invention from Palepu by asserting that the claimed formulations did not contain propylene glycol. See supra, § II.A. The evolution of the two independent claims that emerged from the ’059 application, claims 20 and 24, illus- trates the point. In a first amendment, Azurity added the negative claim limitation “wherein the [] solution does not comprise a suspending agent” to both claims. J.A. 2425– 26. After rejection, in a second amendment, Azurity added the negative limitation “wherein the compounded solution does not comprise propylene glycol” to claim 20 and added “comprising a carrier consisting of” to the preamble of claim 24. J.A. 2442 (emphasis added). And in accompany- ing remarks about claim 20, Azurity stated that “[t]he ab- sence of propylene glycol and polyethylene glycol in the claimed invention, in part, distinguish it from [Palepu].” J.A. 2435 (emphases added). And even the declarant, Dr. Dinh, reiterated that “[a]s shown in the Application, the Case: 23-1977 Document: 38 Page: 12 Filed: 04/08/2025

diluent and the compounded solutions do not have propyl- ene glycol.” J.A. 2448 (emphasis added). At the examiner’s suggestion and after another rejec- tion, Azurity added “consisting of” to the preambles of claims 20 and 24. The “consisting of” transition is closed. With little exception, it limits the claim’s scope to the re- cited components. Norian Corp. v. Stryker Corp., 363 F.3d 1321, 1331 (Fed. Cir. 2004) (“‘Consisting of’ is a term of pa- tent convention meaning that the claimed invention con- tains only what is expressly set forth in the claim.”); AFG Indus., Inc. v. Cardinal IG Co., 239 F.3d 1239, 1245 (Fed. Cir. 2001) (“‘[C]losed’ transition phrases such as ‘consisting of’ are understood to exclude any elements, steps, or ingre- dients not specified in the claim.”). The prosecution history leaves no room to doubt that Azurity adopted the “consisting of” transition specifically to narrow the claims and overcome Palepu and its disclo- sure of propylene glycol. Azurity confirmed as much in its remarks, arguing for claim 20 that “Palepu teaches that its polar solvents (e.g. propylene glycol) and lactic acid (or the lactate molecule used in some embodiments) confer its com- positions with long-term stability. The claimed invention is an oral vancomycin formulation that . . . does not include the polar solvents or lactic acid of Palepu.” J.A. 2530 (em- phases added). And for claim 24, Azurity stated that “the liquid solution now consists of the ingredients (a)-(f) and vancomycin hydrochloride.” J.A. 2531 (emphasis added). The examiner’s reasons for allowance agree with and incor- porate Azurity’s arguments: “[t]he instant claims exclude the presence of propylene glycol or polyethylene glycol in view of the consisting of language, and thus overcome the teachings of Palepu which requires the propylene glycol or polyethylene glycol to be present with the vancomycin hy- drochloride.” J.A. 2570 (emphases added). With immaterial changes, those versions of claims 20 and 24 from the ’059 application ultimately became the two Case: 23-1977 Document: 38 Page: 13 Filed: 04/08/2025

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independent claims in the ’948 patent. J.A. 2562. Im- portantly, the claims of the ’400 application included the same “consisting of” preambles added during the prosecu- tion of the ’059 application. Azurity’s amendments and ar- guments made while prosecuting the ’059 application apply directly to the ’400 application and the ’948 patent that fol- lowed because the ’400 application is a continuation of the ’059 application. Elkay Mfg. Co., 192 F.3d at 980 (“When multiple patents derive from the same initial application, the prosecution history regarding a claim limitation in any patent that has issued applies with equal force to subse- quently issued patents that contain the same claim limita- tion.”). Azurity’s alternative argument that the disclaimer of propylene glycol applies only to the carrier and not to the flavoring agent is unconvincing. The record reflects that Azurity tried multiple routes to satisfy the examiner that unlike Palepu, its claimed invention lacked propylene gly- col. The examiner insisted on clarity, and Azurity acqui- esced by abandoning the “carrier” distinction and adopting the “consisting of” transition. And the examiner confirmed that the claims were allowed because they “exclude the presence of propylene glycol.” J.A. 2570. Azurity argues that in Palepu, propylene glycol functions only as a carrier. That may be true, but what matters most is the broad lan- guage that Azurity used to distinguish Palepu. Just as the echo matches the shout, Azurity’s repeated, sweeping statements—endorsed by the examiner—return an equally sweeping disclaimer. See Tech. Props. Ltd. LLC v. Huawei Techs. Co., 849 F.3d 1349, 1359 (Fed. Cir. 2017) (“[T]he scope of surrender is not limited to what is absolutely nec- essary to avoid a prior art reference; patentees may surren- der more than necessary.”). Based on the totality of the relevant prosecution his- tory, we conclude that Azurity’s disclaimer of propylene glycol in the claims of the ’948 patent was clear, unambig- uous, and complete. Case: 23-1977 Document: 38 Page: 14 Filed: 04/08/2025

III We next address Azurity’s argument that one of the parties’ pretrial stipulations precludes any application of the disclaimer. Before trial, the parties prepared a list of at least 143 undisputed facts that did not require proof at trial. The very last stipulation in this section is the critical one that Azurity relies on here: “Suitable flavoring agents for use in the Asserted Claims include flavoring agents with or with- out propylene glycol.” J.A. 1773. According to Azurity, the stipulation means that Alkem surrendered its disclaimer argument at least with respect to the claimed “flavoring agent.” Put another way—and consistent with how the dis- trict court understood Azurity’s interpretation—“[s]uitable flavoring agents for use in the Asserted Claims” means “in- fringing flavoring agents.” Azurity, 671 F. Supp. 3d at 511 (emphasis added). Alkem disagrees, arguing when the stipulation is understood in the context of its origin, it merely confirms that in this field, the relevant flavoring agents need not have propylene glycol. For several reasons, we agree with Alkem and the dis- trict court. First, the undisputed facts under the heading “Infringement” begin with a statement that Alkem does not dispute infringement except that it “contends that it does not infringe the Asserted Claims due to [the] presence of propylene glycol in Alkem’s ANDA Products.” J.A. 1768. Azurity’s view of the disputed stipulation is implausible be- cause it would have Alkem frame the infringement dispute and then, several lines down, turn around and concede the same issue. Second, the disputed stipulation is markedly different than the other undisputed facts under the “Infringement” heading. In a typical example, the parties agreed that “Claims 5 and 7 of the ’948 Patent recite ‘water’” and “Alkem’s ANDA Products contain water, which meets the ‘water’ limitation of claims 5 and 7 of the ’948 Patent.” J.A. Case: 23-1977 Document: 38 Page: 15 Filed: 04/08/2025

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1771. Unlike every other example, the disputed stipulation does not refer to meeting a limitation of any claim. Third, Alkem’s interpretation is more consistent with the origin of the disputed stipulation. It began with Azur- ity’s infringement theory. Even without the disclaimer we discussed supra, the “consisting of” transition presumably renders any ANDA product with propylene glycol non-in- fringing because propylene glycol is not recited in the claims. But the parties appreciated that propylene glycol might find its way into this sort of ANDA product either incidentally—i.e., as part of a flavoring agent mixture—or separately. Azurity’s infringement theory was that all pro- pylene glycol in the ANDA product, even if added sepa- rately, could be deemed part of the claimed “flavoring agent”—a view the district court dubbed Azurity’s “mix- and-match” theory. Azurity, 671 F. Supp. 3d at 494–97, 503–05. The parties began to dispute whether propylene glycol might be found in suitable flavoring agents, and eventually, Azurity admitted “that the plain and ordinary meaning of the claim term ‘flavoring agent’ includes flavor- ing agents without propylene glycol.” J.A. 1134. That ad- mission became the disputed stipulation. With that context, the district court correctly deter- mined that “[t]he stipulation says nothing about whether Alkem’s ANDA contains a flavoring agent with propylene glycol,” a necessary link in its mix-and-match theory of in- fringement. Azurity, 671 F. Supp. 3d at 511. Azurity’s po- sition that the stipulation made infringement fait accompli—contrary to the rest of the infringement section of the pretrial order—cannot be sustained when a far more sensible reading is the one consistent with the stipulation’s origin: making clear that in this field, the relevant flavor- ing agents need not have propylene glycol. The district court correctly concluded that the disputed stipulation did not preclude application of disclaimer in this case. Case: 23-1977 Document: 38 Page: 16 Filed: 04/08/2025

IV Finally, we address the district court’s finding of non- infringement. The district court’s decision that the pres- ence of propylene glycol in Alkem’s ANDA established non- infringement is not clearly erroneous. Accordingly, we af- firm. In a Hatch–Waxman case, “the filing of an ANDA con- stitutes an ‘artificial’ act of infringement for purposes of creating case or controversy jurisdiction. . . . [But] the ul- timate infringement inquiry provoked by such filing is fo- cused on a comparison of the asserted patent claims against the product that is likely to be sold following ANDA approval and determined by traditional patent law princi- ples.” Ferring B.V. v. Watson Lab’ys, Inc.-Fla., 764 F.3d 1401, 1408 (Fed. Cir. 2014) (citing 35 U.S.C. § 271(e)(2)(A)). “[I]f the ANDA ‘defines a proposed generic drug in a man- ner that directly addresses the issue of infringement, it controls the infringement inquiry.’” Par Pharm., 44 F.4th at 1383 (quoting Abbott Lab’ys. v. TorPharm, Inc., 300 F.3d 1367, 1373 (Fed. Cir. 2002)) (internal quotation cleaned up). The patented formulation is a liquid mixture that “con- sists of” the listed ingredients in the claims of the ’948 pa- tent: buffering agent, water, a sweetener, a preservative, vancomycin hydrochloride, and a flavoring agent. See ’948 patent, claims 5 & 7. Alkem’s ANDA recites a formulation containing: vancomycin hydrochloride, Grape Flavor 501417C (flavoring agent), FD&C Red No. 40 (coloring agent), D&C Yellow 10 (coloring agent), citric acid (pH modifier or buffering agent), propylene glycol (co-solvent), methyl paraben (preservative), propyl paraben (preserva- tive), sucralose micronized (sweetener), and purified water (vehicle). J.A. 3278–79; see also J.A. 2915. The ANDA also lists the ingredients of Grape Flavor 501417C: propylene glycol, flavoring, and ascorbic acid. J.A. 3278. There is no dispute that the ANDA indicates that Alkem’s proposed Case: 23-1977 Document: 38 Page: 17 Filed: 04/08/2025

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generic contains propylene glycol, either through the fla- voring agent or the separately listed propylene glycol. Here, having correctly concluded that Azurity compre- hensively disclaimed propylene glycol, and having correctly ignored the “suitable flavoring agents” stipulation, the dis- trict court in turn found that Azurity failed to prove in- fringement. That was not error. The infringement inquiry here is very simple: propylene glycol was disclaimed; the ANDA contains propylene glycol; therefore there is no in- fringement. To be sure, absent the disclaimer, there could have been some difficult questions to answer. Indeed, the district court held a bench trial where Azurity advanced evidence that propylene glycol would affect the flavoring of the product, and that propylene glycol and grape flavoring collectively are a flavoring agent. Azurity, 671 F. Supp. 3d at 496–97. But these topics turned out to be of little mo- ment in the district court’s final analysis, and we agree. Because Azurity disclaimed any presence of propylene gly- col, the district court’s finding that Alkem’s ANDA product does not infringe the claims of the ’948 patent is not clearly erroneous. CONCLUSION For the foregoing reasons, we affirm the district court’s finding that Alkem’s ANDA product does not infringe the claims of the ’948 patent. AFFIRMED COSTS Costs to Defendant-Appellee.