Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd. ( 2023 )


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  • INTHEUNITEDSTATESDISTRICTCOURT FORTHEDISTRICTOFDELAWARE AZURITYPHARMACEUTICALS,INC., Plaintiff, CivilAction v. No. 20-cv-1094 ALKEMLABORATORIESLTD., Defendant. MEMORANDUMOPINION Goldberg,J.1 May4,2023 This lawsuit was brought under the Hatch Waxman Act for patent infringement pursuant to 35 U.S.C. § 271(e)(2)(a). Plaintiff Azurity Pharmaceuticals, Inc. (“Azurity”) claims that an Abbreviated New Drug Application (ANDA), submitted by Defendant Alkem Laboratories Ltd. (“Alkem”), infringes U.S. Patent No. 10,959,948 (the ’948 patent), titled “Composition and methodforvancomycinoralliquid.”Azurityassertsclaims5,7,8,and9ofthe’948patent. After presiding over a two-day bench trial, I find that Azurity has failed to establish, by a preponderance of the evidence, that Alkem’s ANDA infringes any asserted claim. This opinion setsforthmyreasonsinreachingthisverdict.2 1 Pursuantto28U.S.C.§292(b),IhavebeendesignatedtoserveasavisitingjudgefortheDistrict ofDelawaretohandlethismatterandotherDistrictofDelawarecases. 2 I previously issued a decision in another case between these same parties, Azurity Pharms., Inc.v.AlkemLab’ysLtd., No. 19-cv-2100,2023 WL 1927613 (D.Del. Feb. 10, 2023). Thatcase is somewhat similar to the one currently before me in that the identity of the parties, plaintiff’s main witness, the patents at issue being for liquid formulations of existing drugs, and the main infringementdisputebeingthepresenceofanunlistedingredient,arethesame. I. BACKGROUND Althoughmostofthefactsinthiscasepertaintooralliquidsandaretechnicalinnature,the issuecomesdowntoasimplequestion: MayAzurityproveinfringementbygroupingtogethertwo ingredients of Alkem’s accused product, grape flavor and propylene glycol, such that the group, collectively, is a flavoring agent? If so, Azurity has proven infringement. If not, there is no infringementandAlkemisentitledtoajudgmentinitsfavor. The patent in suit claims liquids containing the antibiotic vancomycin, as well as methods for treating Clostridium difficile bacterial infections using these liquids. Azurity’s invention was to take vancomycin, which had been used in solid form for decades, and mix it with water while keepingtheliquidstableanduniformoveraperiodofatleastoneweek. Alkem’sANDAisalsoa mixtureofvancomycininwaterthatisstableforatleastoneweek. The parties agree that Alkem’s ANDA satisfies most asserted claim limitations. But, ac- cording to Alkem, its ANDA contains an ingredient that is not recited in any asserted claim: a chemical called propylene glycol. Alkem argues that the presence of this unclaimed ingredient defeats infringement of all asserted claims. Alkem further presses that to the extent Azurity is assertinginfringementbaseduponpropyleneglycolbeingincludedintheassertedclaims,Azurity disclaimedthatingredientduringtheprosecutionofthe’948patent. Azurityrespondsthatpropyleneglycolfitswithintheassertedclaimsbecauseitispartofa “flavoringagent,”whichisaningredientpresentinallassertedclaims. Attrialandinpretrialsub- missions, Azurity attempted to show that propylene glycol by itself was a flavoring agent because it has a slightly sweet taste that helps mask the bitterness of vancomycin. In post-trial briefing, however, Azurity’s focus shifted to a more nuanced argument: that even if propylene glycol by itself is not a flavoring agent, once it is added to Alkem’s ANDA product, it combines with the drug’s grape flavor to form a mixture that, collectively, is a flavoring agent. (See Azurity’s Post- TrialBriefat6(describinghowgrapeflavordissolvesintoallthepropyleneglycolintheANDA); id.at9(“AllofthePGactsasavehicleforflavorandthusasaflavoringagent.”).) Azurity disagrees with Alkem’s prosecution history argument on two grounds. First, Azu- ritycontendsthatAlkemforfeiteditsopportunitytomakeargumentsaboutthescopeoftheasserted claims—includingargumentsbasedontheprosecutionhistory—becauseAlkemstipulatedthatno claim terms required construction. Azurity also presents an alternative reading of the prosecution history in which it posits that statements to the Examiner did not disclaim all uses of propylene glycolintheclaimedinvention—suchasinaflavoringagent. II. PROCEDURALHISTORY Azurity initially filed this lawsuit on August 20, 2020, asserting claims against Alkem underpatentsthathavesincebeendroppedfromthelitigation. Claimsforinfringementofthe’948 patentwereaddedbywayofaSecondAmendedComplaintonJune21,2021. AninitialschedulingordersetahearingtoconstruepatentclaimsunderMarkmanv.West- view Instruments, Inc., 517 U.S. 370 (1996), for November 18, 2021. On August 18, 2021, the parties filed a letter stating that “they are in agreement that no terms of the patents-in-suit require construction.” (ECF No. 84.) The Markman hearing was accordingly canceled and no briefing or evidencewastakenonissuesofclaimconstruction. On August 3, 2022, Alkem filed a letter to “advise the Court that a claim construction dispute will require resolution.” (ECF No. 148.) According to Alkem, that dispute was whether Azurity limited the scope of its claims in the prosecution history to exclude propylene glycol. Azurityrespondedthatit“hasnoobjectiontotheCourtresolvingallegedclaimconstructionissues to the extent the Court finds it necessary as part of trial and post-trial briefing.” (ECF No. 149.) However, Azurity argued that Alkem “waived” its prosecution history disclaimer argument by not raising it sooner—such as at a Markman hearing. Azurity repeated this waiver argument in its pretrialsubmissions. I held a two-day bench trial on October 3 and 6, 2022. I decided that, in the interest of efficiency, I would allow Alkem to present evidence in support of its disclaimer argument but would also permit Azurity to advocate that it was prejudiced by Alkem’s late assertion of this argument. (N.T. 23-24.) Azurity’s counsel responded that it would make a showing of prejudice “at the appropriate time” but at trial Azurity did not point to evidence of prejudice. (N.T. 24; ECF No.164.) Followingsubmissionofpost-trialbriefs,IheardclosingargumentsonApril17,2023. The issueofinfringementisnowripefordecision. III. FACTS A. ScientificBackground (1) “Vehicles,”“Solvents,”and“Carriers” This case involves liquid drugs made from water with added ingredients—i.e. “water with stuffinit.”(N.T.63(Little).) Whentalkingaboutthesedrugs,theterms“liquidvehicle,”“carrier,” and “solvent” are synonymous and refer to “something that dissolves something else,” or, alterna- tively, “the large amount of stuff”—i.e., water—“that everything else is in.” For example, water canbeasolventforsugar. (N.T.63(Little);N.T.154-55(Forrest).) (2) FlavoringAgents The active ingredient in Azurity’s invention—vancomycin—has an unpalatable bitterness thatneedstobemaskedifthedrugistakenorally. (N.T.81(Little).) Thisiswhereflavoringagents comeintoplay. According to Azurity’s expert Dr. Steven Little,3 the term “flavoring agent” is used to mean “a mixture of ingredients that imparts flavor to a formulation.” (N.T. 67 (Little).) Both parties’ experts agreed that a single flavoring agent may contain multiple ingredients. (N.T. 80-81 (Little);N.T.245(Forrest);’948patentat11:20-24.) Theyalsoagreedthatnoteveryingredientina flavoringagenthastobeflavorfulbyitself—thetermencompassesother,non-flavorful,ingredients that“enable”themixtureasawholetoimpartflavor. (N.T.80-81(Little);N.T.245(Forrest).) (3) PropyleneGlycol TheprimarydisputedinfringementissueiswhetherAlkem’sANDAinfringestheasserted claims despite containing propylene glycol. Some discussion of propylene glycol is therefore required. Use in Flavoring Agents Propylene glycol is widely used as a solvent. (N.T. 156-57 (Forrest).) In particular, it is commonly used as a solvent in flavoring agents because it helps dissolve flavorful chemicals. It also has other properties desirable in flavoring agents, such as mixing readily with water and not evaporating. (N.T. 85, 89-91 (Little); N.T. 154, 245, 156-59 (Forrest).) 3 Dr.Littlewasofferedwithoutobjectionasanexpertinpharmaceuticalformulationsandthede- signanddevelopmentofpharmaceuticaldosageforms. (N.T.53.) Dr.Littlehasundergraduateand graduatedegreesinchemicalengineeringandhasworkedonnumerousprojectsinpharmaceuticals overthecourseofhiscareer,amongotherimpressivequalifications. (N.T.57-58.) Taste Although propylene glycol is widely used in flavoring agents, by itself it has been described as “practically odorless,” sweet, slightly acrid, and having a slight taste. (N.T. 157-58 (Forrest, citing Rowe); N.T. 87, 93 (Little).) The Centers for Disease Control (CDC) notes that propylene glycol is commonly used in food precisely because it is “practically tasteless.” (N.T. 159-61 (Forrest, citing DTX-1018).) According to Alkem’s expert Dr. Laird Forrest,4 propylene glycol would generally not be considered for use as a flavor by itself because it has practically no taste. (N.T. 162 (Forrest).) Azurity’s expert Dr. Little also could not name a single product that usesjustpropyleneglycolforflavor. (N.T.128(Little).) Azurity presented examples in published literature mentioning the possible use of propy- lene glycol to enhance taste—although those examples were quite different from Alkem’s grape- flavored ANDA product. Those examples included: (1) a patent application for a lip balm men- tioningthatpropyleneglycol’ssomewhatsweettasteenhancedtheflavorofthefinalcomposition, (N.T. 97 (Little); PTX-164 (Breha)); and (2) a patent application reporting that a small amount of propylene glycol could ameliorate the “resinous” taste of an ingredient in a beverage, (N.T. 98-99 (Little); PTX-165 (Fuwa).) Azurity also referenced a study of two subjects in which one subject was able to taste 0.8 milligrams per milliliter of propylene glycol in filtered water and the other subject could only taste it at a higher concentration. (N.T. 94-96 (Little); PTX-175 (Alexander).) Forcomparison,Alkem’sgrape-flavoredANDAliquidcontainsabout1milligrampermilliliterof propyleneglycol. (UndisputedFacts¶56.) Neither party offered any direct evidence as to whether propylene glycol would have any 4 Dr. Forrest was offered without objection as an expert in pharmaceutical formulation science. (N.T. 142-44.) He is a professor of pharmaceutical chemistry who has worked for many years in drugformulations,amongotherimpressivequalifications. (N.T.146.) discernible effect on the taste of a grape-flavored liquid drug product. (See N.T. 102-03, 112-13 (Little);N.T.168(Forrest).) B. Azurity’sPatentonVancomycinOralLiquids Azurity’spatentinthiscaseisU.S.PatentNo.10,959,948(the’948patent). Azurityasserts claims5,7,8,and9ofthispatent. Claim5isrepresentativeoftheseclaimsandreads: A non-sterile stable liquid formulation formulated for oral administration, con- sistingof: (a) abufferingagent,whereinthebufferingagentisselectedfromthegroup consistingofcitricacid,sodiumcitrate,[andmanyotherchemicals], (b) water, (c) asweetener, (d) a preservative, wherein the preservative is selected from the group con- sisting of sodium benzoate, parabens, benzoic acid, potassium sorbate, benzylalcoholorsaltsthereof, (e) vancomycinhydrochloride,and (f) flavoringagent, wherein the non-sterile stable liquid formulation is homogenous and stable for atleast1weekatambientandrefrigeratedtemperatureandhasapHof2.5-4.5. (’948patent,claim5(emphasisadded).) Theterm“consistingof,”whichintroducestheingredient list, “is a term of patent convention meaning that the claimed invention contains only what is expressly set forth in the claim” and “excludes any element[,] step, or ingredient not specified in the claim.” Multilayer Stretch Cling Film Holdings, Inc. v. Berry Plastics Corp., 831 F.3d 1350, 1358(Fed.Cir.2016). Propyleneglycolisnotamongthelistedingredientsclaim5. The ’948 patent’s specification mentions “propylene glycol” only one time—as an ex- ample of a “liquid vehicle” that could have been used instead of water to dissolve vancomycin. (’948 patent, col. 13:29.) The specification does not mention propylene glycol in connection with flavoring agents. However, the parties agree that “[s]uitable flavoring agents for use in the As- sertedClaimsincludeflavoringagentswithorwithoutpropyleneglycol.”(UndisputedFacts¶92.) Dr. Little also testified that a person of ordinary skill in the art (POSA) would understand the specification’s reference to “compounded” flavoring agents to include flavoring agents containing propyleneglycol. (N.T.129(Little).) C. Alkem’sANDA The accused product is an abbreviated new drug application (ANDA) submitted by Alkem to the Food and Drug Administration (FDA). Like the claimed invention, Alkem’s product is a liquid formulation of vancomycin designed for oral administration. (Undisputed Facts ¶¶ 44-48.) ItisundisputedthatAlkem’sANDAcontainsmanyofthesameingredients(and,whereapplicable, inthesameamounts)astheassertedclaims. (SeeUndisputedFacts¶¶64,68.) (1) RelevantIngredients Only three ingredients of Alkem’s ANDA are relevant to the infringement analysis. These are: parabenpreservatives,grapeflavor,andpropyleneglycol. Morespecifically: 1. The preservative in Alkem’s ANDA consists of methyl paraben and propyl paraben (col- lectively,“parabens”or“parabenpreservatives”). (UndisputedFacts¶¶49,84.) 2. The grape flavor in Alkem’s ANDA consists of 0.0125 milligrams per milliliter of a sub- stance identified as “Grape Flavor 501417C.” (Undisputed Facts ¶ 51-52.) It is made up of threeofitsowningredients,whichare: a. 92.5%propyleneglycol, b. 7.496%flavorings(i.e.,grape-flavoredchemicals),and c. 0.004%ascorbicacid. Thus, only about 7% of the grape flavor in Alkem’s ANDA consists of substances that actually taste like grape; most of the rest is propylene glycol. (N.T. 68-70 (Little).) The reason for using propylene glycol is that the grape-flavored chemicals dissolve poorly in water but easily in propylene glycol. (N.T. 71-72 (Little); N.T. 164 (Forrest).) Alkem’s ANDA describes the whole of Grape Flavor 501417C, including its propylene glycol, as a “flavoringagent.”(N.T.76-77(Little).) 3. Alkem’s ANDA also contains an additional 1 milligram per milliliter of propylene gly- col—about a hundredfold more propylene glycol than in the grape flavor. (Undisputed Facts ¶ 56; N.T. 164 (Forrest).) The ANDA describes this ingredient as a “co-solvent to dissolvepreservative.”(DTX-1041at360.) It is important to note that propylene glycol is added to Alkem’s ANDA in two different ways. First, the commercially available “Grape Flavor 501417C” that Alkem uses to flavor its ANDAcontainspropyleneglycol. Second,Alkem’sANDAcontainsanadditional1milligramper milliliterofpropyleneglycoldescribedasaco-solvent. Forclarity,Iwillrefertothesetwosources of propylene glycol as the “grape flavor” propylene glycol and the “co-solvent” propylene glycol. Theparties’infringementdisputefocusesonthe“co-solvent”propyleneglycol. Theparties’expertsagreedthateventhoughthetwopropyleneglycolsareaddedseparately, theyarechemicallyidentical. Itisalsoundisputedthat,oncemixed,bothpropyleneglycolsinteract equallywiththegrape-flavoredchemicalsinGrapeFlavor501417C.(N.T.78-79(Little);N.T.166, 246(Forrest).) Both sides presented somewhat speculative testimony regarding whether the “co-solvent” propylene glycol in Alkem’s ANDA actually helps to dissolve the paraben preservatives. Dr. For- resttestifiedthatthestatementwas“accurate,asfaras[hecould]tell.”(N.T.170-71(Forrest).) He noted that methyl and propyl paraben are poorly soluble in water, and thus it would make sense to add propylene glycol to help dissolve them. (N.T. 163, 169-70 (Forrest).) Dr. Little seemed to agree with this testimony, acknowledging that the ANDA “somewhat accurately characterized” propylene glycol as a co-solvent, although he considered the ingredient “multifunctional.” (N.T. 78, 118-19 (Little).) However, Dr. Little did suggest that even if propylene glycol did act as a sol- vent for the parabens, it was not “necessary” for that purpose. (N.T. 105-07 (Little).) Specifically, Dr. Little referenced a study in Alkem’s ANDA submission in which the “co-solvent” propylene glycol was removed and, with or without this ingredient, the drug was a “[p]ale yellow colored, grapeflavoredsolution.”(DTX-1041at368.) InDr.Little’sview,thislackofchangewhenremov- ing the “co-solvent” propylene glycol showed that the parabens would remain dissolved without it. (N.T.105,107(Little).) Dr.Forrestdisagreedwiththisinterpretation,opiningthattheparabens were present in such a small amount that a failure to dissolve them would be invisible to this naked-eyetest. (N.T.186-87,192(Forrest).) (2) Effectofthe“Co-Solvent”PropyleneGlycolontheTasteofAlkem’s ANDA The parties disputed whether the “co-solvent” propylene glycol would affect the taste of Alkem’s ANDA, but offered little evidence to support their respective positions. For example, neither expert tested (by tasting or otherwise) the product itself or any other grape-flavored liquid. (SeeN.T.102-03,112-13(Little);N.T.168(Forrest).) Based principally on statements in published literature that propylene glycol can have a perceptible taste in, for example, filtered water, Dr. Little opined that the “co-solvent” propylene glycol would “enhanc[e]” the taste of Alkem’s ANDA. (N.T. 97-100 (Little).) But Dr. Little was vague as to what exactly its effect would be. He did not directly answer questions on cross- examination as to whether propylene glycol would make the ANDA product “grapier” or if the productwould“tasteright”withoutit: Q.Inyourview,it’sgrapierifweaddtheextrapropyleneglycol? A.Iwouldsaythatitwould,forallthereasonsIsaidbefore,enhancethestability over time, the uniformity of that grape flavor. It would also aid in something that’snotdiscussedhere,whichismaskingthebitterflavorofthedrug. Q. ... Would Alkem’s product taste right if Alkem didn’t add the propylene glycolcosolvent? A. I don’t think that particular experiment was done, but it would enable, espe- ciallyatthatconcentration,forallthereasonsItalkedaboutinthosereferences, anotherlevelofuniformityandalsomaskingandstability. (N.T.111-12.) Dr. Little was questioned about an experiment described in Alkem’s ANDA submission that reported the product remained “grape flavored” when the “co-solvent” propylene glycol was removed. (DTX-1041at386.) Whenaskedtoreconciletheexperiment’sconclusionthatremoving propylene glycol did not change whether the drug was “grape flavored” with his own opinion that propyleneglycolenhancesflavor,Dr.Littledidnotdenythatremovingthe“co-solvent”propylene glycol might have no “discernible effect on the taste,” but referred generally to the taste-related functionsmentionedforpropyleneglycolinpublishedliterature. (N.T.111-12(Little).) Alkem’s expert Dr. Forrest testified that he had seen “no indication” that the co-solvent propylene glycol in Alkem’s ANDA has “anything to do with the flavoring agent” or has “any discernible effect” on it. (N.T. 165, 168 (Forrest).) But again, Dr. Forrest offered no testing to supporthisopinion. (3) Dr.Little’sOpinionThatthe“Co-Solvent”PropyleneGlycolIsPartofa “FlavoringAgent” Azurity’s primary infringement contention is not that propylene glycol is a flavoring agent by itself. Rather, Azurity’s contention is that propylene glycol and grape flavor collectively are a flavoring agent. Dr. Little offered this opinion at trial, explaining that the “co-solvent” propylene glycol would contribute to the drug’s flavor in the following ways: it would help keep the grape- flavored chemicals dissolved; it would increase the uniformity of the drug’s flavor; and it would “maskunpalatabletastes.”(N.T.64,77,87-88(Little).) Dr. Little suggested (although he did not expressly opine) that if a “very large amount” of propylene glycol were added to a vancomycin liquid, it might no longer be accurate to call propyleneglycola“flavoringagent.”(N.T.101-02,116-17(Little).) Dr.Littlecouldnotsayexactly how much was a “very large amount,” but suggested that if the drug were “60 percent” propylene glycol,thatmightbeovertheline. (N.T.117-18(Little).) IV. PROSECUTIONHISTORYOFTHE’948PATENT AlkemurgesthattheprosecutionhistoryestablishesthatAzuritydisclaimedpropylenegly- col. Thepatentinquestion,the’948patent,issuedfromapplication16/941,400(the’400applica- tion). The ’400 application was a “continuation” of application 15/126,059 (the ’059 application). Thesamepatentexaminerhandledboth. “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 subsequently issued patents that contain the same claim limitation.” Elkay Mfg. Co. v. Ebco Mfg. Co., 192 F.3d 973, 980 (Fed. Cir. 1999). Alkem focuses its disclaimer argument on events that occurred dur- ing prosecution of the ’059 application rather than the ’400 application. On June 16, 2020, the Examiner notified Azurity that the claims of the ’059 application would be allowed, and Azurity subsequently initiated the ’400 application on July 28, 2020 using language very similar to what had recently been allowed in the ’059 application. In particular, Azurity imported the identical claimlimitations“flavoringagent”and“consistingof”fromthe’059applicationintothe’400ap- plication. Nootheramendmentsorargumentsrelevanttothiscaseoccurredinthe’400application between July 28, 2020 and when the Examiner ultimately allowed those claims on October 30, 2020. Basedonthistimingandtheidenticalsimilarityintherelevantclaimlanguage,Iagreewith Alkem that any actions Azurity took to narrow the scope of the terms “flavoring agent” and “con- sisting of” in the ’059 application apply to the ’400 application as well, and thus to the asserted claims in this case from the ’948 patent. Azurity does not argue to the contrary in its post-trial brief. (SeeAzurity’sPost-TrialBriefat14-15.) Therelevantpartsoftheprosecutionhistoryaresummarizedbelow. A. Azurity’sFirstAttemptatClaimingVancomycinLiquids: FullyOpenClaims OnSeptember14,2016,Azuritysoughtapprovalofasetofclaimsforvancomycinliquids. Thefollowingclaim(withindependentclaimsinserted)isillustrativeofthatset: A non-sterile stable liquid formulation comprising a compounded solution of vancomycin hydrochloride that is homogenous and stable for at least 30 days at ambient and refrigerated temperature conditions, wherein the compounded solutionispreparedfromvancomycinhydrochlorideandaliquidsolutionthatis notOra-Sweet,whereintheliquidsolutioncomprises: (a) abufferingagent, (b) water, (c) asweetener, (d) aflavoringagent, (e) apreservative,and (f) adye. (DTX-1004Aat5338.) Becausethisclaimusedtheterm“comprises,”itwasan“openclaim”—one that allowed for unlisted ingredients in addition to what appeared in the claim. MagSil Corp. v. HitachiGlob.StorageTechs.,Inc.,687F.3d1377,1383(Fed.Cir.2012). TheExaminerrejectedAzurity’sproposedopenclaimasbeingobviousinlightoftheprior art, in particular Palepu, U.S. Patent Application 2016/0101147, “Formulations of Vancomycin.” (DTX-1004B at 53846-47.) Palepu disclosed vancomycin liquids for intravenous rather than oral administration, and its liquids were described as stable. (N.T. 277 (Little); PTX-188 at 8531.) Palepu did not disclose flavoring agents because Palepu’s formulations were not taken orally, but the Examiner felt that adding flavoring agents to Palepu’s formulations would have been obvious inlightofotherreferences. (DTX-1004Bat53848;N.T.277(Little).) AzurityresistedtheExaminer’sobviousnessdeterminationbasedonargumentsnotrelevant here, but the Examiner continued to reject Azurity’s fully open claims. (DTX-1004C at 53876; DTX-1004Dat54076.) B. SecondAttempt: NegativeLimitations AzurityproposednewclaimlanguageonJanuary29,2019. Thefollowingisillustrative: Aliquidsolutioncomprising: (a) 0.12%(w/v)anhydrouscitricacid, (b) water, (c) 0.2%(w/v)sucralose, (d) 0.05%(w/v)ofaflavoringagent, (e) 0.1%(w/v)sodiumbenzoate, (f) 0.0002%(w/v)D&CYellowNo.10, (g) 0.000038%(w/v)FD&CRedNo.40, wherein the liquid solution does not comprise a [sic] propylene glycol, and wherein the liquid solution is homogenous and stable for at least 30 days at ambientandrefrigeratedtemperatureconditions.5 (DTX-1004Eat54101.) Thelimitationbeginning“whereintheliquidsolutiondoesnotcomprise” is known as a “negative limitation” because it states what ingredients are excluded from the in- vention. See Nike, Inc. v. Adidas AG, 812 F.3d 1326, 1347 (Fed. Cir. 2016), overruled on other grounds, Aqua Prod., Inc. v. Matal, 872 F.3d 1290 (Fed. Cir. 2017). Azurity argued that adding a negative limitation to exclude propylene glycol distinguished Palepu because Palepu’s formula- tionsusedpropyleneglycol. (DTX-1004Gat54106-07.) TheExaminerwasnotconvincedthatexcludingpropyleneglycoladequatelydistinguished Palepu because that prior art actually discussed two different solvents—propylene glycol and polyethylene glycol. Because Azurity had only excluded propylene glycol, Palepu was not dis- 5 Forreadability,alterationsareomittedfromallquotedclaimlanguage. tinguished. (DTX-1004Fat54096.) Azurity also attempted to distinguish Palepu using a negative limitation that excluded a “suspendingagent”(or,insomeproposedclaims,“propyleneglycolorasuspendingagent”). Over the next six months, Azurity tried and failed to convince the Examiner that propylene glycol and polyethyleneglycolweresuspendingagentssuchthatexcludingsuspendingagentsnecessarilyex- cludedboth. (DTX-1004Gat54106-07.) TheExaminerremainedunpersuaded: evenifpropylene glycol and polyethylene glycol could sometimes be suspending agents, they were not suspending agentsinPalepu. Forthatreason,theExaminerconcludedthatexcluding“suspendingagents”did notdistinguishPalepu. (DTX-1004Hat54204.) C. ThirdAttempt: AMixofNegativeLimitationsand“Consistingof” During a discussion between Azurity and the Examiner on January 30, 2019, the Exam- iner suggested that Azurity could overcome the problems with its negative limitation claims by “amend[ing] using consisting of language for the solvent or carrier such that it would no longer require the polyethylene or [propylene] glycol.” (DTX-1004F at 54096.) Azurity heeded the Ex- aminer’sadvice,butonlypartly. On February 11, 2019, Azurity proposed new claims. Some of those claims continued to use negative limitations on “propylene glycol or a suspending agent,” with Azurity still insisting that this limitation was adequate to exclude both of Palepu’s solvents. But Azurity also intro- ducedclaimsthatlackednegativelimitationsandreplacedthemwiththewords“consistingof”(as proposedbytheExaminer): Aliquidsolutioncomprisingacarrierconsistingof: (a) 0.1-0.4%w/vanhydrouscitricacid, (b) water, (c) 0.1-0.3%w/vsucralose, (d) 0.01-0.1%w/vofaflavoringagent, (e) 0.08-0.2%w/vsodiumbenzoate,and (f) 0.0001-0.0003%w/vofadye, whereintheliquidsolutionfurthercomprisesvancomycin. (DTX-1004G at 54113.) By using “consisting of,” Azurity made these claims “closed” to unlisted ingredients—such as those in Palepu, including propylene glycol. See PPG Indus. v. Guardian In- dus. Corp., 156 F.3d 1351, 1354 (Fed. Cir. 1998) (“[C]losed claims ... are written in a ‘consisting of’format....”). Azurity continued to assert that both its negative-limitation claims and its new “consisting of” claims should be allowed over Palepu. (E.g., DTX-1004G at 54106-10.) Azurity attached to these assertions a declaration by chemical engineer Dr. Steven Dinh, which closed with the followingobservation: As shown in the Application, the diluent and the compounded solutions do not have propylene glycol or polyethylene glycol, both of which were noted as im- portantcomponentsinPalepu’scompositions. (DTX-1004G at 54119.) Although Dr. Little testified that he read Dr. Dinh’s statement about the lack of propylene glycol as only applying to Azurity’s negative-limitation claims (and not, by implication, its “consisting of” claims), there is no language in the declaration itself identifying particularclaims. (N.T.308,336(Little).) TheExaminerrejectedAzurity’snew“consistingof”claims,butfordifferentreasonsthan in previous rejections. The Examiner determined that the way Azurity had used “consisting of” was unclear and indefinite. Specifically, the claim recited “a liquid solution comprising a carrier consisting of” various ingredients. Thus the claim as a whole was open (“comprising”), but some subset of it—a subset called the “carrier”—was closed (“consisting of”). According to the Ex- aminer, this made it “unclear which components [were] part of the carrier and which [were] not,” and,consequently,“unclearwhichunrecitedcomponents[were]permittedbytheclaimandwhich [were]not.”(DTX-1004Hat54185.) The Examiner further rejected Azurity’s new “consisting of” claims as obvious. But, pre- sumably because it was unclear what, exactly, the “consisting of” limitation excluded from the invention, the Examiner’s obviousness rejection did not discuss propylene glycol, polyethylene glycol, “consisting of,” or Palepu (other than a single reference which seems to be a typo for “Ulrich”). (DTX-1004Hat54198-200.) D. FourthAttempt: “Consistingof” Azurity followed up with the Examiner on August August 15, 2019, submitting amended claimsandfurtherargument. Becausethesenewclaimsusedthesamelimitations“flavoringagent” and “consisting of” that appear in the ’948 patent, Azurity’s statements about the scope of these claimsareimportanttoAlkem’sdisclaimerargument. (1) Azurity’sNewClaimLanguage Azurity’s amended claims now exclusively used “consisting of” and abandoned negative limitations. Due to the complexity of prior and later amendments, it is necessary to examine three of those claims: (1) a negative limitation claim that Azurity converted to a “consisting of” claim but ultimately canceled entirely (claim 16); (2) a negative limitation claim that Azurity converted to a “consisting of” claim and that was eventually allowed (claim 20); and (3) a claim that had previouslyused“consistingof”(claim24). First, claim 16 had previously used negative limitations but Azurity amended it to use “consistsof”(whichhasasimilarconstructionto“consistingof”): [Claim16]Akitcomprisinganon-sterile100%w/wvancomycinhydrochloride powder,pre-measuredintoarespectiveunitofuseamount, a second container consisting of an oral liquid solution, pre-measured into a respectiveunitofuseamount,and instructionsforuse, whereintheoralliquidsolutionconsistsof: anhydrouscitricacid,water,asweet- ener,aflavoringagent,sodiumbenzoate,andadie, whereinthefirstandsecondcontainersareofasizesuchthatthevancomycinhy- drochloridepowderandoralliquidsolutioncanbecombinedineitherthefirstor second container to produce a compounded solution of vancomycin hydrochlo- ride, and wherein the compounded solution of vancomycin hydrochloride has a pH of 2.5 to 4.5 and is homogenous and stable for at least 30 days at ambient andrefrigeratedtemperatureconditions. (DTX-1004Kat54243.) Claim20wasalsorewordedtochangeitsnegativelimitationto“consistingof”: [Claim 20] A non-sterile stable liquid formulation formulated for oral admin- istration, consisting of vancomycin hydrochloride, anhydrous citric acid, water, a sweetener, a flavoring agent, sodium benzoate, and a dye, wherein the non- sterile stable liquid formulation is a compounded solution of vancomycin hy- drochloride that is homogenous and stable for at least 30 days at ambient and refrigerated temperature conditions, and wherein the compounded solution has ahighsolubilityinwaterandapHof2.5-4.5. (DTX-1004Kat54244.) Claim24hadpreviouslyused“consistingof”languagebuthadsufferedfromanambiguity in that only a subset of it (the “carrier”) was brought within the limitation. Azurity reworded the claimtoapplythe“consistingof”limitationtotheentireliquid: [Claim24]Aliquidsolutionconsistingof: (a) 0.1-0.4%w/vanhydrouscitricacid, (b) water, (c) 0.1-0.3%w/vsucralose, (d) 0.01-0.1%w/vofaflavoringagent, (e) 0.08-0.2%w/vsodiumbenzoate, (f) 0.0001-0.0003%w/vofadie,and (g) vancomycinhydrochloride,and wherein the liquid solution is formulated for oral administration, homogenous, andstableforatleast30daysatambientandrefrigeratedtemperatureconditions. (DTX-1004Kat54244-45.) (2) ArgumentsSubmittedtotheExaminerinSupportof“Consistingof” Claims Inargumentsattachedtoitsnewclaimlanguage,AzuritytoldtheExaminerthatithadnow deleted the problematic negative limitation on suspending agents—which had failed to exclude polyethyleneglycol—fromclaim16infavorof“consistsof”language. Thenewlanguage,Azurity argued,excludedbothpropyleneglycolandpolyethyleneglycolandthusdistinguishedPalepu: ...Palepudisclosesliquidvancomycin-containingcompositionsthatinclude(a) vancomycin or a pharmaceutically acceptable salt thereof, (b) a polar solvent comprising propylene glycol, polyethylene glycol, or mixtures thereof, (c) lacticacid,alactatesaltormixturesthereof,andoptionally(d)apHadjuster. ... The absence of propylene glycol and polyethylene glycol in the claimed inven- tion,inpart,distinguishesitfromthecitedreference. Palepu clearly teaches that the polar solvent (comprising propylene glycol, polyethylene glycol, or mixtures thereof) and lactic acid ... are important components in its compositions. ... Palepu emphasizes that it is the interac- tion/combination of its polar solvent (e.g. propylene glycol) and lactic acid ... thatgivesthesolutionslong-termstability. ... ... At least for the reasons stated above, the compositions of Palepu do not fall within the scope of the claimed invention. The claimed invention does not in- cludethepolarsolventsorlacticacidofPalepu. ... (DTX-1004K at 54251-52 (bold text in original, underlining added).) Azurity made a similar argumentwithrespecttoclaim20butwithfewerwords: Asexplainedabove,Paleputeachesthatitspolarsolvents(e.g.propyleneglycol) and lactic acid ... confer its compositions with long-term stability. The claimed invention is an oral vancomycin formulation that is stable for 30 days, and it does not include the polar solvents or lactic acid of Palepu. The skilled artisan would not have had a reasonable expectation of success in producing a stable, oral vancomycin formulation, by combining Palepu and Accord and modifying thesolutionbyremovingthepolarsolventsand/orthelacticacidofPalepu. (DTX-1004Kat54254(underliningof“stable”and“oral”inoriginal,otheremphasisadded).) With respect to claim 24 (the claim that had previously used “consisting of” language), Azurity did not discuss the impact of Palepu or the presence or absence of propylene or polyethy- lene glycol. Although Azurity’s reasons for not addressing Palepu cannot be known with cer- tainty,thelogicalexplanationisthattheExaminerhadalsonotpreviouslydiscussedtheimpactof Palepuonclaim24—apparentlybecausetheclaim’spreviouslyindefinitelanguagemadeitunclear whetherPalepu’singredientswereevenexcluded. (3) Allowance On February 20, 2020, the Examiner finally removed the obviousness rejection as to some claims—including claim 24—but continued to reject these claims for other reasons not relevant here. (DTX-1004M.) As to claim 16, the Examiner once again faulted Azurity for using a mix of open and closed language. (DTX-1004M at 54408.) Azurity ended up canceling claim 16. (DTX-1004N.) On June 16, 2020, the Examiner stated that all remaining claims would be allowed. In doingso,theExaminerexplained: The closest prior art to Palepu [sic]6 ... teaches a non-sterile stable liquid for- mulation having vancomycin hydrochloride together with either propylene gly- col or polyethylene glycol in the liquid formulation. The instant claims exclude the presence of propylene glycol or polyethylene glycol in view of the consist- ing 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. (DTX-1004Oat54460(emphasisadded).) 6 Presumablythisshouldread: “Theclosestpriorart,Palepu,....” E. The’400Application The ’400 application that became the ’948 patent in this case started off with “consisting of” claims on July 28, 2020, chronologically after the back-and-forth recounted above from the ’059application. Thefollowingisillustrativeofthe’400application’sclaims: A non-sterile stable liquid formulation formulated for oral administration, con- sistingof: (a) abufferingagent,whereinthebufferingagentisselectedfromthegroup consistingofcitricacid,sodiumcitrate,[andmanyothers], (b) water, (c) asweetener, (d) sodiumbenzoate, (e) vancomycinhydrochloride,and (f) flavoringagent, wherein the non-sterile stable liquid formulation is homogenous and stable for atleast1weekatambientandrefrigeratedtemperatureandhasapHof2.5-4.5. (DTX-1008at56004.) The Examiner first notified Azurity on September 18, 2020 that the ’400 application’s claimswouldbeallowed. (DTX-1008at58509.)7 7 The Examiner’s explanation for allowing these claims is not particularly informative on the disclaimerissue,butIincludeitforhereforcompleteness: Palepu ... teaches that the vancomycin-containing compositions are stable for at least 24 months of storage at a temperature of from about 5 °C to about 25 °C. Without being bound by theory, it is believed that the surprising long-term stability of solutions prepared according to the present invention arises at least inpartfromtheinteractionbetweenlacticacid...,thepolarsolvent(e.g.propy- lene glycol) and vancomycin. Palepu’s formulations require propylene glycol presentasthepolarsolventwithlacticacid... . ... Palepu...teachessolutionswhichhavepropyleneglycolorpolyethyleneglycol solvent present with lactic acid in the liquid formulation. The instant claims re- citeacompositionconsistingofingredientsa-fandisstableandhomogenousfor at least 1 week at ambient and refrigerated temperature, and thus are allowable overtheteachingsofPalepu. Noneofthepriorartteachesorsuggestsacompo- sition consisting of ingredients a-f as claimed that is homogenous and stable for F. Backtrackinginthe’421Application Azurity emphasizes a statement it made to the Examiner in a different patent application after the events described above had occurred. Patent application number 16/892,421 (the ’421 application) was a sibling of the ’400 application—i.e., an application with a common parent. On October13,2020,Azuritywroteinasubmissionaspartofthe’421application: ...Applicant...notesthattheinstantapplicationclaimspriorityto[the’059ap- plication]. Duringprosecutionof[the’059application],Applicantmadecertain argumentsandclaimamendmentswithrespecttopropyleneglycoltoovercome the cited prior art. For the record, Applicant did not disclaim propylene glycol when submitting the arguments in [the ’059 application], and reserves the right toclaimpropyleneglycolintheinstantandfuturecasesinthispatentfamily. (DTX-1007B at 61030.) To place this statement in context, at this point in time, the Examiner had already notified Azurity that the claims of the ’400 application would be allowed (September 18, 2020), and Alkem had already submitted its Paragraph IV letter underlying this lawsuit (July 7, 2020). (Complaint ¶ 19.) Although some activity in the ’400 application occurred between September18,2020andOctober30,2020whenthe’400application’sclaimswerefinallyallowed, noamendmentsorargumentrelevanttopropyleneglycoloccurredduringthattime. (Seegenerally DTX-1008at58509-58554.) V. DISCUSSION The parties agree that Alkem’s ANDA satisfies all limitations of all asserted claims ex- cept for one: the “consisting of” limitation, and, in particular, whether the presence of propylene glycol in the ANDA violates this limitation. The phrase “consisting of” means that the invention “excludes any element[,] step, or ingredient not specified in the claim.” Multilayer Stretch Cling atleastaweekandhasapHfrom2.5-4.5. (DTX-1008at58518-19(emphasisinoriginal).) FilmHoldings,Inc.v.BerryPlasticsCorp.,831F.3d1350,1358(Fed.Cir.2016). Alkemcontends thatitsANDAproductcontainspropyleneglycoland,becausepropyleneglycolisnotlistedasan ingredientinanyassertedclaim,the“consistingof”limitationisnotmet. A. Azurity’sInfringementTheory Ordinarily, infringement is analyzed by taking each element of the asserted claim and matchingittoafeatureoftheaccusedproduct. SeeUnionCarbideCorp.v.TaranconCorp.,682F. Supp.535,541(N.D.Ga.1988);Colev.Kimberly-ClarkCorp.,102F.3d524,532(Fed.Cir.1996) (“Literal infringement of a claim exists when every limitation recited in the claim is found in the accused device ... .”). In this case, because the claim is “closed” to unlisted ingredients, the dis- puteiswhethertheaccusedproductcontainsextraingredientsthatcannotfitwithinanyingredient listed in the claims. Azurity advocates that in analyzing this question, certain ingredients that mightotherwisenotfitwithintheclaimsshouldbecombinedandtreatedasasingleingredient. To prove infringement, Azurity needs to fit each ANDA ingredient within the asserted claims. NoANDAingredientcanbeleftover,becauseanyremainingingredientwouldviolatethe “consistingof”limitation. MultilayerStretchClingFilmHoldings,831F.3dat1358. Azuritycon- tends it does not have to show that each ANDA ingredient individually corresponds to a claimed ingredient. Instead, Azurity asserts that it has proven that mixing and matching certain ANDA ingredients turns them into claimed ingredients. Specifically, Azurity argues that when grape fla- vor is mixed with propylene glycol—both ingredients of Alkem’s ANDA—the combination is a “flavoringagent.”And,becausea“flavoringagent”isaclaimedingredient,propyleneglycolisnot aremainingunclaimedingredientthatwouldviolatethe“consistingof”limitation. AsimplefoodanalogymayhelptoexplainAzurity’sposition. Supposeapatenthasissued for a beverage whose recipe calls for lemonade, ginger, and iced tea, and the accused product was made from lemonade, ginger, iced tea, and water. Applying this analogy to Azurity’s mixing and matchingtheory,lemonadeandwaterintheaccusedproductshouldbegroupedtogetherandchar- acterized, collectively, as “lemonade” (albeit weak lemonade), thus matching the patentholder’s recipe with no extra ingredients. (See N.T. 4/17/23 at 46:4-8 (“[Azurity’s Counsel]: It doesn’t change the fact that it’s lemonade. ... It might be more diluted than lemonade.”).) Similarly, Azu- ritycontendsthatgrapeflavorpluspropyleneglycolshouldbegroupedtogetherandcharacterized, collectively,aslessconcentratedgrapeflavor. (SeeN.T.116(Little)(addingmorepropyleneglycol toaflavoringagentmakesit“[not]asconcentrated”).) As a general matter, Alkem does not dispute that it is legally permissible to prove in- fringement by mixing and matching ingredients. Although neither party cites authority on point, Azurity’s theory finds some support in the rule stating that claims to a mixture ordinarily go to “a compositionthatcontainsthespecifiedingredientsatanytimefromthemomenttheingredientsare mixedtogether.”Mars,Inc.v.H.J.HeinzCo.,L.P.,377F.3d1369,1374(Fed.Cir.2004)(emphasis deleted). Before considering Azurity’s mixing and matching theory, two additional points of clar- ification are needed. First, although Alkem does not contest that, in some cases, a mixing and matching theory might apply, Alkem urges that in this case Azurity “may not challenge Alkem’s ANDA’s consistent characterization of propylene glycol as a cosolvent” by calling it a flavoring agent. (Alkem’sPost-TrialBriefat2.) Forsupport,Alkemcitescasesholdingthatinfringementin aHatch-Waxmancase“iscontrolledbytheANDAspecification”because“drugmanufacturesare bound by strict statutory provisions to sell only those products that comport with the ANDA ... .” Par Pharm., Inc. v. Eagle Pharms., Inc., 44 F.4th 1379, 1383 (Fed. Cir. 2022). But Alkem’s cited principle is not analogous and does not apply here. The issue in Par Pharmaceutical was whether the ANDA’s specification of a drug’s physical characteristics—there, its pH—controlled the in- fringementinquiry. Here,thephysicalcharacteristicsofAlkem’sANDAarenotindispute. Rather, thedisputecentersonhowtheANDA’singredientsfunction. ThefactthattheANDAcallspropy- leneglycola“co-solvent”doesnotprecludeAzurityfromofferingevidencethatpropyleneglycol alsofunctionsasacomponentofaflavoringagent. Second, although Azurity sought to prove at trial that propylene glycol by itself is a fla- voring agent, Azurity all but abandoned that argument in its post-trial brief and now takes the positionthatwhetherpropyleneglycolhasflavoris“immaterial.”(Azurity’sPost-TrialBriefat8.) Azurity pivots for good reason: the evidence it presented at trial in an attempt to show that propy- lene glycol (sometimes described as “virtually flavorless”) has any impact on the taste of Alkem’s ANDA was unpersuasive. Azurity did not test the effect of propylene glycol on the product, and its expert, Dr. Little, was not aware of a single product that uses only propylene glycol for flavor. (N.T. 112-13, 128 (Little).) Studies showing that propylene glycol can have a perceptible taste in, for example, filtered water were not persuasive in demonstrating the effect of propylene glycol in Alkem’s grape-flavored ANDA liquid. I also credit Alkem’s expert Dr. Forrest’s testimony that propylene glycol is generally not something that would be considered for use as a flavor because ithas“soverylittletaste.”(N.T.162.) Thus,IfindthatAzurityfailedtodemonstratebyaprepon- derance of the evidence that propylene glycol standing alone is a flavoring agent. Consequently, Azurity can only prevail on its infringement case if it is established that the ANDA contains a flavoringagent(ingredient(f)inclaim5)madefromacombinationofpropyleneglycolandgrape flavor. With that understanding, I turn to the claim construction dispute at the heart of this litiga- tion. B. AllegedWaiverofAlkem’sDisclaimerArgument Alkem’s case is primarily focused on Azurity having disclaimed propylene glycol in the prosecution history. The parties agree that Alkem’s disclaimer argument is properly viewed as “claimconstruction”becauseitaffectsthescopeoftheassertedclaims. SeeU.S.SurgicalCorp.v. Ethicon,Inc.,103F.3d1554,1568(Fed.Cir.1997)(“Claimconstructionisamatterofresolutionof disputedmeaningsandtechnicalscope,toclarifyandwhennecessarytoexplainwhatthepatentee covered by the claims, for use in the determination of infringement.”). But Azurity asserts that claim construction is inappropriate at this late stage of the litigation, especially after the parties stipulatedthat“notermsofthepatents-in-suitrequireconstruction.”(ECFNo.84.) Adistrictcourthasdiscretiontoconsiderclaim-constructionargumentsattrialprovidedthe parties are afforded notice and an opportunity to be heard and neither party is unfairly prejudiced bytheprocedure. SeePressureProd.Med.Supplies,Inc.v.GreatbatchLtd.,599F.3d1308,1315- 16(Fed.Cir.2010). Certainlytherewillbecaseswhereapartyshouldbeprecludedfrompressing new claim construction disputes late in the litigation so as to avoid surprises at trial. See Keranos, LLC v. Silicon Storage Tech., Inc., 797 F.3d 1025, 1035 (Fed. Cir. 2015). However, two factors demonstratethatsuchpreclusiondoesnotapplyhere. First, Alkem’s disclaimer argument was not a surprise for Azurity. Alkem has maintained since filing its answer that the prosecution history prevents Azurity from proving infringement, and Alkem set out its view of the prosecution history in detail in its motion for judgment on the pleadings. (See Answer, Fourth Separate Defense; Motion, ECF No. 46.) Thus Azurity was on notice more than a year before trial as to precisely which statements in the prosecution history Alkem considered significant and what Alkem contended the effect of those statements would be. I invited Azurity to establish prejudice at trial, and Azurity did not do so, nor did it point to any prejudiceinitspost-trialbrieforduringclosingarguments. (N.T.23-24.) Second, refusing to consider evidence on the meaning of “flavoring agent,” and whether thattermshouldincludepropyleneglycol,wouldmakeitsubstantiallymoredifficulttoresolvethe infringement issue before me. I cannot determine whether grape flavor and propylene glycol can combine to make a “flavoring agent” without knowing what that term means. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (describing the required two- step process for deciding infringement). The phrase “flavoring agent” is not commonly used by non-scientists, and I must therefore rely on evidence of its “special meaning and usage in the field.” Multiform Desiccants, Inc. v. Medzam, Ltd., 133 F.3d 1473, 1477 (Fed. Cir. 1998); see also Phillips v. AWH Corp., 415 F.3d 1303, 1314 (Fed. Cir. 2005) (“[T]he meaning of a claim term as understood by persons of skill in the art is often not immediately apparent ... .”). Indeed, at the beginning of Azurity’s case-in-chief, its counsel elicited testimony that “[t]he plain and ordinary meaning of a ‘flavoring agent’ would be a mixture of ingredients that imparts flavor to a formulation.” (N.T. 67 (Little).) Such testimony would normally be appropriate for a Mark- man hearing, not trial. See Markman, 517 U.S. at 387; O2 Micro Int’l Ltd. v. Beyond Innovation Tech.Co.,521F.3d1351,1360(Fed.Cir.2008). Azuritythereforetacitlyacknowledgesthatsome amountofclaimconstructionanalysisisnecessarytodecidethiscase. Azurity proposes that I can leave the term “flavoring agent” “[u]nconstrued” and it will default to its “plain and ordinary meaning.” (Proposed Pretrial Order, Ex. 4, ¶ 15.) This argument rests on a false distinction between construction and meaning. Determining “the meaning of a term in the relevant art” is not an alternative to claim construction; it is claim construction. Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 331 (2015); see also Network Com., Inc. v. Microsoft Corp., 422 F.3d 1353, 1359 (Fed. Cir. 2005) (“We construe a claim term as having its ordinary and customary meaning ... .” (quotation marks omitted)). When judges say that a term “require[s] no construction,” they mean that further elaboration is unnecessary because the term is “common parlance” and its meaning is “clear.” Summit 6, LLC v. Samsung Elecs. Co., 802 F.3d 1283, 1291 (Fed. Cir. 2015); see also Schumer v. Laboratory Computer Sys., Inc., 308 F.3d 1304, 1312 (Fed. Cir. 2002) (“These are not technical terms or art, and do not require elaborate interpretation.”). But the term here is “flavoring agent,” which is more technical, and the question about whether it can refer to multiple, possibly flavorless ingredients that also serve non-flavoring functions is somewhat obscure. These issues cannot be resolved without engaging in some sort of claimconstruction. SeeMarkman,517U.S.at386-88. Finally, it would be inappropriate to consider Azurity’s expert testimony on the meaning of “flavoring agent” without also considering the prosecution history evidence Alkem has offered to rebut it. Expert testimony (extrinsic evidence) on claim meaning may not be considered “in a vacuum,” and it is required to view such testimony in “the context of the written description and theprosecutionhistory.”Medrad,Inc.v.MRIDevicesCorp.,401F.3d1313,1319(Fed.Cir.2005). Where“experttestimony...isclearlyatoddswiththeclaimconstructionmandatedbytheclaims themselves, the written description, and the prosecution history,” it is the intrinsic record, not the expert’s testimony, that controls. Phillips v. AWH Corp., 415 F.3d 1303, 1318 (Fed. Cir. 2005) (quotation marks omitted). It would be a peculiar result to enforce the parties’ stipulation that no claimtermsrequireconstructionbyadmittingonly“lessreliable”experttestimonytotheexclusion of more reliable evidence in the patent’s intrinsic record. SkinMedica, Inc. v. Histogen Inc., 727 F.3d1187,1195(Fed.Cir.2013). C. Alkem’sProposedLimitingConstructionBasedontheProsecutionHistory Azuritycontendsthata“flavoringagent”isany“mixtureofingredientsthatimpartsflavor to a formulation.” (N.T. 67 (Little).) Alkem does not propose an alternative, complete defini- tion of “flavoring agent” or dispute that flavoring agents can be mixtures of ingredients. Instead, AlkemadvocatesapartiallimitationonAzurity’sconstruction: asitrelatestoAzurity’sinvention, whatever else a flavoring agent might contain, it cannot contain propylene glycol. Alternatively, Alkem argues that, at the very least, a flavoring agent cannot contain additional, separately added propylene glycol that serves a function other than flavoring. Alkem grounds this limitation in the prosecutionhistoryofthe’948patent. (1) StandardforProsecutionHistoryDisclaimer “[T]he words of a claim are generally given their ordinary and customary meaning,” and there is a “heavy presumption” that the ordinary meaning controls. Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (quotation mark omitted); Housey Pharms., Inc. v. Astrazeneca UK Ltd., 366 F.3d 1348, 1352 (Fed. Cir. 2004). But “[t]he prosecution history can often inform the meaning of the claim language by demonstrating how the inventor understood the invention and whether the inventor limited the invention in the course of prosecution, making the claim scope narrower than it would otherwise be.” Trading Techs. Int’l, Inc. v. eSpeed, Inc., 595 F.3d 1340, 1352 (Fed. Cir. 2010). “For example, a patentee may, through a clear and unmistakable disavowal in prosecution history, surrender certain claim scope to which he would otherwise have anexclusiverightbyvirtueoftheclaimlanguage.”Id.(quotationmarkomitted). “Anyexplanation, elaboration,orqualificationpresentedbytheinventorduringpatentexaminationisrelevant,forthe roleofclaimconstructionistocapturethescopeoftheactualinventionthatisdisclosed,described, andpatented.”Trivascular,Inc.v.Samuels,812F.3d1056,1063(Fed.Cir.2016)(quotationmarks omitted). “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 intheart.”Id.8 (2) Azurity’sRepresentationThatItsClaimedInventionLackedPropylene Glycol I begin with the clearest representation Azurity made to the Examiner that its claimed inventiondidnotcontainpropyleneglycol: ...Palepudisclosesliquidvancomycin-containingcompositionsthatinclude(a) vancomycin ..., (b) a polar solvent comprising propylene glycol, polyethy- lene glycol, or mixtures thereof, (c) lactic acid, ... and optionally (d) a pH adjuster. ... The absence of propylene glycol and polyethylene glycol in the claimedinvention,inpart,distinguishesitfromthecitedreference. Palepu clearly teaches that the polar solvent (comprising propylene glycol, polyethylene glycol, or mixtures thereof) and lactic acid ... are important components in its compositions. ... Palepu emphasizes that it is the interac- tion/combination of its polar solvent (e.g. propylene glycol) and lactic acid ... thatgivesthesolutionslong-termstability. ... ... At least for the reasons stated above, the compositions of Palepu do not fall within the scope of the claimed invention. The claimed invention does not in- cludethepolarsolventsorlacticacidofPalepu. ... (DTX-1004K at 54251-52 (bold text in original, underlining added).) There is no other way to read the underlined statements than as representing that the claimed invention does not contain propylene glycol. The words “absence” and “does not include” are unambiguous. But this does not end the inquiry because Azurity made the above statements in support of a draft claim (claim 8 The parties stipulated that a person of ordinary skill in the art (POSA) would be “a pharmaceu- tical formulator that has either a very high level of education or a lower level of education with a certainamountofexperienceinthefield.”(N.T.54.) 16)thatwaslatercanceled. Thus,Imustfurtherdeterminewhethertheaboveunambiguousrepre- sentations apply to the claims that did issue. See MIT v. Shire Pharms., Inc., 839 F.3d 1111, 1120 (Fed. Cir. 2016) (evaluating whether arguments made in support of some claims applied to other claims). Forthefollowingreasons,Iconcludethattheydo. First, the above arguments were made in support of a draft claim that used the same terms “consisting of” and “flavoring agent” that appear in the issued claims. Cf. MIT, 839 F.3d at 1120 (finding no disclaimer where claim under consideration “did not include the terms” found in the issued claims).9 Second, Azurity itself pointed out that the same argument would support the claims that did issue. With respect to draft claim 20 (which did issue), Azurity referenced the aboverepresentationsandtoldtheExaminer: Asexplainedabove,Paleputeachesthatitspolarsolvents(e.g.propyleneglycol) and lactic acid ... confer its compositions with long-term stability. The claimed invention is an oral vancomycin formulation that is stable for 30 days, and it does not include the polar solvents or lactic acid of Palepu. The skilled artisan would not have had a reasonable expectation of success in producing a stable, oral vancomycin formulation, by combining Palepu and Accord and modifying thesolutionbyremovingthepolarsolventsand/orthelacticacidofPalepu. (DTX-1004Kat54254(underliningof“stable”and“oral”inoriginal,otheremphasisadded).) By referencing its argument with respect to claim 16 (“As explained above”) and repeating its rep- resentation that the claimed invention “does not include” Palepu’s polar solvents (“e.g. propylene glycol”), Azurity clearly and unmistakably represented that the invention did not include propy- leneglycol. Evenstandingalone,thestatementthatAzurity’sinvention“doesnotincludethepolar solventsorlacticacidofPalepu”isaclearandunmistakablerepresentationthattheinventiondoes 9 Technically,draftclaim16used“consistsof,”butthattermissynonymouswith“consistingof.” ShireDev.,LLCv.WatsonPharms.,Inc.,848F.3d981,984(Fed.Cir.2017). notincludepropyleneglycol. Moreover, the Examiner also understood Azurity to be representing that all claims using “consistingof”languageexcludedpropyleneglycol: The instant claims exclude the presence of propylene glycol or polyethylene glycolinviewoftheconsistingoflanguage,andthusovercometheteachingsof Palepuwhichrequiresthepropyleneglycolorpolyethyleneglycoltobepresent withthevancomycinhydrochloride. (DTX-1004O at 54460.) While an examiner’s statement cannot by itself constitute a disclaimer, it maybeconsideredininterpretingtheapplicant’sownstatements. ArendiS.A.R.L.v.GoogleLLC, 882 F.3d 1132, 1136 (Fed. Cir. 2018). The Examiner’s statement shows there was a common un- derstandingthatAzurity’spurposeinaddingthe“consistingof”languagewastoexcludepropylene glycol. It is also evident that Azurity agreed with the Examiner’s interpretation, because Azurity submittedtheclaimsthatwouldbecomethe’948patentshortlyaftertheExaminermadetheabove statement—and, in doing so, repeated the “consisting of” language in its new claims. For these reasons, the above representations by Azurity were a “clear and unmistakable” disclaimer that its inventiondidnotincludepropyleneglycol. Trivascular,812F.3dat1063. In urging that Alkem has not proven disclaimer, Azurity offers three responses, none of which is persuasive. Azurity first asserts that the above representations are more nuanced than they first appear. In Azurity’s view, they conveyed, at most, that the claimed invention lacked so much propylene glycol that it could be called the drug’s “solvent.” Azurity points to the language “[t]he claimed invention ... does not include the polar solvents ... of Palepu” as bearing this interpretation. Although nothing in that sentence references a particular amount of propylene glycol, Azurity argues that it was implied by the word “solvent” and accompanying discussion of Palepu,whichdiddescribeformulationscontainingpropyleneglycolasthedrug’sprimarysolvent. (SeeN.T.294-98(Little).) I disagree with Azurity’s reading of this language. Azurity defined “the polar solvents” as “propylene glycol,” not “a lot of propylene glycol.” Azurity’s reading also fails to explain why it further represented that there was an “absence of propylene glycol ... in the claimed invention,” words that are not susceptible to an interpretation that only a certain quantity of propylene glycol wasdisclaimed. Azurity’s contention that it only disclaimed enough propylene glycol to make a solvent is also belied by the lack of any mention of how much propylene glycol that would be. Even at trial, Azurity’s expert could not say how much propylene glycol it takes to make a solvent. (N.T. 117- 18 (Little).) Palepu itself discloses formulations containing widely varying amounts of propylene glycol—all the way down to 1.2%. (N.T. 330-34; PTX-188 at 8534, [0054].) Given that the ExaminerhadjustrejectedAzurity’sproposednegativelimitationon“suspendingagents”because it was unclear what that limitation excluded, it would make little sense for the Examiner to then allow Azurity to distinguish Palepu based on an undefined notion of enough propylene glycol to becalledasolvent. The dialogue between Azurity and the Examiner regarding negative limitations is also in- structive. Although I agree with Azurity that arguments in support of negative-limitation claims cannot by themselves be disclaimers because negative limitations do not appear in any asserted claim, this dialogue nevertheless shows that Azurity and the Examiner had long been discussing the possibility of distinguishing Palepu based on the presence or absence of propylene glycol, not any particular amount of it. Azurity’s view thus has to be that at some point the dialogue silently switchedtobeingaboutaparticularamountofpropyleneglycol,withoutanyoneeversayingwhat that amount was. That interpretation is not plausible. For these reasons, I disagree with Azurity’s readingthatonlyacertainquantityofpropyleneglycolwasdisclaimed. Azurity’s second proposed reading of the prosecution history is that it did not disclaim propylene glycol by itself, only propylene glycol in conjunction with lactic acid. In support, Azu- ritypointstothebelowstatement: Palepu emphasizes that it is the interaction/combination of its polar solvent (e.g. propylene glycol) and lactic acid (or the lactate molecule used in some embodiments)thatgivesthesolutionslong-termstability. (DTX-1004 at 54251.) To the extent Azurity is suggesting that it might have been possible to distinguish Palepu more narrowly because Palepu required certain ingredients to be present in its formulations, “the scope of surrender is not limited to what is absolutely necessary to avoid a prior art reference; patentees may surrender more than necessary.” Tech. Properties Ltd. LLC v. Huawei Techs. Co., 849 F.3d 1349, 1359 (Fed. Cir. 2017). “An applicant’s argument that a prior art reference is distinguishable on a particular ground can serve as a disclaimer of claim scope even if the applicant distinguishes the reference on other grounds as well.” SpeedTrack, Inc. v. Amazon.com, 998 F.3d 1373, 1380 (Fed. Cir. 2021). Azurity may well have pointed to lactic acid as a difference between its invention and Palepu’s, but that does not change the fact that Azurity unambiguouslystatedthatitsinventiondidnotcontainpropyleneglycol. Finally,AzurityarguesthatIshouldconsideritslaterstatementtotheExaminerthatit“did not disclaim propylene glycol” and “reserve[d] the right to claim propylene glycol in the instant and future cases in this patent family.” (DTX-1007B at 61030.) This statement is insufficient to overcome Azurity’s clear and unambiguous disclaimer, nor does it render Azurity’s disclaimer amenableto“multiplereasonableinterpretations.”Theabovestatement,whichwasnotmadeinthe ’400applicationoranancestortoit,waspresentedafterthislawsuitbegan,aftertheExaminerhad told Azurity that language materially identical to the claims of the ’948 patent would be allowed, and after Alkem had provided its Paragraph IV notice to Azurity regarding the ANDA in this case.10 The statement does not reference the claims of the ’948 patent, does not mention their “consistingof”language,doesnotamendtheclaims,anddoesnotasktheExaminertodoanything. In fact, the statement does not even assert that any claims then under consideration encompassed propylene glycol, just that Azurity “reserve[d] the right” to submit such claims if it so chose. And Azurity’sstatementcertainlydidnotputtheExaminerorthepubliconnoticethatAzurityplanned to use the “flavoring agent” ingredient to undermine its representation that its invention excluded propylene glycol. Azurity’s disclaimer of propylene glycol remains clear and unmistakable. With respecttoAzurity’salternativeargumentthattheabovestatementshowsits“goodfaithbelief”that it did not disclaim propylene glycol, (Azurity’s Post-Trial Brief at 25 n.14,) “good faith belief” is not the standard for evaluating disclaimer, which is an “objective” inquiry. SkinMedica, Inc. v. HistogenInc.,727F.3d1187,1203(Fed.Cir.2013). For these reasons, I conclude that Azurity clearly and unmistakably represented to the Examinerthatitsinventionlackedpropyleneglycol. D. ApplicationtoAlkem’sANDA Having determined that Azurity disclaimed propylene glycol in its invention, deciding in- fringementbecomesstraightforward. Alkem’sANDAincludes1milligrampermilliliterofpropy- lene glycol. (Undisputed Facts ¶ 56; N.T. 166 (Forrest).) Therefore, Alkem’s ANDA does not infringe any asserted claim. In light of my previous findings, Azurity does not seriously dispute thisconclusion. (SeeN.T.262(“THECOURT:IfIfindthatyoudisclaimPG,canyoustillwinthe 10In closing arguments, Azurity acknowledged that it made this statement in response to Alkem’s noninfringementposition. (N.T.4/17/23at37:24-38:6.) case? [Azurity’sCounsel]: No,becausetheyhavePGintheproduct,soIagreewiththat.”).) Azurityneverthelessarguesthatitsdisclaimerdoesnotapplytopropyleneglycolcontained withina“flavoringagent”becausethepartiesstipulatedthat“[s]uitableflavoringagentsforusein theAssertedClaimsincludeflavoringagentswithorwithoutpropyleneglycol.”(UndisputedFacts ¶ 92.) As I understand this argument, Azurity reads “suitable ... for use in the Asserted Claims” to mean “infringing” and asserts that because there exists some, unspecified infringing product containingpropyleneglycol,disclaimermustnotapply. Azurity’s argument regarding the parties’ stipulation is unpersuasive. The stipulation says nothing about whether Alkem’s ANDA contains a flavoring agent with propylene glycol, and by its terms acknowledges that there are also flavoring agents without propylene glycol. Moreover, even if there does exist an unknown infringing flavoring agent with propylene glycol, Azurity at least disclaimed using the term “flavoring agent” to encompass additional propylene glycol, not added as part of a flavoring agent, that does not contribute to the flavor of the drug. Any contrary conclusionwouldbeincompatiblewithAzurity’srepeatedstatementstotheExaminer.11 Finally, I note that: (1) Alkem’s “co-solvent” propylene glycol is added separately from the ANDA’s grape flavor; (2) Azurity failed to prove the “co-solvent” propylene glycol has any perceptibleeffectontheANDA’staste;and(3)Azurityfailedtoprovethatthe“co-solvent”propy- lene glycol does not function as a co-solvent for the parabens. Azurity’s disclaimer of propylene glycol therefore applies to the “co-solvent” propylene glycol, irrespective of whether there might 11Byanalogy,assumingamixtureoftenpartswatertoonepartlemonadecouldbecalled“lemon- ade” or even “just lemonade,” it would be inaccurate to call it “just lemonade and not water.” Likewise,AzurityrepresentedtotheExaminerthatitsinventionwasjustthelistedingredientsand notpropyleneglycol. existother,unspecifiedinfringingflavoringagentsthatcontainpropyleneglycol.12 VI. CONCLUSION Forthereasonssetforthabove,IconcludethatAzurityhasnotproven,byapreponderance of the evidence, that Alkem’s ANDA meets the “consisting of” limitation of any asserted claim, and,consequently,Alkem’sANDAdoesnotinfringeanyassertedclaim. Anappropriateorderfollows. 12Itisunnecessarytodiscusstheparties’stipulationthatAlkem’sANDAproductisa“non-sterile stableliquidformulation”becausethescopeofthistermisimmaterial. (ECFNo. 110.) Azuritycontendsthattwoadditionalfactsarerelevanttotheinfringementinquiry,butitisunclear how these facts relate to the asserted claim limitations. First, Azurity stresses that the “grape fla- vor” propylene glycol and the “co-solvent” propylene glycol in Alkem’s ANDA are “chemically identical” and both interact with the grape-flavored chemicals. (N.T. 78-79 (Little); N.T. 25 (Azu- rity’scounsel).) Butifarecipecallsforonecupofwater,addingtwocupsofwaterisnotfollowing therecipe,evenifitislaterimpossibletotellwhichcupwaswhich. Second,Azuritypointsoutthat the amount of “co-solvent” propylene glycol in Alkem’s ANDA is similar to an amount of a sub- stance that could be added as a “flavoring agent,” as indicated by the patent’s specification. (N.T. 137 (Little).) But the claim term is “flavoring agent,” not “any ingredient in an amount similar to aflavoringagent.”Becausethe“co-solvent”propyleneglycolinAlkem’sANDAisnotaflavoring agent, it does not prove infringement to show that a flavoring agent could have been added in a similaramount.

Document Info

Docket Number: 1:20-cv-01094

Filed Date: 5/4/2023

Precedential Status: Precedential

Modified Date: 6/21/2024