Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd.

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
______________________
T UNG O N K ONG, Wilson, Sonsini, Goodrich & Rosati,
PC, San Francisco, CA, argued for plaintiff-appellant. Also
represented by WENDY L. D EVINE; K ELSEY CURTIS ,
RICHARD T ORCZON, Washington, DC.
ALAN HENRY P OLLACK, Windels Marx Lane & Mitten-
dorf, LLP, Madison, NJ, argued for defendant-appellee.
Also represented by K IERSTEN AMANDA F OWLER, J OSHUA I.
MILLER.
______________________
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Before M OORE, 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.
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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
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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).
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D ISCUSSION
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.
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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
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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
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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,
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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
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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
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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
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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
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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.
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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.
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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.
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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
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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.
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