Bial - Portela & CA., S.A. et al v. Torrent Pharmaceuticals Ltd. et al

Filing 63

MEMORANDUM ORDER re: Claim Construction Signed by Judge Colm F. Connolly on 10/17/2019. Associated Cases: 1:18-cv-00279-CFC et al.(nmf)

IN THE UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF DELAWARE
BIAL - PORTELA & CA S.A., BIAL HOLDING, S.A., and SUNOVION
PHARMACEUTICALS INC.,
Plaintiffs,

v.

Civil Action No. 18-279-CFC

TORRENT PHARMACEUTICALS
LTD. and TORRENT PHARMA INC.,
Defendants.
BIAL - PORTELA & CA S.A., BIAL HOLDING, S.A., and SUNOVION
PHARMACEUTICALS INC.,
Plaintiffs,

v.

Civil Action No. 18-304-CFC

ALKEM LABORATORIES LIMITED
and S&B PHARMA, INC.,
Defendants.
BIAL - PORTELA & CA S.A., BIAL HOLDING, S.A., and SUNOVION
PHARMACEUTICALS INC.,
Plaintiffs,

v.

Civil Action No. 18-312-CFC

LUPIN LIMITED and LUPIN
PHARMACEUTICALS, INC.,
Defendants.

BIAL - PORTELA & CA S.A., BIAL HOLDING, S.A., and SUNOVION
PHARMACEUTICALS INC.,
Plaintiffs,

v.

Civil Action No. 18-336-CFC

JUBILANT LIFE SCIENCES
LIMITED, JUBILANT PHARMA
LIMITED, JUBILANT GENERICS
LIMITED, JUBILANT LIFE
SCIENCES (USA) INC., and
JUBILANT CADISTA
PHARMACEUTICALS INC.,
Defendants.
BIAL - PORTELA & CA S.A., BIAL HOLDING, S.A., and SUNOVION
PHARMACEUTICALS INC.,
Plaintiffs,
v.

Civil Action No. 18-341-CFC

DR. REDDY'S LABORATORIES,
LTD. and DR. REDDY'S
LABORATORIES, INC.,
Defendants.

11

BIAL - PORTELA & CA S.A., BIAL HOLDING, S.A., and SUNOVION
PHARMACEUTICALS INC.,
Plaintiffs,

v.

Civil Action No. 18-342-CFC

HETERO LABS LIWTED, HETERO
LABS Lll\11TED UNIT-V, and
HETERO USA INC.,
Defendants.
BIAL - PORTELA & CA S.A., BIAL HOLDING, S.A., and SUNOVION
PHARMACEUTICALS INC.,
Plaintiffs,
Civil Action No. 18-382-CFC

V.

APOTEX INC. and APOTEX CORP.,
Defendants.
BIAL - PORTELA & CA S.A., BIAL HOLDING, S.A., and SUNOVION
PHARMACEUTICALS INC.,
Plaintiffs,

v.

Civil Action No. 18-775-CFC

SPH SHANGHAI ZHONGXI
PHARMACEUTICAL CO., LTD.,
Defendant.

111

MEMORANDUM ORDER
Before me is the matter of claim construction of terms found in six patents
asserted in this case: U.S. Patent Nos. 5,753,646 ("the #646 patent"), 8,372,431
("the #431 patent"), 9,206,135 ("the #135 patent"), 9,566,244 ("the #244 patent"),
9,643,929 ("the #929 patent"), and 9,750,747 ("the #747 patent). Oral argument
regarding claim construction was held on October 11, 2019.
At the heart of this Hatch-Waxman case is Aptiom®, an anti-epileptic drug
approved by the Food and Drug Administration (FDA) for the treatment of partialonset seizures. Plaintiffs Bial-Portela & CA S.A. and Bial-Holding, S.A.
developed Aptiom® and own the asserted patents. Plaintiff Sunovion
Pharmaceuticals is the holder of the Aptiom® New Drug Application and the
exclusive licensee of the asserted patents, all of which Sunovion listed in the
FDA's Orange Book. The asserted patents cover the active pharmaceutical
ingredient in Aptiom®, eslicarbazepine acetate; pharmaceutical compositions and
formulations containing eslicarbazepine acetate; and methods of treatment in
certain patient subpopulations using eslicarbazepine acetate.
Defendants are eight manufacturers that filed Abbreviated New Drug
Applications (ANDAs) seeking FDA approval to market generic eslicarbazepine
acetate tablets prior to the expiration of the asserted patents. Plaintiffs allege that
Defendants' filing of their respective ANDAs constitute infringement under 35

U.S.C. § 271(e).

TERM A:

"stereoisomer" in claim 1 of the #646 patent
1. Plaintiffs' proposed construction: "the compound having the same
molecular formula, but being arranged differently in space"
2. Defendants' proposed construction: "either S(-) or R(+)
enantiomer of the recited compounds in the genus"
3. Court's Construction: "the compound having the same
molecular formula, but being arranged differently in space"

Claim 1 of the #646 patent recites: "A compound of general formula I, or

stereoisomer thereof, wherein: ... R is hydrogen, alkyl, aminoalkyl, halogenalkyl,
aralkyl, cycloalkyl, cycloalkylalkyl, alkoxy, aryl or pyridyl ...." #646 patent at
claim 1 (8 :50-66). I construe "stereoisomer" in claim 1 of the #646 patent as "a
compound having the same molecular formula, but being arranged differently in
space" because that is the term's plain and ordinary meaning to a person of
ordinary skill in the art (POSITA) at the time of the invention and the intrinsic
record does not otherwise define or limit the term.
A court should construe claim terms according to the plain and ordinary
meaning that the term would have to a POSITA when read in the context of the
specification and prosecution history. Thorner v. Sony Comput. Entm 't Am. LLC,
669 F.3d 1362, 1365 (Fed. Cir. 2012). "There are only two exceptions to this
general rule: 1) when a patentee sets out a definition and acts as his own
lexicographer, or 2) when the patentee disavows the full scope of the claim term

,

either in the specification or during prosecution." Id. In either event, the
2

lexicography or disavowal must be clear and unmistakable. See id. at 1367-68.
Here, the claims, written description, and prosecution history do not specifically
define or limit the meaning of the term stereoisomer. Thus, the term must be
construed according to its plain and ordinary meaning.
The plain and ordinary meaning of the term stereoisomer to a POSITA at the
time of the invention was "a compound having the same molecular formula, but
being arranged differently in space." According to Organic Chemistry, isomers are
"different compounds that have the same molecular formula" and stereoisomers
are "[t]he particular kind of isomers that are different from each other only in the
way the atoms are oriented in space (but are like one another with respect to which
atoms are joined to which other atoms)." Robert Thornton Morrison & Robert
Neilson Boyd, Organic Chemistry, 125 (6th ed. 1992). (The parties agree that it is
appropriate for me to rely on this definition set forth in Organic Chemistry. See
D.I. 58 1 at 6; Markman Hr'g Tr. 24:2-9.)
Instead of using the plain and ordinary meaning, Defendants seek to limit the
term stereoisomer to only the S(-) or R(+) enantiomers of the recited compounds.
D.I. 58 at 5. Nothing in the specification or prosecution history, however, limits or
specially defines the term to include only the S(-) and R(+) enantiomers of the
compound. Instead, the written description supports a broader reading of the term.

1

All citations are to the docket for C.A. No. 18-0279 unless stated otherwise.
3

It states: "The invention ... relates to new compounds of general formula I,
including all possible stereoisomers ...." #646 patent at 1:36-39 (emphasis
added). Moreover, Defendants' proposed construction would exclude
embodiments of claim 1: specifically, compounds 16 and 31 of claim 2. D.I. 58 at
8 (citing #646 patent at 9:41-42, 10:12-13). An interpretation that excludes a
preferred embodiment "is rarely, if ever, correct and would require highly
persuasive evidentiary support" that does not exist here. Vitronics Corp. v.

Conceptronic, Inc., 90 F.3d 1576, 1583 (Fed. Cir. 1996).
Defendants' argument relies, in part, on the figure in claim 1 that follows the
word "thereof." See #646 patent at claim 1 (8:53-63). Defendants claim that the
wavy line in the figure identifies the location of the chiral center of the
stereoisomers. D.I. 58 at 10. In Defendants' view, the patentees "limited
themselves to [the] set of stereoisomers located at the chiral center, not all possible
stereoisomers." Id. Nothing in the text of the written description or claims,
however, states that the wavy line is the only potential location of the chiral center.
Finally, Defendants assert that the prosecution history supports its
construction. Claim 1 of the #646 patent originally recited "[c]ompounds of
general formula I, including all possible stereoisomers." 0.1. 58 at 10 (citing D.I.
59 at Appxl3 l). That claim language was rejected by the patent examiner, and the
patentees amended the claim to recite "[a] compound of general formula I, or
4

stereoisomer thereof." Id. (citing D.I. 59 at Appx138).
The prosecution history can inform the claim construction analysis. Phillips

v. AWH Corp., 415 F.3d 1303, 1315 (Fed. Cir. 2005). "Yet because the
prosecution history represents an ongoing negotiation between the PTO and the
applicant, rather than the final product of that negotiation, it often lacks the clarity
of the specification and thus is less useful for claim construction purposes." Id. at
131 7. Thus, "it is inappropriate to limit a broad definition of a claim based on
prosecution history that is itself ambiguous." Inverness Med. Switz. GmbH v.

Warner Lambert Co., 309 F.3d 1373, 1382 (Fed. Cir. 2002).
Here, the prosecution history is too ambiguous to justify reliance on it in
construing the disputed term. It is not clear if the change to "a compound, or
stereoisomer thereof' was made for grammatical reasons (as Plaintiffs contend), to
limit the types of stereo isomers claimed for validity purposes (as Defendants
contend), or for some other reason. Without a clear explanation of the amendment,
the change does not limit the plain meaning of the term.
Furthermore, the new language of the amended (and final) claim-"a
compound ... or stereoisomer thereof'--does not limit the term stereoisomers to
two kinds of enantiomers. The language "a compound, or stereoisomer thereof'
would cover multiple types of stereoisomers based on the plain meaning of those
words.
5

Because the written description and prosecution history do not unmistakably
limit the scope of the term "stereoisomers," I construe the term according to its
plain and ordinary meaning to a POSITA at the time of the invention. That plain
and ordinary meaning is "the compound having the same molecular formula, but
being arranged differently in space."
TERM B

"10-acetoxy-10, 11-dihydro-SH-dibenz/b,f/azepine-5carboxamide" in claim 2 of the #646 patent
1. Plaintiffs' proposed construction: "licarbazepine acetate, including
R-licarbazepine acetate, S-licarbazepine acetate, or a mixture ofRlicarbazepine acetate and S-licarbazepine acetate in any
proportion"
2. Defendants' proposed construction: "licarbazepine acetate, i.e. a
racemic mixture consisting of the S(-)-10-acetoxy-10, 11-dihydroSH-dibenz/b,f/azepine-5-carboxamide and R(+)-1O-acetoxy-10,
11-dihydro-SH-dibenz/b,f/azepine-5-carboxamide individual
enantiomers"
3. Court's Construction: "licarbazepine acetate, including RIicarbazepine acetate, S-licarbazepine acetate, or a mixture of
R-licarbazepine acetate and S-Iicarbazepine acetate in any
proportion"

The parties agree that 10-acetoxy-10, 11-dihydro-SH-dibenz/b,f/azepine-5carboxamide is the compound licarbazepine acetate. They dispute, however,
whether the claimed compounds include the R-enantiomer, the S-enantiomer, and
mixtures thereof in any proportion (as Plaintiffs contend) or only racemic mixtures
of the R- and S-enantiomers (as Defendants contend).
I construe "1O-acetoxy-10, 11-dihydro-SH-dibenz/b,f/azepine-5carboxamide" as "licarbazepine acetate, including R-licarbazepine acetate, S6

licarbazepine acetate, or a mixture ofR-licarbazepine acetate and S-licarbazepine
acetate in any proportion." Nothing in the intrinsic record limits 10-acetoxy-10,
11-dihydro-5H-dibenz/b,f/azepine-5-carboxamide to a specific form. Thus, I
construe the term to include all stereoisomeric forms in accordance with its plain
and ordinary meaning in the context of the written description and prosecution
history.
The language of claim 2 and the written description of the #646 patent show
that the claimed licarbazepine acetate in claim 2 includes all of its stereoisomers,
not just its racemic stereoisomer. Claim 2 recites: "A compound as defined in
claim 1 which is: (1) 1O-acetoxy-10, l 1-dihydro-5H-dibenz/b,f/azepine-5carboxamide ...." #646 patent at claim 2 (9:7-9). And claim 1 recites: "A
compound of general formula I, or stereoisomer thereof ...." Id. at claim 1 (8:5051 ). Thus, claim 1 recites a compound and all of its stereoisomeric forms and
claim 2 lists preferred compounds of the compound defined in claim 1.
Furthermore, the written description of the #646 patent states: "The invention ...
relates to new compounds of general formula I, including all possible
stereoisomers ...." Id. at 1:36-39 (emphasis added). Finally, Example 4
describes a method of preparing (+)-10-acetoxy-10, 11-dihydro-5Hdibenz/b,f/azepine-5-carboxamide, and (+)-1O-acetoxy-10, 11-dihydro-5Hdibenz/b,f/azepine-5-carboxamide is not a racemic mixture. Id. at 6:52-54; D.I. 58
7

at 20, 22. Claim terms are normally not interpreted "in a way that excludes
disclosed examples in the specification." Verizon Se11Js. Corp. v. Vonage Holdings
Corp., 503 F.3d 1295, 1305 (2007).

Defendants assert that the prosecution history shows that the patentee
disclaimed the S- and R-enantiomers because, in a declaration submitted to the
United Stated Patent and Trademark Office, the patentee identified the S- and Renantiomers with the nomenclature "S(-)" and "R(+)" and that nomenclature does
not appear in the disputed term in claim 2. D.I. 58 at 22-23. I disagree. The
prosecution history cannot be used to limit the scope of a claim unless it shows that
the patentee "clearly disavowed" the claim scope during prosecution. IMS Tech.,
Inc. v. Haas Automation, Inc., 206 F.3d 1422, 1439 (Fed. Cir. 2000). Denoting the

S- and R-enantiomers during prosecution and not in the claim language is not a
clear disavowal of claim scope that limits the compound to the S- and Renantiomers. The patentee's failure to use the S(-) and R(+) nomenclature could
also be interpreted as showing that the patentee intended the claimed compound to
include more than just the S- and R-enantiomers instead of excluding those
stereoisomeric forms. Furthermore, Defendants' own reasoning would exclude
Defendants' construction. Defendants insist that I construe the disputed compound
term as racemic only, but in the same declaration Defendants cite, the patentee also
identified racemic licarbazepine acetate with the term "racemic" in front of the

8

compound name, see D.I. 59 at Appx 147, and the term racemic does not appear in
the disputed term in claim 2, see #646 patent at claim 2. Thus, using Defendants'
logic, because the term racemic does not appear before the compound term in
dispute, the compound cannot include the racemic form.
The Federal Circuit has required "convincing intrinsic evidence [to confine]
otherwise-unrestricted claims to racemic mixtures." Sumitomo Dainippon Pharma
Co. v. Emcure Pharms. Ltd., 887 F.3d 1153, 1158 (Fed. Cir. 2018). Yet here,
nothing in the intrinsic record supports limiting the claim to racemic mixtures. The
term "racemic" does not appear in the #646 patent. See #646 patent. And the
prosecution history does not show that the compound is limited to racemic
mixtures. Because the patent does not limit the licarbazepine acetate compound to
particular stereoisomeric forms, I construe the disputed term to include the S-and
R-enantiomers and mixtures of those two enantiomers in any proportion.

TERM C

"licarbazepine acetate" in claims 8, 12, and 13 of the #431 patent
and claims 1 and 2 of the #244 patent
1. Plaintiffs' proposed construction: "R-licarbazepine acetate, Slicarbazepine acetate, or a mixture ofR-licarbazepine acetate and
S-licarbazepine acetate in any proportion"
2. Defendants' proposed construction: "the individual R- and Sisomers, the racemic mixture of the isomers, and also non-racemic
mixtures of the R- and S-isomers in any proportion, where 'Rlicarbazepine acetate' means the R-isomer in substantially pure
form, i.e., at least about 90% pure, preferably at least about 95%
pure, more preferably at least about 98% pure, and most preferably
at least about 99% pure; and 'eslicarbazepine acetate' or 'Slicarbazepine acetate' means S-isomer in substantially pure form,
9

i.e., at least about 90% pure, preferably at least about 95% pure,
more preferably at least about 98% pure, and most preferably at
least about 99% pure"
3. Court's Construction: "the individual R- and S-isomers, the
racemic mixture of the isomers, and also non-racemic mixtures
of the R- and S-isomers in any proportion"
I construe the term "licarbazepine acetate" as "the individual R- and Sisomers, the racemic mixture of the isomers, and also non-racemic mixtures of the
R- and S-isomers in any proportion" because the common written description of
the #431 patent and the #244 patent expressly defines the term licarbazepine
acetate using that definition.
A patent applicant "may choose to be his own lexicographer ... as long as
the special definition of the term is clearly stated in the patent specification or file
history." Vitronics, 90 F.3d at 1582. Here, the patentee clearly defined
licarbazepine acetate in the written description of the relevant patents. The
common written description of the #431 and #244 patents states: "In this
specification the expression 'licarbazepine acetate' encompasses the individual Rand S-isomers, the racemic mixture of the isomers, and also non-racemic mixtures
of the R- and S-isomers in any proportion." #431 patent at 4:49-52; #244 patent at

4:57-61.
Defendants ask me to add to the term's construction additional text from the
paragraph in the written description containing the definition just quoted. That
paragraph reads as follows:

10

Licarbazepine acetate is optically active, existing in two
enantiomeric forms. In this specification the expression
'licarbazepine acetate' encompasses the individual R-and
S-isomers, the racemic mixture of the isomers, and also
non-racemic mixtures of the R- and S- isomers in any
proportion. In this specification "R-licarbazepine acetate"
means the R-isomer in substantially pure form, i.e. at
least about 90% pure, preferably at least about 95% pure,
more preferably at least about 98% pure, and most
preferably at least about 99% pure. In this specification
"eslicarbazepine acetate" or "S-licarbazepine acetate"
means S-isomer in substantially pure form, i.e., at least
about 90% pure, preferably at least about 95% pure, more
preferably at least about 98% pure, and most preferably
at least about 99% pure."
#431 patent at 4:48-61; #244 patent at 4:56-5:3. Defendants ask me to
construe "licarbazepine acetate" as including the last two sentences of this
paragraph.
While the claims should be construed in the context of the entire patent and
prosecution history, the last two sentences in the paragraph do not narrow the
definition of licarbazepine acetate but instead provide definitions for two different
terms-"R-licarbazepine acetate" and "eslicarbazepine acetate." The structure of
the paragraph shows that each of these sentences sets forth an individual definition,
not a further limitation on the original term licarbazepine acetate. The additional
sentences define two embodiments of licarbazepine acetate-R-licarbazepine
acetate and S-licarbazepine acetate-with purity limitations. The parties only
dispute the construction of licarbazepine acetate, not R-licarbazepine acetate and
11

eslicarbazepine acetate. Thus, the definitions of those embodiments are not
relevant here.
In short, I construe licarbazepine acetate as "the individual R- and Sisomers, the racemic mixture of the isomers, and also non-racemic mixtures of the
R- and S-isomers in any proportion" because that is how the written description of
the patents defines the term.

TERM D

"(S)-(-)-10-acetoxy-10, 11-dihydro-SH-dibenz/b,f/azepine-5carboxamide having a chemical purity of at least about 99.96%"
and "having a chemical purity of (S)-( -)-10-acetoxy-10, 11dihydro-SH-dibenz/b,f/azepine-5-carboxamide of about 99.96%"
in claims 1 and 2 of the #929 patent and claims 2 and 9 of the #135
patent
1. Plaintiffs' proposed construction: "eslicarbazepine acetate having a
chemical purity of at least about 99 .96%" and "having a chemical
purity of the eslicarbazepine acetate of about 99 .96%"
2. Defendants' proposed construction: "eslicarbazepine acetate
obtained by a process of reduction of oxcarbazepine using a
ruthenium catalyst and having a chemical purity of at least about
99 .96%" and "eslicarbazepine acetate obtained by a process of
reduction of oxcarbazepine using a ruthenium catalyst and having
a chemical purity of about 99 .96%"
3. Court's Construction: "eslicarbazepine acetate obtained by a
process of reduction of oxcarbazepine using a catalyst and
having a chemical purity of at least about 99.96%" and
"eslicarbazepine acetate obtained by a process of reduction of
oxcarbazepine using a catalyst and having a chemical purity of
about 99.96%"

The parties agree that (S)-(-)-10-acetoxy-10,l l-dihydro-SHdibenx/b,f/azepine-5-carboxamide is eslicarbazepine acetate. Defendants argue,

12

however, that the disputed term contains a process limitation-Le., that the
eslicarbazepine acetate must be "obtained by a process of reduction of
oxcarbazepine using a ruthenium catalyst." Plaintiffs argue that the disputed
claims recite compounds and compositions only. 2
I construe "(S)-(-)-10-acetoxy-10, 11-dihydro-5H-dibenz/b,f/azepine-5carboxamide having a chemical purity of at least about 99 .96%" as
"eslicarbazepine acetate obtained by a process of reduction of oxcarbazepine using
a catalyst and having a chemical purity of at least about 99 .96%" because the
written description makes clear that the claims include process limitations.
Generally, words of a claim are given their "ordinary and customary
meaning as understood by a [POSITA] when read in the context of the
specification and prosecution history." Thomer, 669 F.3d at 1365. "There are
only two exceptions to this general rule: 1) when a patentee sets out a definition
and acts as his own lexicographer, or 2) when the patentee disavows the full scope
of the claim term either in the specification or during prosecution." Id.
Here, although the claims cover compounds on their face, the patentee has
disavowed the full scope of the claim because the written description

2

Although claims 2 and 9 of the #135 patent claim compounds and claims 1 and 2
of the #929 patent claim compositions, the parties have agreed that there is no
difference between the terms compound and composition in the pharmaceutical
context. Tr. 57:16-19. Thus, I will use those terms interchangeably.
13

unambiguously shows that the claimed invention is a process, not a compound.
Although product claims are generally not limited to their methods of manufacture,
"process steps can be treated as part of a product claim if the patentee has made
clear that the process steps are an essential part of the claimed invention" and thus
has disavowed the full scope of the product claim. Andersen Corp. v. Fiber

Composites, LLC, 474 F.3d 1361, 1375 (Fed. Cir. 2007). Here, throughout the
written description of the asserted patents, the invention is exclusively described as
a method or process for the preparation of eslicarbazepine acetate. "When a patent
... describes the features of the 'present invention' as a whole, this description
limits the scope of the invention." Verizon Servs. Corp., 503 F.3d at 1308. The
patents' shared Field of the Invention states that "[t]he present invention relates to
a process for the asymmetric catalytic reduction of oxcarbazepine." #135 patent at
1: 18-22; #929 patent at 1:20-24. The title of both patents is "Asymmetric
Catalytic Reduction of Oxcarbazepine." #135 patent at Title; #929 patent at Title.
The shared Abstract states: "A process for preparing [eslicarbazepine acetate or Rlicarbazepine acetate] by reduction of oxcarbazepine in the presence of a catalyst
and a hydride source is disclosed." #135 patent at Abstract; #929 patent at
Abstract. And finally, the shared Summary and Detailed Description of the
Invention describes exclusively a process or method for preparing eslicarbazepine
acetate through reduction of oxcarbazepine in the presence of a catalyst and a
14

hydride source. See #135 patent at Summary of the Invention, Detailed
Description of the Invention; #929 patent at Summary of the Invention, Detailed
Description of the Invention.
The intrinsic evidence here is similar to that in Forest Laboratories, LLC v.

Sigmapharm Laboratories, LLC, 918 F.3d 928, 933 (Fed. Cir. 2019). In Forest
Labs., the Federal Circuit read a method into a claim that was a composition claim
on its face. Id. The Court cited language in the written description describing the
invention as a whole and the title of the patent as proof that the claims included the
method. Id.
Plaintiffs rely on AstraZeneca LP v. Breath Ltd., 542 F. App'x 971 (Fed.
Cir. 2013) in support of their argument that process limitations should not be read
into the compound claims at issue here. D.I. 58 at 37, 53. In AstraZeneca,
however, the written description of the patent disclosed three separate concepts: a
process, products, and methods of use. 542 F. App'x at 976. Here, the written
description only discloses a process.
Additionally, the written description of the patents describes the prior art
problem as a problematic process not a problematic compound, further showing
that the claimed invention is a process, not a compound. See Honeywell Int'/, Inc.

v. ITT Indus., Inc., 452 F.3d 1312, 1318 (Fed. Cir. 2006) ("The written
description's detailed discussion of the prior art problem addressed by the patented
15

invention, viz., leakage of non-metal fuel filters in EFI systems, further supports
the conclusion that the fuel filter is not a preferred embodiment, but an only
embodiment."). The written description characterizes the claimed invention as an

improved method for the preparation of eslicarbazepine acetate. See, e.g., #135
patent at 2:60-64. The Background of the Invention criticizes a prior art process
for using high amounts of a ruthenium catalyst that resulted in a high residual level
of ruthenium. #135 patent at 2:9-27; #929 patent at 2:11-30. It further criticizes
the prior art process as not "economically viable for large-scale manufacturing
purposes." #135 patent at 2:27-32; #929 patent at 2:10-35. The patent's solution
to the prior art problem is an "improved method" that results in low residual
ruthenium in the resulting product and is "conveniently operable on a large-scale."

#135 patent at 4:5-10; #929 patent at 4:10-16. Thus, the prior art problem
addressed by the patented invention was the disparaged process, not the high
ruthenium content or low purity of the resulting eslicarbazepine.
Plaintiffs argue that because other claims in the #135 patent expressly recite
product-by-process claims and claims 2 and 9 of the same patent do not, claims 2
and 9 must not claim a process. (They also assert that this argument applies to
claims 1 and 2 of the #929 patent even though the #929 patent has no product-byprocess claims.) In other words, Plaintiffs assert the doctrine of claim
differentiation. That doctrine holds that "different words or phrases used in

16

separate claims are presumed to indicate that the claims have different meanings
and scope." Andersen, 474 F.3d at 1369. If"the absence of such difference in
meaning and scope would make a claim superfluous, [then] the difference between
claims is significant." Id. at 1369. Plaintiffs argue that because the word "process"
is used in certain claims of the # 13 5 patent and not in claims 2 and 9 of the same
patent, claims 2 and 9 must have a different meaning.
A presumption arising from the doctrine of claim differentiation can be
overcome by "powerful evidence to the contrary" in the written description. Id. at
1370. For example, in Forest Labs., the Federal Circuit read an administration
method into a claim even though another claim in the patent expressly claimed that
same method, because of strong evidence in the written description showing that
the claim included the method. 918 F.3d at 932. In this case, the written
description is replete with descriptions of the invention as a process and devoid of
any description of the invention as a compound. It thus constitutes powerful
evidence that the claimed invention is a process as opposed to a compound, and it
overcomes any presumption arising from the doctrine of claim differentiation.
Furthermore, the claims that use process language-claims 4, 7, and 10 of the #135
patent-describe processes that are more limited than the process implied in claims
2 and 9. Thus, construing claims 2 and 9 as having a process limitation would not
render claims 4, 7, and 10 superfluous.
17

The written description's repeated and unequivocal descriptions of the
invention as a method and process also defeat Plaintiffs' argument that the
applicant's cancellation of product-by-process claims and addition of purity claims
during the prosecution history shows that the inventors intended to remove the
process limitations and end up with purely composition claims.
While cancelling of the product-by-process claims might suggest that the
inventors intended to change the claims to compound claims, the prosecution
history does not clearly indicate their intentions, whereas the written description
unambiguously states that the "present invention" is a process. An unclear
prosecution history "cannot contradict ... clear statements in the specification
describing the invention more narrowly." Honeywell, 452 F.3d at 138-39.
Finally, Defendants' proposed construction includes the use of a ruthenium
catalyst. The parties did not address in their briefing whether the catalyst in the
claimed process must be ruthenium. At oral argument, Plaintiffs could only point
to one non-ruthenium catalyst in the patents' written description, tr. at 83: 13-84:8,
and the Defendants questioned whether the portion of the written description
Plaintiffs cited actually recites use of a ruthenium catalyst in the oxcarbazepine
reduction process, id at 86:4-7. At this time, I will not construe the term as
requiring the use of a ruthenium catalyst because the written description does not
appear on its face to require that the catalyst that is essential to the invention be a
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ruthenium catalyst. The written description describes use of a catalyst generally,

see, e.g., #135 patent at 1:19-21, 3:2-3, and the plain language of the "chemical
purity" term construed here does not include ruthenium (as described below,
another claim term that recites "ruthenium" is construed to require the use of
ruthenium as a catalyst). If at trial it is established that the catalyst must be
ruthenium, I will revise my construction.
Because the written description shows the claimed invention is a process,
not a compound, I construe "(S)-(-)-10-acetoxy-10, 11-dihydro-SHdibenz/b,f/azepine-5-carboxamide having a chemical purity of at least about

99 .96%" as "eslicarbazepine acetate obtained by a process of reduction of
oxcarbazepine using a catalyst and having a chemical purity of at least about

99.96%."
TERM E

"a compound being (S)-(-)-10-acetoxy-10, 11-dihydro-5Hdibenz/b,f/azepine-5-carboxamide and comprising about 2 ppm of
ruthenium or less" and "less than 2 ppm of ruthenium" in claims
1, 3, and 6 of the #135 patent

1. Plaintiffs' proposed construction: "eslicarbazepine acetate having
an amount of ruthenium at about 2 ppm or less but more than zero"
and "an amount of ruthenium less than 2 ppm but more than zero"
2. Defendants' proposed construction: "eslicarbazepine acetate
obtained by a process of reduction of oxcarbazepine using a
ruthenium catalyst and having an amount of residual ruthenium at
about 2 ppm or less but more than zero" and "an amount of
residual ruthenium less than 2 ppm but more than zero"
3. Court's Construction: "eslicarbazepine acetate obtained by a
process of reduction of oxcarbazepine using a ruthenium
catalyst and having an amount of residual ruthenium at about
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2 ppm or less but more than zero" and "an amount of residual
ruthenium less than 2 ppm but more than zero"

I construe "a compound being (S)-(-)-10-acetoxy-10, l l-dihydro-5Hdibenz/b,f/azepine-5-carboxamide and comprising about 2 ppm of ruthenium or
less" as "eslicarbazepine acetate obtained by a process of reduction of
oxcarbazepine using a ruthenium catalyst and having an amount of residual
ruthenium at about 2 ppm or less but more than zero." And I construe "less than 2
ppm of ruthenium" as "an amount of residual ruthenium less than 2 ppm but more
than zero."
The written description of the #135 patent makes clear that the claimed
ruthenium in eslicarbazepine acetate is the residual ruthenium resulting from a
process of reducing oxcarbazepine in the presence of a ruthenium catalyst. As
described above, the written description shows that the claimed invention of the
# 13 5 patent is a- process for preparing eslicarbazepine acetate by reduction of
oxcarbazepine in the presence of a catalyst and a hydride source. Moreover,
throughout the written description, ruthenium is referred to exclusively as residual.
For example, Example 3 explains that the described process results in "[r]esidual
ruthenium content ... [of] less than 2 ppm. #135 patent at 16:15-17; see also #135
patent at 2:21-25, 6:3, 9:18, 12:36, 16:15. The written description never describes
the ruthenium in the claimed compound as anything other than the residual
ruthenium. Also, as described above, a part of the patent's solution to the prior art
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problem is an improved method that results in low residual ruthenium. Thus, the
use of a ruthenium catalyst that results in a low residual ruthenium content is
essential to obtain the claimed ruthenium content of eslicarbazepine acetate.
The written description shows that the claimed ruthenium is the residual
ruthenium resulting from the claimed process, not the ruthenium in the compound
from any source. Thus, I construe "less than 2 ppm of ruthenium" as "an amount of
residual ruthenium less than 2 ppm but more than zero."

TERM F

"the (R)-isomer of (S)-(-)-10-acetoxy-10, 11-dihydro-5Hdibenz/b,f/azepine-5-carboxamide being below the limit of
detection" and "the amount of (R)-isomer of (S)-(-)-10-acetoxy10, 11-dihydro-5H-dibenz/b,f/azepine-5-carboxamide is below the
limit of detection" and "below the limit of detection" in claims 5,
8, and 11 of the #135 patent and claim 3 of the #929 patent
1. Plaintiffs' proposed construction: "(R)-licarbazepine acetate is not
detectable by HPLC"
2. Defendants' proposed construction: "Indefinite"
3. Court's Construction: "(R)-Iicarbazepine acetate is not
detectable by HPLC"

Because Defendants have not offered a construction of "below the limit of
detection," I adopt Plaintiffs' proposed construction. I will entertain Defendants'
indefiniteness arguments at a later date.

TERM G

"A method of treating partial-onset seizures in a patient who is
suffering from or susceptible to absence seizures, which method
comprises:" in claims 1 and 16 of the #747 patent

The parties agree that this preamble is limiting and that it does not require
construction. I will entertain Defendants' arguments that the term is indefinite at a
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later date.
TERM H

"absence seizures" in claims 1, 9, 16, and 18 of the #747 patent

1. Plaintiffs' proposed construction: "brief, generalized epileptic
seizures with two characteristic features: ( 1) impairment of
consciousness (absence) and (2) particular spike-and-slow wave
discharges as measured by electroencephalography (EEG)"
2. Defendants' proposed construction: "a variety of generalized
seizure which, in contrast to partial-onset seizures, affect the whole
of the brain, producing abnormal electrical activity throughout
both hemispheres and, typically, loss of consciousness. Absence
seizures are brief, generalized epileptic seizures with two
characteristic features: ( 1) impairment of consciousness (absence)
and (2) particular spike-and-slow wave discharges as measured by
electroencephalography (EEG)"
3. Court's Construction: "A variety of generalized seizure which,
in contrast to partial-onset seizures, affect the whole of the
brain, producing abnormal electrical activity throughout both
hemispheres and, typically, loss of consciousness. Absence
seizures are brief, generalized epileptic seizures with two
characteristic features: (1) impairment of consciousness
(absence) and (2) particular spike-and-slow wave discharges as
measured by electroencephalography (EEG)"
At oral argument, Plaintiffs agreed to the use of Defendants' construction of
this term. Tr. 89:12-17. Thus, I will adopt Defendants' proposed construction.
TERM I

"a patient who is suffering from or susceptible to absence
seizures" in claims 1, 16, and 18 of the #747 patent
1. Plaintiffs' proposed construction: "a patient who is suffering from
absence seizures, or who has particular spike-and-slow wave
discharges characteristic of absence seizures and may have been
diagnosed as suffering from absence seizures, may have previously
experienced at least one seizure such as an absence seizure,
myoclonic seizure or tonic-clonic seizure, or may have a family
history of epilepsy"
2. Defendants' proposed construction: "Indefinite"
22

3. Court's Construction: "a patient who is suffering from absence
seizures, or who has particular spike-and-slow wave discharges
characteristic of absence seizures and may have been
diagnosed as suffering from absence seizures, may have
previously experienced at least one seizure such as an absence
seizure, myoclonic seizure or tonic-clonic seizure, or may have
a family history of epilepsy"
Because Defendants have failed to offer a construction of the term "a patient
who is suffering from or susceptible to absence seizures," I will adopt Plaintiffs'
proposed construction. I will entertain Defendants' indefiniteness arguments at a
later date.

TERM J

Construction of claims 3 and 4 of the #646 patent
1. Plaintiffs' proposed construction:
a. Claim 3: "a process for producing a compound having the
general formula I of claim 1 comprising reacting compounds
of formula II
D

with compounds of the general formula III A-CO-R III
wherein: R is the same as defined above for general formula
I; A is hydrogen, halo or ~ 0 - R group or - 0 CO-OR' group, wherein R' is lower alkyl"
b. Claim 4: "the process covered by claim 3 wherein the
reaction is conducted in the presence of at least one
condensing agent or base"
2. Defendants' proposed construction: "Indefinite"
3. Court's Construction:
a. Claim 3: "a process for producing a compound having
the general formula I of clai~ 1 comprising reacting
compounds of formula II
23

n

with compounds of the general formula III A-CO-R
III wherein: R is the same as defined above for general
formula I; A is hydrogen, halo or -0-CO-R group or
-0-CO-OR' group, wherein R' is lower alkyl"
b. Claim 4: "the process covered by claim 3 wherein the
reaction is conducted in the presence of at least one
condensing agent or base.
Because Defendants have not offered a proposed construction of claims 3
and 4 of the #646 patent, I adopt Plaintiffs' proposed construction.
WHEREFORE, at Wilmington this 17th day of October 2019, the Court
adopts the claim constructions set forth above.

(]? $l1-1i(
COLMF ~~OLLY,
UNITED STATES DISTRICT JUDGE

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