Integra LifeSciences Corp. et al v. HyperBranch Medical Technology, Inc

Filing 316

REPORT AND RECOMMENDATIONS regarding claim construction. Please note that when filing Objections pursuant to Federal Rule of Civil Procedure 72(b)(2), briefing consists solely of the Objections (no longer than ten (10) pages) and the Response to the Objections (no longer than ten (10) pages). No further briefing shall be permitted with respect to objections without leave of the Court. Objections to R&R due by 9/5/2017. Signed by Judge Christopher J. Burke on 8/18/2017. (mlc)

IN THE UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF DELAWARE
INTEGRA LIFESCIENCES CORP.,
INTEGRA LIFESCIENCES SALES LLC,
CONFLUENT SURGICAL, INC., and
INCEPT LLC,
Plaintiffs,

v.
HYPERBRANCH MEDICAL
TECHNOLOGY, INC.,
Defendant.

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Civil Action No. 15-819-LPS-CJB

REPORT AND RECOMMENDATION
In this action filed by Plaintiffs Integra LifeSciences Corp. ("Integra"), Integra
LifeSciences Sales LLC ("Integra Sales"), Confluent Surgical, Inc. ("Confluent") and Incept LLC
("Incept") (collectively, "Plaintiffs") against Defendant HyperBranch Medical Technology, Inc.
("HyperBranch" or "Defendant"), Plaintiffs allege infringement of United States Patent Nos.
6,566,406 (the '"406 patent"), 7,009,034 (the '"034 patent"), 7,332,566 (the "'566 patent"),
7,592,418 (the "'418 patent"), 8,003,705 (the "'3705 patent") and 8,535,705 (the "'5705 patent")
(collectively, the "patents-in-suit" or "asserted patents"). Presently before the Court is the matter
of claim construction. The Court recommends that the District Court adopt the constructions set
forth below for the three terms discussed in this Report and Recommendation. 1

The parties submitted 18 terms or sets of terms for claim construction. (D.I. 248
at 2) The parties grouped the 18 terms/term sets into seven groups for purposes of the
Markman hearing. (Id. at 1-2) This Report and Recommendation addresses the third group of
terms (i.e., Group C). On July 27, 2017 and August 4, 2017, the Court issued Reports and
Recommendations regarding claim construction for the first two groups of terms (which included
10 tem1s/term sets), (D .I. 3 07, 310), and the Court will address the remaining groups in separate,
forthcoming Report and Recommendations.

I.

BACKGROUND
The Court incorporates by reference herein the factual and procedural background about

this case and the patents-in-suit that was set out in the Court's July 27, 2017 Report and
Recommendation regarding claim construction. (D.I. 307 at 2-5)

II.

STANDARD OF REVIEW
The Court also incorporates by reference herein the discussion of general principles of

claim construction, as well as the legal standard relating to the definiteness requirement, which
were also set out in its July 27, 2017 Report and Recommendation. (Id. at 5-7, 30-32)

III.

DISCUSSION
The Court takes up the three disputed terms addressed herein in the order in which the

parties addressed them at the Markman hearing.

A.

"chemical groups that are prone to aqueous hydrolysis"

The term "chemical groups that are prone to aqueous hydrolysis" is found in the
independent claims of the '566 patent and the '418 patent. Plaintiffs propose that the term be
construed to mean"[c]hemical groups susceptible to reaction with water to break chemical bonds
and to degrade[.]" (D.I. 230 at 24) Defendant proposes that it be construed to mean "'[c]hemical
linkages that are susceptible to degradation through reaction with water to break chemical bonds,
such as an ester, carbonate, or amide linkage[.]"' (D.I. 231 at 8) The term's usage in claim 1 of
the '566 patent is representative:
1. A polymeric coating for a substrate comprising:
water, a biocompatible visualization agent, and a biodegradable
hydrogel, that is essentially completely degradable in vivo by
hydrolytic degradation, with the hydrogel having an interior and an
exterior, with the exterior having a substrate coating surface, and
2

the visualization agent being at least partially disposed within the
interior,
wherein the hydrogel comprises chemical groups that are prone to
aqueous hydrolysis and is thereby degradable in vitro by exposure
to aqueous solution, and
wherein the visualization agent has a predetermined concentration
that indicates a predetermined thickness of the hydro gel as
deposited on the substrate.
('566 patent, col. 39:2-15 (emphasis added))
The most significant dispute between the parties is whether it is proper for the
construction ofthis term to include the language "such as an ester, carbonate, or amide linkage."

(See D.I. 230 at 25; D.I. 241 at 13) For its part, Defendant asserts that the patents expressly
identify these as exemplary linkages that are susceptible to degradation by reaction with water to
break their chemical bonds. (D.I. 231 at

8~9)

For support, it points to a portion of the '566 patent

specification, which describes an embodiment of the invention as a hydrogel that has "water, a
biocompatible visualization agent, and crosslinked hydrophilic polymers that form a hydrogel
after contact with the [patient's] tissue .... The polymers preferably also have a hydrolytically

biodegradable portion or linkage, for example an ester, carbonate, or an amide linkage." ('566
patent, col. 6:22-25, 44-47 (emphasis added)) 2 Defendant contends that inclusion of these
examples in the construction ensures that Plaintiffs will not "exclude them from the scope of the
claims[.]" (D.I. 231 at 9)
Plaintiffs raise a few different concerns with Defendant's proposal. The Court will
address them in tum.

2

Plaintiffs suggest that this reference is "found in ... later continuation in part
applications." (D.I. 230 at 25; see also D.I. 252 ("Tr.") at 135) To the extent they suggest that
this reference is not found in the '566 patent (or the '418 patent), they are mistaken. (See Tr. at
153; see also '418 patent, col. 6:42-44)
3

First, Plaintiffs assert that Defendant's construction improperly seeks to "limit this term
to 3 specific chemical species: (1) esters; (2) carbonates and (3) amides." (D.I. 230 at 25) And
Plaintiffs then point to the specification as describing "a number of chemical species that can be
used without limitation to only the three named by Defendant[.]" (Id) The portion of the
specification that Plaintiffs cite here is entitled "Biodegradable Linkages[,]" and it teaches that:
If it is desired that the biocompatible crosslinked polymer be
biodegradable or absorbable, one or more precursors having
biodegradable linkages present in between the functional groups
may be used. The biodegradable linkage optionally also may serve
as the water soluble core of one or more of the precursors. In the
alternative, or in addition, the functional groups of the precursors
may be chosen such that the product of the reaction between them
results in a biodegradable linkage. For each approach,
biodegradable linkages may be chosen such that the resulting
biodegradable biocompatible crosslinked polymer will degrade or
be absorbed in a desired period oftime. Preferably, biodegradable
linkages are selected that degrade under physiological conditions
into non-toxic products.

The biodegradable linkage may be chemically or enzyxnatically
hydrolyzable or absorbable. Illustrative chemically hydrolyzable
biodegradable linkages include polymers, copolymers and
oligomers of glycolide, dl-lactide, 1-lactide, caprolactone,
dioxanone, and tritnethylene carbonate. Illustrative enzymatically
hydrolyzable biodegradable linkages include peptidic linkages
cleavable by metalloproteinases and collagenases. Additional
illustrative biodegradable linkages include polymers and
copolymers of poly(hydroxy acid)s, poly(orthocarbonate)s,
poly(anhydride)s, poly(lactone)s, poly(amino acid)s,
poly(carbonate)s, and poly(phosponate)s.
('566 patent, col. 10:19-44 (cited in D.I. 230 at 25)) In light of this teaching, Plaintiffs assert,
Defendant's proposal would improperly exclude these exemplary embodiments of the limitation.
(D.I. 241 at 13; see also D.I. 230 at 26 ("[Because] there is no expression of manifest
exclusion[,] there is no basis to limit this claim limitation to certain embodiments advanced by
4

the Defendant[.]"))
Defendant's proposal would do no such thing. The proposal recites "chemical linkages ..
. such as an ester, carbonate, or amide linkage." The plain import of that construction, then, is
not to limit the term to only encompassing an ester, carbonate or amide linkage, but instead to
provide these three chemical species as exemplary chemical groups that would fall within the
scope of the claim term. (D.I. 243 at 7; D.I. 244 at~ 11; Tr. at 155) The other examples listed in
the patent would not be excluded by this language.
Plaintiffs next argue that it is especially improper to import these embodiments into the
construction because they relate to a different concept-i.e., "hydrolytically degradable"-rather
than to "chemical groups that are prone to aqueous hydrolysis" (the claim term at issue). (D.I.
241 at 13) But it is clear from the claims that the claim language at issue here has a direct
relation to the concept of "hydrolytic degradation." Claim 1 of the '566 patent, set out above,
recites a hydrogel "that is essentially completely degradable in vivo by hydrolytic degradation ..
. wherein the hydrogel comprises chemical groups that are prone to aqueous hydrolysis and is
thereby degradable in vitro by exposure to aqueous solution[.]" ('566 patent, col. 39:4-12
(emphasis added)) And thus, polymers with a "hydrolytically biodegradable portion or linkage"
such as an ester, carbonate or an amide linkage, would be "susceptible to [aqueous]
hydrolysis[,]" which Defendant's expert states means the same thing as "hydrolytic degradation."
(D.I. 232 at~ 83)3
3

Indeed, as Defendant's counsel pointed out during the Markman hearing,
Plaintiffs' own expert Dr. Mays explained in an earlier declaration (issued in conjunction with
the preliminary injunction proceedings) that "[t]he hydrogel may be hydrolytically biodegradable
which means that the hydrogel biodegrades by reacting with water. One such way this can
happen is that the hydrogel includes 'a hydrolytically biodegradable portion or linkage, for
5

During the Markman hearing, Plaintiffs' counsel additionally asserted that Defendant's
construction is improper because it utilizes the term"'linkages" instead of "groups." (Tr. at 138)
That is, the claim language recites "chemical groups that are prone to aqueous hydrolysis"
whereas Defendant's construction (and the portion of the specification that the construction relies
upon) refers to "linkage[s]." According to Plaintiffs, the linkage that is formed is "part of a
group"-"the group encompasses more than just the linkage." (Id. at 139-40) Defendant
retorted that "the patent uses these terms [']linkages['] and [']groups['] synonymously." (Id. at
156) Dr. Lowman likewise appears to view them as synonymous in this context, opining that
"the Asserted Patents define ester, carbonate and amide linkages as exemplary groups that are
susceptible to hydrolysis." (D.I. 232

at~

84 (emphasis added))

The Court is not persuaded by this particular criticism, as it is undercut by the patent and
by Plaintiffs' own arguments. For example, in their briefing, Plaintiffs themselves pointed to the
section of the patent entitled "biodegradable linkages" as describing "a number of chemical
species that can be used" with respect to this claim term. (D.I. 230 at 25) As was noted above,
this discussion of the specification teaches a few ways to achieve a biocompatible crosslinked
polymer that will "degrade or be absorbed in a desired period of time[,]" including that: (1) one
or more precursors having biodegradable linkages present in between the functional groups may
be used, or (2) functional groups of the precursors may be chosen such that the product of the
reaction between them results in a biodegradable linkage. ('566 patent, col. 10:19-30) This
discussion next proceeds to list "[i]llustrative ... biodegradable linkages[,]" (id., col. 10:33-44),

example an ester ... linkage.'" (Defendant's Claim Construction Presentation, Slide 102 (citing
D.I. 10, ex. 13 at~ 84); see also Tr. at 154)
6

which Plaintiffs describe as being "exemplary embodiments" of this limitation, (D.I. 241 at 13;
see also D.I. 242, ex. 14 at if 65 (Dr. Mays opining that Defendant's proposal excludes
embodiments recited in the "biodegradable linkages" discussion of the specification and
improperly limits the term to "three chemical species" when the patents describe "several other
chemical species that can be used" such as the aforementioned biodegradable linkage examples))
Moreover, in another portion of their briefing, Plaintiffs again seemed to treat chemical "groups"
and "linkages" as synonyms in this context. (See, e,g., D.I. 230 at 11 (asserting that claim 17 of
the '5705 patent "'does not exclude the presence of other biodegradable groups, but at
physiological conditions in vivo, the claim requires that the biodegradable groups responsible
for degradation in less than about 90 days only be ester groups. Accordingly, the hydrogel of
claim 17 can include amide linkages, but the biodegradable linkages can only be ester groups"')
(citing D.I. 10, ex. 13 at if 167) (certain emphasis omitted)) And so, with the patent (and the
Plaintiffs) appearing to use the two terms interchangeably in this context, the Court is not
persuaded that Defendant has improperly inserted "linkages" in place of "groups" in its proposed
construction.
One final argument from Plaintiffs also became clear during the Markman hearing: that
Plaintiffs "disagree that the amide linkage [included in Defendant's proposal] falls within [a
chemical] group [that] is prone to aqueous hydrolysis." (Tr. at 136-J7) This particular argument
was not made clear in Plaintiffs' briefing, where Plaintiffs mostly (incorrectly) argued that
Defendant's construction is wrong because it excludes other examples. The only support that
Plaintiffs provided for this late-made argument at the Markman hearing was that "there's a real
fight over whether [an amide linkage is] biodegradable in other physiological conditions." (Id at

7

141) This bare assertion is not enough to persuade the Court that the phrase should not be
included in the construction, especially where: (1) the patent defines an "amide linkage" as an
exemplary group that is susceptible to hydrolysis, (D.I. 232 at~ 84); and (2) Defendant suspects
that Plaintiffs may attempt to later exclude amide linkages from the scope of the claim, (Tr. at
152).
For these reasons, the Court recommends that "chemical groups that are prone to aqueous
hydrolysis" be construed to mean "chemical linkages that are susceptible to degradation through
reaction with water to break chemical bonds, such as an ester, carbonate, or amide linkage."

B.

"the biodegradable groups of the hydrogel consist of the esters"

Plaintiffs propose that this next term be construed to mean "'the esters are the only
biodegradable group responsible for degradation in a patient in less than about 180 days[,]"'
while Defendant proposes that it be construed to mean "'the hydrogel does not contain any
biodegradable linkages other than ester linkages[.]"' (D.I. 231 at 9) The term is found in claim 1
of the '5705 patent, as shown below:

1. A method of making a biocompatible degradable hydro gel to
treat a medical condition of a patient comprising:
identifying a medical condition for treatment by use of a hydrogel
formed in situ in a patient and fully degradable in a patient in less
than about 180 days; and
mixing a first precursor with a second precursor in situ in the
patient to form the hydro gel for treatment of the medical
condition;
with the first biocompatible synthetic hydrophilic polymer
precursor having a water solubility of at least 1 gram per 100
milliliters and comprising at least two electrophilic functional
groups; and the second biocompatible synthetic hydrophilic
polymer precursor comprising at least two nucleophilic amine
functional groups; and
wherein
8

(i) the first precursor is selected to have only one or two
chemically hydrolytically degradable ester bonds per every
electrophilic functional group on the first precursor; and
(ii) the second precursor comprises at least three nucleophilic
functional groups;
wherein the biodegradable groups of the hydrogel consist of the
esters and the hydrogel as placed in situ in the patient is essentially
fully degradable in a patient in less than about 180 days, and
wherein mixing the first and the second synthetic hydrophilic
polymer precursors forms crosslinking covalent bonds that are
reaction products of the electrophilic and the nucleophilic groups,
wherein essentially every ester bond in the hydrogel is separated
from other ester bonds in the hydrogel by at least three covalent
bonds when the hydrogel is formed.
('5705 patent, col. 30:34-65 (emphasis added)) Claim 17 depends from claim 1 and requires that
"the hydrogel is essentially fully degradable in a patient in less than about 90 days'." (Id., col.
32: 16-17) The crux of the dispute with respect to this term is whether its effect is that (1) the
claimed hydrogel must not contain any biodegradable linkages other than ester linkages (as
Defendant argues), or (2) whether the hydro gel can include other biodegradable linkages, but that
those linkages that are biodegradable linkages under the conditions specified in the claims (i.e.,
in a patient in less than about 180 (or 90) days) must be ester groups (as Plaintiffs contend).
(See D.I. 230 at 11-12)
The Court looks first to the claim language itself, which supports Defendant's position.
As an initial matter, the claim language does not say something like: the "biodegradable groups
of the hydrogel responsible for degradation consist of the esters." Instead, it reads: "the
biodegradable groups of the hydrogel consist of the esters."4

4

Plaintiffs assert that antecedent basis for the term "the biodegradable groups of the
hydrogel consist of the esters" is found only in the term "'one or two chemically hydrolytically
degradable ester bonds per every electrophilic functional group on the first precursor."' (D .I. 241
at 14; D.I. 159 at 69-70) According to Plaintiffs, the person of ordinary skill in the art (or
9

Beyond this, the Court agrees with Defendant that the effect of the "consist of' language
in the phrase is to strictly limit the biodegradable groups of the claimed hydro gel to only ester
groups. (D.I. 231 at 9; Tr. at 156-57) The United States Court of Appeals for the Federal. Circuit
has explained that "'consisting of" is a term of art in patent law "[that] signifies restriction and
exclusion ofunrecited steps or components." Conoco, Inc. v. Energy & Envtl. Int'!, L.C., 460
F.3d 1349, 1360 (Fed. Cir. 2006); see also Vehicular Techs. Corp. v. Titan Wheel Int'!, Inc., 212
F.3d 1377, 1383 (Fed. Cir. 2000) ("[A] drafter uses the phrase 'consisting of to mean 'I claim
what follows and nothing else."') (citation omitted).
Plaintiffs assert that the law with respect to "consisting of' does not support Defendant's
"overly exclusionary" position, because the Federal Circuit has held that "consisting of' "does
not exclude elements outside of the context of said element." (D.I. 230 at 14) The two cases that
Plaintiffs cite in support of this proposition-Norian Corp. v. Stryker Corp., 363 F.3d 1321 (Fed.
Cir. 2004) and Conoco, Inc. v. Energy & Envtl. Int'!, L.C., 460 F.3d 1349 (Fed. Cir. 2006)-set
out two narrow exceptions to the above-referenced rule. First, the Federal Circuit has explained

"POSITA") would thus understand this portion of the claim to mean that the "'one or two
chemically hydrolytically degradable ester bonds"' or groups "'consist of the esters"'-in other
words, this language is said to make clear that the ester groups are what is responsible for the
degradation of the hydrogel within 180 days. (D.I. 241at14; D.I. 159 at 69-70) This
explanation, however, essentially renders the term at issue redundant. That is, it would reaffirm
what has already been said in the claim-that the ester bonds are hydrolytically degradable.
Accepting Defendant's position instead gives this term actual meaning-Defendant asserts that
the "one or two chemically hydrolytically degradable ester bonds" language sets out a structural
requirement for the precursor, while the term at issue sets out a structural requirement for the
hydrogel. (D.I. 159 at 199) This is consistent with the claim's later reference to ester bonds as
structures in the hydrogel-the claim recites "mixing the first and the second synthetic
hydrophilic polymer precursors forms crosslinking covalent bonds that are reaction products of
the electrophilic and nucleophilic groups, wherein essentially every ester' bond in the hydrogel is
separated from other ester bonds in the hydrogel by at least three covalent bonds when the
hydrogel is formed." ('5705 patent, col. 30:59-65; see also D.I. 231at10)
10

that "consisting of' "does not limit aspects unrelated to the invention." Norian Corp., 363 F.3d
at 1331-32 (emphasis added) (concluding that claims directed to a kit "consisting of' specified
chemicals did not permit any other chemicals in the kit, but finding that the presence of a spatula
in the accused kit containing the same claimed chemicals did not help the defendant avoid
infringement, for the spatula "has no interaction with the chemicals, and is irrelevant to the
invention"). The Federal Circuit has recently emphasized that this is a "rare exception" that is
not often implicated. Shire Dev., LLC v. Watson Pharms., Inc., 848 F.3d 981, 984 (Fed. Cir.
2017). Second, the Federal Circuit has also noted that "impurities that a person of ordinary skill
in the relevant art would ordinarily associate with a component on the 'consisting of list do not
exclude the accused product or process from infringement." Conoco, Inc., 460 F.3d at 1360.
Neither of these exceptions apply here. Under Plaintiffs' view, the claims permit other
biodegradable groups, aside from esters, to exist in the hydrogel. But the Court cannot
understand how inclusion of other biodegradable groups in the hydrogel would not be an aspect
related to this invention (nor have Plaintiffs made any attempt to shed light on that issue). And
no one is asserting that other such groups would be akin to the "impurities" at issue in Conoco,
Inc. Thus, the plain import of the term "the biodegradable groups of the hydrogel consist of the

esters" is that the claimed hydrogel does not contain any biodegradable groups other than the
esters (and that if it does, it does not meet the limitations of the claims).
The Court also agrees with Defendant that the prosecution history supports its proposal.
The Court will now set out the relevant portion of this prosecution history in some detail. To
provide context for this discussion, the Court notes that Dr. Lowman has opined that a
'"biodegradable group' is a chemical structure that is susceptible to degradation, either hydrolytic
11

or enzymatic." (D.I. 232

at~

86 (emphasis added); see also Tr. at 157)

Originally, the forerunner to the claim that ultimately issued as claim 1 of the '5705 patent
did not include a limitation regarding the types of biodegradable groups present in the claimed
hydrogel. (D.I. 232, ex. 7 at HBMT0405076-82) To overcome rejections, the patentees next
added the limitation "wherein the hydrogel as placed in situ in the patient has no enzymatically
degradable peptidic linkages and is essentially fully degradable in a patient in less than about

180 days[.]" (Id. at HBMT0405456 (certain emphasis added, certain emphasis omitted), see also
id. at HBMT0405461 ("The amended claims are amended to recite that the hydrogel as placed in

situ in the patient has no enzymatically degradable peptide linkages.")) This limitation narrowed
the pending claim by excluding hydrogels with enzymatically degradable peptide linkages (and
thus covered hydrogels with hydrolytically degradable linkages). (See id. at HBMT0405501
("The claim language that the hydrogel as placed in situ in the patient has no enzymatically
degradable peptidic linkages is directed to claiming one of these alternatives, namely chemically
degradable via a hydrolytically degradable ester and not the other alternative, namely
enzymatically biodegradable linkages."); D.I. 232 at~ 88) The Examiner continued to reject the
claims, however, and the patentee ultimately abandoned the application. (D.I. 232, ex. 7 at
HBMT0405547-50, HBMT0405570~ 72, HBMT0405577)
The applicants then re-filed a new continuation application that became the '5705 patent,
in which they resubmitted the claims reciting the "no enzymatically degradable peptidic
linkages" limitation. (Id., ex. 6 at HBMT0408834) The Examiner rejected the claims as
unpatentable in view of U.S. Patent No. 5,874,500, a prior art reference referred to as "Rhee
'500." (Id. at HBMT0409300) According to the Examiner, Rhee '500 teaches a method of
12

making a hydrogel that, inter alia, as placed in situ "has no enzymatically degradable peptidic
linkages[,]" and "[i]t would have been obvious to [the POSITA] at the time the instant invention
was made to prepare a hydrogel according to the method of [Rhee '500] containing hydrolytically
degradable linkages." (Id. at HBMT0409300-01)
Because excluding hydrogels with enzymatically degradable peptidic linkages did not
suffice to gain allowance of the claims, the patentees then deleted the "has no enzymatically
degradable peptidic linkages" limitation and replaced it with the current phraseology-i.e.,
"wherein the biodegradable groups of the hydrogel consist of the esters[.]" (Id. at
HBMT0409335) With respect to this amendment, the applicants explained that "[c]laim 1 is
amended to clarify that the biodegradable groups are the isolated esters[.]" (Id. at
HBMT0409338 (emphasis added))
As for the rejection over Rhee '500, the applicants argued that Rhee '500 taught the
artisan to add certain enzymatically degradable peptides or certain biodegradable materials such
as lactide, glycolide, E-caprolactone, poly( a-hydroxy acid), poly(amino acids) or poly(anhydride)
to make a composition that was easily degraded. (Id. at HBMT0409344) None of these
materials were ester groups. (Id.) The applicants then explained that "the present claims do not
read on any of these materials. For instance, adding a polyanhydride places the precursor

outside of the claims." (Id. (emphasis added); see also id. at HBMT0409377) Dr. Lowman
points out that the '5705 patent lists some of these same biodegradable materials as examples of
biodegradable linkages, (D.I. 232 at if 92):
The biodegradable linkage may be chemically or enzymatically
hydrolyzable or absorbable. Illustrative chemically hydrolyzable
biodegradable linkages include polymers, copolymers and
13

oligomers of glycolide, dl-lactide, l-lactide, caprolactone,
dioxanone, and trimethylene carbonate .... Additional illustrative
biodegradable linkages include polymers and copolymers of
poly(hydroxy acid)s, poly(orthocarbonate)s, poly(anhydride)s,
poly(lactone)s, poly(aminoacid)s, poly(carbonate)s, and
poly(phosphonate)s.
('5705 patent, cols. 6:61-7:5 (emphasis added))
The clear import of the prosecution history, then, is that the claim covers only those
hydrogels that do not contain biodegradable groups other than esters. (See D.I. 232 at iii! 88, 91)
Indeed, the applicants explicitly said that they added the language at issue to clarify that the
biodegradable groups are the esters, and they also explained how adding a degradable material to
the precursor that was not an ester (i.e., a polyanhydride) would remove it from the scope of the
claimed invention.
Plaintiffs' responses to Defendant's arguments relating to the prosecution history are not
persuasive. Plaintiffs first attempt to dispute the relevance of Defendant's citations by asserting
that the claim term at issue "is neither mentioned nor discussed in the portions of the prosecution
history cited by" Defendant. (D.I. 241 at 15) This is true at least for the first portion of the
prosecution history discussed above, because the phrase at issue was not even a limitation in the
claim at that point. Rather, that discussion is relevant here because it shows how this term
originated; the applicants replaced the earlier "no enzymatically degradable peptidic linkages"

language with the phrase at issue.
Plaintiffs also argue that "[w]hat the prosecution history actually shows is that applicants
did not limit claims to hydrogels only having ester linkages, but rather distinguished the claims
from SG-PEG hydrogels having esters that were persistent, not biodegradable in a patient, unless

14

specifically modified with other biodegradable groups[.]" (Plaintiffs' Claim Construction
Presentation, Slide 53; see also D.I. 241 at 15; Tr. at 147-48) And it is correct that the applicants
did further explain that Rhee '500 "does not teach that the esters in the SG-PEG are
biodegradable and, to the contrary, repeatedly and explicitly states that the materials of the
[Rhee] '500 patent are persistent unless specifically modified with other biodegradable
groups"-all to provide one reason why the prior art reference taught away from what is claimed.
(D.I. 232, ex. 6 at HBMT0409344 (emphasis in original)) But this was not the only reason the
applicants gave as to why Rhee '500 should not stand in the way of their claims. Right before
giving that reason, the applicants had made the previously-referenced statement that "the present
claims do not read on any of these [other biodegradable] materials [that are not esters]" and
asserted that adding one such (non-ester) material to the precursor would place it outside of the

claims. (Id (emphasis added)) Plaintiffs never directly address these statements in the
prosecution history. Their failure to do so is a tacit admission of the impact of those statements.
The Court agrees with Defendant that these prosecution history statements are
"unequivocal"-i.e., that other biodegradable materials are "out" for the purposes of this claim
and the patentees "limited it strictly down to the esters." (Tr. at 158-59; see also D.I. 231at12) 5
For these reasons, the Court recommends that the term "the biodegradable groups of the hydrogel
consist of the esters" be construed to mean "the hydro gel does not contain any biodegradable

5

As Defendant points out, Plaintiffs' contrary position "would permit [them] to
assert that a hydro gel with a polyanhydride group fell within the scope of the claims[,]" when
they clearly told the United States Patent and Trademark Office that inclusion of such a material
in a precursor making up the hydrogel would not fall within the claims. (D.I. 231 at 13)
15

linkages other than ester linkages."6

C.

"essentially completely degradable"

The term "essentially completely degradable" appears in claims 1 and 25 of the '566
patent and claim 1 of the '418 patent in the following context: "a biodegradable hydro gel[] that is
essentially completely degradable in vivo by hydrolytic degradation[.]" ('566 patent, cols. 39:2-

15, 40:41-58; '418 patent, cols. 38:66-39:9 (emphasis added)) Plaintiffs propose that the term be
construed to mean "[d]egradation is nearly, though not entirely complete[.]" (D.I. 230 at 15)
Defendant asserts that the term is indefinite as the language "essentially completely" is a
subjective phrase, and no guidance can be found in the intrinsic record with regard to the term's
boundaries. (D.I. 231 at 26)
Defendant first notes that, in the context of the claims, the term "essentially completely
degradable" relates to the degree of degradation achieved by means of hydrolytic degradation.

(Id.) Defendant then asserts that the intrinsic record sheds no light on what degree of degradation
would satisfy the "essentially completely" limitation. (Id at 26-27) It argues that Plaintiffs'
proposal improperly connotes measuring degradation at a specific point in time (i.e., before
complete degradation but after the majority of degradation has occurred), but that this is not
supported by the intrinsic record. (Id at 27) Additionally, Defendant contends that Plaintiffs'

6

Plaintiffs assert in their answering brief as to this term that "[t]here is no support
for [Defendant's] improper attempt to swap 'biodegradable groups' with 'biodegradable
linkages[,]"' (D.I. 241 at 14), but as discussed above, it is clear that "groups" and "linkages" are
at times used synonymously with each other. Indeed, Plaintiffs themselves used the terms
synonymously while arguing about this term in their opening brief. (See, e.g., D.I. 230 at 11-12
("[T]he hydrogel of claim 17 can include amide linkages, but the biodegradable linkages can only
be ester groups.") (citing D.I. 234, ex. 13 at iI 167); ("This phrase does not mean that the claimed
hydrogel does not contain any biodegradable linkage other than ester linkages[.]"); see also Tr. at
156)
16

proposal does not give any guidance on when degradation should be measured or how much
degradation is "nearly, though not entirely, complete." (Id) Finally, Defendant argues that the
prosecution history demonstrates that Plaintiffs' proposal is wrong because the inventors
intended degradation to occur "essentially completely" by means of chemical (hydrolytic)
degradation as opposed to enzymatic degradation. (Id)
It is clear that it is the word "essentially" that is causing the problem for Defendant here,
as "[c]ompletely degradable"'would be clear and would not implicate a term of approximation.
(See Tr. at 149-50); see also, e.g., Ruckus Wireless, Inc. v. Netgear, Inc., No. C 08-2310 PJH,
2013 WL 6627737, at *4 (N.D. Cal. Dec. 16, 2013) (identifying "essentially" as a term of
approximation); Shell Global Solutions (US) Inc. v. RMS Eng 'g, Inc., 782 F. Supp. 2d 317, 343
(S.D. Tex. 2011) (same). The Federal Circuit has explained that "words of approximation, such
as 'generally' and 'substantially,' are descriptive terms 'commonly used in patent claims to avoid
a strict numerical boundary to the specified parameter.'" Anchor Wall Sys., Inc. v. Rockwood
Retaining Walls, Inc., 340 F.3d 1298, 1310-11 (Fed. Cir. 2003) (citations omitted).
This issue is a difficult one. The Court is not in a position to resolve every issue raised by
the parties with respect to this term at this time. However, the Court has come to a few
conclusions.
First, the Court is convinced that Plaintiffs' proposal does not move the ball in terms of
what the term "essentially completely degradable" actually means. Their proposal unhelpfully
swaps out "essentially" for "nearly, though not entirely" without providing a persuasive
explanation as to how this proposal eliminates any uncertainties raised by the claim language.
Nor, for purposes of claim construction, does their briefing explain where the patent utilizes the
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term "nearly" to mean "essentially."
Second, the Court agrees with Defendant's assertion that Plaintiffs' proposal is wrongly
directed to the timing of the process of degradation. The language "degradation is nearly, though
not entirely, complete" suggests that the claim is directed to a hydrogel that has already been
applied to the patient, with time having passed. Yet the claims at issue are directed to a hydro gel
having certain features and to methods of making such hydro gels-not necessarily to hydro gels
that have already been applied to a patient, with enough time having passed to allow for an
almost finalized degradation process.
Third, the Court does find that the term at issue can be construed. 7 Although the term
"essentially completely degradable" does not appear in the specifications, the Court gleans from
the patents that a biodegradable hydrogel "that is essentially completely degradable in vivo by
hydrolytic degradation" is one that may almost completely degrade (in vivo by hydrolytic
degradation), with the word "essentially" allowing for a "small" amount of hydro gel to remain.
As Plaintiffs point out, the specification explains that if it is desired that the biocompatible
crosslinked polymer be biodegradable, "biodegradable linkages may be chosen such that the
resulting biodegradable biocompatible crosslinked polymer will degrade ... in a desired period

7

In a footnote in their opening brief, Plaintiffs "noted" that the claim term only
appears in the preamble of claim 1 of the '418 patent and claim 25 of the '566 patent and is
therefore "presumptively [] not a limitation of the claim that requires construction by the Court."
(D.I. 230 at 15) Defendant did not respond to this "note" and Plaintiffs.did not further press the
issue. Generally, a preamble is not limiting unless it recites an "essential structure or steps" or is
"necessary to give life, meaning, and vitality to the claim." Catalina Mkgt. Int 'l, Inc. v.
Coo/savings.com, Inc., 289 F.3d 801, 808 (Fed. Cir. 2002) (internal quotation marks and citation
omitted). A preamble will also be deemed to be limiting where the patent applicants clearly
relied on the benefits or features recited therein as patentably significant. Id. at 808-09. With
virtually no argument from the parties on the issue, the Court will assume, without deciding, that
the phrase is a claim limitation in all three claims in which it appears.
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oftime." ('566 patent, col. 10:19-30 (emphasis added)) Example 21 of the specification, in tum,
describes experiments whereby satisfactory results ("[n]o adhesions") were achieved even with a

"[s]mall amount of gel present on cecum[.]" (Id., col. 37:20-45 (emphasis added)) The
Examples are of course intended to illustrate aspects of the patentee's inventions, (see, e.g., id.,
col. 28:15-18), and the experiments described in Example 21 depict a hydrogel that prevented
adhesions even where it did not completely degrade but instead left a small amount of gel. The
Court's understanding of the term "essentially" in this context also comports with the
specification's other usages of the term "essentially." (See, e.g., id., col. 5:27-32 ("A substrate
coating surface is a surface of a hydrogel that contacts a substrate and, in the region of contact, is

essentially in continuous contact with that substrate. Although some small portions of the
coating or substrate may not be in contact, the contact is intimate.") (emphasis added)) Thus, in
line with the specification, the Court believes that the import of the "essentially completely
degradable" language is to describe a hydrogel of a kind such that it will degrade so that no more
than a small amount remains.
Fourth, while the Court can understand what "essentially" is intended to get at with
respect to the claimed hydrogel, it remains unclear to the Court on this record whether the claim
term is indefinite. The Court has adopted a construction different from that proposed by
Plaintiffs, and could use a better record and more focused argument as to whether the nowconstrued claim term fails to inform, with reasonable certainty, those skilled in the art about the
scope of the invention. 8 Accordingly, the Court's decision here is without prejudice to

8

For example, even after the Supreme Court of the United States' decision in
Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120, 2125 (2014), claim terms utilizing
terms of degree have been found definite where they provide "'enough certainty to one of skill in
19

Defendant's ability to challenge the validity of the claims containing this term as indefinite at the
summary judgment stage if it believes there is a basis to do so. See Spectrum Pharms., Inc. v.

InnoPharma, Inc., Civil Action No. 12-260-RGA-CJB, 2014 WL 3365684, at *9 (D. Del. July 3,
2014) (citing cases).
For these reasons, the Court recommends that the term "essentially completely
degradable" be construed to mean "degradable to the extent that no more than a small amount of
the hydrogel remains."
IV.

CONCLUSION

For the foregoing reasons, the Court recommends that the District Court adopt the
following constructions:
1.

"chemical groups that are prone to aqueous hydrolysis" should be construed to

mean "chemical linkages that are susceptible to degradation through reaction with water to break
chemical bonds, such as an ester, carbonate, or amide linkage"
2.

"the biodegradable groups of the hydrogel consist of the esters" should be

the art when read in the context of the invention."' Sonix Tech. Co., Ltd v. Publ'ns Int'/ Ltd,
844 F.3d 1370, 1377 (Fed. Cir. 2017) (quoting Interval Licensing LLC v. AOL, Inc., 766 F.3d
1364, 1370 (Fed. Cir. 2014)); see, e.g., Edgewell Personal Care Brands, LLC v. Albaad Massuot
Yitzhak, Ltd, Civil Action No. 15-1188-RGA, 2017 WL 1900736, at *2-3 (D. Del. May 9, 2017)
(rejecting the defendant's argument that the term "generally tapered" was indefinite where the
patent "informs with reasonable certainty" the POSITA regarding the meaning of the term); Saint
Lawrence Commc'ns LLCv. ZTE Corp., Case No. 2:15-CV-349-JRG, 2016 WL 6275390, at
*64-67 (E.D. Tex. Oct. 25, 2016) (finding that even though "substantially" is a word of degree
that may be imprecise, the term "substantially decoupled" was not indefinite where the "intrinsic
and extrinsic evidence demonstrate that 'substantially decoupled' is reasonably well-understood
in the relevant art such that the claims at issue inform[ s] those skilled in the art about the scope
of the invention with reasonable certainty") (certain internal quotation marks and citations
omitted). The Court would benefit from further argument as to why this term of degree is or is
not sufficiently objective, as compared to the results in other cases like these.
20

construed to mean "the hydrogel does not contain any biodegradable linkages other than ester
linkages"
3.

"essentially completely degradable" should be construed to mean "degradable to

the extent that no more than a small amount of the hydro gel remains"
This Report and Recommendation is filed pursuant to 28 U.S.C. § 636(b)(l)(B), Fed. R.
Civ. P. 72(b)(l), and D. Del. LR 72.1. The parties may serve and file specific written objections
within fourteen (14) days after being served with a copy of this Report and Recommendation.
Fed. R. Civ. P. 72(b)(2). The failure of a party to object to legal conclusions may result in the
loss of the right to de novo review in the district court. See Henderson v. Carlson, 812 F.2d 874,
878-79 (3d Cir. 1987); Sincavage v. Barnhart, 171 F. App'x 924, 925 n.1 (3d Cir. 2006).
The parties are directed to the Court's Standing Order for Objections Filed Under Fed. R.
Civ. P. 72, dated October 9, 2013, a copy of which is available on the District Court's website,
located at http://www.ded.uscourts.gov.

Dated: August 18, 2017
Christopher J. Burke
UNITED STATES MAGISTRATE JUDGE

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