Case: 19-1527 Document: 59 Page: 1 Filed: 08/27/2020
United States Court of Appeals
for the Federal Circuit
______________________
BAXALTA INC., BAXALTA GMBH,
Plaintiffs-Appellants
v.
GENENTECH, INC.,
Defendant-Appellee
CHUGAI PHARMACEUTICAL CO. LTD.,
Defendant
______________________
2019-1527
______________________
Appeal from the United States District Court for the
District of Delaware in No. 1:17-cv-00509-TBD, Circuit
Judge Timothy B. Dyk.
______________________
Decided: August 27, 2020
______________________
WILLIAM R. PETERSON, Morgan, Lewis & Bockius LLP,
Houston, TX, argued for plaintiffs-appellants. Also repre-
sented by NATALIE A. BENNETT, Washington, DC; MICHAEL
J. ABERNATHY, CHRISTOPHER JOHN BETTI, MARIA DOUKAS,
KARON NICOLE FOWLER, SANJAY K. MURTHY, Chicago, IL;
JULIE S. GOLDEMBERG, Philadelphia, PA.
ERIC ALAN STONE, Paul, Weiss, Rifkind, Wharton &
Garrison LLP, New York, NY, argued for defendant-
Case: 19-1527 Document: 59 Page: 2 Filed: 08/27/2020
2 BAXALTA INC. v. GENENTECH, INC.
appellee. Also represented by ALEXANDER ATKINS,
MARISSA DORAN, JENNIFER GORDON, NICHOLAS P.
GROOMBRIDGE, NAZ WEHRLI, JOSEPHINE YOUNG; DAVID
COLE, KENNETH A. GALLO, Washington, DC.
______________________
Before MOORE, PLAGER, AND WALLACH, Circuit Judges. 1
MOORE, Circuit Judge.
Baxalta Inc. sued Genentech, Inc. and Chugai Pharma-
ceutical Co. Ltd., 2 alleging infringement of claims 1, 4, 17,
and 19 of U.S. Patent No. 7,033,590. On December 3, 2018,
the United States District Court for the District of Dela-
ware issued a claim construction order, construing the
terms “antibody” and “antibody fragment.” Following the
claim construction order, the parties stipulated to non-in-
fringement of the asserted claims. The district court en-
tered judgment based on its claim construction order and
the parties’ stipulation. Baxalta appeals the district court’s
judgment, arguing the district court’s claim constructions
were erroneous. We have jurisdiction under 28 U.S.C.
§ 1295(a)(1).
Because the district court erred in construing the terms
“antibody” and “antibody fragment,” we vacate the district
court’s judgment of non-infringement and remand.
I. BACKGROUND
Baxalta sued Genentech, asserting that Genentech’s
Hemlibra® (emicizumb-kxwh) product used to treat the
1 Judge Stoll recused and took no part in this deci-
sion. Judge Plager replaced Judge Stoll on the panel fol-
lowing oral argument.
2 Chugai was later voluntarily dismissed from the
lawsuit pursuant to a joint stipulation between Chugai and
Baxalta. J.A. 15946–47.
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BAXALTA INC. v. GENENTECH, INC. 3
blood clotting disorder hemophilia infringes claims 1, 4, 17,
and 19 of the ’590 patent. Blood clotting occurs in the body
through a series of enzymatic activations known as the “co-
agulation cascade.” ’590 patent at 1:7–10. One “key step”
in the cascade is when an enzyme known as activated clot-
ting factor VIII (FVIIIa) complexes with another enzyme
known as activated clotting factor IX (FIXa) to form a com-
plex that then activates factor X (FX). ’590 patent at
1:17–19. Hemophilia A is a particular form of hemophilia
where the activity of factor VIII is functionally absent,
thereby impeding the coagulation cascade. This can occur
in some Hemophilia A patients because they develop factor
VIII inhibitors (i.e., antibodies against factor VIII), which
hinder the effectiveness of factor VIII preparations admin-
istered as treatments. ’590 patent at 1:24–32. The ’590
patent relates to preparations used to treat hemophilia pa-
tients who have developed factor VIII inhibitors. ’590 pa-
tent at 2:25–29. The preparations comprise antibodies or
antibody fragments that bind to factor IX or factor IXa to
increase procoagulant activity of factor IXa to compensate
for the decreased factor VIII activity. See, e.g., ’590 patent
at 2:29–34. Independent claim 1 and dependent claims 4
and 19 are illustrative and recite:
1. An isolated antibody or antibody fragment
thereof that binds Factor IX or Factor IXa and in-
creases the procoagulant activity of Factor IXa.
4. The antibody or antibody fragment according to
claim 1, wherein said antibody or antibody frag-
ment is selected from the group consisting of a
monoclonal antibody, a chimeric antibody, a hu-
manized antibody, a single chain antibody, a
bispecific antibody, a diabody, and di-, oligo- or
multimers thereof.
19. The antibody or antibody fragment according to
claim 4, wherein the antibody is a humanized anti-
body.
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4 BAXALTA INC. v. GENENTECH, INC.
The parties disputed the construction of the terms “an-
tibody” and “antibody fragment,” among other terms not at
issue on appeal. Generally, antibodies are Y-shaped struc-
tures comprising two heavy chains (H chains) and two light
chains (L chains). An antibody that has two identical H
chains and two identical L chains is called “monospecific”
because each H-L chain pair binds the same antigen.
Bispecific antibodies, like Genentech’s product Hemlibra®
(emicizumb-kxwh), have different heavy chains and/or dif-
ferent light chains, allowing them to bind two different an-
tigens. Baxalta argued “antibody” should be construed as
“[a] molecule having a specific amino acid sequence com-
prising two heavy chains (H chains) and two light chains
(L chains).” Genentech argued “antibody” should instead
be construed as “[a]n immunoglobulin molecule, having a
specific amino acid sequence that only binds to the antigen
that induced its synthesis or very similar antigens, consist-
ing of two identical heavy chains (H chains) and two iden-
tical light chains (L chains).”
The district court determined that “the term antibody
standing alone without other structural terms can have dif-
ferent meanings to those skilled in the art,” and that both
Baxalta’s and Genentech’s proposed constructions were ac-
ceptable definitions. Baxalta Inc. v. Genentech, Inc.,
No. 17-509,
2018 WL 6304351, at *4 (D. Del. Dec. 3, 2018).
It determined, however, that the patentee “chose [Genen-
tech’s] narrower definition” by expressly defining antibod-
ies in column 5 of the patent, which states:
Antibodies are immunoglobulin molecules having a
specific amino acid sequence which only bind to an-
tigens that induce their synthesis (or its immuno-
gen, respectively) or to antigens (or immunogens)
which are very similar to the former. Each immu-
noglobulin molecule consists of two types of poly-
peptide chains. Each molecule consists of large,
identical heavy chains (H chains) and two light,
also identical chains (L chains).
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BAXALTA INC. v. GENENTECH, INC. 5
Id. at *5 (quoting ’590 patent at 5:56–63).
Although the district court recognized that the ’590 pa-
tent claims and discloses “bispecific antibodies, which do
not have identical heavy and light chains,” and IgM and
IgA antibodies, which “can have more than two heavy
chains and more than two light chains,” it determined that
these claimed embodiments were “antibody derivatives” ra-
ther than “antibodies.”
Id. at *5–6.
The district court like-
wise dismissed the “inconsisten[cy]” between Genentech’s
definition of “antibody” and “at least dependent claims 4
and 19” as insufficient to overcome what it considered to be
the definitional language of column 5.
Id. at *11. The dis-
trict court therefore adopted Genentech’s construction,
construing “antibody” as “an immunoglobulin molecule,
having a specific amino acid sequence that only binds to
the antigen that induced its synthesis or very similar anti-
gens, consisting of two identical heavy chains (H chains)
and two identical light chains (L chains).”
Id. at *12.
To support its construction, the district court cited an
amendment Baxalta made during prosecution of the
’590 patent. Original claim 1 recited “[a]n antibody or an-
tibody derivative against factor IX/factor IXa which in-
creases the procoagulant activity of FIXa.” J.A. 15961.
Original dependent claim 4 recited a list of “antibod[ies] or
antibody derivative[s] according to claim 1” including “chi-
meric antibodies, humanized antibodies, single chain anti-
bodies, bispecific antibodies, diabodies and di-, oligo- or
multimers thereof.”
Id. During prosecution, the patent ex-
aminer rejected the term “antibody derivatives” as not en-
abled for “any antibody derivative against factor IX/factor
IXa which increases the procoagulant activity of FIXa in
claim 1” or any one of the enumerated list in dependent
claim 4. J.A. 15987, 16008. Based on the examiner’s sug-
gestion, the patentee amended the claims to recite “anti-
body fragment” in place of “antibody derivative” and the
examiner removed the enablement rejection. The district
court determined that this amendment amounted to a
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6 BAXALTA INC. v. GENENTECH, INC.
disclaimer of antibody derivatives “including bispecific an-
tibodies, except antibody fragments.” Baxalta,
2018 WL
6304351, at *7–8 (emphasis in original).
The parties also disputed the construction of “antibody
fragment.” Baxalta proposed that the term be construed as
“[a] portion of a molecule having a specific amino acid se-
quence comprising two heavy chains (H chains) and two
light chains (L chains).”
Id. at *12. Genentech argued it
should instead be construed as “[a] fragment of an antibody
which partially or completely lacks the constant region; the
term ‘antibody fragment’ excludes all other forms of anti-
body derivatives.”
Id. The district court, relying on a por-
tion of the written description reciting that “antibody
fragments . . . partially or completely lack the constant re-
gion” and identifying examples of fragments (Fv, Fab, Fab'
[and] F(ab)'2), construed “antibody fragment” as “a frag-
ment of an antibody which partially or completely lacks the
constant region; the term ‘antibody fragment’ excludes
bispecific antibodies.”
Id. at *12–13 (citing ’590 patent at
6:20–21).
Based on the district court’s constructions, the parties
stipulated to non-infringement of the asserted claims of the
’590 patent. The district court entered final judgment of
non-infringement of claims 1, 4, 17, and 19. Baxalta ap-
peals, arguing that the district court erroneously construed
the terms “antibody” and “antibody fragment.”
II. DISCUSSION
We review a district court’s claim construction de novo
“[w]here, as here, the intrinsic evidence alone determines
the proper claim construction.” Allergan Sales, LLC v.
Sandoz, Inc.,
935 F.3d 1370, 1373 (Fed. Cir. 2019) (citing
Teva Pharm. USA, Inc. v. Sandoz, Inc.,
574 U.S. 318, 332–
33 (2015)). “The words of a claim are generally given their
ordinary and customary meaning as understood by a per-
son of ordinary skill in the art when read in the context of
the specification and prosecution history.” Thorner v. Sony
Case: 19-1527 Document: 59 Page: 7 Filed: 08/27/2020
BAXALTA INC. v. GENENTECH, INC. 7
Comput. Entm’t Am. LLC,
669 F.3d 1362, 1365 (Fed. Cir.
2012).
A. “Antibody”
i. The Claims of the ’590 Patent
Claim 1 of the ’590 patent recites “[a]n isolated anti-
body or antibody fragment thereof that binds Factor IX or
Factor IXa and increases the procoagulant activity of Fac-
tor IXa.” Therefore, contrary to the district court’s con-
struction, nothing in the plain language of claim 1 limits
the term “antibody” to a specific antibody consisting of two
identical heavy chains and two identical light chains or an
antibody that only binds the antigen that induced its syn-
thesis or very similar antigens.
The dependent claims confirm that “antibody” is not so
limited. For example, dependent claim 4, recites “[t]he an-
tibody or antibody fragment according to claim 1, wherein
said antibody or antibody fragment is selected from the
group consisting of . . . a chimeric antibody, a humanized
antibody, . . . [and] a bispecific antibody.” Each of these
claimed “antibodies” falls outside of the district court’s con-
struction because each does not “only bind[] to the antigen
that induced its synthesis or very similar antigens.” 3 A
3 The ’590 patent explains that a humanized anti-
body has a structure of a human antibody but combines
non-human antibody portions, such as the complement de-
termining regions (CDRs), with human antibody portions.
’590 patent at 6:50–7:1. It explains that a chimeric anti-
body differs from a humanized antibody in that it com-
prises the entire variable regions of non-human origin in
combination with human constant regions.
Id. Finally, it
explains that a bispecific antibody has “two different bind-
ing specificities within one single molecule,” i.e., it can bind
two different antigens.
Id. at 7:32–38. It is undisputed
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8 BAXALTA INC. v. GENENTECH, INC.
“bispecific antibody” also does not satisfy the district
court’s construction of “antibody” because a bispecific anti-
body does not consist of two identical H chains and two
identical L chains. Dependent claim 19 further limits
claims 1 and 4 by claiming that the “antibody is a human-
ized antibody,” which again does not fall within the district
court’s construction of “antibody.”
The district court’s construction which excludes these
explicitly claimed embodiments is inconsistent with the
plain language of the claims. 4 See Intellectual Ventures I
LLC v. T-Mobile USA, Inc.,
902 F.3d 1372, 1378 (Fed. Cir.
2018); see also Ortho-McNeil Pharm., Inc. v. Mylan Labs.,
Inc.,
520 F.3d 1358, 1362 (Fed. Cir. 2008) (rejecting a con-
struction that would “render several dependent claims
meaningless”).
that humanized antibodies, chimeric antibodies, and
bispecific antibodies fall outside the district court’s con-
struction. See Genentech Resp. Br. at 1, 53; Baxalta Op.
Br. at 12.
4 Baxalta argues that the district court’s claim con-
struction is also inconsistent with dependent claims 7, 9,
11, 18, 21, and 22 because they require synthetic produc-
tion methods that do not “only bind[] to the antigen that
induced its synthesis or very similar antigens.” Baxalta
Op. Br. at 31–32. Baxalta also argues that the district
court’s construction excludes claimed embodiments in
claims 3 and 20, which recite that the antibody is an “IgG,
IgM, IgA or IgE antibody.” Genentech agrees that IgM and
IgA antibodies do not necessarily meet the district court’s
construction requiring that the antibody consist of two
identical H chains and two identical L chains. Genentech
Resp. Br. at 9, 36. We note that when a construction such
as this is inconsistent with the plain language of the claims
and the written description, it is incorrect.
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BAXALTA INC. v. GENENTECH, INC. 9
The district court rejected this inconsistency, suggest-
ing that the proper result here is “invalidation of the incon-
sistent claims rather than an expansion of the independent
claims.” Baxalta,
2018 WL 6304351, at *11. Similarly,
Genentech invites us to assume that the examiner simply
overlooked at least these dependent claim limitations when
he allowed the claims. See Genentech Resp. Br. at 53 and
Baxalta Inc. v. Genentech, Inc., No. 19-1527, Oral Arg. at
34:44–35:12, available at http://oralargu-
ments.cafc.uscourts.gov/default.aspx?fl=2019-1527.mp3
(counsel for Genentech explaining “we don’t have an an-
swer to why [bispecific antibodies are] there except that
they stood rejected and somehow got allowed”). Genentech
argues that because the patent defines the term “antibody”
in column 5, we should invalidate all dependent claims
which would not be consistent with that definition such as
claims 4 and 19. We do not agree. The plain language of
these dependent claims weighs heavily in favor of adopting
Baxalta’s broader claim construction. And as in Intellec-
tual Ventures I, we reject the district court’s construction
which renders dependent claims
invalid. 902 F.3d at 1378.
ii. The Written Description of the ’590 Patent
Under the heading “Antibodies and Antibody Deriva-
tives,” the patentee explains:
Antibodies are immunoglobulin molecules having a
specific amino acid sequence which only bind to an-
tigens that induce their synthesis (or its immuno-
gen, respectively) or to antigens (or immunogens)
which are very similar to the former. Each immu-
noglobulin molecule consists of two types of poly-
peptide chains. Each molecule consists of large,
identical heavy chains (H chains) and two light,
also identical chains (L chains).
’590 patent at 5:56–65. The district court determined that
this portion of the written description defined the term “an-
tibody.” While this is a plausible reading of the excerpt in
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10 BAXALTA INC. v. GENENTECH, INC.
isolation, claim construction requires that we “consider the
specification as a whole, and [] read all portions of the writ-
ten description, if possible, in a manner that renders the
patent internally consistent.” Budde v. Harley-Davidson,
Inc.,
250 F.3d 1369, 1379–80 (Fed. Cir. 2001). When con-
sidered in the context of the remainder of the written de-
scription and the claims, we read the excerpt in column 5
as a generalized introduction to antibodies rather than as
a definitional statement. We also note that these general
statements do not include terms we have held to be limiting
in other contexts such as “the present invention includes .
. .” or “the present invention is . . .” or “all embodiments of
the present invention are . . . .” Luminara Worldwide, LLC
v. Liown Elecs. Co.,
814 F.3d 1343, 1353 (Fed. Cir. 2016).
Beyond this general description in column 5, the writ-
ten description provides specific disclosures regarding
bispecific, chimeric, and humanized antibodies and meth-
ods of production thereof, all of which do not comport with
the district court’s construction. For example, the written
description explains that “[t]he inventive antibodies and
antibody derivatives and organic compounds derived there
from comprise . . . bispecific antibodies.” ’590 patent at
6:1–6. Both parties agree “bispecific antibodies” do not con-
sist of two identical H chains and two identical L chains
and thus fall outside the district court’s construction. See,
e.g., Baxalta Op. Br. at 30 n.16; Genentech Resp. Br at 1.
The written description further discloses that “antibodies
and antibody derivatives may also include . . . ‘technically
modified antibodies’ such as . . . chimeric or humanized an-
tibodies . . . . In these technically modified antibodies, e.g.,
a part or parts of the light and/or heavy chain may be sub-
stituted.” ’590 patent at 6:15–24. And the written descrip-
tion explains that “[t]he antibodies of the present invention
can be prepared by methods known from the prior art, e.g.
by conventional hybridoma techniques, or by means of
phage display gene libraries, immunoglobulin chain shuf-
fling or humanizing techniques.”
Id. at 7:65–8:3 (emphasis
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BAXALTA INC. v. GENENTECH, INC. 11
added). The written description, therefore, discloses syn-
thetic techniques for preparing antibodies such as human-
ized or chimeric antibodies, which are inconsistent with the
district court’s claim construction requirement that the an-
tibody “only binds to the antigen that induced its synthesis
or very similar antigens.” Recognizing that these disclosed
techniques for preparing the claimed antibodies would re-
sult in antibodies excluded by the district court’s construc-
tion, Genentech’s response was “I hesitate to say that that’s
a typo.” Baxalta, No. 19-1527 Oral Arg. at 37:02–38:26.
Genentech does not dispute that the written descrip-
tion discloses antibodies that fall outside the district
court’s construction, but rather argues that “there is no le-
gal problem with a claim construction that excludes certain
disclosed embodiments, where the specification otherwise
supports that construction.” Genentech Resp. Br. at 1,
60–61. To adopt Genentech’s construction, we would need
to invalidate several dependent claims, which according to
Genentech, the examiner overlooked in allowing, and to
conclude that preparation techniques for the claimed anti-
bodies included in the written description were disclosed in
error. See Baxalta, No. 19-1527 Oral Arg. at 31:37–32:26
(counsel for Genentech conceding that “[claim 19] and
claim 4 are inconsistent with the notion that column 5 is a
definition of ‘antibody’”). As discussed, column 5 is not
definitional, and the remainder of the written description
and claims do not support the district court’s construction.
The claim construction excluding these disclosed and
claimed embodiments is therefore incorrect.
iii. The Prosecution History of the ’590 Patent
The prosecution history does not, as the district court
suggests, “confirm[] the specification’s definition of anti-
body.” Baxalta,
2018 WL 6304351, at *7. We have recog-
nized that the prosecution history “often lacks the clarity
of the specification and thus is less useful for claim con-
struction purposes.” Phillips v. AWH Corp.,
415 F.3d 1303,
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12 BAXALTA INC. v. GENENTECH, INC.
1317 (Fed. Cir. 2005) (en banc). While a patentee cannot
recapture specific constructions disclaimed during patent
prosecution either through amendment or argument, we do
not apply the doctrine of prosecution history disclaimer
where the alleged disavowal is less than clear. Avid Tech.,
Inc. v. Harmonic, Inc.,
812 F.3d 1040, 1045 (Fed. Cir. 2016).
The district court’s analysis centered around the pa-
tentee’s amendment substituting the term “antibody frag-
ment” for “antibody derivative,” at the examiner’s
suggestion, to overcome an enablement rejection. See
J.A. 15987, 16008, 16012, 16017–21. Based on its previous
definition of “antibody derivatives” as “antibodies within
the column 5 definition that had been altered in some sig-
nificant way,” e.g., bispecific antibodies, Baxalta,
2018 WL
6304351, at *6–7, the district court determined that the
amendment from “antibody derivative” to “antibody frag-
ment” amounted to a disclaimer of antibody derivatives “in-
cluding bispecific antibodies, except antibody fragments.”
Id. at *7–8 (emphasis in original). Because we reject the
premise that the excerpt of column 5 is definitional, and do
not view the prosecution history as sufficiently clear and
unmistakable, we conclude that the prosecution history is
insufficient to overcome the meaning of “antibody” we dis-
cern from the claims and the written description.
First, there are no clear statements in the prosecution
history regarding what scope, if any, was given up when
the patentee substituted “antibody fragment” for “antibody
derivative.” “[I]n order for prosecution disclaimer to at-
tach, the disavowal must be both clear and unmistakable.”
3M Innovative Properties Co. v. Tredegar Corp.,
725 F.3d
1315, 1325 (Fed. Cir. 2013). Both parties agree that the
term “antibody derivative” is not a term that is commonly
used in the art. Baxalta,
2018 WL 6304351, at *6. It is
plausible, therefore, given the ambiguity regarding this
amendment, that the patentee was substituting a known
term at the suggestion of the examiner for a less commonly
used term in the art. In fact, the written description
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BAXALTA INC. v. GENENTECH, INC. 13
appears to use them almost interchangeably. See, e.g.,
’590 patent at 6:20–22 (identifying Fv, Fab, Fab', and
F(ab)’2 as examples of antibody fragments);
id. at 20:35–36
(identifying scFv and Fab as examples of antibody deriva-
tives);
id. at 30:15–17 (identifying Fab, F(ab)2, and scFv as
examples of antibody derivatives). The prosecution his-
tory, therefore, does not clearly establish disclaimer. Sec-
ond, the district court’s determination that the patentee
disclaimed antibody derivatives “including bispecific anti-
bodies, except antibody fragments” is inconsistent with the
examiner’s subsequent allowance of at least claim 4. As
explained above, claim 4 explicitly claims “a bispecific an-
tibody,” a claimed embodiment directly at odds with a dis-
claimer theory. The prosecution history, therefore, does
not support the district court’s construction of “antibody.”
The parties agree that Baxalta’s and Genentech’s pro-
posed constructions are recognized meanings of “antibody.”
We hold that the district court erred in selecting the nar-
rower construction, which is inconsistent with the written
description and the plain language of the claim. Consistent
with the claims and the written description, we instead
construe “antibody” as “an immunoglobulin molecule hav-
ing a specific amino acid sequence comprising two heavy
chains (H chains) and two light chains (L chains).”
B. “Antibody Fragment”
The district court construed “antibody fragment” as “a
fragment of an antibody which partially or completely
lacks the constant region.” The district court further spec-
ified that “the term ‘antibody fragment’ excludes bispecific
antibodies.” Baxalta,
2018 WL 6304351, at *12–13. Bax-
alta argues that the district court’s construction improp-
erly excludes bispecific antibodies and imports limitations
from the written description. For reasons related to our
construction of “antibody,” we hold that the district court
erred in construing “antibody fragment.” We construe that
term as “[a] portion of an immunoglobulin molecule having
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14 BAXALTA INC. v. GENENTECH, INC.
a specific amino acid sequence comprising two heavy
chains (H chains) and two light chains (L chains).”
The district court’s construction relied on the following
portion of the written description:
The term factor IX/IXa activating antibodies and
antibody derivatives may also include . . . e.g.,
“technically modified antibodies” such as synthetic
antibodies, chimeric or humanized antibodies, or
mixtures thereof, or antibody fragments which par-
tially or completely lack the constant region, e.g.
Fv, Fab., Fab' or F(ab) etc.
’590 patent at 6:15–22 (emphases added). But this excerpt
does not, as the district court suggests, define antibody
fragments as necessarily “partially or completely lack[ing]
the constant region.” Indeed, the standard for lexicography
is exacting, requiring the patentee to “‘clearly express an
intent’ to redefine a term.”
Thorner, 669 F.3d at 1365–66.
“[A]lthough the specification often describes very specific
embodiments of the invention, we have repeatedly warned
against confining the claims to those embodiments.” Phil-
lips, 415 F.3d at 1323. Here, the written description’s use
of “may also include,” “e.g.,” “such as,” and “etc.” makes
clear the patentee did not intend this excerpt of the written
description to define “antibody fragment.” Instead, we con-
strue “fragment” according to its plain and ordinary mean-
ing in light of the written description as a whole.
Accordingly, we construe “antibody fragment” to mean “a
portion of an antibody” as we have defined above, that is:
“a portion of an immunoglobulin molecule having a specific
amino acid sequence comprising two heavy chains
(H chains) and two light chains (L chains).”
III. CONCLUSION
We have considered the parties’ remaining arguments
and do not find them persuasive. Because the district court
erred in construing the terms “antibody” and “antibody
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BAXALTA INC. v. GENENTECH, INC. 15
fragment” and entered judgment of non-infringement
based on its erroneous constructions, we vacate and re-
mand for further proceedings consistent with the correct
constructions of the terms.
VACATED AND REMANDED
COSTS
Costs to Baxalta.
