  United States Court of Appeals
      for the Federal Circuit
                ______________________

                     UCB, INC.,
                   Plaintiff-Appellee

                           v.

YEDA RESEARCH AND DEVELOPMENT CO., LTD.,
            Defendant-Appellant
           ______________________

                      2015-1957
                ______________________

   Appeal from the United States District Court for the
Eastern District of Virginia in No. 1:14-cv-01038-LMB-
TCB, Judge Leonie M. Brinkema.
                ______________________

              Decided: September 8, 2016
                ______________________

   JAMES TRAINOR, White & Case LLP, New York, NY,
argued for plaintiff-appellee. Also represented by
CHRISTOPHER J. GLANCY, ADAM GAHTAN, ROBERT
COUNIHAN, DIMITRIOS T. DRIVAS, JOHN PADRO.

     NICHOLAS P. GROOMBRIDGE, Paul, Weiss, Rifkind,
Wharton & Garrison LLP, New York, NY, argued for
defendant-appellant. Also represented by REBECCA FETT,
CATHERINE NYARADY, DANIEL KLEIN, WILLIAM S. O'HARE
III.
                ______________________
2             UCB, INC.   v. YEDA RESEARCH AND DEVELOPMENT



    Before NEWMAN, LOURIE, and CHEN, Circuit Judges.
NEWMAN, Circuit Judge.
    In this declaratory judgment action, UCB, Inc. sued
Yeda Research and Development Co. in the United States
District Court for the Eastern District of Virginia, re-
questing a declaration that UCB’s Cimzia® brand anti-
body does not infringe Yeda’s U.S. Patent No. 6,090,923
(“the ’923 Patent”); UCB also sought a declaration that
the ’923 Patent is invalid. Yeda counterclaimed for in-
fringement. The district court granted summary judg-
ment of non-infringement, holding that, based on the
specification and prosecution history, the monoclonal
antibodies claimed in the ’923 patent are not infringed by
the chimeric or humanized antibodies of the Cimzia®
product. 1 We affirm the district court’s judgment.
                      BACKGROUND
     The ’923 Patent describes and claims a monoclonal
antibody that binds a defined human cytotoxin. Claim 1
is representative:
    1. A monoclonal antibody which specifically binds
    a human cytotoxin having a molecular weight of
    about 17,500 as determined by polyacrylamide gel
    electrophoresis, said cytotoxin being obtainable
    from stimulated human monocytes, said cytotoxin
    being further characterized by exhibiting a cyto-
    toxic effect on cycloheximide-sensitized SV-80
    cells and by being obtainable in a state of en-
    hanced purity by adsorption of the cytotoxin from
    an impure preparation onto controlled pore glass




    1  UCB, Inc. v. Yeda Research and Dev. Co., 117 F.
Supp. 3d 755 (E.D. Va. 2015) (“Dist. Ct. Op.”).
UCB, INC.   v. YEDA RESEARCH AND DEVELOPMENT               3



    beads, and subsequent desorption of the cytotoxin
    in a state of enhanced purity.
’923 Patent, col. 6, ll. 54-63. The question is whether the
monoclonal antibody of claim 1 includes chimeric or
humanized antibodies, when the patent specification
describes only murine (mouse) monoclonal antibodies.
Yeda argues that since chimeric monoclonal antibodies
were known at the time the ’923 priority application was
filed in 1984, the claims should be construed to cover such
chimeric antibodies, as well as humanized antibodies.
UCB responds that the prosecution history prohibits
coverage of chimeric and humanized antibodies, and that
claim 1 cannot be construed to cover those types of anti-
bodies.
     The ’923 specification states that the “CT [cytotoxin]
can be isolated by the use of monoclonal antibodies
against such CT which can be obtained from mice injected
with partially purified or crude preparations of CT.” Col.
1, l. 66–col. 2, l. 1. The specification states that “a mono-
clonal antibody specific for CT . . . is produced by such
hybridoma cell lines and is used for isolating CT in sub-
stantially homogenous purified form.” Col. 2, ll. 6–9. The
specification presents examples of isolating, partially
purifying, and characterizing the cytotoxin, raising and
purifying the mouse monoclonal antibody, and using this
mouse antibody to bind the cytotoxin.
    The claims as originally filed described the antibody
as a “monoclonal antibody,” but during a lengthy prosecu-
tion Yeda first limited all the claims to murine antibodies,
and then sought to remove this limitation, stating:
    New claims 41 and 42 are being submitted here-
    with in order to present claims identical to pres-
    ently appearing claims 38 and 39 without
    requiring that the monoclonal antibodies be mu-
    rine monoclonal antibodies. Arguments have pre-
    viously been made in this prosecution history that
4              UCB, INC.   v. YEDA RESEARCH AND DEVELOPMENT



    the recitation of “murine” with respect to the
    monoclonal antibody helps to distinguish the pre-
    sent claims over the references such as Matthews
    and Wallace which disclose obtaining rabbit poly-
    clonal antibodies. However, it is now believed
    that recitation of “murine” is unduly limiting and
    that claims 41 and 42 are allowable for the same
    reasons as argued in applicants’ amendment of
    April 21, 1998 with respect to claims 38 and 39.
Amendment letter of June 30, 1998 at 2.
    The examiner rejected the new claims 41 and 42, on
the ground that the specification did not “provide enable-
ment for the claimed ‘monoclonal antibodies’ from a broad
range of species.” Office Action of Sept. 10, 1998 at 3.
Yeda then argued that “the term should encompass
chimeric monoclonal antibodies,” stating:
    The term “monoclonal antibody” is defined . . . as
    “an antibody produced by culturing a single type
    of cell”, which “consists of a single species of im-
    munoglobulin molecules.” We do not believe that
    the term necessitates that the monoclonal anti-
    body be produced by the original hybridoma cell;
    the term should encompass chimeric monoclonal
    antibodies produced by a genetically engineered
    cell line.
Amendment letter of March 10, 1999 at 3 (footnote omit-
ted). The applicants’ letter continued:
    Applicants are particularly interested in protect-
    ing chimeric forms of their anti-cytotoxin mouse
    monoclonal antibodies. One of the reasons for
    their insistence on not limiting the claims to
    “mouse” monoclonal antibodies is uncertainty as
    to whether that would literally cover a humanized
    or chimeric derivative of a mouse monoclonal an-
    tibody. Any suggestions by the Examiner as to
UCB, INC.   v. YEDA RESEARCH AND DEVELOPMENT               5



    how to reconcile Applicants’ concerns with the Ex-
    aminer’s concerns as to enablement would be
    greatly appreciated.
Id. at 5–6. The amendment also added proposed claims
45-48, all of which expressly encompassed chimeric anti-
bodies.
    Thus Yeda argued to the Examiner that humanized or
chimeric derivatives of mouse monoclonal antibodies were
contemplated, and should be included in the claims. Yeda
submitted the declaration of Dr. Hartmut Engelmann,
stating that it was within the level of skill at the applica-
tion date to produce monoclonal antibodies from species
other than murine. Engelmann Declaration, May 18,
1999 at 2. The Declaration also cited two references that
preceded the effective filing date, describing mouse-
human chimeric antibodies. Id. at 3–4.
    The Examiner withdrew the rejection for lack of ena-
blement “in view of the applicant’s arguments and the
declaration of Hartmut Engelmann.” Office Action of
June 7, 1999 at 3. However, the Examiner rejected the
proposed new claims 45-48, which were specific to “rat,
hamster and human antibodies and chimeras thereof” and
to “chimeras of” mouse monoclonal antibodies and “non-
murine” monoclonal antibodies; the Examiner stated that
these claims added new matter and were not supported in
the specification. Id. The Examiner did not respond to
Yeda’s request for assistance in protecting the use of
chimeric or humanized antibodies in the claimed subject
matter.
    Yeda then cancelled all the claims that Yeda had pro-
posed to specify chimeric antibodies. The claim that
became patent claim 1, filed as claim 41, did not mention
chimeric antibodies, and had not been amended during
prosecution with respect to that aspect. On UCB’s motion
for summary judgment, the district court held that this
history prohibits construction of claim 1 to cover human-
6              UCB, INC.   v. YEDA RESEARCH AND DEVELOPMENT



ized and mouse-human chimeric antibodies, and thus the
court granted summary judgment of non-infringement.
                           DISCUSSION
    The issue on summary judgment was presented as a
question of claim construction. Claim construction is a
matter of law, based on underlying facts. Teva Pharm.
USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831 (2015). Sum-
mary judgment may be appropriate when there is no
genuine dispute as to any material fact and the movant is
entitled to judgment as a matter of law. Fed. R. Civ. P.
56; Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 247–48
(1986).
    The district court construed “monoclonal antibody,” as
used in the ’923 patent specification and claims, to mean
“a homogenous population of a single type of antibody
produced via hybridoma and not including chimeric or
humanized antibodies.” Dist. Ct. Op. at 774. We agree
that the prosecution history requires this construction, for
the scope now sought by Yeda was requested of the Exam-
iner, and refused on the ground of new matter. Yeda
argues that present claim 1 was never rejected on this
ground; Yeda states that only the specific species claims
were deemed by the Examiner to contain new matter.
    The district court held that all the claims, correctly
construed, exclude chimeric or humanized antibodies, the
court stating that “[e]xamination of the prosecution
history reveals that for the first ten years of prosecution,
neither Yeda nor the examiner understood the term
‘monoclonal antibodies’ to include chimeric or humanized
antibodies. Like the evidence in the specification, the
prosecution history weighs towards a construction of
‘monoclonal antibodies’ which does not include chimeric or
humanized antibodies.” Dist. Ct. Op. at 770. On this
ground, the court found non-infringement.
UCB, INC.   v. YEDA RESEARCH AND DEVELOPMENT              7



    Yeda argues that the district court erred in construing
the claims to find non-infringement, instead of construing
the claims objectively. Yeda states that the “claims
should not be construed with the goal of including or
excluding the accused product.” Yeda Br. 38. Yeda points
out that claim 1 does not mention any particular mono-
clonal antibody or species of chimera, and should not be
limited to the examples in the specification. Yeda states
that every embodiment need not be specifically described
and claimed to be within the scope of a generic term in a
claim.
    Yeda is correct in that generic terms in claims are
construed in light of that which is already known. How-
ever, the content of the specification and actions and
arguments during prosecution must also be considered, in
defining the scope of a generic term in a claim. See Ad-
vance Transformer Co. v. Levinson, 837 F.2d 1081, 1083
(Fed. Cir. 1988) (“Positions taken in order to obtain allow-
ance of an applicant’s claims are pertinent to an under-
standing and interpretation of the claims that are granted
by the PTO . . . and may work an estoppel as against a
subsequent different or broader interpretation.”).
     During prosecution, Yeda submitted new claims spe-
cific to “rat, hamster and human antibodies and chimeras
thereof” as well as claims specifically encompassing
“chimeras of” mouse monoclonal antibodies and “nonmu-
rine” monoclonal antibodies. Yeda argued that its inven-
tion is not limited to murine antibodies to human
cytotoxin, and “should encompass chimeric monoclonal
antibodies produced by a genetically engineered cell line.”
Amendment Letter of March 10, 1999 at 2, 3. The Exam-
iner rejected the proposed claims on the ground of new
matter not supported in the specification. Yeda then
withdrew the proposed specific claims, and the applica-
tion was passed to issuance. The district court held that
Yeda cannot now obtain a claim construction that recov-
ers claim scope that was yielded in order to obtain issu-
8              UCB, INC.   v. YEDA RESEARCH AND DEVELOPMENT



ance of the patent, and construed the claims as excluding
chimeric and humanized antibodies.
    Yeda argues that this construction is incorrect at least
as to claim 1, which recites “monoclonal antibody” but
does not specify any specific form or source of antibody.
Yeda states that chimeric or humanized monoclonal
antibodies were known at the time its priority application
was filed, December 20, 1984, and thus should be includ-
ed in the monoclonal antibodies of claim 1. Yeda present-
ed a publication of Morrison dated November 1, 1984, that
describes chimeric antibodies, and cited a December 8,
1984, Nobel Prize speech by César Milstein referring to
chimeric antibodies. The district court responded to these
arguments, stating: “At best, these references establish
that scientists knew of chimeric antibodies in November
1984. Establishing that chimeric antibodies existed in
1984, however, is different from establishing that a per-
son of ordinary skill in the art would have understood
chimeric antibodies to be monoclonal antibodies in 1984.”
Dist. Ct. Op. at 772.
     The district court concluded that “the extrinsic evi-
dence relied upon by Yeda’s experts does not support the
conclusion that the understanding of ‘monoclonal antibod-
ies’ in 1984 included either chimeric or humanized anti-
bodies.” Id. The district court found that “for the first ten
years of prosecution, neither Yeda nor the examiner
understood the term ‘monoclonal antibodies’ to include
chimeric or humanized antibodies.” Id. at 770. The
district court held that Yeda’s unsuccessful attempt to
claim chimeras in the pending application, with acquies-
cence in the examiner’s rejection on the ground of new
matter not supported by the specification, prohibited now
obtaining a claim construction that chimeric antibodies,
or equivalents thereof, are described in the specification
and included in the claims.
UCB, INC.   v. YEDA RESEARCH AND DEVELOPMENT             9



    Yeda argues that absent a narrowing amendment to
the proposed claim that is now claim 1, there can be no
prosecution estoppel to the scope of claim 1, merely be-
cause some proposed different claims were rejected by the
examiner and then dropped by the applicant. That is not
a correct general principle. Although each claim in a
patent warrants independent consideration in light of its
particular facts and history, the general rule is that a
patent applicant cannot later obtain scope that was
requested during prosecution, rejected by the Examiner,
and then withdrawn by the applicant.
    Such estoppel was reasonably applied to claim 1 by
the district court, although claim 1 had not been amend-
ed. In Builders Concrete, Inc. v. Bremerton Concrete
Products Co., 757 F.2d 255, 259 (Fed. Cir. 1985), the court
rejected the argument that “file wrapper estoppel cannot
arise without an amendment,” and explained that the
“position must be evaluated in the context of this specific
case.” In Wang Laboratories, Inc. v. Mitsubishi Electron-
ics America, Inc., 103 F.3d 1571, 1578 (Fed. Cir. 1997),
the court again explained: “We examine the statements
and actions of the patentee before the PTO during prose-
cution . . . and ask what a competitor reasonably may
conclude the patentee surrendered to gain issuance of the
patent.” (internal citations omitted).
    We conclude that the district court correctly applied
the law, and we affirm the holding that Yeda is estopped
from including chimeric and humanized antibodies within
the scope of the monoclonal antibodies claimed in the ’923
Patent.
                        AFFIRMED
