  United States Court of Appeals
      for the Federal Circuit
                 ______________________

    APOTEX INC., a Canadian Corporation, AND
     APOTEX CORP., a Delaware Corporation,
             Plaintiffs-Appellants,

                            v.

    UCB, INC., a Delaware Corporation, AND
  KREMERS URBAN PHARMACEUTICALS, INC.,
           a Delaware Corporation,
              Defendants-Appellees,

                           AND

  SCHWARZ PHARMA, INC., a Delaware Corpora-
    tion, PADDOCK LABORATORIES, LLC, AND
              PERRIGO COMPANY,
                    Defendants.
              ______________________

                       2013-1674
                 ______________________

   Appeal from the United States District Court for the
Southern District of Florida in Nos. 0:12-cv-60706-DMM
and 0:12-cv-60707-DMM, Judge Donald M. Middlebrooks.
                ______________________

                Decided: August 15, 2014
                 ______________________

   ROBERT B. BREISBLATT, Katten Muchin Rosenman
LLP, of Chicago, Illinois, argued for plaintiffs-appellants.
2                                    APOTEX INC.   v. UCB, INC.



With him on the brief were ERIC C. COHEN, CRAIG M.
KUCHII, and MARTIN S. MASAR III; and HOWARD R. RUBIN
and CHRISTOPHER D. JACKSON, of Washington, DC.

    ADAM GAHTAN, White & Case LLP, of New York, New
York, argued for defendants-appellees. With him on the
brief were DIMITRIOS T. DRIVAS, CHRISTOPHER J. GLANCY,
AMIT H. THAKORE, and LAURA T. MORAN.
                ______________________

    Before REYNA, WALLACH, and HUGHES, Circuit Judges.
REYNA, Circuit Judge.
     Apotex Inc. and Apotex Corp. (collectively, “Apotex”)
appeal the decision of the United States District Court for
the Southern District of Florida finding that: (1) Apotex’s
U.S. Patent No. 6,767,556 (“the ’556 patent”) is unen-
forceable due to inequitable conduct; (2) Apotex is judi-
cially estopped from alleging infringement of the ’556
patent by the accused products; (3) the asserted claims
are indefinite; (4) Apotex disclaimed coverage of the
accused products from the scope of the ’556 patent’s
claims; and (5) Apotex is barred by laches from recovering
pre-suit damages. Apotex, Inc. v. UCB, Inc., 970 F. Supp.
2d 1297 (S.D. Fla. 2013). Because the district court did
not abuse its discretion in finding inequitable conduct, we
affirm the district court’s judgment on that basis.
                        BACKGROUND
                    A. The ’556 Patent
    The ’556 patent, titled “Pharmaceutical Compositions
Comprising Moexipril Magnesium,” is about ten years old.
The patent issued on July 27, 2004, from an application
that claims priority to a Canadian application filed on
April 5, 2000. Dr. Bernard Charles Sherman, founder
and chairman of Apotex, wrote the ’556 patent application
and is its sole inventor. Dr. Sherman leads the develop-
APOTEX INC.   v. UCB, INC.                                3



ment of Apotex’s drug formulations and manufacturing
processes, and has himself written approximately one
hundred patent applications for Apotex. He also directs
all litigation for Apotex.
     The ’556 patent is generally directed to a process for
manufacturing moexipril tablets. Moexipril is an angio-
tensin-converting enzyme (“ACE”) inhibitor used to treat
hypertension. Like other ACE inhibitors, Moexipril and
its acid addition salts (e.g., moexipril hydrochloride) are
susceptible to degradation and instability. To improve
stability, the ’556 patent discloses a process of making
moexipril tablets consisting mostly of moexipril magnesi-
um obtained by reacting moexipril or its acid addition
salts with an alkaline magnesium compound. ’556 patent
col. 2 ll. 53–56. This process is captured in claim 1, the
only independent claim of the ’556 patent:
   1. A process of making a solid pharmaceutical
   composition comprising moexipril magnesium,
   said process comprising the step of reacting moex-
   ipril or an acid addition salt thereof with an alka-
   line magnesium compound in a controlled manner
   in the presence of a sufficient amount of solvent
   for a predetermined amount of time so as to con-
   vert greater than 80% of the moexipril or moex-
   ipril acid addition salt to moexipril magnesium.
    In the preferred embodiment, moexipril hydrochloride
is reacted with magnesium hydroxide or the magnesium
salt of a weak acid (e.g., magnesium carbonate) to obtain
moexipril magnesium. See id. col. 2 l. 66–col. 3 l. 5. The
’556 patent explains that the reaction cannot be accom-
plished in dry form and must be carried out in the pres-
ence of a solvent. Id. col. 2 ll. 38–45. After the reaction
has occurred and the solvent has evaporated, the dried
material can be compressed into tablets. This process is
called “wet granulation” and has been known in the
pharmaceutical industry since at least the 1980s.
4                                    APOTEX INC.   v. UCB, INC.



                     B. The Prior Art
     Several methods for stabilizing ACE inhibitors in
general, and moexipril in particular, were known in the
prior art before Dr. Sherman filed the ’556 patent applica-
tion. U.S. Patent No. 4,743,450 (“the ’450 patent”), which
issued in 1998 to Warner-Lambert, discloses a method for
stabilizing an ACE inhibitor using alkaline magnesium
compounds. ’450 patent col. 3 ll. 25–35. The examples in
the ’450 patent use quinapril as the ACE inhibitor and
magnesium carbonate as the alkaline stabilizer. Id. col. 4
l. 58–col. 5 l. 39. As in the ’556 patent, wet granulation is
the preferred technique for processing tablets according to
the ’450 patent. Id. col. 4 ll. 26–28.
    The two accused products in this case, Univasc and
Uniretic, are also prior art to the ’556 patent. Both prod-
ucts are moexipril tablets that have been sold in the
United States since 1995 and 1997, respectively. Univasc
and Uniretic are made in accordance with the process
described in the ’450 patent, which Defendant UCB, Inc.
licenses from Warner-Lambert and has listed in the
FDA’s Approved Drug Products with Therapeutic Equiva-
lence Evaluations (the “Orange Book”) for both products.
The manufacture of Univasc and Uniretic involves the
wet granulation of moexipril hydrochloride and magnesi-
um oxide.
     The ’556 patent discusses the ’450 patent and the
Univasc product. Specifically, the Background section
states that Univasc tablets contain moexipril hydrochlo-
ride and magnesium oxide, and are made in accordance
with the teachings of the ’450 patent. ’556 patent col. 2
ll. 16–22. This section also states that the moexipril
hydrochloride and alkaline magnesium compound are
capable of an acid-base reaction that is difficult to control
and results in uncertainty regarding the final composition
of the product. Id. col. 2 ll. 31–39.
APOTEX INC.   v. UCB, INC.                               5



    The ’556 patent also discusses a 1990 article by Gu et
al. 1 (“the Gu article”), which describes the chemistry
involved in stabilizing moexipril. Gu examined the deg-
radation of moexipril after mixing it with alkaline stabi-
lizers in both wet granulation and dry powder mixing (dry
granulation), concluding that only wet granulation stabi-
lizes moexipril. The Gu article theorizes that such stabi-
lization results from “neutralization” by the outer surface
of the granulated material and also possibly because “a
portion of the moexipril hydrochloride was converted to
the cation salts via granulation” (i.e., moexipril magnesi-
um was obtained). According to the Background section
of the ’556 patent, the Gu article teaches that only a
portion (if any) of the drug may be converted to moexipril
magnesium and that stabilization therefore occurs not
because of conversion, but because of the presence of the
alkaline stabilizing compound in the final product. ’556
patent col. 2 ll. 4–11.
                  C. The Prosecution History
    During prosecution before the U.S. Patent and
Trademark Office (“PTO”), the ’556 patent received three
obviousness rejections. First, the Examiner rejected the
claims based on the combination of the ’450 patent and
U.S. Patent No. 4,344,949, which discloses using moex-
ipril tablets to treat hypertension. In response, Dr.
Sherman’s counsel argued that the cited prior art did not
disclose a reaction, but disclosed only combining moexipril
hydrochloride and an alkaline magnesium compound. In
support, counsel submitted the Product Monograph for
Univasc and the portion of the Orange Book that lists
Univasc as being covered by the ’450 patent, stating:


        Leo Gu et al., Drug-Excipient Incompatibility
        1

Studies of the Dipeptide Angiotensin-Converting Enzyme
Inhibitor, Moexipril Hydrochloride: Dry Powder vs. Wet
Granulation, 7 Pharm. Res. 379 (1990).
6                                   APOTEX INC.   v. UCB, INC.



    Applicant herewith submits the Product Mono-
    graph for Univasc® (Moexipril Hydrochloride Tab-
    lets) wherein the tablets marketed by Schwarz
    Pharma (as listed in the FDA Orange Book as per
    the teachings of United States Patent No.
    4,743,450) include magnesium oxide; unreacted
    but combined and functioning as a stabilizer (see
    first page). The Examiner is referred to those
    pages. Full reconsideration is respectfully re-
    quested.
Joint Appendix (“J.A.”) at 12172 (emphasis added).
    The Examiner rejected the claims a second time, but
this time based on the combination of the ’450 patent and
the Gu article. The Examiner observed that it would have
been obvious to combine the ’450 patent’s teaching that
ACE inhibitor drugs can be stabilized with an alkaline
magnesium compound, with Gu’s teaching regarding
stabilization of moexipril hydrochloride via wet granula-
tion. In response, counsel again distinguished the prior
art on the basis that no reaction was taught:
    The Examiner alleges that Gu et al. renders obvi-
    ous the process of making moexipril magnesium
    and that Gu discloses a process of making a moex-
    ipril alkaline salt by allegedly reacting moexipril
    hydrochloride with an alkaline stabilizing agent.
    Respectfully no such reaction is taught. The com-
    ponents are merely combined and any reaction is
    insignificant to the desired end result.
Id. at 12223 (emphasis in original). Dr. Sherman’s coun-
sel once more referred the Examiner to the Product Mon-
ograph for Univasc and the Orange Book and argued that
Univasc includes magnesium oxide “unreacted but com-
bined.” Id. at 12224.
    Unconvinced, the Examiner issued a third and final
rejection on obviousness grounds based on Gu and the
APOTEX INC.   v. UCB, INC.                                7



’450 patent, finding that the neutralization taught by the
cited references constituted a reaction. Dr. Sherman’s
counsel appealed the final rejection to the PTO’s Board of
Appeals, arguing that the cited references merely taught
combining moexipril hydrochloride with an alkaline
stabilizing agent. Id. at 12249. Counsel again referred
the Board to the Product Monograph for Univasc and the
Orange Book and represented that Univasc, made accord-
ing to the ’450 patent, contained “unreacted but com-
bined” moexipril hydrochloride and magnesium oxide. Id.
at 12251.
    At the direction of Dr. Sherman, counsel also submit-
ted the expert declaration of Dr. Michael Lipp, who rein-
forced the representations regarding the prior art.
Specifically, Dr. Lipp explained that the function of a
stabilizer is to inhibit or prevent reactions that would
degrade the active ingredient, and that a stabilizer needs
to be unreacted to perform this function. See id. at 12288.
According to Dr. Lipp, a person of skill in the art would
therefore not expect a reaction to occur between the ACE
inhibitor and the alkaline stabilizer disclosed in the ’450
patent. Id. at 12289. Dr. Lipp relied on Univasc to sup-
port his conclusion:
   An additional example particularly relevant to the
   matter at hand is the UNVASC® [sic] moexipril
   hydrochloride formulation . . . . The product mon-
   ograph for the UNVASC [sic] moexipril hydrochlo-
   ride formulation lists moexipril hydrochloride as
   being present in the final formulation in addition
   to magnesium oxide as an alkaline stabilizer, as
   per the teachings of the ’450 patent which is listed
   on the FDA Orange Book for this formulation. As
   a result, in my opinion, a skilled formulator read-
   ing Harris et al. would not expect a reaction to oc-
   cur between an alkaline or saccharide stabilizer
   and an ACE inhibitor drug in the formulations
   disclosed therein.
8                                    APOTEX INC.   v. UCB, INC.



Id. at 12288–89.
    In a subsequent telephonic interview, the Examiner
and Dr. Sherman’s counsel agreed to incorporate into
claim 1 a limitation requiring “greater than 80%” conver-
sion of the moexipril or moexipril acid addition salt to
moexipril magnesium. As a result, the Examiner allowed
the ’556 patent claims on April 20, 2004. As reasons for
allowance, the Examiner stated:
    The primary reason for allowance is that the prior
    art does not disclose nor fairly suggest a process of
    making a pharmaceutical composition comprising
    moexipril magnesium, comprising the step of re-
    acting moexipril or an acid addition salt thereof
    with an alkaline magnesium compound so as to
    convert greater than 80% of the moexipril or
    moexipril acid addition salt to moexipril magnesi-
    um. Rather, the prior art teaches that only a por-
    tion of drug (if any) may be converted to the
    alkaline salt and that the stable product results
    entirely or primarily not from conversion to alka-
    line salts, but from stabilization of the moexipril
    hydrochloride by the presence of the alkaline stabi-
    lizing compound in the final product.
Id. at 12399 (emphasis added).
               D. District Court Proceedings
    Apotex filed suit on April 20, 2012, accusing UCB of
infringing claims 8–12 of the ’556 patent by manufactur-
ing and selling Univasc and Uniretic, as well as generic
versions thereof. Prior to conducting a jury trial on
infringement and invalidity, the district court held a
three-day bench trial on claim construction and UCB’s
equitable defenses.
    The district court ruled that the ’556 patent is unen-
forceable due to Dr. Sherman’s inequitable conduct before
the PTO. Specifically, the district court found that Dr.
APOTEX INC.   v. UCB, INC.                                 9



Sherman was aware that Univasc was made according to
his claimed process, concealed this knowledge from the
PTO, and misrepresented the nature of Univasc and the
prior art through his counsel’s arguments and Dr. Lipp’s
declaration. The district court also found that Dr. Sher-
man withheld relevant prior art and submitted results of
experiments that he never conducted.
    The district court relied on several pieces of evidence
in finding that Dr. Sherman was aware that Univasc
involved a reaction. For instance, Dr. Sherman conceded
during trial that, before filing the ’556 patent application,
he had a “strong suspicion” and a “belief” that Univasc
was made according to his claimed process. Also, on the
same day the application was filed, Dr. Sherman conduct-
ed tests comparing Univasc to an Apotex moexipril prod-
uct with no alkaline stabilizer. In his handwritten notes,
Dr. Sherman concluded that the Apotex product was
“much less stable than the magnesium salt,” implying at
least a suspicion that Univasc consisted of moexipril
magnesium. About a month later, Dr. Sherman’s suspi-
cion was confirmed by two Apotex scientists who produced
a detailed mass spectrometry report on Univasc and
concluded that moexipril in Univasc is “mainly present”
as moexipril magnesium.
    The court also found that Dr. Sherman was aware of,
and involved in, all decisions regarding prosecution of the
’556 patent application. The court noted that Dr. Sher-
man is highly familiar with patent prosecution and patent
enforcement litigation. Although Dr. Sherman attempted
to disclaim knowledge of the components of Univasc, the
prior art, and the statements made to the PTO by his
counsel, the district court did not find his testimony to be
credible. The district court observed that Dr. Sherman
selectively displayed at trial a lack of memory and re-
sponsibility that led the court to conclude he was not a
credible witness.
10                                   APOTEX INC.   v. UCB, INC.



    The district court also found that Dr. Sherman made
several misrepresentations to the PTO regarding the prior
art. In particular, Dr. Sherman misrepresented the
nature of Univasc and the ’450 patent by asserting that
the moexipril hydrochloride in Univasc was not reacted
but merely combined with an alkaline magnesium com-
pound. The district court also found that Dr. Sherman, in
the specification and through Dr. Lipp’s declaration,
mischaracterized the Gu article by asserting that only a
minor portion of the drug, if any, is converted to moexipril
magnesium. Lastly, the district court found that Dr.
Sherman lied in the ’556 patent application by including
certain examples of experiments that were never conduct-
ed. The court noted that each example is written in the
past tense as if it had occurred, but Dr. Sherman admit-
ted at trial that the experiments were made up in his
head.
    The district court further concluded that Dr. Lipp was
only hired to add legitimacy to Dr. Sherman’s misrepre-
sentations. The court found that Dr. Sherman failed to
inform Dr. Lipp of the true facts about Univasc and
shielded him from the truth, which resulted in a declara-
tion that Dr. Sherman knowingly submitted to the PTO to
perpetuate his mischaracterizations of the prior art. Dr.
Lipp testified that he was specifically asked to limit his
discussions to only the documents provided by Apotex,
which did not include any information regarding the tests
conducted on Univasc or Dr. Sherman’s knowledge of the
product.
    In addition to the misrepresentations, the district
court found that Dr. Sherman withheld relevant prior art
from the PTO. Specifically, PCT Application No. WO
99/62560, titled “Stabilization of Quinapril Using Magne-
sium Oxide” (“the ’560 PCT”), was cited by the PTO in a
2003 office action for U.S. Application No. 10/060,191
(“the ’191 application”), of which Dr. Sherman is also an
inventor. The ’560 PCT relates to a method for stabilizing
APOTEX INC.   v. UCB, INC.                                11



an ACE inhibitor drug, like quinapril, using magnesium
oxide, and the Examiner interpreted this reference as
disclosing a reaction between a hydrochloride salt and an
alkaline base. Given the similarities between the ’191
application and the ’556 patent and Dr. Sherman’s expe-
rience, the district court found that Dr. Sherman would
have known about the ’560 PCT and understood its rele-
vance to the prosecution of the ‘556 patent. The ’560 PCT,
however, was never disclosed to the Examiner handling
the prosecution of the ’556 patent.
     The district court found that the foregoing combined
misrepresentations and withholding of prior art were
material to the prosecution of the ’556 patent application.
Based on the Examiner’s reasons for allowance, the
district court concluded that the Examiner adopted Dr.
Sherman’s repeated misrepresentations verbatim and
would not have allowed the claims had he been aware
that Univasc contained moexipril magnesium. The dis-
trict court also found the ’560 PCT’s disclosure of a reac-
tion between a hydrochloride salt and an alkaline base to
be material because of the similarities between the ’191
application and the ’556 patent, and the fact that the ’560
PCT discloses the four basic steps of wet granulation
recited in claim 8 of the ’556 patent. Although the district
court found that the falsification of examples in the ’556
patent was alone not sufficiently material, it nonetheless
added to the materiality determination when viewed in
conjunction with other misrepresentations and omissions.
    In the alternative, the district court found that a find-
ing of but-for materiality was not necessary because Dr.
Sherman engaged in egregious misconduct during prose-
cution of the ’556 patent application. In addition to the
various misrepresentations made by Dr. Sherman, the
district court observed that Dr. Sherman abused the
patent system by targeting a competitor’s existing and
widely available product and seeking to obtain a patent
12                                   APOTEX INC.   v. UCB, INC.



on it through lies and deception for the purpose of suing
that competitor.
    Regarding intent, the district court found that the
single most reasonable inference that could be drawn
from the evidence was that Dr. Sherman intended to
deceive the PTO. The court based its determination on
Dr. Sherman’s overall pattern of misconduct and his poor
credibility at trial. The district court concluded that Dr.
Sherman intentionally violated his duty of candor not
only by making repeated misrepresentations to the PTO
during prosecution of the ’556 patent, but also by includ-
ing experiment results in the specification as if the exper-
iments had actually been conducted, and by purposely
shielding an expert from relevant information to obtain a
declaration that misinformed and led the Examiner to
finally allow the claims. The court also found that Dr.
Sherman’s demeanor and evasive testimony at trial were
evidence of his intent to deceive the PTO.
    The district court therefore held the ’556 patent unen-
forceable due to inequitable conduct. Additionally, the
court ruled in favor of UCB on its judicial estoppel and
laches equitable defenses, indefiniteness and claim con-
struction. The court entered final judgment against
Apotex on September 19, 2013. The jury trial on in-
fringement and invalidity was never held.
   Apotex filed a timely appeal.     We have jurisdiction
pursuant to 28 U.S.C. §1295(a)(1).
                       DISCUSSION
    We affirm the district court’s holding that the ’556 pa-
tent is unenforceable due to Dr. Sherman’s inequitable
conduct. The district court’s findings regarding materiali-
ty and intent are not clearly erroneous, and its ultimate
determination that Dr. Sherman breached his duty of
APOTEX INC.   v. UCB, INC.                                 13



candor, good faith, and honesty before the PTO was not
an abuse of discretion. 2
                         A. Materiality
     Clear and convincing evidence demonstrates that Dr.
Sherman engaged in material misconduct. First, Dr.
Sherman was actively involved in the prosecution of the
’556 patent and instigated the representations made on
his behalf by his counsel and Dr. Lipp. The ’556 patent’s
specification, written by Dr. Sherman, omits important
details regarding the prior art that were determined to
have been known to him. Record evidence shows that Dr.
Sherman’s counsel was in constant communication with
him during prosecution and kept him appraised of actions
taken by the PTO and arguments made in response,
including the representation that the prior art did not
involve a reaction. Indeed, Dr. Sherman directly instruct-
ed his counsel to continue pressing those arguments and
to bolster them through an expert declaration. We see no
reason to disturb the district court’s finding that Dr.
Sherman’s attempt to disclaim knowledge and responsi-
bility at trial was not credible. 3 The district court’s find-
ing that Dr. Sherman is responsible for the alleged
misconduct is not clearly erroneous.
    Second, Dr. Sherman made affirmative misrepresen-
tations of material facts. Apotex’s internal tests showed
that moexipril in Univasc is “mainly present” as moexipril



    2   Aventis Pharma S.A. v. Hospira, Inc., 675 F.3d
1324, 1334 (Fed. Cir. 2012); Symantec Corp. v. Computer
Assocs. Int’l, Inc., 522 F.3d 1279, 1296 (Fed. Cir. 2008).
    3   See Apotex, 970 F. Supp. 2d at 1310 n.23; see also
LNP Eng’g Plastics, Inc. v. Miller Waste Mills, Inc., 275
F.3d 1347, 1361 (Fed. Cir. 2001) (“This court may not
reassess, and indeed is incapable of reassessing, witness
credibility and motive issues on review.”)
14                                   APOTEX INC.   v. UCB, INC.



magnesium. Although the tests were conducted in 2001,
before the PTO issued its first rejection of the ’556 patent
claims, Dr. Sherman repeatedly asserted before the PTO
that the process of the ’450 patent used to manufacture
Univasc did not involve a reaction that would produce
moexipril magnesium. Years after issuance of the patent,
as part of its infringement case, Apotex confirmed
through Nuclear Magnetic Resonance (NMR) testing that
Univasc indeed contains more than 80% moexipril mag-
nesium. Dr. Sherman’s assertions during prosecution
regarding the absence of moexipril magnesium in Univasc
were false.
    Third, Dr. Sherman’s misconduct was “but-for mate-
rial” to the issuance of the ’556 patent. The Examiner’s
rejections were based on the very same prior art that is
the subject of Dr. Sherman’s misrepresentations. The
Examiner allowed the claims only after being convinced
that the prior art moexipril tablets were stable not from
conversion to moexipril magnesium (i.e., a reaction), but
because the alkaline stabilizer was combined and re-
mained present in the final product without reacting with
the moexipril. See J.A. at 12399. Dr. Lipp’s declaration
was instrumental in this regard. The Examiner’s errone-
ous belief regarding the prior art corresponds precisely
with Dr. Sherman’s repeated misrepresentations made
through his counsel and the hired expert. We conclude
that the PTO would not have allowed the ’556 patent but
for Dr. Sherman’s misconduct.
    To be clear, we agree with Apotex that Dr. Sherman
had no duty to disclose his own suspicions or beliefs
regarding the prior art. 4 There is nothing wrong with
advocating, in good faith, a reasonable interpretation of



     4 See Mentor H/S, Inc. v. Med. Device Alliance, Inc.,
244 F.3d 1365, 1378 (Fed. Cir. 2001).
APOTEX INC.   v. UCB, INC.                               15



the teachings of the prior art. 5 The misconduct at issue,
however, goes beyond failing to disclose a personal belief
or alternative interpretations of the prior art; here, Dr.
Sherman affirmatively and knowingly misrepresented
material facts regarding the prior art.
    Because we affirm the district court’s finding that the
misrepresentations regarding the prior art were but-for
material, we need not decide whether Dr. Sherman’s
conduct rises to the level of egregious misconduct such
that materiality could have been presumed. 6 We also
need not address the materiality of Dr. Sherman’s failure
to disclose the ’560 PCT or his falsification of examples in
the ’556 patent. We note, however, that Dr. Sherman’s
actions, at a minimum, come close to the type of affirma-
tive misconduct that in Therasense we held could justify
finding inequitable conduct without showing but-for
materiality. We find particularly significant and inexcus-
able the fact that Dr. Sherman arranged for the prepara-
tion and submission of an expert declaration containing
false statements instrumental to issuance of the patent.
                             B. Intent
    We affirm the district court’s finding that clear and
convincing evidence establishes Dr. Sherman’s intent to
deceive the PTO. The district court did not clearly err in
finding that Dr. Sherman knew, or at least had a strong
suspicion, that he was seeking to patent the very same
process used to obtain an already existing and widely
available drug. As of the filing of the ’556 patent applica-
tion, Dr. Sherman was aware that some of the assertions
he made in the specification regarding the prior art were



   5   See Rothman v. Target Corp., 556 F.3d 1310,
1328–29 (Fed. Cir. 2009).
   6   See Therasense, Inc. v. Becton, Dickinson and Co.,
649 F.3d 1276, 1292–93 (Fed. Cir. 2011) (en banc).
16                                    APOTEX INC.   v. UCB, INC.



at least misleadingly incomplete, if not plainly inaccurate.
Additionally, Dr. Sherman admitted that he never per-
formed the experiments described in the ’556 patent, and
yet he drafted the examples in the specification entirely in
past-tense language. See ’556 patent col. 5 l. 1–col. 6 l. 16.
Dr. Sherman was also aware that additional misrepresen-
tations were made on his behalf to the PTO, and directed
his counsel to bolster those misrepresentations by procur-
ing and submitting the declaration of an expert who was
deliberately shielded from the truth.
    Apotex argues that merely advocating a particular in-
terpretation of the prior art cannot support an inference
of deceptive intent. But Dr. Sherman’s statements were
not mere advocacy for a preferred interpretation; his
statements were factual in nature and contrary to the
true information he had in his possession. It is immateri-
al that, at that time, Dr. Sherman had no direct
knowledge of UCB’s actual manufacturing process or had
determined the exact amount of moexipril magnesium
present in Univasc. He knew enough to recognize that he
was crossing the line from legitimate advocacy to genuine
misrepresentation of material facts. In the aggregate, Dr.
Sherman’s conduct evidences a pattern of lack of candor.
We agree with the district court that deceptive intent is
the single most reasonable inference that can be drawn
from the evidence. 7
                        CONCLUSION
    The district court did not abuse its discretion in hold-
ing the ’556 patent unenforceable due to inequitable
conduct. In view of this, we need not reach the district
court’s rulings on claim construction, indefiniteness,



     7  See Therasense, 649 F.3d at 1290 (quoting Star
Scientific Inc. v. R.J. Reynolds Tobacco Co., 537 F.3d
1357, 1366 (Fed. Cir. 2008)).
APOTEX INC.   v. UCB, INC.                             17



laches and judicial estoppel.     The judgment in favor of
UCB is hereby
                             AFFIRMED
