  United States Court of Appeals
      for the Federal Circuit
                ______________________

  MAYNE PHARMA INTERNATIONAL PTY. LTD.,
                Appellant

                           v.

         MERCK SHARP & DOHME CORP.,
                  Appellee

    ANDREI IANCU, UNDER SECRETARY OF
  COMMERCE FOR INTELLECTUAL PROPERTY
   AND DIRECTOR OF THE UNITED STATES
      PATENT AND TRADEMARK OFFICE
                  Intervenor
            ______________________

                      2018-1593
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2016-
01186.
                 ______________________

                Decided: June 21, 2019
                ______________________

    JACQUES SEMMELMAN, Curtis, Mallet-Prevost, Colt &
Mosle LLP, New York, NY, argued for appellant. Also rep-
resented by ELIOT LAUER, NICOLE MARIA MAZANITIS;
THOMAS K. HEDEMANN, Axinn Veltrop Harkrider, LLP,
Hartford, CT; JASON MURATA, Axinn, Veltrop & Harkrider
2    MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




LLP, San Francisco, CA; TERESA STANEK REA, Crowell &
Moring, LLP, Washington, DC.

   JENNIFER LORAINE SWIZE, Jones Day, Washington, DC,
argued for appellee. Also represented by JANE M. LOVE,
ROBERT TRENCHARD, Gibson, Dunn & Crutcher LLP, New
York, NY.

    MOLLY R. SILFEN, Office of the Solicitor, United States
Patent and Trademark Office, Alexandria, VA, argued for
intervenor. Also represented by THOMAS W. KRAUSE,
KAKOLI CAPRIHAN, FRANCES LYNCH, JOSEPH MATAL.
                ______________________

    Before LOURIE, DYK, and O’MALLEY, Circuit Judges.
LOURIE, Circuit Judge,
     Mayne Pharma International Pty. Ltd. (“Mayne”) ap-
peals from the final written decision of the U.S. Patent and
Trademark Office Patent Trial and Appeal Board (“the
Board”) in an inter partes review, concluding that claims 2,
6, and 9–14 of U.S. Patent 6,881,745 (“the ’745 patent”) are
unpatentable as anticipated or obvious. See Merck Sharp
& Dohme Corp. v. Mayne Pharma Int’l Pty. Ltd., No. IPR
2016-01186, at 2 (P.T.A.B. Dec. 18, 2017), J.A. 76–111 (“De-
cision”). For the reasons detailed below, we affirm.
                       BACKGROUND
    Mayne owns the ’745 patent, which discloses and
claims pharmaceutical compositions of azole antifungal
drugs that are practically insoluble in aqueous media. The
patent explains that insoluble drugs are difficult to formu-
late into dosage forms because of their low absorption and
poor bioavailability. It thus purports to provide a pharma-
ceutical composition addressing these shortcomings. At is-
sue here are claims 2, 6, and 9–14. Claim 9 is illustrative:
MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.       3



    A pharmaceutical composition, consisting essen-
    tially of:
        about 100 mg of an azole antifungal drug;
        and
        one or more polymer[s] having acidic func-
        tional groups; and
        optionally one or more additional ingredi-
        ents selected from the group consisting of a
        disintegrant, a diluent, a filler, an inert
        solid carrier, an inert solid matrix, a lubri-
        cant, a glidant, a colouring agent, a pig-
        ment, a flavour, water, ammonia, an
        alkaline agent, and methylene chloride,
        wherein in vivo the composition provides a
        mean CMAX of at least 100 ng/ml, after ad-
        ministration in the fasted state.
’745 patent col. 11 ll. 15–28 (emphasis added).
     Each claim at issue requires a pharmaceutical compo-
sition consisting essentially of about 100 mg of an azole an-
tifungal drug and at least one polymer having acidic
functional groups, wherein the composition exhibits cer-
tain pharmacokinetic properties in vivo. Specifically,
claims 2, 9, 10, and 11 require that the in vivo composition
provides a mean CMAX of at least 100 ng/ml, while claims 6,
12, 13, and 14 require a mean AUC of at least 800 ng.h/ml.
    Merck Sharp & Dohme Corp. (“MSD”) petitioned for in-
ter partes review of claims 1–3, 5–7, and 9–14 of the ’745
patent. The Board instituted review on three grounds, 1



    1   The Board did not institute on all grounds in MSD’s
petition. Although the Board’s decision is inconsistent with
SAS Institute, Inc. v. Iancu, 138 S. Ct. 1348 (2018), the
4    MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




but, because Mayne cancelled claims 1, 3, 5, and 7 during
the proceedings, the Board only considered two grounds in
its final written decision: anticipation of claims 2, 6, 9, 11,
12, and 14 by Kai 2 and obviousness of claims 2, 6, and 9–
14 over Kai, Sangekar, 3 and Babcock. 4 The Board held
each of the challenged claims unpatentable.
     On appeal Mayne argues that the Board erred in two
respects: (1) by instituting review when the petition should
have been found time-barred under 35 U.S.C. § 315(b) and
(2) by declining to limit the claims to nontoxic compositions
that produce the claimed pharmacokinetic profile in hu-
mans.
     We begin by reviewing Mayne’s time-bar arguments,
which pervade the proceedings below. Mayne first raised
its argument at institution, urging the Board to reject the
petition because Merck & Co., Inc. (“MCI”) should have
been identified as a real party in interest. Based on the
record at the time, however, the Board was not persuaded
that MCI was a real party in interest and denied Mayne’s
request. Mayne then requested rehearing of the institution
decision, arguing that the Board abused its discretion by




parties do not seek and have waived entitlement to any
SAS-based relief. See Mylan Pharm. Inc. v. Research Corp.
Techs., Inc., 914 F.3d 1366, 1377 (Fed. Cir. 2019); PGS Ge-
ophysical AS v. Iancu, 891 F.3d 1354, 1362–63 (Fed. Cir.
2018).
    2 T oshiya Kai et al., Oral Absorption Improvement of

Poorly Soluble Drug Using Solid Dispersion Technique, 44
CHEM. PHARM. BULL. 568–71 (1996) (“Kai”).
    3   PCT Publication No. (WO) 98/00113 A1 (“Sange-
kar”).
    4   European Patent Office Publication No. (EP) 1 027
886 A2 (“Babcock”).
MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.         5



failing to find the petition incomplete and time-barred, but
the Board again rejected Mayne’s challenge.
    Mayne then raised the real-party-in-interest issue dur-
ing the review proceedings. On a more developed record,
the Board determined that “permitting Petitioner to up-
date its mandatory notice to include MSD’s parent com-
pany, Merck & Co., Inc., as a real party in interest in this
matter—without affecting the Petition’s filing date—
[would] promote[] the core functions described in the Trial
Practice Guide with respect to [real parties in interest], and
serve[] the interests of justice.” Merck Sharp & Dohme
Corp. v. Mayne Pharma Int’l Pty Ltd., No. IPR2016-01186,
2017 WL 6398319, at *2 (P.T.A.B. Dec. 13, 2017). Accord-
ingly, the Board ordered Petitioner to amend its mandatory
notice to name MCI. Because the Board ordered MCI’s ad-
dition to the petition without altering the filing date, it re-
jected Mayne’s continued argument concerning the time
bar as moot in its final written decision. J.A. 108.
    On the merits, Mayne argued to the Board that it
should construe the claims as limited to nontoxic composi-
tions that produce the claimed pharmacokinetic profile in
humans. It argued for this narrow claim scope based on
the terms “azole antifungal drug” and “pharmaceutical
composition,” and the “wherein” clauses that detail phar-
macokinetic parameters for the apparent purpose of ex-
cluding the Kai prior art.
    The Board disagreed and found that the claims were
not limited to therapeutically beneficial nontoxic drugs in
construing the claim terms “azole antifungal drug,” and
“pharmaceutical composition.” The Board pointed to the
specification, which discusses both itraconazole and sa-
perconazole as “azole antifungal drugs” suitable for “phar-
maceutical composition,” without commenting on their
adverse effects, potential or otherwise. J.A. 99–100.
    As for the “wherein” clauses, the Board found the
claims encompassed compositions meeting the claimed
6       MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




parameters in both humans and animals. Each wherein
clause recites that the parameters are achieved “in vivo.”
For the definition of “in vivo,” the Board turned to the spec-
ification, which states that “[t]he term ‘in vivo’ in general
means in the living body of a plant or animal . . . .” J.A. 92
(quoting ’745 patent col. 3 ll. 37–39). The Board was per-
suaded that this definition in the specification was “con-
sistent with the plain meaning of the term ‘in vivo’ as it
would have been understood one of ordinary skill in the art
at the time of the invention . . . .” Id. Although the speci-
fication disclosed results of a specific clinical trial involving
administration of a particular azole, itraconazole, to a par-
ticular animal, humans, the Board declined to import lim-
itations from the specification into the claim language.
    Following these constructions, the Board considered
whether Kai anticipated the claims. Kai discloses a solid
dispersion technique for improving the bioavailability of a
triazole antifungal agent, MFB-1041. 5 First, MFB-1041 is
dissolved in a mixed solvent of dichloromethane and etha-
nol. A polymer is then added to the solution at a drug-to-
polymer ratio of from 1:1 to 1:5. Several polymers are dis-
closed, including hydroxypropylmethylcellulose phthalate
(HP-55), the preferred polymer of the ’745 patent. The so-
lution is spray-dried, yielding a powder that was adminis-
tered to beagle dogs under fasted conditions. Table 1,




    5   MFB-1041 is (+)-2-(2,4-difluorophenyl)-3-methyl-1-
(1H-1,2,3-triazol-1-yl)-3-[6-(1H-1,2,4-triazol-1-yl)pyri-
dazin-3-ylthio]butan-2-ol.
MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.        7



reproduced below, discloses the pharmacokinetic profile of
MFB-1041 upon administration:




J.A. 2446.
    Based on the above data, the Board found that Kai dis-
closes a composition consisting essentially of 100 mg of an
azole and a polymer with acidic functional groups, which
provides a mean CMAX of at least 100 ng/ml and a mean
AUC of at least 100 ng.h/ml in vivo after administration in
the fasted state. Over Mayne’s objection, the Board also
found MFB-1041 to be a drug, and a composition contain-
ing the MFB-1041 to be a pharmaceutical composition. Ac-
cordingly, the Board found that all of the limitations of
claims 2, 6, 9, 11, 12, and 14 were met and hence they are
anticipated by Kai.
    Regarding the second prior art ground, additionally in-
volving claims 10 and 13, in addition to the arguments the
Board had already rejected regarding anticipation by Kai,
Mayne argued only that the petition did not articulate a
motivation to combine Kai, Sangekar, and Babcock. The
Board disagreed, finding that a person of skill would have
had a reason to place Kai’s solid dispersion powder into a
capsule with a reasonable expectation of successfully doing
so, because Sangekar teaches that a comparable composi-
tion comprising a solid solution of “tetrahydrofuran [sic] az-
ole antifungal” in a polymer matrix can be manufactured
in tablet or capsule form. J.A. 104. The Board also
8    MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




considered objective evidence of failure of others, copying,
praise, and commercial success, but found that the evi-
dence was not attributable to anything novel in the claims.
Accordingly, the Board found that claims 2, 6, and 9–14
would have been obvious over Kai in view of Sangekar and
Babcock.
     Mayne appealed. We have jurisdiction over the merits
of the final written decision under 35 U.S.C. §§ 141(c), 319,
and 28 U.S.C. § 1295(a)(4)(A). MSD contests our entitle-
ment to review the Board’s decision to permit its amend-
ment to its real-party-in-interest disclosure. The Patent
and Trademark Office (the “PTO”) intervened under 35
U.S.C. § 143 in support of MSD’s position on entitlement.
                         DISCUSSION
                       I. The Time Bar
    Mayne first argues that the Board should not have in-
stituted review because the petition was time-barred under
35 U.S.C. § 315(b). Mayne contends that the PTO’s clear
and unambiguous rules provide that a petition can only be
considered and accorded a filing date after all real parties
in interest are identified. Appellant’s Br. 24 (citing 37
C.F.R. § 42.104).      Specifically, Mayne submits that
§ 42.104(c), which permits amendments for clerical or ty-
pographical mistakes, provides the only avenue for amend-
ing a petition without impacting its filing date and contests
the Board’s use of the late action rule in § 42.5(c)(3) to allow
the amendment in the interest of justice, noting that MSD’s
amendment did not relate to a clerical or typographical
mistake.
    According to Mayne, because MCI was a real party in
interest, the Board could not allow a correction without re-
setting the petition’s filing date to the date of the amend-
ment, which it did not do. Because MSD did not name MCI
until December 14, 2017, more than a year after the service
MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.        9



of Mayne’s complaint against it, Mayne maintains that the
petition should have been time-barred.
     MSD responds that this court may not hear Mayne’s
challenge to the petition’s real-party-in-interest disclosure.
It suggests that Mayne’s arguments involve an AIA man-
datory disclosure provision, 35 U.S.C. § 312(a)(2), that
should be read with § 314(d), which renders unappealable
a determination by the Director whether to institute re-
view “under this section.” According to MSD, Cuozzo Speed
Technologies, LLC v. Lee, 136 S. Ct. 2131 (2016), held that
compliance with § 312(a)(3) was unreviewable, Appellee’s
Br. 25, and likewise § 312(a)(2) real-party-in-interest iden-
tifications should be unreviewable as well, id. at 26.
     If the Board’s decision is reviewable, however, MSD ar-
gues that it should be affirmed. It believes that the Board
acted well within its discretion to permit its amendment
without altering the filing date. MSD submits that the Di-
rector is empowered to provide procedures for identifying
real parties in interest and has the authority to permit sub-
sequent amendment. In support of that position, it notes
that this court stated in Wi-Fi One, LLC v. Broadcom
Corp., 878 F.3d 1364 (Fed. Cir. 2018), that the Director can
and has allowed a petitioner to add a real party in interest
if the petition fails to comply with § 312(a)(2). Appellee’s
Br. 33 (citing Wi-Fi One, 878 F.3d at 1374 n.9).
     In the circumstances of this case, MSD maintains that
its initial disclosure satisfied both purposes of the real-
party-in-interest requirement: the Board was able to iden-
tify conflicts, and MCI agreed to be bound by any estoppel
effect flowing from the inter partes review. MSD also sug-
gests that there was no prejudice to Mayne because the pe-
tition was filed within a year of Mayne’s district court
complaint naming both MCI and MSD. Finally, MSD ar-
gues that the Board furthered the public interest in effi-
cient review by allowing the amendment and limiting
additional, burdensome real-party-in-interest discovery.
10   MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




    The PTO, as intervenor, agrees with MSD’s first point
and contests our entitlement to review the Board’s deci-
sion. According to the PTO, this case does not involve the
application of the time bar of § 315(b), and we lack entitle-
ment to consider whether a petition complies with
§ 312(a)(2). Alternatively, the PTO argues that, if this
court can review this issue, the Board did not err in per-
mitting Mayne’s amendment because the purposes of the
time bar—application of the estoppel and identification of
Board conflicts—were served here and the Board’s action
was permissible under its late-action rule of 37 C.F.R.
§ 42.5(c)(3).
    We conclude that we need not address the issue of ap-
pealability. The scope of review of a final written decision
and the limit on that review imposed by the appeal bar of
§ 314(d) are not jurisdictional issues. The appeal bar is not
characterized as jurisdictional in the statute, and the Su-
preme Court has told us to avoid characterizing rules as
jurisdictional where Congress has not “clearly stated that
the rule is jurisdictional.” Sebelius v. Auburn Reg’l Med.
Ctr., 568 U.S. 145, 153 (2013); accord Fort Bend Cty., Texas
v. Davis, 139 S. Ct. 1843, 1850 (2019) (stating that “when
Congress does not rank a [prescription] as jurisdictional,
courts should treat the restriction as nonjurisdictional in
character.” (alteration in original) (quoting Arbaugh v. Y &
H Corp., 546 U. S. 500, 515–16 (2006))). The nonjurisdic-
tional nature of most scope of review provisions was estab-
lished by the Supreme Court’s decision in Air Courier
Conference of America v. American Postal Workers Union
AFL-CIO, 498 U.S. 517, 523 n.3 (1991) (“The judicial re-
view provisions of the APA are not jurisdictional” (citing
Califano v. Sanders, 430 U.S. 99, 106–109 (1977))).
    Because we conclude that the Board committed no re-
versible error (whether or not it is appealable), we need not
decide the issue of appealability. See Lone Star Silicon In-
novations LLC v. Nanya Tech. Corp., No. 2018-1581, 2019
WL 2292485, at *7 (Fed. Cir. May 30, 2019) (explaining
MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.         11



that defects in statutory standing “do not implicate a
court’s subject-matter jurisdiction” (citing Lexmark Int’l,
Inc. v. Static Control Components, Inc., 572 U.S. 118, 128
n.4 (2014))).
    We now proceed to address the merits. In deciding
whether to permit MSD’s amendment, the Board consid-
ered its guidance in the Trial Practice Guide that the dis-
closure requirement assists members of the Board in
identifying conflicts and assures proper application of stat-
utory estoppel. Based on these “core functions” of the dis-
closure requirement, the Board reasoned that
    [a]bsent any indication of an attempt to circumvent
    estoppel rules, a petitioner’s bad faith, or prejudice
    to a patent owner caused by the delay, permitting
    a petitioner to amend a challenged [real-party-in-
    interest] disclosure while maintaining the original
    filing date promotes the core functions described in
    the Trial Practice Guide, while also promoting the
    “just, speedy, and inexpensive resolution of our
    proceedings.”
J.A. 65 (citing 77 Fed. Reg. 48,756, 48,759; then quoting 37
C.F.R. § 42.1(b)). Applying this rule, the Board found no
indication of intentional concealment, no bad faith on
MSD’s part, no attempt to circumvent the estoppel rules,
or any other material benefit to it in its delay in naming
MCI as real party in interest. Thus the Board permitted
MSD’s amendment in the interest of justice under
§ 42.5(c)(3).
    Congress enacted the America Invents Act (“AIA”) in
2011, replacing inter partes reexamination with inter
partes review. See Pub. L. No. 112-29, 125 Stat. 284 (2011).
The AIA authorizes the PTO to promulgate regulations
governing the administration of these proceedings, 35
U.S.C. § 316(a), and we review the PTO’s rulemaking pur-
suant to Chevron, U.S.A., Inc. v. Natural Resources Defense
Council, Inc., 467 U.S. 837 (1984). “[W]here a statute
12   MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




leaves a ‘gap’ or is ‘ambigu[ous],’ we typically interpret it
as granting the agency leeway to enact rules that are rea-
sonable in light of the text, nature, and purpose of the stat-
ute.” Cuozzo, 136 S. Ct. at 2142 (quoting United States v.
Mead Corp., 533 U.S. 218, 229 (2001)). When the Board
issues such rules, “[w]e accept the Board’s interpretation of
[them] unless that interpretation is ‘plainly erroneous or
inconsistent with the regulation.’” In re Sullivan, 362 F.3d
1324, 1326 (Fed. Cir. 2004) (quoting Eli Lilly Co. v. Bd. of
Regents of the Univ. of Wash., 334 F.3d 1264, 1266 (Fed.
Cir. 2003)).
    In excusing MSD’s late disclosure, the Board relied on
“interests of justice” language in 37 C.F.R. § 42.5(c)(3), its
late-action rule: “A late action will be excused on a showing
of good cause or upon a Board decision that consideration
on the merits would be in the interests of justice.”
     In applying § 42.5(c)(3), the Board did not plainly err
in finding that MSD’s amendment would serve the inter-
ests of justice. Both MSD and MCI agreed to be bound by
the estoppel effects flowing from the proceeding, and the
Board found that it was properly apprised of conflicts re-
lating to MCI from the identification of MSD. There was
no evidence suggesting that MSD intended to conceal
MCI’s identity. In fact, Mayne was aware of MCI because
MCI was a named defendant in parallel district court liti-
gation, and, had MSD named MCI as a real party in inter-
est in its original petition, Mayne would be in the same
position it is in now.
    Conversely, unwinding the proceedings based on a
strict view of the real-party-in-interest disclosure require-
ment would be at odds with the PTO policy expressed in
§ 42.1(b) that Part 42 “be construed to secure the just,
speedy, and inexpensive resolution of every proceeding.”
Accord Cuozzo, 136 S. Ct. at 2140 (“We doubt that Congress
would have granted the Patent Office [significant power to
revisit and revise earlier patent grants], including, for
MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.       13



example, the ability to continue proceedings even after the
original petitioner settles and drops out, § 317(a), if it had
thought that the agency’s final decision could be unwound
under some minor statutory technicality related to its pre-
liminary decision to institute inter partes review.”). On
this record, the Board did not plainly err in finding that
MSD’s amendment served the interest of justice.
    Mayne raises a separate argument that § 42.5(c)(3)’s
late-action rule cannot supplant § 42.104(c), which specifi-
cally governs the correction of petitions. Section 42.104(c)
provides that “[a] motion may be filed that seeks to correct
a clerical or typographical mistake in the petition,” and
that “[t]he grant of such a motion does not change the filing
date of the petition.” Neither party argues that the omis-
sion of MCI was a clerical or typographical error, so that
provision is inapplicable here.
     Mayne repeatedly suggests that § 42.104(c) provides
the sole means for correction of a petition, suggesting that
the PTO confirmed this understanding during notice-and-
comment rulemaking. Appellant’s Br. 25. Mayne is correct
that in August 2015, the PTO provided non-binding “guid-
ance” stating that the Office was “unable” to allow correc-
tion of non-clerical errors “without changing the filing
date.” 80 Fed. Reg. 50,720, 50,721. However, the Board
thereafter changed its practice. For example, in Elekta, the
Board held that it had discretion to permit a petitioner to
correct defective real-party-in-interest disclosures “with-
out changing the filing date.” Elekta Inc. v. Varian Med.
Sys., Inc., No. IPR 2015-01401, 2015 WL 9898990, at *5
(P.T.A.B. Dec. 31, 2015). Similarly, in Lumentum, a deci-
sion the Board has deemed precedential, the Board held
that it did not lose jurisdiction when a petition no longer
identifies all real parties in interest and that petitioner
could update its disclosure without vacating the petition’s
filing date. Lumentum Holdings, Inc. v. Capella Photonics,
Inc., No. IPR2015-00739, 2016 WL 2736005, at *3 (P.T.A.B.
Mar. 4, 2016). Indeed, as we noted in Wi-Fi One, “if a
14   MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




petition fails to identify all real parties in interest under
§ 312(a)(2), the Director can, and does, allow the petitioner
to add a real party in interest.” 878 F.3d at 1374 n.9. A
lapse in compliance does not preclude the Board from per-
mitting the lapse to be rectified, and we are unpersuaded
that § 42.104(c) provides the exclusive means for correcting
a petition.
    We have considered Mayne’s remaining arguments re-
garding MSD’s amendment and find them unpersuasive.
Accordingly, we conclude that the Board did not err in al-
lowing MSD to amend its disclosures to add MCI as a real
party in interest without altering the petition’s filing date.
                       II. The Merits
     Mayne next challenges two aspects of the Board’s claim
construction, arguing that, under its proffered, narrower
constructions, the claims should be patentable. We review
the Board’s ultimate claim constructions de novo and its
underlying factual determinations involving extrinsic evi-
dence for substantial evidence. Skky, Inc. v. MindGeek,
s.a.r.l., 859 F.3d 1014, 1019 (Fed. Cir. 2017), cert. denied,
138 S. Ct. 1693 (2018) (citing Microsoft Corp. v. Proxyconn,
Inc., 789 F.3d 1292, 1297 (Fed. Cir. 2015)). In this case,
the Board gave the claims their broadest reasonable inter-
pretation. J.A. 84; see Skky, Inc., 859 F.3d at 1019.
     First, Mayne argues that the Board construed the term
“pharmaceutical composition” too broadly to encompass
toxic compositions that do not have any demonstrated ben-
eficial therapeutic properties. Mayne suggests that the
Board should have adopted the construction adopted by the
District of Delaware in companion litigation, which limited
the claim scope to compositions suitable for pharmaceuti-
cal use, Appellant’s Br. 42 (citing J.A. 5307, 5323), thus
avoiding the cited references.
    MSD responds that the specification expressly dis-
closes saperconazole as a “pharmaceutical composition,”
MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.       15



but that extrinsic evidence indicates that saperconazole is
toxic. Thus, in its view, the claims are not limited to non-
toxic compounds.
     We agree with MSD and the Board that the term “phar-
maceutical composition” is not limited to nontoxic composi-
tions. The specification states that the “[t]he term ‘drug’
will be widely understood and denotes a compound having
beneficial prophylactic and/or therapeutic properties when
administered to, for example, humans.” ’745 patent col. 3
ll. 20–22. The specification further comments on “azole an-
tifungal drugs,” stating that “the specific benefits of the
pharmaceutical composition . . . have been established by
the inventors for azole antifungal drugs, such as itracona-
zole and saperconazole.” Id. col. 4 l. 66–col. 5 l. 2. This
language indicates that the claimed “pharmaceutical com-
position” of the claimed drug has at least some beneficial
therapeutic properties, but the specification does not com-
ment on any adverse effects or toxicity. That is not surpris-
ing, as few pharmaceuticals are free of toxic effects in some
circumstances and dosages. Because the specification is si-
lent as to whether the claimed pharmaceutical composition
is limited to being nontoxic, there is no basis to import such
a limitation into the claim.
    Extrinsic evidence also supports the Board’s construc-
tion. The Board credited Graybill, 6 which discloses that
saperconazole, an antifungal disclosed in the patent, was
toxic. J.A. 101–02; J.A. 4815 (“Saperconazole is an ana-
logue of itraconazole that appeared promising during early
clinical development . . . [but] was [] withdrawn from clini-
cal trials because tumors appeared in laboratory animals
that received it.”). Substantial evidence supports the
Board’s findings based on this extrinsic evidence, which


    6   John R. Graybill, The Future of Antifungal Ther-
apy, 22 Supp. 2 CLINICAL INFECTIOUS DISEASES S166 (1996);
J.A. 4813–25.
16   MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




further supports its construction that freedom from toxicity
is not part of the claims.
    Mayne next argues that the Board erred in failing to
limit the claimed pharmacokinetic parameters to humans.
In support of its position, Mayne cites the district court’s
conclusion that “a person of ordinary skill ‘would immedi-
ately understand’ – given the results reported from admin-
istration of an about 100 mg dose – ‘that the claims of the
’745 patent are directed to humans only.’” Appellant’s Br.
46 (quoting J.A. 5321). Mayne also notes that the specifi-
cation includes only human pharmacokinetic data.
     Mayne contests the Board’s reliance on the specifica-
tion’s statement that “[t]he term ‘in vivo’ in general means
in the living body of a plant or animal, whereas the term
‘in vitro’ generally means outside the body and in an artifi-
cial environment.” Id. at 48 (citing ’745 patent col. 3 ll. 36–
38). Specifically, Mayne suggests that the Board erred by
reading this language as lexicography for the term “in vivo”
because CMAX and AUC are metrics irrelevant to plants.
Further, Mayne submits that, if the parameters are ap-
plied to all animals, the pharmacokinetic thresholds would
not exclude any composition from the claims because the
thresholds would be met in animals with significantly
smaller volumes of blood than humans.
     MSD responds that the broadest reasonable interpre-
tation of the claims does not limit them to humans. Specif-
ically, MSD notes that the specification expressly defines
in vivo as “in the living body of a plant or animal.” ’745
patent col. 3 ll. 37. MSD further argues that the pharma-
cokinetic parameters themselves, not the term “in vivo,”
exclude plants from the claim scope. MSD identifies a ref-
erence in the specification to an in vitro pH range of 4.0 to
8.0.
    We agree with MSD that the broadest reasonable in-
terpretation of the claims is not limited to humans. “We
have recognized that ‘the specification may reveal a special
MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.         17



definition given to a claim term by the patentee that differs
from the meaning it would otherwise possess.’” AIA Eng’g
Ltd. v. Magotteaux Int’l S/A, 657 F.3d 1264, 1276 (Fed. Cir.
2011) (quoting Phillips v. AWH Corp., 415 F.3d 1303, 1316
(Fed. Cir. 2005) (en banc)). All of the pharmacokinetic pro-
file “wherein” clauses require that the parameters be met
“in vivo.” The patentees specifically define that term in the
specification: “The term ‘in vivo’ in general means in the
living body of a plant or animal . . . .” ’745 patent col. 3 ll.
36–37. While it is clear that plants are immaterial to the
meaning of the claim because the pharmacokinetic param-
eters are inapplicable to them, and the term pharmaceuti-
cal compositions does not generally mean plant treatments,
animals are expressly recited by the definition of in vivo.
In light of this statement in the specification, a person of
skill would understand the claims to include animals.
    Mayne argues that, because the embodiment in the
specification is from a human trial, the claims should be
limited to humans. But it is improper to import a limita-
tion from an embodiment into the claim. And here, with
clear explanation of the meaning of the term in vivo in the
patent, doing so would be in direct conflict with the speci-
fication. Finally, we are not persuaded that the Board
erred in discounting the district court’s construction be-
cause the court construed the claims under the narrower,
Phillips standard. Power Integrations, Inc. v. Lee, 797 F.3d
1318, 1326 (Fed. Cir. 2015) (“There is no dispute that the
board is not generally bound by a prior judicial construc-
tion of a claim term.”).
     We have considered Mayne’s remaining arguments and
find them unpersuasive. Accordingly, we conclude that the
Board did not err in its constructions of either “pharmaceu-
tical composition” or the “wherein” clauses. Mayne does
not dispute that under the Board’s constructions, Kai an-
ticipates claims 2, 6, 9, 11, 12, and 14, and its combination
with Sangekar and Babcock renders claims 2, 6, and 9–14
obvious. Because we have affirmed the Board’s claim
18   MAYNE PHARMA INT’L PTY. v. MERCK SHARP & DOHME CORP.




constructions, we need not reach Mayne’s remaining argu-
ments on the merits.
                       CONCLUSION
   Because the Board did not err in permitting MSD to
amend its petition to include MCI as a real party in interest
and did not err in construing the claims and then finding
them unpatentable, we affirm the decision of the Board.
                       AFFIRMED
