       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

  PURDUE PHARMA L.P., P.F. LABORATORIES,
    INC., PURDUE PHARMACEUTICALS L.P.,
                  Appellants

                           v.

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

                 2018-1710, 2018-1711
                ______________________

    Appeals from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in Nos. IPR2016-
01412, IPR2016-01413.
                 ______________________

                Decided: April 17, 2019
                ______________________

   JENNIFER LORAINE SWIZE, Jones Day, Washington, DC,
argued for appellants. Also represented by GREGORY A.
CASTANIAS, ROBERT STANDER; GASPER LAROSA, JOHN
JOSEPH NORMILE, JR., New York, NY.

   MARY L. KELLY, Office of the Solicitor, United States
2                                PURDUE PHARMA L.P. v. IANCU




Patent and Trademark Office, Alexandria, VA, argued for
intervenor. Also represented by THOMAS W. KRAUSE,
SARAH E. CRAVEN, JOSEPH MATAL.
               ______________________
      Before DYK, MAYER, and BRYSON, Circuit Judges.
BRYSON, Circuit Judge.
    Purdue Pharma L.P., P.F. Laboratories, Inc., and Pur-
due Pharmaceuticals L.P. (collectively, “Purdue”) appeal
from the decisions of the United States Patent and Trade-
mark Office (“PTO”) Patent Trial and Appeal Board in inter
partes review Nos. IPR2016-01412 and IPR2016-01413.
The Board found claims 1–13 and 16–19 of U.S. Patent No.
9,034,376 (“the ’376 patent”) unpatentable as obvious on
three grounds. Because the Board’s conclusions are sup-
ported by substantial evidence, we affirm.
                             I
    The ’376 patent, entitled “Pharmaceutical Formulation
Containing Gelling Agent,” is directed to abuse-deterrent,
extended release formulations of oxycodone, an analgesic.
The patent issued on May 19, 2015, and is a continuation
of application No. 10/214,412, which was filed on August 6,
2002. The related provisional application No. 60/310,534
(“the ’534 application”), was filed on August 6, 2001.
    The ’376 patent contemplates using two gelling agents,
polyethylene oxide (“PEO”) and hydroxypropylmethylcellu-
lose (“HPMC”) in an oxycodone formulation. When the ox-
ycodone formulation is exposed to an aqueous liquid, those
gelling agents impart a viscosity to the formulation that
makes it unsuitable for parenteral and nasal administra-
tion.
    Claims 1, 18, and 19 of the ’376 patent are independent
claims, and the remainder of the claims are dependent
claims. Claim 1 provides as follows:
PURDUE PHARMA L.P. v. IANCU                               3



     1. A controlled release oral solid dosage form com-
   prising:
    a controlled release matrix comprising a mixture of (i)
       from 2.5 mg to 320 mg oxycodone or a pharmaceuti-
       cally acceptable salt thereof; and
    (ii) a gelling agent comprising [PEO] and [HPMC], the
       gelling agent in an effective amount to impart a vis-
       cosity of at least 10 cP when the dosage form is sub-
       jected to tampering by dissolution in from 0.5 to 10
       ml of an aqueous liquid;
    the controlled release matrix providing a therapeutic
       effect for at least 12 hours when orally administered
       to a human patient.
    Claims 18 and 19 are similar to claim 1, except that
both place functional, rather than numerical, limitations
on the amount of the gelling agent needed to provide deter-
rence. Claim 18 requires the gelling agent in an effective
amount to impart a viscosity “unsuitable for parenteral ad-
ministration,” and claim 19 requires the gelling agent to be
in an amount effective to impart a viscosity “unsuitable to
pull into an insulin syringe.” ’376 patent, claims 18–19.
     Amneal Pharmaceuticals LLC (“Amneal”) filed two pe-
titions for inter partes review of claims 1–13 and 16–19 of
the ’376 patent. In the first petition, Amneal argued that
claims 1–13 and 16–19 were unpatentable for obviousness
on two grounds: (1) the combination of WO 99/32120 (“Pa-
lermo”), Pub. No. US 2002/0187192 A1 (“Joshi”), and the
Handbook of Pharmaceutical Excipients by Kibbe (3d ed.
2000) (“the Handbook”); and (2) the combination of U.S. Pa-
tent No. 5,508,042 (“Oshlack”), Joshi, the Handbook, and
U.S. Patent No. 5,283,065 (“Doyon”). In the second peti-
tion, Amneal argued that claims 1–13 and 16–19 were un-
patentable as obvious on a third ground: the combination
of U.S. Patent No. 5,273,758 (“Royce”), WO 97/49384
(“McGinity”), U.S. Patent No. 4,070,494 (“Hoffmeister”),
Joshi, and the entry for OxyContin in the 1999 edition of
4                                PURDUE PHARMA L.P. v. IANCU




the Physician’s Desk Reference (“PDR”).           The Board
granted the petitions on all three grounds.
    Prior to reaching the merits in both proceedings, the
Board addressed Joshi’s status as prior art. Joshi was pub-
lished on December 12, 2002, based on an application filed
on August 30, 2001; it claims priority to a provisional ap-
plication filed on April 30, 2001. In the petitions for inter
partes review, Amneal asserted that Joshi qualifies as prior
art under 35 U.S.C. § 102(e). Purdue responded that Joshi
does not qualify as 102(e) prior art for two reasons: (1) the
’376 patent is entitled to an earlier filing date based on the
’534 application, filed on August 6, 2001, whereas Joshi is
not entitled to its provisional filing date of April 30, 2001,
and (2) even if Joshi is entitled to priority based on its pro-
visional filing date of April 30, 2001, the ’376 patent has an
earlier invention date.
    Amneal contended that Purdue was collaterally es-
topped from relitigating Joshi’s availability as prior art
based on the final judgment in a district court case regard-
ing U.S. Patent No. 8,337,888 (“the ’888 patent”), which de-
rived from the same provisional application as the ’376
patent. In that litigation, the court relied on Joshi to in-
validate claims of the ’888 patent. In addition, Amneal as-
serted that Purdue failed to carry its burden of establishing
earlier conception and diligence in reducing the claimed in-
vention to practice prior to Joshi’s priority date.
     The Board held that Purdue was collaterally estopped
from challenging Joshi’s status as prior art. The Board rec-
ognized that Purdue has never previously argued that
Joshi did not qualify as prior art. However, the Board con-
cluded that collateral estoppel “applies to ‘issues that were
or could have been raised,’” J.A. 18, 61, and that Purdue
could have challenged Joshi’s status as prior art in the dis-
trict court proceeding regarding the ’888 patent, but did
not.
PURDUE PHARMA L.P. v. IANCU                                  5



     The Board further held that, even if collateral estoppel
did not apply to the issue of Joshi’s priority, Joshi qualifies
as prior art under section 102(e) because Purdue failed to
satisfy its burden of production to show that the ’376 patent
is entitled to a filing date earlier than August 6, 2002. The
Board explained that the claims of the ’376 patent do not
have written description support in either the ’534 provi-
sional or a draft of the patent application dated April 25,
2001. According to the Board, both the ’534 provisional and
the draft application merely include “laundry list” disclo-
sures of possible gelling agents, in which “[HPMC] . . .
[PEO] . . . and mixtures thereof” are among a large number
of other possible gelling agents. Id. at 21, 64. Neither doc-
ument “specifically named or mentioned the combination
in any manner.” Id. at 22, 65. Additionally, the Board
found that “the inventors of the ’376 patent had not con-
ceived of or reduced to practice the claimed formulation
prior to Joshi’s August 30, 2001 filing date.” Id.
     The Board also addressed whether Joshi was entitled
to the earlier filing date of its provisional application. The
Board concluded that Amneal had failed to show “that
Joshi is entitled to an earlier filing date by comparing the
claims of Joshi to the ’509 provisional.” Id. at 19 n.9, 62
n.8. Yet even without the benefit of the filing date of Joshi’s
provisional application, the Board found that the August
30, 2001, filing date of Joshi’s non-provisional application
still pre-dated the ’376 patent’s August 6, 2002, priority
date.
    On the merits, the Board found Purdue’s arguments—
inter alia, that the prior art merely discussed PEO and
HPMC in laundry list disclosures, and that drug release
from HPMC matrix formulations was dependent on tem-
perature, pH, and the active pharmaceutical ingredient—
to be unavailing. According to the Board, the prior art
taught that HPMC, PEO, and a combination of the two may
be used as gelling agents to deter drug abuse, and an expe-
rienced formulator would have “taken into account the
6                                 PURDUE PHARMA L.P. v. IANCU




factors that could affect drug release from a matrix when
formulating an abuse-deterrent, extended release dosage
form for oxycodone.” Id. at 28–29, 75. The Board therefore
held that the ’376 patent is unpatentable for obviousness
on all three instituted grounds.
                             II
     On appeal, Purdue challenges the Board’s conclusion
that Joshi qualifies as prior art (though not arguing prior
inventorship). Purdue contends that the Board improperly
invoked collateral estoppel, and that the claims of the ’376
patent have written description support in the ’534 provi-
sional application. Purdue also challenges the Board’s con-
clusion that claims 1–13 and 16–19 of the ’376 patent are
unpatentable as obvious. It argues that a person of ordi-
nary skill would have lacked motivation to combine HPMC
and PEO in an abuse-deterrent, extended release oxyco-
done formulation, and would have lacked a reasonable ex-
pectation of success in doing so. Amneal did not appear in
this court, so the Director of the PTO intervened to defend
the Board’s decision. The Director supports the Board’s
rulings on all issues but one: the Director submits that the
Board relied on an incorrect reading of Dynamic Drink-
ware, LLC v. National Graphics, Inc., 800 F.3d 1375 (Fed.
Cir. 2015), to hold that Joshi was not entitled to an earlier
filing date. In the Director’s view, however, that issue does
not affect the Board’s ultimate conclusion.
                             A
    Purdue challenges the Board’s invocation of collateral
estoppel on two grounds: that the issue of Joshi’s priority
was not actually litigated in the district court case involv-
ing the ’888 patent, and that the priority issues regarding
the ’888 patent are not identical to the priority issues for
the ’376 patent. We agree with Purdue that the issue of
Joshi’s priority was not actually litigated in the district
court case involving the ’888 patent, and therefore do not
PURDUE PHARMA L.P. v. IANCU                                    7



address whether the priority issues regarding the ’888 pa-
tent are identical to the priority issues for the ’376 patent.
    The Restatement (Second) of Judgments (1982) has
guided this Court’s application of the principles of collat-
eral estoppel. See Voter Verified, Inc. v. Election Sys. &
Software LLC, 887 F.3d 1376, 1383 (Fed. Cir. 2018); Jack-
son Jordan, Inc. v. Plasser Am. Corp., 747 F.2d 1567, 1575–
76 (Fed. Cir. 1984) (citing cases); see also Arizona v. Cali-
fornia, 530 U.S. 392, 414 (2000). Regarding the determi-
nation of whether an issue is actually litigated, comment e
of section 27 of the Restatement states that “[a] judgment
is not conclusive in a subsequent action as to issues which
might have been but were not litigated and determined in
the prior action.” See Voter Verified, 887 F.3d at 1383. The
Restatement further explains that
    [a]n issue is not actually litigated if the defendant
    might have interposed it as an affirmative defense
    but failed to do so . . . if it is raised by a material
    allegation of a party’s pleading but is admitted (ex-
    plicitly or by virtue of a failure to deny) in a respon-
    sive pleading . . . if it is a stipulation between the
    parties. . . . In the case of a judgment entered by
    confession, consent, or default, none of the issues is
    actually litigated.
Restatement (Second) of Judgments § 27, cmt. e.
    The issue of Joshi’s priority was not actually litigated
in the district court proceeding. The district court stated
that “the parties did not stipulate that the Joshi publica-
tion qualifies as prior art to the ’888 patent.” In re: Oxy-
Contin Antitrust Litig., No. 04-MD-1603 (SHS), 2015 WL
11217239, at *24 n.11 (S.D.N.Y. Apr. 8, 2015). And the
Board acknowledged that Purdue “has never previously ar-
gued that Joshi did not qualify as prior art.” J.A. 18, 60.
The requirement that the issue be actually litigated was
therefore not met.
8                                PURDUE PHARMA L.P. v. IANCU




    The Board based its collateral estoppel ruling on the
notion that “collateral estoppel applies to ‘issues that were
or could have been raised’ in the prior litigation.” That
statement, however, conflates the principles of collateral
estoppel and res judicata. See Allen v. McCurry, 449 U.S.
90, 94 (1980) (“Under res judicata, a final judgment on the
merits of an action precludes the parties or their privies
from relitigating issues that were or could have been raised
in that action. Under collateral estoppel, once a court has
decided an issue of fact or law necessary to its judgment,
that decision may preclude relitigation of the issue in a suit
on a different cause of action involving a party to the first
case.”).
    The Director makes several arguments in support of
the Board’s collateral estoppel ruling. First, according to
the Director, Purdue did not distinguish between the Joshi
provisional and non-provisional applications in its appeal
from the district court to the Federal Circuit. Based on
that fact, the Director contends that Purdue implicitly ad-
mitted that the disclosures in Joshi and its provisional ap-
plication are interchangeable, and that Joshi is entitled to
the benefit of the provisional application’s priority date.
    The Director also argues that Purdue responded to Am-
neal’s obviousness challenge by submitting evidence and
argument about the relevant teachings of Joshi and its pro-
visional application. Therefore, the Director argues, “[t]he
fact that Purdue did not directly challenge the sub-issue of
Joshi’s entitlement to its provisional’s filing date does not
mean that the issue was not actually litigated – it was an
essential part of Amneal’s case.” Director’s Br. 32.
     The Director’s arguments are unavailing. There is no
support for the proposition that failing to distinguish be-
tween a provisional and non-provisional application, with-
out more, indicates that Joshi’s priority date was actually
litigated. Nor does the fact that Joshi’s priority date might
have been a potentially important question in the earlier
PURDUE PHARMA L.P. v. IANCU                                    9



litigation mean that it was actually litigated. The priority
date for the Joshi reference therefore cannot be determined
based on collateral estoppel.
                               B
    In light of our disposition of the collateral estoppel is-
sue, it is important to determine whether the ’376 patent
is entitled to priority to the filing date of its provisional ap-
plication. “For a patent to claim priority from the filing
date of its provisional application, it must satisfy 35 U.S.C.
§ 119(e)(1) (2006).” Dynamic Drinkware, 800 F.3d at 1378.
Accordingly, we have made clear that under section
119(e)(1),
    the specification of the provisional must ‘contain a
    written description of the invention and the man-
    ner and process of making and using it, in such full,
    clear, concise, and exact terms,’ 35 U.S.C. § 112 ¶
    1, to enable an ordinarily skilled artisan to practice
    the invention claimed in the non-provisional appli-
    cation.
New Railhead Mfg., L.L.C. v. Vermeer Mfg. Co., 298 F.3d
1290, 1294 (Fed. Cir. 2002); see Dynamic Drinkware, 800
F.3d at 1378.
    Purdue argues that the ’534 provisional application
satisfies the written description requirement as to the ’376
claims. It points to the following disclosure in the ’534 pro-
visional as supporting the claimed dosage forms:
    In certain embodiments of the present invention
    wherein the dosage form includes an aversive
    agent comprising a gelling agent, various gelling
    agents can be employed including, for example and
    without limitation, sugars or sugar derived alco-
    hols, such as mannitol, sorbitol, and the like, starch
    and starch derivatives, cellulose derivatives, such
    as microcrystalline cellulose, sodium carboxyme-
    thyl cellulose, methylcellulose, ethyl cellulose,
10                               PURDUE PHARMA L.P. v. IANCU




     hydroxyethyl cellulose, hydroxypropyl cellulose,
     and [HPMC], attapulgites, bentonites, dextrins, al-
     ginates, carrageenan, gum tragacanth, gum acacia,
     guar gum, xanthan gum, pectin, gelatin, kaolin,
     lecithin, magnesium aluminum silicate, the car-
     bomers and carbopols, polyvinylpyrrolidone, poly-
     ethylene glycol, [PEO], polyvinyl alcohol, silicon
     dioxide, surfactants, mixed surfactant/wetting
     agent systems, emulsifiers, other polymeric mate-
     rials, and mixtures thereof, etc. In certain pre-
     ferred embodiments, the gelling agent is xanthan
     gum. In other preferred embodiments, the gelling
     agent of the present invention is pectin.
’534 application, at 10. Purdue’s expert, Dr. Stephen Byrn,
relied on that disclosure to conclude that the ’534 specifica-
tion discloses the HPMC and PEO gelling agent claim ele-
ment of the ’376 patent. Purdue contends that Dr. Byrn’s
testimony was entirely unrebutted by Amneal. In addition,
Purdue highlights other portions of the ’534 application
that discuss HPMC and PEO as components in preferred
embodiments of the invention, though never in combina-
tion.
    The Director argues that the disclosure from the ’534
application quoted above does not reasonably convey to an
ordinary artisan that the inventor had possession of oxyco-
done dosage forms containing mixtures of PEO and HPMC.
Additionally, the Director argues that Purdue never cited
the other portions of the ’534 application disclosures to the
Board, and thus waived reliance on them.
    This Court has recognized that “simply describing a
large genus of compounds is not sufficient to satisfy the
written description requirement as to particular species or
sub-genuses.” Fujikawa v. Wattanasin, 93 F.3d 1559, 1571
(Fed. Cir. 1996); see In re Ruschig, 379 F.2d 990, 994–95
(CCPA 1967). In the ’534 application disclosure, PEO and
HPMC are merely two of many undifferentiated
PURDUE PHARMA L.P. v. IANCU                                 11



compounds that fall within the genus of gelling agents.
Such “laundry list” disclosures do not provide adequate
specificity to constitute written description support for
Purdue’s claim of priority. To be sure, the language “mix-
tures thereof” suggests the possibility of combining two or
more of the listed gelling agents. Without more, however,
that language fails to highlight any preference for how
many and which gelling agents to combine.
     The expert testimony on which Purdue relies does not
compel a different conclusion. Purdue’s expert, Dr. Byrn,
failed to identify any rationale to distinguish PEO and
HPMC from the other listed gelling agents. Instead, Dr.
Byrn merely stated that “each element of the inventions in
claims 1–13 and 16–19 of the ’376 patent can be found in
the ’534 provisional application,” and cited the laundry list
disclosure quoted above. J.A. 2907–09. That undeveloped,
conclusory evidence does not undermine the Board’s find-
ing on this issue. See SkinMedica, Inc. v. Histogen Inc., 727
F.3d 1187, 1210 (Fed. Cir. 2013).
     As for Purdue’s argument that Amneal’s expert failed
to rebut Dr. Byrn’s testimony, Purdue never met its burden
to show that the ’376 patent is entitled to claim the benefit
of the ’534 application’s filing date. It was therefore not
necessary for Amneal to offer expert evidence to the con-
trary. See Dynamic Drinkware, 800 F.3d at 1379 (stating
that once the petitioner meets its initial burden of going
forward with evidence that there is anticipating prior art,
the patent owner has “the burden of going forward with ev-
idence either that the prior art does not actually anticipate,
or . . . that it is not prior art because the asserted claim is
entitled to the benefit of a filing date prior to the alleged
prior art.” (quoting Tech. Licensing Corp. v. Videotek, Inc.,
545 F.3d 1316, 1327 (Fed. Cir. 2008))).
    Purdue argues that the declaration of Amneal’s expert,
Dr. Robert J. Timko, affirmatively supports Purdue’s posi-
tion on priority. Dr. Timko acknowledged that the ’376
12                                PURDUE PHARMA L.P. v. IANCU




patent “claims priority to its own provisional application
filed on August 6, 2001.” J.A. 4332. Purdue characterizes
that statement as an acknowledgment that the ’376 patent
has written description support in the ’534 provisional. We
disagree. Dr. Timko’s statement that the patent “claims
priority” to its provisional application merely acknowl-
edges that the patent asserts priority as of that date; it does
not constitute an agreement or concession that the claimed
priority date is accurate.
     Finally, we agree with the Director that Purdue waived
its arguments relying on the additional disclosures of the
’534 application. See In re Baxter Int’l, Inc., 678 F.3d 1357,
1362 (Fed. Cir. 2012) (“Absent exceptional circumstances,
we generally do not consider arguments that the applicant
failed to present to the Board.”). Even if Purdue’s argu-
ments were considered, they would not change the result.
The additional references to PEO and HPMC throughout
the provisional application do not constitute “blaze marks”
that indicate or direct that a particular combination should
be made “rather than any of the many others which could
also be made.” In re Ruschig, 379 F.2d at 995.
    Accordingly, the court finds that substantial evidence
supports the Board’s conclusion that the claims of the ’376
patent do not have written description support in the ’534
provisional application.
                              C
    On appeal, Purdue’s argument that Joshi does not
qualify as prior art is based entirely on its contention that
the claims of the ’376 patent have written description sup-
port in the ’534 provisional. Purdue does not challenge the
Board’s findings that claims of the ’376 patent are not sup-
ported by the draft of the patent application dated April 25,
2001, or that the inventors of the ’376 patent did not con-
ceive of or reduce to practice the claimed formulation prior
to Joshi’s August 30, 2001, filing date. Therefore, given our
conclusion that the claims of the ’376 patent do not have
PURDUE PHARMA L.P. v. IANCU                               13



written description support in the ’534 provisional, we hold
that Joshi qualifies as prior art and that the Board permis-
sibly relied on Joshi in all three grounds of the Board’s ob-
viousness analysis. 1
                              III
    As stated above, the Board found claims 1–13 and 16–
19 of the ’376 patent unpatentable as obvious on three
grounds. We focus on ground 3, and conclude that the
Board’s finding that the ’376 patent would have been obvi-
ous over Royce, McGinity, Hoffmeister, Joshi, and the PDR
is supported by substantial evidence.
    As the Board explained, Royce teaches a sustained re-
lease formulation that includes both PEO and HPMC.
Royce also suggests that sustained release dosage formula-
tions may be used for analgesics, a category of drug that
includes oxycodone. McGinity teaches controlled release
dosage forms of analgesics. Hoffmeister and Joshi teach
that HPMC and PEO are gelling agents that may be used
in an abuse-deterrent formulation. And the PDR teaches
extended release oxycodone formulations in doses of 10 mg,
20 mg, 40 mg, and 80 mg. Purdue makes a series of argu-
ments challenging the Board’s obviousness determination.
The Court finds each argument unconvincing.
    First, Purdue challenges the Board’s finding of a moti-
vation to combine the cited references. Purdue argues that
the Board impermissibly cherry-picked PEO and HPMC
from lists of ingredients in prior art. Example 2 in Royce,
however, expressly discloses sustained release dosage
forms comprising PEO and HPMC. Example 2’s disclosure
of a combination of PEO and HPMC as gelling agents


    1    Our decision on this issue renders moot the Direc-
tor’s contention that the Board relied on an incorrect read-
ing of Dynamic Drinkware to conclude that Joshi was not
entitled to an earlier filing date.
14                             PURDUE PHARMA L.P. v. IANCU




contradicts Purdue’s argument that Royce emphasizes sus-
tained release dosage forms using PEO only, and that
Royce merely discusses HPMC as an optional component:
HMPC is not an optional component in the example 2 for-
mulation. Purdue points out that example 2 of Royce was
for a placebo, and that the only example in Royce that
shows an extended release profile for a drug product uses
PEO alone. While that is true, nothing in Royce suggests
that PEO-based tablets, as compared to tablets containing
PEO and HPMC, are preferred in sustained release dosage
formulations.
    Second, Purdue argues that the Board asked whether
an artisan could have combined HPMC and PEO, rather
than whether an artisan would have done so. According to
Purdue, “[b]y choosing HPMC or PEO from laundry lists of
possibly ingredients, without direction from the reference
themselves . . . the Board improperly focused on what was
possible for an ordinary artisan, and not what an ordinary
artisan would have been motivated to choose.” Appellants’
Br. 47. Because Royce successfully combined HPMC and
PEO, however, that argument fails. Nor do we agree with
Purdue that the Board used the wrong legal standard for
assessing the motivation to combine. Purdue criticizes the
Board for stating that a skilled artisan “would have there-
fore understood that oxycodone hydrochloride could also be
included among the possible drugs in the sustained release
formulation.” J.A. 71. Nothing in that statement, however,
reflects a misunderstanding of the proper standard.
    Third, Purdue argues that the prior art taught away
from using HPMC in an abuse-deterrent, extended release
formulation in three ways. According to Purdue, the prior
art taught that heating an aqueous solution of HPMC de-
creases its viscosity, and that HPMC’s abuse-deterrent gel-
ling effects would be rendered ineffective by a typical
method of drug abuse (i.e., heating the dosage form). Next,
Purdue argues that the prior art taught that HPMC im-
proves the absorption of drugs through the nasal tissue,
PURDUE PHARMA L.P. v. IANCU                               15



and thus would not deter nasal abuse. Last, Purdue char-
acterizes the prior art as suggesting that HPMC would not
reliably release oxycodone over an extended period of time.
    As the Board found, Dr. Timko offered undisputed tes-
timony that refutes Purdue’s teaching away arguments. 2
See id. at 75. Dr. Timko stated that “[t]he references Pur-
due cites are publications teaching that HPMC was, in fact,
a well-known gelling agent for use in a matrix dosage form
and any potential interactions could be easily addressed.”
Id. at 4343. According to Dr. Timko, “[a]n experienced for-
mulator, at the time of the invention, would be aware of all
of these things and would formulate their dosage form ac-
cordingly.” Id.
    Fourth, Purdue argues that the science of abuse-deter-
rent extended release oxycodone formulations was so un-
predictable that there was no expectation of success for the
claimed dosage forms. According to Purdue: (1) the gelling
agents were generally unpredictable in extended release
pharmaceutical formulations, (2) none of the prior art


    2   Purdue argues that Dr. Timko’s testimony was not
undisputed. According to Purdue, the Board ignored Dr.
Byrn’s declaration, which allegedly contradicted Dr.
Timko’s conclusions. We disagree. The Board directly ad-
dressed Dr. Byrn’s declaration, finding that the “prior art
references relied on by . . . Dr. Byrn merely discuss how the
viscosity, gelling, and drug release properties of HPMC-
based formulations may be affected by temperature and
other external factors.” J.A. 75. Those observations, ac-
cording to the Board, failed to “suggest that HPMC should
not be used in a drug formulation for those reasons.” Id.
Dr. Byrn did not contradict Dr. Timko’s testimony that an
experienced formulator could easily address the effects of
external factors on the HPMC-based formulation. See id.
at 2929–30. Thus, we conclude that Dr. Timko’s testimony
on that point was undisputed.
16                                PURDUE PHARMA L.P. v. IANCU




contained relevant data on the rate of drug release from
HPMC-PEO formulations, and (3) the Bastin prior art ref-
erence (WO 95/20947) reinforced the understanding that
gelling agents would lead to unpredictable rates of drug re-
lease.
   All three of those arguments fail. As to the first argu-
ment, Royce demonstrated the success of a mixture of PEO
and HPMC in controlled-release oral dosage forms.
     As to the second argument, the challenged claims of the
’376 patent do not require any particular dissolution profile
or release rate for the drug. Therefore, while the prior art
does not contain data on the rate of drug release from the
HPMC-PEO formulations, the Court finds it sufficient that
the prior art suggests a reasonable probability of success
based on controlled release formulations using PEO. See
Pfizer, Inc. v. Apotex, Inc., 480 F.3d 1348, 1364 (Fed. Cir.
2007) (“[The] case law is clear that obviousness cannot be
avoided simply by a showing of some degree of unpredicta-
bility in the art so long as there was a reasonably probabil-
ity of success.”); see also J.A. 838 (Royce depicts a controlled
release profile of clemastine fumarate using PEO, over a
period of 18 hours).
    As to the third argument, the Bastin prior art reference
merely suggests that gelling agents would pose a problem
for immediate release formulations. See J.A. 545 (“[T]he
gelling agent in a single layer with the drug substance
causes a serious retardation of release”). It does not, how-
ever, suggest that gelling agents were unpredictable for
sustained release formulations. See In re: OxyContin Anti-
trust Litig., 2015 WL 11217239, at *26 (“Placed in its
proper context, Bastin provides very little support to Pur-
due. Bastin expressed concern about gelling agents’ effect
on drug release only with respect to immediate release for-
mulations, for which delay poses a serious problem. By
drawing an explicit comparison between gelling agents and
the swelling properties of rate controlling high molecular
PURDUE PHARMA L.P. v. IANCU                              17



weight polymers, Bastin in fact implies that gelling agents
are well-suited to controlled release dosage forms.”). The
Board’s finding that the prior art provided a reasonable ex-
pectation of success is thus supported by substantial evi-
dence.
                              IV
    We affirm the Board’s determination that claims 1–13
and 16–19 of the ’376 patent are unpatentable for obvious-
ness.
   Each party shall bear its own costs for these appeals.
                       AFFIRMED
