Grunenthal Gmbh v. Alkem Laboratories Limited , 919 F.3d 1333 ( 2019 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    GRUNENTHAL GMBH, ASSERTIO
    THERAPEUTICS, INC.,
    Plaintiffs-Cross-Appellants
    v.
    ALKEM LABORATORIES LIMITED, HIKMA
    PHARMACEUTICALS INTERNATIONAL LIMITED,
    HIKMA PHARMACEUTICALS USA INC.,
    Defendants-Appellants
    ACTAVIS ELIZABETH LLC,
    Defendant-Appellee
    ACTAVIS LABORATORIES UT, INC.,
    Defendant
    ______________________
    2017-1153, 2017-2048, 2017-2049, 2017-2050
    ______________________
    Appeals from the United States District Court for the
    District of New Jersey in Nos. 2:13-cv-04507-CCC-MF,
    2:13-cv-06929-CCC-MF, 2:13-cv-07803-CCC-MF, 2:14-cv-
    03941-CCC-MF, 2:14-cv-04617-CCC-MF, 2:15-cv-06797-
    CCC-MF, Judge Claire C. Cecchi.
    ______________________
    Decided: March 28, 2019
    ______________________
    2         GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    MICHAEL SITZMAN, Gibson, Dunn & Crutcher LLP, San
    Francisco, CA, argued for all plaintiffs-cross-appellants.
    Plaintiff-cross-appellant Assertio Therapeutics, Inc. also
    represented by JAYSEN CHUNG; CHRISTINE RANNEY, Den-
    ver, CO; TIMOTHY P. BEST, Los Angeles, CA.
    LINDA A. WADLER, Finnegan, Henderson, Farabow,
    Garrett & Dunner, LLP, Washington, DC, for plaintiff-
    cross-appellant Grunenthal GmbH. Also represented by
    KRISTA E. BIANCO.
    MICHAEL E. JOFFRE, Sterne Kessler Goldstein & Fox,
    PLLC, Washington, DC, argued for defendant-appellee.
    Also represented by WILLIAM H. MILLIKEN.
    ROBERT J. GAJARSA, Latham & Watkins LLP, Washing-
    ton, DC, argued for defendants-appellants Hikma Pharma-
    ceuticals International Limited, Hikma Pharmaceuticals
    USA Inc. Also represented by KENNETH G. SCHULER, Chi-
    cago, IL; GREGORY SOBOLSKI, San Francisco, CA.
    IMRON T. ALY, Schiff Hardin, Chicago, IL, argued for
    defendant-appellant Alkem Laboratories Limited. Also
    represented by CINDY AHN, JASON HARP, NEIL LLOYD;
    AHMED M.T. RIAZ, New York, NY.
    ______________________
    Before REYNA, TARANTO, and CHEN, Circuit Judges.
    REYNA, Circuit Judge.
    Alkem Laboratories Limited, Hikma Pharmaceuticals
    International Limited, and Hikma Pharmaceuticals USA
    Inc. appeal the judgment of the district court that U.S. Pa-
    tent No. 7,994,364 is not invalid for obviousness or lack of
    utility. Grünenthal GmbH and Assertio Therapeutics, Inc.,
    formerly Depomed, Inc., cross-appeal the finding that
    Hikma Pharmaceuticals International Limited, Hikma
    Pharmaceuticals USA Inc., and Actavis Elizabeth LLC do
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED                3
    not infringe 
    U.S. Patent No. 8,536,130
    . Because the dis-
    trict court did not err in its conclusions, we affirm.
    BACKGROUND
    A. Patents at Issue
    Grünenthal GmbH (“Grünenthal”) is the assignee of
    U.S. Patent Nos. 7,994,364 (“the ’364 patent”) and
    8,536,130 (“the ’130 patent”). Assertio Therapeutics, Inc.,
    formerly Depomed, Inc. (“Depomed”), is an exclusive licen-
    see of both patents. Each patent is listed in the U.S. Food
    and Drug Administration’s (“FDA”) Approved Drug Prod-
    ucts with Therapeutic Equivalence Evaluations (the “Or-
    ange Book”) for NUCYNTA® ER (extended release), a
    tapentadol hydrochloride tablet. J.A. 52853, 52856. The
    ’364 patent is directed to the Form A polymorph 1 of the
    chemical compound tapentadol hydrochloride and a
    method of treating pain and/or urinary incontinence. 2 See
    ’364 patent, Abstract; 
    id.
     col. 18 l. 66–col. 19 l. 4. The ’364
    patent states that Form A “is very stable at ambient condi-
    tions and therefore useful for producing a pharmaceutical
    composition.” 
    Id.
     col. 1 ll. 63–67. The asserted claims of
    the ’364 patent, claims 1, 2, 3, and 25, recite various X-ray
    powder diffraction (XRPD) patterns. See, e.g., 
    id.
     col. 18 l.
    65–col. 19 l. 4. XRPD is a method for measuring the X-rays
    scattered by a polycrystalline sample as a function of scat-
    tering angle. Each polymorph has a unique XRPD.
    The ’130 patent describes a method of using tapentadol
    and tapentadol hydrochloride for the treatment of polyneu-
    ropathic pain. Polyneuropathic pain is a type of pain
    1   A polymorph is a chemical compound that can pre-
    sent in different three-dimensional crystalline structures.
    2   The patent claims “(–)-(1R,2R)-3-(3-dimethyla-
    mino-1-ethyl-2-methylpropyl)-phenol         hydrochloride,”
    which is tapentadol hydrochloride. ’364 patent, col. 18 ll.
    66–67; see also Grünenthal Br. 8.
    4          GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    caused by damage to multiple nerves. In contrast, mo-
    noneuropathic pain is pain associated with damage to a
    single nerve.
    Claim 1 of the ’130 patent is directed to the method of
    treating “polyneuropathic pain” with tapentadol or “a phar-
    maceutically acceptable salt thereof,” i.e., tapentadol hy-
    drochloride. ’130 patent, col. 18 ll. 2–7. Claim 2 is directed
    to the method of treating polyneuropathic pain using “a hy-
    drochloric salt” of tapentadol, i.e., tapentadol hydrochlo-
    ride. 
    Id.
     col. 18 ll. 8–10.
    B. Prior Art References
    There are two different polymorphs of tapentadol hy-
    drochloride: Form A and Form B. Form B of tapentadol
    hydrochloride was known in the art and previously dis-
    closed in 
    U.S. Patent No. 6,248,737
     (“the ’737 patent”), also
    assigned to Grünenthal. See ’364 patent, col. 1 ll. 58–63.
    The ’737 patent discloses a number of compounds, includ-
    ing tapentadol hydrochloride, intended to have an analge-
    sic effect suitable for the treatment of pain. See, e.g., ’737
    patent, col. 1 l. 52–col. 2 l. 36; 
    id.,
     Example 25, col. 20 ll. 1–
    20. 3 Specifically, Example 25 of the ’737 patent discloses
    the steps for synthesizing tapentadol hydrochloride. The
    ’737 patent states that tapentadol hydrochloride was crys-
    tallized, but it does not describe the resulting crystal struc-
    ture, nor does it discuss polymorphs.
    Also known in the art at the time of filing was the con-
    cept of polymorph screening, which is the practice of char-
    acterizing all crystal forms of a chemical compound. A
    3   Example 25 incorporates by reference the synthe-
    sis steps of Example 24 and the synthesis preparation pro-
    cess of Example 2 of the ’737 patent. ’737 patent, col. 20 ll.
    18–20.
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED               5
    1995 article by Byrn et al. 4 (“Byrn”) “describes a conceptual
    approach to the characterization of pharmaceutical solids,”
    including a flow chart describing investigative steps to de-
    termine whether polymorphs are possible. J.A. 57372–73.
    Byrn does not outline a particular method to definitively
    test for polymorphism. 5 Instead, it provides a decision tree
    outlining, among other things, different ways to gain addi-
    tional information about whether polymorphs exist for a
    particular chemical compound and lists various analytical
    tests to identify polymorphs. J.A. 57373.
    To determine whether polymorphs are possible, Byrn
    lists a number of solvents to be used in recrystallizing the
    substance in question. The listed solvents are water, meth-
    anol, ethanol, propanol, isopropanol, acetone, acetonitrile,
    ethyl acetate, and hexane. 
    Id.
     Other variables such as
    temperature, concentration, agitation, and pH could affect
    the solids produced by recrystallization with these various
    solvents. 
    Id.,
     Figure 1. This case focuses on the extent and
    limits of what the disclosure in Byrn teaches about discov-
    ering polymorphs, if any, of a known compound, and ulti-
    mately, whether a skilled artisan would reasonably expect
    the recrystallization of tapentadol hydrochloride to result
    in any polymorph, let alone one with the physical proper-
    ties of Form A.
    C. Proceedings in District Court
    Grünenthal and Depomed (collectively, “Cross-Appel-
    lants”) brought suit against Alkem Laboratories Limited
    4    Stephen Byrn et al., Pharmaceutical Solids: A
    Strategic Approach to Regulatory Considerations, 12 Phar-
    maceutical Res. 945 (1995).
    5   Polymorphism is the ability of a compound to crys-
    tallize in more than one crystal arrangement but retain the
    same chemical structure. J.A. 8528 (228:11–14); J.A.
    57373.
    6         GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    (“Alkem”), Hikma Pharmaceuticals International Lim-
    ited, 6 Hikma Pharmaceuticals USA Inc. (collectively,
    “Hikma”), and Actavis Elizabeth LLC (“Actavis”), 7 alleging
    infringement of the ’364 and ’130 patents stemming from
    their respective Abbreviated New Drug Application
    (“ANDA”) filings seeking to market generic versions of im-
    mediate and extended release tapentadol hydrochloride
    tablets. 8 All defendants subsequently stipulated to in-
    fringement of the ’364 patent. Alkem and Hikma chal-
    lenged the validity of the ’364 and ’130 patents.
    After a bench trial, the district court concluded that
    Alkem infringes the ’130 patent, but that Actavis and
    Hikma do not. In re Depomed Patent Litig., No. 13-cv-4507-
    CCC-MF, 
    2016 WL 7163647
    , at *2 (D.N.J. Sept. 30, 2016)
    (“Depomed Litigation”). The district court also determined
    that the ’364 patent is not invalid as obvious, that the ’130
    patent is not invalid as anticipated, and that the ’130
    6    Hikma Pharmaceuticals International Limited
    was formerly known as West-Ward Pharmaceuticals Inter-
    national Limited. During pendency of this appeal, defend-
    ant Roxane Laboratories, Inc. (“Roxane”) transferred
    ownership of its ANDA applications, which are at issue in
    the instant appeal, to West-Ward Pharmaceuticals Inter-
    national Limited. ECF No. 65. As a result, West-Ward
    Pharmaceuticals International Limited was substituted for
    Roxane in this appeal. ECF No. 66.
    7   Grünenthal and Depomed also brought suit
    against Actavis Laboratories UT, Inc., Actavis LLC, and
    Actavis, Inc. These defendants did not participate in this
    appeal.
    8   U.S. Patent Nos. RE39,593 and 8,309,060 were also
    asserted. J.A. 33. U.S. Patent No. RE39,593 is not directly
    at issue in this appeal, but Hikma relies on it for purposes
    of its invalidity arguments. The proceedings involving 
    U.S. Patent No. 8,309,060
     were stayed by the district court. 
    Id.
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED             7
    patent is not invalid due to obviousness-type double pa-
    tenting in light of U.S. Patent No. RE39,593. 
    Id.
    Alkem and Hikma each appeal different aspects of the
    district court’s invalidity rulings.     Grünenthal and
    Depomed collectively appeal the district court’s finding of
    noninfringement of the ’130 patent. We have jurisdiction
    under 
    28 U.S.C. § 1295
    (a)(1).
    DISCUSSION
    Much of Hikma’s argument on appeal is made in the
    alternative and many of its arguments become moot should
    we hold Hikma does not infringe the ’130 patent. There-
    fore, we will first address Cross-Appellants’ arguments re-
    garding noninfringement. We will then address Alkem’s
    appeal of the finding that the ’364 patent is not invalid as
    obvious and Hikma’s challenge to the utility and validity of
    the ’130 patent.
    A. Infringement
    We begin with a discussion of Grünenthal and
    Depomed’s cross-appeal. Because neither Hikma’s nor Ac-
    tavis’s proposed label is indicated to treat polyneuropathic
    pain, and the case made by Grünenthal and Depomed for
    indirect infringement depended on the proposed label indi-
    cations, we agree with the trial court that Hikma and Ac-
    tavis do not induce infringement of or contributorily
    infringe claims 1 and 2 of the ’130 patent.
    Depomed has several NUCYNTA® products used “for
    the management of moderate to severe acute pain in
    adults.” See J.A. 70–73. One of Depomed’s products,
    NUCYNTA® ER (extended release), is a tablet approved for
    the following indications:
    NUCYNTA® ER is an opioid agonist indicated for
    the management of:
    •   moderate to severe chronic pain in adults
    8          GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    •   neuropathic pain associated with diabetic
    peripheral neuropathy (DPN) in adults
    when a continuous, around-the-clock opioid analge-
    sic is needed for an extended period of time.
    J.A. 50091 (emphasis added, reference numerals omitted).
    The label makes no explicit reference to “polyneuropathic
    pain,” but DPN is a type of polyneuropathic pain. Depomed
    Br. 18, 20. The original label for NUCYNTA® ER did not
    include the second indication to treat neuropathic pain.
    J.A. 50310.
    Hikma and Actavis each filed ANDAs seeking approval
    to market a generic version of tapentadol hydrochloride ex-
    tended release tablets. Both parties filed “Section viii”
    statements under 
    21 U.S.C. § 355
    (j)(2)(A)(viii), whereby
    Hikma and Actavis told FDA that they will not seek FDA
    approval for an indication directed to the treatment of
    DPN. J.A. 7290–91; see also J.A. 52858.
    Induced Infringement
    After a bench trial, this court reviews a district court’s
    judgment for legal error or clearly erroneous findings of
    fact. SmithKline Beecham Corp. v. Apotex Corp., 
    403 F.3d 1331
    , 1337 (Fed. Cir. 2005). Infringement is a question of
    fact reviewed for clear error. AstraZeneca LP v. Apotex,
    Inc., 
    633 F.3d 1042
    , 1056 (Fed. Cir. 2010) (quoting Golden
    Blount, Inc. v. Robert H. Peterson Co., 
    438 F.3d 1354
    , 1361
    (Fed. Cir. 2006)) (internal quotation marks omitted); Alcon
    Research Ltd. v. Barr Labs., Inc., 
    745 F.3d 1180
    , 1186 (Fed.
    Cir. 2014). A finding is clearly erroneous when “the review-
    ing court is left with the definite and firm conviction that a
    mistake has been made.” AstraZeneca, 
    633 F.3d at 1056
    .
    In this case, the question of induced infringement turns
    on whether Hikma and Actavis have the specific intent,
    based on the contents of their proposed labels, to encourage
    physicians to use their proposed ANDA products to treat
    polyneuropathic pain. See Takeda Pharm. U.S.A., Inc. v.
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED                 9
    West-Ward Pharm. Corp., 
    785 F.3d 625
    , 631 (Fed. Cir.
    2015). In other words, we ask whether the label encour-
    ages, recommends, or promotes infringement.             
    Id.
    Depomed argues that because the Hikma and Actavis la-
    bels contain an indication for severe chronic pain, the la-
    bels will cause at least some users to infringe the ’130
    patent because polyneuropathic pain is a common form of
    “severe chronic pain.” Depomed Br. 61–62.
    “The pertinent question is whether the proposed label
    instructs users to perform the patented method.” Astra-
    Zeneca, 
    633 F.3d at 1060
    . In this case, we ask whether the
    Hikma and Actavis labels instruct users to treat polyneu-
    ropathic pain with tapentadol hydrochloride. They do not.
    Actavis’s proposed ANDA product is indicated for
    “[p]ain severe enough to require daily, around-the-clock,
    long-term opioid treatment.” J.A. 52679. Hikma’s pro-
    posed ANDA product has a similar indication, designated
    for “[m]oderate to severe chronic pain in adults when a con-
    tinuous, around-the-clock opioid analgesic is needed for an
    extended period of time.” J.A. 56864–65; see also Hikma
    Br. 23. To support these indications, the Hikma and Ac-
    tavis proposed labels cite chronic lower back pain studies,
    a type of pain that both Cross-Appellants and FDA defined
    as nociceptive. 9 At trial, experts on both sides testified that
    severe chronic pain could be neuropathic pain or nocicep-
    tive pain. E.g., J.A. 9190 (169:9–17); J.A. 9388 (40:15–22);
    J.A. 9389 (41:19–23); J.A. 9399 (51:20–22); J.A. 10630
    (54:2–8); J.A. 11161 (12:4–14); J.A. 11208 (59:13–20). In
    other words, even if severe chronic pain includes polyneu-
    ropathic pain, it also includes mononeuropathic pain and
    nociceptive pain. Therefore, the proposed ANDA labels do
    9  Nociceptive pain is pain associated with damage to
    non-neural tissue, or non-nerve tissue.
    10        GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    not specifically encourage use of tapentadol hydrochloride
    for treatment of polyneuropathic pain.
    Further, it is undisputed that neither of the accused
    ANDA labels list an indication for the management of pain
    associated with DPN. Nor do they mention any DPN clin-
    ical studies, which served as the basis for FDA approval of
    NUCYNTA® ER’s indication for the treatment of neuro-
    pathic pain. In fact, both Hikma and Actavis filed “Section
    viii” statements with FDA specifically carving out the neu-
    ropathic pain indication. Accordingly, we agree with the
    district court that these labels do not encourage infringe-
    ment of the ’130 patent. See Takeda, 785 F.3d at 631 (“The
    label must encourage, recommend, or promote infringe-
    ment.”).
    Cross-Appellants rely heavily on the holding in Astra-
    Zeneca LP v. Apotex, Inc., where we held that if the label
    instructs “at least some users” to infringe the patent, then
    specific intent to induce infringement may be inferred. 
    633 F.3d at
    1059–60. But AstraZeneca is inapposite to our
    facts. We held that specific intent could be inferred be-
    cause the defendant proceeded with a plan to distribute the
    generic drug knowing that its label posed infringement
    problems. 
    Id.
     In addition, the instructions in the DOSAGE
    AND ADMINISTRATION section of the label “would inev-
    itably lead some consumers to practice the claimed
    method” of once-daily dosing by encouraging users to taper
    downward to the “lowest effective dose” and showing the
    lowest effective dose to be the lowest available strength,
    administered daily. 
    Id. at 1057
    , 1059–60. Here, Grünen-
    thal and Depomed point only to the indications of the pro-
    posed labels as grounds for inducement, which, as
    explained above, do not implicitly or explicitly encourage
    or instruct users to take action that would inevitably lead
    to use of tapentadol hydrochloride for treatment of poly-
    neuropathic pain. Therefore, we discern no clear error and
    uphold the district court’s finding of no induced infringe-
    ment.
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED               11
    Contributory Infringement
    To establish liability for contributory infringement, a
    patent owner must show, inter alia, that there are no sub-
    stantial noninfringing uses for the accused product.
    
    35 U.S.C. § 271
    (c). A noninfringing use is substantial
    when it is “not unusual, far-fetched, illusory, impractical,
    occasional, aberrant, or experimental.” Toshiba Corp. v.
    Imation Corp., 
    681 F.3d 1358
    , 1362 (Fed. Cir. 2012) (quot-
    ing Vita-Mix Corp. v. Basic Holding, Inc., 
    581 F.3d 1317
    ,
    1327 (Fed. Cir. 2009)). In a pharmaceutical case, the non-
    infringing use must be in accordance with the use for which
    the product is indicated. Eli Lilly and Co. v. Actavis Eliz-
    abeth LLC, 435 F. App’x 917, 927 (Fed. Cir. 2011) (“[U]nau-
    thorized activity does not avoid infringement by a product
    that is authorized to be sold solely for the infringing use.”).
    The question before us is whether the noninfringing
    uses Hikma and Actavis identified for the district court are
    “substantial.” Cross-Appellants argue that any non-in-
    fringing uses for the proposed ANDA products are “rare”
    and not substantial. Depomed Response Br. 74. We disa-
    gree and find no clear error in the district court’s finding
    that Hikma and Actavis do not contributorily infringe the
    ’130 patent.
    The district court weighed the testimony of all experts
    in this case, giving due consideration to both Cross-Appel-
    lants’ and Appellants’ experts. Cross-Appellants’ experts
    opined that most of the uses of the proposed ANDA prod-
    ucts would be directed to chronic, polyneuropathic pain.
    Appellants’ experts, some of whom included practicing phy-
    sicians, provided testimony about the use of tapentadol hy-
    drochloride in their respective practices, including
    statements that they have prescribed opioids to treat se-
    vere chronic pain conditions that are nociceptive or not pol-
    yneuropathic. They testified that treating nociceptive or
    mononeuropathic conditions with tapentadol hydrochlo-
    ride would not be unusual. Although there appears to be
    12        GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    evidence supporting both positions, the court made credi-
    bility determinations that supported Hikma and Actavis’s
    theory of noninfringement. We see no reason to disturb
    those findings. See Nilssen v. Osram Sylvania, Inc., 
    504 F.3d 1223
    , 1231–32 (Fed. Cir. 2007) (“While an opposite
    conclusion could have been reached, it is not the function
    of a court of appeals to override district court judgments on
    close issues, where credibility findings have been made.”);
    Agfa Corp. v. Creo Prods. Inc., 
    451 F.3d 1366
    , 1379 (Fed.
    Cir. 2006) (“This court must defer heavily to the trial
    court’s credibility determinations.”).
    B. Obviousness
    Obviousness is a question of law with underlying fac-
    tual findings related to, among other things, the scope and
    content of the prior art, whether a person of ordinary skill
    in the art (“POSA”) would have had reason to combine or
    modify the prior art to arrive at the claimed invention, and
    in so doing, would have had a reasonable expectation of
    success. IXI IP, LLC v. Samsung Elecs. Co., Ltd., 
    903 F.3d 1257
    , 1262 (Fed. Cir. 2018); ZUP, LLC v. Nash Mfg., Inc.,
    
    896 F.3d 1365
    , 1371 (Fed. Cir. 2018).
    On appeal, Alkem argues that, at least because of FDA
    guidance suggesting the undertaking of polymorph screen-
    ings for pharmaceutical solids, the district court clearly
    erred in finding no motivation to combine. We need not
    address that challenge because Alkem acknowledges that
    it also had to prove a reasonable expectation of success in
    arriving at Form A or, relatedly, it would have been obvious
    to try to find a polymorph of Form B of tapentadol hydro-
    chloride. Based on the district court’s findings of fact, we
    conclude that Alkem has not met those standards. Conse-
    quently, we reject the challenge to the district court’s hold-
    ing that Alkem failed to prove obviousness.
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED             13
    Reasonable Expectation of Success
    The district court did not clearly err in finding that a
    POSA would not have had a reasonable expectation of suc-
    cessfully producing Form A, as claimed in the ’364 patent,
    by using the methods outlined in Byrn on the compound
    disclosed in the ’737 patent (Form B). As an initial matter,
    polymorphism of tapentadol hydrochloride was unknown
    at the time of filing the ’364 patent. Form B was the only
    crystal structure of tapentadol hydrochloride known in the
    art at the time. See J.A. 8567 (267:13–21); 9772–73 (50:11–
    51:10). As the record reflects, polymorphism does not occur
    in all compounds. Depomed Litigation, 
    2016 WL 7163647
    ,
    at *51 (“Dr. Bernstein testified that about 30 to 35% of all
    compounds are polymorphic.”); see also J.A. 57373 (“The
    first step in the polymorph decision tree is . . . to attempt
    to answer the question: Are polymorphs possible?”).
    The Byrn article presents a flow chart that outlines a
    number of variables that may be adjusted during the re-
    crystallization process to determine whether polymor-
    phism occurs in a compound. Figure 1 below is the
    polymorphs tree presented in Byrn.
    14        GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    J.A. 57373. At the outset, Byrn lists a number of solvents
    to be used to recrystallize a substance to first determine
    whether polymorphs are possible. “Solvents should include
    those used in the final recrystallization steps and those
    used during formulation and processing and may also in-
    clude water, methanol, ethanol, propanol, isopropanol, ac-
    etone, acetonitrile, ethyl acetate, hexane and mixtures if
    appropriate.” 
    Id.
     Byrn does not disclose when it would be
    appropriate to use particular solvents or a particular mix-
    ture of solvents for recrystallization.
    Byrn also instructs a POSA to “vary temperature, con-
    centration, agitation, pH.” 
    Id.,
     Figure 1. Dr. Bernstein,
    Cross-Appellants’ expert, testified that when it comes to so-
    lution recrystallization “there’s a huge variety of solvents
    with temperatures, whether you stir or not, and . . . the
    crystallization is generally carried out by cooling. So the
    cooling rate can be a major factor in determining what you
    get.” J.A. 10489–90 (142:24–143:3). But Byrn does not pro-
    vide guidelines regarding which temperature, concentra-
    tion, agitation, or pH levels are likely to result in
    polymorphs of particular compounds. It only notes that
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED               15
    these parameters should be varied. This lack of disclosure
    supports Dr. Bernstein’s testimony that a POSA would
    have to manipulate the variables to “determine what the
    crystal form landscape looks like” because “you don’t know
    what the result’s going to be.” J.A. 10493 (146:11–24). In-
    deed, a POSA could alter any number of variables and still
    fail to find a polymorph of a particular compound. J.A.
    10494 (147:20–25); J.A. 8528 (228:15–21) (noting that pol-
    ymorph investigations require varying parameters like
    temperature and solvents to “extend as broad as possible
    [the] range of investigations.”); see also Pfizer, Inc. v. Apo-
    tex, Inc., 
    480 F.3d 1348
    , 1365 (Fed. Cir. 2007) (“To be sure,
    ‘to have a reasonable expectation of success, one must be
    motivated to do more than merely vary all parameters or
    try each of numerous possible choices until one possibly ar-
    rived at a successful result, where the prior art gave either
    no indication of which parameters were critical or no direc-
    tion as to which of many possible choices is likely to be suc-
    cessful.’” (quoting Medichem, S.A. v. Rolabo, S.L., 
    437 F.3d 1157
    , 1165 (Fed. Cir. 2006)). Consequently, we hold that
    the district court did not clearly err in crediting Dr. Bern-
    stein’s testimony or concluding that Byrn provides insuffi-
    cient guidance in discussing the wide array of conditions
    that could affect recrystallization, and therefore, the crys-
    tal structure of a resulting compound. See Depomed Liti-
    gation, 
    2016 WL 7163647
    , at *52–53.
    Despite the lack of disclosure in Byrn, Alkem argues
    that any polymorph screening of a sample of tapentadol hy-
    drochloride would result in Form A, either in whole or in
    part, because Form A is more stable at room temperature.
    Alkem contends that it is “not disputed” that the synthesis
    described in Example 25 of the ’737 patent resulted in at
    least some Form A. Alkem Br. 34. In other words, Alkem
    asserts a POSA would have likely performed polymorph
    screening on a sample with some Form A if following the
    synthesis steps of Example 25. The record, however, does
    not support Alkem’s argument.
    16        GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    Alkem advanced this same argument before the dis-
    trict court to allege that the ’737 patent inherently antici-
    pates the ’364 patent, an issue that is not before us. The
    district court rejected Alkem’s inherent anticipation theory
    because the method of synthesis that Alkem used, for pur-
    poses of this litigation, to produce a sample of tapentadol
    hydrochloride that comprised a mixture of Form A and
    Form B was not performed in accordance with the three
    steps outlined in Example 25 of the ’737 patent. Depomed
    Litigation, 
    2016 WL 7163647
    , at *45–50. Instead, the mix-
    ture of Form A and Form B that Alkem relied on at trial
    was a result of performing only one of the three steps de-
    scribed in Example 25, whereas testimony showed that
    fully performing each of the three steps outlined in Exam-
    ple 25 results in only Form B. 
    Id. at *46, *48, *50
    ; see also
    J.A. 8557–60 (257:10–260:3) (stating resynthesis of Exam-
    ple 25 resulted in Form B); J.A. 8561 (261:11–19) (Example
    25 resynthesis resulted in Form B and no Form A); J.A.
    10497–10503 (150:20–156:21) (stating faithful reproduc-
    tions of Example 25 result in only Form B, not Form A);
    J.A. 9729–30 (7:16–8:18) (same). Given the weight of evi-
    dence, we do not believe the district court clearly erred in
    concluding that Alkem failed to prove that synthesizing
    tapentadol hydrochloride according to Example 25 of the
    ’737 patent resulted in only Form B. In addition, a POSA
    would not reasonably expect any polymorph screening of
    Form B to necessarily result in the “most stable form” of
    tapentadol hydrochloride (Form A, as Alkem argues). See
    J.A. 9773 (51:6–14) (stating there is no way to predict the
    most stable form without testing). Because the record in-
    dicates that there was (1) no known or expected polymor-
    phism of tapentadol; (2) no evidence that the synthesis of
    Example 25 results in any Form A; and (3) no guidance as
    to what particular solvents, temperatures, agitation rates,
    etc., were likely to result in Form A, Alkem failed to prove
    that a POSA would have reasonably expected a polymorph
    screening of the Form B disclosed in the ’737 patent to re-
    sult in Form A.
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED             17
    Alkem also argues that the district court applied the
    wrong legal standard in its obviousness inquiry, requiring
    “absolute predictability,” as opposed to a reasonable expec-
    tation of success. Indeed, in each of the cases Alkem cites,
    we did not require “absolute predictability,” but acknowl-
    edged that the combination of prior art disclosures resulted
    in a predictable outcome. See Pfizer, 480 F.3d at 1364;
    AstraZeneca LP v. Breath Ltd., 603 F. App’x 999, 1001–02
    (Fed. Cir. 2015) (“Breath”); see also Cubist Pharm., Inc. v.
    Hospira, Inc., 
    805 F.3d 1112
    , 1128–29 (Fed. Cir. 2015).
    However, each of these cases is inapposite to the facts at
    hand.
    For example, in Pfizer, Inc. v. Apotex, Inc., we deter-
    mined that a POSA would have had a reasonable expecta-
    tion of success to make amlodipine besylate based on the
    disclosure of amlodipine and a list of “53 FDA-approved,
    commercially marketed anions.” 480 F.3d at 1355, 1361–
    69. Under the “particularized facts of [Pfizer],” such expec-
    tation was reasonable because a POSA would have nar-
    rowed the list of 53 anions “to a few” due to known
    characteristics of the anions. Id. at 1363, 1366–67. In
    other words, it was reasonable to expect that the combina-
    tion of amlodipine and benzene sulphonate—one of the 53
    anions disclosed the prior art—would likely result in am-
    lodipine besylate because of the known acid strength, solu-
    bility, and other chemical characteristics of the benzene
    sulphonate. Id. at 1363.
    In AstraZeneca LP v. Breath Ltd., we concluded that a
    POSA would have had a reasonable expectation of success
    of producing the claimed sterile budesonide composition
    using known sterilization techniques even if the level of pu-
    rity resulting from the methods was not actually known.
    603 F. App’x at 1001–02. We did not require “actual suc-
    cess” in creating the claimed invention because the record
    abundantly supported the conclusion that four out of five
    known sterilization techniques would result in a sterile
    18        GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    budesonide product that met the purity limitations of the
    claims. Id. at 1002.
    In Cubist Pharmaceuticals, Inc. v. Hospira, Inc., we
    agreed with the district court’s determination that it would
    have been obvious to use well-known purification tech-
    niques to produce a daptomycin-related substance having
    the recited purity levels. 805 F.3d at 1127, 1129. The as-
    serted purity claims in Cubist recited each of the purifica-
    tion techniques that were described in the prior art. Id. at
    1127–29. Using these purification techniques, the purity
    levels disclosed in each of these claims could be achieved.
    Id. at 1128 (“The purity patents do not point to any addi-
    tional techniques that are necessary to obtain the recited
    purity levels in each of the claims.”). Therefore, we con-
    cluded a POSA would have had a reasonable expectation of
    success in achieving the claimed purity levels because the
    purification techniques claimed in the patents used to
    achieve said purity levels were already known in the art.
    Id. at 1129.
    The prior art processes described in Breath and Cubist
    were each known to purify substances, and therefore it was
    reasonably predictable that these methods would result in
    purity levels described in the claims. In Pfizer, the realm
    of possible anions could be reduced to a manageable num-
    ber based on known properties of the anions, thus provid-
    ing a POSA with a reasonable expectation of success. Here,
    a POSA did not know, or have reason to know, that tapen-
    tadol hydrochloride is polymorphic. Nor could a POSA
    know, or have reason to know, how the multiple variables
    involved in conducting a polymorph screen would affect the
    recrystallization of tapentadol hydrochloride. Byrn does
    not provide any guidance as to how the different solvents,
    varying temperatures, rates of agitation, or other variables
    used in polymorph screenings should be manipulated to
    even determine whether polymorphism occurs. Cf. KSR
    Int’l Co. v. Teleflex Inc., 
    550 U.S. 398
    , 417 (2007) (“If a per-
    son of ordinary skill can implement a predictable variation,
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED               19
    § 103 likely bars its patentability.”); DePuy Spine, Inc. v.
    Medtronic Sofamor Danek, Inc., 
    567 F.3d 1314
    , 1326 (Fed.
    Cir. 2009) (noting “predictability is a touchstone of obvious-
    ness”). This lack of knowledge in the field shows there was
    little to no basis from which a POSA could expect a proba-
    bility of success in producing Form A.
    Our decision today does not rule out the possibility that
    polymorph patents could be found obvious. But on the rec-
    ord here, the district court did not clearly err in finding a
    failure to prove that a POSA would have had a reasonable
    expectation of success at arriving at the claimed invention
    based on the prior art. As a result, we hold the district
    court did not commit legal error in concluding the ’364 pa-
    tent is not invalid as obvious.
    Obvious to Try
    Alkem contends that because Byrn discloses a finite
    number of solvents to use for recrystallization, it would
    have been obvious to try to produce Form A of tapentadol
    hydrochloride. To prove obviousness under an obvious to
    try theory, Alkem must show (1) a design or market need
    to solve a particular problem, and (2) that “there are a fi-
    nite number of identified, predictable solutions” that would
    lead to an expectation of success. KSR, 
    550 U.S. at 421
    (emphasis added).
    As stated above, the district court did not clearly err in
    finding that Byrn identified many variables for screening,
    i.e., a “huge number of possible choices,” as opposed to a
    “finite number,” as contemplated in KSR. See Depomed
    Litigation, 
    2016 WL 7163647
    , at *53; see also KSR, 
    550 U.S. at 421
    . Rather, Byrn simply provides “a general ap-
    proach” to polymorph screening, only giving “general guid-
    ance,” without providing “detailed enabling methodology.”
    In re Kubin, 
    561 F.3d 1351
    , 1359–60 (Fed. Cir. 2009) (quot-
    ing In re O’Farrell, 
    853 F.2d 894
    , 902–03 (Fed. Cir. 1988)).
    This court has explained that a conclusion of obviousness
    does not follow from merely “vary[ing] all parameters or
    20        GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    try[ing] each of numerous possible choices until one possi-
    bly arrived at a successful result, where the prior art gave
    either no indication of which parameters were critical or no
    direction as to which of many possible choices is likely to
    be successful.” Id. at 1359 (quoting O’Farrell, 
    853 F.2d at 903
    ). As already explained, the district court did not
    clearly err in finding that a POSA would not have had a
    reasonable expectation of producing Form A using the dis-
    closure of the ’737 patent and Byrn. Therefore, for the rea-
    sons stated above, it would not have been obvious to try to
    produce Form A based on the prior art in the record.
    C. Utility
    We now turn to the question of the ’364 patent’s utility.
    Utility is a question of fact. Stiftung v. Renishaw PLC, 
    945 F.2d 1173
    , 1180 (Fed. Cir. 1991); Raytheon Co. v. Roper
    Corp., 
    724 F.2d 951
    , 956 (Fed. Cir. 1983). The bar for util-
    ity is not high. Juicy Whip, Inc. v. Orange Bang, Inc., 
    185 F.3d 1364
    , 1366 (Fed. Cir. 1999). Nonetheless, a patent
    must have specific and substantial utility. In re Fisher, 
    421 F.3d 1365
    , 1371 (Fed. Cir. 2005) (citing Fujikawa v. Watta-
    nasin, 
    93 F.3d 1559
    , 1563 (Fed. Cir. 1996)). The substan-
    tial requirement, also known as “practical utility,” is
    satisfied when “the claimed invention has a significant and
    presently available benefit to the public.” 
    Id.
     To satisfy
    the specific prong of utility, the claimed invention must
    show that it can “provide a well-defined and particular ben-
    efit to the public.” 
    Id.
     In other words, a patent has utility
    if the alleged invention is capable of providing some iden-
    tifiable benefit presently available to the public. 
    Id.
     A pa-
    tent fails to satisfy the utility requirement under 
    35 U.S.C. § 101
     only if the invention is “totally incapable of achieving
    a useful result.” Brooktree Corp. v. Advanced Micro De-
    vices, Inc., 
    977 F.2d 1555
    , 1571 (Fed. Cir. 1992). For phar-
    maceutical patents, practical utility may be shown by
    evidence of “any pharmacological activity.” Fujikawa, 
    93 F.3d at 1564
    .
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED              21
    Hikma contends that the ’364 patent lacks specific util-
    ity because the specification vaguely states that “Crystal-
    line Form A . . . has the same pharmacological activity as
    Form B but is more stable under ambient conditions. It
    can be advantageously used as [an] active ingredient in
    pharmaceutical compositions.” ’364 patent, col. 4 ll. 13–16.
    Hikma argues this disclosure fails to provide a “well-de-
    fined and particular benefit to the public.” Hikma Br. 32
    (citing In re Fisher, 
    421 F.3d 1365
    , 1371 (Fed. Cir. 2005)).
    Hikma’s arguments are without merit. The ’364 patent
    teaches that “[t]he crystalline Form A according to the in-
    vention is used for the treatment of pain or the treatment
    of urinary incontinence.” ’364 patent, col. 4 ll. 63–65; see
    also 
    id.,
     Abstract. The prior art confirms that tapentadol
    hydrochloride was known as an analgesic at the time of fil-
    ing of the ’364 patent, as does the expert testimony given
    at trial. E.g., J.A. 58128; J.A. 9843 (121:15–17); J.A. 10898
    (21:3–17). Therefore, the ’364 patent concretely discloses
    the practical benefit of Form A of tapentadol hydrochloride
    as an analgesic.
    Hikma next argues that to show substantial utility,
    Form A’s superior stability over Form B at room tempera-
    ture must not only be proven, but must be proven by test
    data. Hikma attempts to set too high a bar for purposes of
    finding a sufficient disclosure of utility. While test results
    often support claims of utility in patents concerning phar-
    macological arts, such testing is not always required. Ras-
    musson v. SmithKline Beecham Corp., 
    413 F.3d 1318
    , 1323
    (Fed. Cir. 2005) (“[I]t is proper for the examiner to ask for
    substantiating evidence unless one with ordinary skill in
    the art would accept the allegations as obviously correct.”
    (quoting In re Jolles, 
    628 F.2d 1322
    , 1325 (CCPA 1980)).
    Nor do said results need to prove the claimed utility. E.g.,
    Fujikawa, 
    93 F.3d at 1564
     (“[T]est results need not abso-
    lutely prove that the compound is pharmacologically ac-
    tive. All that is required is that the tests be reasonably
    indicative of the desired [pharmacological] response.”
    22        GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED
    (internal quotations and citations omitted)). All that is
    necessary is evidence that a POSA would accept the
    claimed utility as correct.
    The district court found that a POSA would have be-
    lieved that, at the time of filing the ’364 patent, Form A
    was more stable than Form B at room temperature, i.e.,
    “ambient conditions.” Example 16 describes a variable
    temperature XRPD experiment that produced Form B from
    Form A at temperatures (40–50º C) higher than room tem-
    perature. ’364 patent, col. 18 ll. 53–57. This effect is “re-
    versible with Form B changing over into Form A at lower
    temperature.” 
    Id.
     col. 18 ll. 56–57. Expert testimony con-
    firmed the results of Example 16, namely that Form A is
    stable at room temperature and Form B is stable above
    50º C. J.A. 10471–72 (124:9–125:6); see also J.A. 9694–96
    (57:14–59:7); J.A. 9800–02 (78:25–80:20). There is suffi-
    cient proof that the disclosure of Example 16 is reasonably
    indicative of the stability of Form A at room temperature.
    There is also sufficient evidence that thermodynamic sta-
    bility is considered beneficial for purposes of storage and
    consistency in manufacturing, which can be beneficial
    characteristics for pharmaceutical compositions. J.A. 9107
    (86:18–23), J.A. 9798 (76:9–12). Cross-appellants need not
    prove that Form A has superior stability over Form B for
    purposes of determining utility. See Demaco Corp. v. F.
    Von Langsdorff Licensing, Ltd., 
    851 F.2d 1387
    , 1390 (Fed.
    Cir. 1988) (“The patent statute does not require that a pa-
    tentable invention be superior to all prior devices.”). It is
    sufficient that Form A is shown to be stable at room tem-
    perature and useful for pain relief.
    For these reasons, we hold that the district court’s find-
    ing of utility was not clearly erroneous.
    Hikma makes additional arguments regarding the va-
    lidity of the ’130 patent to be considered only if this court
    reverses the district court’s findings of noninfringement of
    GRUNENTHAL GMBH v. ALKEM LABORATORIES LIMITED         23
    the ’130 patent. Because we affirm the findings of nonin-
    fringement, we need not reach these issues.
    CONCLUSION
    For the foregoing reasons, we affirm the judgment of
    the district court.
    AFFIRMED
    COSTS
    No costs.