Enzo Life Sciences, Inc. v. Roche Molecular Systems, Inc. , 928 F.3d 1340 ( 2019 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    ENZO LIFE SCIENCES, INC.,
    Plaintiff-Appellant
    v.
    ROCHE MOLECULAR SYSTEMS, INC., ROCHE
    DIAGNOSTICS CORPORATION, ROCHE
    DIAGNOSTICS OPERATIONS, INC., ROCHE
    NIMBLEGEN, INC., BECTON, DICKINSON AND
    COMPANY, AKA BECTON DICKSON AND
    COMPANY, BECTON DICKINSON DIAGNOSTICS
    INC., AKA BECTON DICKSON DIAGNOSTICS,
    GENEOHM SCIENCES INC., ABBOTT
    LABORATORIES, ABBOTT MOLECULAR, INC.,
    Defendants-Appellees
    ______________________
    2017-2498, 2017-2499, 2017-2545, 2017-2546
    ______________________
    Appeals from the United States District Court for the
    District of Delaware in Nos. 1:12-cv-00106-LPS, 1:12-cv-
    00274-LPS, 1:12-cv-00275-LPS, 1:13-cv-00225-LPS, Chief
    Judge Leonard P. Stark.
    ______________________
    SEALED OPINION ISSUED: June 20, 2019
    PUBLIC OPINION ISSUED: July 5, 2019 ∗
    ∗   This opinion was originally filed under seal and has
    been unsealed in full.
    2     ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,
    INC.
    ______________________
    JUSTIN P.D. WILCOX, Desmarais LLP, New York, NY,
    argued for plaintiff-appellant. Also represented by JOHN
    M. DESMARAIS; PETER CURTIS MAGIC, San Francisco, CA.
    MATTHEW WOLF, Arnold & Porter Kaye Scholer LLP,
    Washington, DC, argued for defendants-appellees Roche
    Molecular Systems, Inc., Roche Diagnostics Corporation,
    Roche Diagnostics Operations, Inc., Roche NimbleGen,
    Inc., Becton, Dickinson and Company, Becton Dickinson
    Diagnostics Inc., GeneOhm Sciences Inc.
    JOHN C. O'QUINN, Kirkland & Ellis LLP, Washington,
    DC, argued for defendants-appellees Abbott Laboratories,
    Abbott Molecular, Inc. Also represented by MICHAEL
    PEARSON, JASON M. WILCOX; JAMES F. HURST, AMANDA J.
    HOLLIS, Chicago, IL; BENJAMIN ADAM LASKY, New York,
    NY.
    OMAR KHAN, Wilmer Cutler Pickering Hale and Dorr
    LLP, New York, NY, for defendants-appellees Roche Mo-
    lecular Systems, Inc., Roche Diagnostics Corporation,
    Roche Diagnostics Operations, Inc., Roche NimbleGen,
    Inc., Becton Dickinson and Company, Becton Dickinson Di-
    agnostics Inc., GeneOhm Sciences Inc. Also represented by
    ROBERT J. GUNTHER, JR., CHRISTOPHER R. NOYES; WILLIAM
    G. MCELWAIN, THOMAS SAUNDERS, Washington, DC.
    ______________________
    Before PROST, Chief Judge, REYNA and WALLACH,
    Circuit Judges.
    PROST, Chief Judge.
    Enzo Life Sciences, Inc. (“Enzo”) appeals the decision
    of the U.S. District Court for the District of Delaware
    granting summary judgment against Enzo and holding
    that the asserted claims are invalid for lack of enablement.
    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,          3
    INC.
    We affirm as to non-enablement and do not reach the other
    issues presented on appeal.
    I
    Deoxyribonucleic acid (“DNA”) and ribonucleic acid
    (“RNA”) are nucleic acids. They are made of a series of
    building blocks, called nucleotides, linked together in a
    chain. A single nucleotide is made up of a sugar, a phos-
    phate, and a nitrogenous base. DNA nucleotides have one
    of four nitrogenous bases: adenine (A); guanine (G); cyto-
    sine (C); and thymine (T). RNA has the same bases, except
    it uses uracil (U) instead of thymine (T).
    A polynucleotide refers to multiple nucleotides linked
    together in a chain. 1 The nucleotides located at each end
    of a polynucleotide chain are referred to as terminal nucle-
    otides. All other nucleotides in a polynucleotide chain are
    referred to as internal nucleotides.
    Two strands of polynucleotides can pair with each
    other, i.e., hybridize, through hydrogen bonding between
    the bases on each polynucleotide strand. The bases T and
    U pair with A, while G pairs with C. This is referred to as
    complementary base pairing or “Watson-Crick base pair-
    ing,” and this pairing is how the now-familiar double helix
    shape is formed. Two polynucleotide strands will hybridize
    if the arrangement of nucleotides in each strand is such
    that enough bases can pair with each other. For example,
    whether two strands will hybridize depends in part on the
    number of complementary base pairs that exist between
    the two polynucleotides.
    Hybridization techniques are used to detect the pres-
    ence of certain nucleic acid sequences of interest, i.e., target
    sequences, such as genetic alterations. In such procedures,
    1    An oligonucleotide is simply a shorter polynucleo-
    tide (e.g., just a few nucleotides in length).
    4     ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,
    INC.
    scientists use a hybridization “probe”—i.e., a labeled poly-
    nucleotide that is hybridizable and remains detectable af-
    ter    hybridization     occurs—that     is      sufficiently
    complementary to the target sequence. The probe will hy-
    bridize with the target sequence if the target sequence is
    present, and the label on the probe then allows scientists
    to detect the hybridized probe.
    Nucleic acid hybridization was well understood by
    June 1982, which is the claimed priority date of the patents
    at issue in this appeal. The prevailing method of labeling
    probes at that time was via radioactive labeling. Radioac-
    tive labeling generally involved replacing certain atoms in
    the nucleotide sequence with corresponding radioactive
    isotopes.
    Non-radioactive labeling was just developing at the
    time of the claimed inventions. In 1981, Dr. David Ward
    and others at Yale University successfully developed a non-
    radioactive probe by attaching a label to a polynucleotide
    via a chemical linker at a base position of a nucleotide. See
    J.A. 4129–33 (publication by Dr. Ward and others titled
    “Enzymatic synthesis of biotin-labeled polynucleotides:
    Novel nucleic acid affinity probes”). Dr. Ward demon-
    strated that attaching labels at certain positions of the nu-
    cleotide (“the Ward positions”) would not disrupt the
    polynucleotide’s ability to hybridize and be detected upon
    hybridization.
    In December 1981, Enzo licensed the exclusive rights
    to the patent portfolio covering Dr. Ward’s discovery. See
    J.A. 4258–75. Shortly thereafter, in June 1982, Enzo filed
    a patent application covering non-radioactive labeling at
    additional positions on a nucleotide. The two patents in
    this appeal issued from applications filed in 1995 that
    claim priority from this 1982 application.
    Both patents in this appeal generally relate to the use
    of non-radioactively labeled polynucleotides in nucleic acid
    hybridization and detection applications. The patents
    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,       5
    INC.
    share the same specification in relevant part. See J.A. 90
    n.6.
    A
    U.S. Patent No. 6,992,180 (“the ʼ180 patent”) relates to
    non-radioactive labeling of polynucleotides where the label
    is attached at the phosphate position of a nucleotide. The
    claims are not directed to any specific polynucleotide, nor
    do they focus on the chemistry or linker used to attach a
    label, the number of labels to attach to a polynucleotide, or
    where within the polynucleotide to attach those labels. In-
    stead, the claims encompass all polynucleotides with labels
    attached to a phosphate, as long as the polynucleotide re-
    mains hybridizable and detectable upon hybridization.
    Claim 1 of the ʼ180 patent is representative:
    1. An oligo- or polynucleotide which is complemen-
    tary to a nucleic acid of interest or a portion
    thereof, said oligo- or polynucleotide comprising at
    least one modified nucleotide or modified nu-
    cleotide analog having the formula
    Sig-PM-SM-BASE
    wherein PM is a phosphate moiety, SM is a
    furanosyl moiety and BASE is a base moiety com-
    prising a pyrimidine, a pyrimidine analog, a pu-
    rine, a purine analog, a deazapurine or a
    deazapurine analog wherein said analog can be at-
    tached to or coupled to or incorporated into DNA or
    RNA wherein said analog does not substan-
    tially interfere with double helix formation or
    nucleic acid hybridization, said PM being at-
    tached to SM, said BASE being attached to SM,
    and said Sig being covalently attached to PM
    directly or through a non-nucleotidyl chemical link-
    age, and wherein said Sig comprises a non-polypep-
    tide, non-nucleotidyl, non-radioactive label
    moiety which can be directly or indirectly
    6     ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,
    INC.
    detected when attached to PM or when said
    modified nucleotide is incorporated into said
    oligo- or polynucleotide or when said oligo- or
    polynucleotide is hybridized to said comple-
    mentary nucleic acid of interest or a portion
    thereof, and wherein Sig comprises biotin, imino-
    biotin, an electron dense component, a magnetic
    component, a metal-containing component, a fluo-
    rescent component, a chemiluminescent compo-
    nent, a chromogenic component, a hapten or a
    combination of any of the foregoing.
    ʼ180 patent claim 1 (emphases added).
    “Sig” represents a signaling moiety (i.e., a label); PM
    represents a phosphate moiety; SM represents a sugar moi-
    ety; and BASE represents a base moiety.
    B
    The asserted claims of U.S. Patent No. 8,097,405 (“the
    ʼ405 patent”) fall into two categories: (1) in situ hybridiza-
    tion claims; and (2) liquid phase hybridization claims.
    The in situ hybridization claims (claims 63, 64, 65, 95,
    103, 128, and 144) describe a process that uses a probe non-
    radioactively labeled at any non-Ward position to identify
    chromosomes. In situ hybridization is where probes are
    hybridized to a target that is fixed, usually on a glass slide.
    Claim 64 is exemplary.
    The liquid phase hybridization claims (claims 196 and
    198) describe a process that uses a non-radioactively la-
    beled probe to hybridize and detect a target sequence in a
    liquid medium, rather than on a glass slide. These claims
    cover using probes labeled non-radioactively at any posi-
    tion on the nucleotide, including the three Ward positions.
    The asserted liquid phase hybridization claims depend
    from claim 189.
    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,       7
    INC.
    C
    This consolidated appeal involves four district court
    cases. 2 The ʼ180 patent is at issue in all four cases, while
    the ʼ405 patent is at issue only in the cases against Abbott.
    In January 2012, Enzo filed suit against Roche Molec-
    ular Systems, Inc., Roche Diagnostics Corp., Roche Diag-
    nostics Operations, Inc., and Roche Nimblegen, Inc.
    (collectively, “Roche”) alleging infringement of the ʼ180 pa-
    tent. J.A. 1212–16 (Compl.) (Case No. 1:12-cv-106). In
    March 2012, Enzo filed separate suits against Becton,
    Dickinson and Co., Becton Dickinson Diagnostics Inc., and
    GeneOhm Sciences, Inc. (collectively, “BD”); and Abbott
    Laboratories and Abbott Molecular, Inc. (collectively, “Ab-
    bott”) alleging infringement of the ʼ180 patent. J.A. 2833–
    36 (Compl.) (Case No. 1:12-cv-275 against BD); J.A. 1964–
    67 (Compl.) (Case No. 1:12-cv-274 against Abbott). In Feb-
    ruary 2013, Enzo filed a second suit against Abbott alleging
    infringement of the ʼ405 patent. J.A. 3973–77 (Compl.)
    (Case No. 1:13-cv-225).
    In June 2017, in the cases against Roche and BD, the
    district court denied summary judgment with respect to
    written description, but granted summary judgment in fa-
    vor of the defendants, holding that all asserted claims of
    the ʼ180 patent were invalid as not enabled. See J.A. 59–
    77, 99–117. The district court entered partial final judg-
    ment of invalidity pursuant to Federal Rule of Civil Proce-
    dure 54(b) with respect to the claims of the ʼ180 patent in
    the cases against BD and Roche. J.A. 14–18 (BD), 5–9
    (Roche).
    In the two Abbott cases, Enzo agreed that the district
    court’s earlier enablement ruling as to the ʼ180 patent
    would be deemed to apply to the claims of that patent
    2  Appeal Nos. 17-2354 and 17-2355 were dismissed
    by agreement of the parties in those appeals. ECF No. 98.
    8     ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,
    INC.
    asserted against Abbott. J.A. 23, 14950–51. As to the ʼ405
    patent, in August 2017, the district court denied Abbott’s
    motion as to written description but granted summary
    judgment in favor of Abbott, holding the claims invalid for
    lack of enablement. J.A. 78–98. The district court entered
    final judgment of invalidity of all asserted claims of the
    ʼ180 and ʼ405 patents on September 1, 2017. J.A. 10–13,
    23–26.
    Enzo timely appealed each judgment. This court con-
    solidated the appeals. We have jurisdiction under 28
    U.S.C. § 1295(a)(1).
    II
    In reviewing a grant of summary judgment, we apply
    the law of the regional circuit. Vasudevan Software, Inc. v.
    MicroStrategy, Inc., 
    782 F.3d 671
    , 676 (Fed. Cir. 2015). The
    Third Circuit reviews a district court’s grant of summary
    judgment de novo. Melrose, Inc. v. City of Pittsburgh, 
    613 F.3d 380
    , 387 (3d Cir. 2010). “Summary judgment is ap-
    propriate only where, drawing all reasonable inferences in
    favor of the nonmoving party, there is no genuine issue as
    to any material fact and . . . the moving party is entitled to
    judgment as a matter of law.” 
    Id. (quoting Ruehl
    v. Viacom,
    Inc., 
    500 F.3d 375
    , 380 n.6 (3d Cir. 2007)). “[U]nless there
    is sufficient evidence favoring the nonmoving party for a
    jury to return a verdict for that party,” there is no need for
    a trial, and summary judgment is appropriate. Anderson
    v. Liberty Lobby, Inc., 
    477 U.S. 242
    , 249 (1986).
    III
    The enablement requirement asks whether “the speci-
    fication teach[es] those in the art to make and use the in-
    vention without undue experimentation.” In re Wands, 
    858 F.2d 731
    , 737 (Fed. Cir. 1988). To satisfy this requirement,
    “[t]he specification must contain sufficient disclosure to en-
    able an ordinarily skilled artisan to make and use the en-
    tire scope of the claimed invention at the time of filing.”
    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,            9
    INC.
    MagSil Corp. v. Hitachi Glob. Storage Techs., Inc., 
    687 F.3d 1377
    , 1381 (Fed. Cir. 2012). “Enablement is a question of
    law based on underlying factual findings.” 
    Id. at 1380.
         “To prove that a claim is invalid for lack of enablement,
    a challenger must show by clear and convincing evidence
    that a person of ordinary skill in the art would not be able
    to practice the claimed invention without ‘undue experi-
    mentation.’” Alcon Research Ltd. v. Barr Labs., Inc., 
    745 F.3d 1180
    , 1188 (Fed. Cir. 2014) (quoting In re 
    Wands, 858 F.2d at 736
    –37). 3 In analyzing undue experimentation, we
    consider factors such as: “(1) the quantity of experimenta-
    tion necessary, (2) the amount of direction or guidance pre-
    sented, (3) the presence or absence of working examples,
    (4) the nature of the invention, (5) the state of the prior art,
    (6) the relative skill of those in the art, (7) the predictability
    or unpredictability of the art, and (8) the breadth of the
    claims.” In re 
    Wands, 858 F.2d at 737
    .
    In our view, the issue in this appeal is not simply
    whether the specification enables labeling; the question is
    whether it enables creation of a labeled probe that is both
    hybridizable and detectable upon hybridization. Many of
    the alleged factual disputes raised by Enzo and many of the
    arguments raised by Appellees relate to the details of cre-
    ating the labeled polynucleotide. For example, Roche and
    BD contend that the specification fails to sufficiently dis-
    close internal phosphate labeling. But even if we assume
    that the specification teaches one of skill in the art how to
    create the broad range of labeled polynucleotides covered
    by the claims, as explained below, the specification still
    fails to teach one of skill in the art which combinations will
    3    In this case, the parties agree that the relevant per-
    son of ordinary skill in the art is a scientist with a doctorate
    in chemistry, biochemistry, biophysics, molecular biology,
    or a similar field. Appellant’s Br. 30 (noting the parties’
    agreement).
    10    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,
    INC.
    produce a polynucleotide that is hybridizable and detecta-
    ble upon hybridization, as required by the claim language.
    With this focus on the functionality required by the
    claims, we agree with Appellees that our decision in Wyeth
    and Cordis Corp. v. Abbott Laboratories, 
    720 F.3d 1380
    (Fed. Cir. 2013), controls this case. In Wyeth, we affirmed
    a grant of summary judgment and held the asserted claims
    invalid for lack of enablement because it would have re-
    quired undue experimentation to determine which com-
    pounds in the claimed class would have the required
    functionality. 
    Id. at 1385–86.
    The claims in Wyeth were
    construed to require a compound having certain function-
    ality (e.g., immunosuppressive effects). 
    Id. at 1383.
    The
    claims covered a class of compounds that met those func-
    tional requirements. 
    Id. at 1385.
    The patentee’s witnesses
    testified that minor alterations to the molecule disclosed in
    the specification could impact the required functionality.
    
    Id. The patent
    challengers in that case thus argued that a
    person of ordinary skill in the art would need to screen each
    compound to determine what candidates would have the
    claimed functionality. 
    Id. We agreed.
    Id. We noted 
    the
    breadth of the claims, the limited guidance provided in the
    specification, the large number of possible candidates fall-
    ing within the claimed genus (tens of thousands), and the
    fact that it would be necessary to first synthesize and then
    screen each of those candidates to determine whether it
    had the required functionality. 
    Id. We further
    noted that
    one of the patentee’s scientists had confirmed the unpre-
    dictability in the art by testifying that one would need to
    test each compound to understand whether it would have
    the desired functionality. 
    Id. We thus
    concluded that there
    was no genuine dispute that practicing the full scope of the
    claims would require undue experimentation. 
    Id. The facts
    in this appeal largely mirror those in Wyeth.
    As in Wyeth, the asserted claims here require not just a
    particular structure, but a particular functionality (i.e., the
    labeled polynucleotides must be hybridizable and
    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,        11
    INC.
    detectable upon hybridization). As explained below, the
    specification fails to teach one of skill in the art whether
    the many embodiments of the broad claims would exhibit
    that required functionality.
    The scope of the claims is quite broad. Claim 1 of the
    ʼ180 patent encompasses all phosphate-labeled polynucle-
    otides that are hybridizable and detectable. The claim
    places almost no limitations on the structure of the claimed
    polynucleotide, other than the fact that the label is at-
    tached to the phosphate portion of the nucleotide. It does
    not restrict the chemistry used to attach the label, the
    chemical linker used, the number of labels within a probe,
    or the location of the labels on the probe (i.e., whether they
    are terminal or internal). As to the type of non-radioactive
    label used, the claim provides broad categories, such as any
    “electron dense component” or “magnetic component.”
    The specification’s guidance as to how such variables
    would or would not impact the functionality of the claimed
    probes is sparse. For example, Enzo directs our attention
    to a sentence in the specification that states that “[a] par-
    ticularly important and useful aspect of the special nucleo-
    tides of this invention is the use of such nucleotides in the
    preparation of DNA or RNA probes.” ʼ180 patent col. 54
    ll. 18–20; see also 
    id. col. 54
    ll. 18–33 (describing generally
    how a probe works). Enzo’s expert, Dr. Backman, ex-
    plained that a skilled artisan would have understood this
    reference to using the polynucleotide as a “probe” as mean-
    ing a polynucleotide that is capable of hybridizing and be-
    ing detected upon hybridization.            J.A. 5840–41 ¶ 57
    (Backman Decl.). But at the time of the invention, the art
    was highly unpredictable. As Enzo’s expert explained:
    At the time of the inventions of the ʼ180 patent, it
    was commonly thought that the addition of a non-
    radioactive label to a nucleic acid sequence at posi-
    tions other than a few known as ‘non-disruptive po-
    sitions’ . . . would interfere with or disrupt the
    12     ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,
    INC.
    hybridization process, rendering the nucleotide in-
    effective for diagnostic purposes.
    J.A. 4728 ¶ 74 (Backman Opening Report).
    Given the unpredictability of the art at the time and
    the serious doubts held by those of skill in the art regarding
    whether labels could be attached to non-Ward positions
    without disrupting hybridization, merely stating that a la-
    beled polynucleotide will work as a probe is not sufficient
    to enable one of skill in the art to know that it would indeed
    function as a probe—i.e., be hybridizable and detectable
    upon hybridization.
    Enzo also presents Example V as an example of an in-
    ternal phosphate-labeled polynucleotide that is hybridiza-
    ble and detectable. Appellant’s Br. 32–33. Example V
    states in full:
    Biotin and polybiotinylated poly-L-lysine were cou-
    pled to oligoribonucleotides using a carbodiimide
    coupling procedure described by Halbran and Par-
    ker, J. Immunol., 96 373 (1966). As an example,
    DNA (1 ug/ml), 1 ml) in tris buffer pH 8.2, sheared
    with 0.1 N sodium hydroxide was denatured by
    boiling for 10 minutes and quick cooling in an ice
    bath. Biotinyl-1,6-diaminohexane amide (2 mg, 6
    umol) or polybiotinylated poly-L-lysine (2 mg) and
    l-ethyl-3-diisopropylaminocarboimide HCl (10 mg,
    64 umol) were added, and the pH readjusted to 8.2.
    After 24 hours at room temperature in the dark,
    the mixture was dialyzed against 10 mM tris buff-
    ered saline. DNA was precipitated ethanol.
    ʼ180 patent col. 33 ll. 33–44.
    Appellees contend that Example V is not a working ex-
    ample. During prosecution, Enzo admitted that Example
    V is a “‘paper’, rather than [a] ‘working example[].’”
    J.A. 4703 (stating in an amendment made during prosecu-
    tion that “Applicants have determined that the examples
    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,         13
    INC.
    set forth . . . [except certain examples other than Example
    V] are ‘paper’, rather than ‘working examples’”); J.A. 6657
    (same). Additionally, Enzo’s expert testified that he was
    not aware of Enzo having ever tested a phosphate-labeled
    probe for hybridizability and detectability. J.A. 8547–48
    p. 84 l. 5–p. 85 l. 16 (Backman deposition); J.A. 8551–52
    p. 124 l. 10–p. 125 l. 11 (Backman deposition); see also
    J.A. 6441 p. 133 ll. 6–15 (Backman deposition) (“Q: . . . is
    there any bench experiment disclosed in the ʼ180 patent in
    which the ʼ180 inventors attempted to determine whether
    the product of Example V, that is, the Sig moiety attached
    to an oligo- or polynucleotide could be detected after it had
    hybridized to a compl[e]mentary nucleic acid of interest?
    A. . . . no, they did not do an actual bench experiment to
    that effect.”); 
    id. p. 131
    ll. 7–19. Regardless, even viewing
    Example V as a working example, Example V is insuffi-
    cient to enable the breadth of the claims here, especially in
    light of the unpredictability in the art. 4
    The deficiencies in the description as to enablement
    cannot be cured in this case by looking to the knowledge of
    those skilled in the art at the time of the invention. Alt-
    hough “a specification need not disclose what is well known
    in the art,” that rule is “not a substitute for a basic enabling
    disclosure.” Genentech, Inc. v. Novo Nordisk A/S, 
    108 F.3d 1361
    , 1366 (Fed. Cir. 1997). As we have said before, a pa-
    tentee “cannot simply rely on the knowledge of a person of
    ordinary skill to serve as a substitute for the missing infor-
    mation in the specification.” ALZA Corp. v. Andrx Pharm.,
    4   Nothing stated herein would necessarily disallow
    proper constructive examples, which are intended to fulfill
    both written description and enablement requirements.
    Atlas Powder Co. v. E.I. du Pont De Nemours & Co., 
    750 F.2d 1569
    , 1577 (Fed. Cir. 1984) (“Use of prophetic exam-
    ples, however, does not automatically make a patent non-
    enabling.”).
    14    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,
    INC.
    LLC, 
    603 F.3d 935
    , 941 (Fed. Cir. 2010). And, more im-
    portantly, all parties acknowledge that serious doubts ex-
    isted in the art as to whether the use of non-radioactive
    probes at non-Ward positions would be useful as probes.
    For example, an inventor of the ʼ180 patent who is also
    Enzo’s CEO explained that, at the time, it was thought “ag-
    gressive chemical modification of nucleic acid would lead to
    destruction of his [sic] content.” J.A. 6470 p. 1265 l. 5–
    p. 1266 l. 15 (Dr. Rabbani deposition); see also J.A. 6465
    p. 31 l. 12–p. 33 l. 13 (Dr. Rabbani explaining how more ag-
    gressive modification of the nucleic acid was considered
    “breaking the dogma”). Enzo’s expert, Dr. Backman, also
    pointed out the view of the art at the time, stating that “[a]t
    the time of the inventions of the ’180 patent, it was com-
    monly thought that the addition of a nonradioactive label
    to a nucleic acid sequence at positions other than [the Ward
    positions at the base] would interfere with or disrupt the
    hybridization process.” J.A. 4728 ¶ 74 (Backman’s Opening
    Report); J.A. 4184 ll. 10–24 (Dr. Rabbani deposition). In-
    deed, Enzo’s expert explained that for one of skill in the art
    to be comfortable that a particular polynucleotide would
    work as a probe, “they would need to actually make the
    compound and test it in a hybridization experiment, which
    they would have been dissuaded from doing because of
    Ward.” J.A. 8454 p. 150 ll. 8–15 (Sherman deposition) (dis-
    cussing a polynucleotide labeled at the terminal phosphate
    and using carbodiimide chemistry and biotin); see also
    J.A. 8456 ll. 3–11 (Sherman deposition) (“Q: . . . But if they
    had been motivated to make this probe, non-Ward labeled
    probe, your view is that they would have to make it and
    test it in order to predict whether it would actually hybrid-
    ize as of June 1982, right? A: Well, they would have to
    make it and assure against the prevailing wisdom that it
    could work.”); J.A. 8454–55 p. 150 l. 17–p. 151 l. 18 (Sher-
    man deposition).
    Given such unpredictability in the art, and considering
    the testimony of Enzo’s expert that each labeled
    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,       15
    INC.
    polynucleotide would need to be tested to determine
    whether it is hybridizable and detectable upon hybridiza-
    tion, the breadth of the claims here is particularly concern-
    ing in the enablement inquiry. See In re Fisher, 
    427 F.2d 833
    , 839 (CCPA 1970) (“In cases involving unpredictable
    factors, such as most chemical reactions and physiological
    activity, the scope of enablement obviously varies inversely
    with the degree of unpredictability of the factors in-
    volved.”). Appellees contend that millions of embodiments
    of the claims exist based on the many variables involved in
    creating one of the claimed labeled polynucleotides. Enzo
    disputes this number, arguing it is improperly inflated be-
    cause it counts every possible polynucleotide sequence that
    could exist as a separate embodiment. Even assuming
    Enzo is correct that the length and sequence of the polynu-
    cleotide do not give rise to separate embodiments, the other
    variables (such as the type of label, the type of linker used
    to attach the label, and the location of the labels within the
    polynucleotide) still result in an extremely large number of
    possible embodiments. Indeed, Enzo’s expert explained
    that the number of possible polynucleotides that would fit
    within the limitations of claim 1 would be at least “tens of
    thousands.” J.A. 6438 p. 120 l. 20–p. 121 l. 11 (Backman
    deposition).
    In sum, even if Example V describes one working em-
    bodiment with the claimed functionality, undue experi-
    mentation would still be required with regard to the many
    other embodiments of the claims based on the number of
    possible embodiments and the unpredictability in the art.
    See 
    Genentech, 108 F.3d at 1366
    (“Patent protection is
    granted in return for an enabling disclosure of an inven-
    tion, not for vague intimations of general ideas that may or
    may not be workable.”).
    We conclude by briefly addressing the asserted claims
    of the ʼ405 patent. Those claims are broader than the as-
    serted claims of the ʼ180 patent; rather than covering only
    phosphate-labeled polynucleotides, they also cover labeling
    16    ENZO LIFE SCIENCES, INC. V. ROCHE MOLECULAR SYSTEMS,
    INC.
    at other locations on a nucleotide. Like the claims of the
    ʼ180 patent, the asserted claims of the ʼ405 patent require
    the claimed polynucleotides to be hybridizable and detect-
    able upon hybridization. Because the specification does not
    enable the narrower scope of polynucleotides claimed in the
    ʼ180 patent, it also cannot enable the broader scope of pol-
    ynucleotides claimed in the ʼ405 patent. As such, even
    though the asserted claims of the ʼ405 patent pertain to
    certain processes, the claims are still not enabled for the
    reasons described with respect to the ʼ180 patent.
    In sum, viewing the evidence in the light most favora-
    ble to Enzo, we agree with the district court’s grant of sum-
    mary judgment.
    IV
    For the foregoing reasons, we affirm the district court’s
    grant of summary judgment that the asserted claims of the
    ʼ180 patent and the ʼ405 patent are invalid for lack of ena-
    blement.
    AFFIRMED