Court Opinion

ID: 4659495
Source: CourtListenerOpinion
Date Created: 2021-02-11 16:00:48.681375+00
Date Added: 2024-06-11T08:01:59.897756
License: Public Domain

Case: 20-1074   Document: 132    Page: 1     Filed: 02/11/2021

    United States Court of Appeals
        for the Federal Circuit
                  ______________________

      AMGEN INC., AMGEN MANUFACTURING,
          LIMITED, AMGEN USA, INC.,
               Plaintiffs-Appellants

                            v.

     SANOFI, AVENTISUB LLC, FKA AVENTIS
     PHARMACEUTICALS INC., REGENERON
  PHARMACEUTICALS INC., SANOFI-AVENTIS U.S.
                       LLC,
               Defendants-Appellees
              ______________________

                        2020-1074
                  ______________________

     Appeal from the United States District Court for the
 District of Delaware in Nos. 1:14-cv-01317-RGA, 1:14-cv-
 01349-RGA, 1:14-cv-01393-RGA, 1:14-cv-01414-RGA,
 Judge Richard G. Andrews.
                  ______________________

                Decided: February 11, 2021
                 ______________________

     JEFFREY A. LAMKEN, MoloLamken LLP, Washington,
 DC, argued for plaintiffs-appellants. Also represented by
 SARAH JUSTINE NEWMAN, MICHAEL GREGORY PATTILLO, JR.;
 SARA MARGOLIS, New York, NY; ERICA S. OLSON, Amgen
 Inc., Santa Monica, CA; EMILY JOHNSON, STEVEN TANG,
 STUART WATT, WENDY A. WHITEFORD, Thousand Oaks, CA;
 KEITH HUMMEL, Cravath Swaine & Moore LLP, New York,
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 2                                     AMGEN INC.   v. SANOFI

 NY; WILLIAM G. GAEDE, III, McDermott, Will & Emery
 LLP, Menlo Park, CA; CHRISTOPHER B. MEAD, Schertler
 Onorato & Mead LLP, Washington, DC; JAMES L. HIGGINS,
 MELANIE K. SHARP, Young, Conaway, Stargatt & Taylor
 LLP, Wilmington, DE. Plaintiff-appellant Amgen Inc. also
 represented by SARAH CHAPIN COLUMBIA, McDermott, Will
 & Emery LLP, Boston, MA; LAUREN MARTIN, Quinn Eman-
 uel Urquhart & Sullivan LLP, Boston, MA.

     MATTHEW WOLF, Arnold & Porter Kaye Scholer LLP,
 Washington, DC, argued for defendants-appellees. Also
 represented by VICTORIA REINES; DAVID K. BARR, DANIEL
 REISNER, New York, NY; DEBORAH E. FISHMAN, Palo Alto,
 CA; GEORGE W. HICKS, JR., NATHAN S. MAMMEN, CALVIN
 ALEXANDER SHANK, Kirkland & Ellis LLP, Washington,
 DC. Defendants-appellees Sanofi, Aventisub LLC, Sanofi-
 Aventis U.S. LLC also represented by STEPHANIE
 DONAHUE, Sanofi, Bridgewater, NJ. Defendant-appellee
 Regeneron Pharmaceuticals Inc. also represented by
 LARRY A. COURY, LYNDA NGUYEN, Regeneron Pharmaceu-
 ticals Inc., Tarrytown, NY.

     JORGE A. GOLDSTEIN, Sterne Kessler Goldstein & Fox,
 PLLC, Washington, DC, for amici curiae Bristol-Myers
 Squibb Company, Merck Sharp & Dohme Corp. Also rep-
 resented by KRISTINA CAGGIANO KELLY, ELDORA ELLISON,
 WILLIAM MILLIKEN.

     DUANE CHRISTOPHER MARKS, Eli Lilly and Company,
 Indianapolis, IN, for amicus curiae Eli Lilly and Company.
 Also represented by TONYA COMBS, MARK STEWART,
 GILBERT VOY.

    AMIT THAKORE, White & Case LLP, New York, NY, for
 amicus curiae Pfizer Inc. Also represented by DIMITRIOS T.
 DRIVAS; ELIZABETH K. CHANG, Palo Alto, CA; JEFFREY NEIL
 MYERS, Pfizer Inc., New York, NY.
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 AMGEN INC.   v. SANOFI                                    3

      STANLEY D. LIANG, Tarrytown, NY, as amicus curiae,
 pro se.
                 ______________________

  Before PROST, Chief Judge, LOURIE and HUGHES, Circuit
                         Judges.
 LOURIE, Circuit Judge.
     Amgen Inc., Amgen Manufacturing, Ltd., and Amgen
 USA, Inc. (collectively, “Amgen”) appeal from a decision of
 the United States District Court for the District of Dela-
 ware granting Judgment as a Matter of Law (“JMOL”) of
 lack of enablement of claims 19 and 29 of U.S. Patent
 8,829,165 (the “’165 patent”) and claim 7 of U.S. Patent
 8,859,741 (the “’741 patent”). See Amgen Inc. v. Sanofi,
 No. CV 14-1317-RGA, 2019 WL 4058927, at *1–2, *13 (D.
 Del. Aug. 28, 2019) (“Decision”). For the reasons set forth
 below, we affirm.
                          BACKGROUND
      Elevated low-density lipoprotein (“LDL”) cholesterol is
 linked to heart disease. LDL receptors remove LDL cho-
 lesterol from the blood stream, thus regulating the amount
 of circulating LDL cholesterol. The proprotein convertase
 subtilisin/kexin type 9 (“PCSK9”) enzyme regulates LDL
 receptor degradation. PCSK9 binds to LDL receptors and
 mediates their degradation, thus decreasing the number of
 LDL receptors on a cell’s surface. Antibodies may bind to
 and block PCSK9, allowing LDL receptors to continue reg-
 ulating the amount of circulating LDL cholesterol.
     Amgen owns the ’165 and ’741 patents, which describe
 antibodies that purportedly bind to the PCSK9 protein and
 lower LDL levels by blocking PCSK9 from binding to LDL
 receptors. The ’165 and ’741 patents share a common writ-
 ten description. See Appellants’ Br. 10 n.2. The specifica-
 tion discloses amino acid sequences for twenty-six
 antibodies, including the antibody (designated as “21B12”)
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 4                                            AMGEN INC.   v. SANOFI

 with the generic name of evolocumab, marketed by Amgen
 as Repatha®. See ’165 patent col. 85 ll. 1–43; Appellants’
 Br. 11 n.3. As shown for example in Figure 20A of the ’165
 patent, the specification discloses three-dimensional struc-
 tures for the antibodies designated 21B12 and 31H4 and
 shows where those antibodies bind to PCSK9. The ’165 and
 ’741 patents claim antibodies that bind to one or more of
 fifteen amino acids (i.e., “residues”) of the PCSK9 protein
 and block PCSK9 from binding to LDL receptors.
     The relevant ’165 patent claims are:
     1. An isolated monoclonal antibody, wherein, when
     bound to PCSK9, the monoclonal antibody binds to
     at least one of the following residues: S153, I154,
     P155, R194, D238, A239, I369, S372, D374, C375,
     T377, C378, F379, V380, or S381 of SEQ ID NO:3,
     and wherein the monoclonal antibody blocks bind-
     ing of PCSK9 to LDLR.
     19. The isolated monoclonal antibody of claim 1
     wherein the isolated monoclonal antibody binds to
     at least two of the following residues S153, I154,
     P155, R194, D238, A239, I369, S372, D374, C375,
     T377, C378, F379, V380, or S381 of PCSK9 listed
     in SEQ ID NO:3.
     29. A pharmaceutical composition comprising an
     isolated monoclonal antibody, wherein the isolated
     monoclonal antibody binds to at least two of the fol-
     lowing residues S153, I154, P155, R194, D238,
     A239, I369, S372, D374, C375, T377, C378, F379,
     V380, or S381 of PCSK9 listed in SEQ ID NO: 3
     and blocks the binding of PCSK9 to LDLR by at
     least 80%.
 ’165 patent col. 427 l. 47–col. 430 l. 23.
     The relevant ’741 patent claims are:
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 AMGEN INC.   v. SANOFI                                     5

     1. An isolated monoclonal antibody that binds to
     PCSK9, wherein the isolated monoclonal antibody
     binds an epitope on PCSK9 comprising at least one
     of residues 237 or 238 of SEQ ID NO: 3, and
     wherein the monoclonal antibody blocks binding of
     PCSK9 to LDLR.
     2. The isolated monoclonal antibody of claim 1,
     wherein the isolated monoclonal antibody is a neu-
     tralizing antibody.
     7. The isolated monoclonal antibody of claim 2,
     wherein the epitope is a functional epitope.
 ’741 patent col. 427 ll. 36–57. The claimed antibodies are
 defined by their function: binding to a combinations of sites
 (residues) on the PCSK9 protein, in a range from one resi-
 due to all of them; and blocking the PCSK9/LDLR interac-
 tion.
     This is the second time that these patents have been on
 appeal in our court. Amgen filed suit against Sanofi,
 Aventisub LLC, Regeneron Pharmaceuticals Inc., and
 Sanofi-Aventis U.S. LLC (collectively, “Sanofi”) on Octo-
 ber 17, 2014, alleging infringement of multiple U.S. pa-
 tents, including the ’165 and ’741 patents. Decision at *1.
 Amgen and Sanofi stipulated to infringement of selected
 claims (including ’165 patent claims 19 and 29 and ’741 pa-
 tent claim 7) and tried issues of validity to a jury in March
 2016. Id. During the trial, the district court granted JMOL
 of nonobviousness and of no willful infringement. Id. At
 the close of the trial, the jury determined that the patents
 were not shown to be invalid for lack of enablement and
 written description. Id.
     Sanofi appealed to this court. Relevant to the current
 appeal, we held that the district court erred in its eviden-
 tiary rulings and jury instructions regarding Sanofi’s de-
 fenses that the patents lack written description and
 enablement, and we remanded for a new trial on those
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 6                                       AMGEN INC.   v. SANOFI

 issues. Amgen Inc. v. Sanofi, 872 F.3d 1367, 1381–82
 (Fed. Cir. 2017). We also vacated the permanent injunc-
 tion. Id.
     On remand, the parties tried the issues of written de-
 scription and enablement to the jury. The jury again found
 that Sanofi failed to prove that the asserted claims were
 invalid for lack of written description and enablement.
 Sanofi moved for JMOL and, in the alternative, for a new
 trial. Decision at *1; J.A. 895. The district court granted
 Sanofi’s Motion for JMOL for lack of enablement and de-
 nied the motion for lack of written description. See Deci-
 sion at *17; J.A. 35. The court also conditionally denied
 Sanofi’s motion for a new trial. Id. Amgen timely ap-
 pealed, and we have jurisdiction pursuant to 28 U.S.C.
 § 1295(a)(1). See J.A. 909–10.
                         DISCUSSION
     Whether a claim satisfies the enablement requirement
 of 35 U.S.C. § 112 is a question of law that we review with-
 out deference, although the determination may be based on
 underlying factual findings, which we review for clear er-
 ror. See Alcon Research Ltd. v. Barr Labs., Inc., 745 F.3d
 1180, 1188 (Fed. Cir. 2014). The statutory basis for the en-
 ablement requirement is found in Section 112 of the patent
 statute, which provides in relevant part that a patent’s
 specification must “enable any person skilled in the art . . .
 to make and use” the patented invention. 35 U.S.C.
 § 112(a). The purpose of the enablement requirement is to
 ensure that the public is told how to carry out the inven-
 tion, i.e., to make and use it. We have held that such dis-
 closure must be “at least commensurate with the scope of
 the claims.” Crown Operations Int’l v. Solutia Inc., 289
 F.3d at 1367, 1378–79 (Fed. Cir. 2002) (citing Nat’l Recov-
 ery Techs., Inc. v. Magnetic Separation Sys., 166 F.3d 1190,
 1196 (Fed. Cir. 1999)).
     “To prove that a claim is invalid for lack of enablement,
 a challenger must show by clear and convincing evidence
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 AMGEN INC.   v. SANOFI                                         7

 that a person of ordinary skill in the art would not be able
 to practice the claimed invention without ‘undue experi-
 mentation.’” Alcon Research, 745 F.3d at 1188 (quoting In
 re Wands, 858 F.2d 731, 736–37 (Fed. Cir. 1988)).
 “Whether undue experimentation is needed is not a single,
 simple factual determination, but rather is a conclusion
 reached by weighing many factual considerations.” Wands,
 858 F.2d at 737. Those factual considerations, which have
 come to be known as the “Wands factors,” are:
       (1) the quantity of experimentation necessary,
       (2) the amount of direction or guidance presented,
       (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.
 Id.
      As we have stated elsewhere, “[a]fter the challenger
 has put forward evidence that some experimentation is
 needed to practice the patented claim, the factors set forth
 in Wands then provide the factual considerations that a
 court may consider when determining whether the amount
 of that experimentation is either ‘undue’ or sufficiently rou-
 tine such that an ordinarily skilled artisan would reasona-
 bly be expected to carry it out.” Alcon Research, 745 F.3d
 at 1188 (quoting Wands, 858 F.2d at 737). Although a spec-
 ification does not need to “describe how to make and use
 every possible variant of the claimed invention, when a
 range is claimed, there must be reasonable enablement of
 the scope of the range.” McRO, Inc. v. Bandai Namco
 Games Am. Inc., 959 F.3d 1091, 1100 (Fed. Cir. 2020) (cit-
 ing AK Steel Corp. v. Sollac, 344 F.3d 1234, 1244 (Fed. Cir.
 2003)) (internal citations omitted).
     On appeal, Amgen asks us to reverse the district court’s
 decision holding ’165 patent claims 19 and 29 and ’741 pa-
 tent claim 7 invalid for lack of enablement. Amgen
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 8                                       AMGEN INC.   v. SANOFI

 contends that, under a proper analysis of the Wands fac-
 tors, the claims at issue were enabled because no undue
 experimentation is required to obtain antibodies fully
 within the scope of the claims. Amgen points to expert tes-
 timony purportedly showing that a person of skill in the art
 can make all antibodies within the scope of the claims by
 following a roadmap using anchor antibodies and well-
 known screening techniques as described in the specifica-
 tion or by making conservative amino acid substitutions in
 the twenty-six examples. Amgen argues that the court
 erred by focusing on the effort required to discover and
 make every embodiment of the claims, see Appellants’ Br.
 32 (citing Decision at *7), while failing to recognize that
 Sanofi could not identify any antibody that cannot be made
 by following the specification’s teachings. See Reply Br. 4–
 5; see also McRO, 959 F.3d at 1104 (“[A] usual requirement
 [is] that the challenger identify specifics that are or may be
 within the claim but are not enabled.”). Amgen contends
 that the embodiments in the patent are structurally repre-
 sentative for the purpose of fulfilling the written descrip-
 tion requirement, and such evidence is sufficient to
 indicate a structure/function correlation establishing ena-
 blement. See Reply Br. 23–24.
     Sanofi responds that the district court properly con-
 cluded based on the Wands factors that the claims are not
 enabled because they require undue experimentation. As
 support for its position, Sanofi contends that there are mil-
 lions of antibody candidates within the scope of the claims,
 the disclosures do not provide sufficient guidance, antibody
 generation is unpredictable, and practicing the full scope of
 the claims requires substantial trial and error. See Appel-
 lees’ Br. 17–18, 56. According to Sanofi, the functionally
 defined claims cover a vast scope. See id. at 34–41. Sanofi
 argues that Amgen focused on “the number of antibodies
 actually known to satisfy the claims, when this court’s
 precedents require examining the number of candidates
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 AMGEN INC.   v. SANOFI                                     9

 that must be made and tested to determine whether they
 satisfy the claimed function.” Id. at 18.
     We begin by considering the Wands case itself, which
 has become the “go to” precedent for guidance on enable-
 ment, and which also involved claims relating to antibody
 technology. The broadest claim in Wands “involve[d] im-
 munoassay methods for the detection of hepatitis B surface
 antigen by using high-affinity monoclonal antibodies of the
 IgM isotype.” Wands, 858 F.2d at 733. The U.S. Patent
 and Trademark Office Board of Patent Appeals and Inter-
 ferences had found that undue experimentation would be
 required for one skilled in the art to make the claimed an-
 tibodies used in the methods because “production of high-
 affinity IgM anti-HBsAg antibodies [was] unpredictable
 and unreliable.” Id. at 735. We found, reviewing the facts,
 that the disclosure adequately taught using hybridoma
 technology to produce the needed claimed antibodies. See
 id. at 734. We stated that “no evidence was presented by
 either party on how many hybridomas would be viewed by
 those in the art as requiring undue experimentation to
 screen,” id. at 740, and we accordingly held that the speci-
 fication fully enabled the claimed invention, see id. at 736.
     Importantly, although Wands gave birth to its epony-
 mous factors, Wands did not proclaim that all broad claims
 to antibodies are necessarily enabled. Facts control and, in
 this court, so does the standard of review. In considering
 the Wands factors, the district court compared the present
 case to other cases in which we found lack of enablement
 due to the undue experimentation required to make and
 use the full scope of the claimed compounds that require a
 particular structure and functionality. For example, in Wy-
 eth & Cordis Corp. v. Abbott Laboratories, we held that
 claims covering methods of preventing restenosis with
 compounds having certain functionality requirements
 were invalid for lack of enablement. See 720 F.3d 1380,
 1385–86 (Fed. Cir. 2013). Of particular significance, we
 held that due to the large number of possible candidates
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  10                                      AMGEN INC.   v. SANOFI

  within the scope of the claims and the specification’s corre-
  sponding lack of structural guidance, it would have re-
  quired undue experimentation to synthesize and screen
  each candidate to determine which compounds in the
  claimed class exhibited the claimed functionality. Id.
       Similarly, in Enzo Life Sciences, Inc. v. Roche Molecu-
  lar Systems, Inc., we found that the claims were similar to
  those at issue in Wyeth in that they required both a partic-
  ular structure and functionality, and we held that the spec-
  ification failed to teach one of skill in the art whether the
  many embodiments of the broad claims would exhibit that
  required functionality. See 928 F.3d 1340, 1345–48 (Fed.
  Cir. 2019). And, in Idenix Pharmaceuticals LLC v. Gilead
  Sciences Inc., we affirmed the district court’s determina-
  tion that the claims had both structural and functional lim-
  itations, and that undue experimentation would have been
  required to synthesize and screen the billions of possible
  compounds because, given a lack of guidance across that
  full scope, finding functional compounds would be akin to
  finding a “needle in a haystack.” 941 F.3d 1149, 1160–63,
  1165 (Fed. Cir. 2019); see Idenix Pharms. LLC v. Gilead
  Scis., Inc., 2018 WL 922125 (D. Del. Feb. 16, 2018). The
  district court found that Wyeth, Enzo, and Idenix all sup-
  port its conclusion that the asserted claims lack enable-
  ment. See Decision at *9–13.
      What emerges from our case law is that the enable-
  ment inquiry for claims that include functional require-
  ments can be particularly focused on the breadth of those
  requirements, especially where predictability and guid-
  ance fall short. In particular, it is important to consider
  the quantity of experimentation that would be required to
  make and use, not only the limited number of embodiments
  that the patent discloses, but also the full scope of the
  claim. As we recently explained:
       [C]onducting the Wands analysis has routinely in-
       volved concrete identification of at least some
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  AMGEN INC.   v. SANOFI                                      11

      embodiment or embodiments asserted not to be en-
      abled—including what particular products or pro-
      cesses are or may be within the claim, so that
      breadth is shown concretely and not just as an ab-
      stract possibility, and how much experimentation
      a skilled artisan would have to undertake to make
      and use those products or processes.
  McRO, 959 F.3d at 1100. We then elaborated in a footnote
  that:
      In cases involving claims that state certain struc-
      tural requirements and also require performance of
      some function (e.g., efficacy for a certain purpose),
      we have explained that undue experimentation can
      include undue experimentation in identifying, from
      among the many concretely identified compounds
      that meet the structural requirements, the com-
      pounds that satisfy the functional requirement.
  Id. at 1100 n.2 (citations omitted).
      That reasoning applies here. While functional claim
  limitations are not necessarily precluded in claims that
  meet the enablement requirement, such limitations pose
  high hurdles in fulfilling the enablement requirement for
  claims with broad functional language. See, e.g., Wyeth,
  720 F.3d at 1384 (finding that practicing the full scope of
  the claims would require excessive experimentation); Enzo,
  928 F.3d at 1345 (finding that the specification failed to
  teach whether the many embodiments would be both hy-
  bridizable and detectable upon hybridization); Idenix, 941
  F.3d at 1155–56 (finding that the broad functional limita-
  tion of having efficacy against hepatitis C virus increased
  the number of nucleoside candidates that would need to be
  screened).
      Each appealed claim in this case is a composition claim
  defined, not by structure, but by meeting functional limita-
  tions. We agree with the district court’s finding that the
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  12                                      AMGEN INC.   v. SANOFI

  specification here did not enable preparation of the full
  scope of these double-function claims without undue exper-
  imentation. See Decision at *13. The binding limitation is
  itself enough here to require undue experimentation.
      Turning to the specific Wands factors, we agree with
  the district court that the scope of the claims is broad.
  While in and of itself this does not close the analysis, the
  district court properly considered that these claims were
  indisputably broad. The parties dispute the exact number
  of embodiments falling within the claims. However, we are
  not concerned simply with the number of embodiments but
  also with their functional breadth. Regardless of the exact
  number of embodiments, it is clear that the claims are far
  broader in functional diversity than the disclosed exam-
  ples. 1 If the genus is analogized to a plot of land, the dis-
  closed species and guidance “only abide in a corner of the
  genus.” AbbVie Deutschland GmbH & Co. v. Janssen Bio-
  tech, Inc., 759 F.3d 1285, 1299–300 (Fed. Cir. 2014). Fur-
  ther, the use of broad functional claim limitations raises
  the bar for enablement, a bar that the district court found
  was not met.
       We also agree with the district court that this invention
  is in an unpredictable field of science with respect to satis-
  fying the full scope of the functional limitations. One of
  Amgen’s expert witnesses admitted that translating an an-
  tibody’s amino acid “sequence into a known three-dimen-
  sional structure is still not possible.” J.A. 3910; see also
  Decision at *9. Another of Amgen’s experts conceded that
  “substitutions in the amino acid sequence of an antibody
  can affect the antibody’s function, and testing would be

       1   For example, there are three claimed residues to
  which not one disclosed example binds. See J.A. 4283; Ap-
  pellees’ Br. 52. And although the claims include antibodies
  that bind up to sixteen residues, none of Amgen’s examples
  binds more than nine. See id.
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  AMGEN INC.   v. SANOFI                                   13

  required to ensure that a substitution does not alter the
  binding and blocking functions.” J.A. 3891; see also Deci-
  sion at *9. And while some need for testing by itself might
  not indicate a lack of enablement, we note here the conspic-
  uous absence of nonconclusory evidence that the full scope
  of the broad claims can predictably be generated by the de-
  scribed methods. Instead, we have evidence only that a
  small subset of examples of antibodies can predictably be
  generated.
      Although the specification provides some guidance, in-
  cluding data regarding certain embodiments, we agree
  with the district court that “[a]fter considering the dis-
  closed roadmap in light of the unpredictability of the art,
  any reasonable factfinder would conclude that the patent
  does not provide significant guidance or direction to a per-
  son of ordinary skill in the art for the full scope of the
  claims.” Decision at *11. Here, even assuming that the
  patent’s “roadmap” provided guidance for making antibod-
  ies with binding properties similar to those of the working
  examples, no reasonable factfinder could conclude that
  there was adequate guidance beyond the narrow scope of
  the working examples that the patent’s “roadmap” pro-
  duced.
       As the district court noted, the only ways for a person
  of ordinary skill to discover undisclosed claimed embodi-
  ments would be through either “trial and error, by making
  changes to the disclosed antibodies and then screening
  those antibodies for the desired binding and blocking prop-
  erties,” or else “by discovering the antibodies de novo” ac-
  cording to a randomization-and-screening “roadmap.” Id.
  Either way, we agree with the district court that the re-
  quired experimentation “would take a substantial amount
  of time and effort.” Id. at *12. We do not hold that the
  effort required to exhaust a genus is dispositive. It is ap-
  propriate, however, to look at the amount of effort needed
  to obtain embodiments outside the scope of the disclosed
  examples and guidance. The functional limitations here
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  14                                      AMGEN INC.   v. SANOFI

  are broad, the disclosed examples and guidance are nar-
  row, and no reasonable jury could conclude under these
  facts that anything but “substantial time and effort” would
  be required to reach the full scope of claimed embodiments.
      We therefore conclude that, after weighing the Wands
  factors, the court did not err in concluding that undue ex-
  perimentation would be required to practice the full scope
  of these claims.
       Finally, Amgen is incorrect that the district court’s de-
  cision is inconsistent with Wands or that our affirmance
  here would overrule Wands. Wands, as indicated above,
  does not hold that antibody screening never requires undue
  experimentation. The holding in Wands was based on the
  facts of that case and the evidence presented there. Here,
  the evidence showed that the scope of the claims encom-
  passes millions of candidates claimed with respect to mul-
  tiple specific functions, and that it would be necessary to
  first generate and then screen each candidate antibody to
  determine whether it meets the double-function claim lim-
  itations. See Decision at *7–13. The facts of this case are
  thus more analogous to those in Enzo, Wyeth, and Idenix,
  where we concluded a lack of enablement.
                          CONCLUSION
      We have considered Amgen’s remaining arguments but
  find them unpersuasive. For the reasons above, we affirm
  the district court’s determination that the asserted claims
  are invalid for lack of enablement.
                          AFFIRMED