Court Opinion

ID: 9914533
Source: CourtListenerOpinion
Date Created: 2024-01-02 16:01:13.433994+00
Date Added: 2024-06-11T13:13:24.160919
License: Public Domain

Case: 22-1946    Document: 48     Page: 1   Filed: 01/02/2024

        NOTE: This disposition is nonprecedential.

   United States Court of Appeals
       for the Federal Circuit
                  ______________________

  PURECIRCLE USA INC., PURECIRCLE SDN BHD,
              Plaintiffs-Appellants

                             v.

 SWEEGEN, INC., PHYTO TECH CORP., DBA BLUE
                 CALIFORNIA,
             Defendants-Appellees
            ______________________

                        2022-1946
                  ______________________

    Appeal from the United States District Court for the
 Central District of California in No. 8:18-cv-01679-JVS-
 JDE, Judge James V. Selna.
                  ______________________

                 Decided: January 2, 2024
                  ______________________

     STANLEY JOSEPH PANIKOWSKI, III, DLA Piper US LLP,
 San Diego, CA, argued for plaintiffs-appellants. Also rep-
 resented by RICHARD T. MULLOY; STUART ERIC POLLACK,
 Kilpatrick Townsend & Stockton LLP, New York, NY.

     JOHN CHRISTOPHER ROZENDAAL, Sterne Kessler Gold-
 stein & Fox PLLC, Washington, DC, argued for defend-
 ants-appellees. Also represented by MICHAEL E. JOFFRE,
Case: 22-1946     Document: 48      Page: 2    Filed: 01/02/2024

 2                       PURECIRCLE USA INC. v. SWEEGEN, INC.

 ANNA G. PHILLIPS, SASHA RAO, DENNIES VARUGHESE,
 DEIRDRE M. WELLS.
               ______________________

      Before DYK, SCHALL, and STARK, Circuit Judges.
 DYK, Circuit Judge.
      PureCircle USA Inc. and PureCircle Sdn Bhd (collec-
 tively, “PureCircle”), the owners of U.S. Patent Nos.
 9,243,273 (“’273 patent”) and 10,485,257 (“’257 patent”),
 brought suit for infringement against defendants Swee-
 Gen, Inc. and Phyto Tech Corp. d/b/a Blue California (col-
 lectively, “SweeGen”). The District Court for the Central
 District of California granted summary judgment to de-
 fendants, concluding that all claims of the asserted patents
 were invalid due to a lack of written description, and that
 claims 1–11 and 14 of the ’273 patent and claims 1–5 of the
 ’257 patent were unpatentable under 35 U.S.C. § 101. We
 conclude that claims 1–13 of the ’273 patent and all claims
 of the ’257 patent are invalid for lack of written description,
 and we also conclude that claim 14 of the ’273 patent is un-
 patentable under § 101. We affirm.
                         BACKGROUND
     Steviol glycosides are naturally occurring compounds
 found in stevia plants that can be used as non-caloric
 sweeteners. One particular steviol glycoside, known as Re-
 baudioside X (“Reb X”) or Rebaudioside M (“Reb M”), was
 identified in trace amounts in stevia plants. Because only
 small amounts of Reb X naturally occur in stevia plants, it
 would be expensive and inefficient to extract Reb X from
 the plants. PureCircle’s two patents at issue in this case,
 U.S. Patent Nos. 9,243,273 and 10,485,257, claim a method
 of producing Reb X using enzymes called UDP-
 glucosyltransferases (“UGTs”), the same enzymes used in
 plants to synthesize the compound. Claims 1 and 14 of the
 ’273 patent are representative, and provide:
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 PURECIRCLE USA INC. v. SWEEGEN, INC.                       3

     1. A method for making Rebaudioside X comprising
     a step of converting Rebaudioside D to Rebaudi-
     oside X using a UDP-glucosyltransferase, wherein
     the conversion of Rebaudioside D to Rebaudioside
     X is at least about 50% complete.
     14. The method of claim 1, wherein the UDP-
     glucosyltransferase comprises UGT76G1.
      PureCircle filed suit in district court against defend-
 ants alleging infringement of the ’273 and ’257 patents.
 The parties stipulated to the claim construction of UGTs as
 “[a] type of enzyme that is capable of transferring a glucose
 unit from a uridine diphosphate glucose molecule to a ste-
 viol glycoside molecule.” J.A. 5159–60. The district court
 held that based on the parties’ stipulation, the term was
 functionally defined. SweeGen moved for summary judg-
 ment of invalidity for lack of written description under 35
 U.S.C. § 112 and subject matter ineligibility under 35
 U.S.C. § 101. The district court partially granted Swee-
 Gen’s motion, finding all claims of the ’273 and ’257 patents
 invalid due to a lack of written description and claims 1–
 11 and 14 of the ’273 patent and claims 1–5 of the ’257 pa-
 tent unpatentable under § 101. PureCircle appeals.
     We have jurisdiction under 28 U.S.C. § 1295(a)(1).
                         DISCUSSION
     We review the grant of summary judgment de novo.
 E.g., Monzon v. City of Murrieta, 978 F.3d 1150, 1155 (9th
 Cir. 2020). “A grant of summary judgment is ‘proper only
 where there is no genuine issue of any material fact or
 where viewing the evidence and the inferences which may
 be drawn therefrom in the light most favorable to the ad-
 verse party, the movant is clearly entitled to prevail as a
 matter of law.’” Clarkson v. Alaska Airlines, Inc., 59 F.4th
 424, 432 (9th Cir. 2023) (quoting Sandvik v. Alaska Packers
 Ass’n, 609 F.2d 969, 974 (9th Cir. 1979)).
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 4                      PURECIRCLE USA INC. v. SWEEGEN, INC.

                               I
     Section 112 requires that a patent’s “specification shall
 contain a written description of the invention.” 35 U.S.C.
 § 112(a). To satisfy the written description requirement,
 the specification must “clearly allow persons of ordinary
 skill in the art to recognize that [the inventor] invented
 what is claimed.” Ariad Pharms., Inc. v. Eli Lilly & Co.,
 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc) (alteration
 in original) (quoting Vas-Cath Inc. v. Mahurkar, 935 F.2d
 1555, 1563 (Fed. Cir. 1991)). That is it must “reasonably
 convey[] to those skilled in the art that the inventor had
 possession of the claimed subject matter as of the filing
 date.” Id. “What is required to meet the written descrip-
 tion requirement ‘varies with the nature and scope of the
 invention at issue, and with the scientific and technologic
 knowledge already in existence.’” Juno Therapeutics, Inc.
 v. Kite Pharma, Inc., 10 F.4th 1330, 1335 (Fed. Cir. 2021)
 (quoting Capon v. Eshhar, 418 F.3d 1349, 1357 (Fed. Cir.
 2005)). For genus claims the specification must “provide
 sufficient ‘blaze marks’ to guide a reader through the forest
 of disclosed possibilities toward the claimed compound.”
 Novozymes A/S v. DuPont Nutrition Biosciences APS, 723
 F.3d 1336, 1346 (Fed. Cir. 2013) (quoting In re Ruschig, 379
 F.2d 990, 995 (C.C.P.A. 1967)).
     In the context of a genus claim, written description “re-
 quires the disclosure of either a representative number of
 species falling within the scope of the genus or structural
 features common to the members of the genus so that one
 of skill in the art can ‘visualize or recognize’ the members
 of the genus.” Ariad, 598 F.3d at 1350 (quoting Regents of
 the Univ. of California v. Eli Lilly & Co., 119 F.3d 1559,
 1568–69 (Fed. Cir. 1997)). The claims of the ’273 and ’257
 patents are properly construed as genus claims using func-
 tional language, as the district court concluded. The pa-
 tents claim a genus of UGT enzymes, and PureCircle and
 SweeGen stipulated to a construction of UGTs that defines
 the enzyme by what it does, i.e., its function – transferring
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 PURECIRCLE USA INC. v. SWEEGEN, INC.                        5

 a glucose unit from a uridine diphosphate glucose molecule
 to a steviol glycoside molecule.
      SweeGen argues that the ’273 and ’257 patents are in-
 valid because they do not disclose a representative number
 of species nor common structural features of the claimed
 UGT genus to identify which enzymes would function to
 convert Reb D to Reb X at a 50% completion level or
 higher. 1 SweeGen contends that the claim language covers
 at least one trillion enzymes that could potentially perform
 that function. 2 SweeGen’s expert reached this number by
 assuming UGT enzymes consisted of 100 amino acids,
 there were 733 known UGT sequences as of 2012, five
 amino acids could be substituted to make mutations, and
 each substitution could consist of 19 different amino acids.
 SweeGen further argues that while the genus claimed is
 enormous, only one enzyme (UGT76G1) was given as a rep-
 resentative species. There is no dispute that the common
 specification of the ’273 and ’257 patents identifies only one
 UGT that it says can make Reb X. Because only one en-
 zyme of the potentially vast class of UGTs is disclosed,
 SweeGen argues, the patent does not disclose a representa-
 tive number of species. SweeGen also argues that there
 was no known common structure of UGTs as of the patent’s
 priority date.

     1    Claim 11 recites “[t]he method of claim 1, wherein
 the conversion is at least about 95% complete.” ’273 patent,
 col. 36, ll. 9–10.
      2   SweeGen contends this is an underestimate be-
 cause the claims also cover fusion enzymes. Fusion en-
 zymes are two or more individual enzyme segments linked
 together to form a single enzyme. In this case, the parties
 dispute whether any enzyme fused with UGT76G1 would
 count as separate enzymes for purposes of written descrip-
 tion. For the purposes of this opinion, we assume they are
 not.
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 6                      PURECIRCLE USA INC. v. SWEEGEN, INC.

     PureCircle contends that the potential trillions of en-
 zymes claimed by SweeGen can drastically be reduced.
 There were only five known enzymes that had been shown
 to be capable of steviol glycoside synthesis, i.e., enzymes
 that come within the scope of the claims. 3 While each of
 these enzymes would have a large number of mutations,
 PureCircle argues that the mutations capable of the re-
 quired synthesis can be determined with reasonable cer-
 tainty through homology modeling. Homology modeling
 consists of entering the amino acid sequence of an enzyme
 into the modeling program, then (based on the amino acid
 sequence) the computer predicts how the enzyme will fold,
 ultimately producing a 3-D model of the enzyme. Looking
 at the model of a working enzyme, PureCircle argues, a
 person of ordinary skill in the art (POSA) could find the
 active site where that enzyme converts Reb D to Reb X, and
 then compare the structure of that active site to the struc-
 ture of mutant enzymes. If the structure of the active sites
 is the same, then the mutant enzyme is likely capable of
 the conversion of Reb D into Reb X.
     Using such modeling, PureCircle provided evidence
 that there were only 1,800 possible mutations for each of
 the five known enzymes, or a total of 9,000 possible UGTs.
 While these mutants would have to be tested to ascertain

     3    A total of twelve enzymes were known to belong to
 the family named UGTs. Only one of the five enzymes,
 UGT76G1, was known to produce Reb X. While the patent
 cites one other UGT enzyme, UGT91D2, and contains a nu-
 cleic acid sequence of that enzyme, the patents do not indi-
 cate that UGT91D2 can convert Reb D to Reb X. See J.A.
 92-93 at col. 2, l. 66–col. 3, l. 3. By contrast, the patents
 explicitly state that UGT76G1 is a UGT “capable of adding
 at least one glucose unit to rebaudioside D to form rebau-
 dioside X.” See J.A. 93 at col. 3, ll.4–6.
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 PURECIRCLE USA INC. v. SWEEGEN, INC.                        7

 if they could actually convert Reb D to Reb X, PureCircle
 argues that such testing was routine.
                               II
      PureCircle argues that disclosure of a single enzyme
 can satisfy the written description requirement, and that
 under our cases, disclosure of a single compound (here, a
 single enzyme) may be representative of the genus. See,
 e.g., Invitrogen Corp. v. Clontech Labs., Inc., 429 F.3d 1052,
 1073 (Fed. Cir. 2005); Bilstad v. Wakalopulos, 386 F.3d
 1116, 1124 (Fed. Cir. 2004) (“[T]his court has continued to
 apply the rule that disclosure of a species may be sufficient
 written description support for a later claimed genus in-
 cluding that species.”). While a single example can provide
 written description support for a genus, that is not the case
 unless the specification provides the required “blaze
 marks.” 4
      PureCircle contends that the single disclosed enzyme
 here is representative of the genus because the structure of
 its active site was common to all claimed UGTs. In other
 words, PureCircle contends that the compound here (the
 UGT76G1 enzyme) discloses common structural features
 sufficient to define the genus.

     4   See, e.g., LizardTech, Inc. v. Earth Res. Mapping,
 Inc., 424 F.3d 1336, 1346 (“Thus, a patentee cannot always
 satisfy the requirements of section 112, in supporting ex-
 pansive claim language, merely by clearly describing one
 embodiment of the thing claimed.”); Juno, 10 F.4th at 1337
 (“The disclosure of one scFv that binds to CD19 and one
 scFv that binds to a PSMA antigen on prostate cancer cells
 in the manner provided in this patent does not provide in-
 formation sufficient to establish that a skilled artisan
 would understand how to identify the species of scFvs ca-
 pable of binding to the limitless number of targets as the
 claims require.”).
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 8                        PURECIRCLE USA INC. v. SWEEGEN, INC.

      Construing the evidence in the light most favorable to
 PureCircle, it is clear that any structural features common
 to the members of the genus were not sufficiently disclosed
 so as to allow one of skill in the art to visualize or recognize
 the members of the genus. First, there is no mention in the
 claims or specification of homology modeling for determin-
 ing common structure. PureCircle argues that homology
 modeling does not need to be disclosed because it was al-
 ready a known technique to a POSA. 5 Even if homology
 modeling did not need to be disclosed in the specification,
 even for the five known enzymes, extensive trial and error
 testing after homology modeling (which by PureCircle’s ad-
 mission would result in 9,000 compounds) would be re-
 quired to identify potential active candidates. In general
 the need for extensive trial and error testing argues
 against a finding of adequate written description. Our de-
 cision in Novozymes is instructive. There, the patentee ar-
 gued that “one of ordinary skill in the art . . . would have
 known how to test every possible variant at that position
 and thus would have found the claimed variants as a mat-
 ter of course.” 723 F.3d at 1350. We explained that “[t]he
 question before us is not whether one of ordinary skill in
 the art presented with the [relevant] application would
 have been enabled to take those final steps, but whether
 the [relevant] application ‘discloses the [variants] to him,
 specifically, as something appellants actually invented.’”
 Id. (second alteration in original) (quoting Ruschig, 379
 F.2d at 995). 6

     5   Compare Capon, 418 F.3d at 1358 (“When the prior
 art includes the nucleotide information, precedent does not
 set a per se rule that the information must be determined
 afresh.”) (emphasis in original).
     6   See also In re Alonso, 545 F.3d 1015, 1020 (Fed. Cir.
 2008) (“[I]t is not enough to describe[] the procedure for
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 PURECIRCLE USA INC. v. SWEEGEN, INC.                       9

      Second, there are potentially additional unknown en-
 zymes that could achieve the conversion to produce Reb X,
 as PureCircle admits. 7 These additional enzymes would
 not necessarily share common structure with UGT76G1.
 The specification contains the amino acid sequence of
 UGT76G1, but it does not identify which part of the amino
 acid sequence is necessary for the conversion function of
 the enzyme. PureCircle repeatedly points to testimony by
 its expert, Dr. Bollinger, that UGTs “all had common struc-
 tural features,” J.A. 5570 ¶ 286, though inconsistently stat-
 ing that “no experimentally determined structure of a
 UDP-glucosyltransferase was known in 2012.” J.A. 5571
 ¶ 290. However, Dr. Bollinger did not relate any common
 structure to the function of the enzyme, other than to men-
 tion homology modeling. If other enzymes do exist, Pure-
 Circle admits that homology modeling cannot be used to

 making a human-human hybridoma from neurofibrosar-
 coma, and teach how to determine whether a given anti-
 body, specific to a patient’s neurofibrosarcoma, will
 function in the claimed method.”); Univ. of Rochester v.
 G.D. Searle & Co., 358 F.3d 916, 925 (Fed. Cir. 2004)
 (“[O]ne of skill in the art would [not], from reading the pa-
 tent, understand what compound or compounds—which, as
 the patent makes clear, are necessary to practice the
 claimed method—would be suitable, nor would one know
 how to find such a compound except through trial and er-
 ror.” (citation omitted)).
      7   THE COURT: “And then, there is the possibility
 that in the future that additional enzymes would be iden-
 tified which achieve the conversion and the claims would
 cover those new enzymes as well, right?”
          COUNSEL FOR PURECIRCLE: “Correct your
 Honor.”
 Oral Argument at 1:17–1:31.
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 10                     PURECIRCLE USA INC. v. SWEEGEN, INC.

 identify those unknown enzymes. 8 Homology modeling
 alone cannot determine what structural features are com-
 mon to enzymes capable of producing Reb X. It can only
 create 3-D structures of enzymes with known amino acid
 sequences which can be used by a POSA to determine com-
 mon structures of mutants of a known enzyme, not the
 structures of other enzymes.
     As to other enzymes that could perform the function,
 PureCircle offered no evidence as to whether it was likely
 or unlikely that those additional enzymes exist or what
 their structure might be. In our prior cases where there
 has been a large genus, encompassing both known and un-
 known compounds, we have held that in order for the dis-
 closed species to be representative of the genus, it has to
 provide blaze marks that would allow a POSA to identify
 other members of the genus. No such blaze marks are pre-
 sent here.
     In Juno, the patent claimed a large genus of “any scFv
 for binding any target.” Juno, 10 F.4th at 1336. We ex-
 plained that “[t]o satisfy written description, however, the
 inventors needed to convey that they possessed the claimed
 invention, which encompasses all scFvs, known and un-
 known, as part of the claimed [chimeric antigen receptor]
 CAR that bind to a selected target.” Id. at 1338. We held
 written description was not satisfied because “the specifi-
 cation provides no means of distinguishing which scFvs
 will bind to which targets,” id., and the patent “contains no
 details about these scFv species beyond the alphanumeric

      8  THE COURT: “But as I understand it, homology
 modeling would not help you identify other enzymes, not
 mutations, but other enzymes besides the four or five that
 perform the conversion, correct?”
         COUNSEL FOR PURECIRCLE: “Correct your
 Honor.”
 Oral Argument at 15:26–15:41.
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 PURECIRCLE USA INC. v. SWEEGEN, INC.                      11

 designations J591 and SJ25C1 for a skilled artisan to de-
 termine how or whether they are representative of the en-
 tire claimed genus,” id. at 1336. Apart from the one specific
 example, here, as in Ariad, 598 F.3d at 1353, “[s]uch claims
 merely recite a description of the problem to be solved
 while claiming all solutions to it and . . . cover any com-
 pound later actually invented and determined to fall within
 the claim’s functional boundaries—leaving it to the phar-
 maceutical industry to complete an unfinished invention.”
     In short, the one enzyme disclosed in the patents here
 has not been shown to be typical of the entire genus of
 UGTs claimed. 9 Under such circumstances, there is no ad-
 equate written description. In AbbVie, we found a lack of
 written description because “AbbVie’s patents only de-
 scribe one type of structurally similar antibodies and []
 those antibodies are not representative of the full variety
 or scope of the genus.” AbbVie Deutschland GmbH & Co.,
 KG v. Janssen Biotech, Inc., 759 F.3d 1285, 1300 (Fed. Cir.
 2014). Likewise, in Idenix, we held that because the pa-
 tents provided “lists or examples of supposedly effective nu-
 cleosides, but d[id] not explain what makes them effective,
 or why . . . a POSA is deprived of any meaningful guidance
 into what compounds beyond the examples and formulas,
 if any, would provide the same result.” Idenix Pharms.

     9   PureCircle points to a decision by the United States
 Patent and Trademark Office (“PTO”) denying post-grant
 review because it found that it was more likely than not
 that written description was satisfied. A decision from the
 PTO “may be persuasive but it is not binding precedent on
 this court.” Noelle v. Lederman, 355 F.3d 1343, 1350 (Fed.
 Cir. 2004). Here, the PTO misunderstood the limits of ho-
 mology modeling and did not take into account that un-
 known enzymes could convert Reb D to Reb X.
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 12                     PURECIRCLE USA INC. v. SWEEGEN, INC.

 LLC v. Gilead Scis. Inc., 941 F.3d 1149, 1164 (Fed. Cir.
 2019). 10
     PureCircle finally contends that the original claims
 doctrine provides sufficient written description support.
 However, the claims of the original application—Applica-
 tion No. PCT/US2013/030439—do not help PureCircle be-
 cause they do not provide any additional information about
 common structural features or representative species of
 the genus. “If a purported description of an invention does

      10  PureCircle relies on Ajinomoto Co. v. Int’l Trade
 Comm’n, 932 F.3d 1342, 1360 (Fed. Cir. 2019) for the prop-
 osition that the knowledge of a POSA should be taken into
 account. Ajinomoto is inapposite. In Ajinomoto, the patent
 claimed a “more potent promoter” but disclosed four exam-
 ples of promoters and cited an article that “provide[d] data
 about the relative strength of fourteen promoters and de-
 scribe[d] a general methodology for determining promoter
 strength.” 932 F.3d at 1347, 1359. Further, there was a
 “well-known link between consensus sequence and pro-
 moter strength” as “promoters having fewer departures
 from a ‘consensus sequence’ in a promoter are generally
 stronger” and “the genus of more potent promoters was al-
 ready well explored in the relevant art.” Id. at 1359–60.
 Even though there was some evidence that “deviations
 from [the consensus] sequence d[id] not always decrease
 promoter strength,” this Court held that “[a]dequate writ-
 ten description does not require a perfect correspondence
 between the members of the genus and the asserted com-
 mon structural feature.” Id. at 1360. Thus, Ajinomoto
 stands for the idea that where there are structural features
 common to a genus, the structure-function correlation does
 not need to be perfect and some testing—appropriate to the
 knowledge of a POSA—is allowed, not that an unknown
 structure-function correlation along with extensive testing
 can satisfy written description.
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 PURECIRCLE USA INC. v. SWEEGEN, INC.                      13

 not meet the requirements of the statute, the fact that it
 appears as an original claim or in the specification does not
 save it. A claim does not become more descriptive by its
 repetition, or its longevity.” Enzo Biochem, Inc. v. Gen-
 Probe Inc., 323 F.3d 956, 968–69 (Fed. Cir. 2002). Thus,
 the original claims doctrine does not provide adequate
 written description support.
      Under these circumstances, we hold that claims 1-13 of
 the ’273 patent and claims 1-7 of the ’257 patent are invalid
 for lack of written description.
                              III
      PureCircle contends that even if the other claims lack
 written description support, claim 14 of the ’273 patent sat-
 isfies the written description requirement because, unlike
 the other claims, it names a specific enzyme, UGT76G1.
 Thus, PureCircle argues, through homology modeling only
 1,800 possible mutations would be covered and testing that
 small group of enzymes for functionality does not run afoul
 of the written description requirement. We need not decide
 that issue, because we conclude that, as the district court
 held, claim 14 is unpatentable under § 101.
      Section 101 of Title 35 provides that “any new and use-
 ful process, machine, manufacture, or composition of mat-
 ter, or any new and useful improvement thereof” is patent-
 eligible subject matter. 35 U.S.C. § 101. However, the Su-
 preme Court has recognized an important exception, and
 “[l]aws of nature, natural phenomena, and abstract ideas
 are not patentable.” Ass’n for Molecular Pathology v. Myr-
 iad Genetics, Inc., 569 U.S. 576, 589 (2013) (quoting Mayo
 Collaborative Servs. v. Prometheus Lab’ys, Inc., 566 U.S.
 66, 70 (2012)).
     The proper § 101 analysis was described by the Su-
 preme Court in Alice and Mayo. At step one of the Al-
 ice/Mayo test, we determine whether the claims are
 directed to a law of nature, natural phenomenon, or an
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 14                      PURECIRCLE USA INC. v. SWEEGEN, INC.

 abstract idea. Alice Corp. Pty. v. CLS Bank Int’l, 573 U.S.
 208, 217 (2014) (citing Mayo, 566 U.S. at 77). If the claims
 are so directed, we then at step two determine if the claims
 embody an “inventive concept,” meaning “an element or
 combination of elements that is ‘sufficient to ensure that
 the patent in practice amounts to significantly more than
 a patent upon the [ineligible concept] itself.’” Id. at 217–18
 (alteration in original) (quoting Mayo, 566 U.S. at 72–73).
     To the extent that claim 14 claims a “method for mak-
 ing Rebaudioside X comprising a step of converting Rebau-
 dioside D to Rebaudioside X using a UDP-
 glucosyltransferase,” it claims a natural phenomenon. The
 enzyme in claim 14, UGT76G1, is naturally found in stevia
 plants and naturally converts Reb D to Reb X. If that were
 the extent of claim 14, it would clearly claim an unpatent-
 able natural phenomenon. As the district court noted
 “there is no dispute that the conversion of steviol glycosides
 and Reb D to Reb [X] using UGT enzymes is a natural pro-
 cess.” J.A. 10.
     PureCircle argues that the outcome should be different
 because in nature only small amounts of Reb X are pro-
 duced, whereas claim 1 (from which claim 14 depends) pro-
 vides “conversion of Rebaudioside D to Rebaudioside X is
 at least about 50% complete.” ’273 patent, col. 35, ll. 4–5.
 PureCircle contends that because the conversion of Reb D
 to Reb X would never reach 50% completion in nature,
 claim 14 is not directed to a natural phenomenon. The
 problem with PureCircle’s argument is that the 50% com-
 pletion is itself an abstract idea.
     To be eligible under § 101, an invention must have the
 “specificity required to transform a claim from one claiming
 only a result to one claiming a way of achieving it.” SAP
 Am., Inc. v. InvestPic, LLC, 898 F.3d 1161, 1167 (Fed Cir.
 2018). “[I]n the context of claims to results, we have ex-
 plained that claims that ‘simply demand[] the production
 of a desired result . . . without any limitation on how to
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 PURECIRCLE USA INC. v. SWEEGEN, INC.                       15

 produce that result’ are directed to an abstract idea.” In re
 Killian, 45 F.4th 1373, 1382 (Fed. Cir. 2022) (quoting In-
 terval Licensing LLC v. AOL, Inc., 896 F.3d 1335, 1345
 (Fed. Cir. 2018)); see also Am. Axle & Mfg., Inc. v. Neapco
 Holdings LLC, 967 F.3d 1285, 1292 (Fed. Cir. 2020) (“[T]o
 avoid ineligibility, a claim must ‘ha[ve] the specificity re-
 quired to transform [the] claim from one claiming only a
 result to one claiming a way of achieving it.’”). As the dis-
 trict court explained, claim 14 of the ’273 patent “d[id] not
 specify how to achieve a particular purity or conversion
 percentage; rather, [it] only recite[s] the resulting percent-
 ages.” J.A. 12. Claim 14 simply states a result, conversion
 of Reb D to Reb X wherein the conversion is at least about
 50% complete. The claim does not provide any steps or give
 guidance as to how to achieve a 50% conversion other than
 the direction to use a natural enzyme. Claim 14 is directed
 to subject matter that is a natural phenomenon or abstract
 idea at step 1 of Alice/Mayo. 11

     11  PureCircle points to Natural Alternatives, where
 the patent claimed a “method of increasing anaerobic work-
 ing capacity in a human subject” through “elevat[ing] beta-
 alanine above natural levels to cause an increase in the
 synthesis of beta-alanylhistidine dipeptide in the tissue.”
 918 F.3d 1338, 1343–44 (Fed. Cir. 2019) (citation omitted).
 While the claims in Natural Alternatives similarly claimed
 a compound which existed in nature in quantities higher
 than natural levels, we explained that the method of appli-
 cation involved the method of affirmatively treating pa-
 tients with quantities that did not exist in nature, thereby
 altering an individual’s natural state. Id. at 1344; see also
 id. at 1346 (holding that the “treatment claims . . . cover
 using a natural product in unnatural quantities to alter a
 patient’s natural state, to treat a patient with specific dos-
 ages outlined in the patents”). Claim 14, by contrast, is not
Case: 22-1946    Document: 48     Page: 16   Filed: 01/02/2024

 16                     PURECIRCLE USA INC. v. SWEEGEN, INC.

     PureCircle made no step two Alice/Mayo arguments be-
 fore us or the district court. Claim 14 is therefore invalid
 as directed to unpatentable subject matter.
                        CONCLUSION
     We affirm the district court’s grant of summary judg-
 ment that claims 1–13 of the ’273 patent and claims 1–7 of
 the ’257 patent are invalid for lack of written description,
 and that claim 14 of the ’273 patent is unpatentable under
 35 U.S.C. § 101.
                        AFFIRMED

 a treatment claim. Thus, reliance on Natural Alternatives
 is misplaced.