PureCircle USA Inc. et al. v. Sweegen, Inc. et al.
Docket No. 2022-1946 (https://cafc.uscourts.gov/opinions-orders/22-1946.OPINION.1-2-2024_2246968.pdf) (Non-precedential)
DYK, SCHALL, STARK
January 2, 2024
Brief Summary: DC finding of no WD of genus of enzymes used in method and claim to specific enzyme unpatentable under 101 as it is naturally occurring and specificity limitation is an abstract idea (e.g., “simply states a result”). Summary: PureCircle appealed DC grant of summary judgment (SJ) to Sweegen, concluding the asserted claims of US 9,243,273 and 10,485,257 are invalid for lack of written description and/or unpatentable under 35 U.S.C. § 101. The ‘273 and ‘257 patents relate to methods for making Rebaudioside X, a steviol glycoside found in trace amounts in stevia plants, “wherein the conversion of Rebaudioside D to Rebaudioside X is at least about 50% complete.” The FC panel opinion explains that “[b]ecause only small amounts of Reb X naturally occur in stevia plants, it would be expensive and inefficient to extract Reb X from the plants”, and the disputed patents “claim a method of producing Reb X using enzymes called UDPglucosyltransferases (‘UGTs’), the same enzymes used in plants to synthesize the compound”. In front of the DC, “[t]he 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 steviol glycoside molecule’”, the DC concluding that “based on the parties’ stipulation, the term was functionally defined.” The FC panel reviewed the DC decision de novo, and explained that SJ “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 adverse party, the movant is clearly entitled to prevail as a matter of law” (Clarkson, 9th Cir. 2023). On written description, the FC panel explained that “[i]n the context of a genus claim, written description “requires 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, FC 2010; Novozymes, FC 2013 (“sufficient ‘blaze marks’”)) and “[t]he claims of the ’273 and ’257 patents are properly construed as genus claims using functional language” (“claim a genus of UGT enzymes” defined “by what it does”). SweeGen argued a representative number of species, nor common structural features, were not disclosed “to identify which enzymes would function to convert Reb D to Reb X at a 50% completion level or higher”. Pure Circle argued only five such enzymes were known and mutants could easily be tested (“routine” (Invitrogen, FC 2005; Bilstad, FC 2004) but see LizardTech; Juno, FC 2021 (scFVs); In re Alonso, FC 2008 (hybridomas); Univ. Rochester, FC 2004 (trial and error); AbbVie, FC 2014 (antibodies); Idenix, FC 2019; Enzo, FC 2002)). The FC panel found no error with the DC decision (e.g., “In short, the one enzyme disclosed in the patents here has not been shown to be typical of the entire genus of UGTs claimed.”) While claim 14 names a specific enzyme (UGT76G1), the FC panel did not consider it with respect to WD because it found the claim unpatentable under § 101. The FC panel explained that claim 14 “claims a natural phenomenon” as UGT76G1 “is naturally found in stevia plants and naturally converts Reb D to Reb X.” The FC panel also found the “50% completion” limitation to be “an abstract idea” as it “d[id] not specify how to achieve a particular purity or conversion percentage; rather, [it] only recite[s] the resulting percentages” and “simply states a result” (SAP, FC 2018; In re Killian, FC 2022; Am. Axle, FC 2020). The FC panel therefore concluded claim 14 is “invalid as directed to unpatentable subject matter.” The DC decision was therefore affirmed.