DC decision finding Juno’s CAR-T claims to be properly described reversed

Juno Therapeutics, Inc., Sloan Kettering v. Kite Pharma, Inc.

Docket No. 2020-1758 (http://www.cafc.uscourts.gov/sites/default/files/opinions-orders/20-1758.OPINION.8-26-2021_1825257.pdf)


August 26, 2021

Brief Summary:  DC decision that Juno’s claimed “binding element that specifically interacts with a selected target” (e.g., scFv that binds CD19) was properly described reversed.

Summary:  Kite appealed DC decision finding Juno’s US 7,446,190 directed to nucleic acids encoding chimeric T cell receptors (chimeric antigen receptors, CARs) not invalid for lack of written description, the certificate of correction is not invalid, and awarding Juno over $1.2 billion in damages for infringement by Kite’s YESCARTA® product.  The FC panel found the claims invalid for lacking a proper written description (WD; under pre-AIA section 112) and reversed the DC’s decision without reaching the other issues.  Independent claim 1 of the ‘190 patent claims “a nucleic acid polymer encoding” a CAR “comprising…a zeta chain portion…a costimulatory signaling region [SEQ ID NO:6]…and…a binding element that specifically interacts with a selected target” and dependent claims 3 and 9 limiting “the claimed ‘binding element’ to ‘a single chain antibody,’ i.e., an scFv.”  Kite’s product includes “an scFv that binds the CD19 antigen”.  The FC panel explained the basic WD requirements (“reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date” (Ariad, FC 2010), not a “mere wish or plan” (Centocor, FC 2011)) and that those vary “with the nature and scope of the invention at issue, and with the scientific and technologic knowledge already in existence” (Capon, FC 2005).  Further, the FC panel explained, “[f]or genus claims using functional language, like the binding function of the scFvs claimed here, the written description ‘must demonstrate that the applicant has made a generic invention that achieves the claimed result and do so by showing that the applicant has invented species sufficient to support a claim to the functionally-defined genus’” (“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)) and that “a description of a chemical species, ‘requires a precise definition, such as by structure, formula, [or] chemical name,’ of the claimed subject matter sufficient to distinguish it from other materials” (Lilly, 1997).  Here, the FC panel found that the ‘190 patent explains that “[t]he target” of the scFV “can be any target of clinical interest to which it would be desirable to induce a T cell response” (in the FC panel’s words “any scFv for binding any target”) and that the ‘190 WD “fails to provide a representative sample of species within, or defining characteristics for, that expansive genus” and “no details about these scFv species beyond the alphanumeric designations J591 and SJ25C1 for a skilled artisan to determine how or whether they are representative of the entire claimed genus.”  The FC panel wrote that “[t]o satisfy the written description requirement, the patent needed to demonstrate to a skilled artisan that the inventors possessed and disclosed in their filing the particular species of scFvs that would bind to a representative number of targets”, which is not satisfied by “[t]he disclosure of one scFv that binds to CD19 and one scFv that binds to a PSMA antigen on prostate cancer cells”.   The FC panel added that it is not saying “that a patentee must in all circumstances disclose the nucleotide or amino acid sequence of the claimed scFvs to satisfy the written description requirement when such sequences are already known in the prior art” and that “[i]t is not fatal that the amino acid sequences of these two scFvs were not disclosed as long as the patent provided other means of identifying which scFvs would bind to which targets, such as common structural characteristics or shared traits.”  Juno argued “that because scFvs, in general, were known, the two scFvs in the ’190 patent are representative” but the FC panel responded that “the specification provides no means of distinguishing which scFvs will bind to which targets” (citing Lilly and distinguishing Capon in which “more was known in the prior art”; see FN2:  “We agree with Juno that a patent specification need not redescribe known prior art concepts.”  Immunex, FC 2020).  The FC panel also found Juno’s expert testimony insufficient even though “[i]t is undisputed that scFvs generally have a common structure” given that “an scFv with the same general common structure but with a different amino acid sequence would recognize a different antigen” (citing Idenix, FC 2019 (“the patent merely provided ‘lists or examples of supposedly effective nucleosides, but [did] not explain what makes them effective, or why’”) and Abbvie, FC 2014 (“the patents described one species of structurally similar antibodies derived from only one lead antibody”); distinguishing Erfindergemeinschaft, FC 2018 (“there were hundreds of known PDE5 inhibitors, the type of compound at issue, and the patent identified the compounds by chemical name and structural drawings”)).  Claims 5 and 11, “limited to scFvs that bind CD19 (a specific target)”, were also found to lack WD even though Kite itself argued “that there were ‘four or five’ CD19-specific scFvs ‘arguably known in the art’ at the priority date” (including as argued by Juno “the one used in YESCARTA®”).  Thus, the FC panel reversed the DC decision.

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