In re: Xencor, Inc., Appeal No. 2024-1870 (Fed. Cir. Mar. 13, 2025)
Our case of the week is an appeal from a decision of the Appeals Review Panel of the Patent Trial and Appeal Board, concerning Xencor’s patent application titled “Fc Variants with Altered Binding to FcRn.” The application, filed in 2020, asserts that “modifying antibodies with certain amino acid substitutions provides for longer staying power in the body and reduces the need for more frequent treatment.” The panel agreed with the board that the limiting preambles of the Jepson claims at issue were not supported by sufficient written description in the specification, and the Federal Circuit affirmed.
The Court first analyzed the method claim at issue and decided whether the phrases “treating a patient” and “administering” in the preamble were limiting. Xencor argued that different sections of a preamble may be considered independently, and only the sections the claims rely on or are necessary to give “life, meaning, and vitality” is limiting. The Court, however, found that the instant preamble “cannot be neatly packaged into two separate portions” because “treating a patient” was connected to “administering” with the word “by.” Furthermore, “treating a patient” gave color and meaning to “administering” because the claim had no specific dosage and rate; thus, a person of ordinary skill in the art would have to read “increased in vivo half-life,” a limitation in the claim, in light of “treating a patient” to make sense of the scope of the claim. Therefore, the preamble was limiting as a whole.
After specific analysis of the preamble language, the Court found that Xencor had not demonstrated sufficient written description for the method claimed, because the specification included no examples that related to the limitation in the preamble. For example, the specification did not describe “what patients with what diseases or conditions can be successfully treated with an anti-C5 antibody possessing the claimed Fc modifications.” The Court noted that there was no requirement to show the method was effective; only that the applicant had possession of the method.
The Court then turned to the question of whether the preamble of a Jepson claim requires written description support at all. Pursuant to 35 U.S.C. § 112, a specification must “contain a written description of the invention . . . , in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same.” The Court explained that a Jepson claim is a type of claim wherein “a patentee uses the preamble to recite ‘elements or steps of the claimed invention which are conventional and known’ (37. C.F.R. §1.75(3) (1996)” such that a Jepson claim uses a preamble to describe the prior art and “limit[] the claim scope.”
Xencor argued that, because the “invention” in a Jepson claim is the improvement over the prior art, it needs only to have written description to support that improvement. However, the Court reasoned that when a claim is written as a Jepson claim, the invention is “not only the claimed improvement, but the claimed improvement as applied to the prior art, so the inventor must provide written description sufficient to show possession of the claimed improvement to what was known in the prior art” (emphasis in the original). This means the invention is the totality of the claim, including the preamble. As such, “its totality is what must have written description support….” The Court reasoned that to hold otherwise would be effectively “doing away” with the written description requirement, and that inventors would be able “improperly, to obtain a patent on something [the inventor] does not actually possess.”
The Court went on to explain “the applicant must establish that what is claimed to be well-known in the prior art is, in fact, well-known in the prior art.” The Court concluded that Xencor had not provided sufficient written description in support of the Jepson claim, because Xencor failed to establish that anti-C5 antibodies were well-known in the art.
The full opinion can be found here.
By Jeff Liao
ALSO THIS WEEK
Merck Sharp & Dohme BV et al. v. Aurobindo Pharma USA, Inc., Appeal No. 2023-2254 (Fed. Cir. March 13, 2025)
In an appeal from the United States District Court for the District of New Jersey, the Federal Circuit affirmed. The Court held that, at least for reissued patents where the original patent was directed to a drug product subject to FDA review, “the patent” in 35 U.S.C. § 156(c) used to determine the length of patent term extensions (“PTE”) refers to the original patent. Because the term “the patent” in § 156(c) was ambiguous, the Federal Circuit considered the context of the Hatch-Waxman Act to define it. According to the Federal Circuit, the purpose of PTEs under § 156(c) was clearly “to compensate pharmaceutical companies for the effective truncation of their patent terms while waiting for regulatory approval of new drug applications.” Because the regulatory review period after the reissue would be shorter than the regulatory review period following issue of the original patent (which review period would include the regulatory review period after the reissue as well), in the case of reissued patents where the original patent was directed to a drug product subject to FDA review, companies could only be truly compensated if the PTE was based off the regulatory review period for the original patent. Therefore, use of “the patent” to calculate the PTE for a reissue must refer to the original patent. In a footnote, the Federal Circuit explained that its holding did not address how to calculate the PTE of a reissued patent when only the reissued patent, and not the original patent, was directed to a drug product.
The full text of the opinion is available here.
By Tyler Hall
Regeneron Pharms., Inc. v. Amgen Inc., Appeal No. 2024-2351 (Fed. Cir. Mar. 14, 2025)
In an appeal from a district court’s denial of a motion for a preliminary injunction, the Federal Circuit affirmed. The district court found that Regeneron had not established a likelihood of success on its claim that Amgen had infringed a Regeneron patent that covered its EYLEA® biologic treatment for angiogenic eye disorders. At issue on appeal was whether the claims’ recitation of “a vascular endothelial growth factor (VEGF) antagonist” and “a buffer” were properly construed to refer to distinct components, since Amgen’s accused formulation had used a self-buffering VEGF instead of a separate buffer component. The Federal Circuit found that the district court had properly applied the presumption—provided for in Becton, Dickenson & Co. v. Tyco Healthcare Grp., LP, 616 F.3d 1249 (Fed. Cir. 2010)—that a claim’s separate listing of elements presents a “clear implication” that they refer to distinct components of the invention. The Court rejected Regeneron’s argument that this presumption was either inapplicable or overcome, because the patents’ claims and specification reinforced the presumption of separateness, and that the extrinsic evidence presented was insufficient to rebut it. Because Amgen had raised a substantial question of non-infringement, the Court affirmed the denial of a preliminary injunction.
The opinion can be found here.
By Jason A. Wrubleski
CQV Co., Ltd. V. Merck Patent GmbH, Appeal No. 2023-1027 (Fed. Cir. Mar. 10, 2025)
In an appeal from a final written decision regarding a post-grant review, the Federal Circuit remanded for further consideration of additional evidence related to potential prior art. The patent concerned alumina flakes used as luster in paints, printing ink, and other products. At issue was whether a particular batch of alumina flakes qualified as prior art—whether it had been on sale prior to the relevant priority date. The Board dismissed it as prior art. But the Court held the Board had erred by failing to consider certain evidence of record which suggested “Sample C would have been made available to the public within a few weeks of being placed into quality control, which the Board discarded without explanation.” The Court vacated and remanded for further consideration of the additional evidence. The Court also found that CQV had standing to appeal the Board’s decision because CQV was obligated to indemnify a customer for infringement liability as to the alumina flakes that Merck alleged infringed its patent.
The opinion can be found here.
By Nika Aldrich
Sierra Wireless, ULC v. Sisvel S.P.A., Appeal Nos. 2023-1059, -1085, -1089, 1125 (Fed. Cir. Mar. 10, 2025)
In appeal from a final written decision of the Patent Trial and Appeal Board, the Federal Circuit vacated the Board’s finding that certain claims of Sisvel’s U.S. Patent No. 7,869,396 were unpatentable as obvious, and remanded for further consideration. The patent concerned data transmission methods to reduce data loss in wireless communication systems, and claimed method steps which included stopping a timer under certain conditions, and taking certain actions when the timer expired. At issue was whether these limitations were “conditional,” and whether the Board’s finding that one of those limitations was disclosed in the prior art was supported by substantial evidence.
The Federal Circuit found the Board had erroneously construed the timer limitations as conditional, because the plain and unambiguous language of claim 1 required that both limitations be performed whenever their preconditions applied. In addition, the Court agreed with Sisvel that a Board finding—that one of the limitations was disclosed in the prior art—was not supported by substantial evidence. The Court further held the Board had abused its discretion by relying on the expert testimony of Sisvel’s expert without determining whether he qualified as a skilled artisan.
The opinion can be found here.
By Brittani Gambrell
