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Another Genus Claim Bites the Dust for Lack of Written Description

Addressing the issue of written description in the context of antibody-related genus claims, the US Court of Appeals for the Federal Circuit reversed a $1.2 billion jury verdict and found genus claims using functional language invalid for lack of written description. Juno Therapeutics, Inc. v. Kite Pharma, Inc., Case No. 20-1758 (Fed. Cir. Aug. 26, 2021) (Moore, J.)

Kite’s YESCARTA® is a therapy in which a patient’s T cells are engineered to express a chimeric antigen receptor (CAR) to target the antigen CD19. Juno sued Kite, alleging infringement of a patent relating to a nucleic acid polymer encoding a three-part CAR for a T cell. The three-part CAR comprises:

  1. An intracellular domain of the CD3 ζ (zeta) chain, a signaling domain that is activated to create an initial immune response
  2. A costimulatory region comprising of a specific amino acid sequence (here, a specific CD28 sequence) that, when activated, directs the T cells to multiply
  3. A binding element that determines what target molecule or antigen the CAR can bind to, such as a single-chain antibody variable fragment (scFV).

Juno’s patent disclosed two scFVs (one that binds CD19 and another that binds PSMA) but did not disclose the amino acid sequence of either scFV.

After a two-week trial, the jury reached a verdict in Juno’s favor, finding in relevant part that Kite failed to prove that any of the asserted claims were invalid for lack of written description or enablement. The jury awarded damages amounting to a $585 million upfront payment and an almost 28% running royalty. The district court denied Kite’s motions for judgment as a matter of law and enhanced the total award to approximately $1.2 billion in addition to the 28% running royalty. Kite appealed.

The Federal Circuit reversed, concluding that no reasonable jury could find adequate written description because the patent disclosed neither representative species nor common structural features of the claimed scFV genus to identify which of the millions of billions of scFVs would function as claimed. Turning first to lack of representative species, the Court explained that the broadest asserted claims cover any scFV that binds to any target of clinical interest but fails to provide a representative sample of species within, or defining characteristics for, that expansive genus. The Court also disagreed that the two working embodiments in the patent were representative of the entire genus of vast number of possible scFVs that bind to an undetermined number of targets without more in the disclosure (such as the characteristics of the exemplary scFVs that allow them to bind to particular targets or nucleotide sequences). The Court stated that even if such scFVs were known as Juno argued, the specification provided no means of distinguishing which scFVs would bind to which targets.

Turning next to lack of structural features common to the claimed genus, the Federal Circuit held that general assertions that scFVs generally have a common structure in the context of the technology in this case were insufficient because an scFV with the [...]

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Knowledge of Patent, Evidence of Infringement Are Necessary, but Not Sufficient, to Establish Willfulness

Addressing claim construction, enablement, damages and willfulness, the US Court of Appeals for the Federal Circuit found that evidence of a defendant’s knowledge of the asserted patent and proof of infringement were, by themselves, legally insufficient to support a finding of willfulness. Bayer Healthcare LLC v. Baxalta Inc., Case No. 19-2418 (Fed. Cir. Mar. 1, 2021) (Stoll, J.)

Bayer owns a patent on certain recombinant forms of human factor VII (FVIII), a protein that is critical for blood coagulation. Recombinant FVIII is useful as a treatment for coagulation disorders, primarily Hemophilia A. Natural FVIII has a short half-life, making therapeutic administration expensive and inconvenient. Adding polyethylene glycol (a process known as PEGylating) to FVIII at random sites was found to increase the protein’s half-life but reduce its function. Bayer invented FVIII that is PEGylated in a specific region (the B-domain) so that it retains its function and maintains the longer half-life.

After Baxalta developed a PEGylated FVIII therapeutic, Adynovate®, Bayer sued Baxalta for infringement of its patent. During claim construction, the district court construed the claim preamble “an isolated polypeptide conjugate” to mean “a polypeptide conjugate where conjugation was not random,” finding that Bayer had disclaimed conjugates with random PEGylation. The district court also construed “at the B-domain” to mean “attachment at the B-domain such that the resulting conjugate retains functional FVIII activity,” rejecting Baxalta’s proposal of “at a site that is not any amine or carboxy site in FVIII and is in the B-domain” because Bayer had not disclaimed PEGylation at amine or carboxy sites. Before trial, Baxalta moved for clarification of the term “random” in the construction of the preamble, but the district court “again” rejected Baxalta’s argument that Bayer defined “random” conjugation as “any conjugation at amines or carboxy sites.”

Before trial, Baxalta moved to exclude the testimony of Bayer’s damages expert regarding his proposed reasonable-royalty rate. The expert had defined a bargaining range and proposed to testify that the royalty rate should be the midpoint of the range based on the Nash Bargaining Solution. The district court permitted the expert to testify as to the bargaining range but excluded the opinions regarding the midpoint as insufficiently tied to the facts of the case.

After trial, the district court granted Baxalta’s pre-verdict motion for judgment as a matter of law (JMOL) of no willful infringement. Subsequently, the jury returned a verdict that the claims were infringed and not invalid for non-enablement, and awarded damages based on an approximately 18% royalty rate for the period for which the parties had presented sales information. Baxalta moved for JMOL or a new trial on infringement, enablement and damages. Bayer moved for pre-verdict supplemental damages for the period between the presented sales data and the date of judgment, and for a new trial on the issue of willfulness. The district court denied all of Baxalta’s motions and Bayer’s motion for new trial, but granted Bayer’s motion for supplemental damages, applying the jury’s ~18% rate to sales data for the later period. [...]

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