DCT

1:19-cv-01193

Kite Pharma Inc v. Cabaret Biotech Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-01193, E.D. Va., 09/16/2019
  • Venue Allegations: Plaintiffs allege venue is proper under 35 U.S.C. § 293 because Defendant is a foreign patentee that has not designated an agent for service of process in the United States.
  • Core Dispute: Plaintiffs, licensees of the patent-in-suit, seek a declaratory judgment that the patent, which relates to Chimeric Antigen Receptor (CAR) technology, is invalid and not infringed by their YESCARTA® cancer therapy.
  • Technical Context: The technology involves genetically engineering a patient's own T-cells to recognize and attack cancer cells, a field known as CAR-T therapy, which represents a significant advancement in oncology.
  • Key Procedural History: The parties executed a license agreement for the patent-in-suit in 2013. Plaintiffs allege they are paying royalties under protest and have a reasonable apprehension of being sued for infringement if they terminate the agreement, based on alleged threats from the Defendant. The patent underwent ex parte reexamination, with a certificate issuing in 2017 that included amended claims.

Case Timeline

Date Event
1992-03-18 Earliest Priority Date for '465 Patent
2010-06-22 U.S. Patent No. 7,741,465 Issues
2011-01-01 (approx.) Discussions begin between Kite and inventor Dr. Eshhar
2013-01-01 (approx.) Cabaret Biotech Ltd. is formed
2013-12-12 (approx.) License agreement executed between Kite and Cabaret
2017-08-29 Reexamination Certificate for '465 Patent Issues
2017-10-18 YESCARTA® receives FDA approval
2017-10-01 (approx.) First sales of YESCARTA® begin
2019-09-16 Complaint for Declaratory Judgment Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,741,465 - Chimeric receptor genes and cells transformed therewith

  • Patent Identification: U.S. Patent No. 7,741,465, issued June 22, 2010.

The Invention Explained

  • Problem Addressed: The patent describes limitations in prior cancer immunotherapies. The effectiveness of T-cells is restricted by the need to recognize antigens presented by the major histocompatibility complex (MHC), while the therapeutic use of antibodies is hindered by their poor ability to access solid tumors and recruit the immune system. (’465 Patent, col. 1:21-39, col. 2:50-65).
  • The Patented Solution: The invention proposes a chimeric receptor gene that fuses two key components into a single protein. It combines the targeting portion of an antibody—a single-chain variable fragment (scFv)—with the signaling machinery of an immune cell receptor, such as the zeta or gamma chains of the T-cell receptor. (’465 Patent, Abstract; col. 4:26-45). When this gene is introduced into a lymphocyte (e.g., a T-cell), the cell is endowed with an antibody's targeting specificity but retains its own potent effector functions, all without MHC restriction. (’465 Patent, col. 3:11-45).
  • Technical Importance: This technology provides a method to redirect the powerful cell-killing and signaling capabilities of lymphocytes toward virtually any target for which an antibody can be made, forming a foundational principle of modern CAR-T cell therapies. (’465 Patent, col. 11:45-50).

Key Claims at a Glance

  • The complaint’s invalidity arguments focus on language found in independent claims 21 and 30, which were added during reexamination. (Compl. ¶25).
  • Independent Claim 21:
    • A chimeric DNA comprising:
    • a first DNA segment encoding a single-chain Fv domain (scFv) ... by a flexible linker, and
    • a second DNA segment encoding partially or entirely the transmembrane and cytoplasmic, and optionally the extracellular, domains of an endogenous protein,
    • wherein said endogenous protein is CD28,
    • which chimeric DNA, upon transfection to lymphocytes, expresses both said scFv domain and said domains of said endogenous protein in one single, continuous chain on the surface of the transfected lymphocytes,
    • such that the transfected lymphocytes are triggered to activate and/or proliferate and have MHC non-restricted antibody-type specificity when said expressed scFv domain binds to its antigen.
  • Independent Claim 30:
    • Structurally identical to claim 21, except the endogenous protein is specified as CD8.
  • The complaint makes broad allegations against all claims of the '465 patent and implicitly reserves the right to challenge any claim. (Compl. ¶23).

III. The Accused Instrumentality

Product Identification

  • YESCARTA® (axicabtagene ciloleucel). (Compl. ¶11).

Functionality and Market Context

  • YESCARTA® is described as a CAR-T therapy that involves genetically engineering a patient's own T-cells to recognize and target the CD19 antigen, a protein found on the surface of certain leukemia and lymphoma cells. (Compl. ¶11).
  • The complaint characterizes the therapy as "revolutionary" and part of an "industry-leading pipeline," noting its FDA approval for treating specific forms of large B-cell lymphoma. (Compl. ¶¶10-12).

IV. Analysis of Infringement Allegations

The complaint seeks a declaratory judgment of non-infringement but does not provide a detailed infringement analysis or claim chart. Instead, its primary assertions relate to the invalidity of the '465 patent, from which it concludes that its YESCARTA® product cannot infringe a valid claim. (Compl. ¶¶33-35). The core of the plaintiffs' case as presented in the complaint rests on the following invalidity arguments:

  • Lack of Written Description and Enablement (35 U.S.C. § 112): The complaint alleges that the patent specification fails to adequately describe and enable the full scope of the claimed invention. (Compl. ¶24). It argues that the claim language "encoding partially or entirely ... and optionally" the domains of CD28 or CD8 covers a "vast number of potential combinations" for which the specification provides insufficient guidance or support, and that determining which combinations would be functional would require undue experimentation. (Compl. ¶26).
  • Indefiniteness (35 U.S.C. § 112): The complaint alleges the claims are indefinite for failing to distinctly claim the invention. (Compl. ¶24). It specifically attacks the limitation requiring that the chimeric DNA "expresses both said scFv domain and said domains of said endogenous protein in one single, continuous chain on the surface of the transfected lymphocytes." (Compl. ¶29). Plaintiffs contend this language literally requires cytoplasmic domains to be on the cell surface, rendering the claims inoperable and indefinite. (Compl. ¶29).
  • Obviousness (35 U.S.C. § 103): The complaint raises a conditional argument that, to the extent the patentee argues the broad claims are supported by the specification, the claims would have been obvious over the prior art. (Compl. ¶30).
  • No probative visual evidence provided in complaint.

V. Key Claim Terms for Construction

  • The Term: "encoding partially or entirely the transmembrane and cytoplasmic, and optionally the extracellular, domains"

    • Context and Importance: This phrase is central to the plaintiffs' written description and enablement challenge. The interpretation of "partially" and "optionally" will determine the breadth of the claimed genus and whether the specification provides commensurate support for all potential protein constructs covered by the claims. (Compl. ¶26).
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent describes the invention in general terms as fusing an scFv to a "lymphocyte-triggering molecule," which may suggest the specific length or inclusion of all domains is not critical to the core inventive concept. (’465 Patent, col. 4:50-54).
      • Evidence for a Narrower Interpretation: A court may look to the specific embodiments and figures, which depict particular constructs. If these examples only show full-length domains, it could support an argument that "partially" lacks adequate description. (’465 Patent, e.g., FIG. 1, FIG. 19).

  • The Term: "on the surface of the transfected lymphocytes"

    • Context and Importance: Plaintiffs' indefiniteness argument hinges on a literal interpretation of this term, alleging it nonsensically requires intracellular protein domains to be located outside the cell. (Compl. ¶29). The construction of this term may determine the viability of that invalidity theory.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader (Functional) Interpretation: A defendant would likely argue that, in the context of transmembrane proteins, "on the surface" is understood by a person of ordinary skill to mean the protein is properly embedded in the cell membrane and presented on the surface, not that every component is physically located on the exterior. The patent's figures depicting the chimeric receptor spanning the cell membrane may support this functional interpretation. (’465 Patent, FIG. 1, FIG. 13).
      • Evidence for a Narrower (Literal) Interpretation: The plaintiffs' argument relies on the plain language of the claim. While this interpretation appears technically strained, claim construction focuses on the words of the claim itself, and this phrasing creates a potential ambiguity for a court to resolve.

VI. Other Allegations

  • Indirect Infringement: The complaint makes a blanket denial of any direct or indirect infringement but provides no specific facts to rebut allegations of inducement or contributory infringement beyond its primary argument that the patent is invalid. (Compl. ¶34).
  • Willful Infringement: This is not alleged, as the action is a declaratory judgment of non-infringement brought by the accused infringer.

VII. Analyst’s Conclusion: Key Questions for the Case

  • A central issue will be one of validity under 35 U.S.C. § 112: Does the specification provide sufficient written description and enablement for the full, broad scope of the claimed genus, particularly for the vast number of constructs encompassed by the terms "partially," "entirely," and "optionally" as applied to the domains of CD28 and CD8?
  • A key question of claim construction will be whether the phrase requiring the chimeric protein to be expressed "on the surface" is interpreted functionally, as is common for transmembrane proteins, or if its literal wording renders the claims indefinite, as the plaintiffs allege.
  • A threshold jurisdictional question may arise regarding whether an "actual controversy" exists sufficient to support a declaratory judgment action, turning on whether the plaintiffs' status as a licensee paying royalties "under protest" and its allegations of threats from the defendant create a legally sufficient "reasonable apprehension" of an impending infringement suit.