DCT

1:23-cv-00548

Acerta Pharma BV v. Alembic Pharma Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:23-cv-00548, D. Del., 05/19/2023
  • Venue Allegations: Venue is alleged to be proper as to Alembic Pharmaceuticals, Inc. because it is a Delaware corporation that resides in the district, and as to Alembic Pharmaceuticals Limited because it is a foreign corporation subject to personal jurisdiction in the district.
  • Core Dispute: Plaintiffs allege that Defendants’ submission of an Abbreviated New Drug Application (ANDA) for a generic version of the cancer drug CALQUENCE® constitutes an act of infringement of a patent covering a method of treating mantle cell lymphoma.
  • Technical Context: The technology at issue involves specific dosing regimens for Bruton's tyrosine kinase (BTK) inhibitors, a class of small-molecule drugs used to treat certain B-cell cancers like lymphomas and leukemias.
  • Key Procedural History: The complaint notes that the asserted patent was previously part of a separate lawsuit between the parties (C.A. No. 22-154-GBW-SRF). In that prior action, Plaintiffs’ claims regarding the patent were dismissed without prejudice after Alembic certified it did not intend to seek FDA approval before the patent’s expiration. Alembic subsequently notified Plaintiffs that it had changed its certification and now seeks approval prior to expiration, which precipitated the filing of this new complaint.

Case Timeline

Date Event
2014-01-21 '083 Patent Priority Date
2019-04-30 '083 Patent Issue Date
2021-12-28 Alembic's First Notice Letter regarding related patents
2022-02-02 Prior litigation filed by Plaintiffs against Alembic
2022-03-25 '083 patent claims dismissed without prejudice in prior litigation
2023-04-05 Alembic's Second Notice Letter regarding '083 patent
2023-05-19 Complaint Filing Date

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

U.S. Patent No. 10,272,083 - "Methods of Treating Chronic Lymphocytic Leukemia and Small Lymphocytic Leukemia Using a BTK Inhibitor"

  • Patent Identification: U.S. Patent No. 10,272,083, "Methods of Treating Chronic Lymphocytic Leukemia and Small Lymphocytic Leukemia Using a BTK Inhibitor," issued April 30, 2019.

The Invention Explained

  • Problem Addressed: The patent's background section describes a significant need for less toxic and more effective treatments for B-cell malignancies like chronic lymphocytic leukemia (CLL) and small lymphocytic leukemia (SLL), noting that many standard therapies are associated with toxicities and immunosuppression ('083 Patent, col. 1:41-49).
  • The Patented Solution: The invention provides therapeutic methods for treating various hematological malignancies by orally administering a specific BTK inhibitor, identified as the compound of Formula (II) (acalabrutinib), at particular dosages ('083 Patent, Abstract; col. 2:10-18). The patent claims specific methods of using this compound for treating different cancers, including mantle cell lymphoma, at defined doses ('083 Patent, col. 100:40-51).
  • Technical Importance: The invention claims a specific method of use for a targeted therapy, which represents a shift away from broader chemotherapies toward more precise mechanisms of action intended to improve efficacy and reduce toxicity ('083 Patent, col. 1:41-49).

Key Claims at a Glance

  • The complaint asserts independent claim 8 ('083 Patent, col. 100:40-51; Compl. ¶36).
  • The essential elements of independent claim 8 are:
    • A method of treating a mantle cell lymphoma (MCL) in a human subject suffering therefrom
    • comprising the step of orally administering, to the human subject,
    • a dose of 100 mg twice daily of a Bruton's tyrosine kinase (BTK) inhibitor,
    • wherein the BTK inhibitor is a compound of Formula (II) or a pharmaceutically-acceptable salt, hydrate, or solvate thereof.
  • The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is Alembic's ANDA Product, which is the subject of ANDA No. 216775 submitted to the FDA (Compl. ¶1).

Functionality and Market Context

  • The complaint alleges that Alembic's ANDA Product is a generic version of Plaintiffs' CALQUENCE® product, which contains acalabrutinib as its active ingredient (Compl. ¶¶ 24-25). The ANDA seeks approval for a 100 mg oral capsule of acalabrutinib (Compl. ¶31).
  • The infringement is the statutory act of submitting the ANDA to obtain approval to manufacture and sell the generic product for infringing uses prior to the expiration of the '083 Patent (Compl. ¶¶ 1, 38). The complaint alleges that the proposed labeling for Alembic's ANDA Product will direct its use in an infringing manner (Compl. ¶41). CALQUENCE® is indicated for the treatment of adult patients with mantle cell lymphoma (MCL) (Compl. ¶24).

IV. Analysis of Infringement Allegations

U.S. Patent No. 10,272,083 Infringement Allegations

Claim Element (from Independent Claim 8) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of treating a mantle cell lymphoma (MCL) in a human subject suffering therefrom Alembic's proposed labeling for its ANDA Product will allegedly direct its use for the treatment of MCL, the approved indication for the reference listed drug, CALQUENCE®. ¶24, ¶41 col. 100:40-42
comprising the step of orally administering, to the human subject, The ANDA Product is formulated as an "oral capsule." ¶31 col. 100:43-44
a dose of 100 mg twice daily of a Bruton's tyrosine kinase (BTK) inhibitor, The ANDA Product is a "100 mg" capsule, and the proposed labeling will allegedly instruct twice-daily administration, consistent with the claimed method. ¶31, ¶41 col. 100:45-46
wherein the BTK inhibitor is a compound of Formula (II) or a pharmaceutically-acceptable salt, hydrate, or solvate thereof. The active ingredient of the ANDA Product is acalabrutinib, which the complaint identifies as the compound of Formula (II). The complaint includes a visual of the compound's structure. ¶31, ¶36, p. 9 col. 100:47-51; col. 32:5-18

Identified Points of Contention

  • Scope Questions: A central question in ANDA litigation involving method-of-use patents is whether the generic drug's proposed label will be found to encourage, recommend, or promote an infringing use. The dispute may focus on whether the instructions and indications on the proposed label meet the legal standard for inducing infringement by physicians and patients.
  • Technical Questions: The complaint alleges the ANDA product contains acalabrutinib. A potential point of contention could arise if Alembic's ANDA Product uses a different salt, hydrate, or solvate form of acalabrutinib than the branded drug, raising the question of whether that specific form falls within the scope of the claim term "pharmaceutically acceptable salt, hydrate, or solvate thereof" as defined by the patent.

V. Key Claim Terms for Construction

  • The Term: "a compound of Formula (II) or a pharmaceutically-acceptable salt, hydrate, or solvate thereof"
  • Context and Importance: This term defines the precise chemical substance covered by the method claim. In an ANDA case, the generic product must contain the same active ingredient as the branded drug. However, disputes can arise if the generic uses a different physical or chemical form (e.g., a novel salt). The construction of the scope of "pharmaceutically acceptable salt, hydrate, or solvate" will be critical to determining whether such a different form infringes. Practitioners may focus on this term because the bioequivalence of a new salt form could be central to both FDA approval and the infringement analysis.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent provides broad definitions for what constitutes a "pharmaceutically acceptable salt," stating it refers to salts "derived from a variety of organic and inorganic counter ions known in the art" and lists numerous examples ('083 Patent, col. 10:51-64). This language may support a construction that is not limited to only the specific forms disclosed in the patent's examples.
    • Evidence for a Narrower Interpretation: The patent describes the specific preparation of the compound of Formula (II) ('083 Patent, col. 31:31-50). A party could argue that the scope of covered forms should be limited by the context of the specific embodiments and synthesis methods described in the detailed description, potentially excluding forms with materially different properties.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement of infringement, stating that Alembic "plans and intends to, and will, actively induce infringement" upon ANDA approval through its proposed product labeling, which will allegedly direct users to perform the claimed method (Compl. ¶¶ 41, 42). The complaint also alleges contributory infringement, stating the ANDA Product and its labeling are "especially made or adapted for use in infringing the '083 patent and that its ANDA Product and its proposed labeling is not suitable for substantial non-infringing use" (Compl. ¶43).
  • Willful Infringement: The complaint alleges that Alembic "has acted with full knowledge of the '083 patent and without a reasonable basis for believing that it would not be liable for infringing" (Compl. ¶45). This allegation is based on pre-suit knowledge allegedly established through prior litigation involving the same parties and patent, as well as the notice letters sent by Alembic (Compl. ¶¶ 27-29, 45).

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

  • A central issue will be one of induced infringement: will the language of Alembic's proposed product label be found to provide specific instructions that actively encourage physicians to prescribe and patients to use the generic product in a manner that directly practices each step of the method claimed in Claim 8 of the '083 patent?
  • A key evidentiary question will be one of objective baselessness: can Plaintiffs demonstrate that Alembic's filing of its Paragraph IV certification—asserting non-infringement or invalidity—was objectively baseless at the time it was made, a necessary element for a finding that the litigation itself is an act of willful infringement?