DCT

1:25-cv-00385

Almirall LLC v. Taro Pharma Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00385, D. Del., 03/28/2025
  • Venue Allegations: Venue is alleged to be proper under 28 U.S.C. §§ 1391(c)(3) and 1400(b) on the basis that a patent infringement action against a foreign defendant may be brought in any judicial district.
  • Core Dispute: Plaintiffs allege that Defendant’s submission of an Abbreviated New Drug Application (ANDA) to market a generic version of the pharmaceutical product Klisyri® constitutes infringement of six U.S. patents covering the drug’s active ingredient, compositions, and methods of use.
  • Technical Context: The dispute centers on tirbanibulin, the active pharmaceutical ingredient in Klisyri®, which is a topical ointment used for the treatment of actinic keratosis, a common precancerous skin condition caused by sun exposure.
  • Key Procedural History: This action was initiated under the Hatch-Waxman Act following Defendant Taro’s submission of ANDA No. 220075 and a subsequent Paragraph IV Certification notice letter, which asserted that the patents-in-suit are invalid, unenforceable, and/or will not be infringed by its proposed generic product. The complaint was filed within the 45-day statutory window, triggering an automatic stay of FDA approval for Taro's ANDA.

Case Timeline

Date Event
2004-12-28 Earliest Priority Date for ’931 Patent
2006-12-28 Earliest Priority Date for ’470 and ’001 Patents
2007-11-27 ’931 Patent Issued
2010-12-14 ’470 Patent Issued
2017-03-10 Earliest Priority Date for ’693 and ’750 Patents
2017-09-07 Earliest Priority Date for ’236 Patent
2019-06-18 ’001 Patent Issued
2020-04-14 ’693 Patent Issued
2020-06-02 ’236 Patent Issued
2022-11-15 ’750 Patent Issued
2025-02-14 Taro sends Paragraph IV Certification Notice Letter
2025-03-28 Complaint Filed

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

U.S. Patent No. 7,300,931 - "Compositions for Treating Cell Proliferation Disorders"

  • Patent Identification: U.S. Patent No. 7,300,931, "Compositions for Treating Cell Proliferation Disorders", issued November 27, 2007.

The Invention Explained

  • Problem Addressed: The patent addresses the need for new drugs to treat cell proliferation disorders, noting that cancer is the second leading cause of death in the United States and that existing therapies for metastatic disease are often palliative rather than curative (’931 Patent, col. 1:12-25).
  • The Patented Solution: The invention provides a class of bi-aryl compounds, including the specific chemical structure that would become known as tirbanibulin, which are designed to treat diseases modulated by tyrosine kinase inhibition (’931 Patent, col. 2:44-50; Abstract). The patent describes these compounds as useful anti-proliferative agents for treating mammals (’931 Patent, col. 2:34-37).
  • Technical Importance: The invention provided a novel chemical scaffold for inhibiting Src kinase and focal adhesion kinase (FAK), two pathways implicated in cancer progression and other cell proliferation disorders (’931 Patent, col. 2:48-52).

Key Claims at a Glance

  • The complaint asserts Claims 1-11 (Compl. ¶30). The independent claims in this range are Claim 1 and Claim 6.
  • Independent Claim 1 recites:
    • A compound having a specific chemical formula (Formula I), or a salt, tautomer, solvate, hydrate, or prodrug thereof.
  • Independent Claim 6 recites:
    • A compound having a specific chemical formula.
  • The complaint alleges infringement of dependent claims 2-5 and 7-11 as well (Compl. ¶30).

U.S. Patent No. 7,851,470 - "Composition and Methods for Modulating a Kinase Cascade"

  • Patent Identification: U.S. Patent No. 7,851,470, "Composition and Methods for Modulating a Kinase Cascade", issued December 14, 2010.

The Invention Explained

  • Problem Addressed: The patent describes a need for compositions and processes for synthesizing highly purified KX2-391 (tirbanibulin) (’470 Patent, col. 2:35-41). It notes that a previous small-scale synthesis was impractical for large quantities and resulted in contamination with ethyl chloride, a weak alkylating agent that could limit the drug's effectiveness (’470 Patent, col. 2:29-35).
  • The Patented Solution: The patent discloses compositions of "substantially pure" tirbanibulin and its salts, along with processes for their synthesis (’470 Patent, Abstract). The described methods are intended to produce the compound in high yield (>80%) and with limited impurities, making it suitable for pharmaceutical use (’470 Patent, col. 3:28-34).
  • Technical Importance: This invention provided a scalable manufacturing process and purity standards for a promising therapeutic compound, a critical step in transitioning a drug candidate from laboratory discovery to clinical development and commercialization.

Key Claims at a Glance

  • The complaint asserts Claims 1-25 (Compl. ¶36). The independent claims in this range are Claim 1, Claim 8, Claim 17, and Claim 25.
  • Independent Claim 1 recites:
    • A composition comprising substantially pure N-benzyl-2-(5-(4-(2-morpholinoethoxy)phenyl)pyridin-2-yl)acetamide, and salts, solvates, hydrates, or prodrugs thereof.
  • Independent Claim 8 recites:
    • A method of treating or preventing a cell proliferation disorder by administering a pharmaceutical composition that includes the compound.
  • Independent Claim 17 recites:
    • A method of treating or preventing a disease modulated by tyrosine kinase inhibition by administering the pharmaceutical composition.
  • Independent Claim 25 recites:
    • A composition comprising the dihydrochloride salt of the compound.
  • The complaint asserts infringement of all claims 1-25 (Compl. ¶36).

U.S. Patent No. 10,323,001 - "Compositions for Modulating a Kinase Cascade and Methods of Use Thereof"

  • Patent Identification: U.S. Patent No. 10,323,001, "Compositions for Modulating a Kinase Cascade and Methods of Use Thereof", issued June 18, 2019.
  • Technology Synopsis: The patent addresses the need for a form of the tirbanibulin compound with desirable physical properties related to stability, hygroscopicity, and crystallinity for pharmaceutical formulation (’001 Patent, col. 2:51-60). The invention provides pharmaceutical compositions comprising the "free base" form of tirbanibulin, as distinct from its salt forms (’001 Patent, Abstract; col. 7:42-45).
  • Asserted Claims: Claim 1 (Compl. ¶42). Claim 1 is independent.
  • Accused Features: Taro's proposed generic tirbanibulin topical ointment is alleged to be a pharmaceutical composition that infringes this patent (Compl. ¶¶ 41-42).

U.S. Patent No. 10,617,693 - "Methods of Treating and/or Preventing Actinic Keratosis"

  • Patent Identification: U.S. Patent No. 10,617,693, "Methods of Treating and/or Preventing Actinic Keratosis", issued April 14, 2020.
  • Technology Synopsis: The patent addresses the need for further treatments for actinic keratosis, a prevalent precancerous skin condition (’693 Patent, col. 1:12-32). The invention provides a method of treating actinic keratosis by administering a therapeutically effective amount of the compound KX-01 (tirbanibulin) to a subject in need thereof (’693 Patent, Abstract).
  • Asserted Claims: Claims 1-25 (Compl. ¶48). The independent claims are 1 and 19.
  • Accused Features: Taro’s proposed generic product, intended for the treatment of actinic keratosis, is alleged to practice the patented method of use (Compl. ¶¶ 47-48).

U.S. Patent No. 10,669,236 - "Solid Forms of 2-(5-(4-(2-Morpholino-ethoxy)Phenyl)Pyridin-2-yl)-N-Benzylacetamide"

  • Patent Identification: U.S. Patent No. 10,669,236, "Solid Forms of 2-(5-(4-(2-Morpholino-ethoxy)Phenyl)Pyridin-2-yl)-N-Benzylacetamide", issued June 2, 2020.
  • Technology Synopsis: The patent addresses the urgent need to discover solid forms of tirbanibulin with desirable physicochemical properties, noting that polymorphism affects solubility, stability, and reactivity (’236 Patent, col. 2:41-51). The invention discloses specific crystalline solid forms (polymorphs) of the compound, designated as Forms A, B, and C, and methods of preparing them (’236 Patent, Abstract).
  • Asserted Claims: Claims 1-10 (Compl. ¶54). The independent claims are 1, 5, and 8.
  • Accused Features: Taro's proposed solid-form generic drug is alleged to embody the patented polymorphs (Compl. ¶¶ 53-54).

U.S. Patent No. 11,497,750 - "Methods of Treating and/or Preventing Actinic Keratosis"

  • Patent Identification: U.S. Patent No. 11,497,750, "Methods of Treating and/or Preventing Actinic Keratosis", issued November 15, 2022.
  • Technology Synopsis: Like the ’693 Patent, this patent addresses the need for treatments for actinic keratosis (’750 Patent, col. 1:12-32). The invention claims a method of treating the condition by administering a specific dose of KX-01 (tirbanibulin) within a defined range (e.g., from about 0.001 mg/cm² to about 0.4 mg/cm²) to an affected area of a specific size (’750 Patent, Abstract; col. 2:7-9).
  • Asserted Claims: Claims 1-23 (Compl. ¶60). The independent claims are 1, 14, and 23.
  • Accused Features: Taro’s proposed generic product, with its corresponding dosage and administration instructions, is alleged to practice the patented method of use (Compl. ¶¶ 59-60).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendant Taro’s generic version of tirbanibulin topical ointment, 1%, for which it submitted ANDA No. 220075 to the FDA seeking approval for marketing (Compl. ¶¶ 1, 23). This product is referred to as the "Taro ANDA Product" (Compl. ¶1).

Functionality and Market Context

The complaint alleges that the Taro ANDA Product is a generic version of Almirall's branded pharmaceutical product, Klisyri® (Compl. ¶1). Taro’s ANDA is said to refer to and rely on the Klisyri® New Drug Application (NDA) and to contain data demonstrating the bioequivalence of its generic version to Klisyri® (Compl. ¶24). The product is a topical ointment intended for the treatment of actinic keratosis (Compl. ¶¶ 17, 48). By filing an ANDA, Taro seeks to enter the market with a lower-cost generic alternative to the branded Klisyri® product prior to the expiration of the patents-in-suit (Compl. ¶1).

IV. Analysis of Infringement Allegations

The complaint does not contain a claim chart or detailed, element-by-element infringement allegations for any of the asserted patents. Instead, the infringement theory is predicated on the nature of the ANDA regulatory framework under the Hatch-Waxman Act. The complaint alleges that the patents-in-suit are listed in the FDA's "Orange Book" as covering Klisyri® and its use (Compl. ¶22). It further alleges that Taro’s ANDA seeks approval to market a generic version of tirbanibulin topical ointment, 1%, that is bioequivalent to Klisyri® (Compl. ¶¶ 23, 24). The central allegation is that because Taro seeks to market a generic copy of the branded drug, the future commercial manufacture, use, offer for sale, or sale of the Taro ANDA Product would infringe the asserted claims of the patents-in-suit, which cover the branded drug's active ingredient, compositions, and approved methods of use (Compl. ¶¶ 30, 36, 42, 48, 54, 60). The filing of the ANDA itself is asserted as the statutory act of infringement under 35 U.S.C. § 271(e)(2)(A) (Compl. ¶29).

  • Identified Points of Contention: The complaint notes that Taro’s Paragraph IV Certification asserts that the patents-in-suit are "invalid, unenforceable, and/or will not be infringed" (Compl. ¶25). Given that the accused product is intended to be a bioequivalent generic, the dispute will likely focus less on factual questions of how the product is formulated and more on legal questions of claim scope and validity.
    • Scope Questions: Key disputes may arise over the proper construction of claim terms. For instance, in the context of the ’470 Patent, a central question may be: What is the proper construction of "substantially pure," and does the purity profile of Taro's ANDA product fall within the scope of that term as properly construed?
    • Validity Questions: A primary point of contention will be Taro’s assertion of invalidity. This raises the question: What prior art or other grounds will Taro rely on to argue that the claims covering the compound, its formulation, and its FDA-approved use are invalid as anticipated or obvious?

No probative visual evidence provided in complaint.

V. Key Claim Terms for Construction

For the ’931 Patent

  • The Term: "a compound according to the formula" (from Claim 1)
  • Context and Importance: This term, followed by a chemical structure, defines the molecular entity covered by the patent's core composition claims. The scope of this term is fundamental, as infringement hinges on whether Taro's active pharmaceutical ingredient, tirbanibulin, is encompassed by this formula. While the chemical structure appears definite, disputes can arise over stereoisomers, tautomers, or other variants if not explicitly addressed.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: Claim 1 itself states the invention covers "a salt, tautomer, solvate, hydrate, or prodrug thereof," suggesting the patentee intended the claim to cover more than the single, exact structure depicted (’931 Patent, col. 81:14-15). The specification provides broad definitions for these variants (’931 Patent, col. 29-30).
    • Evidence for a Narrower Interpretation: The patent provides specific, detailed synthesis examples for particular compounds falling under the formula, such as Compound 133 and 134 (’931 Patent, Tables 1-2). A defendant might argue that the scope should be understood in light of these concrete working examples rather than expansive definitions.

For the ’470 Patent

  • The Term: "substantially pure" (from Claim 1)
  • Context and Importance: This term is critical for defining the required level of purity for the claimed composition. Infringement may turn on whether Taro's ANDA product meets this purity threshold. Practitioners may focus on this term because pharmaceutical patents often use such relative terms, which can be a focal point of litigation regarding both infringement and indefiniteness.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification does not provide a specific numerical percentage for "substantially pure." A plaintiff might argue this was intentional, allowing for a flexible definition based on what one of skill in the art would have understood as sufficiently pure for pharmaceutical use at the time.
    • Evidence for a Narrower Interpretation: The patent background criticizes a prior synthesis for producing "contamination with ethyl chloride" and emphasizes a process that produces the compound in "high yield (>80%) and with limited impurities" (’470 Patent, col. 2:33-35). A defendant could argue that "substantially pure" must be read in this context to mean, at a minimum, free from specific contaminants like ethyl chloride or possessing a purity level consistent with the results of the disclosed synthesis methods.

VI. Other Allegations

  • Indirect Infringement: The complaint does not plead separate counts for induced or contributory infringement under 35 U.S.C. § 271(b) or (c). The action is based on the statutory act of infringement created by the filing of an ANDA under 35 U.S.C. § 271(e)(2)(A) (Compl. ¶29).
  • Willful Infringement: The complaint alleges for each patent-in-suit that "Taro was aware of the [asserted] patent when it submitted its ANDA" (Compl. ¶¶ 33, 39, 45, 51, 57, 63). This allegation of pre-suit knowledge, coupled with the request for a finding that the case is "exceptional and to an award of attorney's fees under 35 U.S.C. § 285," forms the basis for a claim of willful infringement.

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

This ANDA litigation will likely center on two main areas: claim construction and patent validity. The complaint, typical for such cases, provides a procedural basis for the suit without detailing the substantive technical and legal arguments that will emerge.

  • A core issue will be one of definitional scope: How will the court construe key claim limitations such as "substantially pure" from the ’470 Patent or the scope of the chemical structures in the ’931 and ’236 patents? The outcome of these claim construction disputes may be dispositive of infringement.
  • A second central question will be one of validity: As signaled by its Paragraph IV certification, Taro will challenge the validity of the asserted patents. The key question for the court will be whether the combination of patents, which cover the tirbanibulin compound from its initial discovery through its specific crystalline forms and methods of use for actinic keratosis, can withstand challenges based on prior art or other invalidity grounds such as obviousness or lack of enablement.