Almirall LLC v. Taro Pharma Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Almirall, LLC (Pennsylvania); Almirall, S.A. (Spain); Atnx SPV, LLC (Delaware)
  • Defendant: Taro Pharmaceuticals, Inc. (Canada)
  • Plaintiff's Counsel: Morris, Nichols, Arsht & Tunnell LLP
• Case Identification: 1:25-cv-00385, D. Del., 03/28/2025
• Venue Allegations: Venue is alleged as proper against a foreign defendant in any judicial district pursuant to 28 U.S.C. §§ 1391(c)(3) and 1400(b).
• Core Dispute: Plaintiffs allege that Defendant's submission of an Abbreviated New Drug Application (ANDA) to market a generic version of the topical ointment Klisyri® infringes six U.S. patents covering the active ingredient tirbanibulin, its compositions, and methods of use.
• Technical Context: The technology relates to pharmaceutical compositions and methods for treating actinic keratosis, a common precancerous skin condition caused by sun exposure.
• Key Procedural History: The lawsuit is an ANDA action initiated under the Hatch-Waxman Act, triggered by Defendant's submission of ANDA No. 220075 and a Paragraph IV Certification notice letter dated February 14, 2025, which asserted that the patents-in-suit are invalid, unenforceable, and/or will not be infringed. The patents-in-suit are listed in the FDA's "Orange Book" for the branded drug Klisyri®.

Case Timeline

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

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

The Invention Explained

• Problem Addressed: The patent describes a need for new treatments for cell proliferation disorders and cancer, noting that existing drug therapies for metastatic disease are often palliative rather than curative Compl. ¶14 '931 Patent, col. 1:12-25
• The Patented Solution: The invention provides a class of bi-aryl compounds designed to modulate kinase signaling cascades, which are crucial pathways for cell functions like proliferation '931 Patent, abstract Specifically, the compounds are described as being useful for treating diseases modulated by Src kinase and focal adhesion kinase (FAK) '931 Patent, col. 5:45-52
• Technical Importance: The development of small-molecule kinase inhibitors represented a significant therapeutic strategy for oncology and other proliferation-related disorders during this time period '931 Patent, col. 12:4-8

Key Claims at a Glance

• The complaint asserts infringement of claims 1-11 of the '931 patent Compl. ¶30
• Independent claim 1 covers a compound of Formula I, which is defined by a core chemical structure and a list of possible chemical groups for various substituents (R groups, T, X, Y, and Z variables) '931 Patent, claim 1 The essential elements include:
  • A central bi-aryl core structure where two ring systems are linked.
  • A specific linker group (T) connecting the two rings.
  • A defined set of atoms (Xa-Xe) making up one of the rings.
  • A defined set of atoms (Xz, Xy) making up the other ring.
  • A specific substituent group (Z) attached to one of the rings.
  • A list of possible chemical moieties for various other substituent positions (R groups, Y).

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

The Invention Explained

• Problem Addressed: The patent background explains that while a prior patent ('931 Patent) disclosed the compound KX2-391 (tirbanibulin), its synthesis was impractical for large quantities and resulted in contamination with ethyl chloride, a weak alkylating agent, which could limit pharmaceutical effectiveness '470 Patent, col. 2:30-36
• The Patented Solution: The invention provides compositions and processes for the synthesis of "substantially pure" N-benzyl-2-(5-(4-(2-morpholinoethoxy)phenyl)pyridin-2-yl)acetamide (KX2-391) and its salts '470 Patent, abstract The described synthesis is intended to be safe, simple, high-yield, and produce the compound with limited impurities, making it suitable for large-scale pharmaceutical production '470 Patent, col. 12:1-5
• Technical Importance: Developing a scalable and high-purity synthesis process is a critical step in transforming a promising chemical compound into a viable pharmaceutical product '470 Patent, col. 2:37-41

Key Claims at a Glance

• The complaint asserts infringement of claims 1-25 of the '470 patent Compl. ¶36
• Independent claim 1 covers a composition comprising "substantially pure" N-benzyl-2-(5-(4-(2-morpholinoethoxy)phenyl)pyridin-2-yl)acetamide or a pharmaceutically acceptable salt thereof '470 Patent, claim 1
• Independent claim 8 covers a method of treating a cell proliferation disorder by administering a composition comprising the compound of claim 1 '470 Patent, claim 8
• Independent claim 25 covers a process for synthesizing the compound '470 Patent, claim 25

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

• Technology Synopsis: The patent is directed to pharmaceutical compositions comprising the "free base" form of 2-(5-(4-(2-morpholinoethoxy)phenyl)pyridin-2-yl)-N-benzylacetamide (tirbanibulin) '001 Patent, abstract Compl. ¶42 This focuses on the specific chemical form of the active pharmaceutical ingredient.
• Asserted Claims: Claim 1 (independent) is asserted Compl. ¶42
• Accused Features: The complaint alleges that Taro's ANDA Product would, if approved and marketed, constitute a pharmaceutical composition comprising the claimed free base, thereby infringing claim 1 Compl. ¶¶42-43

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

• Technology Synopsis: The patent is directed to methods of treating or preventing actinic keratosis by topically administering a therapeutically effective amount of the compound KX-01 (tirbanibulin) '693 Patent, abstract The claims specify dosages and treatment regimens Compl. ¶48
• Asserted Claims: Claims 1-25 are asserted Compl. ¶48
• Accused Features: The complaint alleges that the manufacture, use, or sale of Taro's ANDA Product would infringe, which in the context of a method-of-use claim implies that the product's proposed labeling will instruct medical providers and patients to use the product in an infringing manner Compl. ¶48

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

• Technology Synopsis: This patent is directed to specific solid-state forms, or polymorphs, of tirbanibulin '236 Patent, abstract Polymorphism can affect a drug's stability, solubility, and bioavailability, and is a common subject of pharmaceutical patenting Compl. ¶54
• Asserted Claims: Claims 1-10 are asserted Compl. ¶54
• Accused Features: The complaint alleges that Taro's ANDA Product will contain or be manufactured using the claimed polymorphs of tirbanibulin Compl. ¶54

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

• Technology Synopsis: Similar to the '693 patent, this patent is directed to methods of treating or preventing actinic keratosis by administering tirbanibulin '750 Patent, abstract The claims specify particular dosages and affected areas Compl. ¶60
• Asserted Claims: Claims 1-23 are asserted Compl. ¶60
• Accused Features: The complaint alleges that the use of Taro's ANDA Product in accordance with its proposed labeling would infringe the claimed methods Compl. ¶60

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendant Taro's Abbreviated New Drug Application (ANDA) No. 220075 Product (the "Taro ANDA Product") Compl. ¶23

Functionality and Market Context

The Taro ANDA Product is a generic version of Almirall's Klisyri®, which is a "tirbanibulin topical ointment 1%" Compl. ¶23 The product is intended for the treatment of actinic keratosis Compl. ¶48 Compl. ¶60 The complaint alleges that Taro's ANDA relies on the Klisyri® New Drug Application and contains data purporting to demonstrate bioequivalence to Klisyri® Compl. ¶24 The filing of the ANDA seeks FDA approval to market this generic product prior to the expiration of the patents-in-suit Compl. ¶1

IV. Analysis of Infringement Allegations

The complaint does not provide a detailed, element-by-element infringement analysis or include claim charts. The infringement allegations are premised on the statutory act of infringement under 35 U.S.C. § 271(e)(2)(A), which makes the submission of an ANDA seeking approval to market a generic version of a patented drug an act of infringement.

The narrative theory of infringement is that Taro's ANDA Product is a generic copy of Klisyri® (tirbanibulin topical ointment 1%) and will have the same active ingredient, formulation characteristics, and method of use as the branded product Compl. ¶¶23-24 Because the patents-in-suit are listed in the FDA's Orange Book as covering Klisyri®, Plaintiffs allege that the future, hypothetical commercial manufacture, use, or sale of the Taro ANDA Product would infringe the asserted claims Compl. ¶30 Compl. ¶36 Compl. ¶42 Compl. ¶48 Compl. ¶54 Compl. ¶60 For the method-of-use patents ('693 and '750 Patents), the infringement theory is based on inducement, where the label proposed in the ANDA will instruct users to perform the patented methods.

No probative visual evidence provided in complaint.

• Identified Points of Contention:
  • Technical Questions: A primary technical question, not addressed by the complaint, will be whether the active pharmaceutical ingredient in the Taro ANDA Product is identical to that claimed in the patents. For instance, does it meet the "substantially pure" limitation of the '470 Patent? Does it consist of the specific polymorphs claimed in the '236 Patent? While Taro's product may be bioequivalent to Klisyri®, it may not meet every limitation of the asserted composition claims, raising the possibility of a non-infringement defense based on formulation differences.
  • Scope Questions: For the method-of-use patents ('693 and '750 Patents), a potential point of contention may arise from the scope of the proposed label for Taro's product. The question will be whether the instructions on Taro's label direct users to perform all the steps of the asserted method claims.

V. Key Claim Terms for Construction

• The Term: "substantially pure" (from claim 1 of the '470 Patent)
• Context and Importance: This term is a term of degree and is central to the infringement analysis for the '470 Patent. The definition of "substantially pure" will determine the level of impurities allowable in an accused product. Practitioners may focus on this term because Taro could argue its product, while bioequivalent, falls outside the scope of "substantially pure" as defined by the patent.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent does not provide an explicit numerical floor for the term in the claims, which may support an argument that the term should be given its plain and ordinary meaning in the context of pharmaceutical manufacturing, potentially allowing for more than trace impurities.
  • Evidence for a Narrower Interpretation: The specification repeatedly discusses the goal of producing "highly purified KX2-391 (>98.0% as determined by HPLC)" ('470 Patent, related '001 Patent, col. 11:67-68). The patent also details specific impurities, such as ethyl chloride, and sets forth compositions with very low levels of such impurities (e.g., less than 250 ppm) '001 Patent, col. 12:21-24 This language may support a narrower construction requiring a specific percentage purity or the absence of particular impurities.

VI. Other Allegations

• Indirect Infringement: The complaint does not explicitly plead "inducement" or "contributory" infringement. However, for the method-of-use claims in the '693 and '750 patents, the infringement allegation is based on the future use of the Taro ANDA Product Compl. ¶48 Compl. ¶60 In the context of an ANDA case, this is an allegation of induced infringement under 35 U.S.C. § 271(b), where the knowledge and intent elements are allegedly satisfied by Taro's filing of an ANDA with a proposed label that instructs users to perform the patented methods.
• 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 Compl. ¶39 Compl. ¶45 Compl. ¶51 Compl. ¶57 Compl. ¶63 Plaintiffs also request a finding that the case is "exceptional" and an award of attorneys' fees under 35 U.S.C. § 285 Compl. ¶33 Compl. ¶39 Compl. ¶45 Compl. ¶51 Compl. ¶57 Compl. ¶63 These allegations form the basis for a potential claim of willful infringement based on pre-suit knowledge.

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

• A central issue will be one of technical non-infringement: can Taro demonstrate that its ANDA product, while bioequivalent to Klisyri®, is formulated in a way that avoids at least one essential limitation of the asserted composition claims? This may turn on, for example, the purity level of the active ingredient relative to the term "substantially pure" in the '470 patent, or the use of a different, non-infringing polymorph than those claimed in the '236 patent.
• A second core issue will be invalidity: what will be the basis for Taro's assertion in its Paragraph IV letter that the patents are invalid? The case will likely involve significant disputes over whether the claimed inventions-from the core compound to specific solid forms and methods of use-were obvious in light of the prior art at the time of their respective priority dates.
• A final key question will be one of claim scope: how will the court construe key claim terms of degree, such as "substantially pure"? The interpretation of such terms will be critical in determining whether Taro's product, which is not yet on the market and whose precise composition is not detailed in the complaint, falls within the scope of the patent claims.