DCT

1:15-cv-03367

Horizon Pharma Ireland Ltd v. Amneal Pharma LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:15-cv-03367, D.N.J., 05/15/2015
  • Venue Allegations: Venue is alleged to be proper in the District of New Jersey because the Defendant maintains its principal place of business in Bridgewater, New Jersey.
  • Core Dispute: Plaintiff alleges that Defendant's filing of an Abbreviated New Drug Application (ANDA) for a generic version of Plaintiff's PENNSAID® 2% topical solution constitutes infringement of six U.S. patents related to pharmaceutical formulations of diclofenac sodium and methods of their use.
  • Technical Context: The technology concerns topical formulations of diclofenac, a non-steroidal anti-inflammatory drug (NSAID), used for treating pain associated with osteoarthritis, particularly of the knee.
  • Key Procedural History: The litigation was triggered by Defendant’s submission of ANDA No. 208198 to the U.S. Food and Drug Administration (FDA). This submission included a Paragraph IV certification alleging that the patents-in-suit are invalid, unenforceable, or will not be infringed by the proposed generic product. The complaint was filed within the 45-day statutory window following Plaintiff's receipt of Defendant's Paragraph IV notice letter.

Case Timeline

Date Event
2006-10-17 Earliest Priority Date for ’838, ’613, ’809 Patents
2009-03-31 Earliest Priority Date for ’078, ’450, ’164 Patents
2012-07-10 U.S. Patent No. 8,217,078 Issues
2012-08-28 U.S. Patent No. 8,252,838 Issues
2013-10-01 U.S. Patent No. 8,546,450 Issues
2013-10-22 U.S. Patent No. 8,563,613 Issues
2013-12-31 U.S. Patent No. 8,618,164 Issues
2014-10-28 U.S. Patent No. 8,871,809 Issues
2015-04-02 Plaintiff receives Defendant’s Paragraph IV notice letter
2015-05-15 Complaint Filed

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

U.S. Patent No. 8,217,078 - "Treatment of Pain with Topical Diclofenac"

  • Patent Identification: U.S. Patent No. 8,217,078, "Treatment of Pain with Topical Diclofenac," issued July 10, 2012.

The Invention Explained

  • Problem Addressed: The patent background describes the significant gastrointestinal and cardiovascular risks associated with oral NSAIDs commonly used to treat osteoarthritis pain. It notes that while topical NSAIDs offer a potentially safer alternative by reducing systemic exposure, their long-term efficacy has been questioned in the medical literature (ʼ078 Patent, col. 2:24-36; col. 3:1-10).
  • The Patented Solution: The invention is a method of using a specific topical diclofenac formulation that contains dimethyl sulfoxide (DMSO) as a penetration enhancer. The patent claims methods of treating pain that involve informing the user of specific clinical data regarding the formulation's efficacy and safety profile, such as results from clinical trials, adverse event profiles, and instructions on co-applying other topical products like sunscreen ('078 Patent, col. 4:21-67). This approach seeks to patent a method of treatment defined not just by drug application but also by the communication of specific clinical information that distinguishes the treatment regimen.
  • Technical Importance: This patent attempts to secure protection based on novel clinical findings and instructions for use, which can differentiate a branded drug from competitors even if the core formulation is known, by patenting the specific, clinically-validated method of treatment ('078 Patent, col. 4:21-25).

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims without specifying them (Compl. ¶32; Prayer for Relief ¶A). Claim 1 is the first independent claim.
  • Essential elements of Claim 1 include:
    • Applying a first medication consisting of a topical diclofenac preparation with 40-50% w/w dimethyl sulfoxide to a knee of a patient with pain.
    • Waiting for the treated area to dry.
    • Subsequently applying a second medication consisting of a topical medication (selected from an NSAID, tretinoin, minoxidil, or a corticosteroid) to the treated area.
  • The complaint does not explicitly reserve the right to assert dependent claims but makes a general allegation of infringement.

U.S. Patent No. 8,252,838 - "Diclofenac Topical Formulation"

  • Patent Identification: U.S. Patent No. 8,252,838, "Diclofenac Topical Formulation," issued August 28, 2012.

The Invention Explained

  • Problem Addressed: The patent identifies drawbacks with prior liquid topical NSAID formulations, noting they can be slow to dry, runny, and require frequent dosing (three to four times daily), which may lead to skin irritation and poor patient compliance ('838 Patent, col. 2:7-14).
  • The Patented Solution: The invention is a specific topical gel formulation of diclofenac sodium. The formulation comprises diclofenac sodium, DMSO, ethanol, propylene glycol, and a thickening agent (such as hydroxypropyl cellulose) within specified concentration ranges. This gel is described as having superior properties, including a faster drying rate, higher viscosity, and greater transdermal flux compared to the prior art liquid formulations ('838 Patent, col. 4:20-39; Abstract).
  • Technical Importance: The invention aims to improve patient compliance and therapeutic outcomes by providing a more cosmetically elegant and convenient dosage form (a quick-drying gel) that delivers the active ingredient more efficiently than previous liquid versions ('838 Patent, col. 3:9-19).

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims without specification (Compl. ¶42; Prayer for Relief ¶B). Claim 1 is the first independent claim.
  • Essential elements of Claim 1, a composition claim, include:
    • diclofenac sodium at 1-2% w/w
    • DMSO at 40-50% w/w
    • ethanol at 23-29% w/w
    • propylene glycol at 10-12% w/w
    • a thickening agent that is hydroxypropyl cellulose
    • water
    • The formulation must also exhibit three functional properties: (1) a viscosity of 500-5000 centipoise; (2) a greater drying rate than a "comparative liquid formulation"; and (3) a transdermal flux of 1.5 times or greater than the same comparative liquid formulation.
  • The complaint does not explicitly reserve the right to assert dependent claims.

Additional Patents-in-Suit Capsules

  • U.S. Patent No. 8,546,450: "Treatment of Pain with Topical Diclofenac Compounds," issued October 1, 2013.

    • Technology Synopsis: This patent claims methods for treating a patient with a combination therapy that comprises administering an oral NSAID and topically applying a diclofenac preparation to a knee (Compl. ¶19; '450 Patent, Abstract).
    • Asserted Claims: One or more unspecified claims are asserted (Compl. ¶52; Prayer for Relief ¶C).
    • Accused Features: The filing of an ANDA for a product that is a generic version of PENNSAID® 2% is alleged to infringe (Compl. ¶52).

  • U.S. Patent No. 8,563,613: "Diclofenac Topical Formulation," issued October 22, 2013.

    • Technology Synopsis: This patent claims specific topical gel formulations containing diclofenac sodium, DMSO, ethanol, propylene glycol, and a thickening agent, with defined component ranges and functional properties such as viscosity and drying rate (Compl. ¶20; '613 Patent, Abstract).
    • Asserted Claims: One or more unspecified claims are asserted (Compl. ¶62; Prayer for Relief ¶D).
    • Accused Features: Amneal's proposed generic diclofenac sodium topical solution 2% w/w (Compl. ¶62).

  • U.S. Patent No. 8,618,164: "Treatment of Pain with Topical Diclofenac Compounds," issued December 31, 2013.

    • Technology Synopsis: This patent claims methods of applying topical agents to a knee of a patient with pain, similar to the methods claimed in the '078 patent (Compl. ¶21; '164 Patent, Abstract).
    • Asserted Claims: One or more unspecified claims are asserted (Compl. ¶71; Prayer for Relief ¶E).
    • Accused Features: The filing of an ANDA for a product that is a generic version of PENNSAID® 2% is alleged to infringe (Compl. ¶71).

  • U.S. Patent No. 8,871,809: "Diclofenac Topical Formulation," issued October 28, 2014.

    • Technology Synopsis: This patent claims specific topical gel formulations containing diclofenac sodium, DMSO, and other excipients within specified ranges, similar to the '838 and '613 patents (Compl. ¶22; '809 Patent, Abstract).
    • Asserted Claims: One or more unspecified claims are asserted (Compl. ¶81; Prayer for Relief ¶F).
    • Accused Features: Amneal's proposed generic diclofenac sodium topical solution 2% w/w (Compl. ¶81).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentality is Defendant Amneal's proposed "diclofenac sodium topical solution 2% w/w," for which it seeks FDA approval under ANDA No. 208198 ("the Amneal Product") (Compl. ¶10).
  • Functionality and Market Context: The complaint alleges that the Amneal Product is a generic version of Plaintiff's PENNSAID® 2% product, intended for the same therapeutic use: "the relief of pain of osteoarthritis of the knees" (Compl. ¶27). The complaint further alleges that Amneal's ANDA relies upon the PENNSAID® 2% New Drug Application (NDA) and contains data purporting to demonstrate the bioequivalence of the Amneal Product to PENNSAID® 2% (Compl. ¶28). The act of infringement alleged is the filing of the ANDA itself, which seeks approval to market the generic product before the expiration of the patents-in-suit (Compl. ¶30, 32).

IV. Analysis of Infringement Allegations

The complaint does not contain detailed infringement contentions or claim charts. The infringement counts are pleaded generally, alleging that the Amneal Product, if approved and marketed, will infringe one or more claims of each patent-in-suit (Compl. ¶32, 42, 52, 62, 71, 81). The infringement analysis for an ANDA case is a statutorily defined act based on what the generic product's characteristics and prescribed uses will be upon approval. No probative visual evidence provided in complaint.

'078 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method for applying topical agents to a knee of a patient with pain, said method comprising: applying a first medication consisting of a topical diclofenac preparation to an area of the knee of said patient...wherein the topical diclofenac preparation comprises a therapeutically effective amount of diclofenac and 40-50% w/w dimethyl sulfoxide; The infringement theory is that Defendant will induce infringement by physicians and patients. Amneal's proposed product label is expected to instruct users to apply its 2% diclofenac solution, alleged to contain 40-50% DMSO, to the knee for pain relief. ¶32-34 col. 81:13-22
waiting for the treated area to dry; Amneal's label is expected to contain instructions that would lead users to wait for the solution to dry before covering the area with clothing, thereby performing this step. ¶32-34 col. 81:23
and subsequently applying a second medication consisting of a topical medication, which is other than said first medication and is selected from the group consisting of an NSAID, tretinoin, minoxidil, a corticosteroid, to said treated area after said treated area is dry... The complaint does not provide sufficient detail for analysis of this element. Infringement would require the product label to instruct or encourage the application of a second, specific type of topical medication. ¶32-34 col. 81:24-32

'838 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A topical formulation, said topical formulation consisting essentially of: (i) diclofenac sodium present at 1-2% w/w; The Amneal Product is a 2% w/w diclofenac sodium solution, meeting this limitation. ¶27, 42 col. 28:40-42
(ii) DMSO present at 40-50% w/w; (iii) ethanol present at 23-29% w/w; (iv) propylene glycol present at 10-12% w/w; (v) optionally glycerine; (vi) a thickening agent, wherein said thickening agent is hydroxypropyl cellulose; and (vii) water... The complaint alleges the Amneal Product will infringe but does not specify the concentrations of these excipients. Infringement depends on the confidential formulation data in Amneal’s ANDA. ¶42-43 col. 28:43-52
wherein said topical formulation when applied to the skin has a) a greater drying rate; and b) a transdermal flux of 1.5 times or greater than a comparative liquid formulation... The complaint alleges Amneal's product is bioequivalent to PENNSAID® 2%, which Plaintiffs assert has these claimed functional properties. The infringement allegation is that the Amneal Product will necessarily exhibit these same characteristics. ¶28, 42 col. 28:53-62
  • Identified Points of Contention:
    • Scope Questions: For the '078 patent, a primary question will be whether Amneal’s proposed label will instruct or encourage users to perform the complete method, particularly the step of applying a second, specific type of topical medication. Without such instructions, a claim for induced infringement may be difficult to sustain.
    • Technical Questions: For the '838 patent, the central dispute will be factual and technical: Does the precise formulation disclosed in Amneal's confidential ANDA meet every compositional and functional limitation of the asserted claims? This will require discovery into Amneal's formulation and comparative testing against the claimed functional benchmarks (e.g., drying rate, transdermal flux).

V. Key Claim Terms for Construction

  • The Term: "subsequently applying a second medication" (from '078 Patent, Claim 1)

    • Context and Importance: This term is critical because infringement of the method claim requires performance of all steps. Whether Amneal can be held liable for inducing infringement may depend on whether the application of a second, unrelated topical product (like a sunscreen or OTC cream) by a patient is attributable to instructions on Amneal's product label.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent specification explicitly contemplates the application of other common topical products, stating that "once dry, sunscreen, insect repellant, lotion, moisturizer, cosmetics, and/or other topical products can be applied" ('078 Patent, col. 4:65-67). This language may support a construction that does not require the "second medication" to be a prescription drug for a related therapeutic purpose.
      • Evidence for a Narrower Interpretation: The claim language itself lists specific classes of therapeutic agents ("an NSAID, tretinoin, minoxidil, a corticosteroid"). A defendant may argue this context limits the scope to prescription or physician-recommended therapeutic agents, not routine consumer products, making inducement harder to prove.

  • The Term: "consisting essentially of" (from '838 Patent, Claim 1)

    • Context and Importance: This transitional phrase is narrower than "comprising" but broader than "consisting of." Its construction will determine whether Amneal's product avoids infringement by including additional, unlisted ingredients. The dispute will focus on whether any such additional ingredients "materially affect the basic and novel properties" of the invention, which the patent identifies as its specific viscosity, drying rate, and transdermal flux.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation (i.e., allowing more unlisted ingredients): A party could argue that only ingredients that significantly alter the claimed viscosity, drying rate, or flux are material, allowing for minor additives like preservatives or pH adjusters without escaping the claim scope.
      • Evidence for a Narrower Interpretation (i.e., allowing fewer unlisted ingredients): The patent repeatedly emphasizes the importance of the specific combination of listed ingredients to achieve its superior properties ('838 Patent, col. 5:45-51). A party could argue that this emphasis implies that the addition of almost any other active or significant excipient would materially alter the formulation's fundamental character.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon FDA approval and commercial marketing, Defendant will actively induce infringement by physicians, pharmacists, and patients (Compl. ¶34, 44, 54, 63, 73, 83). The basis for this allegation is the expected instructions for use on the Amneal Product's label, which will direct users to apply the product in a manner that allegedly practices the methods claimed in the '078, '450, and '164 patents.
  • Willful Infringement: The complaint alleges that Defendant had "actual and constructive notice" of the patents-in-suit prior to filing its ANDA and that its infringement "has been, and continues to be, willful" (Compl. ¶36, 46, 56, 65, 75, 85). The alleged pre-suit knowledge is based on the patents' listing in the FDA's Orange Book and on Defendant's April 2, 2015 Paragraph IV notice letter (Compl. ¶25, 29).

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

  • A core issue will be one of evidentiary proof: For the formulation patents ('838, '613, '809), the dispute will center on whether the precise quantitative composition of Amneal's proposed generic product, as confidentially disclosed in its ANDA, falls within the claimed percentage ranges and demonstrably exhibits the claimed functional properties, such as viscosity, drying rate, and transdermal flux.
  • A key legal question will be one of induced infringement: For the method-of-use patents ('078, '450, '164), the case may turn on whether Amneal's proposed product labeling will be found to contain instructions or recommendations that encourage users to perform every step of the claimed methods, thereby satisfying the specific intent requirement for inducement under 35 U.S.C. § 271(b).
  • A central question of claim scope will be the interpretation of the phrase "consisting essentially of" in the formulation patents. The outcome of the infringement analysis could depend on whether any additional, unlisted ingredients in Amneal's product are found to materially alter the claimed "basic and novel properties" of the invention.