DCT

1:15-cv-01152

Purdue Pharma LP v. Amneal Pharma LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:15-cv-01152, D. Del., 12/15/2015
  • Venue Allegations: Venue is alleged to be proper as Defendant is a Delaware limited liability company.
  • Core Dispute: Plaintiffs allege that Defendant’s submission of an Abbreviated New Drug Application (ANDA) to market generic versions of OxyContin® infringes twelve patents related to oxycodone formulations, purity, and abuse-deterrence features.
  • Technical Context: The technology relates to extended-release opioid analgesics, a critical market for pain management that is also associated with significant public health concerns regarding prescription drug abuse.
  • Key Procedural History: The complaint details extensive prior litigation concerning several of the patents-in-suit. In previous lawsuits involving Teva Pharmaceuticals and Amneal, certain claims of the ’799, ’800, ’072, ’383, ’060, and ’888 patents were found infringed but were also held invalid for reasons including obviousness, anticipation, or indefiniteness. Plaintiffs state that appeals of these invalidity judgments are pending and argue that collateral estoppel should not apply to the present case, alleging they did not have a "full and fair opportunity" to litigate validity in the prior actions.

Case Timeline

Date Event
2001-08-06 Earliest Priority Date for ’888, ’976, ’376 Patents
2003-08-06 Earliest Priority Date for ’383, ’060 Patents
2004-03-30 Earliest Priority Date for ’799, ’800, ’072, ’933 Patents
2006-08-25 Earliest Priority Date for ’741, ’987, ’988 Patents
2010-03-09 Issue Date for ’799, ’800, ’072 Patents
2011-09-27 Defendant files original ANDA No. 203235 (on or before this date)
2012-02-14 Issue Date for ’383 Patent
2012-11-13 Issue Date for ’060 Patent
2012-12-25 Issue Date for ’888 Patent
2014-08-19 Issue Date for ’741 Patent
2014-11-25 Issue Date for ’987, ’988 Patents
2015-05-19 Issue Date for ’376 Patent
2015-06-23 Issue Date for ’976 Patent
2015-07-07 Issue Date for ’933 Patent
2015-10-30 Defendant files Amended ANDA (on or before this date)
2015-11-02 Plaintiffs receive Notice of Paragraph IV Certification (on or about this date)
2015-12-15 Complaint Filing Date

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

U.S. Patent No. 7,674,799 - "OXYCODONE HYDROCHLORIDE HAVING LESS THAN 25 PPM 14-HYDROXYCODEINone"

The Invention Explained

  • Problem Addressed: The patent’s background section describes that the synthesis of oxycodone from thebaine can create an impurity, 14-hydroxycodeinone, and an overoxidized by-product, 8,14-dihydroxy-7,8-dihydrocodeinone, which can later convert into 14-hydroxycodeinone ('799 Patent, col. 1:63 - col. 2:6). Commercially available oxycodone hydrochloride active pharmaceutical ingredient (API) at the time contained levels of 14-hydroxycodeinone greater than 100 parts per million (ppm) ('799 Patent, col. 2:7-12).
  • The Patented Solution: The invention provides an oxycodone hydrochloride composition with a reduced amount of the 14-hydroxycodeinone impurity, specifically less than 25 ppm ('799 Patent, col. 2:25-29). This is achieved through processes, such as hydrogenation, that can reduce the level of the impurity in the final product ('799 Patent, col. 2:50-59). Figure 2 illustrates the chemical dehydration of the by-product into the 14-hydroxycodeinone impurity ('799 Patent, Fig. 2).
  • Technical Importance: The invention addresses a continuing need for a purer oxycodone hydrochloride composition with reduced levels of a specific impurity compared to then-existing commercial products ('799 Patent, col. 2:13-17).

Key Claims at a Glance

  • The complaint asserts independent claims 1-3 (Compl. ¶71).
  • Essential elements of independent claim 1 include:
    • An oral dosage form
    • comprising from about 5 mg to about 320 mg of oxycodone hydrochloride
    • having less than 25 ppm 14-hydroxycodeinone
    • wherein at least a portion of the 14-hydroxycodeinone is derived from 8α,14-dihydroxy-7,8-dihydrocodeinone
  • The complaint reserves the right to assert various dependent claims (Compl. ¶71).

U.S. Patent No. 7,674,800 - "OXYCODONE HYDROCHLORIDE HAVING LESS THAN 25 PPM 14-HYDROXYCODEINONE"

The Invention Explained

  • Problem Addressed: As with the related ’799 patent, the ’800 Patent addresses the problem of 14-hydroxycodeinone impurity in oxycodone hydrochloride API derived from thebaine ('800 Patent, col. 1:22 - col. 2:15).
  • The Patented Solution: The invention is directed to a process for preparing an oxycodone salt that is "substantially free of 14-hydroxycodeinone" by hydrogenating a composition containing the impurity ('800 Patent, Abstract). It also claims the final oxycodone hydrochloride composition prepared by this specific claimed process ('800 Patent, col. 2:24-33).
  • Technical Importance: The patented process provides a specific method for producing a purer oxycodone API, thereby addressing the need for compositions with reduced impurity levels ('800 Patent, col. 2:16-20).

Key Claims at a Glance

  • The complaint asserts independent claims 1, 38, and 57 (Compl. ¶77).
  • Essential elements of independent claim 38 (a product-by-process claim) include:
    • An oxycodone hydrochloride composition
    • having less than 25 ppm 14-hydroxycodeinone
    • prepared by a process comprising hydrogenating a 14-hydroxycodeinone composition in a solvent to form an oxycodone free base composition.
  • The complaint reserves the right to assert various dependent claims (Compl. ¶77).

Multi-Patent Capsules

  • Patent Identification: U.S. Patent No. 7,683,072, "OXYCODONE HYDROCHLORIDE HAVING LESS THAN 25 PPM 14-HYDROXYCODEINONE," issued March 9, 2010.

  • Technology Synopsis: Belonging to the same family as the '799 and '800 patents, this patent claims a composition of oxycodone hydrochloride with less than 25 ppm of the 14-hydroxycodeinone impurity, where a portion of that impurity is derived from a specific precursor compound (Compl. ¶¶23, 83).

  • Asserted Claims: Independent claim 1 (Compl. ¶83).

  • Accused Features: Defendant's Amended ANDA Products are alleged to be covered by the claims (Compl. ¶83).

  • Patent Identification: U.S. Patent No. 8,114,383, "ABUSE-PROOFED DOSAGE FORM," issued February 14, 2012.

  • Technology Synopsis: This patent describes a pharmaceutical dosage form designed to be abuse-resistant. The formulation includes an active ingredient with abuse potential mixed with a high molecular weight polyalkylene oxide, which imparts a breaking strength of at least 500 Newtons, making it difficult to crush or pulverize for abuse (Compl. ¶¶31, 89).

  • Asserted Claims: Independent claim 1 and dependent claim 5 (Compl. ¶89).

  • Accused Features: Defendant's Amended ANDA Products are alleged, on information and belief, to meet the claimed composition and breaking strength requirements (Compl. ¶89).

  • Patent Identification: U.S. Patent No. 8,309,060, "ABUSE-PROOFED DOSAGE FORM," issued November 13, 2012.

  • Technology Synopsis: This patent discloses an abuse-proofed, thermoformed dosage form containing an active ingredient with abuse potential and at least one high molecular weight polymer. The formulation is designed to have a breaking strength of at least 500 Newtons to deter physical manipulation for abuse purposes (Compl. ¶¶32, 95).

  • Asserted Claims: Independent claims 1 and 28, and dependent claim 25 (Compl. ¶95).

  • Accused Features: Defendant's Amended ANDA Products are alleged, on information and belief, to be covered by the claims (Compl. ¶95).

  • Patent Identification: U.S. Patent No. 8,337,888, "PHARMACEUTICAL FORMULATION CONTAINING GELLING AGENT," issued December 25, 2012.

  • Technology Synopsis: This patent covers a controlled-release oral dosage form containing oxycodone and a gelling agent, polyethylene oxide. The gelling agent is intended to impart a high viscosity when the dosage form is tampered with by dissolving it in a liquid, making it difficult to draw into a syringe for injection (Compl. ¶¶51, 108).

  • Asserted Claims: Independent claim 1 (Compl. ¶108).

  • Accused Features: Defendant's Amended ANDA Products are alleged to be covered by the claims (Compl. ¶108).

  • Patent Identification: U.S. Patent No. 8,808,741, "TAMPER RESISTANT DOSAGE FORMS," issued August 19, 2014.

  • Technology Synopsis: The patent claims a method for treating pain by administering a "convection cured tablet" that includes an extended-release matrix. The matrix comprises at least one high molecular weight polyethylene oxide and oxycodone, providing tamper-resistant properties (Compl. ¶¶59, 114).

  • Asserted Claims: Independent claims 1, 6, and 17 (Compl. ¶114).

  • Accused Features: The administration of Defendant's Amended ANDA Products for the treatment of pain is alleged to infringe the method claims (Compl. ¶¶119-120).

  • Patent Identification: U.S. Patent No. 8,894,987, "TAMPER RESISTANT DOSAGE FORMS," issued November 25, 2014.

  • Technology Synopsis: This patent describes a process for preparing a dosage form by combining oxycodone hydrochloride with high molecular weight polyethylene oxide (PEO). The resulting "flattened cured shaped tablet" is characterized by a specific in-vitro dissolution release profile (Compl. ¶¶60, 128).

  • Asserted Claims: Independent claims 1, 38, and 60 (Compl. ¶128).

  • Accused Features: The manufacture of Defendant's Amended ANDA Products is alleged to be covered by the process claims (Compl. ¶128).

  • Patent Identification: U.S. Patent No. 8,894,988, "TAMPER RESISTANT DOSAGE FORMS," issued November 25, 2014.

  • Technology Synopsis: This patent claims a "cured tablet" comprising an extended-release matrix. The matrix contains at least one high molecular weight polyethylene oxide and oxycodone, conferring tamper-resistant characteristics (Compl. ¶¶61, 135).

  • Asserted Claims: Independent claims 1 and 6 (Compl. ¶135).

  • Accused Features: Defendant's Amended ANDA Products are alleged to be covered by the claims (Compl. ¶135).

  • Patent Identification: U.S. Patent No. 9,060,976, "PHARMACEUTICAL FORMULATION CONTAINING GELLING AGENT," issued June 23, 2015.

  • Technology Synopsis: The invention relates to an extended-release, abuse-deterrent dosage form comprising polyethylene oxide (PEO) and oxycodone. A key feature is that the core matrix is heated to melt at least a portion of the PEO, and polyethylene glycol (PEG) is applied onto the core (Compl. ¶¶62, 142).

  • Asserted Claims: Claim 1 (Compl. ¶142).

  • Accused Features: Defendant's Amended ANDA Products are alleged to be covered by the claims (Compl. ¶142).

  • Patent Identification: U.S. Patent No. 9,034,376, "PHARMACEUTICAL FORMULATION CONTAINING GELLING AGENT," issued May 19, 2015.

  • Technology Synopsis: This patent discloses a dosage form comprising a combination of polyethylene oxide and hydroxypropylmethylcellulose as gelling agents. This patent is not listed in the FDA's Orange Book for OxyContin® (Compl. ¶3).

  • Asserted Claims: Independent claim 1 (Compl. ¶149).

  • Accused Features: Defendant's Amended ANDA Products are alleged to be covered by the claims (Compl. ¶149).

  • Patent Identification: U.S. Patent No. 9,073,933, "OXYCODONE HYDROCHLORIDE HAVING LESS THAN 25 PPM 14-HYDROXYCODEINONE," issued July 7, 2015.

  • Technology Synopsis: This patent, from the same family as the '799 patent, claims an oxycodone hydrochloride composition having less than 25 ppm of the 14-hydroxycodeinone impurity (Compl. ¶¶64, 156).

  • Asserted Claims: Independent claims 1 and 16 (Compl. ¶156).

  • Accused Features: Defendant's Amended ANDA Products are alleged to be covered by the claims (Compl. ¶156).

III. The Accused Instrumentality

Product Identification

  • Defendant's Amended ANDA Products, which are generic versions of Purdue's OxyContin® extended-release oxycodone hydrochloride tablets (Compl. ¶2).

Functionality and Market Context

  • The accused products are proposed generic drugs submitted to the FDA for approval under ANDA No. 203235 (Compl. ¶¶1-2). The ANDA seeks approval to market the products in 10 mg, 15 mg, 20 mg, 30 mg, 40 mg, 60 mg, and 80 mg dosage strengths (Compl. ¶2). The act of infringement alleged is the submission of the ANDA itself under 35 U.S.C. § 271(e)(2)(A), which seeks approval to engage in the future commercial manufacture, use, or sale of a drug claimed in a patent (Compl. ¶¶70, 76).
    No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not contain a claim chart or detailed, element-by-element infringement allegations. The allegations are made at a high level, stating that the Defendant's Amended ANDA Products, or their manufacture or use, are covered by one or more claims of the patents-in-suit. This is typical in ANDA litigation where infringement is a statutory act based on the ANDA filing for a product that is bioequivalent to the branded drug.

U.S. Patent No. 7,674,799 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
an oral dosage form The Defendant's Amended ANDA Products are described as oral dosage forms seeking approval as generic versions of OxyContin®. ¶2; ¶71 col. 29:55-57
comprising from about 5 mg to about 320 mg of oxycodone hydrochloride The Amended ANDA seeks approval for dosage strengths of 10, 15, 20, 30, 40, 60, and 80 mg, which fall within the claimed range. ¶2; ¶71 col. 29:58-59
having less than 25 ppm 14-hydroxycodeinone The complaint alleges that the Amended ANDA Products are covered by claims reciting this limitation. ¶71 col. 29:59-60
wherein at least a portion of the 14-hydroxycodeinone is derived from 8α,14-dihydroxy-7,8-dihydrocodeinone The complaint alleges that the Amended ANDA Products are covered by claims reciting this limitation. ¶71 col. 29:60-63

U.S. Patent No. 7,674,800 Infringement Allegations

Claim Element (from Independent Claim 38) Alleged Infringing Functionality Complaint Citation Patent Citation
An oxycodone hydrochloride composition The Amended ANDA Products are described as oxycodone hydrochloride compositions. ¶2; ¶77 col. 31:40-41
having less than 25 ppm 14-hydroxycodeinone, The complaint alleges on information and belief that the Amended ANDA Products meet this limitation. ¶77 col. 31:42-43
prepared by a process comprising hydrogenating a 14-hydroxycodeinone composition... The complaint alleges on information and belief that the Amended ANDA Products are prepared by the claimed process. ¶77 col. 31:43-46

Identified Points of Contention

  • Scope Questions: For the abuse-deterrence patents (e.g., ’383, ’060, ’888), a primary question will be whether the specific formulation disclosed in Amneal's confidential ANDA meets the quantitative physical limitations of the claims, such as a "breaking strength of at least 500 N" ('383 Patent, col. 30:1-3) or the viscosity imparted by a "gelling agent" ('888 Patent, col. 25:22-26).
  • Technical Questions: For the product-by-process claims of the ’800 Patent, the analysis will depend on whether Amneal's manufacturing method, as detailed in its ANDA, includes the step of "hydrogenating a 14-hydroxycodeinone composition" as claimed ('800 Patent, col. 31:44-45). The complaint makes this allegation based on "information and belief," suggesting discovery into Amneal's process will be required (Compl. ¶77).

V. Key Claim Terms for Construction

  • The Term: "prepared by a process" (from claim 38 of the ’800 Patent)
  • Context and Importance: This phrase makes the claim a "product-by-process" claim. Its construction is critical because infringement requires proof that the accused product was made using the claimed process, not just that it has the same chemical composition as the end product. Practitioners may focus on this term because it raises the evidentiary bar for Plaintiffs, who must obtain discovery on Defendant's confidential manufacturing process and demonstrate it falls within the scope of the process steps recited in the patent's claims.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent states that the process can be carried out in various solvents and with different catalysts, which may support an argument that the claim covers any hydrogenation process that achieves the claimed result ('800 Patent, col. 7:51-67).
    • Evidence for a Narrower Interpretation: The detailed description provides specific examples of hydrogenation performed under particular conditions of temperature, pressure, and duration ('800 Patent, Examples 1-3). This could support an argument that the claim is limited to processes using conditions similar to those specifically disclosed.

VI. Other Allegations

Indirect Infringement

  • The complaint alleges that if the FDA approves the ANDA, Defendant's commercial activities will induce and contribute to infringement by healthcare providers and patients (Compl. ¶¶72, 84, 90, 96, 109). The basis for inducement is the allegation that Defendant's proposed product label will instruct users to administer the drug in a manner that directly infringes method-of-use claims (e.g., '741 Patent at Compl. ¶120).

Willful Infringement

  • The complaint does not use the term "willful," but for several of the later-issued patents, it alleges that Defendant has been aware of the patent's existence and has "no reasonable basis for believing" its products would not infringe, thereby rendering the case "exceptional" under 35 U.S.C. § 285 (Compl. ¶¶124, 131, 138, 145, 152, 159). For the '060 and '741 patents, it alleges knowledge since at least the date of the Notice Letter (Compl. ¶¶102, 121). These allegations form a basis for seeking enhanced damages and attorneys' fees.

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

  • A central issue will be one of procedural preclusion: given that district courts have previously found claims of six of the asserted patents invalid, will those judgments collaterally estop Plaintiffs from reasserting them here, or can Plaintiffs successfully argue they lacked a "full and fair opportunity to litigate," a question that may influence the scope and focus of the present litigation?
  • A key technical question will be one of process and proof: for the product-by-process claims (e.g., in the ’800 patent) and the claims tied to specific manufacturing methods (e.g., "convection cured" in the '741 patent), what evidence will discovery of Amneal's confidential ANDA reveal about its manufacturing process, and does that process fall within the scope of the asserted claims?
  • A third core issue will be one of physical properties: for the portfolio of abuse-deterrence patents, discovery will be needed to determine if Amneal's proposed generic product, designed to be bioequivalent to OxyContin®, also possesses the specific physical and chemical properties claimed as inventive, such as high breaking strength and gelling characteristics upon tampering.