DCT

1:20-cv-01362

Purdue Pharma LP v. Accord Healthcare Inc

Log In
Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:20-cv-01362, D. Del., 10/08/2020
  • Venue Allegations: Plaintiffs allege that venue is proper and that Defendants have agreed not to challenge it for the purposes of this action.
  • Core Dispute: Plaintiff alleges that Defendant’s Abbreviated New Drug Application (ANDA) for a generic version of the opioid analgesic OxyContin® constitutes an act of infringement of six patents related to tamper-resistant pharmaceutical formulations and high-purity oxycodone compositions.
  • Technical Context: The technology at issue involves methods to prevent the abuse of extended-release opioids and processes to reduce specific impurities during manufacturing, areas of significant public and market interest.
  • Key Procedural History: This is a Hatch-Waxman action initiated after Defendants filed ANDA No. 213564 and a Paragraph IV certification, alleging that Plaintiffs' Orange Book-listed patents are invalid, unenforceable, or will not be infringed. The complaint was filed within the 45-day statutory window following receipt of Defendants' notice letter, triggering an automatic 30-month stay on FDA approval of the ANDA.

Case Timeline

Date Event
2004-03-30 Earliest Priority Date for ’933 (Chapman), ’919, and ’434 Patents
2006-08-25 Earliest Priority Date for ’933 (Mannion), ’808, and ’886 Patents
2015-07-07 U.S. Patent No. 9,073,933 Issues
2016-12-20 U.S. Patent No. 9,522,919 Issues
2017-09-19 U.S. Patent Nos. 9,763,933 and 9,763,886 Issue
2017-10-03 U.S. Patent No. 9,775,808 Issues
2019-09-10 U.S. Patent No. 10,407,434 Issues
2020-08-25 Defendant Files ANDA No. 213564; Defendant sends Paragraph IV Notice Letter
2020-10-08 Complaint Filing Date

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

U.S. Patent No. 9,763,933 - "TAMPER RESISTANT DOSAGE FORMS"

  • Patent Identification: U.S. Patent No. 9,763,933, titled “TAMPER RESISTANT DOSAGE FORMS,” issued September 19, 2017 (Compl. ¶26).

The Invention Explained

  • Problem Addressed: The patent’s background section describes the problem of prescription drug abuse, specifically how abusers tamper with controlled-release opioid formulations by crushing, chewing, or dissolving them to achieve a rapid and dangerously high dose (’933 Patent, col. 1:21-36).
  • The Patented Solution: The invention is a solid, extended-release pharmaceutical tablet designed to thwart such abuse. It incorporates a high molecular weight polyethylene oxide (PEO) into a matrix with the opioid analgesic. This formulation makes the tablet very hard to crush and, when exposed to a solvent, causes it to form a viscous gel that is difficult to draw into a syringe for injection (’933 Patent, col. 2:25-31). A key part of the solution is a "curing" step, where the compressed tablet is heated for a period of time to achieve a high breaking strength, thereby enhancing its tamper-resistant properties (’933 Patent, col. 7:15-20).
  • Technical Importance: This technology provided a method for creating an opioid analgesic that delivers long-term pain relief as intended but is significantly more difficult to manipulate for abuse (’933 Patent, col. 1:37-45).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 11 (Compl. ¶39).
  • Independent Claim 1 includes the following essential elements:
    • A cured tablet comprising an extended release matrix,
    • wherein said tablet is obtained from a formulation comprising at least one polyethylene oxide having an approximate molecular weight of from 1,000,000 to 15,000,000, and oxycodone or a salt thereof,
    • wherein the cured tablet has a breaking strength of at least 100 N.
  • Independent Claim 11 includes the following essential elements:
    • A cured solid oral extended release pharmaceutical dosage form,
    • comprising an extended release matrix comprising oxycodone or a salt thereof, and at least one polyethylene oxide having an approximate molecular weight of at least 1,000,000,
    • wherein the dosage form has a breaking strength of at least 100 N when subjected to a breaking strength test.
  • The complaint alleges infringement of these claims and claims dependent therefrom (Compl. ¶39).

U.S. Patent No. 9,775,808 - "TAMPER RESISTANT DOSAGE FORMS"

  • Patent Identification: U.S. Patent No. 9,775,808, titled “TAMPER RESISTANT DOSAGE FORMS,” issued October 3, 2017 (Compl. ¶27).

The Invention Explained

  • Problem Addressed: The patent addresses the same problem of opioid abuse via tampering with extended-release dosage forms as the ’933 Patent (’808 Patent, col. 1:21-36).
  • The Patented Solution: The invention is also a tamper-resistant, extended-release dosage form using high molecular weight PEO. This patent further characterizes the invention by focusing on the physical changes that occur during the manufacturing process. It claims a pharmaceutical composition that is "expanded upon curing" and hardened, resulting in a tablet with specific physical properties, such as a defined hardness and a measurable decrease in density compared to an uncured version (’808 Patent, col. 23:45-61). This change in physical state is described as contributing to the tablet's abuse-deterrent characteristics.
  • Technical Importance: This patent provides an alternative way to define and claim the novel tamper-resistant formulation by focusing on measurable physical transformations (e.g., expansion, density change) that occur during the proprietary curing process (’808 Patent, col. 23:56-61).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 11 (Compl. ¶46).
  • Independent Claim 1 includes the following essential elements:
    • A pharmaceutical composition comprising at least one active agent and at least one high molecular weight PEO,
    • combined in a solid oral extended release dosage form by compression,
    • which is (i) without prior heating above the PEO's softening temperature, (ii) air cured at a temperature from about 70° C. to about 90° C., and (iii) hardened.
  • Independent Claim 11 depends from claim 1 and further requires:
    • The tablet is expanded upon curing, as measured by a change in tablet density of at least about 1%,
    • and the tablet has a hardness of at least about 439 N.
  • The complaint alleges infringement of these claims and claims dependent therefrom (Compl. ¶46).

U.S. Patent No. 9,763,886 - "TAMPER RESISTANT DOSAGE FORMS"

  • Patent Identification: U.S. Patent No. 9,763,886, titled “TAMPER RESISTANT DOSAGE FORMS,” issued September 19, 2017 (Compl. ¶28).
  • Technology Synopsis: This patent claims a method for producing the tamper-resistant dosage forms described in related patents. The invention is a multi-step manufacturing process that includes mixing an active agent with high molecular weight PEO, compressing the mixture into tablets, and "curing" the tablets by exposing them to heated air at or above the PEO's softening temperature for at least five minutes to achieve the desired physical resistance to tampering (’886 Patent, Abstract; Claim 1).
  • Asserted Claims: Independent claim 1 (Compl. ¶53).
  • Accused Features: The complaint alleges that the process of manufacturing Defendants' ANDA Products will infringe the claimed method (Compl. ¶53).

U.S. Patent No. 9,073,933 - "OXYCODONE HYDROCHLORIDE HAVING LESS THAN 25 PPM 14-HYDROXYCODEINONE"

  • Patent Identification: U.S. Patent No. 9,073,933, titled “OXYCODONE HYDROCHLORIDE HAVING LESS THAN 25 PPM 14-HYDROXYCODEINONE,” issued July 7, 2015 (Compl. ¶29).
  • Technology Synopsis: This patent addresses the technical problem of a specific impurity, 14-hydroxycodeinone, that can form during the synthesis of oxycodone and may be difficult to remove (’933 Patent (Chapman), col. 2:15-22). The invention covers both a process for preparing an oxycodone hydrochloride composition with less than 25 parts per million (ppm) of this impurity, and the resulting high-purity composition itself (’933 Patent (Chapman), Abstract).
  • Asserted Claims: Independent claims 1 and 16 (composition claims) and 10 (process claim) (Compl. ¶¶60, 62).
  • Accused Features: The complaint alleges infringement by both the process used to make the active pharmaceutical ingredient (API) in Defendants' ANDA Products and by the final product composition (Compl. ¶¶60, 62).

U.S. Patent No. 9,522,919 - "OXYCODONE COMPOSITIONS"

  • Patent Identification: U.S. Patent No. 9,522,919, titled “OXYCODONE COMPOSITIONS,” issued December 20, 2016 (Compl. ¶30).
  • Technology Synopsis: This patent is also directed at controlling impurities in oxycodone compositions. It claims an oxycodone hydrochloride composition where the ratio of a specific impurity, 8α,14-dihydroxy-7,8-dihydrocodeinone, to oxycodone HCl is 0.04% or less as measured by High-Performance Liquid Chromatography (HPLC) (’919 Patent, Abstract; Claim 1).
  • Asserted Claims: Independent claims 1, 12, and 18 (Compl. ¶69).
  • Accused Features: The composition of Defendants' ANDA Products is alleged to infringe (Compl. ¶69).

U.S. Patent No. 10,407,434 - "PROCESS FOR PREPARING OXYCODONE COMPOSITIONS"

  • Patent Identification: U.S. Patent No. 10,407,434, titled “PROCESS FOR PREPARING OXYCODONE COMPOSITIONS,” issued September 10, 2019 (Compl. ¶31).
  • Technology Synopsis: This patent claims a process for purifying oxycodone compositions to reduce the level of the same impurity identified in the ’919 patent: 8α, 14-dihydroxy-7,8-dihydrocodeinone. The invention is a multi-step purification process involving hydrogenation and recrystallization to achieve the desired level of purity (’434 Patent, Abstract; Claim 1).
  • Asserted Claims: Independent claim 1 (process) and dependent claim 20 (product-by-process) (Compl. ¶¶76, 78).
  • Accused Features: The complaint accuses the process for making the API used in the ANDA Products, as well as the final drug products themselves under a product-by-process theory (Compl. ¶¶76, 78).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Defendants' generic oxycodone hydrochloride extended-release tablets, which are the subject of ANDA No. 213564 ("Defendants' ANDA Products") (Compl. ¶¶1-2).

Functionality and Market Context

  • The accused products are proposed generic equivalents of Purdue's OxyContin®, intended for the management of severe, long-term pain (Compl. ¶¶2-3). They are formulated as extended-release tablets in various dosage strengths (10, 15, 20, 30, 40, 60, and 80 mg) (Compl. ¶2). The complaint alleges, on information and belief, that these products contain the specific chemical compositions and are manufactured using the specific processes claimed in the patents-in-suit, including the use of high molecular weight polyethylene oxide in a cured, extended-release matrix (Compl. ¶¶39, 46, 53) and having specific low levels of certain impurities (Compl. ¶¶62, 69, 78).
    No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

9,763,933 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A cured tablet comprising an extended release matrix... Defendants' ANDA Products are alleged to be cured tablets containing an extended release matrix. ¶39 col. 29:1-2
...wherein said tablet is obtained from a formulation comprising at least one polyethylene oxide having an approximate molecular weight of from 1,000,000 to 15,000,000... and oxycodone or a pharmaceutically acceptable salt thereof... The formulation for Defendants' ANDA Products allegedly includes oxycodone and at least one PEO with a molecular weight between 1,000,000 and 15,000,000. ¶39 col. 29:3-9
...wherein the cured tablet has a breaking strength of at least 100 N. Defendants' ANDA Products allegedly possess a breaking strength of at least 100 N. ¶39 col. 29:10-11

9,775,808 Patent Infringement Allegations

Claim Element (from Independent Claim 11) Alleged Infringing Functionality Complaint Citation Patent Citation
A pharmaceutical composition according to claim 1... Defendants' ANDA Products are alleged to be pharmaceutical compositions meeting the limitations of claim 1, which requires specific curing conditions. ¶46 col. 30:11-12
...wherein the tablet is expanded upon curing, as measured by a change in tablet density of at least about 1%... The accused products are alleged to expand and decrease in density during their manufacturing process. ¶46 col. 30:13-15
...and the tablet has a hardness of at least about 439 N. The accused products are alleged to have a hardness of at least 439 N. ¶46 col. 30:16-17
  • Identified Points of Contention:
    • Scope Questions: A primary question may be the proper construction of the term "cured." The patents describe this as a specific heating step that imparts tamper-resistant properties. Whether Defendants' manufacturing process, as described in its ANDA, includes a step that falls within the scope of this term will be a central issue.
    • Technical Questions: The infringement analysis will likely involve significant factual disputes requiring empirical evidence. For the formulation patents (’933 and ’808), a key question is whether testing of Defendants' ANDA Products confirms they possess the specific physical properties claimed, such as a "breaking strength of at least 100 N" or a "hardness of at least about 439 N." For the purity patents (’933-Chapman, ’919, ’434), the case will turn on analytical chemistry evidence to determine if the accused API and final drug product actually contain the claimed low levels of specific impurities.

V. Key Claim Terms for Construction

  • The Term: "cured" / "curing"

  • Context and Importance: This term appears in the independent claims of the tamper-resistance formulation patents (’933, ’808) and the method patent (’886). The definition of "curing" is critical because infringement of these patents depends on whether Defendants' manufacturing process includes a step that meets this definition. Practitioners may focus on this term because it appears to be the central inventive step distinguishing the patented formulations from prior art.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification suggests the functional result of the step is key, stating, "Without wanting to be bound by any theory, it is believed that the curing of the polyethylene oxide causes the polyethylene oxide particles to at least adhere to each other to form a matrix" (’886 Patent, col. 17:10-14). This language could support an argument that any heating process achieving this result constitutes "curing."
    • Evidence for a Narrower Interpretation: The specification provides specific examples and parameters, such as curing "at a temperature that is at least at the softening temperature of the high molecular weight polyethylene oxide for a curing time of at least about 5 minutes" (’886 Patent, Claim 1). This could support a narrower construction limited to thermal treatment meeting these specific time and temperature thresholds relative to the properties of the PEO.

  • The Term: "having less than 25 ppm of 14-hydroxycodeinone"

  • Context and Importance: This term from the ’933 (Chapman) patent is central to the purity-related infringement claims. While the numerical limit appears precise, the method of measurement can be a source of dispute in pharmaceutical patent cases.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The claims themselves do not specify a particular measurement technique, which may suggest that any scientifically accepted method for quantifying the impurity should suffice.
    • Evidence for a Narrower Interpretation: The patent's detailed description provides a specific HPLC-based analytical method for determining the level of 14-hydroxycodeinone (e.g., ’933 Patent (Chapman), Example 4, col. 27-30). A party could argue that this detailed disclosure implicitly defines the claim limitation, requiring that infringement be proven using this specific methodology or a demonstrably equivalent one.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon FDA approval, Defendants' commercial activities will induce infringement by end-users and contribute to infringement by others (Compl. ¶¶40, 47). For the ’886 method patent, the complaint alleges that Defendants' labeling and manufacturing process will induce infringement by patients, caregivers, and other manufacturers (Compl. ¶55). Knowledge is alleged based on Defendants' receipt of the Notice Letter (Compl. ¶¶40, 47, 63, 70).
  • Willful Infringement: The complaint alleges that for each asserted patent, Defendants have been aware of its existence and have "no reasonable basis for believing" their ANDA products would not infringe, thereby rendering the case "exceptional" under 35 U.S.C. § 285 (Compl. ¶¶42, 49, 56, 65, 72, 81).

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

  • A core issue will be one of process definition: Does Accord's manufacturing process, as detailed in its confidential ANDA, include a heating step that qualifies as "curing" under the proper construction of that term, or does it achieve tablet hardness and stability through means that fall outside the scope of the asserted patent claims?
  • A second key issue will be one of empirical proof: Will discovery and expert testing demonstrate that Accord's proposed generic tablets meet the specific, quantitative claim limitations related to physical tamper-resistance (e.g., breaking strength, hardness, density change) and chemical purity (e.g., impurity levels below 25 ppm)? The outcome will likely depend on a battle of competing analytical data.