DCT

5:24-cv-00284

Purdue Pharma LP v. Accord Healthcare Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 5:24-cv-00284, E.D.N.C., 05/21/2024
  • Venue Allegations: Venue is alleged to be proper as Defendants are incorporated in the State of North Carolina and have a primary place of business within the Eastern District of North Carolina.
  • Core Dispute: Plaintiff alleges that Defendant’s Abbreviated New Drug Application (ANDA) to market a generic version of OxyContin® infringes four patents related to tamper-resistant, extended-release opioid dosage forms.
  • Technical Context: The technology concerns pharmaceutical formulations of the opioid oxycodone designed to deter abuse by resisting crushing and preventing rapid release of the active agent when exposed to alcohol.
  • Key Procedural History: The complaint details a history of litigation between the parties concerning the same ANDA but different patents. In Purdue v. Accord I, a Delaware court found several related patents invalid for obviousness, a decision now on appeal to the Federal Circuit. In Purdue v. Accord II, a bench trial was held in Delaware regarding two other related patents, with a decision pending. The patents-in-suit in the current action are newly issued.

Case Timeline

Date Event
2006-08-25 Earliest Priority Date for all Patents-in-Suit
2020-08-25 Defendant files ANDA No. 213564 (on or before this date)
2020-10-08 Plaintiff files Purdue v. Accord I in D. Del.
2022-07-08 Plaintiff files Purdue v. Accord II in D. Del.
2023-04-11 D. Del. court finds patents in Purdue v. Accord I invalid
2023-11-28 ’472 Patent Issued
2024-02-20 ’055 Patent Issued
2024-03-26 ’225 Patent Issued
2024-04-23 ’056 Patent Issued
2024-05-21 Complaint Filed

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

U.S. Patent No. 11,826,472 - "TAMPER RESISTANT DOSAGE FORMS"

  • Patent Identification: U.S. Patent No. 11,826,472 (“TAMPER RESISTANT DOSAGE FORMS”), issued November 28, 2023. (Compl. ¶37).

The Invention Explained

  • Problem Addressed: The patent’s background section describes the problem of prescription drug abuse, particularly with controlled-release opioid formulations. Abusers may crush tablets for immediate release or use solvents like ethanol to extract the opioid for oral or parenteral administration, which can lead to overdose. (’472 Patent, col. 1:15-36).
  • The Patented Solution: The invention is a solid oral dosage form comprising an opioid analgesic within an extended-release matrix of high molecular weight polyethylene oxide (PEO). This composition is designed to be difficult to crush and resistant to alcohol extraction. A key manufacturing step is "curing" the dosage form at an elevated temperature, which the patent describes as imparting these tamper-resistant qualities. (’472 Patent, Abstract; col. 2:50-67).
  • Technical Importance: The technology provides a formulation intended to deter common methods of opioid abuse, addressing a significant public health concern. (’472 Patent, col. 1:31-36).

Key Claims at a Glance

  • The complaint asserts independent claim 1. (Compl. ¶49).
  • Essential elements of independent claim 1 include:
    • A solid oral extended release dosage form comprising an extended release matrix with an active agent and a specific high molecular weight polyethylene oxide (PEO).
    • A specific dissolution rate profile when measured in simulated gastric fluid (SGF) at different time points (1, 2, 4, and 6 hours).
    • A specific in-vitro dissolution rate profile in SGF containing 40% ethanol, which must not deviate more than 20% from the rate in SGF without ethanol.
    • A requirement that the dosage form is "cured" at a specific temperature range (68° C. to 85° C.) for a specific duration (30 minutes to 4 hours).
    • Specific physical properties, including resistance to breaking under a defined force in a hardness test and resistance to cracking in an indentation test.
    • Specific pharmacokinetic properties, including a mean tmax and Cmax of oxycodone.
    • A limitation on the level of 14-hydroxycodeinone, a known impurity.
    • The inclusion of a second, lower molecular weight PEO in the matrix.
  • The complaint reserves the right to assert claims dependent on claim 1. (Compl. ¶49).

U.S. Patent No. 11,904,055 - "TAMPER RESISTANT DOSAGE FORMS"

  • Patent Identification: U.S. Patent No. 11,904,055 (“TAMPER RESISTANT DOSAGE FORMS”), issued February 20, 2024. (Compl. ¶38).

The Invention Explained

  • Problem Addressed: The patent addresses the same problem of opioid abuse as the ’472 Patent. (’055 Patent, col. 1:20-41).
  • The Patented Solution: This patent claims a process for preparing the tamper-resistant dosage form. The claimed process involves the steps of combining PEO and oxycodone hydrochloride, shaping the composition, and crucially, "curing" the formulation at a temperature between approximately 68° C. and 85° C. for about 30 minutes to 4 hours. This curing step is described as essential for creating the final dosage form with its abuse-deterrent properties. (’055 Patent, Abstract; col. 2:54-col. 3:5).
  • Technical Importance: The invention protects the specific manufacturing method used to create the tamper-resistant product, distinct from protecting the product composition itself.

Key Claims at a Glance

  • The complaint asserts independent claim 1. (Compl. ¶58).
  • Essential elements of independent claim 1 include:
    • A process of preparing a solid oral extended release dosage form.
    • A "combining" step involving polyethylene oxide and oxycodone hydrochloride.
    • A "shaping" step to form an extended release matrix formulation.
    • A "curing" step at a temperature of about 68° C. to 85° C. for about 30 minutes to 4 hours.
    • The claim further defines the resulting dosage form by its composition (including specific PEO molecular weights and amounts) and its functional properties (dissolution rates, hardness, pharmacokinetic profile, and impurity levels), which mirror those recited in claim 1 of the ’472 Patent.
  • The complaint reserves the right to assert claims dependent on claim 1. (Compl. ¶58).

U.S. Patent No. 11,938,225 - "TAMPER RESISTANT DOSAGE FORMS"

  • Patent Identification: U.S. Patent No. 11,938,225 (“TAMPER RESISTANT DOSAGE FORMS”), issued March 26, 2024. (Compl. ¶39).
  • Technology Synopsis: This patent claims a method of treating pain by orally administering a solid oral extended-release dosage form. The claimed dosage form is defined by the same set of compositional, dissolution, curing, and physical properties as the dosage form claimed in the ’472 patent. (Compl. ¶68).
  • Asserted Claims: Independent claim 1. (Compl. ¶68).
  • Accused Features: The administration of Accord’s ANDA Products by healthcare providers and patients for the treatment of pain, which Plaintiff alleges will be instructed by the product’s proposed label. (Compl. ¶¶69, 70).

U.S. Patent No. 11,964,056 - "TAMPER RESISTANT DOSAGE FORMS"

  • Patent Identification: U.S. Patent No. 11,964,056 (“TAMPER RESISTANT DOSAGE FORMS”), issued April 23, 2024. (Compl. ¶40).
  • Technology Synopsis: This patent claims a solid oral extended-release dosage form containing specific excipients (magnesium stearate, butylated hydroxytoluene) and PEO. A distinguishing feature is that the dosage form is defined as being "expanded upon curing, as measured by a decrease in density of at least about 1.0%," providing a specific physical metric for the curing process. (Compl. ¶¶86-88).
  • Asserted Claims: Independent claims 1, 19, and 20. (Compl. ¶¶86-88).
  • Accused Features: The composition of Accord’s ANDA Products, which are alleged to contain the claimed matrix and excipients and to be manufactured using a process that results in the claimed expansion upon curing. (Compl. ¶¶86-88).

III. The Accused Instrumentality

Product Identification

  • Defendants' proposed generic versions of OxyContin® oral tablets in 10, 15, 20, 30, 40, 60, and 80 mg dosage strengths, as described in Abbreviated New Drug Application (ANDA) No. 213564. (Compl. ¶¶2, 5).

Functionality and Market Context

  • The complaint, filed under the Hatch-Waxman Act, is based on the filing of the ANDA itself, which is a technical act of infringement. (Compl. ¶44). The complaint does not provide specific details on the functionality or manufacturing process of the Defendants' proposed products beyond alleging, upon information and belief, that the products and the process for making them will meet all limitations of the asserted claims. (Compl. ¶¶49, 58, 68, 86). The accused products are intended to be generic equivalents to Purdue’s OxyContin®, a widely prescribed opioid analgesic for long-term pain treatment. (Compl. ¶¶4, 5, 13). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not provide a claim chart or detailed, element-by-element mapping of the accused products to the asserted claims. Instead, it recites the full text of the independent claim(s) for each patent and makes a general allegation, "on information and belief," that the Defendants' ANDA Products (or the process for making them, or the method of using them) are covered by the claim(s). (Compl. ¶¶49, 58, 68, 86-88).

Identified Points of Contention

  • Given the highly specific and numerous limitations in the asserted claims, several potential points of dispute may arise.
    • Technical Questions: A primary factual dispute will likely be whether the product described in Accord’s confidential ANDA actually possesses all of the claimed properties. For the product claims (’472 and ’056 Patents), this raises several evidentiary questions:
      • Does the ANDA product's formulation meet the specific PEO molecular weight ranges and weight percentages required by the claims?
      • What evidence does the ANDA provide that the proposed generic product will exhibit the precise multi-point dissolution profiles claimed, both in standard gastric fluid and in fluid containing 40% ethanol?
      • Will the product, as manufactured, meet the quantitative requirements for breaking strength ("does not break" under ~439 N) and indentation resistance ("resists a work of at least about 0.06 J without cracking")?
    • Scope Questions: For the process claims (’055 Patent), the central dispute will likely be one of claim scope and infringement:
      • Does the manufacturing process described in Accord’s ANDA include a step that meets the definition of "curing" as that term is used in the patent, specifically by subjecting the formulation to a temperature between 68° C. and 85° C. for 30 minutes to 4 hours? A key question for the court will be whether standard drying or other heat-treatment steps in the ANDA process fall within the scope of the claimed "curing" step.

V. Key Claim Terms for Construction

The Term

  • "curing" / "cured"

Context and Importance

  • This term appears in the independent claims of the ’472, ’055, and ’225 patents and is central to the patented technology. The patents teach that this "curing" step imparts the novel tamper-resistant properties. The dispute will likely center on whether the heating step(s) in Accord's manufacturing process, as described in its ANDA, constitute "curing" within the meaning of the patents, or if they are merely conventional drying steps that fall outside the claim scope.

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: The specifications may support a broader, functional definition. For instance, the ’472 Patent states that curing involves subjecting the formulation to a temperature "at least as high as the softening temperature of the high molecular weight polyethylene oxide," which "causes the polyethylene oxide particles to at least adhere to each other or even to fuse." (’472 Patent, col. 17:46-55). This language focuses on the condition and result, which could be argued to cover any heating process that achieves this effect.
  • Evidence for a Narrower Interpretation: The specifications also provide specific examples with defined temperature and time parameters (e.g., curing at 70-75° C. for 6 to 9 hours, or at 73° C. for 3 hours). (’472 Patent, Example 2; Example 8). A defendant may argue that these specific embodiments limit the term "curing" to a process that is distinct from conventional manufacturing steps and requires the specific conditions and intent described in the patent's examples.

VI. Other Allegations

Indirect Infringement

  • For the method-of-use ’225 Patent, the complaint alleges induced infringement. It asserts that Accord’s proposed product label will instruct healthcare providers and patients to administer the generic product for the treatment of pain, thereby inducing direct infringement of the claimed method. (Compl. ¶¶70, 71, 78).

Willful Infringement

  • The complaint does not use the word "willful" but alleges that Defendants have been aware of the existence of the patents-in-suit and have no reasonable basis for believing their ANDA Products will not infringe. (Compl. ¶¶54, 64, 82, 93). This forms the basis for a request that the case be declared "exceptional" under 35 U.S.C. § 285, which allows for the award of attorneys' fees. (Compl. p. 21). The allegations are based on knowledge dating from at least the issue date of each patent. (Compl. ¶50, 59, 73, 89).

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

  • A core issue will be one of claim construction and infringement: Does the manufacturing process detailed in Accord’s confidential ANDA include a step that constitutes "curing" within the specific temperature and time parameters required by the claims, or is it a conventional manufacturing step that falls outside the scope of the patented process? The case will likely involve significant expert testimony on the meaning of this term in the context of pharmaceutical manufacturing.
  • A key evidentiary question will be one of technical proof: Can Purdue demonstrate, based on the contents of the ANDA submission, that Accord's proposed generic product will necessarily meet every one of the numerous and highly specific quantitative limitations of the asserted product claims, including multi-point dissolution rates (with and without alcohol), physical hardness and cracking resistance metrics, and in-vivo pharmacokinetic parameters?
  • A central legal and factual question for the method-of-use claim will be inducement: Assuming the product infringes the composition claims, does the language of Accord's proposed product labeling provide sufficient instruction or encouragement for healthcare providers and patients to administer the drug in a way that directly infringes the claimed method of treating pain?