DCT

1:17-cv-00392

Purdue Pharma LP v. Intellipharmaceutics Intl Inc

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:17-cv-00392, D. Del., 04/07/2017
  • Venue Allegations: The complaint asserts that Defendants have agreed not to contest venue in the District of Delaware.
  • Core Dispute: Plaintiffs allege that Defendants' New Drug Application for a generic version of the opioid analgesic OxyContin® constitutes an act of infringement of six U.S. patents related to abuse-deterrent formulations and high-purity compositions of oxycodone.
  • Technical Context: The patents relate to technologies designed to make extended-release opioid medications more difficult to abuse and to reduce potentially toxic impurities, a field of significant public health and commercial importance.
  • Key Procedural History: The complaint notes that certain claims of one patent-in-suit, the '060 patent, were previously found infringed but invalid for obviousness in litigation against other defendants (Endo Pharmaceuticals, Inc. et al. v. Amneal Pharmaceuticals, LLC et al.); that judgment is currently on appeal. Plaintiffs state their intent to seek a partial stay of the action with respect to the '060 patent pending the appeal's outcome.

Case Timeline

Date Event
2001-08-06 Priority Date for ’976 Patent
2003-08-06 Priority Date for ’060 Patent
2004-03-30 Priority Date for ’933 and ’919 Patents
2006-08-25 Priority Date for ’389 and ’391 Patents
2012-11-13 ’060 Patent Issued
2015-03-23 Trial began in Endo cases concerning ’060 Patent
2015-06-23 ’976 Patent Issued
2015-07-07 ’933 Patent Issued
2015-08-24 Judgment entered in Endo cases finding ’060 Patent claims invalid
2016-11-15 ’389 Patent Issued
2016-11-15 ’391 Patent Issued
2016-12-20 ’919 Patent Issued
2017-02-23 Defendants filed NDA No. 209653 (on or before this date)
2017-02-23 Defendants sent Paragraph IV Notice Letter
2017-04-07 Complaint Filed

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

U.S. Patent No. 9,060,976 - "PHARMACEUTICAL FORMULATION CONTAINING GELLING AGENT"

Issued June 23, 2015

The Invention Explained

  • Problem Addressed: The patent's background describes the abuse of oral opioid analgesics, particularly the practice of crushing dosage forms to extract the drug for subsequent parenteral (intravenous) injection to achieve a rapid euphoric effect, or "high" (’976 Patent, col. 1:17-30).
  • The Patented Solution: The invention incorporates a gelling agent into the drug formulation. When a potential abuser crushes the tablet and mixes it with a liquid for extraction, the gelling agent causes the mixture to form a viscous gel, which is difficult to draw into a syringe and inject, thereby deterring this specific route of abuse (’976 Patent, Abstract; col. 3:1-14).
  • Technical Importance: This technology represents a physical, rather than purely chemical, approach to abuse deterrence by altering the properties of the tampered dosage form to frustrate common methods of illicit preparation.

Key Claims at a Glance

  • Independent claim 1 is asserted in the complaint (Compl. ¶55).
  • Essential elements of Claim 1 include:
    • An extended release abuse deterrent dosage form comprising a core matrix.
    • The core matrix comprises polyethylene oxide (PEO) with a specific molecular weight range (from about 300,000 to 5,000,000 daltons) and oxycodone.
    • The core matrix is heated to melt at least a portion of the PEO.
    • Polyethylene glycol (PEG) is applied onto the core.
  • The complaint reserves the right to assert other claims (Compl. ¶56).

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

Issued July 7, 2015

The Invention Explained

  • Problem Addressed: The patent background identifies 14-hydroxycodeinone as a "potentially toxic" impurity and an alpha, beta, unsaturated ketone (ABUK) that may be formed during the synthesis of oxycodone from thebaine (’933 Patent, col. 1:50-55). Such impurities are a safety and regulatory concern.
  • The Patented Solution: The invention provides an oxycodone hydrochloride composition that is characterized by a very low level of the 14-hydroxycodeinone impurity—specifically, less than 25 parts per million (ppm). The patent describes processes that can achieve this level of purity (’933 Patent, Abstract; col. 2:37-45).
  • Technical Importance: This invention addresses the need for higher purity active pharmaceutical ingredients (APIs), potentially improving the safety profile of the final drug product by minimizing a specific, potentially genotoxic impurity.

Key Claims at a Glance

  • Independent claim 1 is asserted in the complaint (Compl. ¶62).
  • Essential elements of Claim 1 include:
    • An oxycodone hydrochloride composition.
    • Having less than 25 ppm of 14-hydroxycodeinone.
    • The composition also contains 8α,14-dihydroxy-7,8-dihydrocodeinone.
  • The complaint notes that various dependent claims are also infringed (Compl. ¶62).

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

Issued December 20, 2016

  • Technology Synopsis: This patent, like the ’933 Patent, relates to high-purity oxycodone compositions (Compl. ¶40). It claims a composition defined by a low ratio of a specific impurity (8α,14-dihydroxy-7,8-dihydrocodeinone) to the active ingredient, oxycodone hydrochloride, as measured by HPLC (Compl. ¶69).
  • Asserted Claims: The complaint asserts at least independent claim 1 (Compl. ¶69).
  • Accused Features: The accused feature is the composition of Defendants' NDA Products, which allegedly meets the claimed purity ratio (Compl. ¶69).

U.S. Patent No. 9,492,389 - "TAMPER RESISTANT DOSAGE FORMS"

Issued November 15, 2016

  • Technology Synopsis: This patent describes a method of creating a tamper-resistant tablet by shaping a matrix through compression and then curing it with heated air without compression (Compl. ¶41, ¶76). This process, involving specific temperature and duration parameters, results in a hardened, abuse-deterrent dosage form.
  • Asserted Claims: The complaint asserts at least independent claim 1 (Compl. ¶76).
  • Accused Features: The accused feature is Defendants' NDA Product, which is alleged to be a "cured shaped pharmaceutical tablet" manufactured according to the claimed process and containing the specified high molecular weight polyethylene oxide (Compl. ¶76).

U.S. Patent No. 9,492,391 - "TAMPER RESISTANT DOSAGE FORMS"

Issued November 15, 2016

  • Technology Synopsis: This patent appears closely related to the ’389 Patent, covering a "cured shaped pharmaceutical tablet" (Compl. ¶42). The infringement allegations recite a tablet formed by compression and then cured with heated air, without compression, and containing high molecular weight polyethylene oxide (Compl. ¶83).
  • Asserted Claims: The complaint asserts at least independent claim 1 (Compl. ¶83).
  • Accused Features: The accused feature is Defendants' NDA Product, which is alleged to be made by the process and have the composition claimed in the patent (Compl. ¶83).

U.S. Patent No. 8,309,060 - "ABUSE-PROOFED DOSAGE FORM"

Issued November 13, 2012

  • Technology Synopsis: This patent addresses abuse deterrence by creating a dosage form with high mechanical resistance to crushing (Compl. ¶43). The invention is a "thermoformed" dosage form containing a high molecular weight polymer that results in a tablet with a "breaking strength of at least 500 N," making it difficult to pulverize with conventional means (Compl. ¶90).
  • Asserted Claims: The complaint asserts at least independent claim 1 (Compl. ¶90).
  • Accused Features: The accused feature is Defendants' NDA Product, which is alleged to be an abuse-proofed, thermoformed dosage form possessing the claimed breaking strength (Compl. ¶90).

III. The Accused Instrumentality

Product Identification

  • Defendants' NDA Products, identified as a generic version of Purdue's OxyContin® and also referred to as Rexista® (Compl. ¶2, ¶27). The products are extended-release oxycodone hydrochloride tablets in 10, 15, 20, 30, 40, 60, and 80 mg dosage strengths (Compl. ¶2).

Functionality and Market Context

  • The accused products are opioid analgesics intended for the management of severe pain requiring long-term, around-the-clock treatment (Compl. ¶96). The complaint alleges that by filing NDA No. 209653 with the FDA, Defendants are seeking approval to commercially manufacture and sell these products in the United States (Compl. ¶2, ¶49). This action is a statutory act of infringement under 35 U.S.C. § 271(e)(2), which allows for patent litigation to be resolved before a generic drug enters the market (Compl. ¶54). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’976 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
an extended release abuse deterrent dosage form comprising a core matrix Defendants' NDA Products are alleged to be extended release, abuse deterrent dosage forms. ¶55 col. 29:1-2
said core matrix comprising PEO having a molecular weight of from about 300,000 daltons to about 5,000,000 daltons and oxycodone... The NDA Products allegedly comprise a core matrix with oxycodone and PEO within the specified molecular weight range. ¶55 col. 29:3-7
wherein the core matrix is heated to melt at least a portion of the PEO The complaint alleges that the NDA Products meet this limitation, implying their manufacturing process involves this heating step. ¶55 col. 29:8-9
and PEG applied onto the core The complaint alleges the NDA Products have PEG applied onto the core. ¶55 col. 29:10-11

Identified Points of Contention:

  • Scope Questions: The claim includes process limitations ("heated to melt," "applied onto the core"). A central question will be whether Defendants' manufacturing process for its NDA Products includes these specific steps. This raises a potential product-by-process claim construction issue.
  • Technical Questions: What evidence does the complaint provide that the accused products were manufactured using the claimed heating and application steps? The complaint makes this allegation on "information and belief," suggesting that proof will depend entirely on discovery into Defendants' confidential manufacturing processes.

’933 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An oxycodone hydrochloride composition Defendants' NDA Products are alleged to be oxycodone hydrochloride compositions. ¶62 col. 33:1-2
having less than 25 ppm of 14-hydroxycodeinone The NDA Products are alleged to contain the impurity 14-hydroxycodeinone at a level below 25 ppm. ¶62 col. 33:2-3
and 8α,14-dihydroxy-7,8-dihydrocodeinone The NDA Products are alleged to contain this specified substance. ¶62 col. 33:3-5

Identified Points of Contention:

  • Scope Questions: The dispute may turn on the methodology used to measure the impurity level. The court will need to determine if the measurement methods used to test Defendants' products are consistent with the methods disclosed and claimed in the patent.
  • Technical Questions: A primary factual question will be whether Defendants' NDA Products consistently contain less than 25 ppm of 14-hydroxycodeinone across all manufactured batches. Infringement may depend on the purity specifications in the NDA as well as the composition of actual product samples.

V. Key Claim Terms for Construction

For the ’976 Patent:

  • The Term: "heated to melt at least a portion of the PEO"
  • Context and Importance: This term describes a manufacturing step rather than a structural feature of the final product. Practitioners may focus on this term because its interpretation will determine whether infringement requires direct evidence of the accused manufacturing process or if it can be inferred from the final product's characteristics. The dispute may center on whether this product-by-process limitation is a valid basis for distinguishing the invention from the prior art and whether it limits the claim to products made by that specific process.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim uses the word "comprising," which is typically construed as open-ended, suggesting the heating step is merely one part of a potentially more complex process (’976 Patent, col. 29:2).
    • Evidence for a Narrower Interpretation: The detailed description provides specific examples of manufacturing processes involving heating steps, such as placing granulation in an oven at 70° C. (’976 Patent, col. 41:10-14). A defendant may argue that the term should be limited to these disclosed methods.

For the ’933 Patent:

  • The Term: "having less than 25 ppm of 14-hydroxycodeinone"
  • Context and Importance: This term defines the invention by its level of purity. Its construction is critical because infringement hinges on a quantitative chemical analysis. The central dispute will be factual—what is the impurity level in the accused product—but the legal framework for that analysis depends on how this term is construed, including the required precision and method of measurement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language is a straightforward ceiling ("less than 25 ppm"), which could be argued to apply to any composition that meets this threshold, regardless of how the purity was achieved.
    • Evidence for a Narrower Interpretation: The patent specification provides a detailed High Performance Liquid Chromatography (HPLC) method for measuring the impurity (’933 Patent, col. 31:44-col. 32:67). A party could argue that the claim term must be construed as being defined by this specific analytical method, potentially excluding results from different testing protocols.

VI. Other Allegations

Indirect Infringement

  • Plaintiffs allege that if the NDA is approved, Defendants' commercial activities will induce and contribute to the infringement of all patents-in-suit (e.g., Compl. ¶56, ¶63). For the '060 patent specifically, the complaint alleges that the proposed product label will explicitly instruct healthcare providers and patients to use the product in an infringing manner (i.e., administering the dosage form) (Compl. ¶96).

Willful Infringement

  • The complaint asserts that the case is "exceptional" under 35 U.S.C. § 285 for all asserted patents, alleging on "information and belief" that Defendants were aware of the patents and had no reasonable basis to believe their products would not infringe (e.g., Compl. ¶58, ¶65). For the '060 patent, knowledge is alleged from at least the date of receiving the Paragraph IV notice letter (Compl. ¶97).

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

  • A core issue will be one of evidentiary proof for process limitations: a majority of the asserted patents include claims defined by specific manufacturing steps (e.g., heating, curing, thermoforming). A key question for the case will be whether Plaintiffs can obtain and present sufficient evidence from Defendants' proprietary manufacturing processes to prove that the accused products are made in a way that meets these product-by-process limitations.
  • Another central issue will be the unconventional infringement theory of superior purity: for the '933 and '919 patents, Plaintiffs allege infringement because Defendants' product is too pure. The case will likely turn on a key factual question: does the accused product, as specified in its NDA and as produced in commercial-scale batches, consistently fall within the claimed low-impurity profiles when measured by the analytical methods detailed in the patents?
  • Finally, a significant procedural question will be the impact of prior invalidity: the '060 patent enters this litigation with a history of being found invalid in a separate case. A critical question will be what weight, if any, the court gives to the prior obviousness judgment, and whether Plaintiffs can successfully distinguish the present case or rely on the pending appeal to preserve the patent's enforceability.