DCT
1:17-cv-01421
Purdue Pharma LP v. Amneal Pharma LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Purdue Pharma L.P. (Delaware), Purdue Pharmaceuticals L.P. (Delaware), and Grünenthal GMBH (Germany)
- Defendant: Amneal Pharmaceuticals, LLC (Delaware)
- Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP; Jones Day; Finnegan, Henderson, Farabow, Garrett & Dunner, LLP
- Case Identification: 1:17-cv-01421, D. Del., 10/10/2017
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because the defendant, Amneal Pharmaceuticals, LLC, is a Delaware limited liability company and therefore resides in the judicial district.
- Core Dispute: Plaintiffs allege that Defendant’s submission of an Abbreviated New Drug Application (ANDA) to the FDA for a generic version of the opioid analgesic OxyContin® constitutes an act of infringement of three patents related to tamper-resistant and abuse-proofed pharmaceutical formulations.
- Technical Context: The technology concerns methods and compositions for creating extended-release opioid dosage forms that are physically hardened to resist crushing, tampering, and extraction for parenteral abuse.
- Key Procedural History: The complaint notes that this action is part of a larger, ongoing dispute between the parties concerning Amneal’s ANDA No. 203235. The complaint references three prior lawsuits filed by Purdue against Amneal involving numerous other patents listed in the FDA’s Orange Book for OxyContin®, indicating a protracted and multi-front litigation campaign to prevent generic entry.
Case Timeline
| Date | Event |
|---|---|
| 2002-06-17 | ’610 Patent Priority Date |
| 2006-08-25 | ’886 and ’933 Patents Priority Date |
| 2011-09-27 | Amneal ANDA No. 203235 first filed (on or before this date) |
| 2017-06-13 | ’610 Patent Issue Date |
| 2017-09-19 | ’886 Patent Issue Date |
| 2017-09-19 | ’933 Patent Issue Date |
| 2017-10-10 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,763,886 - "Tamper Resistant Dosage Forms"
- Patent Identification: U.S. Patent No. 9,763,886, "Tamper Resistant Dosage Forms," issued September 19, 2017. (Compl. ¶19).
The Invention Explained
- Problem Addressed: The patent addresses the problem of opioid abuse, wherein individuals tamper with controlled-release dosage forms (e.g., by crushing) to make the active ingredient immediately available for illicit administration, such as injection or insufflation. (’886 Patent, col. 1:19-35).
- The Patented Solution: The invention is a method for producing a solid oral extended-release pharmaceutical dosage form that is resistant to tampering. The method involves mixing an active agent with a high molecular weight polyethylene oxide (PEO), compressing the mixture into a shaped matrix, and then "curing" the matrix by exposing it to heated air for a specified duration at a temperature at or above the PEO's softening point. (’886 Patent, Abstract; col. 16:55-17:15). This curing step is described as creating a hardened, more tamper-resistant final product.
- Technical Importance: This process aims to create a dosage form that is significantly more difficult to crush or dissolve in solvents, thereby deterring common methods of abuse. (’886 Patent, col. 1:36-45).
Key Claims at a Glance
- The complaint asserts infringement of "one or more claims... including but not limited to independent claim 1." (Compl. ¶33).
- Independent Claim 1 of the ’886 Patent recites the essential elements of a method:
- mixing at least one active agent and at least one high molecular weight polyethylene oxide (PEO) having a molecular weight from 1 million to 15 million to provide a PEO composition;
- compressing the PEO composition to provide a plurality of shaped matrix compositions;
- curing the shaped matrix compositions by exposure to heated air at a curing temperature that is at least the softening temperature of the high molecular weight PEO for a curing time of at least about 5 minutes;
- cooling the cured matrix compositions;
- wherein the molecular weight of the PEO is based on rheological measurements;
- wherein the high molecular weight PEO comprises at least about 30% by weight of the dosage form;
- wherein the total weight of the dosage form excludes film coatings; and
- wherein the cured matrix is a solid oral dosage form providing extended release.
U.S. Patent No. 9,763,933 - "Tamper Resistant Dosage Forms"
- Patent Identification: U.S. Patent No. 9,763,933, "Tamper Resistant Dosage Forms," issued September 19, 2017. (Compl. ¶20).
The Invention Explained
- Problem Addressed: The patent targets the same problem of opioid abuse via tampering with controlled-release formulations as the ’886 Patent. (’933 Patent, col. 1:20-36).
- The Patented Solution: This patent claims the resulting composition from a process similar to that described in the ’886 Patent. The invention is a pharmaceutical composition containing an active agent and high molecular weight PEO, where the components are combined in a solid dosage form that is specifically described as being (i) compression shaped, (ii) air cured by heated air without compression, (iii) cooled, and (iv) hardened. (’933 Patent, Abstract; col. 1:46-59).
- Technical Importance: By claiming the composition itself, defined by its method of manufacture (a product-by-process claim), the patent seeks to protect the final tamper-resistant drug product, not just the method of making it. (’933 Patent, col. 1:40-45).
Key Claims at a Glance
- The complaint asserts infringement of "one or more claims... including but not limited to independent claim 1." (Compl. ¶40).
- Independent Claim 1 of the ’933 Patent recites the essential elements of a composition:
- at least one active agent;
- at least one high molecular weight PEO with a molecular weight from 1 million to 15 million;
- wherein the active agent and PEO are combined in a solid oral extended release dosage form that is (i) compression shaped, (ii) air cured by heated air, without compression, for at least about 5 minutes at a temperature above the PEO's softening temperature, (iii) cooled, and (iv) hardened;
- wherein the high molecular weight PEO comprises at least about 30% by weight of the dosage form;
- wherein the molecular weight of the PEO is based on rheological measurements; and
- wherein the total weight of the dosage form excludes film coatings.
U.S. Patent No. 9,675,610 - "Abuse-Proofed Dosage Form"
- Patent Identification: U.S. Patent No. 9,675,610, "Abuse-Proofed Dosage Form," issued June 13, 2017. (Compl. ¶21).
Technology Synopsis
- This patent addresses the problem of parenteral abuse by incorporating a viscosity-increasing agent into the dosage form. (’610 Patent, col. 2:15-25). When an abuser comminutes the tablet and attempts to extract the active ingredient with an aqueous liquid, the agent forms a viscous gel that is difficult to draw into a hypodermic needle and, if successfully injected into a further quantity of water (mimicking blood), remains as visible, cohesive "threads" instead of dispersing, thereby frustrating the attempted abuse and posing a risk of embolism. (’610 Patent, col. 2:26-36).
Asserted Claims & Accused Features
- Asserted Claims: Independent claim 1. (Compl. ¶47).
- Accused Features: The complaint alleges that Amneal's proposed generic products contain one or more active ingredients with abuse potential (oxycodone) and one or more viscosity-increasing agents that would form a gel with the claimed abuse-deterring properties upon an attempted extraction. (Compl. ¶47).
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are "Amneal's Amended ANDA Products," which are proposed generic versions of OxyContin® (oxycodone hydrochloride) extended-release tablets in 10, 15, 20, 30, 40, 60, and 80 mg dosage strengths. (Compl. ¶1).
Functionality and Market Context
- The complaint, characteristic of ANDA litigation, alleges infringement based on Defendant's submission of Abbreviated New Drug Application No. 203235 to the FDA. (Compl. ¶1). The act of filing an ANDA containing a "Paragraph IV" certification is a statutory act of infringement. (Compl. ¶32). The complaint does not describe the specific composition or manufacturing process of Amneal's proposed product, as that information is contained within the confidential ANDA submission. The allegations are based on the premise that the product for which Amneal seeks approval, if manufactured and sold, would embody the patented inventions. (Compl. ¶¶33, 40, 47). The accused products seek to compete as generic equivalents to Plaintiffs' branded OxyContin®, a major commercial opioid analgesic. (Compl. ¶1). No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
U.S. Patent No. 9,763,886 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a method of producing a plurality of solid oral extended release pharmaceutical dosage forms comprising the steps of: mixing at least one active agent, at least one high molecular weight polyethylene oxide (PEO)...to provide a PEO composition | The complaint alleges that the manufacture of Amneal's Amended ANDA Products will perform this step. | ¶33 | col. 16:55-61 |
| compressing the PEO composition to provide a plurality of shaped matrix compositions | The complaint alleges that the manufacture of Amneal's Amended ANDA Products will perform this step. | ¶33 | col. 16:62-63 |
| curing the shaped matrix compositions by exposure to heated air at a curing temperature that is at least the softening temperature of the high molecular weight PEO for a curing time of at least about 5 minutes | The complaint alleges that the manufacture of Amneal's Amended ANDA Products will perform this step. | ¶33 | col. 16:64-17:3 |
| cooling the cured matrix compositions | The complaint alleges that the manufacture of Amneal's Amended ANDA Products will perform this step. | ¶33 | col. 17:4-5 |
U.S. Patent No. 9,763,933 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a pharmaceutical composition comprising: at least one active agent; at least one high molecular weight polyethylene oxide (PEO) | The complaint alleges that Amneal's Amended ANDA Products are compositions comprising these elements. | ¶40 | col. 157:58-62 |
| wherein the active agent and high molecular weight PEO are combined in a solid oral extended release dosage form that is (i) compression shaped | The complaint alleges that Amneal's Amended ANDA Products possess this property. | ¶40 | col. 158:4-6 |
| (ii) air cured by heated air, without compression, for at least about 5 minutes at a temperature above the softening temperature of the high molecular weight PEO | The complaint alleges that Amneal's Amended ANDA Products are made by a process that imparts this property. | ¶40 | col. 158:7-11 |
| (iii) cooled, and (iv) hardened | The complaint alleges that Amneal's Amended ANDA Products possess these properties. | ¶40 | col. 158:12-13 |
Identified Points of Contention
- Technical Questions: The complaint does not provide specific evidence of how Amneal's manufacturing process or product composition meets the claim limitations. A central technical question will be whether the process detailed in Amneal's confidential ANDA includes a step that qualifies as "curing" as distinct from conventional drying. The specific parameters of time, temperature, and atmospheric conditions (e.g., "heated air") alleged to be used by Amneal will be critical.
- Scope Questions: The analysis will likely focus on whether routine thermal processing steps used in pharmaceutical tablet manufacturing fall within the scope of the term "curing." A key question is what objective physical or chemical transformation distinguishes the claimed "curing" process and the resulting "hardened" composition from a standard compressed tablet that has been dried to remove moisture.
V. Key Claim Terms for Construction
The Term: "curing"
- Context and Importance: This term is the central process step in the method of the ’886 Patent and defines the key characteristic of the composition in the ’933 Patent. Its construction is critical because it must be distinguished from conventional drying or heating steps in pharmaceutical manufacturing to maintain the patent's validity and scope. Practitioners may focus on this term because if it is construed broadly to cover any application of heat, it may read on prior art processes; if construed narrowly, it may not read on the accused process.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states that the purpose of curing is to "harden the tablets and to reduce the amount of drug released when the dosage form is tampered with," which could suggest that any thermal process achieving this functional result is "curing." (’886 Patent, col. 1:40-43).
- Evidence for a Narrower Interpretation: The specification provides specific examples with defined temperature ranges (e.g., "from about 60° C. to about 85° C.") and durations ("from about 5 minutes to about 24 hours"). (’886 Patent, col. 18:1-12). A defendant may argue that "curing" requires a specific thermal profile intended to cause inter-particle bonding or changes in the PEO matrix, rather than simply removing residual moisture.
The Term: "hardened"
- Context and Importance: This term describes the result of the "curing" process in the ’933 Patent and is essential for defining the allegedly novel, tamper-resistant property of the claimed composition. The parties will likely dispute the objective metric by which a dosage form is determined to be "hardened" under the claim.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification links "hardening" to the functional outcome of increased tamper resistance, such as resistance to crushing. (’933 Patent, col. 1:40-45). This could support a functional definition rather than a specific physical parameter.
- Evidence for a Narrower Interpretation: The patent's detailed description includes specific indentation and breaking strength tests used to characterize the tablets. (’933 Patent, col. 9:6-42; Figs. 20-35). A defendant may argue that "hardened" should be construed to require meeting a quantitative threshold of mechanical strength as measured by these tests, a threshold not necessarily met by the accused product.
VI. Other Allegations
Indirect Infringement
- The complaint alleges Amneal will induce infringement of the ’886 patent "through at least its labeling and manufacturing process," which will allegedly instruct patients, caregivers, and other manufacturers to use the infringing products. (Compl. ¶35). The complaint makes general allegations of inducement and contributory infringement for the ’933 and ’610 patents as well. (Compl. ¶¶41, 48).
Willful Infringement
- For all three patents-in-suit, the complaint alleges that Amneal has been aware of the patents and "has no reasonable basis for believing" its products will not infringe. (Compl. ¶¶36, 43, 50). This is alleged to render the case "exceptional" under 35 U.S.C. § 285, which could entitle Plaintiffs to enhanced damages and attorneys' fees if proven.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of technical definition and proof: does the manufacturing process described in Amneal’s confidential ANDA include a distinct thermal treatment step that meets the legal construction of "curing" as claimed in the patents, or is it a conventional drying process that falls outside the claim scope?
- A second key question will be one of product characterization: does Amneal's proposed generic product, as manufactured, possess the specific physical properties required by the claims, such as being "hardened" ('933 patent) or forming persistent gel "threads" upon attempted extraction ('610 patent)?
- Finally, the case may turn on a question of infringement under the Hatch-Waxman Act: given that infringement is based on the filing of the ANDA rather than an existing product, the dispute will depend on what the ANDA submission itself reveals about the proposed product and process, raising evidentiary challenges regarding the interpretation of that confidential regulatory filing.