DCT
1:17-cv-00210
Purdue Pharma LP v. Amneal Pharma LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Purdue Pharma L.P., Purdue Pharmaceuticals L.P., The P.F. Laboratories, Inc., and Rhodes Technologies (Delaware, New Jersey, Rhode Island)
- Defendant: Amneal Pharmaceuticals, LLC (Delaware)
- Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP; Jones Day
- Case Identification: 1:17-cv-00210, D. Del., 03/01/2017
- Venue Allegations: Venue is based on Defendant being a Delaware limited liability company registered to conduct business in the state, with systematic and continuous contacts with Delaware.
- Core Dispute: Plaintiff alleges that Defendant’s Abbreviated New Drug Application (ANDA) seeking to market generic versions of OxyContin® constitutes an act of infringement of three patents related to tamper-resistant pharmaceutical formulations and oxycodone compositions.
- Technical Context: The technology concerns formulations for extended-release opioids designed to deter abuse by making the tablets physically resistant to crushing or chemical extraction.
- Key Procedural History: The action was initiated under the Hatch-Waxman Act following Defendant’s submission of a Paragraph IV certification alleging that Plaintiff’s patents are invalid, unenforceable, or not infringed by its proposed generic product. The complaint notes prior litigation between the parties concerning the same ANDA and other patents covering OxyContin®.
Case Timeline
| Date | Event |
|---|---|
| 2004-03-30 | U.S. Patent No. 9,522,919 Priority Date |
| 2006-08-25 | U.S. Patent Nos. 9,492,392 & 9,492,393 Priority Date |
| 2011-09-27 | Defendant's ANDA No. 203235 filed |
| 2016-11-15 | U.S. Patent Nos. 9,492,392 & 9,492,393 issued |
| 2016-12-20 | U.S. Patent No. 9,522,919 issued |
| 2017-01-16 | Defendant sent "Notice of Paragraph IV Certification" Letter |
| 2017-03-01 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,492,392 - "TAMPER RESISTANT DOSAGE FORMS"
- Patent Identification: U.S. Patent No. 9,492,392, titled "TAMPER RESISTANT DOSAGE FORMS," issued November 15, 2016 (Compl. ¶20).
- The Invention Explained:
- Problem Addressed: The patent’s background describes the problem of opioid abuse, where individuals tamper with extended-release dosage forms (e.g., by crushing or dissolving) to release the full dose of the drug at once for immediate effect (’392 Patent, col. 1:24-37).
- The Patented Solution: The invention is a pharmaceutical tablet that is resistant to such tampering. The solution lies in a manufacturing process where a matrix containing the opioid and a high molecular weight polymer (polyethylene oxide) is first shaped by compression, and then subjected to a "curing" step using heated air without compression. This thermal curing process hardens the tablet, making it significantly more difficult to crush or extract the active ingredient for abuse ('392 Patent, Abstract; col. 16:16-23).
- Technical Importance: This two-step process provides a method to create a physically robust, abuse-deterrent oral dosage form that maintains its extended-release characteristics.
- Key Claims at a Glance:
- The complaint asserts independent claim 1 (Compl. ¶32).
- The essential elements of independent claim 1 include:
- A cured shaped pharmaceutical tablet comprising at least a first compression shaped and then air cured matrix,
- wherein said curing is without compression, by heated air having a temperature of at least about 62° C for a duration of at least about 5 minutes,
- said matrix comprising oxycodone or a pharmaceutically acceptable salt thereof in combination with at least one high molecular weight polyethylene oxide,
- having an approximate molecular weight selected from the group consisting of 4,000,000, 7,000,000, and a combination thereof.
- The complaint reserves the right to assert various dependent claims (Compl. ¶32).
U.S. Patent No. 9,492,393 - "TAMPER RESISTANT DOSAGE FORMS"
- Patent Identification: U.S. Patent No. 9,492,393, titled "TAMPER RESISTANT DOSAGE FORMS," issued November 15, 2016 (Compl. ¶21).
- The Invention Explained:
- Problem Addressed: Similar to its family member, the ’392 patent, this patent addresses the abuse of opioid medications by tampering with their dosage forms to achieve rapid drug release (’393 Patent, col. 1:24-37).
- The Patented Solution: The patent claims a method of treating pain by administering the tamper-resistant tablet. The tablet itself is identical in concept to that described in the ’392 patent, being formed through a process of compression followed by thermal curing without pressure to impart physical resistance to abuse ('393 Patent, Abstract; col. 16:16-23).
- Technical Importance: By claiming the method of use, the patent provides a basis to allege infringement against parties who encourage or instruct others (e.g., patients and physicians via a drug label) to use the tamper-resistant dosage form for pain treatment.
- Key Claims at a Glance:
- The complaint asserts independent claim 1 (Compl. ¶39).
- The essential elements of independent claim 1 include:
- A method of treating pain comprising administering to a patient in need thereof a pharmaceutical tablet,
- comprising at least a first compression shaped and then air cured matrix,
- wherein said curing is without compression by heated air having a temperature of at least about 62° C for a duration of at least about 5 minutes,
- said matrix comprising oxycodone or a pharmaceutically acceptable salt thereof in combination with at least one high molecular weight polyethylene oxide,
- having, based on rheological measurements, an approximate molecular weight selected from the group consisting of 4,000,000, 7,000,000, and a combination thereof.
- The complaint reserves the right to assert various dependent claims (Compl. ¶39).
U.S. Patent No. 9,522,919 - "OXYCODONE COMPOSITIONS"
- Multi-Patent Capsule
- Patent Identification: U.S. Patent No. 9,522,919, titled "OXYCODONE COMPOSITIONS," issued December 20, 2016 (Compl. ¶22).
- Technology Synopsis: This patent addresses the presence of an impurity, 14-hydroxycodeinone, that can form during the synthesis of oxycodone. The invention provides an oxycodone hydrochloride composition characterized by a very low ratio of this specific impurity to the active ingredient, achieved through specific manufacturing and purification processes (’919 Patent, Abstract; col. 2:9-14).
- Asserted Claims: Independent claims 1, 4, 12, and 18 are asserted (Compl. ¶52).
- Accused Features: The complaint alleges that Defendant's proposed generic products are, or are manufactured from, an oxycodone hydrochloride composition that meets the claimed purity limitation, specifically that the ratio of the impurity 8α,14-dihydroxy-7,8-dihydrocodeinone to oxycodone hydrochloride is 0.04% or less (Compl. ¶52).
III. The Accused Instrumentality
Product Identification
- Defendant’s proposed generic oxycodone hydrochloride extended-release tablets, which are the subject of Abbreviated New Drug Application (ANDA) No. 203235 (Compl. ¶¶ 1-2).
Functionality and Market Context
- The accused products are intended to be generic equivalents of Purdue’s OxyContin®, an extended-release opioid analgesic for the management of severe pain (Compl. ¶¶ 2, 5). The act of infringement alleged is the filing of the ANDA with the FDA to seek approval for commercial manufacture, use, and sale of these generic products in the United States, which is a statutory act of infringement under 35 U.S.C. § 271(e)(2)(A) (Compl. ¶31).
No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
9,492,392 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a cured shaped pharmaceutical tablet comprising at least a first compression shaped and then air cured matrix | The Defendant's Amended ANDA Products are alleged to be tablets comprising a matrix that is first compression shaped and then air cured. | ¶32 | col. 16:16-18 |
| wherein said curing is without compression, by heated air having a temperature of at least about 62° C for a duration of at least about 5 minutes | The manufacturing process for the ANDA products is alleged to include a curing step using heated air at the specified temperature and duration, without compression. | ¶32 | col. 17:1-6 |
| said matrix comprising oxycodone or a pharmaceutically acceptable salt thereof in combination with at least one high molecular weight polyethylene oxide | The matrix of the ANDA products is alleged to contain oxycodone and at least one high molecular weight polyethylene oxide. | ¶32 | col. 16:18-20 |
| having an approximate molecular weight selected from the group consisting of 4,000,000, 7,000,000, and a combination thereof | The polyethylene oxide used in the ANDA products is alleged to have a molecular weight within the claimed range. | ¶32 | col. 8:13-16 |
9,492,393 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A method of treating pain comprising administering to a patient in need thereof a pharmaceutical tablet | The proposed label for Defendant's Amended ANDA Products allegedly instructs healthcare providers and patients to administer the tablet for the treatment of pain. | ¶39, ¶44 | col. 36:34-39 |
| comprising at least a first compression shaped and then air cured matrix...wherein said curing is without compression by heated air having a temperature of at least about 62° C for a duration of at least about 5 minutes | The tablet to be administered is alleged to be manufactured using the claimed compression and subsequent thermal curing process. | ¶39, ¶44 | col. 17:1-6 |
| said matrix comprising oxycodone...in combination with at least one high molecular weight polyethylene oxide having...an approximate molecular weight selected from the group consisting of 4,000,000, 7,000,000, and a combination thereof | The tablet to be administered is alleged to contain a matrix with the specified components and molecular weights. | ¶39, ¶44 | col. 8:13-16 |
- Identified Points of Contention:
- Scope Questions: For the '392 and '393 patents, a central question may be whether Defendant's manufacturing process, as described in its confidential ANDA, falls within the scope of the claim term "curing is without compression". The litigation may explore whether any incidental pressure during Defendant's heating step constitutes "compression" as contemplated by the patents.
- Technical Questions: A primary factual dispute for the '392 and '393 patents will concern the specifics of Defendant's manufacturing process. For the '919 patent, the dispute will likely center on analytical chemistry evidence, raising the question of whether tests on Defendant's product confirm that the ratio of the specified impurity to oxycodone hydrochloride is "0.04% or less" as claimed.
V. Key Claim Terms for Construction
- The Term: "curing is without compression" (from claims of '392 and '393 patents)
- Context and Importance: This negative limitation is critical for distinguishing the patented invention from prior art manufacturing methods that might involve simultaneous application of heat and pressure. The definition will determine whether a defendant's process, which might involve incidental contact or the weight of tablets on one another in a batch, is infringing. Practitioners may focus on this term because it creates a potential non-infringement argument if any level of pressure is present during the defendant's heating step.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the invention as an improvement over "direct compression" tablet manufacturing, suggesting "without compression" could mean the absence of the high, deliberate force applied by a tablet press, rather than the absolute absence of any physical pressure ('392 Patent, col. 17:34-40).
- Evidence for a Narrower Interpretation: Embodiments describe the curing step as occurring while tablets are "spread onto a tray" in an oven or moving in a coating pan ('392 Patent, col. 43:53-56; col. 23:9-13). This language could support an interpretation requiring a complete lack of applied mechanical force, which a defendant might use to argue its process falls outside the claim scope.
VI. Other Allegations
- Indirect Infringement: The complaint alleges both contributory and induced infringement for the '392 product patent, stating the ANDA products are a "material part" of the invention (Compl. ¶¶ 33-34). For the '393 method patent, the complaint alleges active inducement, stating that Defendant's proposed label will "explicitly instruct Healthcare Providers and patients" to use the product in an infringing manner, and that Defendant will "aid, abet, urge, or encourage" infringement (Compl. ¶¶ 44, 47).
- Willful Infringement: For all three patents-in-suit, the complaint alleges that Defendant has been aware of their existence and has no reasonable basis to believe its products would not infringe, thereby rendering the case "exceptional" under 35 U.S.C. § 285 (Compl. ¶¶ 35, 48, 55). Knowledge is specifically alleged to exist since at least the date of Defendant's Notice Letter (Compl. ¶45).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of factual process equivalence: does the manufacturing process detailed in Defendant's confidential ANDA for its generic tablets meet the specific two-step "compression shaped and then air cured...without compression" limitations of the '392 and '393 patents, or does it utilize a fundamentally different technique for achieving tamper resistance?
- A key evidentiary question will be one of analytical composition: does the active pharmaceutical ingredient in Defendant’s proposed product, when tested via High-Performance Liquid Chromatography (HPLC) or equivalent methods, demonstrate a ratio of the impurity 8α,14-dihydroxy-7,8-dihydrocodeinone to oxycodone hydrochloride of 0.04% or less, as required by the claims of the '919 patent?
- A central legal question will be one of inducement: assuming infringement of the '393 method patent is found, does the language of Defendant's proposed drug label, which must mirror the innovator's label, provide sufficient evidence of specific intent to encourage or instruct infringement by patients and physicians?