DCT

1:19-cv-01340

Alkermes Pharma Ireland Ltd v. Luye Pharma Group Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-01340, D. Del., 07/17/2019
  • Venue Allegations: Venue is asserted based on Defendant Luye Pharma (USA) Ltd. being a Delaware corporation and other defendants allegedly conducting continuous and systematic business in the state. The complaint further alleges that the tortious act of infringement—filing a New Drug Application (NDA)—caused foreseeable harm to Plaintiffs in Delaware.
  • Core Dispute: Plaintiffs allege that Defendants' filing of an NDA for an extended-release risperidone injection constitutes an act of patent infringement under the Hatch-Waxman Act, as the product would infringe a patent protecting Plaintiffs' Risperdal Consta® drug if commercially launched.
  • Technical Context: The lawsuit concerns pharmaceutical formulations for long-acting injectable drugs, specifically addressing the technical challenge of ensuring that a high-concentration suspension of microparticles can be injected reliably without clogging the needle.
  • Key Procedural History: The complaint notes that Defendants previously challenged the validity of the patent-in-suit in two inter partes review (IPR) proceedings before the Patent Trial and Appeal Board (PTAB). One petition was denied institution, while the other proceeded to a final written decision where the PTAB found that Defendants had failed to prove the challenged claims were unpatentable.

Case Timeline

Date Event
2000-05-25 '061 Patent Priority Date
2003-10-29 Risperdal Consta® Original NDA Approval
2003-12-23 '061 Patent Issue Date
2009-05-15 Risperdal Consta® Expanded Indication Approval
2016-05-31 IPR Petitions Filed by Defendants
2016-11-20 PTAB Institution Decision on IPRs
2017-11-28 PTAB Final Written Decision Upholding Patentability
2019-06-04 Defendants' Paragraph IV Notice Letter Sent
2019-07-17 Complaint Filing Date

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

U.S. Patent No. 6,667,061 - “Preparation of Injectable Suspensions Having Improved Injectability”

The Invention Explained

  • Problem Addressed: The patent addresses the technical problem of "injectability failures," particularly needle clogging, when administering parenteral suspensions ('061 Patent, col. 3:56-61). This problem is especially acute for suspensions containing high concentrations or large sizes of microparticles, which are common in sustained-release drug formulations. The conventional approach was to keep the viscosity of the injection liquid low to facilitate flow ('061 Patent, col. 3:25-31).
  • The Patented Solution: The invention proposes a counter-intuitive solution: significantly increasing the viscosity of the liquid "fluid phase" of the suspension to at least 20 centipoise (cp) ('061 Patent, Abstract). This higher viscosity prevents the solid microparticles from separating from the liquid vehicle during the injection process, thereby reducing the likelihood of particle aggregation at the needle tip and subsequent clogging ('061 Patent, col. 4:56-62). The patent describes specific formulations and methods for preparing these high-viscosity, yet injectable, suspensions ('061 Patent, col. 4:1-14).
  • Technical Importance: This technology enables the reliable administration of high-concentration, large-particle, sustained-release drug formulations, which allows for less frequent dosing for patients and is a key feature of long-acting injectable treatments ('061 Patent, col. 3:41-55).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent Claim 1 and more broadly references infringement of "one or more claims" ('061 Patent, Compl. ¶¶ 51, 53).
  • Independent Claim 1 requires:
    • A composition suitable for injection through a needle into a host, comprising: microparticles comprising a polymeric binder; and an injection vehicle
    • The microparticles are suspended in the vehicle at a concentration greater than about 30 mg/ml
    • A fluid phase of the suspension has a viscosity greater than about 20 cp and less than about 600 cp at 20° C.
    • The viscosity of the fluid phase provides injectability through a needle of 18-22 gauge

III. The Accused Instrumentality

Product Identification

The accused instrumentality is "Defendants' Risperidone Product," an extended-release risperidone injection that is the subject of NDA No. 212849 (Compl. ¶¶18, 31).

Functionality and Market Context

  • The product is identified as a generic version of Plaintiffs' commercial product, Risperdal Consta®, an atypical antipsychotic drug used for treating schizophrenia and Bipolar I Disorder (Compl. ¶¶32, 34).
  • The complaint alleges on information and belief that the product, if approved, will be an injectable composition of risperidone that will compete directly with and displace sales of Risperdal Consta® (Compl. ¶¶36, 51). The complaint includes a diagram showing the chemical structure of risperidone, the active ingredient in both the patented and accused products (Compl. ¶26).
  • The complaint notes that Plaintiffs have not yet received the confidential materials of NDA No. 212849, and thus the specific technical details of the accused formulation are not yet known to them (Compl. ¶38).

IV. Analysis of Infringement Allegations

'061 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
[a] composition suitable for injection through a needle into a host, comprising: microparticles comprising a polymeric binder; and an injection vehicle... On information and belief, Defendants' Risperidone Product is alleged to be an injectable composition containing risperidone that meets the elements of Claim 1. ¶53 col. 3:62-65
wherein said microparticles are suspended in said injection vehicle at a concentration of greater than about 30 mg/ml to form a suspension... The complaint alleges that the accused product will be a suspension with a microparticle concentration meeting this limitation. ¶53 col. 18:9-10
wherein a fluid phase of said suspension has a viscosity greater than about 20 cp and less than about 600 cp at 20° C.... The complaint alleges that the fluid phase of the accused product's suspension will have a viscosity meeting this limitation. ¶53 col. 18:11-13
wherein the viscosity of said fluid phase of said suspension provides injectability of the composition through a needle ranging in diameter from 18-22 gauge. The complaint alleges that the viscosity of the accused product provides injectability through a standard-gauge needle as claimed. ¶53 col. 18:13-17
  • Identified Points of Contention:
    • Technical Questions: Because Plaintiffs have not yet reviewed Defendants' NDA, the infringement analysis is based on information and belief (Compl. ¶53). The central technical question will be whether discovery confirms that Defendants' product formulation actually possesses the specific physical properties recited in Claim 1. Key factual disputes will likely concern the precise concentration of the microparticle suspension and, critically, the measured viscosity of its "fluid phase."
    • Scope Questions: The interpretation of "fluid phase of said suspension" raises a potential claim construction question. Does this term refer to the injection vehicle prior to mixing with the microparticles, or to the liquid component of the final suspension after mixing, which could have different properties?

V. Key Claim Terms for Construction

  • The Term: "fluid phase of said suspension"

  • Context and Importance: This term is at the heart of the invention. The claim's viscosity limitation applies to this "fluid phase," so its definition is critical for determining infringement. Practitioners may focus on this term because the method of its measurement—whether from the pre-mixed vehicle or from the final suspension—could yield different results and be outcome-determinative.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification sometimes appears to use "injection vehicle" and "fluid phase" interchangeably, suggesting the term could be construed broadly to mean the liquid component itself. For example, the abstract states that the compositions include "an aqueous injection vehicle having a viscosity of at least 20 cp" ('061 Patent, Abstract).
    • Evidence for a Narrower Interpretation: The claim language itself recites the "fluid phase of said suspension," which could support a narrower interpretation requiring that the viscosity be measured from the final mixture after the microparticles have been suspended, not from the vehicle in its pre-mixed state ('061 Patent, col. 18:11).

  • The Term: "about"

  • Context and Importance: The claim uses "about" to qualify the key numerical limits for concentration ("about 30 mg/ml") and viscosity ("about 20 cp," "about 600 cp"). The scope of this term will be important, as the accused product's measured properties may be close to these recited boundaries.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patent provides numerous examples with a wide range of viscosities (e.g., 22.9 cp, 56.0 cp, 251 cp) that are all described as successful embodiments, which may support that "about" is intended to afford some flexibility around the stated values ('061 Patent, Tables 4 & 5; col. 8:43-51).
    • Evidence for a Narrower Interpretation: The specification states that "Viscosities of at least about 20 cp are necessary for successful and medically acceptable injectability rates," functionally linking the numerical value to a specific outcome ('061 Patent, col. 10:63-65). A party could argue this functional definition limits the downward range of "about 20 cp" to values that still achieve that successful result.

VI. Other Allegations

  • Indirect Infringement: The complaint includes allegations of induced and contributory infringement, asserting that Defendants will infringe through their manufacture, use, and sale of the product, and will induce and/or contribute to infringement by others (Compl. ¶52). This is likely predicated on the product's instructions for use, which would direct healthcare providers to prepare and administer the suspension in a manner that performs the claimed method.
  • Willful Infringement: The complaint alleges that Defendants had actual, pre-suit notice of the '061 patent (Compl. ¶54). The basis for this allegation is Defendants' own reference to the patent in their notice letter and, more significantly, their prior, unsuccessful IPR challenges to the patent's validity, which establishes knowledge of the patent and its claims (Compl. ¶¶54, 56).

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

  • A primary question will be one of factual proof: Will discovery show that the physical characteristics of Defendants' generic product—specifically its microparticle concentration and fluid phase viscosity—fall within the numerical ranges required by Claim 1 of the '061 patent? The case hinges on whether the accused product's formulation embodies the same technical solution as the patented invention.
  • A second issue will be one of definitional scope: How will the court construe the term "fluid phase of said suspension"? Whether this term is defined as the pre-mixed injection vehicle or the liquid component of the final, mixed suspension could be dispositive for the infringement analysis.
  • A key strategic question will be the impact of the prior IPR decision: How will the fact that the PTAB has already considered and rejected Defendants' invalidity arguments for the asserted claims influence the course of litigation, particularly with respect to the willfulness allegation and any potential settlement negotiations?