DCT

2:02-cv-00213

Alza Corp v. Mylan Laboratories

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:02-cv-00213, W.D. Pa., 01/25/2002
  • Venue Allegations: Venue is alleged to be proper based on Mylan Laboratories, Inc.'s principal place of business being within the district, and on the basis that the other Mylan defendants are wholly owned and controlled by Mylan Laboratories.
  • Core Dispute: Plaintiffs allege that Defendants' submission of an Abbreviated New Drug Application (ANDA) to the FDA seeking approval to market a generic version of Plaintiffs' Duragesic® transdermal fentanyl patch constitutes an act of patent infringement.
  • Technical Context: The technology involves transdermal drug delivery systems, specifically patches designed to deliver the potent opioid analgesic fentanyl through the skin at a controlled rate for managing chronic pain.
  • Key Procedural History: The asserted patent, U.S. Patent No. 4,588,580, has undergone two ex parte reexaminations, resulting in the issuance of Reexamination Certificate B1 4,588,580, which amended the claims, and Reexamination Certificate B2 4,588,580, which confirmed the patentability of all claims. This litigation was triggered by Mylan's Paragraph IV certification in its ANDA, asserting that the '580 patent is invalid or will not be infringed by Mylan's proposed generic product.

Case Timeline

Date Event
1984-07-23 '580 Patent Priority Date (Application Filing)
1986-05-13 U.S. Patent No. 4,588,580 Issued
1989-01-03 '580 B1 Reexamination Certificate Issued (Amended Claims)
1999-02-16 '580 B2 Reexamination Certificate Issued (Confirmed Claims)
2001-12-04 Mylan submits its ANDA No. 76-258 to the FDA
2001-12-11 Alza receives Mylan's first ANDA certification letter
2002-01-25 Complaint Filed

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

  • Patent Identification: U.S. Patent No. 4,588,580 - Transdermal Administration of Fentanyl and Device Therefor, issued May 13, 1986. The complaint also asserts the subsequently issued B1 and B2 Reexamination Certificates.

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of safely administering fentanyl, a highly potent opioid with a narrow therapeutic index where overdose can cause fatal respiratory depression (’580 Patent, col. 1:48-54). Prior administration was typically by injection, and creating a transdermal patch presented conflicting design constraints: the need to deliver a consistent dose over an extended period (e.g., 24 hours), the need to overcome natural variations in skin permeability, and the need to minimize the amount of residual drug left in a used patch to reduce potential for abuse or accidental exposure (’580 Patent, col. 1:55 - col. 2:8).
  • The Patented Solution: The patent discloses a transdermal delivery device (a patch) that administers the base form of fentanyl through the skin at a substantially constant and controlled rate for an extended period. The solution involves specific device constructions and formulations, such as a rate-controlling membrane paired with a drug reservoir containing an aqueous-ethanolic gel (’580 Patent, Abstract; col. 6:40-68). This combination dynamically maintains the drug's thermodynamic activity, ensuring a steady delivery rate even as the drug and the ethanol (a permeation enhancer) are depleted from the reservoir (’580 Patent, col. 6:53-68). The patent illustrates this concept in a cross-sectional diagram of a reservoir-style patch (Compl., Ex. A, p. 9, Fig. 1).
  • Technical Importance: This technology enabled the long-term, non-invasive administration of a powerful analgesic, providing stable blood plasma levels for patients with chronic pain and improving convenience over repeated injections (’580 Patent, col. 2:9-14).

Key Claims at a Glance

The complaint alleges infringement of the ""580 patent family"" generally and does not single out specific claims for assertion (Compl. ¶¶ 26-28). The analysis below focuses on a representative independent device claim as amended during reexamination. Plaintiffs reserve the right to assert additional claims.

  • Independent Claim 22 (as amended by B1 Reexamination):
    • A medical device for inducing and maintaining analgesia in a human being by the transdermal administration to a human being of a material selected from the group consisting of fentanyl and its analgetically effective derivatives at an analgetically effective rate for an extended period of time of at least about 24 hours and sufficient to induce and maintain analgesia which comprises:
    • (a) reservoir means containing a skin permeable form of said material in an amount sufficient to deliver said material at said analgetically effective rate for said extended period of time; and
    • (b) means for maintaining said reservoir means in material transmitting relationship to the intact skin on said human being.
      (B1 ’580 Patent, col. 5:16-34).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are the "generic fentanyl transdermal patches" that are the subject of Mylan's Abbreviated New Drug Application (ANDA) No. 76-258 (Compl. ¶17).

Functionality and Market Context

  • The Mylan product is intended to be a generic version of the Plaintiffs' commercial product, the Duragesic® fentanyl transdermal system (Compl. ¶¶ 14, 17). The complaint alleges that Mylan has filed its ANDA seeking FDA approval to manufacture, use, and sell these generic patches in the United States before the expiration of the ’580 patent family (Compl. ¶17). The complaint does not provide specific technical details regarding the construction, formulation, or mechanism of operation of Mylan's proposed generic patch.

IV. Analysis of Infringement Allegations

The complaint is brought under 35 U.S.C. § 271(e)(2)(A), where the submission of an ANDA for a drug claimed in a patent is a statutory act of infringement. The core allegation is that the product described in Mylan's ANDA, if commercially manufactured and sold, would infringe the ’580 patent family (Compl. ¶¶ 26-28). The complaint does not contain a detailed claim chart or specific factual allegations mapping features of the Mylan product to the patent's claim limitations.

  • '580 Patent Infringement Allegations
Claim Element (from Independent Claim 22, as amended) Alleged Infringing Functionality Complaint Citation Patent Citation
A medical device for inducing and maintaining analgesia...by the transdermal administration...of a material selected from the group consisting of fentanyl and its analgetically effective derivatives at an analgetically effective rate for an extended period of time of at least about 24 hours... The generic fentanyl transdermal patch described in Mylan's ANDA No. 76-258 is alleged to be a device designed to deliver fentanyl transdermally to provide analgesia. ¶17, ¶26 B1 ’580 Patent, col. 5:16-25
(a) reservoir means containing a skin permeable form of said material in an amount sufficient to deliver said material at said analgetically effective rate for said extended period of time The generic patch described in the ANDA is alleged to contain a reservoir with fentanyl for delivery over an extended period. ¶17, ¶26 B1 ’580 Patent, col. 5:26-30
(b) means for maintaining said reservoir means in material transmitting relationship to the intact skin on said human being. The generic patch described in the ANDA is alleged to include means, such as an adhesive, for maintaining it on a user's skin for drug delivery. ¶17, ¶26 B1 ’580 Patent, col. 5:31-34
  • Identified Points of Contention:
    • Scope Questions: A central issue will be the interpretation of claim terms in light of the patent's specification and its extensive prosecution history, which includes two reexaminations and claim amendments. The scope of "reservoir means" may be disputed—whether it is limited to the pouch-type embodiment of Figure 1 or also covers monolithic matrix designs. Likewise, the scope of "analgetically effective rate" and the implicit requirement for a "substantially constant" rate will likely be contested.
    • Technical Questions: The ultimate infringement question will be factual: does the specific design of the patch described in Mylan's confidential ANDA meet every limitation of an asserted claim? This will require a technical comparison of Mylan's drug formulation, rate-control mechanism, and physical construction against the construed claim language. The complaint does not provide evidence to answer this question, which will be a focus of discovery.

V. Key Claim Terms for Construction

  • The Term: "reservoir means"

  • Context and Importance: This term is fundamental to the structure of the claimed device. Its construction will determine whether the claims are limited to specific patch architectures (e.g., a pouch with a separate membrane) or broadly cover other designs, such as a monolithic matrix where the drug is integrated into the adhesive layer. Practitioners may focus on this term because Mylan's non-infringement position could depend on its product employing a design argued to be outside the scope of this limitation.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification describes multiple embodiments, including a "polymeric drug reservoir" within a multilaminate structure (Fig. 2) and a "drug reservoir/contact adhesive layer" in a "simple monolith" (Fig. 3), suggesting "reservoir means" is not limited to the pouch of Figure 1 (’580 Patent, col. 6:14-16, col. 6:46-48).
    • Evidence for a Narrower Interpretation: The detailed description of the preferred embodiment in Figure 1 distinguishes between the "drug reservoir 6" and the "rate controlling membrane 3," which could support an argument that "reservoir means" requires a structure that is distinct from the primary rate-controlling element (’580 Patent, col. 5:1-8).

  • The Term: "analgetically effective rate"

  • Context and Importance: The rate of drug delivery is a critical performance parameter of the invention. The definition of this term, particularly whether it requires a "substantially constant" flux as emphasized in the specification, is key to determining infringement.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The claims themselves do not recite a specific numerical rate or require "constant" delivery, only an "effective" one. The specification provides a wide therapeutic window for the administration rate, from 10 to 300 µg/hr, which may support a more flexible definition (’580 Patent, col. 3:1-3).
    • Evidence for a Narrower Interpretation: The background and description repeatedly emphasize the object of delivering the drug at a "substantially constant rate" (’580 Patent, col. 1:10-11, col. 1:56-57). Figures and examples, such as Figure 4, illustrate a steady-state flux. This could be used to argue that a product with a significantly different or peaking release profile does not deliver at an "analgetically effective rate" as understood by the inventors.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Mylan Laboratories and Mylan Pharmaceuticals are liable for inducing and/or contributing to the infringement committed by Mylan Technologies. The basis is the allegation that they "caused or participated in, contributed to, aided, abetted, directed and induced the submission of the Mylan ANDA" (Compl. ¶¶ 27-28).
  • Willful Infringement: The complaint alleges that Mylan had "actual and constructive notice" of the ’580 patent family prior to filing its ANDA, and that its infringement "has been, and continues to be, willful" (Compl. ¶29). This allegation is based on alleged pre-suit knowledge of the patent.

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

  • A core issue will be one of claim scope following reexamination: How did the amendments and arguments made during two separate reexaminations shape the enforceable scope of key terms like "reservoir means"? The court's construction of this term will likely determine whether Mylan's specific patch design, if it is a monolithic or matrix-style system, can be found to infringe.
  • The key evidentiary question will be one of technical and functional correspondence: Does the specific product formulation and delivery mechanism detailed in Mylan's confidential ANDA, once revealed in discovery, perform in a way that meets every limitation of a valid and asserted claim? This will involve a direct comparison between the accused product's rate of delivery and physical structure and the requirements of the patent's claims as construed by the court.