DCT

1:17-cv-00816

Amgen Inc v. Lupin Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:17-cv-00816, D. Del., 06/23/2017
  • Venue Allegations: Venue is alleged to be proper based on Defendant Lupin Pharmaceuticals, Inc. being a Delaware corporation and Defendant Lupin Ltd. having previously been sued in the district without objecting to personal jurisdiction and otherwise having sufficient contacts with the United States.
  • Core Dispute: Plaintiff alleges that Defendants’ submission of an Abbreviated New Drug Application (ANDA) to the U.S. Food and Drug Administration for a generic version of Plaintiff's SENSIPAR® tablets constitutes an act of infringement of a patent directed to a rapid-dissolution pharmaceutical formulation.
  • Technical Context: The technology concerns pharmaceutical formulations designed to improve the dissolution rate and bioavailability of cinacalcet hydrochloride, a drug used to treat disorders related to the parathyroid glands.
  • Key Procedural History: This lawsuit was triggered under the Hatch-Waxman Act by Defendants’ filing of ANDA No. 210548 with a Paragraph IV certification, asserting that the patent-in-suit is invalid or will not be infringed by the proposed generic product. The complaint was filed within the 45-day statutory window following receipt of the certification notice.

Case Timeline

Date Event
2003-09-12 ’405 Patent Priority Date
2004-03-08 FDA approves Amgen's SENSIPAR® for certain conditions
2011-02-25 FDA approves SENSIPAR® for an additional indication
2016-06-28 ’405 Patent Issued
2017-06-09 Date of Lupin's letter notifying Amgen of ANDA filing
2017-06-12 Amgen receives Lupin's notification letter
2017-06-23 Complaint Filed

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

U.S. Patent No. 9,375,405 - Rapid Dissolution Formulation of a Calcium Receptor-Active Compound

The Invention Explained

  • Problem Addressed: The patent describes that certain calcium receptor-active compounds, such as cinacalcet hydrochloride, are "insoluble or sparingly soluble in water," which can limit formulation options and result in "low bioavailability" of the drug when administered to a patient (’405 Patent, col. 1:8-20).
  • The Patented Solution: The invention claims a specific pharmaceutical composition for cinacalcet HCl that achieves a "defined dissolution profile" (’405 Patent, col. 1:29-32). This is accomplished by combining the active ingredient with a particular set of excipients (diluents, binders, and disintegrants) within specific weight-percentage ranges, which together are designed to maximize the dissolution of the compound from the dosage form (’405 Patent, Abstract; col. 1:21-25). The patent also describes manufacturing processes, such as granulation, to achieve the desired properties (’405 Patent, Fig. 1).
  • Technical Importance: By improving the dissolution rate, the formulation aims to enhance the in vivo bioavailability of a sparingly soluble but therapeutically important compound (’405 Patent, col. 1:21-25).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶37).
  • Essential elements of independent claim 1 include:
    • A pharmaceutical composition comprising (a) from about 10% to about 40% by weight of cinacalcet HCl in an amount from about 20 mg to about 100 mg;
    • and (b) from about 45% to about 85% by weight of a diluent selected from a specified group (e.g., microcrystalline cellulose, starch);
    • and (c) from about 1% to about 5% by weight of a binder selected from a specified group (e.g., povidone);
    • and (d) from about 1% to 10% by weight of a disintegrant selected from a specified group (e.g., crospovidone);
    • wherein the composition is for the treatment of hyperparathyroidism or related conditions. (’405 Patent, col. 13:17-39).
  • The complaint does not explicitly reserve the right to assert dependent claims, but this remains a possibility as the case proceeds.

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are Defendants' proposed generic cinacalcet hydrochloride tablets in 30 mg, 60 mg, and 90 mg dosage strengths, as described in ANDA No. 210548 (Compl. ¶¶7, 32).

Functionality and Market Context

The complaint alleges that Defendants seek FDA approval to "commercially manufacture, use, sell, and/or import a generic version of Amgen’s SENSIPAR®" (Compl. ¶26). SENSIPAR® is a "first-in-class molecule" used to treat secondary hyperparathyroidism in patients with chronic kidney disease, as well as hypercalcemia in patients with parathyroid carcinoma (Compl. ¶¶20, 23). The accused products are intended to be therapeutic equivalents to SENSIPAR® (Compl. ¶7). The complaint does not provide specific details on the formulation of the accused generic product beyond alleging its active ingredient is cinacalcet hydrochloride (Compl. ¶34).

IV. Analysis of Infringement Allegations

The complaint does not contain a claim chart or provide a detailed, element-by-element infringement analysis. It makes a general allegation that Defendants' submission of ANDA No. 210548 constitutes an act of infringement under 35 U.S.C. § 271(e)(2)(A), and that the product described therein would infringe "at least claim 1 of the ’405 patent" if commercially manufactured, used, or sold (Compl. ¶¶36-37). No probative visual evidence provided in complaint.

  • Identified Points of Contention:
    • Scope Questions: The primary dispute will likely center on whether the formulation detailed in Defendants' confidential ANDA falls within the specific weight-percentage ranges recited in claim 1 of the ’405 Patent. A central question is whether Defendants have "designed around" the patent by, for example, using excipients outside the claimed groups or formulating with weight percentages that fall outside the claimed ranges.
    • Technical Questions: A key evidentiary question for the court will be a direct comparison of the composition claimed in the patent with the composition of the proposed generic product. The details of Lupin's formulation, including the identity and quantity of all excipients, will be a focal point of discovery. Lupin's Paragraph IV certification letter alleges non-infringement and/or invalidity, suggesting it has a factual or legal basis for asserting its product is different from the patented invention or that the patent is not valid (Compl. ¶27).

V. Key Claim Terms for Construction

  • The Term: "from about X% to about Y% by weight"
  • Context and Importance: This term appears in elements (a), (b), (c), and (d) of claim 1 and defines the required amount of each key ingredient. The infringement analysis will depend entirely on whether the quantities of ingredients in Defendants' product fall within these ranges. Practitioners may focus on this term because even a small deviation from the recited numerical endpoints could be the basis for a non-infringement argument.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent consistently uses the word "about" when describing the ranges of components, suggesting the patentee did not intend for the numerical values to be strict, absolute limits (’405 Patent, col. 7:15-28). Plaintiff may argue this term should be interpreted to encompass a reasonable degree of variation.
    • Evidence for a Narrower Interpretation: Defendants may argue that the scope of "about" should be constrained by the specific examples and data provided in the patent. For instance, the specific formulations in Table 2 provide precise percentages for each component, which could be used to argue against an overly broad interpretation of the claimed ranges (’405 Patent, col. 12, Table 2).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon FDA approval, Defendants' sale of the ANDA products will induce and/or contribute to the infringement of claim 1 (Compl. ¶42). The basis for inducement would likely be the product's labeling, which would instruct physicians and patients to use the tablets for the patented therapeutic indications, thereby "using" the claimed composition.
  • Willful Infringement: The complaint does not use the term "willful," but it alleges that Defendants were "aware of the '405 patent" at the time they provided their Paragraph IV certification notice (Compl. ¶28). The prayer for relief requests that the court "Declare this to be an exceptional case under 35 U.S.C. §§ 285," which could entitle Plaintiff to an award of attorney fees (Compl. p. 9, ¶D).

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

  • A central factual question will be one of compositional overlap: Does the specific formulation disclosed in Lupin's ANDA—including the identity of its excipients and their precise weight percentages—fall within the literal scope of the ranges recited in claim 1 of the ’405 patent?
  • A dispositive legal question will be one of claim construction: How should the court interpret the term "about" as used in the patent's claims? The answer will determine the degree of flexibility, if any, in the claimed numerical ranges and could decide the issue of literal infringement.
  • A critical defense issue, as foreshadowed by the Paragraph IV certification, will be patent validity: Can Lupin prove by clear and convincing evidence that the claims of the ’405 patent are invalid, for instance, by showing the claimed formulation would have been obvious to a person of ordinary skill in the art at the time of the invention?