DCT

1:21-cv-01808

Allergan Inc v. Aurobindo Pharma Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:21-cv-01808, D. Del., 12/23/2021
  • Venue Allegations: Venue is alleged based on Defendants' distribution and sale of generic drugs in Delaware, generating substantial revenue within the district, and having previously availed themselves of the court's jurisdiction by filing patent counterclaims in prior, unrelated litigation.
  • Core Dispute: Plaintiff alleges that Defendants’ submission of an Abbreviated New Drug Application (ANDA) to the FDA for a generic version of Plaintiff's ALPHAGAN® P 0.1% ophthalmic solution constitutes an act of patent infringement.
  • Technical Context: The technology concerns pharmaceutical formulations for ophthalmic solutions used to treat elevated intraocular pressure, a condition associated with glaucoma and ocular hypertension.
  • Key Procedural History: This is a Hatch-Waxman action triggered by Defendants' filing of ANDA No. 216666, which seeks FDA approval to market a generic drug prior to the expiration of Plaintiff's patent. The ANDA included a Paragraph IV certification asserting that the patent-in-suit is invalid, unenforceable, or will not be infringed. Plaintiff was notified via a letter dated November 11, 2021.

Case Timeline

Date Event
2000-07-14 ’961 Patent Priority Date
2005-08-19 Allergan's NDA No. 021770 Approved
2014-10-14 ’961 Patent Issue Date
2021-11-11 Allergan Receives Notice Letter of ANDA Filing
2021-12-23 Complaint Filing Date

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

U.S. Patent No. 8,858,961 - "Compositions Containing Alpha-2-Adrenergic Agonist Components"

  • Patent Identification: U.S. Patent No. 8,858,961, “Compositions Containing Alpha-2-Adrenergic Agonist Components,” issued October 14, 2014.

The Invention Explained

  • Problem Addressed: The patent addresses a conflict in formulating ophthalmic drugs containing alpha-2-adrenergic agonists like brimonidine. These compounds are most effective at penetrating eye tissue at a neutral or alkaline pH (above 7.0), where they are predominantly uncharged. However, at these same pH levels, they become significantly less soluble in aqueous solutions, creating a risk of the drug precipitating and reducing its bioavailability and therapeutic consistency (ʼ961 Patent, col. 2:40-65).
  • The Patented Solution: The invention claims to solve this problem by adding a specific "solubility enhancing component"—carboxymethylcellulose (CMC)—to the aqueous formulation. The patent asserts that CMC increases the solubility of brimonidine at a higher pH, allowing the formulation to be maintained at a therapeutically optimal pH (e.g., 7.0-8.0) without the active ingredient precipitating out of the solution ('961 Patent, col. 4:1-4, Fig. 1). This enables the creation of a stable, effective formulation that leverages the enhanced membrane permeability of the drug in its uncharged state ('961 Patent, col. 3:61-65).
  • Technical Importance: This formulation strategy allows for a product with a lower concentration of the active drug (e.g., 0.1% brimonidine) to achieve a therapeutic effect comparable to older, higher-concentration formulations (e.g., 0.2%), which may lead to a reduced incidence of side effects ('961 Patent, col. 21:1-9).

Key Claims at a Glance

  • The complaint alleges infringement of claims 1-9 (Compl. ¶31). Independent Claim 1 is asserted.
  • Independent Claim 1:
    • A therapeutically effective aqueous ophthalmic composition for lowering intraocular pressure comprising: a solution containing 0.1% (w/v) of a compound selected from the group consisting of brimonidine, a salt of brimonidine,
    • wherein the solution further comprises an oxy-chloro preservative and carboxymethylcellulose,
    • wherein the composition has a pH between 7.0-8.0.
  • The complaint does not explicitly reserve the right to assert other claims but puts claims 1-9 at issue.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is Defendants' generic "brimonidine tartrate ophthalmic solution, 0.1%," which is the subject of Abbreviated New Drug Application (ANDA) No. 216666 (Compl. ¶7).

Functionality and Market Context

  • The ANDA Product is a generic copy of Allergan's ALPHAGAN® P 0.1% and is intended for the same therapeutic use: "the reduction of elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension" (Compl. ¶7, ¶28). By filing the ANDA, Defendants seek FDA approval to manufacture and sell this product in the United States as a lower-cost, generic alternative to Allergan's branded drug before the expiration of the ’961 patent (Compl. ¶29).

IV. Analysis of Infringement Allegations

The complaint alleges that the act of filing ANDA No. 216666 constitutes infringement under 35 U.S.C. § 271(e)(2)(A), as the product described therein, if commercially marketed, would infringe the ’961 patent. The complaint notes that the Defendants' Notice Letter did not contest infringement, instead alleging invalidity (Compl. ¶31). The following chart summarizes the infringement theory for the lead independent claim, based on the allegation that the ANDA product is a generic copy of the patented formulation.

’961 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A therapeutically effective aqueous ophthalmic composition for lowering intraocular pressure comprising: a solution containing 0.1% (w/v) of a compound selected from the group consisting of brimonidine, a salt of brimonidine, The ANDA Product is identified as a "brimonidine tartrate ophthalmic solution, 0.1%," which is a salt of brimonidine at the claimed concentration. ¶7 col. 23:4-6
wherein the solution further comprises an oxy-chloro preservative and carboxymethylcellulose, As a generic copy of the product covered by the Orange Book-listed ’961 patent, the ANDA product is alleged to contain the same excipients required by the claims, including an oxy-chloro preservative and carboxymethylcellulose. ¶32 col. 23:7-8
wherein the composition has a pH between 7.0-8.0. The ANDA Product is alleged to infringe claims requiring a pH in this range, consistent with the formulation of the branded drug it seeks to copy. ¶32 col. 23:9

No probative visual evidence provided in complaint.

Identified Points of Contention

  • Evidentiary Question: The primary question for infringement is factual: does the formulation specified in Defendants' confidential ANDA submission contain each element of the asserted claims? The complaint proceeds on the basis that, as a generic copy, it does.
  • Scope Questions: Given that the Defendants' Notice Letter appears to focus on invalidity rather than non-infringement, the central dispute may not be over infringement. However, a potential point of contention could arise regarding the scope of "oxy-chloro preservative," and whether the specific preservative in the ANDA product falls within the construction of that term.

V. Key Claim Terms for Construction

  • The Term: "carboxymethylcellulose"

    • Context and Importance: This is the patent’s designated "solubility enhancing component" and is essential to the claimed solution. Its presence is a required element of independent claim 1. Practitioners may focus on this term because any ambiguity in its definition could create an avenue for a non-infringement argument, should the Defendants' formulation use a variant or derivative of CMC.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification introduces the concept of a general "solubility enhancing component (SEC)" and lists other potential candidates, suggesting the inventors contemplated a class of agents, even though the claims are narrowed to CMC ('961 Patent, col. 4:1-9).
      • Evidence for a Narrower Interpretation: The patent provides specific examples, concentrations, and performance data for carboxymethylcellulose (e.g., Example 2, Table III, Figure 1). A party could argue these specific disclosures limit the term to the types and grades of CMC that produce the results shown in the patent ('961 Patent, col. 19).

  • The Term: "oxy-chloro preservative"

    • Context and Importance: This is another required excipient in the claimed formulation. Its definition is critical because different "oxy-chloro" compounds exist, and the specific preservative used in the ANDA product must fall within the scope of this term for literal infringement.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification provides a list of "oxy-chloro components" that includes "hypochlorite components... chlorate components... perchlorate components; and chlorite components," suggesting the term is not limited to a single compound ('961 Patent, col. 14:52-57).
      • Evidence for a Narrower Interpretation: The patent's examples repeatedly identify a specific commercial product, "Purite™," as the preservative ('961 Patent, col. 14:1-2; Table V). Dependent claim 5 originally specified "Purite," which was later changed to "chlorine dioxide" via a Certificate of Correction. This may support an argument that the term should be narrowly construed to mean stabilized chlorine dioxide.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement under 35 U.S.C. § 271(b). The factual basis is the allegation that Defendants know and intend for physicians and patients to use the ANDA product according to its instructions and label, which will direct the administration of the infringing formulation to lower intraocular pressure (Compl. ¶34, ¶40).
  • Willful Infringement: The complaint does not use the term "willful," but it requests treble damages and a finding of an exceptional case (Compl. Prayer for Relief ¶f, ¶g). The basis for this appears to be Defendants' knowledge of the ’961 patent, as evidenced by their filing of a Paragraph IV certification against it as part of their ANDA submission (Compl. ¶33).

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

The complaint, and the nature of ANDA litigation, suggest that the core of this dispute will not be over whether the generic product infringes, but whether the patent is valid. The key questions for the case are therefore likely to be:

  1. A central issue will be one of validity: Was the claimed combination of 0.1% brimonidine tartrate, carboxymethylcellulose, an oxy-chloro preservative, and a pH between 7.0-8.0 obvious to a person of ordinary skill in the art at the time of the invention, in light of prior art concerning ophthalmic formulations?

  2. A secondary issue may be one of definitional scope: Assuming the ANDA product's formulation is not an exact copy, can the term "oxy-chloro preservative" be construed to read on the specific chemical used in the accused product, or is its scope limited by the specification's examples and prosecution history to stabilized chlorine dioxide?