DCT

1:23-cv-01148

Bayer Healthcare LLC v. Padagis Israel Pharma Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:23-cv-01148, D. Del., 10/13/2023
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendants Padagis US LLC and Padagis LLC are organized under the laws of Delaware, and Padagis Israel Pharmaceuticals Ltd. is subject to personal jurisdiction in the district.
  • Core Dispute: Plaintiffs allege that Defendants’ filing of an Abbreviated New Drug Application (ANDA) to market a generic azelastine hydrochloride nasal spray constitutes an act of patent infringement under the Hatch-Waxman Act.
  • Technical Context: The technology concerns pharmaceutical formulations of azelastine, an antihistamine, designed for intranasal delivery to treat conditions like allergic rhinitis.
  • Key Procedural History: The litigation was triggered by Defendants notifying Plaintiffs on August 31, 2023, of their ANDA submission to the FDA, which included a certification asserting that Plaintiffs' patents are invalid, unenforceable, or will not be infringed. This act of filing an ANDA with a Paragraph IV certification is the statutory basis for the infringement action.

Case Timeline

Date Event
2004-11-24 Earliest Priority Date for '073, '919, and '050 Patents
2011-12-06 U.S. Patent No. 8,071,073 Issued
2013-08-27 U.S. Patent No. 8,518,919 Issued
2018-03-20 U.S. Patent No. 9,919,050 Issued
2023-08-31 Defendants' ANDA Notice Letter Sent to Plaintiffs
2023-10-13 Complaint Filed

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

U.S. Patent No. 8,071,073 - “Compositions Comprising Azelastine and Methods of Use Thereof”

  • The Invention Explained:
    • Problem Addressed: The patent’s background section states that azelastine hydrochloride, despite its effectiveness as an antihistamine, "possesses a strong bitter taste" (’073 Patent, col. 2:5-6). When administered as a nasal spray, a portion of the medication can drip into the pharynx, creating an "unpleasant and undesired taste experience by the patient" (’073 Patent, col. 2:10-14).
    • The Patented Solution: The invention is a liquid pharmaceutical composition that combines azelastine hydrochloride with a taste-masking agent, sucralose, to "mask the taste of bitter medicaments" (’073 Patent, col. 2:29-32). The composition may also include a viscosity-increasing agent, such as hypromellose, to reduce post-nasal drip and further improve patient experience (’073 Patent, col. 3:24-42).
    • Technical Importance: This formulation approach aims to improve "patient acceptability, convenience, and compliance" with azelastine-based nasal spray treatments by mitigating the primary negative side effect of a bitter aftertaste (’073 Patent, Abstract).
  • Key Claims at a Glance:
    • The complaint asserts at least dependent claims 2 and 3, which depend from independent claim 1 (Compl. ¶36).
    • Independent Claim 1 of the ’073 Patent includes the following essential elements:
      • A liquid pharmaceutical composition for treating allergic rhinitis or non-allergic vasomotor rhinitis
      • comprising about 0.100% (w/v) azelastine hydrochloride
      • about 0.100% (w/v) of hypromellose
      • about 0.05% (w/v) disodium edetate
      • about 0.025% (w/v) benzalkonium chloride 50% solution, NF
      • about 0.150% (w/v) sucralose
      • about 6.4% (w/v) sorbitol 70%
      • about 0.068% (w/v) sodium citrate dihydrate
      • QS water
    • The complaint reserves the right to assert additional claims (Compl. ¶41).

U.S. Patent No. 8,518,919 - “Compositions Comprising Azelastine and Methods of Use Thereof”

  • The Invention Explained:
    • Problem Addressed: The ’919 Patent addresses the same technical problem as its parent '073 Patent: the "strong bitter taste" of azelastine hydrochloride and the resulting poor patient experience from post-nasal drip following intranasal administration (’919 Patent, col. 2:5-14).
    • The Patented Solution: The invention claims a method of treating rhinitis by administering a liquid pharmaceutical composition that includes azelastine hydrochloride, the taste-masking agent sucralose, and sorbitol. By claiming the method of use, the patent covers the act of treating a patient with a formulation designed to solve the taste problem (’919 Patent, col. 2:35-41, Abstract).
    • Technical Importance: The claimed method provides a therapeutic approach that directly addresses a known barrier to patient compliance—unpleasant taste—thereby enhancing the practical utility of azelastine nasal sprays (’919 Patent, Abstract).
  • Key Claims at a Glance:
    • The complaint asserts at least independent claim 1 (Compl. ¶59).
    • Independent Claim 1 of the ’919 Patent includes the following essential elements:
      • A method of treating allergic rhinitis or non-allergic vasomotor rhinitis in a patient
      • comprising administering to the patient a liquid pharmaceutical composition
      • which comprises about 0.1% to about 0.15% (w/v) azelastine hydrochloride
      • sucralose
      • and sorbitol
    • The complaint reserves the right to assert additional claims (Compl. ¶63).

U.S. Patent No. 9,919,050 - “Compositions Comprising Azelastine”

  • Technology Synopsis: The ’050 Patent, part of the same patent family, claims a liquid intranasal composition for treating rhinitis. The patent describes the problem of azelastine hydrochloride's intense bitter taste, which can be experienced by patients due to post-nasal drip ('050 Patent, col. 2:5-14). The patented solution is a formulation that includes the active ingredient along with sucralose as a taste-masking agent and sorbitol, intended to improve patient compliance by making the treatment more palatable ('050 Patent, Abstract).
  • Asserted Claims: The complaint asserts at least independent claim 1 (Compl. ¶81).
  • Accused Features: The complaint alleges that the formulation of Padagis's ANDA Product, a nasal spray containing azelastine hydrochloride, infringes claim 1 of the ’050 patent (Compl. ¶¶81-82).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentality is "Padagis's ANDA Product," which is an "azelastine hydrochloride nasal spray, 0.2055 mg/spray" (Compl. ¶1).
  • Functionality and Market Context: The product is a generic version of Plaintiffs' Astepro® Allergy over-the-counter nasal spray (Compl. ¶¶3, 25). It is a liquid pharmaceutical solution formulated for intranasal administration to treat conditions such as allergic rhinitis (Compl. ¶32, ¶36). The complaint alleges that Defendants submitted an ANDA to the FDA seeking approval to manufacture and sell this product in the U.S. market prior to the expiration of the patents-in-suit (Compl. ¶1).
  • No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges infringement based on Defendants' submission of ANDA No. 216801, which under 35 U.S.C. § 271(e)(2)(A) is a statutory act of infringement if the product, once approved, would infringe (Compl. ¶39). The allegations are made on "information and belief" that the ANDA product's formulation and proposed use meet the patent claim limitations (Compl. ¶¶36-37).

’073 Patent Infringement Allegations

Claim Element (from Independent Claim 1, as narrowed by Claim 2) Alleged Infringing Functionality Complaint Citation Patent Citation
A liquid pharmaceutical composition for treating allergic rhinitis or non-allergic vasomotor rhinitis... Padagis's ANDA Product is a nasal spray solution for treating rhinitis. ¶32 col. 2:1-4
...comprising about 0.15% (w/v) azelastine hydrochloride... The ANDA Product is described as containing 205.5 mcg/spray of azelastine hydrochloride, which corresponds to a 0.15% solution. ¶2; ¶36 col. 10:45-65
...about 0.100% (w/v) of hypromellose... The complaint alleges on information and belief that the ANDA Product contains this component at the claimed concentration. ¶36 col. 3:37-42
...about 0.150% (w/v) sucralose... The complaint alleges on information and belief that the ANDA Product contains sucralose to mask the bitter taste of azelastine. ¶36 col. 3:1-15
...about 6.4% (w/v) sorbitol 70%... The complaint alleges on information and belief that the ANDA Product contains this component at the claimed concentration. ¶36 col. 14:15-20
...and other specified excipients. The complaint alleges on information and belief that the ANDA Product meets all limitations of the asserted claims. ¶36 col. 10:45-65

’919 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of treating allergic rhinitis or non-allergic vasomotor rhinitis in a patient in need thereof... Defendants' proposed product labeling will allegedly direct patients and healthcare providers to use the ANDA product to treat rhinitis. ¶55; ¶59 col. 2:1-4
...comprising administering to the patient a liquid pharmaceutical composition... The proposed labeling allegedly instructs administering the ANDA product, which is a liquid nasal spray. ¶59; ¶63 col. 3:51-56
...which comprises about 0.1% to about 0.15% (w/v) azelastine hydrochloride... The ANDA Product contains azelastine hydrochloride at a concentration of approximately 0.15%. ¶2; ¶59 col. 12:15-20
...sucralose... The complaint alleges on information and belief that the ANDA Product's formulation includes sucralose. ¶59 col. 3:1-15
...and sorbitol. The complaint alleges on information and belief that the ANDA Product's formulation includes sorbitol. ¶59 col. 14:15-20
  • Identified Points of Contention:
    • Evidentiary Questions: The complaint's allegations regarding the specific excipients (sucralose, hypromellose, sorbitol, etc.) and their precise concentrations are made on "information and belief." A central question for the court will be whether the formulation detailed in the confidential ANDA actually contains every component recited in the asserted claims at the specified concentrations.
    • Scope Questions: The claims recite specific concentrations qualified by the term "about." A potential point of contention may be the scope of this term. For instance, does the accused product's concentration of azelastine hydrochloride, described as "0.2055 mg/spray," fall within the scope of "about 0.15% (w/v)" as required by claim 2 of the '073 Patent and claim 1 of the '919 Patent?

V. Key Claim Terms for Construction

  • The Term: "about"
  • Context and Importance: This term appears before every numerical concentration in the asserted composition claims (e.g., "about 0.15% (w/v) azelastine hydrochloride," "about 0.150% (w/v) sucralose"). The scope of "about" is critical because infringement will depend on whether the concentrations in the accused generic product, even if not identical, fall within the range permitted by this term. Practitioners may focus on this term because the case could turn on whether slight variations in the formulation are sufficient to avoid infringement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discloses various ranges for the components, which may suggest the inventors did not intend for the specific numerical values in the claims to be absolute. For example, the specification describes suitable sucralose concentrations from "about 0.001% to 1%" (’073 Patent, col. 3:10-11).
    • Evidence for a Narrower Interpretation: The claims themselves recite concentrations to two or three decimal places (e.g., "0.150%," "0.068%"), which may suggest that "about" is intended to cover only minor manufacturing tolerances or measurement variability, not significant formulation differences. The presence of dependent claims that modify the concentration of the active ingredient further suggests the precision of the recited values is significant.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement of infringement for all three patents-in-suit. The basis for this allegation is that Defendants' proposed product labeling will instruct medical professionals and patients to administer the ANDA product in a manner that directly infringes the asserted method claims (e.g., of the ’919 Patent) and leads to the direct infringement of the composition claims by the end-user (Compl. ¶43, ¶64, ¶91). The complaint also alleges contributory infringement of the ’919 patent, stating the ANDA product is not a staple article of commerce suitable for substantial noninfringing use (Compl. ¶65).
  • Willful Infringement: While the complaint does not use the term "willful," it alleges that Defendants have "knowledge of the claims of the ['073, '919, and '050 patents]" and have "continued to assert its intent to manufacture, offer for sale, sell, distribute, and/or import" the accused product (Compl. ¶44, ¶66, ¶92). These allegations of knowledge, established at least by the pre-suit notice letter, could form the basis for a later claim of willful infringement.

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

  • A central issue will be one of factual correspondence: Does the specific formulation of active and inactive ingredients disclosed in Defendants' confidential ANDA contain every component, at the claimed concentrations, recited in the asserted claims of the patents-in-suit? The litigation will likely depend on discovery of the ANDA's contents to resolve the complaint's "information and belief" allegations.
  • A key legal question will be one of definitional scope: How broadly will the term "about" be construed when applied to the precise percentage concentrations listed in the composition claims? The outcome of this claim construction issue may determine whether minor variations between the patented formulation and the accused generic product are sufficient to establish non-infringement.