DCT

2:24-cv-10620

Axsome Malta Ltd v. Hikma Pharma USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:24-cv-10620, D.N.J., 11/20/2024
  • Venue Allegations: Venue is based on Defendant allegedly maintaining a regular and established physical place of business in the District of New Jersey, conducting business in the district, and having consented to jurisdiction in prior actions.
  • Core Dispute: Plaintiff alleges that Defendant’s Abbreviated New Drug Application (ANDA) to market a generic version of Plaintiff's Sunosi® (solriamfetol) tablets infringes patents related to methods of safely administering the drug to lactating women.
  • Technical Context: The technology involves pharmacokinetic analysis to define a specific dosing and infant feeding schedule that minimizes a breastfed infant's exposure to solriamfetol, a drug used to treat excessive daytime sleepiness.
  • Key Procedural History: This Hatch-Waxman litigation was initiated in response to Defendant’s Paragraph IV certification notice letters, sent between October 16 and October 18, 2024, which alleged that the patents-in-suit were invalid and/or would not be infringed by its proposed generic product.

Case Timeline

Date Event
2022-12-30 Earliest Priority Date for ’126 and ’609 Patents
2023-08-01 Hikma's First Paragraph IV Notice Letter Sent (approx.)
2024-03-18 Hikma's Second Paragraph IV Notice Letter Sent (approx.)
2024-08-22 Hikma's Third Paragraph IV Notice Letter Sent (approx.)
2024-09-03 Hikma's Fourth Paragraph IV Notice Letter Sent (approx.)
2024-09-17 U.S. Patent No. 12,090,126 Issued
2024-10-01 U.S. Patent No. 12,102,609 Issued
2024-10-16 Hikma's Fifth Paragraph IV Notice Letter Sent ('126 Patent) (approx.)
2024-10-18 Hikma's Sixth Paragraph IV Notice Letter Sent ('609 Patent) (approx.)
2024-11-20 Complaint Filing Date

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

U.S. Patent No. 12,090,126, “Methods of Administering Solriamfetol to Lactating Women,” Issued Sep. 17, 2024

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of how to administer solriamfetol, a treatment for excessive daytime sleepiness, to a lactating mother while reducing the potential for adverse events in the breastfed infant due to drug exposure through breast milk (Compl., Ex. A, ’126 Patent, col. 1:36-43).
  • The Patented Solution: The invention provides a specific method of treatment that involves first identifying appropriate patients (lactating mothers with a high score on the Epworth Sleepiness Scale and who experience sleep attacks), then administering solriamfetol according to a defined titration schedule, and critically, instructing the mother to wait at least 3.5 hours after taking the drug before breastfeeding the infant. This waiting period is designed to avoid the time of peak drug concentration in breast milk (’126 Patent, Claim 1; col. 7:61-63).
  • Technical Importance: The method provides a data-driven clinical protocol that may allow lactating mothers to be treated for debilitating sleepiness while mitigating risks to their infants.

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶31).
  • The essential elements of independent claim 1 are:
    • A method of treating excessive daytime sleepiness in a lactating human mother who wishes to breastfeed.
    • Determining the mother's Epworth Sleepiness Scale (ESS) score and whether she experiences sleep attacks.
    • For a mother with an ESS score of 15 or greater who has sleep attacks, providing a starting dose of solriamfetol (37.5 mg for OSA-related sleepiness, 75 mg for narcolepsy-related sleepiness) and titrating up to 150 mg.
    • Feeding the infant breast milk at least about 3.5 hours after drug administration to avoid peak drug concentrations.
    • The method results in a specified low daily infant dose of solriamfetol.
  • The complaint does not specify any dependent claims but reserves the right to assert additional claims (Compl. ¶31).

U.S. Patent No. 12,102,609, “Methods of Administering Solriamfetol to Lactating Women,” Issued Oct. 1, 2024

The Invention Explained

  • Problem Addressed: The patent addresses the same problem as the ’126 Patent: enabling safe administration of solriamfetol to nursing mothers by minimizing infant exposure via breast milk (Compl., Ex. B, ’609 Patent, col. 1:17-21).
  • The Patented Solution: This patent claims a method focused on a specific dose and waiting period. It comprises administering a once-daily dose of about 150 mg of solriamfetol and then feeding the infant breast milk at least 5 hours later. The patent teaches that this timing results in a specific, low cumulative amount of the drug being transferred to the infant over an 8-hour period (’609 Patent, Claim 1). The 5-hour waiting period corresponds to the drug's approximate elimination half-life in the mother (’609 Patent, col. 2:56-58).
  • Technical Importance: Similar to the ’126 Patent, this invention provides a specific, pharmacokinetically-grounded protocol for managing infant risk during maternal treatment with solriamfetol.

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶40).
  • The essential elements of independent claim 1 are:
    • A method for decreasing the potential for adverse events in an infant fed breast milk from a human subject treated with solriamfetol.
    • Administering solriamfetol orally at a once-daily dose of about 150 mg.
    • Feeding the infant breast milk from the subject at least about 5 hours after administration.
    • The method results in a cumulative amount of solriamfetol excreted in breast milk over 8 hours of about 0.26 mg or lower.
  • The complaint does not specify any dependent claims but reserves the right to assert additional claims (Compl. ¶40).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is Defendant Hikma’s proposed generic solriamfetol oral tablet product, for which it seeks FDA approval under ANDA No. 218016 ("Hikma's Proposed Product") (Compl. ¶1, 15).

Functionality and Market Context

  • As a generic version of Axsome's Sunosi® product, Hikma's Proposed Product is a dopamine and norepinephrine reuptake inhibitor intended to improve wakefulness in adults with excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea (Compl. ¶2, 9).
  • The infringement allegations are based on the submission of the ANDA itself, which is a statutory act of infringement, and the anticipated inducement of infringement that would occur if the product were marketed with a label that encourages or instructs physicians and patients to practice the patented methods (Compl. ¶31, 34, 40, 43). The complaint does not provide specific excerpts from the proposed product label.

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not contain a claim chart or provide sufficient detail to construct one. The infringement theory is based on 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 complaint further alleges that upon approval, Hikma will induce and contribute to infringement under §§ 271(b) and (c) by marketing its generic product with a proposed label that will instruct or encourage medical professionals and patients to use the drug in a manner that directly infringes the asserted claims of the ’126 and ’609 patents (Compl. ¶34, 35, 43, 44). The specific contents of Hikma’s proposed label, which will be central to the indirect infringement analysis, are not detailed in the complaint.

  • Identified Points of Contention:
    • Scope Questions: A central dispute may be whether Hikma's proposed product label will contain instructions or recommendations that meet the specific limitations of the method claims. For the ’126 Patent, this raises the question of whether the label must instruct a physician to perform the diagnostic step of "determining the Epworth Sleepiness Scale (ESS) total score" to induce infringement of claim 1.
    • Technical Questions: A key factual question will be whether the administration of Hikma's generic product according to its proposed label will necessarily result in the outcomes recited in the claims, such as the infant receiving a daily dose below the claimed threshold (’126 Patent, Claim 1) or the cumulative amount excreted in breast milk falling below the specified level (’609 Patent, Claim 1).

V. Key Claim Terms for Construction

  • The Term: "feeding the infant breast milk... at least about 3.5 hours after administration" (’126 Patent, Claim 1).

    • Context and Importance: This term defines the central waiting period in the claimed method. Its construction is critical because it sets the boundary between infringing and non-infringing conduct. Practitioners may focus on whether "about" provides significant flexibility or is narrowly constrained by the patent's technical disclosure.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The use of the word "about" itself suggests the patentee did not intend a rigid 3.5-hour cutoff. The specification also uses broader phrasing in other sections, such as "at least about 2 hours (e.g., at least about 3, 4, or 5 hours)" (’126 Patent, col. 2:11-13), which could be cited to support a more flexible range.
      • Evidence for a Narrower Interpretation: The claim links this waiting period to the purpose of "avoiding exposing the infant to the maximum concentrations of solriamfetol." The specification states that the peak concentration (Tmax) in breast milk is approximately 1.1 hours and that "waiting at least 3.5 hours after solriamfetol administration ensures avoidance of the Tmax even for outlier subjects" (’126 Patent, col. 7:61-63). This language may be used to argue that "about 3.5 hours" is anchored to this specific technical rationale and cannot be expanded significantly.

  • The Term: "feeding the infant breast milk... at least about 5 hours after administering the solriamfetol" (’609 Patent, Claim 1).

    • Context and Importance: This term is the core active step of the method claimed in the ’609 patent. The scope of "about 5 hours" will be a central issue for determining infringement.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: As with the ’126 Patent, the use of "about" suggests some leeway. The specification's exemplary language referring to waits of "at least about 2 hours (e.g., at least about 3, 4, or 5 hours)" could support a range (’609 Patent, col. 2:11-13).
      • Evidence for a Narrower Interpretation: The specification explicitly links the 5-hour mark to the drug's "elimination half-life... in the post-partum or lactating mother" and states this timing reduces infant exposure by "at least about 50%" (’609 Patent, col. 2:35-41, 56-58). This close connection between the time and a specific pharmacokinetic event could be used to argue that "about 5 hours" has a narrow, technically defined meaning.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. Inducement is alleged based on the assertion that Hikma’s proposed product label will intentionally encourage direct infringement by end-users and prescribers (Compl. ¶34, 43). Contributory infringement is alleged on the basis that Hikma's product is designed for an infringing use and lacks a substantial non-infringing use (Compl. ¶35, 44).
  • Willful Infringement: The complaint does not include a formal count for willful infringement. However, it alleges that Hikma has knowledge of the patents-in-suit via its Paragraph IV certifications and that its actions are encouraging infringement with this knowledge (Compl. ¶34, 43). The complaint also asserts that the case is "exceptional" and seeks attorneys' fees under 35 U.S.C. § 285 (Compl. ¶38, 47).

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

  • A core issue will be one of induced infringement: To what extent must Hikma’s proposed product label mirror the specific diagnostic, dosing, and timing steps of the asserted method claims to support a finding that it actively encourages or instructs an infringing use, particularly for the multi-step method of '126 Patent claim 1?
  • A key defense may turn on substantial non-infringing use: Can the accused product be used for its indicated purpose in a way that does not practice the claimed methods (e.g., in men, non-lactating women, or lactating women who do not follow the specific timing instructions), and if so, how does that impact the allegations of contributory and induced infringement?
  • The outcome may also depend on a question of definitional scope: Will the terms "about 3.5 hours" and "about 5 hours" be construed narrowly based on the specific pharmacokinetic data disclosed in the patents, or will they be interpreted more broadly, potentially altering the infringement analysis?