DCT

2:24-cv-10618

Axsome Malta Ltd v. Hetero USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:24-cv-10618, D.N.J., 11/20/2024
  • Venue Allegations: Plaintiff alleges venue is proper in the District of New Jersey based on Defendant Hetero USA Inc.’s established physical place of business in Piscataway, NJ, and because the district will be a destination for the accused generic product. The complaint also asserts that the Hetero entities have previously consented to personal jurisdiction in the district in other ANDA-related cases.
  • Core Dispute: Plaintiff alleges that Defendant’s filing of an Abbreviated New Drug Application (ANDA) to market a generic version of Plaintiff's Sunosi® (solriamfetol) tablets constitutes an act of infringement of a patent covering methods of administering the drug to lactating women.
  • Technical Context: The technology relates to pharmaceutical methods designed to ensure the safety of breastfed infants whose mothers are being treated with solriamfetol, a drug for excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea.
  • Key Procedural History: This action was initiated under the Hatch-Waxman Act following Defendant’s submission of ANDA No. 218654 and a subsequent Paragraph IV certification notice letter, sent no earlier than October 10, 2024, alleging the patent-in-suit is invalid, unenforceable, or will not be infringed by the proposed generic product.

Case Timeline

Date Event
2022-12-30 U.S. Patent No. 12,090,126 Priority Date
2023-08-15 Hetero sends first Paragraph IV Notice Letter (earliest date)
2023-12-01 Hetero sends second Paragraph IV Notice Letter (earliest date)
2024-03-11 Hetero sends third Paragraph IV Notice Letter (earliest date)
2024-09-17 U.S. Patent No. 12,090,126 Issues
2024-09-23 Hetero sends fourth Paragraph IV Notice Letter (earliest date)
2024-10-10 Hetero sends fifth Paragraph IV Notice Letter for '126 patent (earliest date)
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"

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of how to treat a lactating mother with solriamfetol, a drug known to be excreted in breast milk, while minimizing the risk of adverse events to the breastfed infant (’126 Patent, col. 1:36-41).
  • The Patented Solution: The invention is a method that involves a specific dosing and administration schedule. A lactating mother is administered a defined daily dose of solriamfetol, and she must then wait for a specified period of time—for example, at least 3.5 hours—before breastfeeding her infant. This delay is designed to allow the concentration of the drug in the breast milk to fall below its peak level, thereby reducing the infant's exposure (’126 Patent, Abstract; col. 2:50-63).
  • Technical Importance: This method provides a protocol that allows women suffering from conditions like narcolepsy to continue necessary treatment while also breastfeeding, addressing a significant safety concern for a specific patient population (’126 Patent, col. 14:45-49).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and reserves the right to assert other claims (Compl. ¶36).
  • The essential elements of independent claim 1 include:
    • A method for treating excessive daytime sleepiness (EDS) in a lactating human mother who wishes to breastfeed.
    • First, determining the mother's Epworth Sleepiness Scale (ESS) score and whether she experiences sleep attacks.
    • Second, if the mother has an ESS score of 15 or greater and experiences sleep attacks, providing a specific starting dose of solriamfetol (37.5 mg for OSA-related EDS or 75 mg for narcolepsy-related EDS), with potential dose escalations.
    • Third, feeding the infant breast milk obtained at least about 3.5 hours after the mother takes the drug to avoid peak concentrations.
    • The claim further recites specific pharmacokinetic parameters, including the median Tmax (time to peak concentration) in breast milk and the resulting daily infant dose at various maternal dosage levels (’126 Patent, col. 29:41-30:17).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Hetero's Proposed Product," a generic version of Sunosi® (solriamfetol) oral tablets, for which Defendant filed ANDA No. 218654 (Compl. ¶¶1, 16, 27).

Functionality and Market Context

  • The complaint alleges that Hetero seeks FDA approval to manufacture and sell its generic solriamfetol tablets for the same indications as the brand-name drug Sunosi®, namely to improve wakefulness in adults with excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea (Compl. ¶¶2, 10). The infringement theory is based on the future sale and use of this product upon FDA approval (Compl. ¶28).
  • No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not contain a detailed claim chart. The infringement theory, typical for ANDA litigation, is that the instructions for use on the proposed generic product's label will induce physicians and patients to perform the patented method.

'126 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of treating excessive daytime sleepiness in a lactating human mother... The proposed generic product's label will allegedly instruct its use for treating excessive daytime sleepiness, and will be prescribed to patients including lactating mothers. ¶38, ¶39 col. 14:50-54
a) determining the Epworth Sleepiness Scale (ESS) total score of the mother and if the mother experiences sleep attacks while caring for the infant, The proposed label will allegedly instruct physicians to diagnose excessive daytime sleepiness in a manner that satisfies this specific two-part assessment before prescribing the drug. ¶38, ¶39 col. 14:55-58
b) providing the mother having an ESS total score of 15 or greater and who experiences sleep attacks... a starting dose of solriamfetol of 37.5 mg once daily if the excessive daytime sleepiness is associated with obstructive sleep apnea, or 75 mg once daily if... associated with narcolepsy, and doubling the dose at intervals of at least 3 days up to 150 mg once daily; and The proposed label will allegedly instruct the specific starting dosages and titration schedule for the indicated conditions as recited in the claim. ¶38, ¶39 col. 14:58-65
c) feeding the infant breast milk obtained from the lactating mother at least about 3.5 hours after administration of the solriamfetol... The proposed label will allegedly include instructions or warnings advising a waiting period before breastfeeding that corresponds to the claimed timing, in order to mitigate risk to the infant. ¶38, ¶39 col. 15:1-5

Identified Points of Contention

  • Scope Questions: A primary question for the court will be whether the language of Hetero's proposed drug label, once produced in discovery, will "encourage, recommend, or promote" the performance of every step of the claimed method. For instance, does the label require the specific "Epworth Sleepiness Scale" test, or does it allow for a more general diagnosis of excessive daytime sleepiness that might fall outside the claim's scope?
  • Technical Questions: The case will turn on the specific instructions and warnings contained in the proposed labeling. A key evidentiary question will be whether following the label's directions for use would inevitably lead a physician and a lactating patient to practice the patented method, thereby making Hetero liable for inducing infringement.

V. Key Claim Terms for Construction

"determining the Epworth Sleepiness Scale (ESS) total score of the mother and if the mother experiences sleep attacks while caring for the infant"

  • Context and Importance: This term defines the specific diagnostic prerequisites for initiating treatment under the claimed method. Practitioners may focus on this term because the infringement analysis will depend on whether a generic label must explicitly require this two-part diagnostic evaluation, or if instructions for a more general diagnosis of the underlying condition are sufficient.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent’s background discusses "excessive daytime sleepiness" more broadly as a condition, which a party could argue suggests the specific diagnostic method is illustrative, not exclusively required (’126 Patent, col. 9:4-16).
    • Evidence for a Narrower Interpretation: The claim language itself is highly specific. The specification repeatedly ties the treatment method to these exact criteria, stating that the method involves "providing the mother with an ESS total score of 15 or greater and who experiences sleep attacks" with a specific starting dose, suggesting these are not optional observations but mandatory conditions (’126 Patent, col. 14:55-62).

"at least about 3.5 hours"

  • Context and Importance: This term is the core of the safety protocol claimed by the patent. Its construction, particularly the scope of "about," will be critical for determining infringement. A defendant may argue that a label recommending a different waiting period (e.g., "4 hours" or "a few hours") does not meet this limitation.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides examples of different waiting periods, such as "at least about 2 hours (e.g., at least about 3, 4, or 5 hours)," which may support a more flexible reading of "about 3.5 hours" to encompass a range of times that achieve the same goal of avoiding peak drug concentration (’126 Patent, col. 2:57-59).
    • Evidence for a Narrower Interpretation: The claim recites a specific value, "3.5 hours." The patent's clinical data explains that the median Tmax (time to peak concentration) in breast milk is 1.1 hours and the range is 1 to 3 hours, which suggests that "3.5 hours" was chosen as a specific, evidence-based safety margin, not an arbitrary time (’126 Patent, col. 8:56-62).

VI. Other Allegations

Indirect Infringement

  • The complaint alleges both induced and contributory infringement. The inducement claim is based on the allegation that Hetero's product label will intentionally encourage physicians and patients to perform the patented method (Compl. ¶39). The contributory infringement claim alleges that Hetero's product is specifically designed for an infringing use and lacks a substantial non-infringing use (Compl. ¶40).

Willful Infringement

  • The complaint does not use the word "willful" but does allege that Hetero had knowledge of the '126 patent via its Paragraph IV notice letter sent no earlier than October 10, 2024 (Compl. ¶34). It further alleges the case is "exceptional" and seeks attorneys' fees under 35 U.S.C. § 285, which is often predicated on conduct akin to willfulness (Compl. ¶43).

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

  • A core issue will be one of induced infringement by labeling: Does the specific text of Hetero’s proposed generic drug label—which is central to the case but not included in the complaint—instruct or encourage physicians and patients to perform every single step of the patented method, from the specific diagnostic criteria to the precise administration and feeding schedule?
  • A key legal question will be one of claim scope and necessity: Is the recitation of the "Epworth Sleepiness Scale" and "sleep attacks" in Claim 1 a strict requirement for infringement, or can it be satisfied by a physician's more general diagnosis of excessive daytime sleepiness based on a label with broader language? The outcome may turn on whether the claimed diagnostic steps are interpreted as essential or merely illustrative.