DCT

2:25-cv-14694

Axsome Malta Ltd v. Alkem Laboratories Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-14694, D.N.J., 08/15/2025
  • Venue Allegations: Plaintiff alleges venue is proper because Defendant is a foreign company, conducts business in the District of New Jersey, is registered to do business in the state, and the district will be a destination for the accused generic product.
  • Core Dispute: Plaintiff alleges that Defendant’s Abbreviated New Drug Application (ANDA) seeking to market a generic version of Plaintiff's Sunosi® (solriamfetol) tablets infringes four U.S. patents covering methods of administering the drug to specific patient populations.
  • Technical Context: The dispute is in the pharmaceutical sector, involving solriamfetol, a dopamine and norepinephrine reuptake inhibitor approved for treating excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea.
  • Key Procedural History: This is a Hatch-Waxman action triggered by Defendant’s submission of ANDA No. 218722 and its associated Paragraph IV certifications asserting that Plaintiff’s patents are invalid or not infringed. The complaint notes Defendant sent five separate notice letters to Plaintiff between August 2023 and July 2025, corresponding to different groups of patents listed in the FDA's Orange Book for Sunosi®. The complaint also references prior, consolidated litigation between the same parties.

Case Timeline

Date Event
2020-03-19 Priority Date for ’016 and ’362 Patents
2022-12-30 Priority Date for ’609 and ’145 Patents
2023-08-11 Alkem's First Paragraph IV Notice Letter Sent
2024-03-29 Alkem's Second Paragraph IV Notice Letter Sent
2024-06-26 Alkem's Third Paragraph IV Notice Letter Sent
2024-10-01 U.S. Patent No. 12,102,609 Issues
2024-10-15 Alkem's Fourth Paragraph IV Notice Letter Sent
2025-01-14 U.S. Patent No. 12,194,016 Issues
2025-04-01 U.S. Patent No. 12,263,145 Issues
2025-06-03 U.S. Patent No. 12,318,362 Issues
2025-07-03 Alkem's Fifth Paragraph IV Notice Letter Sent
2025-08-15 Complaint Filed

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

U.S. Patent No. 12,102,609 - Methods of Administering Solriamfetol to Lactating Women

The Invention Explained

  • Problem Addressed: The patent describes the challenge of treating lactating mothers who require solriamfetol for conditions like excessive daytime sleepiness, as pharmacokinetic studies showed the drug is readily absorbed and could be passed to a breastfeeding infant through breast milk (’609 Patent, col. 1:20-36). The invention seeks to reduce the potential for adverse events in the infant from this exposure (’609 Patent, col. 1:37-43).
  • The Patented Solution: The patent proposes a method wherein the lactating subject takes a daily dose of solriamfetol and then waits for a specified period—at least five hours—before feeding the infant breast milk (’609 Patent, Abstract). This delay is designed to allow the concentration of solriamfetol in the breast milk to decrease significantly from its peak, thereby minimizing the dose transferred to the infant (’609 Patent, col. 2:19-27).
  • Technical Importance: The claimed method provides a specific, actionable protocol that may allow lactating mothers who depend on solriamfetol to continue treatment while mitigating risks to their infants, addressing a key clinical and safety concern for this patient population (’609 Patent, col. 7:26-31).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶32).
  • The essential elements of Claim 1 are:
    • A method for decreasing the potential for adverse events from solriamfetol in an infant fed breast milk obtained from a human subject treated with solriamfetol.
    • Orally administering solriamfetol to the subject at a once-daily dose of about 150 mg.
    • Feeding the infant breast milk from the subject at least about 5 hours after administration.
    • Wherein the cumulative amount of solriamfetol excreted in breast milk over 8 hours is about 0.26 mg or lower.

U.S. Patent No. 12,194,016 - Methods of Providing Solriamfetol Therapy to Subjects with Impaired Renal Function

The Invention Explained

  • Problem Addressed: Solriamfetol is primarily cleared from the body through renal (kidney) excretion (’016 Patent, col. 2:40-47). The patent background explains that patients with impaired renal function would therefore have higher-than-normal exposure to the drug if given standard doses, increasing the risk of dose-dependent adverse effects (’016 Patent, col. 2:47-57). The prior art allegedly lacked a safe and effective dosing protocol for this specific patient group.
  • The Patented Solution: The invention provides a specific, structured dose-escalation regimen for subjects with mild renal impairment, defined by an estimated glomerular filtration rate (eGFR). The method involves starting with a first daily dose (75 mg) for a fixed period (3 days) before increasing to a second, higher daily dose (150 mg) for at least another fixed period (’016 Patent, Abstract; col. 49:15-26). This titration schedule is designed to improve tolerance to the drug’s side effects.
  • Technical Importance: The claimed method provides a tailored dosing protocol that allows solriamfetol to be used in subjects with mild renal impairment, a population that might otherwise be precluded from treatment or be at higher risk for adverse events (’016 Patent, col. 3:1-14).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶41).
  • The essential elements of Claim 1 are:
    • A method of treating excessive daytime sleepiness in a human subject with an eGFR of about 60-89 mL/min/1.73 m² or about 90 mL/min/1.73 m² or greater.
    • Providing a first oral daily dose equivalent to 75 mg of the active pharmaceutical compound (APC) for 3 days.
    • Subsequently providing a second oral daily dose equivalent to 150 mg APC for at least 3 days.

U.S. Patent No. 12,263,145 - Methods of Administering Solriamfetol to Lactating Women

  • Technology Synopsis: The ’145 Patent is related to the ’609 Patent and addresses the same technical problem of reducing infant exposure to solriamfetol via breast milk (’145 Patent, col. 1:12-18). The claimed solution is also a method of delaying breastfeeding for at least about 5 hours after administration, but it specifies a starting daily dose of about 75 mg rather than 150 mg (’145 Patent, col. 29:8-10).
  • Asserted Claims: The complaint asserts at least independent claim 1 (Compl. ¶50).
  • Accused Features: The infringement allegation is based on Alkem’s filing of an ANDA for a generic version of Sunosi®, which is available in a 75 mg strength, and the expectation that Alkem's proposed label will instruct or encourage infringing uses (Compl. ¶¶11, 50, 52).

U.S. Patent No. 12,318,362 - Methods of Providing Solriamfetol Therapy to Subjects with Impaired Renal Function

  • Technology Synopsis: The ’362 Patent is related to the ’016 Patent and addresses the same technical problem of safely dosing solriamfetol in patients with impaired renal function (’362 Patent, col. 2:40-57). The claimed method provides a specific dosing regimen based on the subject's eGFR, but this patent is directed to methods for reducing toxicity in subjects with moderate or severe renal impairment, as opposed to the mild impairment covered in the ’016 Patent. It claims a dose-escalation method for moderate impairment and a lower, non-escalating maximum dose for severe impairment (’362 Patent, col. 49:12-35).
  • Asserted Claims: The complaint asserts at least independent claim 1 (Compl. ¶59).
  • Accused Features: The alleged infringement arises from the filing of the ANDA and the allegation that Alkem's proposed product label will instruct physicians and patients to use dosing regimens that fall within the scope of the asserted claims for patients with moderate to severe renal impairment (Compl. ¶¶59, 61).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Alkem's Proposed Product," which is a generic version of solriamfetol oral tablets for which Defendant Alkem submitted ANDA No. 218722 to the FDA (Compl. ¶1, ¶17).

Functionality and Market Context

  • The Proposed Product is a generic equivalent of Axsome's Sunosi® oral tablets, which are indicated to improve wakefulness in adult patients with excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea (Compl. ¶2, ¶11). As this is a Hatch-Waxman action filed under 35 U.S.C. § 271(e)(2), the act of infringement is the submission of the ANDA itself, seeking approval to market the generic drug before the patents-in-suit expire (Compl. ¶23). The core of the infringement allegation is that the proposed labeling for Alkem's product will instruct users to administer the drug in a manner that practices the methods claimed in the patents-in-suit (Compl. ¶¶35, 44, 53, 62). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not contain claim charts or detailed infringement contentions. The infringement theory is based on the allegation that Alkem’s ANDA filing seeks approval for a product whose label will inevitably instruct users to perform the patented methods.

’609 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method for decreasing the potential for adverse events from solriamfetol in an infant fed breast milk obtained from a human subject treated with solriamfetol comprising: Alkem's proposed product label will allegedly instruct or encourage the use of its solriamfetol tablets in a manner that decreases potential for adverse events in breastfeeding infants. ¶32, ¶35 col. 1:37-43
administering solriamfetol orally at a once-daily dose of about 150 mg to the subject; and Alkem’s proposed product will be available in a 150 mg dosage strength, and its label will allegedly instruct or encourage once-daily administration to lactating subjects. ¶11, ¶34 col. 2:53-55
feeding the infant breast milk from the subject at least about 5 hours after administering the solriamfetol to the subject, Alkem’s label will allegedly instruct or encourage lactating subjects to wait at least 5 hours post-administration before breastfeeding to reduce infant exposure. ¶34, ¶35 col. 2:59-65
wherein the cumulative amount of solriamfetol excreted in breast milk over 8 hours is about 0.26 mg or lower. The complaint does not provide sufficient detail for analysis of this element. ¶32, ¶34 col. 29:13-14

’016 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 human subject in need thereof, comprising: Alkem's proposed product label will allegedly instruct or encourage the use of its solriamfetol tablets for treating excessive daytime sleepiness. ¶11, ¶43 col. 2:1-5
selecting a subject and determining the estimated glomerular filtration rate (eGFR) of the subject; and Alkem's label will allegedly instruct healthcare providers to assess a patient's renal function (eGFR) before prescribing or dosing the product. ¶43, ¶44 col. 3:45-51
providing to the subject having... an eGFR of about 60 mL/min/1.73 m² to about 89 mL/min/1.73 m²... a first oral daily dose equivalent to 75 mg... for 3 days; and Alkem's label will allegedly instruct a specific starting dose of 75 mg for patients with mild renal impairment for a duration of 3 days. ¶11, ¶43 col. 50:1-12
subsequently providing to the subject a second oral daily dose equivalent to 150 mg APC for at least 3 days. Alkem's label will allegedly instruct an escalation to a 150 mg dose after the initial 3-day period for patients with mild renal impairment. ¶11, ¶43 col. 50:1-12

Identified Points of Contention

  • Scope Questions: The infringement analysis for all patents will raise the question of whether the instructions on the Sunosi® label (and thus Alkem’s proposed label) mandate the specific steps of the claims, or if they allow for physician discretion that could result in non-infringing use. For the ’609 Patent, a key question will be whether the limitation "wherein the cumulative amount of solriamfetol excreted... is about 0.26 mg or lower" is a functional result that must be proven or a condition inherent in the preceding steps.
  • Technical Questions: A primary evidentiary question will be what Alkem's proposed product label actually states. As the case proceeds, discovery will focus on whether following the label’s instructions for the relevant patient populations (lactating mothers, renally impaired patients) would directly infringe or necessarily lead a significant number of users to infringe the asserted claims.

V. Key Claim Terms for Construction

  • The Term: "at least about 5 hours after administering" (’609 Patent, Claim 1)
  • Context and Importance: This temporal limitation is the central inventive concept for protecting the infant. Practitioners may focus on this term because its construction will determine whether a range of clinical practices falls within the claim scope. Alkem may argue for a strict interpretation tied to specific pharmacokinetic data, while Axsome may argue for a broader interpretation covering any clinically reasonable delay consistent with the patent's goal.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discusses a range of times, stating "at least about 2 hours (e.g., at least about 3, 4, or 5 hours)" (’609 Patent, col. 2:8-10), which may support the view that "about 5 hours" is not rigidly fixed.
    • Evidence for a Narrower Interpretation: The patent links specific waiting periods to specific reductions in infant exposure (’609 Patent, col. 8:3-11). An argument could be made that "about 5 hours" should be construed in light of the time required to achieve the functional result claimed, such as the cumulative excretion limit.
  • The Term: "providing... a first oral daily dose... for 3 days; and subsequently providing... a second oral daily dose" (’016 Patent, Claim 1)
  • Context and Importance: The infringement case hinges on whether Alkem's label will instruct this specific, sequential, multi-day titration schedule. The precise temporal requirements ("for 3 days," "subsequently") are critical. If the label provides this schedule merely as an example or allows physician discretion, it could evade a finding of induced infringement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term "providing" could be argued to be broad, encompassing not just a rigid command but also making available or recommending a course of treatment.
    • Evidence for a Narrower Interpretation: The claim language recites a specific, sequential process. The specification describes this dose escalation scheme as an "optimized" regimen designed to increase tolerance to adverse effects, suggesting the specific timing and sequence are important to the invention (’016 Patent, col. 3:1-9).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement for all four patents-in-suit. The basis for inducement is the allegation that Alkem, with knowledge of the patents, will intentionally encourage infringement by providing a product with a label that instructs physicians and patients to perform the claimed methods of administration (Compl. ¶¶35, 44, 53, 62).
  • Willful Infringement: While the complaint does not use the word "willful," it alleges that each count presents an "exceptional case" warranting an award of attorneys' fees under 35 U.S.C. § 285 (Compl. ¶¶39, 48, 57, 66). This allegation is predicated on Alkem’s alleged knowledge of the patents-in-suit, evidenced by its sending of multiple Paragraph IV notice letters prior to the lawsuit (Compl. ¶¶26-30).

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

  • A core issue will be one of induced infringement: Can Axsome prove that the language of Alkem’s proposed generic label will actively instruct and encourage a substantial number of physicians and patients to perform the exact, multi-step methods recited in the claims, or does the label allow sufficient physician discretion for substantial non-infringing uses?
  • A key legal question will be one of claim construction: Will the court construe the precise numerical and temporal limitations in the claims (e.g., "for 3 days," "at least about 5 hours," "about 0.26 mg or lower") narrowly, as strict requirements, or more broadly, as general guidelines? The outcome of this construction will likely determine whether the conduct described on the product label falls within the scope of the patents.