DCT

2:24-cv-07511

Axsome Malta LTD. v. Aurobindo Pharma USA, INC.

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:24-cv-07511, D.N.J., 07/02/2024
  • Venue Allegations: Venue is based on Defendant Aurobindo Pharma USA, Inc. maintaining a regular and established physical place of business within the District of New Jersey.
  • Core Dispute: Plaintiff alleges that Defendant's submission of an Abbreviated New Drug Application (ANDA) for a generic version of solriamfetol tablets constitutes an act of infringement of a patent covering specific methods for dosing the drug in patients with renal impairment.
  • Technical Context: The technology involves pharmacokinetic-based dosing regimens for solriamfetol, a drug used to treat excessive daytime sleepiness, specifically tailored for patients with varying degrees of impaired kidney function to mitigate adverse effects.
  • Key Procedural History: The action was precipitated by Defendant’s submission of an ANDA and its associated Paragraph IV certification, sent to Plaintiff on or after May 21, 2024, asserting that the patent-in-suit is invalid and/or not infringed by its proposed generic product.

Case Timeline

Date Event
2020-03-19 ’404 Patent Priority Date
2024-04-30 ’404 Patent Issue Date
2024-05-21 Defendant sent Paragraph IV Certification for the ’404 Patent (on or after this date)
2024-07-02 Complaint Filing Date

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

U.S. Patent No. 11,969,404 - "Methods of Providing Solriamfetol Therapy to Subjects with Impaired Renal Function"

  • Patent Identification: U.S. Patent No. 11,969,404, "Methods of Providing Solriamfetol Therapy to Subjects with Impaired Renal Function", issued April 30, 2024.

The Invention Explained

  • Problem Addressed: The patent’s background section explains that solriamfetol (also referred to as APC-HCl) is primarily eliminated from the body through renal excretion. This poses a risk for patients with impaired kidney function, as they would be expected to have higher drug exposure, potentially exacerbating dose-dependent adverse effects such as headache, nausea, and anxiety. Before the invention, it was not known what dose, if any, would be safe for this patient population. (’404 Patent, col. 2:31-54).
  • The Patented Solution: The invention provides specific methods for administering solriamfetol to patients with moderate or severe renal impairment. The solution involves tailoring the dose and escalation schedule based on the patient's estimated glomerular filtration rate (eGFR). For moderately impaired patients, the method specifies starting with a low dose (37.5 mg) for at least five days before escalating to a reduced maximum dose (75 mg). For severely impaired patients, it teaches a single, low maximum daily dose (37.5 mg). This tailored approach is designed to minimize adverse effects while providing therapeutic benefit. (’404 Patent, col. 3:1-17).
  • Technical Importance: The claimed dosing regimens provide a way to safely administer a therapeutic agent to a specific and vulnerable patient population for whom the drug might otherwise be unsuitable due to safety concerns. (’404 Patent, col. 2:56-62).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1.
  • The essential elements of independent claim 1 are:
    • A method of treating a human subject with [R]-2-amino-3-phenylpropylcarbamate (APC).
    • The method comprises determining if the patient has moderate or severe renal impairment based on their estimated glomerular filtration rate (eGFR).
    • For a patient with moderate renal impairment (eGFR of about 30-59 mL/min/1.73 m²), the method requires:
      • Providing a first daily dose of 37.5 mg APC for at least five days (day one to day n₁, where n₁ ≥ 5).
      • Providing a second daily dose of 75 mg APC starting after the initial period (on day n₂+1).
      • The daily dose must not exceed 75 mg APC.
    • For a patient with severe renal impairment (eGFR of about 15-29 mL/min/1.73 m²), the method requires:
      • Providing a daily dose of 37.5 mg APC.
      • The daily dose must not exceed 37.5 mg APC.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Aurobindo's Proposed Product," a generic version of solriamfetol oral tablets for which Defendant submitted ANDA No. 218725 to the FDA for approval. (Compl. ¶1, ¶15).

Functionality and Market Context

  • The proposed product is a generic equivalent of Plaintiff's Sunosi® brand tablets. Sunosi® is a dopamine and norepinephrine reuptake inhibitor indicated to improve wakefulness in adults with excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea. (Compl. ¶9). The complaint alleges that upon approval, Defendant will manufacture, market, and sell this generic product in the United States. (Compl. ¶15, ¶25). The infringement allegation is based on the statutory act of filing the ANDA, which seeks approval to market the drug for the same indications as the brand-name product. (Compl. ¶33).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

The complaint alleges that the submission of the ANDA itself constitutes an act of infringement under 35 U.S.C. § 271(e)(2)(A), and that commercialization post-approval would constitute direct, induced, and contributory infringement. (Compl. ¶¶33, 35-37). The core theory, typical in ANDA litigation over method-of-use patents, is that the proposed product label will instruct physicians and patients to use the drug in a manner that practices the claimed method. The complaint does not include the proposed label or a detailed claim chart.

’404 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of treating a human subject with [R]-2-amino-3-phenylpropylcarbamate (APC)... Defendant's proposed product is a generic version of solriamfetol (APC), and its labeling will allegedly instruct its use for treating conditions like excessive daytime sleepiness. ¶¶9, 36 col. 49:16-17
determining if the patient has moderate or severe renal impairment based on the estimated glomerular filtration rate (eGFR) of the subject... The proposed label will allegedly instruct or encourage physicians to assess a patient's renal function (eGFR) to determine the appropriate dose, as this is critical for safe administration. ¶¶33, 36 col. 49:21-24
(a) providing to a subject having an [eGFR for moderate impairment]... a first oral daily dose equivalent to 37.5 mg APC from day one to day n₁, ...wherein n₁ is an integer equal to or greater than 5... The proposed label will allegedly instruct a starting dose of 37.5 mg for moderately impaired patients for a period of at least five days before any escalation. ¶¶33, 36 col. 49:25-36
and a second oral daily dose equivalent to 75 mg APC... wherein the subject is not provided a daily dose exceeding... 75 mg APC... The proposed label will allegedly instruct an escalation to a maximum daily dose of 75 mg for moderately impaired patients. ¶¶33, 36 col. 49:32-38
(b) providing to a subject having an [eGFR for severe impairment]... an oral daily dose equivalent to 37.5 mg APC, wherein the subject is not provided a daily dose exceeding... 37.5 mg APC. The proposed label will allegedly instruct a maximum daily dose of 37.5 mg for severely impaired patients. ¶¶33, 36 col. 49:39-46
  • Identified Points of Contention:
    • Scope Questions: A central question will be whether Defendant’s proposed label instructions will contain the specific temporal limitation recited in claim 1 for moderately impaired patients (i.e., an initial dosing period where "n₁ is an integer equal to or greater than 5"). The dispute may focus on whether Defendant can "design around" the claim by, for example, instructing a different titration schedule (e.g., three days) that is still medically acceptable and approvable by the FDA.
    • Technical Questions: The case will likely turn on the doctrine of induced infringement. A key question will be whether the language in Defendant's final, FDA-approved label will inevitably lead prescribers to perform all steps of the claimed method. The analysis will focus on the specific instructions, warnings, and dosage tables included in the proposed product insert.

V. Key Claim Terms for Construction

  • The Term: "a first oral daily dose... from day one to day n₁... wherein n₁ is an integer equal to or greater than 5"
  • Context and Importance: This phrase defines the minimum duration of the initial, lower-dose treatment phase for moderately impaired patients before dose escalation. The infringement analysis for this patient population will depend entirely on whether Defendant's proposed label instructs or recommends a titration period that meets this "at least 5 days" requirement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: Parties seeking a broader view might argue that the purpose of the escalation is to allow for "tolerance development," which is not an inherently rigid process, suggesting the number is illustrative rather than strictly limiting. (’404 Patent, col. 3:9-12).
    • Evidence for a Narrower Interpretation: The claim language uses a precise numerical limitation ("equal to or greater than 5"). The patent specification repeatedly frames this specific, slow escalation scheme as a key feature of the invention for managing adverse effects, particularly for moderately impaired patients who require a more cautious approach than mildly impaired patients but can tolerate more than severely impaired patients. (’404 Patent, col. 51:40-47).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. The inducement claim is based on the allegation that Defendant, with knowledge of the ’404 patent, will encourage direct infringement by physicians and patients through the instructions for use, marketing, and promotional materials associated with its generic product upon FDA approval. (Compl. ¶36). The contributory infringement claim alleges the product is designed for an infringing use and lacks a substantial non-infringing use. (Compl. ¶37).
  • Willful Infringement: The complaint does not contain an explicit allegation of willful infringement. However, it does allege that Defendant's inducement would be intentional and with knowledge of the ’404 patent, stemming from the Paragraph IV notice. (Compl. ¶36). It also seeks a finding that the case is "exceptional" to justify an award of attorneys' fees under 35 U.S.C. § 285. (Compl. ¶40).

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

  • A core issue will be one of induced infringement: will the final, FDA-approved label for Defendant's generic solriamfetol product contain dosing instructions for patients with moderate and severe renal impairment that fall within the specific numerical ranges (e.g., eGFR, mg dose) and temporal limitations (e.g., "greater than 5" days) of Claim 1, thereby directly encouraging physicians to infringe?
  • A second key question will be one of enforceability and scope: can Defendant successfully argue that the claimed dosing regimen is invalid (e.g., obvious in light of prior pharmacokinetic principles), as asserted in its Paragraph IV certification, or that its proposed label successfully "designs around" the patent's claims with a different, non-infringing, yet medically sound and FDA-approvable, dosing instruction?