Xeris Pharma Inc v. Somerset Therap LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Xeris Pharmaceuticals, Inc. (Delaware) and Strongbridge Dublin Limited (Ireland)
  • Defendant: Somerset Therapeutics, LLC (Delaware); Somerset Pharma, LLC (Delaware); Somerset Therapeutics Private Limited (India); Odin Pharmaceuticals, LLC (Delaware); Torrent Pharma Inc. (Delaware); and Torrent Pharmaceuticals Limited (India)
  • Plaintiff's Counsel: FBT Gibbons LLP
• Case Identification: 3:26-cv-02044, D.N.J., 02/26/2026
• Venue Allegations: Venue is alleged in the District of New Jersey based on the Defendants maintaining principal places of business within the district (Somerset, NJ and Basking Ridge, NJ) and submitting their respective Abbreviated New Drug Applications (ANDAs) from these locations.
• Core Dispute: Plaintiff alleges that Defendants' submission of ANDAs to the U.S. Food and Drug Administration for generic versions of Plaintiff's RECORLEV® (levoketoconazole) product constitutes an act of infringement of four U.S. patents directed to methods of treatment.
• Technical Context: The technology relates to methods of using levoketoconazole, an oral cortisol synthesis inhibitor, for treating Cushing's syndrome, a rare endocrine disorder caused by chronic elevated cortisol exposure.
• Key Procedural History: This action was filed under 35 U.S.C. § 271(e)(2) following Plaintiffs' receipt of Paragraph IV certification notice letters from the Somerset and Torrent defendant groups regarding their respective ANDA filings. The complaint was filed within the 45-day statutory window, which triggers an automatic 30-month stay on FDA approval of the Defendants' generic products.

Case Timeline

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

U.S. Patent No. 11,020,393 - Methods of Treating Disease With Levoketoconazole

The Invention Explained

• Problem Addressed: The patent describes Cushing's disease as a rare and potentially lethal endocrine disorder caused by excessive cortisol exposure ʼ393 Patent, col. 1:9-13 It notes that existing treatments like ketoconazole carry significant risks, including liver toxicity and drug-drug interactions, reflecting a persistent unmet need for improved therapies ʼ393 Patent, col. 1:41-51
• The Patented Solution: The invention is a method of treatment using levoketoconazole, which is the specific 2S,4R enantiomer of ketoconazole ʼ393 Patent, col. 1:51-54 The patent discloses that this specific enantiomer more potently inhibits cortisol synthesis ʼ393 Patent, col. 1:56-58 The claimed methods involve administering levoketoconazole according to a specific dose-titration scheme, particularly when co-administered with other drugs (such as metformin), and monitoring for specific dose-limiting events to manage safety and efficacy ʼ393 Patent, abstract ʼ393 Patent, col. 2:5-17
• Technical Importance: By isolating a single, more potent enantiomer, the invention aimed to provide a more targeted therapeutic approach to cortisol synthesis inhibition, potentially improving the benefit-risk profile compared to the racemic mixture of ketoconazole ʼ393 Patent, col. 1:51-60

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶87 Compl. ¶159
• Essential elements of Claim 1:
  • A method of treating persistent or recurrent Cushing's syndrome in a subject who also has type 2 diabetes mellitus and is being co-administered metformin to improve glycemic control.
  • The method comprises administering a therapeutically effective amount of levoketoconazole, where the amount is determined via a titration scheme.
  • The method further comprises, during the titration, monitoring the subject for a dose limiting event, specified as a decreased fasting glucose level, abnormal kidney function, and/or a low Vitamin B-12 level.
  • If the subject experiences such a dose limiting event, the method comprises reducing the amount of metformin administered to the subject.
• The complaint does not explicitly reserve the right to assert dependent claims but makes general allegations covering one or more claims of the patent Compl. ¶88 Compl. ¶160

U.S. Patent No. 11,278,547 - Methods of Treating Disease With Levoketoconazole

The Invention Explained

• Problem Addressed: The ʼ547 Patent addresses the same technical problem as the '393 Patent: the need for safer and more effective treatments for Cushing's syndrome ʼ547 Patent, col. 1:10-52
• The Patented Solution: The solution is substantively identical to that of the '393 Patent, centering on the administration of the levoketoconazole enantiomer using a titration and monitoring protocol to manage co-administered drugs like metformin ʼ547 Patent, col. 1:53-61 ʼ547 Patent, abstract The claims of the '547 Patent are directed to a specific sub-population of patients.
• Technical Importance: As with the '393 Patent, the technical contribution relates to the use of a specific, more potent enantiomer to provide a more targeted therapy ʼ547 Patent, col. 1:53-61

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶105 Compl. ¶177
• Essential elements of Claim 1:
  • A method of treating Cushing's syndrome in a subject who has type 2 diabetes mellitus, is being co-administered metformin, and, critically, "has had previous surgery or radiation to treat the subject's Cushing syndrome."
  • The method comprises administering levoketoconazole determined via a titration scheme.
  • The method includes monitoring for the same dose-limiting events as in the '393 Patent (decreased fasting glucose, abnormal kidney function, and/or low Vitamin B-12).
  • If a dose limiting event is experienced, the method requires reducing the amount of metformin administered.
• The complaint does not explicitly reserve the right to assert dependent claims Compl. ¶106 Compl. ¶178

U.S. Patent No. 11,903,940 - Methods of Treating Disease With Levoketoconazole

• Patent Identification: U.S. Patent No. 11,903,940, "Methods of Treating Disease With Levoketoconazole," issued February 20, 2024.
• Technology Synopsis: This patent claims methods for treating Cushing's syndrome with levoketoconazole in patients who are also taking an organic cation transporter 2 (OCT2) substrate. The method involves titrating the levoketoconazole dose, monitoring for adverse events caused by increased exposure to the OCT2 substrate, and reducing the dosage of the OCT2 substrate if such an event occurs ʼ940 Patent, abstract ʼ940 Patent, col. 1:4-18
• Asserted Claims: Independent claim 1 Compl. ¶123 Compl. ¶195
• Accused Features: The complaint alleges that Defendants' proposed product labels will instruct for the co-administration of their generic levoketoconazole with metformin (an OCT2 substrate) and direct healthcare providers to monitor for adverse events and adjust metformin dosage accordingly Compl. ¶124 Compl. ¶125 Compl. ¶196 Compl. ¶197

U.S. Patent No. 12,377,096 - Methods of Treating Disease With Levoketoconazole

• Patent Identification: U.S. Patent No. 12,377,096, "Methods of Treating Disease With Levoketoconazole," issued August 5, 2025.
• Technology Synopsis: This patent is similar to the '940 patent but is directed at methods of treating Cushing's syndrome with levoketoconazole in patients who are co-administered a multidrug and toxin extrusion transporter 1 (MATE1) substrate. The claimed method requires dose titration of levoketoconazole, monitoring for dose-limiting events related to increased MATE1 substrate exposure, and reducing the MATE1 substrate dose in response ʼ096 Patent, abstract ʼ096 Patent, col. 1:4-18
• Asserted Claims: Independent claim 1 Compl. ¶141 Compl. ¶213
• Accused Features: The infringement allegation is based on the proposed product labels, which will allegedly instruct for use with metformin (a MATE1 substrate) and direct monitoring and dosage adjustments that fall within the scope of the claims Compl. ¶142 Compl. ¶143 Compl. ¶214 Compl. ¶215

III. The Accused Instrumentality

Product Identification

• The accused instrumentalities are the generic levoketoconazole 150 mg oral tablets for which the Somerset and Torrent defendant groups have filed ANDAs seeking FDA approval Compl. ¶66 Compl. ¶73 Compl. ¶76 Compl. ¶83 These are identified as the "Somerset ANDA Product" (ANDA No. 221137) and the "Torrent ANDA Product" (ANDA No. 220357) Compl. ¶66 Compl. ¶76

Functionality and Market Context

• The infringement allegations are not based on the composition of the tablets themselves, but on the methods of use that will allegedly be instructed on the products' proposed labeling Compl. ¶88 Compl. ¶106 The complaint alleges that the proposed labels will direct healthcare providers to prescribe the generic products for treating Cushing's syndrome in patients who are also taking metformin, to use a dose titration scheme for levoketoconazole, to monitor for specific dose-limiting events, and to adjust the metformin dosage in response Compl. ¶89 Compl. ¶107 Compl. ¶125 Compl. ¶143
• The defendants' products are generic versions of Plaintiffs' RECORLEV® drug, which the complaint describes as a "groundbreaking oral cortisol synthesis inhibitor" for a "rare and serious" condition Compl. ¶2 Compl. ¶3 The defendants allegedly intend to commercially manufacture and sell their products upon FDA approval, which would directly compete with and displace sales of RECORLEV® Compl. ¶19 Compl. ¶26 Compl. ¶38 Compl. ¶54

IV. Analysis of Infringement Allegations

The complaint alleges that the use of the Somerset ANDA Product and the Torrent ANDA Product, in accordance with their proposed labeling, will infringe the asserted patents Compl. ¶91 Compl. ¶109 Compl. ¶127 Compl. ¶145 Compl. ¶163 Compl. ¶181 Compl. ¶199 Compl. ¶217 The core of the infringement theory is that healthcare providers who prescribe the generic drugs according to the label instructions will directly infringe the method claims, and that the defendants will induce this infringement Compl. ¶99 Compl. ¶117

U.S. Patent No. 11,020,393 Infringement Allegations

U.S. Patent No. 11,278,547 Infringement Allegations

No probative visual evidence provided in complaint.

Identified Points of Contention

• Direct Infringement Standard: Since the asserted claims are method claims involving actions by both a healthcare provider (monitoring, adjusting dosage) and a patient (taking the medication), a central issue will be direct infringement by a single actor. The complaint alleges that prescribing healthcare providers will "direct or control" the performance of all steps Compl. ¶89 Compl. ¶107 This raises the question of whether the physician-patient relationship and the instructions on the proposed label are sufficient to meet the "direction or control" standard for single-party liability.
• Label Language vs. Claim Language: The infringement case is based entirely on the text of the defendants' proposed product labels, which are not included in the complaint. A primary point of contention will be whether the language on the final approved labels requires or merely suggests the steps claimed in the patents. Defendants may argue that their labels allow for non-infringing uses, defeating the inducement claim and complicating the direct infringement theory.

V. Key Claim Terms for Construction

• The Term: "titration scheme"
• Context and Importance: The asserted claims require that the amount of levoketoconazole be determined via a "titration scheme." The infringement analysis will depend on whether the dosing instructions in the accused labels fall within the scope of this term. Practitioners may focus on this term because the patents' dependent claims and specification describe a particular multi-step cycle of dose increases and tolerance checks ʼ393 Patent, claim 8 ʼ393 Patent, col. 11:1-14
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The independent claims do not define the "titration scheme" with structural limitations, suggesting a functional definition related to adjusting dosage over time to achieve a therapeutic effect.
  • Evidence for a Narrower Interpretation: Dependent claim 8 of the '393 Patent recites a specific multi-step titration cycle involving a "first time period," an "incremental value of 150 mg daily," and a determination of tolerance ʼ393 Patent, col. 25:28-48 A defendant could argue that these limitations from a dependent claim and the corresponding description in the specification should inform or limit the scope of the term in the independent claim.
• The Term: "dose limiting event"
• Context and Importance: The claims require monitoring for and acting upon a "dose limiting event," which is defined as a specific list of clinical outcomes ("decreased fasting glucose level, abnormal kidney function, and/or a low Vitamin B-12 level"). The scope of these clinical terms will be critical, as the instructions on the accused labels must direct a response to events that fall within the construed definition.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim uses "and/or," which may support an interpretation that monitoring for any one of the listed events is sufficient to meet the limitation.
  • Evidence for a Narrower Interpretation: The specification provides more specific clinical definitions, such as defining "abnormal kidney function" by a specific estimated glomerular filtration rate (eGFR) value ("less than 30 mL/min/1.73 m²") ʼ393 Patent, col. 13:42-45 A defendant may argue that the term "dose limiting event" is not met unless the label instructs action based on these more precise clinical thresholds described in the patent's detailed description.

VI. Other Allegations

• Indirect Infringement: The complaint alleges active inducement of infringement against all defendants. The factual basis is the allegation that defendants will, with specific intent, sell their generic products with labels that provide instructions for healthcare providers and patients to perform the patented methods Compl. ¶99 Compl. ¶117 Compl. ¶135 Compl. ¶153
• Willful Infringement: While the term "willful" is not used, the complaint lays the groundwork for such a claim by alleging that defendants had "actual and constructive notice" of the asserted patents prior to filing their ANDAs, at least because the patents are listed in the FDA's Orange Book for RECORLEV® Compl. ¶97 Compl. ¶115 Compl. ¶133 Compl. ¶151 This alleged pre-suit knowledge is also used to support a claim that the case is "exceptional" under 35 U.S.C. § 285, entitling Plaintiffs to attorneys' fees Compl. ¶102 Compl. ¶120 Compl. ¶138 Compl. ¶156

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

• A primary evidentiary question will be one of instructional precision: Does the precise language of the Defendants' proposed drug labels direct, recommend, or merely inform prescribers about the patented methods? The case will likely depend on whether the label's text is construed as a mandate to perform the claimed steps of titration, monitoring for specific events, and responsive dose adjustment.
• A central legal issue will be one of divided infringement: Can Plaintiffs prove that a single actor-the prescribing physician-"directs or controls" every step of the claimed methods, including the patient's self-administration of the drug, to satisfy the standard for direct infringement under current case law?
• The outcome may also turn on a key question of claim scope: Will the term "titration scheme" be given a broad, functional meaning, or will it be limited to the specific dose-escalation protocols detailed in the patent specifications? Similarly, will "dose limiting event" be construed to require the specific clinical thresholds described in the patents, potentially creating a gap between the claim scope and the label's instructions?