Grunenthal GmbH v. Hikma Pharmaceuticals USA Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Grünenthal GmbH (Germany)
  • Defendant: Hikma Pharmaceuticals USA Inc. (Delaware); Hikma Pharmaceuticals PLC (United Kingdom); Collegium Pharmaceutical, Inc. (Virginia)
  • Plaintiff’s Counsel: FBT Gibbons LLP
• Case Identification: 2:26-cv-00999, D.N.J., 02/02/2026
• Venue Allegations: Venue is alleged in New Jersey based on Defendant Hikma USA Inc.'s principal place of business and acts of infringement in the district, and Defendant Collegium Pharmaceutical, Inc.'s substantial and systematic business contacts, including sales, within the district.
• Core Dispute: Plaintiff alleges that Defendants' planned launch of an authorized generic version of the pain medication Nucynta® ER (tapentadol) will infringe two patents related to methods of using tapentadol for treating specific types of pain and for specific dosing regimens.
• Technical Context: The dispute is in the pharmaceutical sector and concerns tapentadol, a centrally-acting synthetic opioid analgesic used for managing moderate to severe chronic pain.
• Key Procedural History: The patents-in-suit are listed in the FDA's Orange Book for the branded drug Nucynta® ER. The case is a declaratory judgment action filed in anticipation of the launch of an "authorized generic" product by Hikma, which is being supplied by Collegium pursuant to an agreement between them. The complaint alleges that Collegium, the current New Drug Application (NDA) holder for Nucynta® ER, does not possess the right under its own license from Grünenthal to sublicense or authorize a generic launch by Hikma. This action does not arise under the Hatch-Waxman Act and involves no Paragraph IV certification.

Case Timeline

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

U.S. Patent No. 8,536,130 - "USE OF 1 PHENYL-3-DIMETHYLAMINO-PROPANE COMPOUNDS FOR TREATING NEUROPATHIC PAIN"

• Issued: September 17, 2013

The Invention Explained

• Problem Addressed: The patent’s background section describes the difficulty in treating neuropathic pain, noting that common analgesics are often ineffective or have significant, problematic side effects, creating a need for compounds with a better efficacy-to-side-effect profile for this specific condition (’130 Patent, col. 2:26-34).
• The Patented Solution: The invention is the use of the compound tapentadol—specifically the (1R,2R) stereoisomer—to treat neuropathic pain, and in particular, polyneuropathic pain such as that associated with diabetes. The patent asserts that tapentadol is "surprisingly particularly effective" for this type of pain, suggesting a specific utility beyond general analgesia ’130 Patent, col. 2:47-53
• Technical Importance: The invention identified a targeted therapeutic application for tapentadol in a hard-to-treat pain category, offering a potential alternative to existing therapies that were either less effective or carried a high burden of side effects ’130 Patent, col. 2:54-61

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶69
• Essential elements of Claim 1:
  • A method of treating polyneuropathic pain in a subject suffering therefrom,
  • said method comprising administering to said subject an effective polyneuropathic pain inhibiting amount of
  • (1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)phenol [tapentadol] or a pharmaceutically acceptable salt thereof.
• The complaint reserves the right to assert additional claims Compl. ¶69

U.S. Patent No. 11,344,512 - "TITRATION OF TAPENTADOL"

• Issued: May 31, 2022

The Invention Explained

• Problem Addressed: The patent background states that while tapentadol is a well-tolerated analgesic, initiating treatment can cause "nuisance adverse events such as somnolence," which may lead to patients discontinuing the therapy (’512 Patent, col. 2:7-12).
• The Patented Solution: The invention provides a specific dosing regimen, or "titration," where treatment with tapentadol begins at a "comparatively low dose" and is then "successively increasing the dose." This gradual increase is purported to improve the drug's tolerability and reduce side effects like somnolence, without compromising its pain-relieving efficacy ’512 Patent, col. 2:58-63
• Technical Importance: This method provides a practical clinical strategy to improve patient compliance and therapeutic outcomes by managing the common initial side effects of a potent analgesic, a significant challenge in the field of pain management ’512 Patent, col. 2:16-24

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶85
• Essential elements of Claim 1:
  • A method of treating pain with a lower incidence of somnolence in a subject,
  • comprising orally administering a three-step dose-escalation regimen of tapentadol:
  • (i) a first dose of 50 mg±5% or 100 mg±5% twice daily (bid) for a first interval of at least 1-3 days;
  • (ii) a second, higher dose of 100 mg±5% or 150 mg±5% bid, calculated by increasing the first dose by 50 mg, for a second interval of at least 3-11 days; and
  • (iii) a third, still higher dose of 150 mg±5% or 200 mg±5% bid, calculated by increasing the second dose by 50 mg, for a third interval of at least 3-14 days.
• The complaint reserves the right to assert additional claims Compl. ¶85

III. The Accused Instrumentality

Product Identification

• The "Hikma Product," identified as an authorized generic version of Nucynta® ER (tapentadol) extended-release tablets Compl. ¶¶2, 31-32

Functionality and Market Context

• The Hikma Product is an extended-release tablet containing tapentadol, to be offered in 50 mg, 100 mg, 150 mg, 200 mg, and 250 mg strengths Compl. ¶43 The complaint alleges that the product's labeling will be "identical to the current label for Nucynta® ER in all material respects except for the tradename and corporate details" Compl. ¶43 The indicated uses will therefore include the "management of moderate to severe chronic pain in adults and neuropathic pain associated with DPN [diabetic peripheral neuropathy] in adults" Compl. ¶43 As an "authorized generic," the product is the same as the branded drug and will be launched into the U.S. market with the permission of Collegium, the NDA holder, to compete with the branded version Compl. ¶¶29, 33 No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

U.S. Patent 8,536,130 Infringement Allegations

• Identified Points of Contention:
  • Scope Question: A potential issue for the court is whether the accused product's label indication for "neuropathic pain associated with DPN in adults" Compl. ¶43 falls within the scope of the claim term "polyneuropathic pain." The patent specification, however, repeatedly identifies diabetic neuropathic pain as a preferred type of polyneuropathic pain to be treated, which may support the plaintiff's position on this point ’130 Patent, Abstract col. 5:9-15

U.S. Patent 11,344,512 Infringement Allegations

The complaint does not provide the specific dosing instructions that will appear on the Hikma Product label. The infringement theory is predicated on the allegation that the label, being identical to that of Nucynta® ER, will direct a use that meets the claimed titration regimen Compl. ¶¶43, 85

• Identified Points of Contention:
  • Evidentiary Question: A central evidentiary question for the court will be the exact content of the Hikma Product's final, approved label. The complaint's infringement theory for the ’512 patent is entirely dependent on the specific dosing instructions that will be included in this label, which was not provided with the complaint Compl. ¶¶43, 85
  • Technical/Scope Question: If the label is produced, a key question will be whether the titration schedule it recommends aligns with the specific dosage amounts, escalation calculations (e.g., "increasing said first dose by 50 mg"), and administration intervals (e.g., "at least 1-3 days") required by the claim language. Any deviation could be a basis for a non-infringement argument.

V. Key Claim Terms for Construction

• Term: "polyneuropathic pain" (from Claim 1 of the ’130 Patent)

• Context and Importance: This term's construction is critical because the accused product's label will be for "neuropathic pain associated with DPN" Compl. ¶43 The infringement analysis will depend on whether this specific indication is considered a type of "polyneuropathic pain." Practitioners may focus on this term to determine if there is a mismatch between the claim scope and the accused activity.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent specification explicitly and repeatedly groups these concepts, stating its methods are for "treating neuropathic pain, preferably polyneuropathic pain, also preferably diabetic neuropathic pain, more preferably diabetic peripheral neuropathic pain" ’130 Patent, col. 5:9-13 This language suggests diabetic neuropathy is a subset of polyneuropathy.
  • Evidence for a Narrower Interpretation: The defense could argue that the title and abstract, which single out "neuropathic pain" and "diabetic peripheral neuropathy," suggest the invention is directed at distinct conditions. This argument may be countered by the more detailed description in the specification.

• Term: "a lower incidence of somnolence" (from the preamble of Claim 1 of the ’512 Patent)

• Context and Importance: This preamble language states the objective and result of the claimed method. Its construction will be critical to determining whether it imposes a separate, substantive limitation on the claim that the plaintiff must prove. Practitioners may focus on this term because it raises the question of whether simply performing the titration steps is sufficient for infringement, or if an actual, measurable reduction in somnolence must also be demonstrated.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation (i.e., not a separate limitation): A plaintiff may argue the patent specification presents the claimed titration steps as the way to achieve a lower incidence of somnolence, effectively defining the result by the performance of the steps. The patent's clinical data is offered as proof that the method inherently works as stated, suggesting that performing the steps necessarily achieves the result ’512 Patent, col. 32:45-56 FIGS. 5-6
  • Evidence for a Narrower Interpretation (i.e., a separate limitation): A defendant may argue that this phrase requires proof of a functional outcome. The specification compares studies "with and without dose titration" to show the effect ’512 Patent, col. 32:7-11, suggesting that "lower incidence" must be proven relative to a specific comparator, such as non-titrated administration.

VI. Other Allegations

• Indirect Infringement: The complaint's primary allegations are for indirect infringement. It alleges that Hikma will induce infringement by marketing its product with labeling that instructs physicians and patients to perform the patented methods Compl. ¶¶70-73, 86-89 It further alleges that Collegium will induce and contribute to this infringement by knowingly supplying the product to Hikma under an authorized generic agreement for this express purpose Compl. ¶¶99-100, 115-116 Contributory infringement is also pled on the basis that the product and its labeling are especially made for an infringing use and have no substantial non-infringing use Compl. ¶¶74, 90, 106, 122
• Willful Infringement: Willfulness is alleged based on Defendants' knowledge of the patents-in-suit, which are listed in the FDA's Orange Book for Nucynta® ER Compl. ¶¶55, 61, 66, 82, 98, 114 The complaint also asserts that Defendants lack a reasonable basis to believe they are not infringing, in part because Collegium is allegedly not authorized to sublicense its rights to Hikma Compl. ¶¶76, 92, 108, 124

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

1. A threshold issue will be one of contractual authority and standing: Does Collegium’s license from Grünenthal permit it to authorize Hikma to market a generic version of Nucynta® ER? The complaint’s assertion that Collegium lacks the right to sublicense raises a fundamental question about the legality of the entire commercial arrangement, which may be dispositive before reaching the patent merits.

2. A central evidentiary question for the ’512 patent will be one of instructed use: Will the final, approved labeling for the Hikma Product direct a specific multi-step titration regimen that falls squarely within the dosage and timing limitations of the asserted claims? The infringement case for this patent hinges on the precise content of a label that is not yet part of the record.

3. A key question for the ’130 patent will be one of definitional scope: Will the court construe the claim term "polyneuropathic pain" to encompass the accused product's labeled indication for "neuropathic pain associated with diabetic peripheral neuropathy," particularly where the patent's own specification appears to treat the latter as a prime example of the former?