DCT

1:26-cv-00981

Eli Lilly & Co v. Hikma Pharma USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: Eli Lilly & Co. v. Hikma Pharmaceuticals USA Inc., 1:26-cv-00981, D. Del., 08/13/2026
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Hikma is a corporation organized and existing under the laws of Delaware and therefore resides in the district for purposes of venue.
  • Core Dispute: Plaintiff alleges that Defendant's submission of Abbreviated New Drug Applications (ANDAs) to the FDA for generic versions of Mounjaro® and Zepbound® (tirzepatide) infringes ten U.S. patents covering the tirzepatide compound, pharmaceutical formulations, and methods of use.
  • Technical Context: The lawsuit concerns tirzepatide, a dual GIP/GLP-1 receptor co-agonist used for glycemic control in type 2 diabetes and for chronic weight management, a significant and growing pharmaceutical market.
  • Key Procedural History: This action arises under the Hatch-Waxman Act, triggered by Defendant's submission of ANDA Nos. 220241 and 220324 to the FDA. Defendant provided Plaintiff with notice of its ANDA filings, which included Paragraph IV certifications asserting that the patents-in-suit are invalid, unenforceable, or will not be infringed by the proposed generic products.

Case Timeline

Date Event
2016-10-25 U.S. Patent No. 9,474,780 issues
2018-06-22 Earliest priority date for '820 and '623 Patents
2018-07-23 Earliest priority date for '987 Patent
2022-05-13 FDA approves Plaintiff's Mounjaro® (tirzepatide)
2022-06-14 U.S. Patent No. 11,357,820 issues
2023-11-08 FDA approves Plaintiff's Zepbound® (tirzepatide)
2024-03-05 U.S. Patent No. 11,918,623 issues
2025-05-13 U.S. Patent No. 12,295,987 issues
2025-07-01 U.S. Patent No. 12,343,382 issues
2025-10-28 U.S. Patent No. 12,453,755 issues
2025-10-28 U.S. Patent No. 12,453,756 issues
2025-10-28 U.S. Patent No. 12,453,758 issues
2026-05-05 U.S. Patent No. 12,616,740 issues
2026-05-19 U.S. Patent No. 12,629,404 issues
2026-07-06 Defendant sends first ANDA Notice Letter to Plaintiff
2026-08-10 Defendant sends second ANDA Notice Letter to Plaintiff
2026-08-13 Complaint Filing Date

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

U.S. Patent No. 9,474,780

  • Patent Identification: U.S. Patent No. 9,474,780, titled "GIP and GLP-1 Co-agonist Compounds," issued October 25, 2016.

The Invention Explained

  • Problem Addressed: The patent addresses the need for improved treatments for type 2 diabetes mellitus (T2D), a condition characterized by high blood glucose levels caused by insulin resistance US 9,474,780, col. 1:19-23 The patent notes that existing incretin mimetics utilize only a single mechanism of action and a dual-mechanism compound is needed US 9,474,780, col. 1:15-18
  • The Patented Solution: The invention is a novel peptide compound that acts as a co-agonist for both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors US 9,474,780, col. 2:33-36 This dual action aims to provide more effective glycemic control. The core of the invention is a specific peptide sequence with chemical modifications designed to enhance its therapeutic properties and extend its half-life US 9,474,780, col. 3:6-21
  • Technical Importance: The invention represents a novel therapeutic approach for T2D by combining the actions of two key incretin hormones, GIP and GLP-1, into a single molecule to achieve superior glucose-lowering effects compared to single-agonist therapies.

Key Claims at a Glance

  • The complaint asserts at least Claim 1 Compl. ¶50
  • Claim 1 is a composition of matter claim covering:
    • A compound of a specific 39-amino-acid formula: YX1EGTFTSDYSIX2LDKIAQKAX3VQWLIAGGPSSGAPPPS.
    • Wherein specific amino acids are defined (X1 is Aib; X2 is Aib; X3 is Phe or 1-Nal).
    • Wherein the lysine (K) at position 20 is chemically modified with a specific fatty acid-linker moiety.
    • Wherein the C-terminal amino acid is optionally amidated.
    • Or a pharmaceutically acceptable salt thereof.
  • The complaint reserves the right to assert infringement of other claims Compl. ¶52

U.S. Patent No. 11,357,820

  • Patent Identification: U.S. Patent No. 11,357,820, titled "GIP/GLP1 Agonist Compositions," issued June 14, 2022.

The Invention Explained

  • Problem Addressed: The patent seeks to create compositions of tirzepatide that have acceptable stability and provide an acceptable patient injection site experience US 11,357,820, col. 1:26-29 The patent notes that some excipients like citrate can be associated with painful stinging at the injection site US 11,357,820, col. 3:11-14
  • The Patented Solution: The invention is a specific pharmaceutical formulation of tirzepatide that includes sodium chloride (NaCl) as a tonicity agent and dibasic sodium phosphate as a buffer US 11,357,820, col. 1:3-8 US 11,357,820, col. 1:29-33 This combination is described as providing "commercially acceptable shelf-life stability, in-use stability, and is associated with acceptable patient injection site experience" US 11,357,820, col. 1:4-8
  • Technical Importance: This invention provided a stable, patient-friendly liquid formulation for tirzepatide, which is critical for its commercial use as a subcutaneously injected drug.

Key Claims at a Glance

  • The complaint asserts at least Claim 1 Compl. ¶67
  • Claim 1 is a composition of matter claim covering:
    • A pharmaceutical composition comprising tirzepatide, or a pharmaceutically acceptable salt thereof.
    • NaCl at a concentration from 6.2 mg/mL to 9.5 mg/mL.
    • And dibasic sodium phosphate.
  • The complaint reserves the right to assert infringement of other claims Compl. ¶69

Multi-Patent Capsule: U.S. Patent No. 11,918,623

  • Patent Identification: U.S. Patent No. 11,918,623, titled "GIP/GLP1 Agonist Compositions," issued March 5, 2024 Compl. ¶24
  • Technology Synopsis: This patent claims a method of treating obesity by administering a specific pharmaceutical composition of tirzepatide. The composition includes defined concentration ranges for tirzepatide, dibasic sodium phosphate, NaCl, and optionally phenol, addressing the need for effective and stable formulations for weight management therapy US 11,918,623, col. 1:31-35 US 11,918,623, claim 1
  • Asserted Claims: At least Claim 1 is asserted Compl. ¶84
  • Accused Features: Hikma's proposed labeling for its generic Zepbound® product, which allegedly instructs and encourages treating obesity with a composition meeting the claim's parameters, is accused of infringement Compl. ¶85

Multi-Patent Capsule: U.S. Patent No. 12,295,987

  • Patent Identification: U.S. Patent No. 12,295,987, titled "Methods of Using a GIP/GLP1 Co-agonist for Diabetes," issued May 13, 2025 Compl. ¶26
  • Technology Synopsis: This patent claims a method of treating T2D using a specific dose-titration regimen for a GIP:GLP-1 peptide. The invention is designed to manage gastrointestinal side effects while enabling patients to reach effective therapeutic doses, a known challenge with GLP-1 treatments US 12,295,987, col. 2:1-5 The method involves administering a sequence of four escalating doses over a minimum period of time.
  • Asserted Claims: At least Claim 1 is asserted Compl. ¶103
  • Accused Features: The proposed labeling for Hikma's generic Mounjaro® product is accused of infringing by allegedly instructing and encouraging the claimed dose-escalation method for treating T2D Compl. ¶104

Multi-Patent Capsule: U.S. Patent No. 12,343,382

  • Patent Identification: U.S. Patent No. 12,343,382, titled "Methods of Using a GIP/GLP1 Co-agonist for Therapy," issued July 1, 2025 Compl. ¶28
  • Technology Synopsis: This patent covers methods for treating T2D and improving weight management using a dose-escalation regimen for tirzepatide. The regimen involves administering an "escalation dose" for a period, followed by a "maintenance dose," with specific dose amounts provided for each phase US 12,343,382, col. 2:3-11
  • Asserted Claims: At least Claims 1 and 11 are asserted Compl. ¶¶122, 124
  • Accused Features: Hikma's proposed labeling for its generic products is accused of infringing by instructing the claimed dose-escalation and maintenance methods for treating T2D and improving weight management Compl. ¶¶123, 125

Multi-Patent Capsule: U.S. Patent No. 12,453,755

  • Patent Identification: U.S. Patent No. 12,453,755, titled "GIP/GLP1 Agonist Compositions," issued October 28, 2025 Compl. ¶30
  • Technology Synopsis: This patent claims a method of treating diabetes by administering a pharmaceutical composition containing tirzepatide within specific concentration ranges for the active ingredient and excipients, including dibasic sodium phosphate, NaCl, and optional phenol. This formulation is designed to provide a stable and effective treatment US 12,453,755, col. 1:26-30
  • Asserted Claims: At least Claim 1 is asserted Compl. ¶145
  • Accused Features: The proposed labeling for Hikma's generic Mounjaro® is accused of infringing by instructing the use of a composition that allegedly meets the claimed parameters for treating diabetes Compl. ¶146

Multi-Patent Capsule: U.S. Patent No. 12,453,756

  • Patent Identification: U.S. Patent No. 12,453,756, titled "GIP/GLP1 Agonist Compositions," issued October 28, 2025 Compl. ¶32
  • Technology Synopsis: This patent claims a specific pharmaceutical composition of tirzepatide comprising NaCl within a defined concentration range and having a pH within a defined range. The invention provides a stable formulation for subcutaneous injection US 12,453,756, col. 1:4-8
  • Asserted Claims: At least Claim 1 is asserted Compl. ¶164
  • Accused Features: Hikma's Proposed ANDA Products are accused of being pharmaceutical compositions that meet the claimed parameters for tirzepatide, NaCl concentration, and pH range Compl. ¶165

Multi-Patent Capsule: U.S. Patent No. 12,453,758

  • Patent Identification: U.S. Patent No. 12,453,758, titled "Methods of Using a GIP/GLP1 Co-agonist for Diabetes," issued October 28, 2025 Compl. ¶34
  • Technology Synopsis: This patent claims a method for improving weight management using a specific four-step dose-escalation regimen of a GIP:GLP-1 peptide. The method is designed to optimize therapeutic benefit while managing potential side effects associated with this class of drugs US 12,453,758, col. 2:1-5
  • Asserted Claims: At least Claim 1 is asserted Compl. ¶181
  • Accused Features: The proposed labeling for Hikma's generic Zepbound® product is accused of infringing by instructing the claimed dose-escalation method for improving weight management Compl. ¶182

Multi-Patent Capsule: U.S. Patent No. 12,616,740

  • Patent Identification: U.S. Patent No. 12,616,740, titled "Methods of Using a GIP/GLP1 Co-agonist for Therapy," issued May 5, 2026 Compl. ¶36
  • Technology Synopsis: This patent covers methods for treating T2D and obesity by administering tirzepatide in a specific once-weekly dose-escalation and maintenance regimen. The method starts with a 2.5 mg dose and increases by 2.5 mg increments to a maintenance dose of 5, 10, or 15 mg US 12,616,740, col. 2:3-11
  • Asserted Claims: At least Claims 1 and 6 are asserted Compl. ¶¶200, 202
  • Accused Features: Hikma's proposed labeling is accused of infringing by instructing the claimed dose-escalation and maintenance methods for treating T2D and obesity Compl. ¶¶201, 203

Multi-Patent Capsule: U.S. Patent No. 12,629,404

  • Patent Identification: U.S. Patent No. 12,629,404, titled "GIP/GLP1 Agonist Compositions," issued May 19, 2026 Compl. ¶38
  • Technology Synopsis: This patent claims a preservative-free pharmaceutical composition of tirzepatide containing NaCl and having a specific pH range. The invention aims to provide a stable, single-use formulation suitable for subcutaneous injection US 12,629,404, col. 1:4-8
  • Asserted Claims: At least Claim 1 is asserted Compl. ¶223
  • Accused Features: Hikma's Proposed ANDA Products are accused of being compositions that meet the claimed parameters, including being free of preservative Compl. ¶224

III. The Accused Instrumentality

  • Product Identification: The accused instrumentalities are Defendant Hikma's "Proposed ANDA Products," which are generic versions of Mounjaro® and Zepbound® autoinjectors in various strengths Compl. ¶1 These products are identified as arising from ANDA Nos. 220241 and 220324 Compl. ¶1
  • Functionality and Market Context:
    • The complaint alleges that Hikma's Proposed ANDA Products contain tirzepatide as the active pharmaceutical ingredient Compl. ¶44 The products are intended to be generic competitors to Lilly's Mounjaro® and Zepbound® products upon FDA approval Compl. ¶1
    • The functionality of the accused products is to serve as bioequivalent versions of the branded drugs, used for improving glycemic control in adults and pediatric patients with T2D, and for chronic weight management in adults with obesity or overweight with comorbid conditions Compl. ¶1 The complaint alleges that Hikma's ANDAs rely on the NDAs for Mounjaro® and Zepbound® and contain data demonstrating bioequivalence Compl. ¶45

IV. Analysis of Infringement Allegations

'780 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A compound of Formula: YX1EGTFTSDYSIX2LDKIAQKAX3VQWLIAGGPSSGAPPPS;... The complaint alleges that Hikma's Proposed ANDA Products contain tirzepatide, which is a compound with the structural formula corresponding to the claim. ¶51 US 9,474,780, claim 1
...wherein X1 is Aib; X2 is Aib;... Hikma's Proposed ANDA Products contain tirzepatide, which incorporates Aib at the corresponding positions. The complaint includes a structural diagram showing this. ¶51 US 9,474,780, claim 1
...K at position 20 is chemically modified through conjugation to the epsilon-amino group of the K side-chain with ([2-(2-Amino-ethoxy)-ethoxy]-acetyl)2-(yGlu)a-CO-(CH2)b-CO2H wherein a is 1 to 2 and b is 10 to 20;... The structural formula of tirzepatide provided in the complaint shows the claimed chemical modification at position 20. ¶51 US 9,474,780, claim 1
...or a pharmaceutically acceptable salt thereof. The complaint alleges infringement by products containing tirzepatide or its salts. ¶50 US 9,474,780, claim 1
  • Visual Evidence: The complaint provides a chemical structure diagram of tirzepatide, which it alleges is the compound covered by Claim 1 of the '780 Patent (Compl. ¶51).
  • Identified Points of Contention:
    • Structural Identity: The central question for direct infringement will be a factual determination of whether the tirzepatide compound in Hikma's Proposed ANDA Products is identical to the compound defined by the specific formula and modifications in Claim 1 of the '780 Patent. The complaint's direct allegation and inclusion of a structural diagram suggest Lilly's position is that they are identical (Compl. ¶51).
    • Scope Questions: A potential point of contention could be the interpretation of "pharmaceutically acceptable salt thereof," and whether the specific salt form used by Hikma, if any, falls within the claim's scope.

'820 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A pharmaceutical composition comprising tirzepatide, or a pharmaceutically acceptable salt thereof; Hikma's Proposed ANDA Products are alleged to be pharmaceutical compositions that comprise tirzepatide. ¶68 col. 1:29-30
NaCl at a concentration from 6.2 mg/mL to 9.5 mg/mL; The complaint alleges that Hikma's proposed products contain NaCl at a concentration within the claimed range. ¶68 col. 1:31-32
and dibasic sodium phosphate. The complaint alleges that Hikma's proposed products contain dibasic sodium phosphate. ¶68 col. 1:32-33
  • Identified Points of Contention:
    • Technical Questions: Infringement will depend on whether Hikma's proposed formulation contains the three required components (tirzepatide, NaCl, and dibasic sodium phosphate) and whether the NaCl concentration falls strictly within the 6.2 mg/mL to 9.5 mg/mL range. This will be a question of fact based on the contents of Hikma's ANDA.
    • Scope Questions: A potential dispute may arise over the precise chemical form of "dibasic sodium phosphate" required by the claim and whether the form used in Hikma's product (e.g., anhydrous, heptahydrate) meets that definition as construed by the court (US 11,357,820, col. 4:60-63).

V. Key Claim Terms for Construction

For '780 Patent

  • The Term: "pharmaceutically acceptable salt thereof"
  • Context and Importance: This term is critical because infringement can be found if Hikma's product contains either the base tirzepatide compound or a salt form. The specific salt form used by Hikma, if any, and whether it qualifies as "pharmaceutically acceptable" under the patent's definition, could be a focal point of the infringement analysis.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides a general definition, stating the term is "well known to the skilled artisan" (US 11,357,820, col. 3:35-36). This could support a broad interpretation covering any salt suitable for pharmaceutical use.
    • Evidence for a Narrower Interpretation: The patent explicitly mentions a "tirzepatide trifluoroacetate salt" as one embodiment (US 11,357,820, col. 3:36-37). A defendant might argue this example implicitly limits the scope to similar or commonly used salts in the peptide field, although this is generally a difficult argument to win without disclaimer.

For '820 Patent

  • The Term: "dibasic sodium phosphate"
  • Context and Importance: Practitioners may focus on this term because its precise chemical form is not specified in Claim 1. The '820 patent's specification and abstract mention "dibasic sodium phosphate" and the complaint states that Lilly's own products contain "sodium phosphate dibasic heptahydrate" (Compl. ¶17). Whether the claim term "dibasic sodium phosphate" is limited to a specific hydrate form or covers any form (e.g., anhydrous, heptahydrate) will be critical to determining infringement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: Claim 1 uses the general chemical name "dibasic sodium phosphate" without specifying a hydrate, which may suggest the claim is intended to cover all forms (US 11,357,820, claim 1). The specification also refers to "dibasic sodium phosphate" generally when describing the composition (US 11,357,820, col. 1:6-7).
    • Evidence for a Narrower Interpretation: The specification provides examples using "sodium phosphate dibasic 7H2O" (US 11,357,820, col. 4, TABLE 3). A defendant might argue that these specific examples limit the scope of the broader claim term to the heptahydrate form used in the embodiments.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement of infringement for the method patents-in-suit (e.g., '623, '987, '382, '755, '758, '740). The basis for inducement is the allegation that Hikma's proposed product labeling will instruct and encourage healthcare providers and patients to administer the generic product in a manner that directly infringes the claimed methods of treatment and dosing regimens (Compl. ¶94; Compl. ¶104; Compl. ¶123). Contributory infringement is also alleged on the basis that the proposed products are especially made for use in the patented methods and are not suitable for substantial non-infringing use (Compl. ¶97; Compl. ¶116).
  • Willful Infringement: The complaint alleges that Hikma was aware of the asserted patents at the time it submitted its ANDAs, at least because the patents are listed in the FDA's Orange Book and were included in Hikma's notice letters (Compl. ¶59; Compl. ¶76; Compl. ¶93). The complaint alleges that despite this knowledge, Hikma continues to assert its intent to engage in infringing activities. This forms the basis for the request for a finding of an exceptional case and an award of attorneys' fees (Compl. p. 51, prayer (f)).

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

  • Structural and Formulation Identity: A primary factual question will be whether Hikma's proposed generic products contain the exact tirzepatide compound claimed in the '780 patent and the specific formulation components and concentrations claimed in the '820, '756, and '404 patents. While infringement of a compound patent in an ANDA case is often straightforward, any minor deviation in the formulation could create a significant dispute over the literal scope of the formulation patent claims.
  • Induced Infringement via Labeling: For the multiple asserted method-of-use patents, a central issue for the court will be whether Hikma's proposed product label will inevitably instruct or encourage physicians and patients to perform the patented dosing regimens for treating diabetes and obesity. The analysis will focus on whether the language of the proposed label directs users to follow the specific dose-escalation and maintenance steps required by the claims.
  • Claim Construction of Excipients: The construction of chemical terms like "dibasic sodium phosphate" may be a key battleground. The case could turn on whether the general term used in the claims is limited by the specific examples in the patent specifications (e.g., the heptahydrate form), a frequent point of contention in pharmaceutical patent litigation.
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