DCT

1:26-cv-00814

Exelixis Inc v. Intas Pharma Ltd

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I. Executive Summary and Procedural Information

Parties & Counsel

Case Identification

1:26-cv-00814, D. Del., 07/06/2026

Venue Allegations

Venue is based on Plaintiff being a Delaware corporation and Defendants having previously availed themselves of the forum by filing claims and counterclaims in other actions in the district. For Intas, a foreign corporation, venue is alleged to be proper in any judicial district.

Core Dispute

Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to the FDA for a generic version of the cancer drug CABOMETYX® constitutes an act of infringement of five U.S. patents covering the drug's active ingredient, cabozantinib.

Technical Context

The technology involves specific salt forms (malate) and crystalline polymorphs of cabozantinib, a small-molecule tyrosine kinase inhibitor, which are crucial for the drug's stability, manufacturability, and therapeutic efficacy in treating various cancers.

Key Procedural History

This is a Hatch-Waxman action initiated in response to Defendants' Paragraph IV certification asserting that the Asserted Patents are "not infringed" and/or "invalid and/or unenforceable." The complaint was filed within the 45-day window following receipt of the Defendants' notice letter, triggering a 30-month stay of FDA approval for the generic product.

Case Timeline

Date Event
2009-01-16 Priority Date for '776, '439, '440, and '015 Patents
2011-02-10 Priority Date for '039 Patent
2014-11-04 U.S. Patent No. 8,877,776 Issues
2016-01-01 CABOMETYX® New Drug Application Approved by FDA (Year only)
2021-08-17 U.S. Patent No. 11,091,439 Issues
2021-08-17 U.S. Patent No. 11,091,440 Issues
2021-08-24 U.S. Patent No. 11,098,015 Issues
2024-10-29 U.S. Patent No. 12,128,039 Issues
2026-05-22 Defendants' Notice Letter Dated
2026-05-26 Plaintiff Receives Notice Letter
2026-06-18 Accord Confirms Dosage Strengths of ANDA Product via Email
2026-07-06 Complaint Filed

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

U.S. Patent No. 8,877,776 - "(L)-malate salt of N-(4-{[6,7-bis(methyloxy) quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide," issued November 4, 2014.

The Invention Explained

  • Problem Addressed: While the base compound cabozantinib was known to inhibit protein kinases for cancer treatment, the patent addresses the need to find a form of the drug with suitable physicochemical properties (e.g., stability, processability, manufacturability) for development into a pharmaceutical product Compl. ¶1 '776 Patent, col. 3:17-26
  • The Patented Solution: The patent discloses the (L)-malate salt of cabozantinib and identifies a specific crystalline polymorph, "Form N-2," which is claimed to have a preferred combination of properties for pharmaceutical development, such as thermal stability and low hygroscopicity '776 Patent, abstract '776 Patent, col. 7:1-9 The patent provides characterization data, such as the X-ray powder diffraction (XRPD) pattern in Figure 8, to uniquely identify this crystalline form '776 Patent, FIG. 8
  • Technical Importance: Identifying and securing a specific, stable crystalline form (polymorph) of an active pharmaceutical ingredient is a critical step in drug development, as it ensures consistent manufacturing, shelf life, and bioavailability.

Key Claims at a Glance

  • The complaint asserts claims 1, 2, and 3 Compl. ¶33
  • Independent Claim 1 is broken down as follows:
    • An N-(4-{[6,7-bis(methyloxy)quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide (L)-malate salt,
    • wherein said salt is in crystalline Form N-2,
    • and said Form N-2 is characterized by at least one of the following: (i) a specific solid state 13C NMR spectrum, (ii) a specific powder x-ray diffraction (PXRD) pattern, or (iii) an XRPD pattern substantially in accordance with the pattern shown in FIG. 8 Compl. ¶34

U.S. Patent No. 11,091,439 - "Malate salt of N-(4-{[6,7-bis(methyloxy) quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide, and crystalline forms therof for the treatment of cancer," issued August 17, 2021.

The Invention Explained

  • Problem Addressed: The patent background describes the role of protein kinases in diseases like cancer and notes that modulating their activity is a valuable therapeutic strategy '439 Patent, col. 1:58-2:2 The implicit problem is the need for a stable, administrable form of the cabozantinib molecule to achieve this modulation.
  • The Patented Solution: The invention provides malate salts of cabozantinib-including the (L)-malate, (D)-malate, and racemic (DL)-malate salt forms-as well as crystalline and amorphous forms thereof '439 Patent, abstract By creating these salt forms, the invention provides concrete chemical entities with physical properties that can be optimized for pharmaceutical use '439 Patent, col. 3:17-26
  • Technical Importance: Creating different salt forms of a drug is a standard but vital part of pharmaceutical development to find a version with optimal solubility, stability, and manufacturability.

Key Claims at a Glance

  • The complaint asserts claims 1, 3, and 4 Compl. ¶43
  • Independent Claim 1 is broken down as follows:
    • N-(4-{[6,7-bis(methyloxy)quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide, malate salt,
    • wherein said salt is crystalline Compl. ¶44

U.S. Patent No. 11,091,440 - "Malate salt of N-(4-{[6,7-bis(methyloxy) quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide, and crystalline forms thereof for the treatment of cancer," issued August 17, 2021 ([Compl. ¶20](https://ex:cit:13)).

  • Technology Synopsis: This patent addresses the formulation of the drug product by claiming a pharmaceutical composition that comprises the crystalline malate salt of cabozantinib combined with a "pharmaceutically acceptable excipient" '440 Patent, abstract This moves beyond the active ingredient itself to its combination with inactive ingredients necessary for creating a final dosage form like a tablet.
  • Asserted Claims: Claims 1 and 3 Compl. ¶53
  • Accused Features: The Accord ANDA Product is alleged to be a pharmaceutical composition containing crystalline cabozantinib malate and a pharmaceutically acceptable excipient, thereby infringing the '440 Patent Compl. ¶55

U.S. Patent No. 11,098,015 - "Malate salt of N-(4-{[6,7-bis(methyloxy) quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide, and crystalline forms thereof for the treatment of cancer," issued August 24, 2021 ([Compl. ¶21](https://ex:cit:17)).

  • Technology Synopsis: This patent protects the therapeutic use of the invention by claiming a method of treating cancer. The claimed method comprises administering a crystalline malate salt (specifically the (L)-malate or (D)-malate salt) of cabozantinib to a subject in need thereof '015 Patent, abstract
  • Asserted Claims: Claims 1, 2, and 3 Compl. ¶63
  • Accused Features: The Accord ANDA Product is intended for the treatment of cancer, and its future marketing and sale for this use is alleged to infringe the claimed method Compl. ¶65 Compl. ¶67

U.S. Patent No. 12,128,039 - "Processes for Preparing Quinoline Compounds and Pharmaceutical Compositions Containing Such Compounds," issued October 29, 2024 ([Compl. ¶22](https://ex:cit:22)).

  • Technology Synopsis: This patent addresses the purity of the final drug product. It claims a pharmaceutical composition for oral administration that contains cabozantinib (L)-malate (identified as Compound IB) but has "100 ppm or less" of a specific impurity, 6,7-dimethoxy-quinoline-4-ol '039 Patent, abstract This negative limitation sets a purity standard for the composition.
  • Asserted Claims: Claims 1-11, 13-14, 16-17, 19-20, and 22 Compl. ¶73
  • Accused Features: The complaint alleges that the Accord ANDA Product is a pharmaceutical composition that contains cabozantinib (L)-malate and meets the purity requirement of having 100 ppm or less of the specified impurity Compl. ¶75 The complaint includes a visual depicting the chemical structure of "Compound IB," which is cabozantinib (L)-malate Compl. ¶74

III. The Accused Instrumentality

  • Product Identification: The accused instrumentality is the "Accord ANDA Product," for which Defendants submitted Abbreviated New Drug Application (ANDA) No. 221568 to the FDA Compl. ¶1 It is a generic version of CABOMETYX® (cabozantinib (S)-Malate Tablets) in 20 mg, 40 mg, and 60 mg dosage strengths Compl. ¶26
  • Functionality and Market Context: The product is a generic oral tyrosine kinase inhibitor intended for treating various cancers, including kidney, liver, and thyroid cancers Compl. ¶24 By filing an ANDA, Defendants have represented to the FDA that their product has the same active ingredient, dosage form, strength, and is bioequivalent to Plaintiff's CABOMETYX® product Compl. ¶27 The filing is an attempt to enter the market with a generic competitor prior to the expiration of Plaintiff's patents Compl. ¶1

IV. Analysis of Infringement Allegations

8,877,776 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
N-(4-{[6,7-bis(methyloxy)quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide (L)-malate salt... N-(4-{[6,7-bis(methyloxy)quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide is the chemical nomenclature for cabozantinib, and the Notice Letter states the active ingredient is cabozantinib Compl. ¶35 ¶35 col. 3:35-46
...wherein said salt is in crystalline Form N-2... Plaintiff alleges that materials from the ANDA "support the conclusion that the claimed crystalline cabozantinib (L)-malate Form N-2 may be present" and are "insufficient to demonstrate that the claimed ... Form N-2 is not present." ¶35 col. 9:1-2
...and said Form N-2 is characterized by at least one of the following: (i) a solid state 13C NMR spectrum... (ii) a powder x-ray diffraction pattern... and/or (iii) an x-ray powder diffraction (XRPD) pattern substantially in accordance with the pattern shown in FIG. 8. The complaint alleges infringement based on a review of confidential ANDA materials, but does not specify which of the three characterization methods is met by the accused product Compl. ¶35 ¶34; ¶35 col. 8:33-47

11,091,439 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
N-(4-{[6,7-bis(methyloxy)quinolin-4-yl]oxy}phenyl)-N'-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide, malate salt... The active ingredient in the Accord ANDA Product is identified as cabozantinib, which is the chemical nomenclature for the claimed compound Compl. ¶45 ¶45 col. 5:27-39
...wherein said salt is crystalline. Based on a review of confidential ANDA materials, Plaintiff alleges that the Accord ANDA Product "contains crystalline cabozantinib malate" Compl. ¶45 ¶45 col. 7:26-31
  • Identified Points of Contention:
    • Evidentiary Questions: For the '776 patent, a primary point of contention will be factual and evidentiary: does the Accord ANDA Product contain the specific polymorph "crystalline Form N-2"? The complaint's tentative language ("may be present" and "insufficient to demonstrate that [it] is not present") suggests that this is a key dispute for which definitive evidence may be contested Compl. ¶35
    • Scope Questions: For the '439 patent and others claiming a "crystalline" salt more broadly, a potential dispute may arise over the definition of "crystalline." The question will be whether the degree of crystallinity in the accused product is sufficient to meet the claim limitation, particularly if the product is a mixture of crystalline and amorphous forms.

V. Key Claim Terms for Construction

  • The Term: "crystalline Form N-2" (from '776 Patent)

  • Context and Importance: This term is the central limitation of the '776 patent. The outcome of the infringement analysis for this patent will depend entirely on whether the defendants' product is found to be this specific polymorph. Practitioners may focus on this term because polymorphic identity is a common and often case-dispositive issue in pharmaceutical patent litigation.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The claim language allows for characterization by "at least one of" three different analytical methods (NMR, PXRD, or an XRPD pattern match) Compl. ¶34 A party may argue that meeting the criteria for just one of these methods is sufficient for infringement, even if the product does not perfectly match all characteristics.
    • Evidence for a Narrower Interpretation: The patent provides very specific peak values for the NMR and PXRD spectra and a reference pattern in FIG. 8 '776 Patent, claim 1 '776 Patent, FIG. 8 A party may argue that these define a very specific structure and that any significant deviation in the accused product's analytical data places it outside the claim's scope. The patent also provides a specific method for preparing Form N-2, which could be used to argue for a narrower construction limited to the product of that process '776 Patent, Example 4

  • The Term: "crystalline" (from '439, '440, and '015 Patents)

  • Context and Importance: This term appears in the independent claims of three asserted patents. Its construction is critical because if the defendants' product is found not to be "crystalline," it may avoid infringement of all three patents.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: A party could argue the term should be given its plain and ordinary meaning, which requires only some degree of long-range molecular order. The patents disclose both "crystalline and amorphous forms," suggesting the inventors viewed them as distinct categories, and anything not "amorphous" would be "crystalline" '439 Patent, abstract
    • Evidence for a Narrower Interpretation: The patents repeatedly discuss specific crystalline forms, namely N-1 and N-2, as the preferred embodiments of the invention '439 Patent, col. 7:26-8:40 A party could argue that "crystalline" should be interpreted in light of these specific examples and limited to substantially pure polymorphic forms, rather than covering materials with only a low degree of crystallinity.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement of infringement, stating that upon approval, Defendants will commercialize the Accord ANDA Product and its active ingredient, thereby inducing others (e.g., patients and doctors) to use the product in an infringing manner Compl. ¶37 Compl. ¶47 Compl. ¶57 Compl. ¶67 Compl. ¶77
  • Willful Infringement: The complaint alleges that Defendants acted "without a reasonable basis for believing that they would not be liable for directly and/or indirectly infringing" the Asserted Patents, and describes the case as "exceptional" Compl. ¶40 Compl. ¶50 Compl. ¶60 Compl. ¶70 Compl. ¶80 This allegation is based on Defendants having knowledge of the patents at least as of the time they submitted their Paragraph IV certification Compl. ¶29

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

  • A core issue will be one of polymorphic identity: Does the Accord ANDA Product contain the specific "crystalline Form N-2" as defined in the '776 patent? The case will likely involve a significant battle of expert testimony and competing analytical data (e.g., PXRD, NMR) to prove or disprove the presence of this exact crystal structure.
  • A second key issue will be one of definitional scope: For the patents claiming a "crystalline" salt without specifying a form, how will the court construe this term? The central question is whether any detectable degree of crystallinity is sufficient to infringe, or if the term will be narrowed to require a substantially pure polymorphic form, as exemplified by Forms N-1 and N-2 in the specification.
  • A final factual question will relate to the purity limitation of the '039 patent: Can Exelixis prove that Accord's manufacturing process consistently produces a final drug product containing "100 ppm or less" of the specified 6,7-dimethoxy-quinoline-4-ol impurity, or will Accord be able to show that at least some batches fall outside this claimed purity level?
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