Aveo Pharma Inc v. Hetero USA Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: AVEO Pharmaceuticals, Inc. (Delaware)
  • Defendant: Hetero USA Inc. (Delaware), HETERO LABS LIMITED UNIT-V (India), Hetero Labs Ltd (India), and Sandoz Inc. (Delaware)
  • Plaintiff's Counsel: Farnan LLP
• Case Identification: 1:25-cv-00639, D. Del., 04/24/2026
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendants Hetero USA and Sandoz are Delaware corporations, and the foreign Hetero entities may be sued in any judicial district where personal jurisdiction exists.
• Core Dispute: Plaintiff alleges that Defendants' filing of an Abbreviated New Drug Application (ANDA) for a generic version of Plaintiff's FOTIVDA® (tivozanib) product constitutes an act of infringement of a patent directed to methods of treating refractory renal cell carcinoma.
• Technical Context: The technology relates to specific dosing regimens for tivozanib, a tyrosine kinase inhibitor, used as a later-line treatment for patients with advanced or refractory renal cell carcinoma (RCC).
• Key Procedural History: This is a patent infringement action filed under the Hatch-Waxman Act, triggered by Defendants' submission of ANDA No. 220437 with a Paragraph IV certification, asserting that the patent-in-suit is invalid and/or not infringed by their proposed generic product.

Case Timeline

Date	Event
2018-11-05	'365 Patent Priority Date
2020-03-31	Plaintiff AVEO submits New Drug Application (NDA) for FOTIVDA®
2021-03-10	U.S. FDA approves FOTIVDA® NDA
2022-11-22	'365 Patent Issue Date
2025-04-22	Defendants submit ANDA for generic tivozanib (on or before this date)
2025-04-23	Plaintiff AVEO receives Paragraph IV Notice Letter from Defendants
2026-03-10	FOTIVDA® New Chemical Entity (NCE) exclusivity expires
2026-04-24	Complaint Filing Date

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

U.S. Patent No. 11,504,365 - "Use of Tivozanib to Treat Subjects with Refractory Cancer"

• Patent Identification: U.S. Patent No. 11,504,365, "Use of Tivozanib to Treat Subjects with Refractory Cancer," issued November 22, 2022.

The Invention Explained

• Problem Addressed: The patent's background section describes a need for additional therapies for patients with advanced or refractory renal cell carcinoma (RCC) for whom first and second-line treatments-including other tyrosine kinase inhibitors (TKIs) and modern checkpoint inhibitors-have failed to be effective '365 Patent, col. 2:7-12
• The Patented Solution: The invention provides a method of using tivozanib, a selective VEGF receptor TKI, as a third-line therapy for this specific "refractory" patient population '365 Patent, col. 2:16-24 The method specifies a particular dosing regimen, such as administering 1.5 mg of tivozanib daily for 21 days followed by a 7-day break, and includes instructions for dose reduction in response to certain adverse events like moderate hepatic impairment '365 Patent, col. 2:45-50 '365 Patent, col. 5:9-13 This treatment protocol is designed to achieve a specific clinical outcome, namely a progression-free survival of at least five months '365 Patent, abstract
• Technical Importance: The patented method provides a new, clinically-validated treatment protocol for a difficult-to-treat cancer patient population, leveraging tivozanib's high selectivity to potentially offer an improved efficacy and tolerability profile compared to other available therapies '365 Patent, col. 1:40-48

Key Claims at a Glance

• The complaint asserts independent claims 1 and 7 ('365 Patent, Compl. ¶58).
• Independent Claim 1 Essential Elements:
  • A method of treating a human subject with refractory advanced RCC who has previously received at least two anti-cancer therapies, including at least one TKI.
  • The method comprises administering treatment cycles "consisting essentially of" orally administering 1.5 mg of tivozanib hydrochloride daily for 21 days, followed by 7 days off.
  • This administration continues until the subject experiences moderate hepatic impairment, at which point the dose is reduced from 1.5 mg to 1.0 mg.
  • The method is performed "thereby to achieve a progression free survival in the subject of at least 5 months."
• Independent Claim 7 Essential Elements:
  • A method of treating a human subject with refractory advanced RCC who has previously received at least two anti-cancer therapies (including at least one TKI) and is currently "experiencing moderate hepatic impairment."
  • The method comprises administering treatment cycles "consisting essentially of" orally administering 1.0 mg of tivozanib hydrochloride daily for 21 days, followed by 7 days off.
  • The method is performed "thereby to treat the RCC."
• The complaint alleges infringement of "at least, by way of example, independent claims 1 and 7," which suggests the right to assert other claims is reserved Compl. ¶58

III. The Accused Instrumentality

Product Identification

• Defendants' proposed generic tivozanib hydrochloride products, as described in ANDA No. 220437 (the "Proposed ANDA Product") Compl. ¶¶1, 46 The product is intended to be a generic equivalent of AVEO's FOTIVDA® and will be offered in strengths equivalent to 1.34 mg and 0.89 mg of tivozanib base Compl. ¶46

Functionality and Market Context

• The Proposed ANDA Product is a TKI intended for the treatment of adult patients with relapsed or refractory advanced RCC who have received two or more prior systemic therapies Compl. ¶60 The complaint alleges that the product's proposed label will instruct healthcare providers on its administration, including a starting dose equivalent to 1.5 mg tivozanib hydrochloride for a 21-day on, 7-day off cycle, and a dose reduction to 1.0 mg for patients with moderate hepatic impairment Compl. ¶¶64, 66-67 The commercialization of this product is contingent on FDA approval of the ANDA Compl. ¶11 No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'365 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A method of treating a human subject with refractory advanced renal cell carcinoma (RCC) having previously received at least two anti-cancer therapies, at least one of which included a tyrosine kinase inhibitor (TKI)...	The Proposed ANDA Product's label indicates it for treating adult patients with relapsed or refractory RCC following two or more prior systemic therapies and describes a clinical study where patients had received a prior TKI.	¶60; ¶63	col. 2:29-38
...administering to the subject treatment cycles consisting essentially of: orally administering a pharmaceutical composition comprising an active agent consisting essentially of 1.5 mg tivozanib hydrochloride daily for 21 days followed by 7 days without administration of tivozanib hydrochloride...	The proposed label recommends a dosage of 1.34 mg tivozanib base (equivalent to 1.5 mg tivozanib hydrochloride) taken once daily for 21 days on treatment, followed by 7 days off treatment.	¶64	col. 2:45-50
...until the subject experiences moderate hepatic impairment, upon which the amount of tivozanib hydrochloride in each treatment cycle is reduced from 1.5 mg to 1.0 mg,	The proposed label includes instructions to reduce the dose for patients with moderate hepatic impairment, and the reduced dosage form contains 1.0 mg of tivozanib hydrochloride.	¶66; ¶67	col. 5:9-13
...thereby to achieve a progression free survival in the subject of at least 5 months.	The proposed label will report clinical trial efficacy results showing a median duration of progression-free survival of 5.6 months.	¶69	col. 23:49-51

• Identified Points of Contention:
  • Scope Questions: The claims use the transitional phrase "consisting essentially of." This raises the question of whether the administration of Defendants' product as directed by its label would include any unrecited steps (e.g., co-administration of other drugs for managing side effects) that might materially affect the basic and novel characteristics of the claimed method, thereby potentially avoiding infringement.
  • Technical Questions: A key question for the court will be whether the "thereby to achieve" clause in Claim 1 is an active limitation requiring proof of the outcome in a patient, or a statement of intended result. The infringement allegation relies on the proposed label reporting a median statistical outcome from a clinical trial Compl. ¶69, which raises the legal question of whether this is sufficient to prove inducement of a method that "achieve[s]" a specific outcome in "the subject."

V. Key Claim Terms for Construction

• The Term: "consisting essentially of"
  • Context and Importance: This transitional phrase defines the scope of the claimed method, falling between the open-ended "comprising" and the closed "consisting of." Its construction is critical to determining whether the labeled use of the accused product, which may involve concomitant medications or monitoring steps not explicitly recited, falls within the claim's boundaries.
  • Intrinsic Evidence for a Broader Interpretation: The patent's general purpose is to provide an effective treatment. A party could argue the phrase only excludes additional steps that would interfere with the fundamental activity of tivozanib in achieving the claimed progression-free survival.
  • Intrinsic Evidence for a Narrower Interpretation: The patent's support is heavily based on the TIVO-3 clinical trial, which evaluated tivozanib as a monotherapy against sorafenib monotherapy '365 Patent, col. 21:1-8 A party may argue that "consisting essentially of" is intended to limit the method to tivozanib monotherapy, as that is the only context in which the claimed efficacy was demonstrated in the patent.
• The Term: "thereby to achieve a progression free survival in the subject of at least 5 months"
  • Context and Importance: Practitioners may focus on this term because its interpretation-as either an essential method limitation or a mere statement of intended result-is dispositive for infringement. If it is a limitation, the plaintiff must show that the induced method actually achieves this outcome, a potentially high evidentiary bar for a method-of-treatment claim.
  • Intrinsic Evidence for Interpretation (as a limitation): The specification, particularly the summary of the TIVO-3 trial results and associated figures, emphasizes the 5.59-month median PFS as the key inventive discovery distinguishing tivozanib from the prior art comparator '365 Patent, FIG. 1 '365 Patent, col. 23:49-51 This suggests the outcome is a core, defining feature of the invention.
  • Intrinsic Evidence for Interpretation (as intended result): The term "achieve" in "the subject" (singular) could be contrasted with the statistical, population-based nature of "progression free survival." A party could argue that since this outcome is not guaranteed in every individual patient, the clause should be read as describing the purpose or advantage of the method, not a strict limitation that must be met in every instance of infringement.

VI. Other Allegations

• Indirect Infringement: The complaint is founded on a theory of induced infringement. It alleges that Defendants, with knowledge of the '365 Patent, will cause infringement by physicians and patients through the instructions on the Proposed ANDA Product's label, which allegedly direct users to perform all steps of the claimed methods Compl. ¶¶57, 71, 73
• Willful Infringement: The complaint alleges willful infringement based on Defendants' knowledge of the '365 Patent, as demonstrated by their Paragraph IV certification, and their subsequent and continued actions to seek FDA approval and market the infringing product Compl. ¶¶72, 78

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

• A core issue will be one of claim construction and infringement: Can the act of prescribing a drug, guided by a label reporting a median progression-free survival of 5.6 months in a clinical trial, satisfy the claim limitation requiring the method to "thereby to achieve a progression free survival in the subject of at least 5 months" for the purpose of finding induced infringement?
• A second key question will center on the scope of the claimed method: Does the transitional phrase "consisting essentially of" limit the method to tivozanib monotherapy, as tested in the patent's supporting clinical trial, or can it be construed more broadly to encompass use with concomitant medications that may be administered in real-world clinical practice?
• A third determinative issue will be a question of fact and law regarding the patient population: Does the label for the Proposed ANDA Product direct its use in a patient population that meets the claim requirement of having received "at least two anti-cancer therapies, at least one of which included a tyrosine kinase inhibitor," and for Claim 7, also "experiencing moderate hepatic impairment"?