DCT

1:25-cv-01520

ViiV Healthcare Co v. Zydus Pharma USA Inc

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-01520, D. Del., 12/17/2025
  • Venue Allegations: Plaintiffs allege venue is proper because Defendants conduct substantial business in Delaware, including marketing and selling generic pharmaceutical products to residents of the state, and have previously availed themselves of the jurisdiction of the court.
  • Core Dispute: Plaintiffs allege that Defendants' filing of an Abbreviated New Drug Application (ANDA) to market a generic version of the HIV-1 treatment JULUCA® constitutes an act of patent infringement.
  • Technical Context: The case involves antiretroviral combination therapy for Human Immunodeficiency Virus (HIV), a field where fixed-dose combination tablets are a standard of care to improve patient adherence and treatment outcomes.
  • Key Procedural History: The litigation was triggered by Defendants' submission of ANDA No. 220907 to the U.S. Food and Drug Administration (FDA) and their subsequent Notice Letter, dated November 3, 2025, which included a Paragraph IV Certification asserting that the patents-in-suit are invalid, unenforceable, and/or will not be infringed.

Case Timeline

Date Event
2008-12-11 U.S. Patent No. 9,242,986 Priority Date
2010-01-27 U.S. Patent No. 10,426,780 Priority Date
2016-01-26 U.S. Patent No. 9,242,986 Issued
2019-10-01 U.S. Patent No. 10,426,780 Issued
2025-11-03 Defendants' ANDA Notice Letter Date
2025-12-17 Complaint Filing Date

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

U.S. Patent No. 9,242,986 - "Synthesis of carbamoylpyridone HIV integrase inhibitors and intermediates"

The Invention Explained

  • Problem Addressed: The patent's background describes known processes for synthesizing certain HIV integrase inhibitors, noting that these processes can be complex and may introduce key chemical structures late in the synthesis sequence (’986 Patent, col. 1:14-34).
  • The Patented Solution: The invention provides modified synthesis processes that utilize an "early bromination step" to create a leaving group on a pyridone ring, which facilitates the later attachment of an amide side chain (’986 Patent, col. 1:43-48). The patent also claims specific crystalline forms of the final compound, dolutegravir sodium, which result from such processes.
  • Technical Importance: Developing efficient synthesis methods and stable, reproducible crystalline forms (polymorphs) of an active pharmaceutical ingredient is critical for reliable, large-scale manufacturing and consistent drug performance.

Key Claims at a Glance

  • The complaint alleges infringement of "one or more claims" and specifically references claims 1-12 in its allegation of an unjustified Paragraph IV certification (Compl. ¶36, ¶44). Independent claims in this range include Claims 1 and 7.
  • Claim 1 recites:
    • A crystal form of a sodium salt of a compound of formula AA
    • having characteristic diffraction peaks at 6.4°±0.2°, 9.2°±0.2°, 13.8°±0.2°, 19.2°±0.2° and 21.8°±0.2° degrees two-theta in an X-ray powder diffraction pattern.
  • The complaint reserves the right to assert additional claims (Compl. ¶36).

U.S. Patent No. 10,426,780 - "Antiviral therapy"

The Invention Explained

  • Problem Addressed: The patent background explains that while combination therapies are beneficial in treating HIV, not all drug combinations are feasible due to factors like chemical instability, the potential for antagonistic effects, or difficulties in creating a suitable co-formulation (’780 Patent, col. 2:4-18).
  • The Patented Solution: The invention claims combinations of specific therapeutic agents for treating HIV (’780 Patent, Abstract). The core of the invention is the combination of the HIV integrase inhibitor dolutegravir (identified as a compound of formula I) with another antiretroviral agent, rilpivirine, to inhibit HIV replication.
  • Technical Importance: Fixed-dose combination therapies that combine multiple antiretroviral drugs into a single tablet are a cornerstone of modern HIV treatment, enhancing patient adherence and simplifying treatment regimens.

Key Claims at a Glance

  • The complaint alleges infringement of "one or more claims" and notes that Defendants' notice letter does not dispute infringement of Claims 1-11, 13, and 15-17, instead challenging their validity (Compl. ¶46, ¶52). Independent Claim 1 is asserted.
  • Claim 1 recites:
    • A combination comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof,
    • and rilpivirine, or a pharmaceutically acceptable salt thereof.
  • The complaint reserves the right to assert additional claims (Compl. ¶46).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendants' "Proposed ANDA Product" associated with ANDA No. 220907 (Compl. ¶12).

Functionality and Market Context

The Proposed ANDA Product is a generic version of Plaintiffs' JULUCA® tablets, formulated to contain 50 mg of dolutegravir and 25 mg of rilpivirine (Compl. ¶12). It is intended for use as a complete regimen for the treatment of HIV-1 infection in certain adults who are virologically suppressed (Compl. ¶12, ¶26). The complaint alleges that the ANDA contains data demonstrating the bioequivalence of the proposed generic product to JULUCA® (Compl. ¶33).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

9,242,986 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A crystal form of a sodium salt of a compound of formula AA... The complaint alleges that "dolutegravir sodium as covered in one or more of the claims of the '986... Patent[] is and/or will be present in the Proposed ANDA Product." ¶32 col. 39:6-8
...having characteristic diffraction peaks at 6.4°±0.2°, 9.2°±0.2°, 13.8°±0.2°, 19.2°±0.2° and 21.8°±0.2° degrees two-theta in an X-ray powder diffraction pattern. The complaint alleges that the Proposed ANDA Product infringes one or more claims of the patent, which requires the presence of the specific claimed crystal form. ¶36 col. 39:15-21
  • Identified Points of Contention:
    • Factual/Evidentiary Question: A primary point of contention for the ’986 Patent may be factual. Does the manufacturing process detailed in Zydus's ANDA produce the specific crystalline form (polymorph) of dolutegravir sodium defined by the diffraction peaks in Claim 1? Zydus may argue its product contains a different, non-infringing crystalline form. The complaint does not provide the technical evidence to resolve this question.

10,426,780 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A combination comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, ... The Proposed ANDA Product is a tablet containing 50 mg of dolutegravir sodium, which is a salt of the compound of formula (I). ¶12, ¶32 col. 3:31-40
...and rilpivirine, or a pharmaceutically acceptable salt thereof. The Proposed ANDA Product is a tablet containing 25 mg of rilpivirine. ¶12 col. 13:24-25
  • Identified Points of Contention:
    • Legal Question (Validity): The complaint alleges that for many asserted claims of the ’780 Patent, Defendants' Paragraph IV certification focuses on invalidity rather than non-infringement (Compl. ¶52). This suggests the central dispute may not be whether the accused product meets the claim limitations, but whether the patent is valid in the first place (e.g., whether combining two known antiretroviral agents was obvious to a person of ordinary skill).

V. Key Claim Terms for Construction

  • The Term: "combination" (’780 Patent, Claim 1)
  • Context and Importance: The definition of "combination" is central to the scope of Claim 1 of the '780 Patent. The dispute will turn on whether the term merely requires the co-presence of the two active ingredients in a single dosage form, or if it carries additional functional or formulation requirements.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discusses "Combinations administered in a single dosage unit" which may support an interpretation that any co-formulated tablet containing the two specified drugs meets the limitation (’780 Patent, col. 2:7-8).
    • Evidence for a Narrower Interpretation: The background section discusses the challenges of creating feasible combinations, referencing factors like "chemical instability," "potential for antagonistic or merely additive activities," and "achieving a suitable formulation" (’780 Patent, col. 2:13-18). A party could argue this context imbues the term "combination" with implicit requirements beyond mere co-presence.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges Defendants will induce infringement of both patents. The basis for this allegation is that the label for the Proposed ANDA Product will "substantially copy the instructions for JULUCA®," thereby instructing and encouraging physicians and patients to use the product in an infringing manner (Compl. ¶34, ¶40, ¶50).
  • Willful Infringement: The complaint does not use the term "willful," but it lays the groundwork for such a claim by alleging that Defendants had pre-suit knowledge of the patents at the time they filed their ANDA (Compl. ¶42, ¶53). It further alleges that Defendants' Paragraph IV certifications were "wholly unjustified" and lacked a "good faith basis," and seeks a declaration that the case is "exceptional" under 35 U.S.C. § 285, which allows for the recovery of attorneys' fees (Compl. ¶44, ¶55; Prayer for Relief ¶f).

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

  • A core issue for the '986 patent will be one of evidentiary proof: does the product defined in Defendants' confidential ANDA filing contain the specific crystalline polymorph of dolutegravir sodium required by the patent's claims, or will Defendants be able to demonstrate that their product is made with a different, non-infringing form?
  • For the '780 patent, a central question will likely be one of patent validity: given that both dolutegravir and rilpivirine were known antiretroviral agents, was it obvious to a person of ordinary skill in the art to combine them into a fixed-dose tablet for the treatment of HIV-1, or did the claimed combination represent a non-obvious advance over the prior art?