DCT

1:24-cv-00907

ViiV Healthcare Co v. Hetero USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-00907, D. Del., 08/02/2024
  • Venue Allegations: Venue is asserted based on Defendant Hetero USA Inc. being incorporated in Delaware, and on allegations that all defendants conduct substantial business in the state, including the marketing and sale of generic pharmaceutical products.
  • Core Dispute: Plaintiffs allege that Defendants’ filing of an Abbreviated New Drug Application (ANDA) for a generic version of the HIV treatment DOVATO® constitutes an act of infringement of two patents related to a specific crystalline form of the active ingredient dolutegravir sodium and its use in a combination therapy.
  • Technical Context: The technology concerns antiretroviral therapies for Human Immunodeficiency Virus (HIV), specifically a two-drug, fixed-dose combination tablet that represents a simplified treatment regimen in a major therapeutic market.
  • Key Procedural History: The action was initiated under the Hatch-Waxman Act following a notice letter dated June 20, 2024, in which Defendants notified Plaintiffs of their filing of ANDA No. 216543 with a Paragraph IV certification. This certification asserts that the patents-in-suit are invalid, unenforceable, or will not be infringed by the proposed generic product. The complaint notes that one of the patents-in-suit, the '986 Patent, has received pediatric exclusivity, extending its statutory protection.

Case Timeline

Date Event
2008-12-11 '986 Patent Priority Date
2010-01-27 '985 Patent Priority Date
2016-01-26 '986 Patent Issue Date
2022-02-01 '985 Patent Issue Date
2024-06-20 Defendants’ Paragraph IV Notice Letter
2024-08-02 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," Issued January 26, 2016

The Invention Explained

  • Problem Addressed: The patent describes a need for modified or improved processes for synthesizing a class of compounds having HIV integrase inhibitory activity (’986 Patent, col. 1:8-11). The background suggests that prior art synthetic routes could be inefficient, for example by attaching a key sidechain late in the process after the formation of a complex core structure (’986 Patent, col. 1:13-34).
  • The Patented Solution: The invention discloses a synthetic process that utilizes an "early bromination step" to provide a leaving group for the subsequent attachment of an amide side chain (’986 Patent, col. 1:43-47). This approach allows the sidechain to be added before the final tricyclic ring system of the inhibitor is formed, creating an alternative and potentially more efficient manufacturing pathway for the final compound, dolutegravir (’986 Patent, Abstract). The patent further claims specific crystalline forms of the final sodium salt product derived from this process (’986 Patent, col. 9:43-10:11).
  • Technical Importance: This patent claims specific, stable crystalline forms (polymorphs) of a significant active pharmaceutical ingredient, dolutegravir sodium, which is critical for ensuring consistency, stability, and bioavailability in a commercial drug product (Compl. ¶31).

Key Claims at a Glance

  • The complaint alleges infringement of one or more claims, and specifically notes that Defendants do not dispute infringement of Claims 1-6, 8-9, and 11, subject to their invalidity defense (Compl. ¶35, 41). Independent claim 1 is representative.
  • Independent Claim 1:
    • 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 alleges infringement of one or more claims, implying the right to assert additional claims, including dependent claims (Compl. ¶35).

U.S. Patent No. 11,234,985, "Antiviral Therapy," Issued February 1, 2022

The Invention Explained

  • Problem Addressed: The patent addresses the use of combination therapies to treat HIV infection. It notes that while combining drugs can offer benefits like increased efficacy and delayed resistance, "not all compounds are suitable for administration in combinations" due to potential issues like chemical instability, antagonistic drug interactions, or formulation difficulties (’985 Patent, col. 2:6-21).
  • The Patented Solution: The invention is directed to specific combinations of antiviral agents. The core of the patented solution is the combination of the HIV integrase inhibitor dolutegravir (identified as a compound of formula (I)) with the nucleoside reverse transcriptase inhibitor lamivudine (’985 Patent, Abstract; col. 13:58-14:2). The patent presents this specific pairing as a useful therapeutic combination for treating HIV.
  • Technical Importance: The patent covers a two-drug regimen for HIV treatment, which can reduce patient pill burden and may offer a different long-term safety profile compared to traditional three- or four-drug therapies (Compl. ¶25).

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims, highlighting that Defendants do not dispute infringement of Claims 1-7, 9, 11-14, and 16, subject to an invalidity defense (Compl. ¶46, 52). Independent claim 5 is representative of the asserted composition claims.
  • Independent Claim 5:
    • A pharmaceutical composition
    • consisting essentially of a compound of formula (I) [dolutegravir] or a pharmaceutically acceptable salt thereof,
    • and lamivudine, or a pharmaceutically acceptable salt thereof.
  • The complaint’s reference to "one or more claims" suggests the reservation of rights to assert additional claims (Compl. ¶46).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentality is Defendants’ "Proposed ANDA Product," identified as ANDA No. 216543 for "Dolutegravir Sodium; Lamivudine Tablets; Oral, Eq. 50 mg Base; 300 mg" (Compl. ¶9, 11).
  • Functionality and Market Context: The product is a proposed generic, oral, fixed-dose combination tablet containing dolutegravir sodium and lamivudine (Compl. ¶11). It is intended to be a generic equivalent of Plaintiffs' brand-name drug, DOVATO®, and is indicated for the treatment of HIV-1 infection (Compl. ¶11, 25). The complaint alleges that the proposed product is bioequivalent to DOVATO® and will be marketed with substantially similar instructions for use upon receiving FDA approval (Compl. ¶32, 33). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'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 Proposed ANDA Product is alleged to contain dolutegravir sodium, the sodium salt of the compound of formula AA. ¶31, 35 col. 9:43-10:11
...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 dolutegravir sodium in the Proposed ANDA Product will possess the claimed crystalline structure, as defined by these X-ray powder diffraction peaks. It further states Defendants do not dispute infringement of this claim, subject to their invalidity defense. ¶35, 41 col. 10:1-11
  • Identified Points of Contention:
    • Validity Question: The complaint states that in their notice letter, "Defendants do not dispute that the Proposed ANDA Product will infringe" claim 1, but instead plan to argue the claim is invalid (Compl. ¶41). Therefore, the central dispute for this patent will likely concern the validity of the claims, specifically whether the claimed crystalline form was obvious or anticipated by the prior art.

'985 Patent Infringement Allegations

Claim Element (from Independent Claim 5) Alleged Infringing Functionality Complaint Citation Patent Citation
A pharmaceutical composition... The Proposed ANDA Product is a pharmaceutical composition formulated as a tablet for oral use. ¶11, 46 col. 14:49-53
...consisting essentially of a compound of formula (I) or a pharmaceutically acceptable salt thereof,... The Proposed ANDA Product contains 50 mg of dolutegravir (equivalent to 52.6 mg dolutegravir sodium), which is a salt of the compound of formula (I). ¶11, 26, 31 col. 14:49-53
...and lamivudine, or a pharmaceutically acceptable salt thereof. The Proposed ANDA Product contains 300 mg of lamivudine. ¶11, 26 col. 14:49-53
  • Identified Points of Contention:
    • Validity Question: As with the ’986 patent, the complaint alleges that Defendants' primary defense is invalidity, not non-infringement (Compl. ¶52). A key question for the court will be whether the combination of dolutegravir and lamivudine was obvious to a person of ordinary skill in the art at the time of the invention.
    • Scope Question: The claim term "consisting essentially of" may become a point of contention. The analysis will question whether the various inactive ingredients (excipients) required for a tablet formulation materially alter the basic and novel characteristics of the claimed two-drug antiviral combination.

V. Key Claim Terms for Construction

Term from the '985 Patent: "consisting essentially of"

  • The Term: "consisting essentially of"
  • Context and Importance: This transitional phrase appears in independent claim 5 of the ’985 patent and defines the scope of the claimed pharmaceutical composition. Its construction is critical because it dictates whether additional, unlisted substances in Defendants' generic product would place it outside the claim's scope. Practitioners may focus on this term because while the accused product contains the two specified active ingredients, it necessarily includes other inactive excipients, and the effect of these on the claimed invention could be disputed.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discloses that the active compounds may be formulated with a "pharmaceutically acceptable carrier or adjuvant," and provides extensive examples of such inactive ingredients, including binders, lubricants, and diluents (’985 Patent, col. 8:62-65; col. 11:5-29). This language may support an interpretation where the presence of conventional, inactive excipients does not remove a product from the claim's scope.
    • Evidence for a Narrower Interpretation: The patent's background emphasizes that "not all compounds are suitable for administration in combinations" (’985 Patent, col. 2:14-15). A party could argue that the choice of "consisting essentially of" over the more open-ended "comprising" was a deliberate effort to limit the invention to a composition whose essential antiviral character derives only from dolutegravir and lamivudine, without material alteration from other components.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement under 35 U.S.C. § 271(b). The factual basis is that Defendants’ proposed product labeling will "substantially copy the instructions for DOVATO®" and will therefore actively instruct and encourage physicians and patients to use the generic product in a manner that infringes the asserted method claims (Compl. ¶33, 48-50).
  • Willful Infringement: The complaint alleges that the case is "exceptional" under 35 U.S.C. § 285, which is a predicate for an award of attorneys' fees (Compl. ¶44, 55). The basis for this allegation is that Defendants had knowledge of the patents-in-suit when filing their ANDA and "lacked a good faith basis" for their assertions of invalidity and non-infringement in their Paragraph IV certification (Compl. ¶44, 55).

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

  • A central question for the court will be one of validity based on obviousness: For the ’985 patent, was it obvious to a person of ordinary skill in the art at the relevant time to select and combine dolutegravir and lamivudine into a two-drug antiretroviral therapy, to the exclusion of other agents, and expect a successful outcome?
  • The litigation will also turn on a question of the patentability of a specific polymorph: For the ’986 patent, does the claimed crystalline form of dolutegravir sodium represent a non-obvious invention, or was its discovery an anticipated or routine step in the ordinary course of pharmaceutical development for a known active compound?
  • A threshold issue will involve the effect of Defendants’ pre-litigation statements: The complaint alleges that Defendants' Paragraph IV notice letter concedes infringement of numerous claims. The court will have to determine how these statements frame the dispute and to what extent they narrow the case to the primary defense of invalidity.