DCT

1:26-cv-00756

Gilead Sciences Inc v. Cipla Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:26-cv-00756, D. Del., 07/14/2026
  • Venue Allegations: Venue is alleged to be proper because the defendant, Cipla, is a foreign corporation subject to personal jurisdiction in the District of Delaware.
  • Core Dispute: Plaintiff alleges that Defendant's proposed generic HIV drug, submitted to the FDA via a 505(b)(2) application, will infringe four patents covering pharmaceutical formulations of tenofovir alafenamide (TAF) and emtricitabine (FTC), the active ingredients in Plaintiff's branded drug DESCOVY®.
  • Technical Context: The technology concerns stable, low-weight, solid oral tablet formulations for HIV treatment and prevention, a market where patient convenience and long-term safety are significant clinical considerations.
  • Key Procedural History: The complaint notes that the parties were previously involved in separate litigation over different patents related to TAF, which settled in 2022. This new action concerns patents issued in 2026 and relates to Cipla's 505(b)(2) application, which references Gilead's DESCOVY®, rather than a generic ANDA. Three of the four patents-in-suit are listed in the FDA's Orange Book for DESCOVY®.

Case Timeline

Date Event
2015-06-30 Earliest Priority Date for all Patents-in-Suit
2016-01-01 DESCOVY® approved by FDA for HIV-1 treatment (approx. date)
2019-01-01 DESCOVY® approved by FDA for HIV-1 PrEP (approx. date)
2022-01-01 TAF ANDA Settlement Agreement between parties (approx. date)
2025-12-29 Cipla sends Notice Letter to Gilead regarding 505(b)(2) Application
2026-05-19 U.S. Patent No. 12,629,338 ('338 Patent) issues
2026-06-09 U.S. Patent No. 12,648,911 ('911 Patent) issues
2026-06-23 U.S. Patent No. 12,661,323 ('323 Patent) issues
2026-06-25 Cipla sends second Notice Letter to Gilead
2026-06-26 Original Complaint filed by Gilead
2026-07-01 Cipla sends third Notice Letter to Gilead
2026-07-14 U.S. Patent No. 12,678,408 ('408 Patent) issues
2026-07-14 Amended Complaint filed by Gilead

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

U.S. Patent No. 12,629,338 - "Pharmaceutical Formulations Comprising Tenofovir Alafenamide and Emtricitabine"

  • Patent Identification: U.S. Patent No. 12,629,338, issued May 19, 2026.

The Invention Explained

  • Problem Addressed: The patent describes the need for improved combination antiretroviral therapies for HIV that optimize long-term safety, tolerability, and patient adherence ʼ338 Patent, col. 1:29-37 A specific challenge is formulating stable oral tablets with multiple active ingredients while reducing the total amount of excipients and overall tablet size, which can be burdensome for patients to swallow ʼ338 Patent, col. 1:46-56
  • The Patented Solution: The invention is a solid oral dosage form, specifically a tablet, that combines tenofovir alafenamide (TAF) and emtricitabine (FTC) in a formulation with a total weight significantly less than previous combination therapies ʼ338 Patent, abstract ʼ338 Patent, col. 1:50-65 The patent discloses specific formulations, including weight ranges and excipient compositions, that achieve the desired stability and reduced size ʼ338 Patent, col. 2:1-10
  • Technical Importance: This technology enabled the creation of a smaller, single-tablet regimen for HIV treatment, which represents a clinical advantage by potentially improving patient convenience and long-term compliance ʼ338 Patent, col. 8:50-58

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 Compl. ¶50
  • Independent Claim 1 of the '338 Patent recites:
    • A tablet consisting of: 25 mg tenofovir alafenamide, or a pharmaceutically acceptable salt thereof;
    • 200 mg emtricitabine, or a pharmaceutically acceptable salt thereof;
    • one or more excipients selected from a disintegrant, a lubricant, and a filler, or any combination thereof;
    • an optional polymeric coating;
    • wherein the tablet does not contain starch; and
    • wherein the tablet has a total weight of less than 600 mg.
  • The complaint reserves the right to assert other claims Compl. ¶50

U.S. Patent No. 12,648,911 - "Pharmaceutical Formulations Comprising Tenofovir Alafenamide and Emtricitabine"

  • Patent Identification: U.S. Patent No. 12,648,911, issued June 9, 2026.

The Invention Explained

  • Problem Addressed: The problem is identical to that described in the '338 Patent: the need for smaller, more convenient, and stable combination oral therapies for HIV ʼ911 Patent, col. 1:15-43
  • The Patented Solution: The patent claims a method of treating HIV by administering a tablet containing TAF and FTC. The invention identifies a specific relationship between the concentration of TAF and its stability, claiming a tablet where TAF constitutes a particular percentage of the tablet core's weight ʼ911 Patent, abstract ʼ911 Patent, col. 18:21-45 This approach claims to provide a stable and effective formulation in a reduced tablet size.
  • Technical Importance: As with the '338 Patent, this invention provides a basis for a smaller single-tablet regimen, which can improve patient adherence to lifelong HIV therapy ʼ911 Patent, col. 8:50-58

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 Compl. ¶58
  • Independent Claim 1 of the '911 Patent recites:
    • A method of treating an HIV infection, wherein the method comprises administering to a human a tablet consisting of:
    • (a) a tablet core consisting of: 25 mg tenofovir alafenamide, or a pharmaceutically acceptable salt thereof; 200 mg emtricitabine, or a pharmaceutically acceptable salt thereof; and one or more excipients; wherein about 4% to about 12% by weight of the tablet core is the tenofovir alafenamide, or a pharmaceutically acceptable salt thereof; and
    • (b) an optional coating.
  • The complaint reserves the right to assert other claims Compl. ¶58

U.S. Patent No. 12,661,323 - "Pharmaceutical Formulations Comprising Tenofovir Alafenamide and Emtricitabine"

  • Patent Identification: U.S. Patent No. 12,661,323, issued June 23, 2026 Compl. ¶30
  • Technology Synopsis: The patent addresses the technical challenge of creating a stable, combination oral tablet for HIV treatment containing TAF and FTC ʼ323 Patent, col. 1:15-24 The invention provides a solution by defining a specific formulation, including a total tablet weight of less than 600 mg and the exclusion of starch, to create a smaller, more convenient dosage form ʼ323 Patent, abstract '323 Patent, claim 1
  • Asserted Claims: At least independent claim 1 Compl. ¶67
  • Accused Features: Cipla's proposed generic tablets containing TAF and FTC are alleged to embody the claimed formulation, including the specified active ingredients, excipients, lack of starch, and total tablet weight Compl. ¶¶37-47

U.S. Patent No. 12,678,408 - "Pharmaceutical Formulations Comprising Tenofovir Alafenamide and Emtricitabine"

  • Patent Identification: U.S. Patent No. 12,678,408, issued July 14, 2026 Compl. ¶31
  • Technology Synopsis: The complaint does not provide sufficient detail for analysis of the specific technology. Based on its title and family relationship to the other patents-in-suit, it likely concerns stable oral formulations of TAF and FTC for HIV treatment.
  • Asserted Claims: At least independent claim 1 Compl. ¶75
  • Accused Features: Cipla's proposed generic tablets containing TAF and FTC are alleged to infringe the claims of the '408 Patent Compl. ¶76

III. The Accused Instrumentality

Product Identification

The accused products are Cipla's proposed emtricitabine/tenofovir alafenamide oral tablets in 120 mg/15 mg and 200 mg/25 mg strengths, submitted for FDA approval under 505(b)(2) Application No. 220756 ("Cipla's 505(b)(2) Products") Compl. ¶6

Functionality and Market Context

  • The accused products are oral tablets intended for the treatment of HIV-1 infection and for pre-exposure prophylaxis (PrEP) to reduce the risk of HIV-1 infection Compl. ¶48 The complaint alleges, based on UK regulatory filings and its 505(b)(2) application, that the accused 200 mg/25 mg product contains TAF and FTC with specific excipients, including lactose, crospovidone, and magnesium stearate, and features a polymeric coating Compl. ¶39 Compl. ¶42 Compl. ¶44 The complaint alleges the TAF is in the form of TAF fumarate Compl. ¶40 and that the total tablet weight is less than 600 mg Compl. ¶47
  • The complaint provides a chemical structure diagram for tenofovir alafenamide (TAF), the core phosphonamidate prodrug at the center of the dispute Compl. p. 7
  • The complaint alleges Cipla is seeking to benefit from Gilead's investments by marketing a competing product prior to patent expiration, leveraging Gilead's clinical data for DESCOVY® through the 505(b)(2) pathway Compl. ¶6

IV. Analysis of Infringement Allegations

12,629,338 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A tablet consisting of: 25 mg tenofovir alafenamide, or a pharmaceutically acceptable salt thereof... Cipla's proposed product is a tablet containing 25 mg of TAF. ¶37 col. 65:42-44
200 mg emtricitabine, or a pharmaceutically acceptable salt thereof... Cipla's proposed product is a tablet containing 200 mg of FTC. ¶37 col. 65:45-47
one or more excipients selected from a disintegrant, a lubricant, and a filler... Cipla's product allegedly contains excipients including crospovidone (disintegrant), magnesium stearate (lubricant), and lactose (filler). ¶39; ¶42 col. 65:48-50
an optional polymeric coating Cipla's product allegedly contains a polymeric coating. ¶44 col. 65:51-51
wherein the tablet does not contain starch Cipla's product allegedly does not include starch. ¶43 col. 65:52-53
wherein the tablet has a total weight of less than 600 mg The total tablet weight of Cipla's product is alleged to be less than 600 mg. ¶47 col. 65:54-55

12,648,911 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of treating an HIV infection, wherein the method comprises administering to a human a tablet... Cipla's proposed label allegedly instructs physicians to administer the product for the treatment of HIV-1 infection. ¶48 col. 37:4-9
a tablet core consisting of: 25 mg tenofovir alafenamide, or a pharmaceutically acceptable salt thereof... Cipla's proposed 200 mg/25 mg product is a tablet containing a 25 mg dose of TAF. ¶37 col. 66:42-44
200 mg emtricitabine, or a pharmaceutically acceptable salt thereof... Cipla's proposed 200 mg/25 mg product is a tablet containing a 200 mg dose of FTC. ¶37 col. 66:45-47
wherein about 4% to about 12% by weight of the tablet core is the tenofovir alafenamide... The complaint alleges on information and belief that about 4% to 12% by weight of the tablet core of Cipla's product is TAF. ¶45 col. 66:49-52
an optional coating Cipla's product allegedly contains a polymeric coating. ¶44 col. 66:53-53

Identified Points of Contention

  • Scope Questions: A potential question for the court is the proper construction of "about 4% to about 12% by weight" in claim 1 of the '911 Patent. The parties may dispute the scope of the term "about" and whether Cipla's formulation, whatever its exact percentage, falls within the claimed range.
  • Technical Questions: A primary factual dispute may concern the composition of Cipla's product. The complaint makes several allegations regarding the product's specific formulation "on information and belief," including the exact weight percentage of TAF in the tablet core Compl. ¶45 and the total tablet weight Compl. ¶47 What evidence Gilead can produce in discovery to prove these alleged characteristics will be critical to its infringement case.

V. Key Claim Terms for Construction

  • The Term: "total weight of less than 600 mg" (from claim 1 of the '338 Patent)

    • Context and Importance: This quantitative limitation is a bright-line test for infringement. The allegation that Cipla's product meets this limitation is central to the infringement theory for the '338 Patent Compl. ¶47 Practitioners may focus on this term because its definition-specifically, what components are included in the "total weight"-will determine if there is a literal match.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification repeatedly emphasizes the goal of reducing overall tablet size to improve patient convenience ('338 Patent, col. 1:46-56; '338 Patent, col. 8:50-58). This context may support an interpretation that "total weight" refers to the final, swallowable tablet, including any "optional polymeric coating" mentioned in the claim.
      • Evidence for a Narrower Interpretation: A party might point to specific examples in the patent, such as the 450 mg core weight tablet in Example 1 ('338 Patent, col. 43:40-45), to argue the claim should be interpreted in light of specific embodiments. However, the claim language "the tablet has a total weight" appears unambiguous and would likely be construed to mean the weight of the entire final product.

  • The Term: "about 4% to about 12% by weight of the tablet core" (from claim 1 of the '911 Patent)

    • Context and Importance: Infringement of the '911 Patent hinges on Cipla's product falling within this specific compositional range Compl. ¶45 The term "about" introduces indefiniteness, making its construction critical. Practitioners may focus on this term because the case could turn on whether Cipla's formulation is "about" 12% or just outside that boundary.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification presents the relationship between TAF concentration and stability as a key discovery ('911 Patent, col. 18:21-45). A party could argue "about" should be interpreted broadly to encompass any formulation that capitalizes on this inventive stability principle, even if slightly outside the numerical bounds.
      • Evidence for a Narrower Interpretation: The patent includes Figure 1, which plots impurity increase against "% TAF loading" ('911 Patent, Fig. 1). A party could argue that the scope of "about" should be limited to the range shown in the patent's data to achieve the demonstrated stability benefit, potentially narrowing the term's reach.

VI. Other Allegations

Indirect Infringement

The complaint alleges that Cipla will induce infringement of the method claims of the '911 Patent. The basis for this allegation is that Cipla's proposed product label will instruct physicians and healthcare providers to administer the product for HIV treatment, which is the infringing method recited in the claims Compl. ¶48 Compl. ¶60 Contributory infringement is also alleged, on the basis that Cipla's product will not have substantial non-infringing uses Compl. ¶61

Willful Infringement

The complaint does not contain an explicit count for willful infringement. However, it does allege that Cipla has "actual or constructive knowledge" of the patents-in-suit, based on their listing in the FDA's Orange Book for DESCOVY® and notice letters sent by Cipla Compl. ¶35 Compl. ¶53 Compl. ¶62 These allegations could serve as a predicate for a future claim for enhanced damages under 35 U.S.C. § 284.

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

  • A core issue will be one of definitional scope: can the quantitative limitations in the claims, such as "total weight of less than 600 mg" and "about 4% to about 12% by weight," be construed to read on the precise physical and chemical characteristics of Cipla's proposed product? The court's interpretation of these numerical boundaries, particularly the term "about," will be pivotal.
  • A key evidentiary question will be one of compositional proof: what evidence will Gilead be able to obtain and present to prove the specific formulation details of Cipla's product, such as the exact weight percentage of TAF in the tablet core? As many of these allegations are made on "information and belief," the case will likely turn on facts uncovered during discovery.
  • A central legal question will be one of infringement pathway: how will the different infringement theories play out across the asserted patents? The case involves both composition of matter claims, which require detailed product analysis, and method of use claims, where infringement can potentially be established through the defendant's proposed product labeling, raising the question of which theory provides a more direct path to a finding of infringement.
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