DCT

1:19-cv-00317

Merck Sharp & Dohme Corp v. Watson Laboratories Inc

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-00317, D. Del., 02/13/2019
  • Venue Allegations: The complaint alleges venue is proper because Teva USA is a Delaware corporation, and Watson and Teva Israel are subject to personal jurisdiction in the district and have previously consented to jurisdiction by litigating in the district.
  • Core Dispute: Plaintiff alleges that Defendants' Abbreviated New Drug Application (ANDA) submissions to the FDA for generic versions of the diabetes drugs JANUVIA® and JANUMET® constitute an act of infringement of patents covering a specific crystalline salt of sitagliptin and a combination drug formulation.
  • Technical Context: The technology concerns oral pharmaceutical treatments for Type 2 diabetes, specifically involving a dipeptidyl peptidase-IV (DPP-4) inhibitor, sitagliptin, both as a standalone therapy and in combination with metformin.
  • Key Procedural History: The lawsuit was triggered by Defendants' ANDA submissions containing Paragraph IV certifications, which assert that Plaintiff's patents are invalid, unenforceable, or will not be infringed by the proposed generic products. Subsequent to the complaint filing, U.S. Patent No. 7,326,708 survived an Inter Partes Review (IPR) proceeding (IPR2020-00040 and related cases), in which the Patent Trial and Appeal Board found asserted claims 1-4 to be patentable.

Case Timeline

Date Event
2003-06-24 U.S. Patent No. 7,326,708 Priority Date
2005-12-16 U.S. Patent No. 8,414,921 Priority Date
2008-02-05 U.S. Patent No. 7,326,708 Issued
2011-01-06 Watson sends Notice Letter for '327 ANDA (generic JANUVIA®)
2011-02-07 Watson sends First Notice Letter for '365 ANDA (generic JANUMET®)
2013-04-09 U.S. Patent No. 8,414,921 Issued
2014-10-29 Watson sends Second Notice Letter for '365 ANDA
2019-02-13 Complaint Filed

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

U.S. Patent No. 7,326,708 - “Phosphoric Acid Salt of a Dipeptidyl Peptidase-IV Inhibitor,” issued Feb. 5, 2008

The Invention Explained

  • Problem Addressed: The patent addresses the need for effective treatments for Type 2 diabetes by inhibiting the enzyme dipeptidyl peptidase-IV (DP-IV), which inactivates key hormones involved in glucose regulation (’708 Patent, col. 1:30-44).
  • The Patented Solution: The invention is not the underlying active compound itself, but rather a specific, novel salt form: the dihydrogenphosphate salt of the DP-IV inhibitor 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine. The patent describes that this salt, particularly in its crystalline monohydrate form, has advantageous properties for manufacturing pharmaceutical compositions, such as improved physical and chemical stability (’708 Patent, Abstract; col. 2:5-16).
  • Technical Importance: Creating a stable and consistently manufacturable salt of an active pharmaceutical ingredient is a critical step in drug development, as it directly impacts the drug's shelf-life, purity, and suitability for formulation into reliable dosage forms (’708 Patent, col. 2:5-16).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶¶ 47, 67).
  • Independent Claim 1 requires:
    • A dihydrogenphosphate salt of 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine of structural formula I, or a hydrate thereof.
  • The complaint alleges infringement of "one or more claims," suggesting dependent claims may also be at issue (Compl. ¶¶ 47, 67).

U.S. Patent No. 8,414,921 - “Pharmaceutical Compositions of Combinations of Dipeptidyl Peptidase-4 Inhibitors with Metformin,” issued Apr. 9, 2013

The Invention Explained

  • Problem Addressed: The patent background notes that Type 2 diabetes is a progressive disease where monotherapy often becomes insufficient, requiring combination therapy. The complexity of taking multiple, separate pills can reduce patient adherence (’921 Patent, col. 1:16-29).
  • The Patented Solution: The invention provides a fixed-dose combination tablet that includes both a DPP-4 inhibitor (sitagliptin) and metformin. The claims define specific pharmaceutical formulations by reciting percentage-by-weight ranges for the active ingredients and various excipients (e.g., lubricants, binders, surfactants) to create a stable and effective single-tablet product (’921 Patent, Abstract; col. 3:20-30).
  • Technical Importance: Developing fixed-dose combination therapies simplifies treatment regimens for chronic conditions, which can lead to improved patient compliance and better management of the disease (’921 Patent, col. 1:29-34).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶¶ 41, 86).
  • Independent Claim 1 requires a pharmaceutical composition comprising:
    • (a) about 3 to 20% by weight of sitagliptin, or a pharmaceutically acceptable salt thereof;
    • (b) about 25 to 94% by weight of metformin hydrochloride;
    • (c) about 0.1 to 10% by weight of a lubricant;
    • (d) about 0 to 35% by weight of a binding agent;
    • (e) about 0.5 to 1% by weight of a surfactant; and
    • (f) about 5 to 15% by weight of a diluent.
  • The complaint alleges infringement of "one or more claims," suggesting dependent claims may also be at issue (Compl. ¶86).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentalities are Defendants' generic drug products detailed in two ANDA submissions:
    • ANDA No. 202327 ("Watson's '327 ANDA Product"), a generic version of JANUVIA® (Compl. ¶¶ 2-3).
    • ANDA No. 202365 ("Watson's '365 ANDA Product"), a generic version of JANUMET® (Compl. ¶¶ 4-6).
  • Functionality and Market Context:
    • The '327 ANDA Product is an oral tablet formulation containing sitagliptin phosphate as the active ingredient (Compl. ¶¶ 2, 46).
    • The '365 ANDA Product is an oral tablet formulation containing a combination of metformin hydrochloride and sitagliptin phosphate (Compl. ¶¶ 4, 66).
    • The complaint alleges that these ANDAs were submitted for the purpose of obtaining FDA approval to commercially manufacture and sell these generic products in the U.S. prior to the expiration of the patents-in-suit, which is the statutory basis for an infringement action under the Hatch-Waxman Act (Compl. ¶1).
  • Visual Evidence: No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'708 Patent Infringement Allegations

The complaint alleges that Defendants' notice letters did not contest that their proposed generic products infringe claim 1 of the ’708 Patent (Compl. ¶¶ 48, 68). The infringement theory is based on the composition of the ANDA products.

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A dihydrogenphosphate salt of 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine of structural formula I... or a hydrate thereof. Both the '327 ANDA Product and the '365 ANDA Product are alleged to contain "sitagliptin phosphate as an active ingredient," which is the salt recited in the claim. ¶¶46, 66 col. 2:44-62
  • Identified Points of Contention:
    • Validity vs. Infringement: As the complaint alleges that infringement of claim 1 was not contested, the central dispute for the '708 patent will likely concern its validity and/or enforceability, which Defendants challenged in their Paragraph IV certifications (Compl. ¶¶ 45, 65).
    • Scope Questions: A potential issue, should infringement become contested, is the scope of the term "hydrate thereof." The '708 patent specification extensively discusses a "crystalline monohydrate," which raises the question of whether "hydrate thereof" is limited to that specific disclosed embodiment or covers other hydrated forms.

'921 Patent Infringement Allegations

The complaint alleges that Defendants' notice letter did not contest that their proposed '365 ANDA Product infringes claim 1 of the ’921 Patent (Compl. ¶87). The infringement theory is based on the allegation that the product contains the claimed ingredients in the claimed amounts.

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a pharmaceutical composition comprising: (a) about 3 to 20% by weight of sitagliptin, or a pharmaceutically acceptable salt thereof; (b) about 25 to 94% by weight of metformin hydrochloride... The complaint alleges Watson's '365 ANDA Product "includes the same or equivalent ingredients as recited in claim 1 of the '921 patent in the same or equivalent amounts." ¶86 col. 12:50-54
(c) about 0.1 to 10% by weight of a lubricant The '365 ANDA Product is alleged to contain a lubricant within the claimed range. ¶86 col. 12:55-56
(d) about 0 to 35% by weight of a binding agent The '365 ANDA Product is alleged to contain a binding agent within the claimed range. ¶86 col. 12:57-58
(e) about 0.5 to 1% by weight of a surfactant The '365 ANDA Product is alleged to contain a surfactant within the claimed range. ¶86 col. 12:59-60
(f) about 5 to 15% by weight of a diluent The '365 ANDA Product is alleged to contain a diluent within the claimed range. ¶86 col. 12:61-62
  • Identified Points of Contention:
    • Scope Questions: A primary issue for construction will be the term "about," which modifies all percentage ranges in claim 1. The definition of this term will be critical if the accused formulation's percentages are close to, but not exactly within, the recited numerical limits.
    • Technical Questions: The complaint's use of the phrase "same or equivalent ingredients" raises the question of whether the excipients in the accused product are identical to those disclosed in the '921 patent's embodiments or are merely functionally similar, potentially setting up a dispute over literal infringement versus infringement under the doctrine of equivalents (Compl. ¶86).

V. Key Claim Terms for Construction

For the '708 Patent:

  • The Term: "hydrate thereof"
  • Context and Importance: This term appears in claim 1 and defines the scope of the claimed salt beyond its anhydrous form. The '708 patent's specification places significant emphasis on a specific "crystalline monohydrate." Practitioners may focus on this term because its construction will determine whether the claim is limited to the heavily disclosed monohydrate or can read on other potential hydrated forms (e.g., dihydrates, amorphous hydrates) that an accused product might contain.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The plain language "a hydrate" does not, on its face, limit the claim to a specific stoichiometry or crystalline form (’708 Patent, col. 16:15-16).
    • Evidence for a Narrower Interpretation: The specification repeatedly and specifically identifies the "crystalline monohydrate" as the invention that provides advantageous properties, which could be used to argue that the claim scope should be interpreted as being limited to that disclosed embodiment (’708 Patent, Abstract; col. 2:3-5).

For the '921 Patent:

  • The Term: "about"
  • Context and Importance: This term is used to qualify every numerical range in independent claim 1. Its interpretation is central to determining the scope of literal infringement. Practitioners may focus on this term because if the Defendants' formulation falls just outside the specified percentages, the entire infringement analysis could hinge on whether the formulation is nevertheless "about" that percentage.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patentee's explicit choice to use the word "about" in the claims suggests an intent to cover values that are reasonably close to the stated ranges, not just the exact numbers themselves (’921 Patent, col. 12:50-62).
    • Evidence for a Narrower Interpretation: The patent does not provide an explicit definition of "about." The examples provided in the specification use precise numerical values for the formulation components, which a party could argue suggests a high degree of precision in the field and supports a narrow construction of "about" (’921 Patent, col. 9-11, Examples 1-7).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon FDA approval, Defendants will induce infringement by providing product labeling that instructs medical professionals and patients to use the generic products in an infringing manner (Compl. ¶¶ 53, 73, 92). It also alleges contributory infringement, stating the products are especially made for an infringing use and are not staple articles of commerce with substantial non-infringing uses (Compl. ¶¶ 54, 74, 93).
  • Willful Infringement: Willfulness is alleged based on Defendants' "full knowledge" of the patents, evidenced by their ANDA notice letters sent to Merck, and their continued intent to market the generic products notwithstanding this knowledge (Compl. ¶¶ 57, 77, 96).

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

  • A core issue will be one of patent validity: The complaint alleges that Defendants did not contest infringement of the asserted claims in their pre-suit notice letters. Assuming this holds, the case will likely center on Defendants' asserted defenses that the '708 and '921 patents are invalid or unenforceable. The specific grounds for these defenses will be a central focus of the litigation.
  • A key question of claim interpretation for the '921 patent will be the scope of the term "about." How the court construes this term will define the boundaries of the claimed formulation ranges and will likely be dispositive if the accused product's composition is close to, but not strictly within, the recited percentages.
  • A final question will be one of evidentiary proof: While infringement is allegedly not contested, if it becomes a disputed issue, Merck will need to present evidence that the proposed generic products meet every limitation of the asserted claims, including potentially proving that different excipients in the accused product are "equivalent" to those recited in the '921 patent's claims.