DCT

1:22-cv-00377

Merck Sharp & Dohme Corp v. Aurobindo Pharma Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:22-cv-00377, D. Del., 03/23/2022
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Aurobindo Pharma USA, Inc. is a Delaware corporation and therefore resides in the district, and Defendant Aurobindo Pharma Limited is a foreign corporation that may be sued in any judicial district.
  • Core Dispute: Plaintiffs allege that Defendant’s submission of an Abbreviated New Drug Application (ANDA) for a generic version of the diabetes drug Steglatro® (ertugliflozin) constitutes an act of infringement of a patent covering the ertugliflozin compound.
  • Technical Context: The technology relates to sodium-glucose co-transporter 2 (SGLT2) inhibitors, a class of pharmaceutical compounds used to treat type 2 diabetes by promoting the excretion of glucose in the urine.
  • Key Procedural History: The lawsuit was initiated under the Hatch-Waxman Act following Aurobindo's submission of ANDA No. 216947 with a Paragraph IV certification, asserting that the patent-in-suit is invalid, unenforceable, or will not be infringed by its proposed generic product. The patent-in-suit is listed in the FDA’s "Orange Book" for the branded drug Steglatro®.

Case Timeline

Date Event
2008-08-28 '580 Patent Priority Date
2011-12-20 '580 Patent Issue Date
2022-02-08 Aurobindo Notice Letter Date
2022-03-23 Complaint Filing Date

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

U.S. Patent No. 8,080,580 - “Dioxa-bicyclo[3.2.1]octane-2,3,4-triol derivatives,”

  • Patent Identification: U.S. Patent No. 8,080,580, “Dioxa-bicyclo[3.2.1]octane-2,3,4-triol derivatives,” issued December 20, 2011.

The Invention Explained

  • Problem Addressed: The patent identifies a need for new, effective, and safe medications to treat or prevent obesity and its associated co-morbidities, particularly type 2 diabetes (’580 Patent, col. 1:21-37).
  • The Patented Solution: The invention provides a specific class of chemical compounds, dioxa-bicyclo[3.2.1]octane-2,3,4-triol derivatives, that function as sodium-glucose co-transport 2 (SGLT2) inhibitors (’580 Patent, Abstract). By inhibiting SGLT2, these compounds block the reabsorption of glucose in the kidneys, causing excess glucose to be excreted in the urine, which in turn helps to lower blood glucose levels (’580 Patent, col. 1:38-47).
  • Technical Importance: This therapeutic approach was considered attractive as it offered a means to improve diabetic conditions without the common side effects of increasing body weight or the risk of hypoglycemia (’580 Patent, col. 1:47-51).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and reserves the right to assert additional claims, noting that Defendant’s notice letter did not contest infringement of claims 1-8, 10-14, 16, 18, and 20 (Compl. ¶35, 37).
  • Independent Claim 1 recites:
    • A compound of Formula (A) or Formula (B);
    • Wherein R¹ is a member of a first Markush group including H, (C1-C4)alkyl, Cl, and F, among others;
    • And wherein R² is a member of a second Markush group including (C1-C4)alkoxy, (C2-C4)alkynyl, and Cl, among others.

III. The Accused Instrumentality

Product Identification

  • Aurobindo’s Proposed ANDA Product, which is a generic version of Steglatro® tablets in 5 and 15 mg strengths (Compl. ¶1).

Functionality and Market Context

  • The active pharmaceutical ingredient in the accused product is ertugliflozin (Compl. ¶28). The product is intended to be marketed as a bioequivalent to the branded drug Steglatro®, which is used to improve glycemic control in adults with type 2 diabetes (Compl. ¶18, 29). The complaint alleges that Aurobindo will market and sell the product upon receiving FDA approval (Compl. ¶40).

IV. Analysis of Infringement Allegations

The complaint alleges that the ertugliflozin compound contained in Aurobindo's Proposed ANDA Product falls within the scope of at least claim 1 of the ’580 patent (Compl. ¶34-35). The complaint provides a diagram of the chemical structures of Formula (A) and Formula (B) from the asserted claim (Compl. ¶33, p. 7).

'580 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A compound of Formula (A) or Formula (B) The active ingredient in the Proposed ANDA Product is ertugliflozin, which is alleged to be a compound of Formula (A). The patent specification explicitly identifies ertugliflozin by its chemical name, (1S,2S,3S,4R,5S)-5-[4-chloro-3-(4-ethoxy-benzyl)-phenyl]-1-hydroxymethyl-6,8-dioxa-bicyclo[3.2.1]octane-2,3,4-triol, as a "Specific compound[] of Formula (A)." ¶28, 34 col. 3:57-65
wherein R¹ is H, (C1-C4)alkyl, (C1-C4)alkoxy, Cl, F, cyano, fluoro-substituted (C1-C2)alkyl, (C1-C4)alkyl-SO₂—, or (C3-C6)cycloalkyl The ertugliflozin compound contains a chloro (Cl) substituent at the 4-position of its phenyl ring, which corresponds to R¹ in Formula (A). The Markush group for R¹ in claim 1 explicitly includes "Cl". ¶28, 33, 34 col. 13:41-45
and R² is (C1-C4)alkyl, (C1-C4)alkoxy, (C2-C4)alkynyl, 3-oxetanyloxy, 3-tetrahydrofuranyloxy, Cl, F, cyano, fluoro-substituted (C1-C2)alkyl, (C1-C4)alkyl-SO₂—, (C3-C6)cycloalkyl, or a (C5-C6)heterocycle having 1 or 2 heteroatoms each independently selected from N, O, or S. The ertugliflozin compound contains a "4-ethoxy-benzyl" substituent at the 3-position of its phenyl ring. The complaint alleges this compound infringes, which suggests this substituent is alleged to correspond to R². While a benzyl-containing group is not expressly listed in the Markush group for R², the patent specification's explicit identification of ertugliflozin as a species of Formula (A) may support this allegation. ¶28, 33, 34 col. 13:46-50

Identified Points of Contention

  • Scope Questions: A central dispute may arise over whether the ertugliflozin compound is covered by claim 1. The Markush group defining the R² substituent does not explicitly recite a benzyl-containing moiety, such as the "4-ethoxybenzyl" group present in ertugliflozin. This raises the question of whether the claim language itself excludes the accused compound. However, the patent specification explicitly lists ertugliflozin as a specific embodiment of Formula (A), which may support an argument that the claim was intended to cover it, potentially due to a scrivener's error in the claim language.

V. Key Claim Terms for Construction

  • The Term: "a compound of Formula (A) ... wherein ... R² is ..."
  • Context and Importance: The construction of the scope of the claimed genus, particularly with respect to the R² substituent, appears to be dispositive for infringement of claim 1. If the claim is construed narrowly based on the plain language of the Markush group, it may not read on ertugliflozin. If construed more broadly in light of the specification, it may. Practitioners may focus on this issue as it presents a potential conflict between the claim language and the specification's description of the invention.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides a list of "Specific compounds of Formula (A)" which includes "(1S,2S,3S,4R,5S)-5-[4-chloro-3-(4-ethoxy-benzyl)-phenyl]-1-hydroxymethyl-6,8-dioxa-bicyclo[3.2.1]octane-2,3,4-triol," the chemical name for ertugliflozin (’580 Patent, col. 3:57-65). A court may view this as a clear definition by example, indicating the inventor's intent for Formula (A) to encompass this specific compound.
    • Evidence for a Narrower Interpretation: The language of claim 1 provides an explicit and closed list (a Markush group) for the R² substituent that does not include any benzyl-containing groups (’580 Patent, col. 13:46-50). A party could argue that under the principle of claim differentiation and the rule that claims, not the specification, define the invention, this clear language cannot be expanded or altered by examples in the specification.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement, stating that Aurobindo's proposed product label will instruct healthcare providers to prescribe the product for infringing uses (Compl. ¶30, 42). It also alleges contributory infringement, asserting the product is especially made for a patented use and is not suitable for substantial non-infringing use (Compl. ¶43).
  • Willful Infringement: The complaint does not use the word "willful," but it alleges that Aurobindo had knowledge of the '580 patent, at least due to its listing in the FDA's Orange Book and the filing of its Paragraph IV certification (Compl. ¶41). The prayer for relief requests a declaration that the case is "exceptional" and an award of attorneys' fees, which is consistent with an allegation of egregious infringement (Compl. p. 11, ¶(e)).

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

  • A core issue will be one of claim construction and scope: Can the genus of compounds claimed in Claim 1 be construed to cover ertugliflozin, given that the claim’s explicit Markush definition for the R² substituent does not appear to encompass the "4-ethoxybenzyl" group present in the ertugliflozin molecule? The case may turn on whether the court finds the specific disclosure of ertugliflozin in the patent's specification sufficient to overcome the seemingly unambiguous language of the claim itself.
  • A second key question will be patent validity. While the complaint does not detail Aurobindo’s invalidity positions, Aurobindo’s Paragraph IV certification asserted that the '580 patent is invalid and/or unenforceable (Compl. ¶26). The specific grounds for this assertion (e.g., anticipation, obviousness) will likely form the central pillar of the defense.