DCT

2:20-cv-02909

Merck Sharp & Dohme BV v. DR Reddys Laboratories Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:20-cv-02909, D.N.J., 03/16/2020
  • Venue Allegations: Venue is alleged to be proper in the District of New Jersey because Defendant Dr. Reddy's Laboratories, Inc. is incorporated and has its principal place of business in New Jersey, and its co-defendant is a foreign entity.
  • Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to market a generic version of the drug Bridion® (sugammadex) constitutes an act of infringement of a patent covering the drug's active ingredient.
  • Technical Context: The technology involves chemically modified cyclodextrins used as reversal agents to rapidly and safely counteract the effects of neuromuscular blocking agents administered during surgery.
  • Key Procedural History: This action was filed under the Hatch-Waxman Act, triggered by Defendants' notice letter and Paragraph IV certification asserting that the patent-in-suit is invalid, unenforceable, or not infringed. The complaint notes that the asserted patent is a reissue of U.S. Patent No. 6,670,340 and that its term was extended by five years via a Patent Term Extension (PTE), with a listed expiration of January 27, 2026.

Case Timeline

Date Event
1999-11-29 '733' Patent Priority Date (via parent '340 patent)
2003-12-30 Original U.S. Patent No. 6,670,340 Issued
2014-01-28 Reissue Patent No. RE44,733 Issued
2015-12-15 FDA Approval for Bridion® NDA
2020-02-04 PTO Issues Notice of Final Determination for PTE
2020-02-11 DRL Notifies Merck of ANDA Filing via Notice Letter
2020-03-16 Complaint Filed

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

U.S. Reissue Patent No. RE44,733 - "6-Mercapto-Cyclodextrin Derivatives: Reversal Agents For Drug-Induced Neuromuscular Block"

The Invention Explained

  • Problem Addressed: The patent addresses the risks and side effects associated with traditional agents used to reverse surgically-induced muscle paralysis. These prior agents, known as anticholinesterase inhibitors, work by increasing levels of acetylcholine, which can cause undesirable effects like bradycardia and hypotension and cannot reliably reverse a "profound block" of neuromuscular function (’733 Patent, col. 2:1-26).
  • The Patented Solution: The invention proposes a different mechanism: using specifically designed cyclodextrin derivatives as "chemical chelators" that directly encapsulate and inactivate the neuromuscular blocking agent (NMBA) molecules (’733 Patent, col. 2:29-32). This guest-host complex formation physically removes the NMBA from the neuromuscular junction, reversing the paralysis without altering acetylcholine levels and their associated side effects (’733 Patent, col. 2:32-44). The core of the invention is the chemical structure of these modified cyclodextrins, defined by Formula I, which are tailored to bind NMBA's.
  • Technical Importance: This approach represented a novel method for reversing neuromuscular blockade that offered the potential for faster, more reliable recovery, including from profound paralysis, with a more favorable side-effect profile compared to existing agents (Compl. ¶38).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶50).
  • Independent Claim 1 is a composition of matter claim directed to a 6-mercapto-cyclodextrin derivative with a specific chemical structure defined by:
    • A cyclodextrin core (defined by variables m and n where m+n=7 or 8).
    • A linker group R, which is a (C1-6)alkylene or a substituted phenylene group.
    • A terminal functional group X, selected from a Markush group including COOH, CONHR₁, SO₂OH, and others.
  • The complaint notes that Defendants did not specifically contest infringement of claims 1-5 and 11-14 in their notice letter (Compl. ¶51).

III. The Accused Instrumentality

Product Identification

  • Purported generic versions of Bridion® (sugammadex) injection in 200 mg/2 mL and 500 mg/5 mL strengths, as described in Defendants' ANDA No. 214236 ("DRL ANDA Products") (Compl. ¶7).

Functionality and Market Context

  • The DRL ANDA Products are intended to be generic equivalents of Merck's Bridion® and are indicated for the reversal of neuromuscular blockade induced by certain drugs in adults undergoing surgery (Compl. ¶43). The active ingredient in the accused products is identified as sugammadex (Compl. ¶46), which the complaint alleges is the chemical compound 6-per-deoxy-6-per-(2-carboxyethyl)thio-γ-cyclodextrin, covered by the '733' patent (Compl. ¶¶33-34, 50).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

The complaint's infringement theory is based on direct chemical identity. It alleges that the active ingredient in the DRL ANDA Products, sugammadex, is a compound that falls within the scope of the claims of the ’733 patent.

RE44,733 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A 6-mercapto-cyclodextrin derivative having the general formula I The active ingredient of the DRL ANDA Products is sugammadex, which is alleged to be the compound 6-per-deoxy-6-per-(2-carboxyethyl)thio-γ-cyclodextrin. ¶¶34, 46, 50 col. 4:51-53
wherein m is 0-7 and n is 1-8 and m+n=7 or 8 Sugammadex is a γ-cyclodextrin derivative, meaning it has 8 glucose units (n=8, m=0), which satisfies the m+n=8 requirement. ¶¶33-34, 50 col. 4:40-44
R is (C₁-₆)alkylene... The structure of sugammadex contains a (2-carboxyethyl)thio group, where the linker 'R' is an ethylene group, which is a (C₁-₆)alkylene. ¶¶33-34, 50 col. 4:20-27
X is COOH... The structure of sugammadex contains a (2-carboxyethyl)thio group, where the terminal group 'X' is a carboxy group (COOH). ¶¶33-34, 50 col. 3:19-22
  • Identified Points of Contention:
    • Technical Questions: The primary technical question, from an infringement perspective, is one of chemical identity: will discovery confirm that the chemical compound described in Defendants' ANDA is, in fact, the specific 6-mercapto-cyclodextrin derivative defined by at least one of the asserted claims? The complaint alleges this is the case, and Defendants' notice letter reportedly states the active ingredient is sugammadex (Compl. ¶46).
    • Scope Questions: While infringement of the compound claim appears to be the central allegation, a dispute could arise over the interpretation of method-of-use claims, should they be asserted. A question would be whether Defendants' proposed product label instructs physicians to use the generic drug in a manner that directly reads on the patented methods.

V. Key Claim Terms for Construction

  • The Term: "(C₁-₆)alkylene"
  • Context and Importance: This term, appearing in independent claim 1, defines the chemical linker 'R' connecting the cyclodextrin's sulfur atom to the terminal functional group 'X'. The interpretation of this term dictates the length and structure of the linker, which is a critical feature of the claimed molecule. Practitioners may focus on this term because the specific properties of the linker can affect the compound's ability to bind the target drug, its solubility, and its overall efficacy.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides an explicit definition: "The term (C₁-₆)alkylene as used in the definition of formula I means a branched or straight chain bivalent carbon radical containing 1-6 carbon atoms, such as methylene, ethylene (1,2-ethandiyl), propylene... and 1,6-hexanediyl." (’733 Patent, col. 4:20-27). This language supports an interpretation covering a range of structures.
    • Evidence for a Narrower Interpretation: A party seeking a narrower construction might argue that the term's scope should be functionally limited to those alkylene chains that achieve the patent's stated purpose of reversing neuromuscular blockade, or that it should be understood primarily in light of the specific embodiments disclosed, such as the ethylene linker found in the preferred compound "6-per-deoxy-6-per-(2-carboxyethyl)thio-γ-cyclodextrin" (’733 Patent, col. 4:51-53) and in multiple examples (e.g., Example 4).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement under 35 U.S.C. § 271(b). The factual basis is the allegation that Defendants will market and distribute the DRL ANDA Products with a product label and instructions that are "substantially similar to the instructions in the prescribing information for Bridion®," and that following these instructions will cause healthcare professionals to directly infringe the patent (Compl. ¶57).
  • Willful Infringement: Willfulness is alleged based on Defendants' knowledge of the '733' patent, as evidenced by their filing of a Paragraph IV certification, and their alleged lack of a "reasonable basis for believing that they would not be liable for direct infringement" (Compl. ¶62).

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

  • A central issue will be one of validity: given that the complaint alleges the accused product's active ingredient is the claimed compound, the case will likely hinge on whether Defendants can prove by clear and convincing evidence that the asserted claims of the '733' patent are invalid (e.g., for obviousness or lack of written description), as asserted in their Paragraph IV certification (Compl. ¶45).
  • A key evidentiary question will be one of chemical confirmation: what will discovery reveal about the exact chemical structure and composition of the drug product described in ANDA No. 214236? While the complaint alleges identity, the ultimate proof will depend on the technical data submitted to the FDA and produced in litigation.
  • A final question for the court will be one of intent for inducement: assuming direct infringement by end-users is established, does the content of Defendants' proposed product labeling demonstrate a specific intent to encourage infringement of any asserted method claims, or is it merely a recitation of the FDA-approved indications for the reference listed drug?