DCT

1:26-cv-01166

Alnylam Pharma Inc v. Cipla USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: Alnylam Pharmaceuticals, Inc. v. Cipla USA Inc., 1:26-cv-01166, D. Del., 09/16/2026
  • Venue Allegations: Venue is asserted in Delaware because Defendant Cipla USA Inc. is a Delaware corporation, and Defendant Cipla Ltd. allegedly transacts business and directs activities in the state through its wholly-owned subsidiary, Cipla USA Inc.
  • Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to the FDA for a generic version of Plaintiff's drug AMVUTTRA® (vutrisiran) constitutes an act of infringement of five U.S. patents covering the drug's composition and methods of use.
  • Technical Context: The technology involves RNA interference (RNAi), specifically double-stranded RNA (dsRNA) agents designed to inhibit the expression of the transthyretin (TTR) gene for the treatment of TTR-associated diseases such as amyloidosis.
  • Key Procedural History: This is a Hatch-Waxman action triggered by Defendants' submission of an ANDA seeking to market a generic version of AMVUTTRA® prior to the expiration of the patents-in-suit. Plaintiff's filing follows receipt of a Notice Letter from Cipla, dated August 3, 2026, which included a Paragraph IV certification alleging that the patents-in-suit are invalid, unenforceable, and/or will not be infringed.

Case Timeline

Date Event
2014-08-20 Priority Date for '024 Patent
2015-07-31 Priority Date for '307, '501, '486, '628 Patents
2019-02-19 '307 Patent Issued
2020-04-07 '024 Patent Issued
2020-06-16 '501 Patent Issued
2022-03-29 '486 Patent Issued
2024-07-30 '628 Patent Issued
2026-08-03 Cipla's Notice Letter sent to Alnylam
2026-09-16 Complaint Filed

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

U.S. Patent No. 10,612,024 - "Modified Double-Stranded RNA Agents"

  • Patent Identification: U.S. Patent No. 10,612,024, "Modified Double-Stranded RNA Agents," issued April 7, 2020 (the "’024 Patent").

The Invention Explained

  • Problem Addressed: The patent background describes the need to improve the therapeutic properties of double-stranded RNA (dsRNA) agents used for RNA interference (RNAi), a natural process of gene silencing. Challenges include ensuring the agent's stability, potency, and minimizing off-target effects. ’024 Patent, col. 1:5-15
  • The Patented Solution: The invention provides dsRNA agents with specific, strategically placed chemical modifications. The patent claims a generalized structure, represented by Formula (I), that incorporates various types of modified nucleotides (e.g., 2'-O-alkyl, 2'-fluoro) and a "thermally destabilizing nucleotide" at a specific position to optimize the agent's gene-silencing activity and metabolic stability. ’024 Patent, abstract ’024 Patent, col. 2:2-40
  • Technical Importance: By defining specific patterns of chemical modification, the invention sought to create more effective and durable RNAi therapeutics suitable for clinical use. ’024 Patent, col. 2:5-15

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims, including claim 17 Compl. ¶33 Claim 17 depends on independent claim 1.
  • Independent Claim 1 includes the following essential elements:
    • A double-stranded RNA (dsRNA) agent capable of inhibiting the expression of a target gene.
    • The agent comprises a sense strand and an antisense strand, each having between 14 and 40 nucleotides.
    • The dsRNA agent is represented by a detailed chemical structure, Formula (I).
    • Formula (I) defines specific regions (B1, B1', B2, B2', etc.) containing particular chemical modifications from a select group (e.g., 2'-O-alkyl, 2'-halo, ENA, BNA/LNA).
    • It requires a "thermally destabilizing nucleotide" (C1) at a site opposite the seed region of the antisense strand.
    • It defines specific lengths and modification types for other nucleotide positions (T1, T1', T2, T3').
  • The complaint's reference to "one or more claims" suggests the potential to assert other dependent or independent claims later in the litigation. Compl. ¶33

U.S. Patent No. 10,208,307 - "Transthyretin (TTR) iRNA Compositions and Methods of Use Thereof for Treating or Preventing TTR-Associated Diseases"

  • Patent Identification: U.S. Patent No. 10,208,307, "Transthyretin (TTR) iRNA Compositions and Methods of Use Thereof for Treating or Preventing TTR-Associated Diseases," issued February 19, 2019 (the "’307 Patent").

The Invention Explained

  • Problem Addressed: The patent addresses transthyretin (TTR)-associated diseases, such as various forms of amyloidosis, which are caused by the aggregation and deposition of misfolded TTR protein and for which effective treatments are needed. ’307 Patent, col. 2:5-9 ’307 Patent, col. 2:60-64
  • The Patented Solution: The invention provides specific double-stranded RNAi agents designed to target and silence the TTR gene, thereby reducing the production of the TTR protein. The claims specify the exact nucleotide sequences of the sense and antisense strands, the locations of chemical modifications for stability and efficacy, and the conjugation of a ligand to aid delivery. ’307 Patent, abstract ’307 Patent, col. 3:1-12
  • Technical Importance: This technology represents a targeted, genetic-level approach to treating a class of protein-misfolding diseases by preventing the creation of the problematic protein in the first place. ’307 Patent, col. 2:60-64

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims, including claim 22 Compl. ¶58 Claim 22 is an independent claim.
  • Independent Claim 22 includes the following essential elements:
    • A double stranded ribonucleic acid (RNAi) agent.
    • A sense strand comprising the nucleotide sequence of SEQ ID NO: 9.
    • An antisense strand comprising the nucleotide sequence of SEQ ID NO: 7.
    • Specific nucleotides (a, c, g, and u) are defined as being 2'-O-methyl.
    • Specific nucleotides (Af, Cf, Gf, and Uf) are defined as being 2'-fluoro.
    • At least one internucleotide linkage is a phosphorothioate linkage.
    • The sense strand is conjugated to a ligand, wherein the ligand is L96 (N-tris(GalNAc-alkyl)-amido-decanoyl)]-4-hydroxyprolinol).
  • The complaint's reference to "one or more claims" suggests the potential to assert other claims. Compl. ¶58

U.S. Patent No. 10,683,501 - "Transthyretin (TTR) iRNA compositions and methods of use thereof for treating or preventing TTR-associated diseases"

  • Patent Identification: U.S. Patent No. 10,683,501 ("the '501 Patent"), "Transthyretin (TTR) iRNA compositions and methods of use thereof for treating or preventing TTR-associated diseases," issued June 16, 2020.
  • Technology Synopsis: The '501 Patent claims methods for prophylactically treating a human subject at risk of developing a TTR-associated disease. The method involves administering a therapeutically effective amount of a double-stranded RNAi agent with a specific structure designed to inhibit TTR expression. Compl. ¶¶74-76
  • Asserted Claims: Claim 21 (independent) is identified as an example. Compl. ¶81
  • Accused Features: The complaint alleges that Cipla’s ANDA Product contains the claimed vutrisiran agent and that its proposed labeling will instruct for its use in a manner that infringes the claimed prophylactic treatment method. Compl. ¶¶82-83

U.S. Patent No. 11,286,486 - "Transthyretin (TTR) iRNA compositions and methods of use thereof for treating or preventing TTR-associated diseases"

  • Patent Identification: U.S. Patent No. 11,286,486 ("the '486 Patent"), "Transthyretin (TTR) iRNA compositions and methods of use thereof for treating or preventing TTR-associated diseases," issued March 29, 2022.
  • Technology Synopsis: The '486 Patent claims methods for treating a subject suffering from a TTR-associated disease. The method involves administering a therapeutically effective amount of a double-stranded RNAi agent with a specific structure to inhibit TTR expression. Compl. ¶¶96-98
  • Asserted Claims: Claim 21 (independent) is identified as an example. Compl. ¶103
  • Accused Features: The complaint alleges that Cipla’s ANDA Product is the claimed vutrisiran agent and that its proposed labeling will instruct for its use in treating subjects suffering from TTR-associated diseases, thereby infringing the claimed method. Compl. ¶¶104-105

U.S. Patent No. 12,049,628 - "Transthyretin (TTR) iRNA compositions and methods of use thereof for treating or preventing TTR-associated diseases"

  • Patent Identification: U.S. Patent No. 12,049,628 ("the '628 Patent"), "Transthyretin (TTR) iRNA compositions and methods of use thereof for treating or preventing TTR-associated diseases," issued July 30, 2024.
  • Technology Synopsis: The '628 Patent is directed to a salt of a double-stranded RNAi agent that inhibits TTR expression. The claims specifically cover the salt form of the therapeutic agent, distinguishing it from the non-salt form. Compl. ¶¶118-120
  • Asserted Claims: Claim 1 (independent) is identified as an example. Compl. ¶125
  • Accused Features: The complaint alleges that Cipla’s ANDA Product is vutrisiran sodium, which is a salt of a double-stranded RNAi agent, thereby infringing the claims directed to the salt composition. Compl. ¶¶126-127

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Cipla's ANDA Product," identified as a generic version of Alnylam's AMVUTTRA® (vutrisiran) injection, 25 mg/0.5 mL Compl. ¶¶1-2 Compl. ¶23

Functionality and Market Context

  • The complaint alleges that Cipla's ANDA Product is a transthyretin-directed small interfering RNA (siRNA) therapeutic Compl. ¶22 Its active ingredient, vutrisiran, is described as a double-stranded RNAi agent comprising a sense strand and an antisense strand, with specific nucleotide sequences (SEQ ID NO: 10 and SEQ ID NO: 7, respectively), chemical modifications, and a ligand conjugate (Compl. ¶¶34-36; Compl. ¶60). The purpose of Cipla's ANDA submission is to obtain FDA approval to market this product as a generic equivalent to AMVUTTRA® before the expiration of Alnylam's patents, which is the act of infringement alleged under the Hatch-Waxman Act Compl. ¶32 The complaint includes a diagram of the general structure of the accused vutrisiran agent, represented by Formula (I) from the '024 Patent Compl. ¶36

IV. Analysis of Infringement Allegations

’024 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A double-stranded RNA (dsRNA) agent capable of inhibiting the expression of a target gene... Cipla's ANDA Product contains vutrisiran, which is a double stranded RNAi agent capable of inhibiting the expression of a target gene. ¶34 col. 311:32-34
wherein the dsRNA agent is represented by formula (I): [structure] Vutrisiran comprises a dsRNA agent that is represented by formula (I). ¶36 col. 311:40-41
wherein B1, B1', B2, B2', B3, B3', and B4' each independently represent a nucleotide containing a modification selected from the group consisting of 2'-O-alkyl, 2'-substituted alkoxy, 2'-substituted alkyl, 2'-halo, ENA, and BNA/LNA; The complaint details the specific modifications at positions along the vutrisiran sense and antisense strands, which allegedly correspond to the modifications required by the formula. ¶37 col. 311:46-52
C1 is a thermally destabilizing nucleotide... placed at a site opposite to the seed region (positions 2-8) of the antisense strand; The complaint does not provide sufficient detail for analysis of this specific element. col. 311:53-57
wherein the sense and antisense strands comprise six phosphorothioate internucleotide linkage modifications. The complaint alleges the sense and antisense strands of vutrisiran comprise six phosphorothioate internucleotide linkage modifications. ¶37 col. 314:14-17

’307 Patent Infringement Allegations

Claim Element (from Independent Claim 22) Alleged Infringing Functionality Complaint Citation Patent Citation
A double stranded ribonucleic acid (RNAi) agent comprising a sense strand and an antisense strand, wherein the sense strand comprises the nucleotide sequence 5'-usgsggaauUfCfAfUfguanaaccaga-3' (SEQ ID NO: 9) and the antisense strand comprises the nucleotide sequence 5'-usCfsuungGfUfUfancAfcaUfAaucecsu-3' (SEQ ID NO: 7); According to Cipla's Notice Letter, Cipla's ANDA Product contains vutrisiran, a double stranded RNAi agent. The sense strand comprises the nucleotide sequence 5'-usgsggaauUfCfAfUfguanaaccagaL96-3' (SEQ ID NO: 10) and the antisense strand comprises the nucleotide sequence 5'-usCfsuungGfUfUfancAfcaUfAaucecsu-3' (SEQ ID NO: 7). ¶59; ¶60 col. 233:1-7
wherein a, c, g, and u are 2'-O-methyl (2'-OMe) A, C, G, and U... and Af, Cf, Gf, and Uf are 2'-fluoro A, C, G, and U... The allegedly infringing vutrisiran contains the specified 2'-O-methyl and 2'-fluoro modifications. ¶60 col. 233:8-10
and wherein at least one internucleotide linkage is a phosphorothioate linkage; The allegedly infringing vutrisiran contains a phosphorothioate linkage. ¶60 col. 233:11-12
and wherein the sense strand is conjugated to a ligand, wherein the ligand is L96... The allegedly infringing vutrisiran contains the specified L96 ligand. ¶60 col. 233:12-14

Identified Points of Contention

  • Scope Questions: The complaint alleges that Cipla did not contest infringement of many asserted claims in its Notice Letter, instead focusing on invalidity Compl. ¶38 Compl. ¶61 Compl. ¶128 This suggests that the primary dispute may not be over claim scope or the structural identity of the accused product, but rather over the validity of the patents themselves. The court will still need to confirm that the vutrisiran sodium product falls within the scope of the claims.
  • Technical Questions: For the '024 Patent, a technical question is whether the specific structure of vutrisiran meets every limitation of the generalized Formula (I), including the functional requirement for a "thermally destabilizing nucleotide" (C1). For the '307, '501, '486, and '628 patents, the allegations appear to map the specific structure of vutrisiran directly onto the claimed sequences and modifications, suggesting a more straightforward infringement analysis that may depend heavily on the accuracy of the information in Cipla's ANDA filing.

V. Key Claim Terms for Construction

  • The Term: "thermally destabilizing nucleotide" (’024 Patent, Claim 1)

    • Context and Importance: This term is a central structural feature of the invention claimed in the '024 Patent, appearing as element "C1" in the core Formula (I). The definition of what constitutes such a nucleotide is critical for determining the scope of the claim. Practitioners may focus on this term because its interpretation will dictate whether a range of modified RNA agents, including potentially the accused product, fall within the patent's coverage.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification states that a thermally destabilizing modification can be, for example, "a nucleotide that forms a mismatch pair with the opposing nucleotide in the antisense strand, ii) a nucleotide having an abasic modification, and iii) a nucleotide having a sugar modification." ’024 Patent, col. 41:10-14 This list of examples may support an interpretation covering any modification that achieves the functional outcome of thermal destabilization.
      • Evidence for a Narrower Interpretation: The specification also describes specific embodiments and provides examples of particular destabilizing modifications. A party could argue that the term should be limited to these disclosed examples, such as a G:A, C:A, U:A, or A:A mismatch, or specific abasic nucleotides. ’024 Patent, col. 49:60-50:23

  • The Term: "a salt of a double stranded ribonucleic acid (RNAi) agent" ’628 Patent, Claim 1

    • Context and Importance: This term is the subject of the '628 Patent. The dispute will hinge on whether Cipla's product, identified as "vutrisiran sodium," constitutes a "salt" as contemplated by the patent. This is fundamental to infringement of the '628 patent.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent does not appear to provide an explicit definition of "salt" beyond its common chemical meaning. A party may argue for the plain and ordinary meaning, which would encompass any compound formed by the reaction of an acid with a base, such as the sodium salt of an RNAi agent.
      • Evidence for a Narrower Interpretation: Dependent claim 8 specifies a "sodium salt" ’628 Patent, claim 8 A defendant might argue that the scope of "salt" in claim 1 should be interpreted in light of the overall disclosure, which focuses heavily on pharmaceutically acceptable salts, potentially raising questions if the accused product's salt form has characteristics not fully described. However, the complaint's identification of the accused product as "vutrisiran sodium" suggests a direct read on at least claim 8. Compl. ¶127

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement of infringement for the method claims of the '501 and '486 patents. It asserts that Cipla knows of the patents and that its proposed product labeling will instruct, encourage, and promote the administration of its ANDA product in a manner that directly infringes these method claims. Compl. ¶40 Compl. ¶63 Compl. ¶85 Compl. ¶107
  • Willful Infringement: The complaint alleges that Cipla has known of the patents-in-suit since at least the date of its Notice Letter (August 3, 2026). It further alleges that Cipla's continued intent to manufacture and sell its ANDA product, despite this knowledge, constitutes willful infringement, which may warrant enhanced damages. (Compl. ¶¶15; ¶42; ¶65; ¶87; ¶109; ¶132)

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

  1. A central issue will be one of patent validity: The complaint repeatedly notes that Cipla’s Paragraph IV certification did not contest infringement for many claims on any basis other than the alleged invalidity or unenforceability of the patents. This procedural posture suggests that the core of the litigation will likely focus on Cipla's attempts to invalidate Alnylam's patents based on arguments such as anticipation, obviousness, or lack of enablement, rather than on disputes over whether the accused product's structure meets the claim limitations.

  2. A secondary issue is one of definitional precision in chemical structure: While infringement appears to be conceded for some claims, the case will ultimately depend on whether the chemical composition of Cipla's "vutrisiran sodium" product, as detailed in its ANDA, aligns precisely with the complex structural and functional limitations of the asserted claims. This includes not only the exact nucleotide sequences but also the specific types and locations of chemical modifications, the nature of the conjugated ligand, and, for the '628 patent, its existence as a "salt."

  3. A further question relates to the scope of method claims: For the '501 and '486 patents, the dispute will extend beyond the composition of the drug itself to the methods of its use. The key question will be whether Cipla's proposed product label will inevitably lead physicians and patients to perform the patented methods of either prophylactically treating subjects at risk ('501 Patent) or treating subjects already suffering from the disease ('486 Patent).