DCT

1:26-cv-00735

Biogen Ma Inc v. Somerset Therap LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:26-cv-00735, D. Del., 06/22/2026
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because several of the Somerset Defendants are organized under the laws of Delaware and maintain registered agents there, thereby residing in the district.
  • Core Dispute: Plaintiffs allege that Defendants' submission of an Abbreviated New Drug Application (ANDA) for a generic version of the drug Spinraza® (nusinersen) constitutes an act of infringement of three U.S. patents covering the drug's composition and methods of use for treating spinal muscular atrophy (SMA).
  • Technical Context: The technology involves antisense oligonucleotides designed to modulate the splicing of the SMN2 gene, thereby increasing the production of functional SMN protein to treat the neurodegenerative disease spinal muscular atrophy.
  • Key Procedural History: This lawsuit is the second action filed by Plaintiffs against Defendants concerning the same ANDA. A prior suit alleged infringement of three different patents. This current action was filed in response to Defendants' "Second Notice Letter," which contained Paragraph IV certifications against the three patents-in-suit, asserting they are invalid, unenforceable, or will not be infringed by the proposed generic product.

Case Timeline

Date Event
2005-06-23 Earliest Priority Date for '977 Patent
2009-06-17 Earliest Priority Date for '853 Patent
2009-06-17 Earliest Priority Date for '750 Patent
2013-01-29 '977 Patent Issued
2015-03-17 '853 Patent Issued
2017-08-01 '750 Patent Issued
2026-04-10 Plaintiffs received Somerset's First Notice Letter for ANDA
2026-05-29 Date of Somerset's Second Notice Letter
2026-06-22 Complaint Filing Date

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

U.S. Patent No. 8,361,977 - "Compositions and methods for modulation of SMN2 splicing"

  • Patent Identification: U.S. Patent No. 8,361,977, titled "Compositions and methods for modulation of SMN2 splicing," issued on January 29, 2013 Compl. ¶29

The Invention Explained

  • Problem Addressed: The patent addresses spinal muscular atrophy (SMA), a neurodegenerative disorder caused by the loss of the SMN1 gene. A nearly identical gene, SMN2, cannot fully compensate because a silent mutation results in the inefficient inclusion of a critical segment (exon 7) in its messenger RNA (mRNA), leading to a non-functional protein '977 Patent, col. 2:24-48
  • The Patented Solution: The invention provides antisense compounds, which are short, synthetic nucleic acid chains, designed to bind to specific sites on the SMN2 pre-mRNA. This binding modulates the splicing process to increase the inclusion of exon 7, thereby promoting the production of a full-length, functional SMN protein from the SMN2 gene '977 Patent, abstract '977 Patent, col. 3:5-13
  • Technical Importance: This technology offers a therapeutic strategy for SMA by correcting the genetic defect at the RNA level, using the patient's own SMN2 gene as a template to produce the protein that is otherwise missing '977 Patent, col. 4:50-65

Key Claims at a Glance

  • The complaint asserts independent claim 19 Compl. ¶48
  • The essential elements of independent claim 19 are:
    • An antisense oligonucleotide having a nucleotide sequence 100% complementary to a target region of SEQ ID NO: 1.
    • The 5'-most nucleotide of the target region is nucleotide 124 of SEQ ID NO: 1.
    • The antisense oligonucleotide is 12 to 20 nucleotides in length.
    • Each nucleoside of the antisense oligonucleotide comprises a 2'-O-methoxyethyl sugar modification.
  • The complaint does not explicitly reserve the right to assert dependent claims but alleges infringement of "one or more of the claims" Compl. ¶49

U.S. Patent No. 8,980,853 - "Compositions and methods for modulation of SMN2 splicing in a subject"

  • Patent Identification: U.S. Patent No. 8,980,853, titled "Compositions and methods for modulation of SMN2 splicing in a subject," issued on March 17, 2015 Compl. ¶33

The Invention Explained

  • Problem Addressed: The patent addresses the need for effective treatment of SMA, particularly severe, infantile-onset forms of the disease, by correcting the SMN2 splicing defect in a patient '853 Patent, col. 2:1-15
  • The Patented Solution: The invention claims a specific method of treating SMA by administering a precisely defined antisense oligonucleotide directly into the intrathecal space (the fluid-filled space around the spinal cord) of a subject via a bolus injection. This delivery route is intended to effectively target the neurons of the central nervous system affected by SMA '853 Patent, abstract '853 Patent, col. 3:1-4
  • Technical Importance: The claimed method specifies a direct and clinically relevant route of administration (intrathecal injection) necessary to deliver the therapeutic oligonucleotide to the central nervous system, bypassing the blood-brain barrier which typically prevents drugs from reaching the brain and spinal cord '853 Patent, col. 3:45-52

Key Claims at a Glance

  • The complaint asserts independent claim 1 Compl. ¶61
  • The essential elements of independent claim 1 are:
    • A method comprising administering by a bolus injection into the intrathecal space of a subject with infantile-onset type I spinal muscular atrophy (SMA).
    • An antisense compound comprising an antisense oligonucleotide consisting of 18 linked nucleosides.
    • The oligonucleotide has a nucleobase sequence consisting of the nucleobase sequence SEQ ID NO: 1.
    • Each internucleoside linkage of the oligonucleotide is a phosphorothioate linkage.
    • Each nucleoside of the oligonucleotide is a 2'-MOE nucleoside.
    • The administering of the antisense compound ameliorates at least one symptom of SMA in the subject.
  • The complaint does not explicitly reserve the right to assert dependent claims but alleges infringement of "one or more of the claims" Compl. ¶62

U.S. Patent No. 9,717,750 - "Compositions and methods for modulation of SMN2 splicing in a subject"

  • Patent Identification: U.S. Patent No. 9,717,750, titled "Compositions and methods for modulation of SMN2 splicing in a subject," issued on August 1, 2017 Compl. ¶37
  • Technology Synopsis: The patent claims a method of treating a human subject having type II SMA by administering a specific 18-nucleoside antisense oligonucleotide via bolus injection into the intrathecal space '750 Patent, abstract '750 Patent, claim 1 The method is intended to ameliorate symptoms of SMA by correcting the splicing of the SMN2 gene '750 Patent, claim 1
  • Asserted Claims: The complaint asserts at least independent claim 1 Compl. ¶75
  • Accused Features: The complaint alleges that the use of Somerset's Proposed ANDA Product, in accordance with its proposed label, will infringe the patent Compl. ¶76 Compl. ¶77

III. The Accused Instrumentality

  • Product Identification: The accused instrumentality is "Somerset's Proposed ANDA Product," identified as a generic version of Spinraza® (nusinersen) intrathecal injection, 12 mg/5 mL, for which Defendants seek FDA approval under ANDA No. 221418 Compl. ¶1
  • Functionality and Market Context: The complaint alleges that the active ingredient in the proposed product is nusinersen Compl. ¶44, an antisense oligonucleotide designed to treat spinal muscular atrophy (SMA) Compl. ¶26 The product is intended to be administered by healthcare professionals as an intrathecal injection Compl. ¶1 Compl. ¶46 The complaint alleges that the product's proposed label will be "substantially identical" to the label for the branded drug Spinraza® and will instruct for its administration in a manner that infringes the asserted patents Compl. ¶46 If approved, the product would be marketed as a generic competitor to Spinraza® Compl. ¶¶1-2

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'977 Patent Infringement Allegations

Claim Element (from Independent Claim 19) Alleged Infringing Functionality Complaint Citation Patent Citation
[A]n antisense oligonucleotide having a nucleotide sequence 100% complementary to a target region of SEQ ID NO: 1... The accused product is alleged to be or contain nusinersen, an antisense oligonucleotide designed to be complementary to a target region in the SMN2 pre-mRNA. ¶44; ¶48; ¶49 col. 63:62-65
wherein: the 5'-most nucleotide of the target region is nucleotide 124 of SEQ ID NO: 1; The nusinersen in the accused product is alleged to target this specific nucleotide position within the SMN2 pre-mRNA. ¶44; ¶48; ¶49 col. 64:14-16
the antisense oligonucleotide is 12 to 20 nucleotides in length; The nusinersen in the accused product is alleged to have a length that falls within this range. ¶44; ¶48; ¶49 col. 64:17-18
and each nucleoside of the antisense oligonucleotide comprises a 2'-O-methoxyethyl sugar modification. The nusinersen in the accused product is alleged to contain this specific chemical modification at each nucleoside. ¶44; ¶48; ¶49 col. 64:19-21

'853 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
[A] method comprising administering by a bolus injection into the intrathecal space of a subject with infantile-onset type I spinal muscular atrophy (SMA) The proposed product label is alleged to instruct administration by intrathecal injection to patients with SMA. ¶46; ¶61; ¶63 col. 55:1-11
an antisense compound comprising an antisense oligonucleotide consisting of 18 linked nucleosides, wherein the oligonucleotide has a nucleobase sequence consisting of the nucleobase sequence SEQ ID NO: 1... The accused product is alleged to be nusinersen, which is an 18-nucleoside antisense oligonucleotide with this specific sequence. ¶44; ¶61; ¶62 col. 55:7-11
wherein each internucleoside linkage of the oligonucleotide is a phosphorothioate linkage, wherein each nucleoside of the oligonucleotide is a 2'-MOE nucleoside, The nusinersen in the accused product is alleged to contain these specific chemical structures (phosphorothioate linkages and 2'-MOE sugar modifications). ¶44; ¶61; ¶62 col. 55:11-15
and wherein the administering of the antisense compound ameliorates at least one symptom of SMA in the subject. The proposed label is alleged to instruct a method of use that results in the therapeutic benefit of ameliorating SMA symptoms. ¶46; ¶61; ¶63 col. 55:15-17
  • Identified Points of Contention:
    • Scope Questions: For the '853 and '750 patents, which claim methods of treating specific patient populations (e.g., "type I SMA" or "type II SMA"), a central question may be whether the instructions on the defendant's proposed label will direct use in a way that falls squarely within the scope of these claimed patient groups.
    • Technical Questions: For the '977 patent, which claims a specific chemical composition, the dispute will likely focus on whether the defendant's proposed product is chemically and structurally identical to the claimed oligonucleotide. For the method patents ('853 and '750), a question of fact may arise regarding whether administration according to the proposed label necessarily results in the functional outcome of "ameliorat[ing] at least one symptom of SMA," as required by the claims.

V. Key Claim Terms for Construction

The complaint does not provide sufficient detail to identify specific claim terms that are definitively in dispute. However, based on the nature of the claims, certain terms are likely to be a focus of litigation.

Term 1 (from '853 Patent, Claim 1)

  • The Term: "ameliorates at least one symptom of SMA in the subject"
  • Context and Importance: This functional language is a required step of the method claim. Practitioners may focus on this term because Defendants could argue it is indefinite under 35 U.S.C. § 112 for failing to specify what degree of amelioration is required, or they may argue that their product's label does not guarantee this outcome for every patient, thereby avoiding inducement of infringement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes a wide range of potential benefits, stating the methods can result in "improved motor function," "delayed or reduced loss of motor function," "improved respiratory function," or "improved survival" '853 Patent, col. 5:35-43 This could support an interpretation where achieving any of these constitutes "amelioration."
    • Evidence for a Narrower Interpretation: Defendants might point to specific clinical trial data or examples in the patent to argue that the term requires a specific, statistically significant level of improvement in a validated clinical endpoint, rather than any subjective or minor improvement.

Term 2 (from '853 Patent, Claim 1)

  • The Term: "subject with infantile-onset type I spinal muscular atrophy (SMA)"
  • Context and Importance: This term defines the specific patient population for the claimed method. Its construction is critical because infringement will depend on whether the defendant's proposed label instructs administration to this exact group. A mismatch between the claim's definition and the label's indication could be a basis for a non-infringement argument.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: Plaintiffs may argue the term should be given its plain and ordinary meaning as understood by a person of ordinary skill in the medical field at the time of the invention.
    • Evidence for a Narrower Interpretation: The patent's background section provides a specific clinical description of SMA types, noting that "Type I SMA is the most severe form with onset at birth or within 6 months and typically results in death within 2 years" and that such children "are unable to sit or walk" '853 Patent, col. 2:5-10 A defendant may argue that the claim is limited to patients meeting this narrow, severe definition.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Defendants will induce infringement of the method claims ('853 and '750 patents) by creating a product label that will instruct healthcare professionals to administer the accused product in a manner that directly infringes those claims Compl. ¶56 Compl. ¶70 Compl. ¶84 The complaint further alleges contributory infringement, stating the accused product is especially made for an infringing use and is not suitable for substantial noninfringing use Compl. ¶57 Compl. ¶71 Compl. ¶85
  • Willful Infringement: The complaint does not contain a formal count for willful infringement. However, it lays the factual groundwork for such a claim by alleging that Defendants had knowledge of the asserted patents at least due to their listing in the FDA's Orange Book and their inclusion in the "Second Notice Letter" sent to Plaintiffs Compl. ¶55 Compl. ¶69 Compl. ¶83 The prayer for relief requests a finding of an exceptional case and an award of attorneys' fees Compl., prayer (f)

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

  1. A central issue will be one of structural and chemical identity: Does the Defendants' proposed generic nusinersen product fall within the precise structural definition of the composition claimed in the '977 patent, including its sequence, length, and specific chemical modifications?
  2. A second key issue will be one of induced infringement by label: Will the language of the Defendants' proposed product label-which is alleged to be substantially identical to the Spinraza® label-be found to actively encourage or instruct healthcare professionals to perform every step of the methods claimed in the '853 and '750 patents, particularly with respect to administration to the specific SMA patient subtypes recited in the claims?
  3. A third question will involve claim construction: How will the court define the scope of functional and patient-population limitations in the method claims, such as "ameliorates at least one symptom of SMA" and "infantile-onset type I spinal muscular atrophy," and will the defendant's proposed indication for use fall within those definitions?
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