BioMarin Pharmaceutical Inc v. Zydus Lifesciences Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: BioMarin Pharmaceutical Inc. (Delaware)
  • Defendant: Zydus Lifesciences Limited (India); Zydus Lifesciences Global FZE (Dubai); Zydus Pharmaceuticals (USA) Inc. (New Jersey)
  • Plaintiff’s Counsel: FBT Gibbons LLP
• Case Identification: BioMarin Pharmaceutical Inc. v. Zydus Lifesciences Limited, 1:26-cv-01005, D.N.J., 02/02/2026
• Venue Allegations: Venue is alleged to be proper as to Defendant Zydus USA because it is organized under New Jersey law and has a regular and established place of business in the district. Venue is alleged to be proper as to the foreign defendants, Zydus Ltd. and Zydus FZE, on the basis that foreign entities may be sued in any judicial district.
• Core Dispute: Plaintiff alleges that Defendants’ submission of an Abbreviated New Drug Application (ANDA) to market a generic version of Plaintiff's drug VOXZOGO® constitutes an act of patent infringement under the Hatch-Waxman Act.
• Technical Context: The technology involves methods of using C-type natriuretic peptide (CNP) variants to treat certain forms of skeletal dysplasia, such as achondroplasia (the most common type of dwarfism), in very young children.
• Key Procedural History: This action was initiated under the Hatch-Waxman Act following Defendants' submission of ANDA No. 220670 seeking FDA approval to market a generic version of BioMarin's VOXZOGO® drug. The ANDA included a Paragraph IV certification against the patent-in-suit, asserting that the patent is invalid, unenforceable, or will not be infringed by the generic product. The complaint states it was filed within the 45-day period following receipt of Defendants' notice letter, which triggers an automatic 30-month stay on FDA approval of the ANDA. The complaint also notes that Defendants filed Paragraph III certifications for other Orange Book-listed patents, indicating they will not launch their generic product until those patents expire, with the latest-expiring patent having a term extension until June 11, 2035.

Case Timeline

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

U.S. Patent No. 12,233,106 - "C-Type Natriuretic Peptide Variants to Treat Skeletal Dysplasia in Children"

• Patent Identification: U.S. Patent No. 12,233,106, "C-Type Natriuretic Peptide Variants to Treat Skeletal Dysplasia in Children", issued February 12, 2025.

The Invention Explained

• Problem Addressed: The patent's background describes how certain genetic mutations, particularly in the fibroblast growth factor receptor 3 (FGFR-3), cause skeletal dysplasias like achondroplasia by disrupting normal cartilage and bone growth '106 Patent, col. 1:48-55 While C-type natriuretic peptide (CNP) can counteract this effect, its therapeutic use is limited by a very short plasma half-life of only a few minutes, requiring continuous infusion to be effective '106 Patent, col. 3:20-29
• The Patented Solution: The invention provides methods for treating skeletal dysplasias specifically in very young children—from birth to about two years old—by administering specifically defined CNP variants '106 Patent, abstract '106 Patent, col. 4:1-4 These methods are intended to improve growth velocity and other symptoms of skeletal dysplasia by using CNP variants that may have improved therapeutic properties compared to naturally occurring CNP '106 Patent, col. 3:29-33
• Technical Importance: The patented method provides a therapeutic strategy for achondroplasia and other skeletal dysplasias targeted at a critical developmental window in infants and toddlers, a patient population not explicitly addressed by prior therapeutic approaches '106 Patent, col. 3:49-55 Compl. ¶35

Key Claims at a Glance

• The complaint asserts infringement of one or more claims, including at least claim 1 of the '106 patent Compl. ¶50
• The essential elements of independent claim 1 are:
  • A method of treating skeletal dysplasia
  • in a subject about 0 month to about 2 years old
  • comprising administering to the subject a composition
  • comprising a C-type natriuretic peptide (CNP) variant
  • in an amount effective to treat the skeletal dysplasia,
  • wherein the CNP variant is selected from a specified group of peptide sequences listed in the claim.
• The complaint notes that Defendants' notice letter did not contest infringement of claims 1-14, and reserves the right to assert additional claims Compl. ¶51

III. The Accused Instrumentality

Product Identification

• The accused instrumentality is the "Zydus ANDA Product," identified as a generic version of VOXZOGO® (vosoritide for injection) in dosages of 0.4 mg/vial, 0.56 mg/vial, and 1.2 mg/vial, for which Defendants have sought FDA approval via ANDA No. 220670 Compl. ¶¶1, 7, 46

Functionality and Market Context

• The complaint alleges that the Zydus ANDA Product is a generic version of BioMarin’s VOXZOGO®, which was the first drug to receive regulatory approval in the United States for the treatment of achondroplasia Compl. ¶¶1, 37 The infringement allegation is based on the intended use of the Zydus ANDA product, which the complaint claims is for treating skeletal dysplasia in children from birth to about two years of age, a use covered by the '106 patent Compl. ¶50 The complaint alleges that the label for the Zydus ANDA Product will instruct users to perform the patented method Compl. ¶55 No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'106 Patent Infringement Allegations

• Identified Points of Contention:
  • Procedural Question: The complaint alleges that Defendants "conceded infringement" by failing to provide a detailed, claim-by-claim analysis for their non-infringement position in their Paragraph IV notice letter, as required by FDA regulations Compl. ¶51 A central question for the court will be what legal effect, if any, this alleged deficiency has on Defendants' ability to contest infringement in the litigation.
  • Validity Questions: While the complaint focuses on infringement, the core of a Hatch-Waxman defense often rests on invalidity. The dispute will likely involve questions of whether the asserted claims, particularly the limitation to subjects "about 0 month to about 2 years old," are valid over the prior art. Defendants may argue that applying CNP variants to a younger population was obvious or that the patent lacks sufficient written description or enablement for this specific age group.

V. Key Claim Terms for Construction

• The Term: "a subject about 0 month to about 2 years old"
• Context and Importance: This phrase is the central limitation defining the scope of the patented method and is critical for distinguishing the invention from potential prior art that may have disclosed similar treatments in older subjects. Practitioners may focus on this term because the patentability of the claims could depend on the novelty and non-obviousness of applying this therapy to this specific, very young patient population. The definition of "about" will determine the precise boundaries of the claimed age range.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: Parties arguing for a broader definition may point to the patent's use of the word "about," which suggests the age range is not intended to be a rigid, absolute limit '106 Patent, col. 63:20 The specification also uses flexible language, such as "less than or about 2 years old" '106 Patent, col. 4:1-2, which may support an interpretation that includes subjects slightly outside a strict 24-month cutoff.
  • Evidence for a Narrower Interpretation: Parties arguing for a narrower definition may cite the patent's repeated and specific focus on this age group as the core of the invention '106 Patent, abstract '106 Patent, col. 3:52-53 The patent also describes clinical trial data segmented into specific cohorts, such as "Ages 0 to <6 months" and "Ages 6 to <24 months" '106 Patent, Fig. 2, which a party could use to argue that the term "about 2 years old" was intended to mean up to, but not including, the 24-month mark.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendants will knowingly and intentionally provide a product label with instructions for administering the Zydus ANDA Product in a manner that directly infringes the '106 patent Compl. ¶55 The complaint also alleges contributory infringement, stating the Zydus ANDA Product is especially adapted for an infringing use and has no substantial non-infringing use Compl. ¶56
• Willful Infringement: The complaint includes a prayer for a judgment that Defendants willfully infringed Compl. prayer (g) The factual basis for this allegation is Defendants' pre-suit knowledge of the '106 patent, which is evidenced by their submission of a Paragraph IV certification specifically targeting the patent Compl. ¶53

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

• A central threshold issue will be one of procedural effect: does the alleged failure by Zydus to provide a detailed non-infringement analysis in its Paragraph IV notice, as claimed by BioMarin, constitute a concession of infringement or otherwise bar Zydus from litigating that issue?
• A second key question will be one of patent validity: assuming infringement is found, can Zydus establish by clear and convincing evidence that treating skeletal dysplasia with a known class of compounds (CNP variants) in the specific age group of "about 0 month to about 2 years old" was obvious or lacked adequate written description at the time of the invention?