DCT

2:26-cv-00556

Chemocentryx Inc v. Zydus Pharmaceuticals USA Inc

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:26-cv-00556, D.N.J., 01/16/2026
  • Venue Allegations: Venue is alleged to be proper in the District of New Jersey because Defendant Zydus USA has its headquarters and a regular and established place of business in the district, and because the foreign defendants may be sued in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to the FDA, seeking to market a generic version of Plaintiff's TAVNEOS® (avacopan) drug, constitutes an act of patent infringement under the Hatch-Waxman Act.
  • Technical Context: The dispute centers on pharmaceutical patents for avacopan, a complement 5a receptor antagonist, involving both a specific formulation to improve drug solubility and a particular solid-state "amorphous" form of the active ingredient.
  • Key Procedural History: The litigation was triggered by Defendants' submission of ANDA No. 221070 and a corresponding "Paragraph IV Certification." This certification alleges that the patents-in-suit are invalid, unenforceable, or will not be infringed by the proposed generic product, which serves as the statutory basis for this infringement action prior to any commercial sale.

Case Timeline

Date Event
2018-11-30 Earliest Priority Date ('’214 Patent)
2019-11-08 Earliest Priority Date ('’356 Patent)
2021-10-07 FDA Approval to Market TAVNEOS®
2023-03-14 ’356 Patent Issued
2024-04-09 ’214 Patent Issued
2025-12-03 Zydus Notice Letter Dated
2026-01-16 Complaint Filing Date

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

U.S. Patent No. 11,951,214 - *"Capsule formulations"*

The Invention Explained

  • Problem Addressed: The patent describes its active ingredient, avacopan ("Compound 1"), as belonging to Class II of the Biopharmaceutics Classification System (BCS), meaning it has high permeability but poor solubility in the aqueous environment of the gastrointestinal tract, which makes creating a bioavailable oral formulation challenging (Compl., Ex. A, ’214 Patent, col. 1:49-54).
  • The Patented Solution: The invention is a "solid solution capsule formulation" that dissolves or disperses avacopan in a specific vehicle. This vehicle comprises at least one non-ionic surfactant (e.g., macrogol-40-glycerol hydroxystearate) and at least one water-soluble solubilizer (e.g., polyethylene glycol 4000), which allows the poorly soluble drug to form a microemulsion or nanoemulsion in the gut, thereby improving its absorption (’214 Patent, Abstract; col. 9:1-12).
  • Technical Importance: This "self-emulsifying" or "self-solubilizing" system is a common and important pharmaceutical strategy for enhancing the oral bioavailability of poorly water-soluble drugs, potentially allowing for more consistent patient dosing and therapeutic effect (’214 Patent, col. 9:43-50).

Key Claims at a Glance

  • Independent claim 1 is asserted in the complaint (Compl. ¶54).
  • Claim 1 elements include:
    • A solid solution capsule formulation comprising avacopan.
    • A vehicle comprising at least one non-ionic surfactant selected from a specific group (macrogol-40-glycerol hydroxystearate, macrogolglycerol ricinoleate, and macrogol-15-hydroxystearate).
    • The vehicle also comprises at least one water-soluble solubilizer selected from a specific group of polyethylene glycols (PEGs).
    • Avacopan comprises about 1 to 3% by weight of the total fill weight.
    • The vehicle comprises about 97 to 99% by weight of the total fill weight.
    • The total weight of the vehicle comprises a 45:55 to 55:45 ratio of the non-ionic surfactant to the water-soluble solubilizer.
  • The complaint does not explicitly reserve the right to assert other claims, but alleges infringement of "one or more claims" (Compl. ¶55).

U.S. Patent No. 11,603,356 - *"Amorphous form of a complement component C5a receptor"*

The Invention Explained

  • Problem Addressed: As with the ’214 patent, the background highlights the challenge of delivering avacopan due to its poor solubility, which can hinder the preparation of bioavailable formulations (Compl., Ex. B, ’356 Patent, col. 2:50-55).
  • The Patented Solution: The patent discloses a specific solid form of avacopan: an "amorphous form." Unlike crystalline forms, which have an ordered, repeating molecular lattice, an amorphous form lacks long-range order. This disordered state often leads to higher solubility and dissolution rates (’356 Patent, col. 5:11-15). The invention is defined by its characteristic X-ray powder diffraction (XRPD) pattern, which has "no distinct peaks," a hallmark of an amorphous solid (’356 Patent, col. 6:60-65; Fig. 2).
  • Technical Importance: The patent notes that while many amorphous materials are highly hygroscopic (readily absorb moisture) and unstable, the claimed amorphous form of avacopan surprisingly exhibits low hygroscopicity and physical stability, making it suitable for pharmaceutical development (’356 Patent, col. 4:40-49).

Key Claims at a Glance

  • Independent claims 1 and 21 are asserted in the complaint (Compl. ¶81, ¶84).
  • Claim 1 elements include:
    • An amorphous form of [avacopan].
    • characterized by an X-ray powder diffraction pattern having no distinct peaks.
    • which is substantially free of other forms of [avacopan].
  • Claim 21 is a method of treatment claim which the complaint does not quote. The complaint alleges infringement of "at least claim 1 and/or claim 21" (Compl. ¶84).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendants' proposed generic avacopan capsules, 10 mg, as detailed in ANDA No. 221070 ("Zydus's ANDA Product") (Compl. ¶1, ¶4).

Functionality and Market Context

The complaint alleges that Zydus's ANDA Product is a generic version of ChemoCentryx's TAVNEOS® drug product (Compl. ¶1). It is alleged to contain the same active ingredient (avacopan), be administered by the same method, and have the same dosage form and amount as TAVNEOS® (Compl. ¶46). The product is intended for use as an adjunctive treatment for ANCA-associated vasculitis, mirroring the approved indication for TAVNEOS® (Compl. ¶48). The product's market positioning is as a lower-cost generic alternative intended to launch before the expiration of the patents-in-suit (Compl. ¶1).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’214 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A solid solution capsule formulation comprising [avacopan]... The Zydus ANDA Product is alleged to be a solid solution capsule formulation containing avacopan. ¶55 col. 33:57-58
...and a vehicle comprising at least one non-ionic surfactant selected from the group consisting of macrogol-40-glycerol hydroxystearate, macrogolglycerol ricinoleate, and macrogol-15-hydroxystearate... The Zydus ANDA Product is alleged to contain a vehicle with at least one of the specified non-ionic surfactants. ¶55 col. 34:1-5
...and at least one water-soluble solubilizer selected from the group consisting of PEG-1500, PEG-1540, PEG-2000, PEG-3000, PEG-3350, PEG-4000, PEG-6000, PEG-8000... The Zydus ANDA Product is alleged to contain a vehicle with at least one of the specified water-soluble solubilizers. ¶55 col. 34:6-10
...wherein [avacopan] comprises about 1 to 3% by weight of the total fill weight... The Zydus ANDA Product is alleged to contain avacopan within the specified weight percentage range. ¶55 col. 34:11-13
...the vehicle comprises about 97 to 99% by weight of the total fill weight... The vehicle in the Zydus ANDA Product is alleged to fall within the specified weight percentage range. ¶55 col. 34:13-15
...and the total weight of the vehicle comprises a 45:55 to 55:45 ratio of the at least one non-ionic surfactant to the at least one water-soluble solubilizer. The vehicle in the Zydus ANDA Product is alleged to have components in the specified ratio. ¶55 col. 34:16-19
  • Identified Points of Contention:
    • Scope Questions: The complaint's allegations are made "upon information and belief" and mirror the claim language. The central dispute will be whether the specific, confidential formulation disclosed in Zydus's ANDA actually meets every recited limitation, including the component selections, the weight percentages, and, critically, the 45:55 to 55:45 ratio of surfactant to solubilizer.
    • Technical Questions: A key question will be whether Zydus’s formulation is properly characterized as a "solid solution." Discovery will be required to determine the physical state of avacopan within the Zydus product's excipient matrix and whether it aligns with the patent's description.

’356 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An amorphous form of [avacopan]... The Zydus ANDA Product is alleged to contain an amorphous form of avacopan. ¶82 col. 28:46
...characterized by an X-ray powder diffraction pattern having no distinct peaks... The amorphous form of avacopan in the Zydus ANDA Product is alleged to be characterized by an XRPD pattern with no distinct peaks. ¶82 col. 28:60-61
...which is substantially free of other forms of [avacopan]. The amorphous form of avacopan in the Zydus ANDA Product is alleged to be substantially free of other (e.g., crystalline) forms of avacopan. ¶82 col. 28:62-63
  • Identified Points of Contention:
    • Scope Questions: The term "no distinct peaks" is qualitative. The dispute may center on the degree to which any observed features in the XRPD pattern of Zydus's product constitute "distinct peaks" versus background noise or a weak amorphous "halo." The definition of "substantially free" will also be critical, as Zydus may argue its product contains a level of crystalline material that falls outside this scope.
    • Technical Questions: The primary technical question will be one of physical characterization. What does analytical testing (e.g., XRPD, DSC, SEM) of Zydus’s actual ANDA product reveal about the solid-state form of the avacopan active ingredient? Does it match the characteristics claimed in the patent?

V. Key Claim Terms for Construction

  • The Term: "solid solution capsule formulation" (’214 Patent, Claim 1)
  • Context and Importance: This term defines the overall nature of the claimed invention. The infringement analysis will depend on whether Zydus's product, which contains avacopan mixed with excipients, qualifies as a "solid solution." Practitioners may focus on this term because Zydus could argue its formulation is a different type of mixture, such as a simple dispersion or suspension, that falls outside the claim scope.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification states that the drug substance can be "dissolved or dispersed in an excipient matrix" (’214 Patent, col. 7:7-9), which may support a construction that does not require complete molecular-level dissolution.
    • Evidence for a Narrower Interpretation: The patent also describes the drug as "completely and molecularly dissolved" and appearing as a "uniform solid solution to the naked eye" (’214 Patent, col. 6:1-5). This language could support a narrower construction requiring a true homogenous, single-phase solution.
  • The Term: "substantially free of other forms" (’356 Patent, Claim 1)
  • Context and Importance: This term sets the purity standard for the claimed amorphous form. The case may turn on the level of crystalline avacopan present in Zydus's product. If Zydus's product contains more than the defined threshold of crystalline material, it would not infringe.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party might argue that "substantially" is a flexible term of degree that depends on context, potentially allowing for more than the specification's explicit numerical limit.
    • Evidence for a Narrower Interpretation: The specification provides an explicit definition: "'Substantially free' refers to an amount of 10% or less of another form, preferably 8%, 5%, 4%, 3%, 2%, 1%, 0.5%, or less of another form" (’356 Patent, col. 5:17-20). This provides strong evidence for a clear numerical cutoff at 10%.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement of infringement based on Defendants' intent for healthcare providers and patients to use the Zydus ANDA Product according to its proposed labeling, which will allegedly direct infringement of the asserted claims (Compl. ¶61, ¶89). Contributory infringement is alleged on the basis that the Zydus ANDA Product is not a staple article of commerce and is especially made for an infringing use (Compl. ¶62, ¶90).
  • Willful Infringement: The complaint does not contain a separate count for willful infringement. However, it alleges that Zydus has actual knowledge of the patents-in-suit, at least as evidenced by its Notice Letter and Paragraph IV Certification, and that post-FDA approval, its infringement would be intentional (Compl. ¶57, ¶60, ¶85, ¶88).

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

  • A core issue will be one of factual correspondence: Does the confidential formulation in Zydus's ANDA, once revealed in discovery, contain the exact components in the specific weight percentages and ratios required by claim 1 of the ’214 patent, or did Zydus successfully design around one or more of these limitations?
  • A key evidentiary question will be one of physical characterization: Does the avacopan in Zydus’s final drug product exist in an amorphous form that is “substantially free” of crystalline material and exhibits “no distinct peaks” in an XRPD analysis, as those terms are defined and illustrated within the ’356 patent?
  • A central legal question will be one of claim scope: How will the court construe the definitional boundaries of key terms like "solid solution" and "substantially free," which will directly control whether Zydus's product, once characterized, is found to infringe?