Chemocentryx Inc v. Annora Pharma Pvt Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: ChemoCentryx, Inc. (Delaware)
  • Defendant: Annora Pharma Private Limited (India); Hetero USA Inc. (Delaware); Hetero Labs Limited (India)
  • Plaintiff’s Counsel: Walsh Pizzi O'Reilly Falanga LLP; Gibson, Dunn & Crutcher LLP
• Case Identification: 2:26-cv-01279, D.N.J., 02/09/2026
• Venue Allegations: Venue is alleged to be proper in the District of New Jersey because Defendant Hetero USA Inc. maintains its principal place of business in the district, and Defendants Annora Pharma and Hetero Labs are foreign entities that may be sued in any judicial district. The complaint further alleges the defendants acted in concert to develop and seek approval for the accused product.
• Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to market a generic version of Plaintiff's TAVNEOS® (avacopan) product constitutes an act of infringement of two patents covering specific capsule formulations and the amorphous form of the avacopan active ingredient.
• Technical Context: The technology at issue involves pharmaceutical methods for improving the oral bioavailability of avacopan, a poorly soluble drug used as a C5a receptor antagonist for treating certain autoimmune disorders like ANCA-associated vasculitis.
• Key Procedural History: This is a Hatch-Waxman action initiated under 35 U.S.C. § 271(e)(2) following Defendants' submission of ANDA No. 220814. The lawsuit was triggered by a notice letter and Paragraph IV Certification sent by Defendants, which Plaintiff received on December 29, 2025, alleging that the patents-in-suit are invalid, unenforceable, and/or will not be infringed by the proposed generic product.

Case Timeline

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

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

The Invention Explained

• Problem Addressed: The patent addresses the challenge of creating an effective oral dosage form for avacopan (identified as "Compound 1"), which is characterized as having poor solubility in the aqueous environment of the gastrointestinal tract, making consistent delivery and absorption difficult (’214 Patent, col. 2:46-62).
• The Patented Solution: The invention is a "solid solution capsule" where avacopan is dissolved or dispersed within a specific vehicle. This vehicle is composed of at least one non-ionic surfactant with a high hydrophilic-lipophilic balance (HLB) value and at least one water-soluble solubilizer with a melting point above body temperature ’214 Patent, abstract; ’214 Patent, col. 9:1-9 Upon administration, this formulation is designed to form a microemulsion or nanoemulsion in the stomach, keeping the poorly soluble drug dissolved and available for absorption ’214 Patent, col. 9:1-9
• Technical Importance: This formulation technology provides a stable and consistent oral delivery system for a poorly soluble active pharmaceutical ingredient, which is a common and significant hurdle in drug development.

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶55
• Claim 1 of the ’214 Patent recites the following essential elements:
  • A solid solution capsule formulation comprising [avacopan] as a free base, in its neutral form, or in the form of a pharmaceutically acceptable salt;
  • 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 vehicle further comprising at least one water-soluble solubilizer selected from a group of polyethylene glycols (PEGs) including PEG-4000;
  • Wherein 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; and
  • The total weight of the vehicle comprises a 45:55 to 55:45 ratio of the non-ionic surfactant to the water-soluble solubilizer.

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

The Invention Explained

• Problem Addressed: Similar to the ’214 Patent, the background of the ’356 Patent identifies the poor aqueous solubility of avacopan ("Compound 1") as a challenge for developing bioavailable formulations ’356 Patent, col. 2:46-54
• The Patented Solution: The patent discloses an amorphous, or non-crystalline, solid form of avacopan. Amorphous forms of drugs often exhibit higher solubility and faster dissolution rates compared to their crystalline counterparts ’356 Patent, col. 4:35-42 The specification notes that the claimed amorphous form surprisingly exhibits low hygroscopicity and is physically stable under high humidity, characteristics that are advantageous for pharmaceutical manufacturing and storage ’356 Patent, col. 4:40-46 Figure 2 of the patent shows an X-ray powder diffraction (XRPD) pattern typical of an amorphous material, lacking the sharp peaks associated with crystalline structures ’356 Patent, Fig. 2
• Technical Importance: The invention provides a specific solid-state form of the active ingredient that possesses more favorable physical properties (e.g., solubility) for formulation into a drug product.

Key Claims at a Glance

• The complaint asserts at least independent claims 1 and 21 Compl. ¶84
• Claim 1 of the ’356 Patent recites the following essential elements:
  • 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].

III. The Accused Instrumentality

Product Identification

The accused product is Defendants' generic avacopan capsules, oral, 10 mg, for which regulatory approval is sought under ANDA No. 220814 ("Annora's ANDA Product") Compl. ¶4

Functionality and Market Context

The complaint alleges that Annora's ANDA Product uses the same active ingredient (avacopan), method of administration, dosage form, and dosage amount as ChemoCentryx's TAVNEOS® product Compl. ¶46 The product is intended for the same therapeutic use as TAVNEOS®: as an adjunctive treatment for adult patients with severe active ANCA-associated vasculitis Compl. ¶48 The complaint alleges that upon approval, Defendants intend to market and sell this product in the United States Compl. ¶49

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

11,951,214 Patent Infringement Allegations

11,603,356 Patent Infringement Allegations

• Identified Points of Contention:
  • Compositional and Structural Identity: For both patents, a central question will be evidentiary. The complaint makes its allegations "upon information and belief," which is standard practice in ANDA litigation before discovery. The case will depend on whether the actual formulation and active pharmaceutical ingredient (API) specified in Annora's confidential ANDA submission fall within the scope of the asserted claims. This raises the question of whether Annora's product contains the exact excipients in the claimed ratios (’214 Patent) and whether its API is, in fact, amorphous and "substantially free" of crystalline forms (’356 Patent).
  • Scope Questions: The infringement analysis for the ’214 Patent may require construction of the term "solid solution capsule formulation," raising the question of whether this term requires complete molecular dissolution or can also read on other types of dispersions. For the ’356 Patent, the interpretation of "substantially free" will be critical, as it raises the question of what threshold level of crystalline impurity, if any, is permissible for a product to still be considered infringing.

V. Key Claim Terms for Construction

• The Term: "solid solution capsule formulation" (’214 Patent, claim 1)

• Context and Importance: This term defines the fundamental nature of the claimed invention in the ’214 Patent. Its construction will be dispositive for infringement, as Defendants' product may be argued to be a different type of formulation (e.g., a suspension or simple mixture) even if it uses similar components.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent states the drug substance is "dissolved or dispersed in an excipient matrix," which could suggest that a fine, uniform dispersion short of complete molecular dissolution is covered ’214 Patent, col. 7:1-4
  • Evidence for a Narrower Interpretation: The specification also describes the formulation as appearing "as a uniform solid solution to the naked eye" and lacking "observable clusters of undissolved Compound 1," language which may support an argument that the term requires complete molecular dissolution ’214 Patent, col. 6:1-5

• The Term: "substantially free of other forms" (’356 Patent, claim 1)

• Context and Importance: This term dictates the required purity of the amorphous avacopan. The infringement determination will depend on whether the amount of any crystalline material detected in Annora's product exceeds the threshold permitted by this term. Practitioners may focus on this term because it directly relates to the measurable, physical characteristics of the accused API.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation (Favoring Plaintiff): The specification provides an explicit definition, stating the term 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. 5:16-20 This language provides explicit numerical bounds that could support a finding of infringement even if some crystalline material is present.
  • Evidence for a Narrower Interpretation (Favoring Defendant): A defendant could argue that the term is indefinite due to the series of "preferable" percentages. Alternatively, a defendant might argue that its product contains a level of crystalline material greater than the 10% upper bound or that the amount present is sufficient to place it outside the spirit of the claim.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that Defendants will induce infringement by providing a product label that instructs healthcare providers and patients to use the generic product for the patented therapeutic indication, thereby causing them to directly infringe Compl. ¶¶60-61 Compl. ¶¶88-89 Contributory infringement is also alleged on the basis that the ANDA Product is a material part of the patented inventions, is especially made for an infringing use, and is not a staple article of commerce with substantial noninfringing uses Compl. ¶¶62, 90
• Willful Infringement: The complaint does not contain a formal count for willful infringement. However, it establishes a basis for knowledge and intent for indirect infringement by citing Defendants' Paragraph IV Certification and the associated Notice Letter as evidence that Defendants have actual knowledge of the patents-in-suit Compl. ¶¶57, 85

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

• A core issue will be one of compositional identity: Does the defendant's generic product, as specified in its confidential ANDA, contain the particular non-ionic surfactants and water-soluble solubilizers within the precise weight percentage and ratio limitations required by claim 1 of the ’214 patent?
• A second central question is one of physical form: Will forensic analysis (e.g., via X-ray powder diffraction) of the active pharmaceutical ingredient in the defendant's product demonstrate that it is an "amorphous form... substantially free of other forms" of avacopan, as defined by the claims and specification of the ’356 patent?
• Finally, the case may turn on a key question of definitional scope: How will the court construe the term "solid solution" in the ’214 patent? The outcome of this construction could determine whether a product that is a fine physical dispersion, rather than a complete molecular dissolution, falls within the scope of the claims.