Cydex Pharma Inc v. Alembic Global Holding SA

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: CyDex Pharmaceuticals, Inc. (Delaware)
  • Defendant: Alembic Pharmaceuticals, Ltd. (India); Alembic Global Holding SA (Switzerland); Alembic Pharmaceuticals, Inc. (Delaware)
  • Plaintiff's Counsel: Morris, Nichols, Arsht & Tunnell LLP; Knobbe, Martens, Olson & Bear, LLP
• Case Identification: 1:19-cv-00956, D. Del., 02/07/2020
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Alembic Pharmaceuticals, Inc. is a Delaware corporation and therefore "resides" in the district. The other defendants are foreign corporations that may be sued in any judicial district.
• Core Dispute: Plaintiff alleges that Defendants' filing of an Abbreviated New Drug Application (ANDA) to market a generic version of EVOMELA® constitutes an act of infringement of three U.S. patents related to purified cyclodextrin compositions used in pharmaceutical formulations.
• Technical Context: The patents relate to sulfoalkyl ether cyclodextrins (SAE-CDs), which are used as excipients to improve the solubility and stability of active pharmaceutical ingredients in drug formulations.
• Key Procedural History: This action arises under the Hatch-Waxman Act, triggered by Defendants' filing of ANDA No. 212810. The complaint notes that Plaintiff received a Paragraph IV Certification notice letter from Defendants dated April 8, 2019. The patents-in-suit are listed in the FDA's "Orange Book" as covering the branded drug EVOMELA®.

Case Timeline

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

U.S. Patent No. 9,200,088 - Sulfoalkyl Ether Cyclodextrin Compositions

• Patent Identification: U.S. Patent No. 9,200,088, "Sulfoalkyl Ether Cyclodextrin Compositions," issued December 1, 2015 Compl. ¶18

The Invention Explained

• Problem Addressed: The patent's background section notes that impurities present in sulfoalkyl ether cyclodextrin (SAE-CD) compositions can reduce the shelf-life and potency of an active pharmaceutical ingredient formulated with them '088 Patent, col. 2:10-12
• The Patented Solution: The invention is a purified SAE-CD composition characterized by low levels of specific impurities, namely phosphate and a "UV-active impurity," which is identified by its low light absorption within a specific wavelength range '088 Patent, abstract This high-purity composition can be mixed with an active drug to provide a more stable formulation '088 Patent, col. 2:23-27
• Technical Importance: High-purity excipients are critical in the pharmaceutical industry to ensure drug product stability, prevent degradation of the active ingredient, and maintain efficacy throughout the product's shelf life.

Key Claims at a Glance

• The complaint asserts at least independent Claim 1 Compl. ¶30
• Claim 1 of the '088 Patent includes the following essential elements:
  • A sulfoalkyl ether cyclodextrin (SAE-CD) composition that can be readily mixed with an active agent.
  • The SAE-CD has an average degree of substitution of 4.5 to 7.5.
  • The composition contains less than 200 ppm of a phosphate.
  • The composition has an absorption of less than 0.5 A.U. due to a UV-active impurity, as determined by a specific UV/vis spectrophotometry test method at a wavelength of 245 nm to 270 nm.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 9,493,582 - Alkylated Cyclodextrin Compositions and Processes for Preparing and Using the Same

• Patent Identification: U.S. Patent No. 9,493,582, "Alkylated Cyclodextrin Compositions and Processes for Preparing and Using the Same," issued November 15, 2016 Compl. ¶19

The Invention Explained

• Problem Addressed: Similar to the '088 Patent, this patent addresses the problem of impurities in cyclodextrin compositions reducing the shelf-life and potency of active pharmaceutical ingredients '582 Patent, col. 2:10-14
• The Patented Solution: The invention provides an alkylated cyclodextrin composition with specified low levels of impurities, including phosphate, chloride, and a drug-degrading agent identified by its low absorption in a specific UV wavelength range '582 Patent, abstract The resulting purified composition is intended to provide more stable drug formulations '582 Patent, col. 2:25-29
• Technical Importance: This technology offers another pathway to creating high-purity cyclodextrin excipients, which are essential for developing stable and reliable pharmaceutical products.

Key Claims at a Glance

• The complaint asserts at least independent Claim 27 Compl. ¶39
• Claim 27 of the '582 Patent includes the following essential elements:
  • An alkylated cyclodextrin composition.
  • The alkylated cyclodextrin has an average degree of substitution of 2 to 9.
  • The composition contains less than 500 ppm of a phosphate.
  • The composition contains 0.07% (w/w) or less of a chloride.
  • The composition has an absorption of less than 1 A.U., as determined by a specific UV/vis spectrophotometry test method at a wavelength of 245 nm to 270 nm.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 8,410,077 - Sulfoalkyl Ether Cyclodextrin Compositions

• Patent Identification: U.S. Patent No. 8,410,077, "Sulfoalkyl Ether Cyclodextrin Compositions," issued April 2, 2013 Compl. ¶20
• Technology Synopsis: The patent addresses the technical problem that impurities in SAE-CD compositions can degrade active pharmaceutical agents, thereby reducing a drug's shelf-life and potency '077 Patent, col. 2:10-17 The patented solution is an SAE-CD composition with low levels of both phosphate and a "drug-degrading agent," which is defined by its low absorption under a specific UV/vis spectrophotometry test, enabling the creation of high-stability drug formulations '077 Patent, abstract '077 Patent, col. 2:22-34
• Asserted Claims: At least independent Claim 1 Compl. ¶48
• Accused Features: The complaint alleges that the Alembic ANDA Product contains a sulfoalkyl ether cyclodextrin (SAE-CD) composition that meets the specific purity limitations recited in the claims, including an average degree of substitution of 4.5 to 7.5, less than 100 ppm of phosphate, and low UV absorption due to a drug-degrading agent Compl. ¶48

III. The Accused Instrumentality

Product Identification

• The accused instrumentality is Defendants' proposed generic "Melphalan hydrochloride for injection," which is the subject of Abbreviated New Drug Application (ANDA) No. 212810 (the "Alembic ANDA Product") Compl. ¶1 Compl. ¶7

Functionality and Market Context

• The Alembic ANDA Product is a generic version of Plaintiff's EVOMELA® product Compl. ¶1 The complaint alleges that the Alembic ANDA refers to and relies upon the New Drug Application for EVOMELA® and contains data demonstrating its bioequivalence Compl. ¶26 The complaint alleges that upon FDA approval, Defendants will market and sell the product throughout the United States Compl. ¶26
• No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

9,200,088 Infringement Allegations

9,493,582 Infringement Allegations

• Identified Points of Contention:
  • Factual & Evidentiary Questions: The core of the infringement analysis will likely depend on factual evidence derived from testing Defendants' product and from discovery related to the ANDA filing. The central question will be whether the cyclodextrin composition used in the Alembic ANDA Product actually meets the specific, quantitative limitations recited in the claims regarding average degree of substitution, phosphate levels, chloride levels, and UV absorption.
  • Technical Questions: A potential point of contention may be the execution and interpretation of the analytical test methods prescribed in the patents. The claims define purity based on a specific "UV/vis spectrophotometry" procedure. Disputes could arise over whether Defendants' internal testing methods are equivalent or whether Plaintiff's testing of the accused product accurately reflects its properties according to the patented test.

V. Key Claim Terms for Construction

• The Term: "UV-active impurity" ('088 Patent) / "drug-degrading agent" ('077 Patent)

• Context and Importance: The infringement allegations for the '088 and '077 patents hinge on the low level of this impurity/agent, as measured by a specific UV absorption test. The definition of this term is critical because it defines the very impurity that the patented composition is substantially free of. Practitioners may focus on this term to determine what chemical species, or mixture of species, it encompasses.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patents define the term functionally by its properties. For example, the '077 Patent states a "drug degrading agent" is a "species, moiety, and the like, that degrades an active component in aqueous solution" and has an absorption in the 245 nm to 270 nm range '077 Patent, col. 21:56-62 This could support an interpretation that the term covers any chemical species exhibiting these functional characteristics, regardless of its specific structure.
  • Evidence for a Narrower Interpretation: The specification also provides a list of exemplary species that may constitute a drug-degrading agent, such as "a glycosidic moiety, a ring-opened cyclodextrin species, a reducing sugar, a glucose degradation product..." '077 Patent, col. 22:1-6 A defendant might argue that the term should be construed as being limited to the types of species explicitly disclosed in these examples.

• The Term: "average degree of substitution"

• Context and Importance: This term sets a precise numerical range that is a central limitation in the asserted claims of the '088 and '077 patents. Infringement will depend on whether the accused product's composition falls within this range. Practitioners may focus on this term because the specific methodology for its calculation is defined in the patent and will be dispositive.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The term itself is a standard one in polymer chemistry, suggesting it could be understood by its plain and ordinary meaning to one of skill in the art.
  • Evidence for a Narrower Interpretation: The specifications of the related patents provide a highly specific method for calculating this value, including a mathematical formula based on data from capillary electrophoresis ('077 Patent, col. 14:56-67, Formula I). A party could argue that the term must be interpreted as the result obtained from this exact analytical procedure, potentially excluding values obtained from different methodologies.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that upon approval of the ANDA, Defendants would actively induce infringement Compl. ¶31 Compl. ¶40 Compl. ¶49 The alleged basis for inducement is that Defendants will provide prescribing instructions that will encourage health care professionals, resellers, pharmacies, and end users to directly infringe the patents Compl. ¶32 Compl. ¶41 Compl. ¶50 The complaint also alleges Defendants have knowledge of the patents Compl. ¶32 Compl. ¶41 Compl. ¶50
• Willful Infringement: Willfulness is alleged for all three patents-in-suit Compl. ¶35 Compl. ¶44 Compl. ¶53 The basis for this allegation is that Defendants had actual and constructive knowledge of the patents prior to filing the Alembic ANDA and were aware that filing the ANDA would constitute an act of infringement Compl. ¶33 Compl. ¶42 Compl. ¶51

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

• A central issue will be one of evidentiary proof: can the Plaintiff demonstrate through analytical testing-and discovery from the Defendants' confidential ANDA submission-that the specific cyclodextrin composition in the accused generic product meets all of the quantitative limitations for purity (e.g., phosphate concentration, chloride concentration, UV absorption) and "average degree of substitution" as recited in the asserted claims?
• A key related question will be the application of patented test methods: will the infringement analysis turn on the strict application of the specific UV/vis spectrophotometry and capillary electrophoresis procedures detailed in the patent specifications for measuring the claimed properties, or will disputes over the execution and interpretation of these analytical tests become a central point of contention?