DCT

2:17-cv-06090

Aptalis Pharma US Inc v. Amneal Pharma LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:17-cv-06090, D.N.J., 08/11/2017
  • Venue Allegations: Venue is alleged to be proper in the District of New Jersey because Defendants conduct systematic business in the state, Amneal Pharmaceuticals LLC has its principal place of business in New Jersey, and notice of the ANDA was sent from its New Jersey headquarters.
  • Core Dispute: Plaintiff alleges that Defendant’s filing of an Abbreviated New Drug Application (ANDA) for a generic version of Plaintiff's CANASA® product constitutes an act of infringement of three patents related to mesalamine suppository formulations.
  • Technical Context: The technology concerns pharmaceutical formulations for mesalamine rectal suppositories, used to treat inflammatory bowel diseases like ulcerative proctitis, with a focus on improving patient comfort by reducing suppository size while maintaining therapeutic efficacy.
  • Key Procedural History: This lawsuit was triggered by Defendant Amneal's submission of ANDA No. 210509 to the FDA, seeking approval to market a generic 1000 mg mesalamine suppository. As part of the ANDA process, Amneal filed a "paragraph IV certification" asserting that Plaintiff's patents are invalid, unenforceable, and/or not infringed by Amneal's proposed product, which serves as the statutory basis for this infringement action.

Case Timeline

Date Event
2007-06-08 Priority Date for ’384, ’083, and ’051 Patents
2009-06-02 Issue Date for U.S. Patent No. 7,541,384
2012-07-10 Issue Date for U.S. Patent No. 8,217,083
2013-05-07 Issue Date for U.S. Patent No. 8,436,051
2017-04-28 Date on or before which Amneal submitted its ANDA
2017-06-28 Date on or about which Amneal sent its Paragraph IV notice
2017-08-11 Complaint Filing Date

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

U.S. Patent No. 7,541,384 - Mesalamine Suppository

  • Patent Identification: U.S. Patent No. 7,541,384, "Mesalamine Suppository," issued June 2, 2009.

The Invention Explained

  • Problem Addressed: The patent's background section notes that existing mesalamine suppositories are of a "substantial size" and identifies a "need for mesalamine suppositories which provide increased comfort of use" (’384 Patent, col. 2:8-12).
  • The Patented Solution: The invention is a smaller mesalamine suppository that maintains therapeutic efficacy. The inventors discovered this could be achieved by increasing the "tap density" of the mesalamine active ingredient, which decreases the viscosity of the drug-base mixture during manufacturing ('384 Patent, col. 2:28-32; FIG. 1-3). This allows for a higher concentration (drug load) of mesalamine to be formulated into a smaller overall suppository without compromising its physical properties or dissolution profile ('384 Patent, col. 2:16-24).
  • Technical Importance: The formulation method allowed for a significant reduction in the physical size of the suppository, which may improve patient compliance and comfort for a chronic condition.

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims" (’384 Patent, Compl. ¶19). Independent claim 1 is representative.
  • Claim 1 requires:
    • A mesalamine rectal suppository comprising from about 850 to about 1150 mg of mesalamine and a fatty base;
    • The mesalamine has a tap density ranging from about 600 to about 800 g/L;
    • The drug load of the suppository ranges from 35% to 46%; and
    • The suppository releases at least 75% by weight of the mesalamine within 2 hours under specific dissolution test conditions.

U.S. Patent No. 8,217,083 - Mesalamine Suppository

  • Patent Identification: U.S. Patent No. 8,217,083, "Mesalamine Suppository," issued July 10, 2012.

The Invention Explained

  • Problem Addressed: The patent addresses the same problem as its parent '384 Patent: the need for a smaller, more comfortable mesalamine suppository than what was previously available ('083 Patent, col. 2:8-12).
  • The Patented Solution: This patent continues the same technical approach of using mesalamine with a high tap density to enable a smaller suppository size ('083 Patent, col. 2:20-32). The claims are structurally similar to those in the '384 patent but include different dosage ranges, such as a claim directed to a suppository with 450 to 550 mg of mesalamine ('083 Patent, col. 14:21-23).
  • Technical Importance: This patent expands the protection on the core invention to cover different dosage strengths, broadening the proprietary formulation platform.

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims" (’083 Patent, Compl. ¶38). Independent claim 1 is representative.
  • Claim 1 requires:
    • A mesalamine rectal suppository comprising mesalamine and an oily or fatty base;
    • The mesalamine has a tap density ranging from about 600 to about 800 g/L;
    • The suppository has a drug load ranging from 35% to 50%; and
    • The suppository releases at least about 75% by weight of the mesalamine within 2 hours under specific dissolution test conditions.

U.S. Patent No. 8,436,051 - Mesalamine Suppository

  • Patent Identification: U.S. Patent No. 8,436,051 ("the '051 Patent"), "Mesalamine Suppository," issued May 7, 2013.
  • Technology Synopsis: The '051 Patent continues the inventive concept of optimizing mesalamine suppositories. It introduces the surface area of the mesalamine particles as another key parameter to control the drug's dissolution rate. The patent discloses the discovery that, contrary to common scientific belief for poorly soluble drugs, a decrease in the surface area of the mesalamine particles can lead to an increase in the dissolution rate from the suppository ('051 Patent, col. 2:33-39).
  • Asserted Claims: The complaint asserts infringement of "one or more claims" of the '051 Patent (Compl. ¶57).
  • Accused Features: Amneal's proposed generic mesalamine suppository is alleged to possess the formulation characteristics, including drug load and release profiles related to particle surface area, as claimed in the '051 Patent (Compl. ¶¶58-59).

III. The Accused Instrumentality

Product Identification

  • "Amneal's Proposed Product" is identified as generic mesalamine 1000 mg rectal suppositories, for which Amneal seeks FDA approval via ANDA No. 210509 (Compl. ¶9).

Functionality and Market Context

  • The product is a generic version of Aptalis's branded drug, CANASA®, which is approved for the treatment of active ulcerative proctitis (Compl. ¶10). The act of infringement alleged in an ANDA case is statutory; by filing the ANDA, Amneal is seeking to make, use, or sell a drug claimed in a patent before its expiration, which constitutes infringement under 35 U.S.C. § 271(e)(2) (Compl. ¶19). The complaint alleges that upon approval, Amneal intends to commercially manufacture and sell the product in the United States (Compl. ¶9). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not provide detailed infringement contentions or claim charts, as is common at the pleading stage of an ANDA case. The allegations are based on information and belief that the product described in Amneal's confidential ANDA submission will meet the limitations of the asserted claims.

’384 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A mesalamine rectal suppository comprising from about 850 to about 1150 mg of mesalamine and a fatty base... Amneal's Proposed Product is a 1000 mg mesalamine rectal suppository, which is alleged on information and belief to be formulated with a fatty base. ¶9, ¶20 col. 14:12-14
...wherein the mesalamine has a tap density ranging from about 600 to about 800 g/L (as measured by USP <616>)... It is alleged on information and belief that the mesalamine in Amneal's Proposed Product will have a tap density within the claimed range. ¶20 col. 14:14-16
...the drug load of the suppository ranges from 35% to 46%... It is alleged on information and belief that Amneal's Proposed Product will have a drug load within the claimed range. ¶20 col. 14:17-18
...and the suppository releases at least 75% by weight of the mesalamine within 2 hours of dissolution as measured with USP Apparatus #2 at 40° C., a paddle rotation speed of 125 rpm, and 3 sinker turns in 0.2 M phosphate buffer at a pH of 7.5. It is alleged on information and belief that Amneal's Proposed Product will meet the specified dissolution profile to be bioequivalent to the branded CANASA® product. ¶20 col. 14:18-24

’083 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A mesalamine rectal suppository comprising mesalamine and an oily or fatty base... Amneal's Proposed Product is a mesalamine rectal suppository, which is alleged on information and belief to be formulated with an oily or fatty base. ¶9, ¶39 col. 14:12-13
...wherein the mesalamine has a tap density ranging from about 600 to about 800 g/L (as measured by USP <616>)... It is alleged on information and belief that the mesalamine in Amneal's Proposed Product will have a tap density within the claimed range. ¶39 col. 14:14-16
...the suppository has a drug load ranging from 35% to 50%... It is alleged on information and belief that Amneal's Proposed Product will have a drug load within the claimed range. ¶39 col. 14:16-18
...and the suppository releases at least about 75% by weight of the mesalamine within 2 hours of dissolution as measured with USP Apparatus #2 at 40° C., a paddle rotation speed of 125 rpm, and 3 sinker turns in 0.2 M phosphate buffer at a pH of 7.5. It is alleged on information and belief that Amneal's Proposed Product will meet the specified dissolution profile to be bioequivalent to the branded CANASA® product. ¶39 col. 14:18-24
  • Identified Points of Contention:
    • Factual Question: The central dispute will be factual: does the formulation detailed in Amneal's confidential ANDA meet the specific quantitative limitations recited in the claims regarding tap density, drug load, and dissolution rate? Amneal's Paragraph IV certification asserts non-infringement, creating a direct conflict with Aptalis's allegations (Compl. ¶16, ¶37).
    • Scope Question: A key legal question will concern the interpretation of the word "about" preceding each numerical range in the claims. The extent to which "about" expands these ranges could be determinative if Amneal's product specifications lie near the recited boundaries.

V. Key Claim Terms for Construction

  • The Term: "about"

    • Context and Importance: This term modifies every quantitative limitation in the independent claims (e.g., "about 850 to about 1150 mg," "about 600 to about 800 g/L"). Its construction is critical because it defines the boundaries of the claimed invention. The infringement analysis for a product with characteristics near the specified numerical values will depend entirely on the scope afforded to this term.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The repeated and consistent use of "about" before numerical values throughout the specification and claims may suggest the patentee did not intend to be limited to the exact numbers recited ('384 Patent, col. 14:12-24).
      • Evidence for a Narrower Interpretation: The specification provides extensive experimental data with specific values for viscosity, tap density, and dissolution ('384 Patent, Tables 9-12). A party could argue that the precision of these examples informs and limits the meaning of "about" to a narrow range of equivalents consistent with the data.

  • The Term: "tap density"

    • Context and Importance: Tap density is the core technical characteristic upon which the invention is based; the inventors discovered that controlling this parameter allowed them to solve the problem of high viscosity in manufacturing and thereby create a smaller suppository. Practitioners may focus on this term because infringement hinges on whether Amneal's product uses mesalamine with the claimed tap density.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The claim language itself does not impose limitations beyond the specified numerical range and measurement method.
      • Evidence for a Narrower Interpretation: The claims explicitly require that tap density be "measured by USP <616>" ('384 Patent, col. 14:15-16). This incorporation of an external, standardized test method provides a specific, replicable definition. The specification further links tap density directly to the viscosity of the molten mixture, which it sought to control, providing significant context for why this specific range is important ('384 Patent, FIG. 1-3). Any dispute may center on the precise application of the USP <616> methodology.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, stating that Amneal knows and intends for physicians and patients to use its proposed product in accordance with the proposed label for the patented indication, thereby inducing infringement of the method claims (Compl. ¶¶21-22, 40-41, 59-60).
  • Willful Infringement: Willfulness is alleged based on Amneal's awareness of the patents-in-suit prior to filing its ANDA, as evidenced by its Paragraph IV certification (Compl. ¶¶23, 37, 42, 61). The complaint also seeks a finding that the case is "exceptional" under 35 U.S.C. § 285, which would entitle Aptalis to attorneys' fees (Compl. ¶24).

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

The resolution of this case will likely depend on the answers to three central questions:

  1. A core issue will be one of evidentiary proof: Does the specific formulation detailed in Amneal's confidential ANDA—particularly the tap density of the mesalamine, the final drug load, and the dissolution profile—fall within the numerical ranges of the asserted claims?
  2. A secondary issue will be one of definitional scope: How will the court construe the term "about"? This will determine whether Amneal's product infringes if its formulation characteristics are proximate to, but not exactly matching, the recited numerical limits.
  3. A critical question for the defense will be patent validity: Given that mesalamine and suppository bases were known, would it have been obvious to a skilled formulator to increase the tap density of the active ingredient to achieve the claimed formulation with its specific properties? Amneal's Paragraph IV letter indicates it will challenge the patents on this basis.