PTAB

IPR2016-01186

Merck Sharp & DOhmen Corp v. Mayne Pharma Intl Pty Ltd

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Pharmaceutical Compositions for Poorly Soluble Drugs
  • Brief Description: The ’745 patent discloses pharmaceutical compositions designed to improve the bioavailability of poorly soluble drugs. The claims are directed to a composition consisting essentially of an azole antifungal drug (e.g., itraconazole) and, in most claims, at least one polymer having acidic functional groups.

3. Grounds for Unpatentability

Ground 1: Anticipation by Kai, Sangekar, Kohri, Babcock, Baert, and Vandecruys - Claims 1-3, 5-7, and 9-14 are anticipated under 35 U.S.C. §102 by each of six separate references.

  • Prior Art Relied Upon: Kai (a 1996 journal article), Sangekar (WO Publication No. WO98/00113), Kohri (a 1999 journal article), Babcock (European Publication No. 1 027 886), Baert (Patent 6,509,038), and Vandecruys (WO Publication No. WO98/42318).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that each of these six references independently discloses every element of the challenged claims. For example, Kai was alleged to disclose a pharmaceutical composition with 100 mg of an azole antifungal drug (MFB-1041) combined with a polymer having acidic functional groups (hydroxypropyl methylcellulose phthalate, "HP-55," which is a preferred polymer in the ’745 patent). Similarly, Sangekar, Kohri, Babcock, Baert, and Vandecruys were each asserted to teach compositions comprising approximately 100 mg of an azole antifungal drug mixed with a qualifying acid-resistant polymer. Petitioner contended that even if the functional "wherein" clauses reciting CMAX and AUC levels were limiting, Kai's reported data far exceeded the claimed thresholds.

Ground 2: Obviousness over Kai, Sangekar, and Babcock - Claims 1-3, 5-7, and 9-14 are obvious over Kai in view of Sangekar and Babcock.

  • Prior Art Relied Upon: Kai (a 1996 journal article), Sangekar (WO Publication No. WO98/00113), and Babcock (European Publication No. 1 027 886).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that these references collectively disclose all elements of the claimed invention. Kai and Sangekar both taught combining a 100 mg dose of a poorly soluble azole with an acid-resistant polymer to improve bioavailability. Babcock taught the same general principle, using the azole fluconazole as an example, and disclosed various suitable polymers. The combination of these references was argued to teach a composition of about 100 mg of an azole antifungal drug and a polymer with acidic functional groups. Dependent claims reciting specific dosage forms like capsules (claims 10, 13) or powders (claims 11, 14) were allegedly obvious, as Babcock taught capsules and Kai taught powders.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these teachings to address the well-known and pressing problem of poor bioavailability in azole antifungals, particularly in light of the AIDS epidemic which created a high demand for effective antifungal treatments. Each reference aimed to solve this exact problem, providing a clear motivation to use their combined teachings.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because each reference demonstrated that combining azoles with acid-resistant polymers was a proven and effective strategy for enhancing solubility and bioavailability. The predictable nature of this formulation strategy, confirmed across multiple publications, would ensure a high likelihood of success.

Ground 3: Obviousness over Kohri, Baert, and Vandecruys - Claims 1-3, 5-7, and 9-14 are obvious over Kohri in view of Baert and Vandecruys.

  • Prior Art Relied Upon: Kohri (a 1999 journal article), Baert (Patent 6,509,038), and Vandecruys (WO Publication No. WO98/42318).

  • Core Argument for this Ground:

    • Prior Art Mapping: This combination was presented as an alternative to Ground 2, with a similar rationale. Kohri, Baert, and Vandecruys each disclosed azole antifungal compositions of about 100 mg combined with polymers having acidic functional groups. For instance, Kohri described a 100 mg dose of albendazole (an azole) with hydroxypropyl methyl cellulose phthalate. Baert and Vandecruys both taught 100 mg dosage forms of itraconazole with various polymers having acidic functional groups.
    • Motivation to Combine: The motivation was identical to the previous ground: to solve the known problem of poor azole bioavailability. These references provided further evidence that this was a common and fruitful area of research, motivating a POSITA to combine their teachings.
    • Expectation of Success: A POSITA would have expected success for the same reasons as the prior ground. The consistent results reported in Kohri, Baert, and Vandecruys for improving azole bioavailability using polymers would reinforce the expectation that such combinations would work predictably.

  • Additional Grounds: Petitioner asserted additional anticipation challenges against claims 1, 3, 5, and 7 based on Thorpe, Tett, and/or Lin, each of which allegedly disclosed a 100 mg dose of an azole antifungal drug without a polymer, which Petitioner argued met the terms of claims where the polymer is "optional."

4. Key Claim Construction Positions

  • "consisting essentially of": Petitioner argued that because the specification focuses on a "solid dispersion" (an unclaimed feature) and fails to identify the basic and novel characteristics of the claimed invention, this transitional phrase should be construed as coextensive with the open-ended term "comprising." This broad construction would allow the claims to read on prior art that included other conventional excipients.
  • "wherein in vivo the composition provides [a certain CMAX or AUC level]...": Petitioner argued these functional clauses, which appear in all independent claims, are non-limiting. The argument was that the clauses merely state an intended result of a structurally complete composition (100 mg of an azole and a polymer) and do not add any structural limitations to the claims themselves. Therefore, prior art disclosing the composition would anticipate or make obvious the claims, regardless of whether the reference reported CMAX or AUC data.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-3, 5-7, and 9-14 of Patent 6,881,745 as unpatentable.