Prism Pharma Co Ltd v. JW Pharmaceutical Corp

1. Case Identification

• Case #: IPR2014-00315
• Patent #: 8,318,738
• Filed: December 31, 2013
• Petitioner(s): PRISM Pharma Co., Ltd.
• Patent Owner(s): Choongwae Pharma Corporation
• Challenged Claims: 1-3 and 5-7

2. Patent Overview

• Title: Reverse Turn Mimetics and Methods of Use
• Brief Description: The ’738 patent discloses reverse turn mimetic compounds designed to interact with CREB binding protein (CBP). The goal of this interaction is to inhibit the Wnt cellular signaling pathway, which is implicated in certain types of cancer, by preventing CBP from interacting with β-catenin.

3. Grounds for Unpatentability

Ground 1: Claims 1-3 and 5-7 are anticipated under 35 U.S.C. §102(b) by Odagami.

• Prior Art Relied Upon: Odagami (International Publication No. WO 2009/148192, referred to as the "’192 PCT publication").
• Core Argument for this Ground: Petitioner’s anticipation argument was predicated on establishing that the challenged claims were not entitled to their asserted priority date, thereby making the ’192 PCT publication intervening prior art. The argument proceeded in two main parts: demonstrating a lack of written description support in the priority applications and then mapping the intervening prior art to the challenged claims.
  • Lack of Priority Entitlement: Petitioner argued that the challenged claims were not entitled to a priority date earlier than July 29, 2011, the filing date of the application that issued as the ’738 patent (the ’428 application). The central assertion was that the alleged priority applications, including U.S. Application No. 12/553,858 (the ’858 application), failed to provide adequate written description support for the claimed subject matter as required by 35 U.S.C. §112.
    • The key distinction was a substitution at the "9-position" of the claimed chemical structure (formula VI). Challenged claim 1 recites a compound of formula (VI) substituted with either a hydrogen or a methyl group at the 9-position.
    • Petitioner contended that the general formulas disclosed in the ’858 application’s specification, which were described as the "compounds of the present invention," only allowed for hydrogen atoms at the 9-position. None of the general formulas or synthetic schemes suggested or provided for substitution with a methyl group at this specific position.
    • While the ’858 application included a library of over 3,000 compounds, with seven specific examples containing a methyl at the 9-position, Petitioner argued this was insufficient. These seven examples were not described as part of the invention, did not fall within the disclosed general formulas, and could not provide written description support for the entire claimed genus, which covered thousands of undisclosed structures.
    • Petitioner also argued that the Patent Owner’s attempt during prosecution to cure this defect by incorporating material by reference from another reference (the ’210 PCT publication) was improper. The general, boilerplate incorporation statements in the ’858 application were insufficient to incorporate the specific teachings needed to support the claims, especially since the ’210 PCT publication was cited as background art and distinguished from the invention.
  • Prior Art Mapping: Because the challenged claims lacked written description support in the priority chain, their effective filing date was July 29, 2011. The ’192 PCT publication was published on December 10, 2009, making it prior art under §102(b).
    • Petitioner asserted that the ’192 PCT publication disclosed specific compounds, namely examples I-4 and I-5, that fell squarely within the genus of compounds recited in the challenged claims.
    • For independent claim 1, Petitioner provided a detailed element-by-element mapping showing that compound I-5 from the ’192 PCT publication met every limitation. This included having a bicyclic aryl group at the Ra position, a monocyclic aryl group at the Rb position, a saturated C1 alkyl (methyl) group at the Rc position, and, critically, a methyl group at the 9-position.
    • Dependent claims 2 and 3 were allegedly anticipated by compounds I-5 (unsubstituted bicyclic aryl group) and I-4 (substituted bicyclic aryl group), respectively.
    • Claims 5-7, which recite pharmaceutical compositions, were anticipated because the ’192 PCT publication explicitly disclosed pharmaceutical compositions containing compounds of the invention, including examples I-4 and I-5, along with a pharmaceutically acceptable carrier.

4. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-3 and 5-7 of the ’738 patent as unpatentable.