PTAB

IPR2018-00625

Kashiv Pharma LLC v. Purdue Pharma LP

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: TAMPER RESISTANT DOSAGE FORMS
  • Brief Description: The ’392 patent discloses tamper-resistant, twice-daily, extended-release pharmaceutical tablets containing an opioid analgesic like oxycodone. The tablets are formed by compressing a matrix containing high molecular weight polyethylene oxide (PEO) and are then "cured" by heating without additional compression to enhance their abuse-deterrent properties.

3. Grounds for Unpatentability

Ground 1: Obviousness over Bartholomaus, McGinity, Oshlack 2, and Oshlack 1 - All challenged claims are obvious over [Bartholomaus](https://ai-lab.exparte.com/case/ptab/IPR2018-00625/doc/1024) in view of [McGinity](https://ai-lab.exparte.com/case/ptab/IPR2018-00625/doc/1025), [Oshlack 2](https://ai-lab.exparte.com/case/ptab/IPR2018-00625/doc/1026), and [Oshlack 1](https://ai-lab.exparte.com/case/ptab/IPR2018-00625/doc/1016).

  • Prior Art Relied Upon: Bartholomaus (Application # 2005/0031546), McGinity (Patent 6,488,963), Oshlack 2 (Application # 2004/0170680), and Oshlack 1 (Patent 5,508,042).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination teaches all elements of the challenged claims. Bartholomaus taught abuse-resistant, extended-release tablets containing oxycodone and high molecular weight (7,000,000 MW) PEO, produced by compression followed by subsequent heating (curing) without pressure to at least the PEO softening temperature. McGinity similarly taught using high MW PEO and heating above 62°C. Oshlack 2 taught curing to achieve stable opioid dissolution. The claimed dosage and PEO percentages were argued to be obvious, as a person of ordinary skill in the art (POSITA) would look to known oxycodone doses (disclosed in Oshlack 1, the original OxyContin patent) and known polymer ratios to achieve a tablet of a suitable size and strength.
    • Motivation to Combine: A POSITA would be motivated to improve the known, abusable formulation of original OxyContin (taught by Oshlack 1) by incorporating the abuse-deterrent features taught by Bartholomaus (high MW PEO for hardness). A POSITA would combine McGinity’s teachings on thermal treatment of PEO and Oshlack 2’s teaching on curing for stability to optimize the manufacturing process and final product characteristics, which are known goals in pharmaceutical development.
    • Expectation of Success: Petitioner asserted a POSITA would have a high expectation of success. The combination involved applying a known process (curing after compression) to a known formulation type (PEO/oxycodone) to achieve a predictable outcome (a stable, abuse-deterrent tablet). Petitioner emphasized that Bartholomaus expressly taught heating after tablet formation, contrary to the Examiner's previous understanding during prosecution.

Ground 2: Obviousness over Wright, Royce, Moroni, and Shao - All challenged claims are obvious over [Wright](https://ai-lab.exparte.com/case/ptab/IPR2018-00625/doc/1017) in view of [Royce](https://ai-lab.exparte.com/case/ptab/IPR2018-00625/doc/1027), [Moroni](https://ai-lab.exparte.com/case/ptab/IPR2018-00625/doc/1028), and [Shao](https://ai-lab.exparte.com/case/ptab/IPR2018-00625/doc/1029).

  • Prior Art Relied Upon: Wright (Application # 2003/0068375), Royce (Patent 5,273,758), Moroni (a 1995 journal article on PEO in sustained-release formulations), and Shao (a 2001 journal article on the effects of curing).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner asserted that Wright taught a sustained-release (12-24 hour), abuse-deterrent matrix containing oxycodone and high MW PEO (up to 10,000,000 MW), which suggests or teaches the core of the claimed invention. Royce and Moroni provided further teachings on using direct compression with high MW PEO (4,000,000 to 6,000,000 MW) to form sustained-release tablets, rendering the claimed PEO concentrations and manufacturing method obvious. Shao taught that curing compressed tablets improves physical properties like hardness, a known advantage for creating abuse-deterrent formulations.
    • Motivation to Combine: A POSITA starting with the abuse-deterrent PEO/oxycodone formulation in Wright would be motivated to use the direct compression methods of Royce and Moroni for manufacturing efficiency. This POSITA would also be motivated to incorporate a final curing step, as taught by Shao, to predictably enhance the tablet's physical stability and hardness, thereby improving its abuse-deterrent properties.
    • Expectation of Success: Success would be expected because the combination merely applies known techniques (direct compression, curing for hardness) to a known base formulation (PEO/oxycodone) to achieve the predictable sum of their individual functions.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 3) based on starting the analysis with Oshlack 1 and combining it with Bartholomaus, McGinity, and Oshlack 2. Petitioner stated this ground relied on the same technical combination and arguments presented in Ground 1 to avoid redundancy.

4. Key Claim Construction Positions

  • "Curing" and Product-by-Process Limitations: Petitioner argued that "curing" should be construed as heating a pre-formed tablet without compression. This construction was central to arguing the Examiner erred in allowing the patent, as the Examiner allegedly believed key prior art (Bartholomaus) required heating with compression.
  • Non-Limiting Process Steps: Petitioner contended that numerous claim recitations—such as specific curing times and temperatures, physical properties (e.g., flattenability, cracking force), and the alleged 1% density decrease (claim 28)—are product-by-process limitations. It was argued these recitations describe the process of making or testing the tablet, not its patentable structure, and therefore should not be given patentable weight in an obviousness analysis.

5. Key Technical Contentions (Beyond Claim Construction)

  • Rebuttal of "Unexpected Results": A central theme of the petition was a direct attack on the Patent Owner's argument of nonobviousness based on an alleged "unexpected" decrease in tablet density upon curing.
    • Petitioner argued the Patent Owner's data supporting the density decrease was methodologically flawed, inconsistent, and insufficient for a POSITA to conclude that a density decrease actually and reliably occurred.
    • Petitioner further argued that even if a density decrease did occur, it was not a "superior result" because the Patent Owner provided no evidence that this change improved any relevant tablet property, such as drug release or abuse deterrence. The petition contended it was a distinction without a difference and therefore could not overcome a strong prima facie case of obviousness.

6. Relief Requested

  • Petitioner requested institution of an inter partes review (IPR) and cancellation of claims 1-3, 5, 7-8, 11-12, 14, 17-20, 24-25, and 27-28 of the ’392 patent as unpatentable.