PTAB

IPR2022-00201

Fresenius Kabi USA LLC v. Chugai Seiyaku Kabushiki Kaisha Chugai Pharmaceutical Co Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Subcutaneously Administered Anti-IL-6 Receptor Antibody
  • Brief Description: The ’752 patent discloses methods for treating giant cell arteritis (GCA) by administering a fixed 162 mg subcutaneous dose of the anti-IL-6 receptor antibody tocilizumab, either weekly or every other week.

3. Grounds for Unpatentability

Ground 1: Claims 1-16 are obvious over Seitz and Ohta 2010

  • Prior Art Relied Upon: Seitz (a 2011 journal article on treating GCA) and Ohta 2010 (a 2010 abstract on subcutaneous tocilizumab for rheumatoid arthritis).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Seitz taught treating GCA with tocilizumab, but via an intravenous (IV), weight-based administration. Ohta 2010 disclosed that a subcutaneous (SC) fixed dose of 162 mg of tocilizumab administered weekly or every other week was a safe, effective, and preferred regimen for treating rheumatoid arthritis (RA). Petitioner asserted that combining Seitz’s disclosure of treating GCA with tocilizumab with Ohta’s improved SC dosing regimen renders independent claims 1 and 8 obvious. The dependent claims were argued to be obvious as they recite inherent results or conventional additions, such as co-administration with corticosteroids, which Seitz also disclosed.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine these references because both GCA and RA were known IL-6 mediated inflammatory diseases, and it was common practice to apply successful RA regimens to other such disorders. Ohta 2010 provided a known, preferred, and potentially more effective SC administration route that offered improved quality of life and better compliance over the older IV method taught by Seitz. This presented a clear motivation for a POSA to adopt the superior SC regimen for treating the GCA patient population identified in Seitz.
    • Expectation of Success: A POSA would have a reasonable expectation of success. Seitz had already demonstrated that tocilizumab was effective for GCA when administered intravenously. Further, published pharmacokinetic data showed that SC administration of tocilizumab produced comparable therapeutic effects to IV administration. Since Ohta 2010 established the 162 mg fixed SC dose as safe and effective for RA, a POSA would reasonably expect this preferred regimen to also be safe and effective for GCA.

Ground 2: Claims 1-16 are obvious over Hagihara and Ohta 2010

  • Prior Art Relied Upon: Hagihara (a 2010 journal article on treating polymyalgia rheumatica) and Ohta 2010 (a 2010 abstract).
  • Core Argument for this Ground:
    • Prior Art Mapping: Hagihara disclosed the successful treatment of polymyalgia rheumatica (PMR) with IV tocilizumab. Critically, Hagihara noted the established clinical relationship between PMR and GCA and expressly anticipated that tocilizumab could become a treatment option for GCA. Ohta 2010, as in Ground 1, provided the known preferred SC dosing regimen for tocilizumab. Petitioner contended that combining Hagihara’s express suggestion to treat GCA with Ohta’s superior SC administration method renders the claims obvious.
    • Motivation to Combine: The primary motivation stemmed from Hagihara’s explicit suggestion to use tocilizumab for GCA, based on its success in the closely related PMR disorder. A POSA, acting on this suggestion, would be motivated to employ the most advanced, effective, and convenient administration method for tocilizumab known at the time. Ohta 2010 provided exactly that: a 162 mg fixed SC dose administered weekly or bi-weekly, noted for its "ease of use."
    • Expectation of Success: A POSA would reasonably expect success because of the demonstrated efficacy of tocilizumab in PMR, a disorder with a known clinical overlap with GCA. Hagihara’s own anticipation of success in GCA would further bolster this expectation. The known pharmacokinetic equivalence between IV and SC administration, combined with Ohta’s data showing the safety and efficacy of the specific 162 mg SC regimen, provided all the necessary elements for a predictable outcome.

4. Key Claim Construction Positions

  • "fixed dose" (claims 1 and 8): Petitioner argued this term, as defined in the patent’s specification, means a dosage administered without regard to a patient's weight or body surface area (i.e., not a mg/kg or mg/m² dose). This construction was central to Petitioner’s argument, as it distinguished the claimed method from prior art using weight-based dosing and directly mapped onto the 162 mg dose disclosed in Ohta 2010.

5. Arguments Regarding Discretionary Denial

  • §325(d) - Same Art or Arguments: Petitioner argued that discretionary denial under 35 U.S.C. §325(d) would be improper because the core prior art references were not substantively considered by the Examiner during prosecution. Hagihara was never before the Examiner. While Ohta 2010 was cited in an Information Disclosure Statement (IDS), it was never substantively evaluated or discussed. Petitioner contended the Examiner made a material error by allowing the claims based on "unexpected results" compared to prednisone, which was not the closest prior art, while failing to consider Ohta’s disclosure of the exact claimed SC regimen.
  • Fintiv - Parallel Litigation: Petitioner asserted that discretionary denial under the Fintiv factors is inappropriate because there was no co-pending parallel district court litigation. Petitioner argued that the mere potential for future litigation under the Biologics Price Competition and Innovation Act (BPCIA) is speculative and does not satisfy the criteria for a Fintiv denial, which requires an analysis of an existing, parallel proceeding.

6. Relief Requested

  • Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-16 of Patent 9,750,752 as unpatentable.