PTAB

IPR2022-01065

Fresenius Kabi USA LLC v. Chugai Seiyaku Kabushiki Kaisha

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Subcutaneously Administered Anti-IL-6 Receptor Antibody for Treatment of Juvenile Idiopathic Arthritis
  • Brief Description: The ’981 patent is directed to methods of treating juvenile idiopathic arthritis (JIA) by subcutaneously administering a fixed dose of 162 mg of tocilizumab (an anti-IL-6 receptor antibody) at specified frequencies.

3. Grounds for Unpatentability

Ground 1: Anticipation over the ’264 Patent - Claims 1-14 are anticipated by Patent 8,580,264.

  • Prior Art Relied Upon: Patent 8,580,264 (’264 patent).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the ’981 patent is not entitled to its claimed priority dates because the priority applications lack written description support for a key claimed element: a three-week administration frequency. This results in an effective priority date of August 3, 2017. The ’264 patent, issued in 2013, therefore qualifies as intervening prior art under 35 U.S.C. §102. Petitioner asserted that the ’264 patent, which shares an almost identical specification with the ’981 patent, explicitly discloses treating JIA with a 162 mg fixed subcutaneous dose of tocilizumab, including specific regimens for systemic JIA (sJIA) and polyarticular course JIA (pcJIA) that fall within the scope of the challenged claims. For example, the ’264 patent allegedly discloses treating sJIA patients with 162 mg every week and pcJIA patients with 162 mg every two weeks.
    • Key Aspects: The validity of this ground rests on successfully challenging the ’981 patent’s priority claim, which allows the otherwise-related ’264 patent to be used as anticipatory prior art.

Ground 2: Anticipation over Clinical Trial Protocol - Claims 1-14 are anticipated by NCT02165345.

  • Prior Art Relied Upon: NCT02165345 (a clinical trial protocol published on ClinicalTrials.gov).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that the NCT02165345 protocol was publicly available as a printed publication as early as June 2014, making it prior art to the ’981 patent’s 2017 effective priority date. The protocol, an extension study for evaluating subcutaneous tocilizumab, allegedly discloses every limitation of the challenged claims. It explicitly describes a method of treating JIA by administering a 162 mg fixed subcutaneous dose of tocilizumab. Specifically, it laid out the exact weight- and subtype-based dosing regimens recited in the dependent claims: treating pcJIA patients weighing <30 kg every three weeks and ≥30 kg every two weeks; and treating sJIA patients weighing <30 kg every two weeks and ≥30 kg every week. Petitioner argued the efficacy of the treatment was inherent and also disclosed, as a criterion for entering this extension study was having adequate disease control from prior studies using the same drug.

Ground 3: Obviousness over Herlin and Ohta - Claims 1-14 are obvious over Herlin in view of Ohta 2010.

  • Prior Art Relied Upon: Herlin (a 2009 journal article titled "Tocilizumab: The evidence for its place in the treatment of juvenile idiopathic arthritis") and Ohta 2010 (a published clinical trial abstract).

  • Core Argument for this Ground:

    • Prior Art Mapping: Herlin disclosed the successful and safe treatment of both sJIA and pcJIA using intravenous (IV), weight-based doses of tocilizumab. Ohta 2010 disclosed the successful treatment of rheumatoid arthritis (RA), a related IL-6 mediated disease, using a subcutaneous fixed dose of 162 mg of tocilizumab administered weekly or every other week. Petitioner argued that combining these references renders the claimed methods obvious.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would have been motivated to apply the more convenient and preferred subcutaneous administration method taught by Ohta to the treatment of JIA taught by Herlin. At the time of the invention, subcutaneous administration was a known and desirable alternative to IV infusions for antibody therapies, offering benefits like home administration and improved patient quality of life. The POSA would have looked to Ohta’s successful use of a 162 mg fixed dose for RA and been motivated to apply it to JIA, another IL-6 mediated inflammatory disease.
    • Expectation of Success: A POSA would have had a reasonable expectation of success. The art demonstrated that subcutaneous administration of antibodies was at least as safe and effective as IV administration. Ohta showed that a 162 mg subcutaneous dose was effective for RA. A POSA would have reasonably expected this success to translate from RA to JIA, especially since Herlin confirmed tocilizumab’s efficacy in JIA. The specific frequencies claimed were allegedly obvious calculations to achieve a total dosage over time equivalent to the effective IV regimens described in Herlin.

  • Additional Grounds: Petitioner asserted that claims 1-14 are also obvious over NCT02165345 alone, arguing that even if the protocol does not anticipate, a POSA would have been motivated to implement its disclosed regimens with a reasonable expectation of success.

4. Key Claim Construction Positions

  • "fixed dose" (claims 1 and 8): Petitioner asserted that this term should be construed according to its definition in the ’981 patent’s specification: "a dosage of a drug, such as an anti-IL-6R antibody which is administered without regard to the patient’s weight or body surface area (BSA), i.e., it is not administered as either a mg/kg or mg/m² dose."

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) based on Fintiv factors is inappropriate because there was no parallel district court proceeding.
  • Petitioner further argued that denial under §325(d) would be improper. The core argument is that the Examiner failed to consider whether the ’981 patent was entitled to its claimed priority date—a central issue to the petition's primary grounds. Because this argument was not previously presented to or considered by the Patent Office, denial is not warranted. Furthermore, Petitioner relied on references (NCT02165345 and Herlin) that were not before the Examiner during prosecution.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-14 of the ’981 patent as unpatentable.