PTAB

IPR2016-01614

Celltrion Inc v. Genentech Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Treatment of Autoimmune Diseases
  • Brief Description: The ’161 patent discloses methods for treating rheumatoid arthritis (RA) by administering more than one intravenous dose of rituximab, an antibody that binds to the CD20 antigen on B-lymphocytes, in combination with methotrexate.

3. Grounds for Unpatentability

Ground 1: Claims 1-12 are obvious over Edwards 1998, the FDA Conversation, and the Rituxan® Label

  • Prior Art Relied Upon: Edwards et al. (a 1998 journal article), the FDA Conversation (a 1996 publication of a 1995 discussion), and the Rituxan® Label (the 1997 FDA-approved product insert for rituximab).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of these references taught every limitation of the challenged claims. Edwards 1998 explicitly proposed treating RA by depleting B-cells with an anti-CD20 antibody like rituximab. The FDA Conversation documented a consensus among regulators and physicians that new biologic agents for RA should be studied in combination with methotrexate as a standard "background therapy." The Rituxan® Label, approved for treating non-Hodgkin's lymphoma (NHL), disclosed the key treatment parameters: administering more than one intravenous dose (four doses weekly), a specific dose of 375 mg/m² that falls within the range of dependent claims 2, 6, and 10, and the concomitant use of corticosteroids to manage expected infusion-related hypersensitivity reactions (as required by claims 3, 7, and 11). The dose-escalation limitation of claims 4, 8, and 12 was argued to be an obvious application of the general medical principle of titrating drug dosages to minimize side effects.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA), reading Edwards’ proposal to use rituximab for RA, would have been motivated to combine it with methotrexate based on the FDA Conversation’s guidance. This guidance established a clear expectation that new RA biologics would be developed and tested with methotrexate for both ethical and practical reasons, as it was considered the standard of care.
    • Expectation of Success: Petitioner contended a POSA would have had a reasonable expectation of success. The Rituxan® Label established that the proposed dosing regimen was safe and effective at depleting B-cells, the precise mechanism of action proposed by Edwards for treating RA. Since both RA and NHL involved B-cell pathology, applying the known successful treatment protocol from one to the other was a predictable step.

Ground 2: Claims 1-12 are obvious over Edwards 1998, O’Dell, and the Rituxan® Label

  • Prior Art Relied Upon: Edwards et al. (1998), O’Dell (a 1997 journal article), and the Rituxan® Label (1997).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground relied on Edwards and the Rituxan® Label for the same teachings as in Ground 1: the proposal to use rituximab for RA and the specific parameters for its administration (multi-dose, IV, dosage range, and corticosteroid use). The argument for combining this treatment with methotrexate was based on the teachings of O'Dell.
    • Motivation to Combine: Unlike the regulatory motivation in Ground 1, this ground asserted a clinical motivation. Petitioner argued that O’Dell established methotrexate as the "cornerstone" and "foundation" of RA therapy, describing it as the most effective and commonly used disease-modifying antirheumatic drug (DMARD). O'Dell further taught that combination therapy was necessary to achieve remission and that methotrexate was the standard against which other combinations should be measured. Therefore, a POSA seeking to implement Edwards’ suggestion would have been directly motivated by O’Dell to add rituximab to the foundational methotrexate therapy to improve patient outcomes.
    • Expectation of Success: The basis for expecting success was identical to that in Ground 1, stemming from rituximab's known B-cell depleting effects and established safety profile.

  • Additional Grounds: Petitioner asserted a third ground of obviousness over Edwards, Kalden (a 1997 journal article), and the Rituxan® Label. The argument was substantially similar to Ground 2, with Kalden providing a similar clinical motivation as O'Dell by teaching that new biologic agents were being successfully used in combination therapy with methotrexate for RA patients.

4. Key Claim Construction Positions

  • Petitioner argued that no specific claim terms required construction.
  • However, it was a central contention that independent claims 1, 5, and 9 are identical in scope despite minor wording differences. Petitioner asserted that claims 5 and 9 merely make explicit what is inherent in claim 1 (that rituximab is an anti-CD20 antibody administered intravenously in a therapeutically effective amount).
  • Consequently, Petitioner argued that the corresponding sets of dependent claims (e.g., claims 2, 6, and 10) are also identical in scope, allowing all claims to be analyzed in groups based on their added limitations.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-12 of Patent 7,820,161 as unpatentable under 35 U.S.C. §103.