PTAB

IPR2017-01727

Pfizer Inc v. Genentech Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: ANTI-ERBB2 ANTIBODY ADJUVANT THERAPY
  • Brief Description: The ’897 patent relates to methods of adjuvant therapy for treating nonmetastatic, HER2-positive breast cancer. The claimed method comprises administering an anthracycline/cyclophosphamide (AC) based chemotherapy, followed by the sequential administration of a taxoid (e.g., paclitaxel) and an anti-ERBB2 antibody like trastuzumab.

3. Grounds for Unpatentability

Ground 1: Claims 1-3 and 5-13 are obvious over Clinicaltrials.gov

  • Prior Art Relied Upon: Clinicaltrials.gov (an archived webpage from March 7, 2004, describing the N9831 clinical trial).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the Clinicaltrials.gov reference, which described the N9831 adjuvant trial design, rendered the challenged claims obvious. Specifically, Petitioner asserted that "Arm B" of the N9831 trial taught every element of independent claim 1. This treatment arm involved administering AC chemotherapy to human subjects, followed sequentially by paclitaxel (a taxoid) and then trastuzumab. Petitioner mapped other trial parameters to the claim limitations, arguing the trial enrolled patients with nonmetastatic, HER2-positive breast cancer and that "adjuvant therapy" inherently means the treatment follows definitive surgery. For dependent claims 2-3 and 5-13, Petitioner contended that the reference disclosed or suggested the recited patient subgroups, as the N9831 trial explicitly stratified enrollment based on characteristics such as node-positive status, tumor size, and estrogen/progesterone receptor (ER/PR) status.
    • Expectation of Success: Petitioner contended that a person of ordinary skill in the art (POSITA) would have had a reasonable expectation of success in applying the claimed method. This expectation was based on prior knowledge of trastuzumab's efficacy when used in combination with both taxoids and AC-based chemotherapy in other settings. Furthermore, the fact that the exact regimen was already being administered to patients in a major clinical trial (N9831) since 2000 would have provided a strong basis to expect a successful outcome.

Ground 2: Claim 4 is obvious over Clinicaltrials.gov in view of Tan

  • Prior Art Relied Upon: Clinicaltrials.gov (archived Mar. 7, 2004) and Tan ("Ongoing Adjuvant Trials With Trastuzumab in Breast Cancer," published Oct. 2003).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that claim 4, which recites a specific trastuzumab dosing regimen (an initial 4 mg/kg dose followed by subsequent weekly 2 mg/kg doses), was obvious over the combination of Clinicaltrials.gov and Tan. While Clinicaltrials.gov described the sequential AC→Taxoid→Trastuzumab regimen of N9831's Arm B, it did not specify the exact dosing. Petitioner asserted that Tan, a review article summarizing ongoing adjuvant trials, explicitly disclosed this precise dosing regimen as the one being used for trastuzumab in Arm B of the N9831 trial.
    • Motivation to Combine: Petitioner argued a POSITA reviewing the general trial design on Clinicaltrials.gov would have been motivated to consult other publicly available scientific literature, such as the Tan review article, to obtain more specific details about the N9831 trial's protocol. The Tan reference directly provided the missing dosing information for the regimen described in Clinicaltrials.gov, making the combination straightforward and logical.
    • Expectation of Success: A POSITA would have had a high expectation of success because the claimed dosing regimen was not only the one being actively studied in the large-scale N9831 trial but was also the FDA-approved regimen for trastuzumab at the time of the invention. This combination of factors would have provided a strong rationale to pursue the claimed method with the specified dose.

4. Key Claim Construction Positions

  • Petitioner argued that the preamble of claim 1, “A method of adjuvant therapy,” is not a claim limitation and should not be given patentable weight. It contended the phrase merely states the intended purpose of the method, while the body of the claim recites a structurally complete set of administrative steps.
  • Petitioner proposed that the term “sequential administration” of a taxoid and trastuzumab should be construed to mean that the administration of the two drugs occurs in sequence and does not overlap in time. This construction was presented as critical for distinguishing the invention from prior art involving concurrent therapies. Petitioner asserted this interpretation was supported by the patent’s specification and its prosecution history, where Patent Owner allegedly relied on the sequential nature to overcome rejections.

5. Arguments Regarding Discretionary Denial

  • Petitioner acknowledged that this was the second of two concurrently filed inter partes review (IPR) petitions against the ’897 patent. It argued against discretionary denial by stating that this petition raises distinct statutory grounds based on a different set of prior art (Clinicaltrials.gov and Tan). Petitioner emphasized that this prior art combination was not before the Examiner during the original prosecution and was not asserted in its other concurrently filed petition, thereby presenting new, non-cumulative arguments for unpatentability.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-13 of Patent 8,591,897 as unpatentable under 35 U.S.C. §103.