Pfizer Inc v. Genentech Inc

1. Case Identification

• Patent #: 8,591,897
• Filed: June 30, 2017
• Petitioner(s): Pfizer, Inc.
• Patent Owner(s): Genentech, Inc.
• Challenged Claims: 1-13

2. Patent Overview

• Title: ANTI-ERBB2 ANTIBODY ADJUVANT THERAPY
• Brief Description: The ’897 patent is directed to methods of adjuvant therapy for non-metastatic HER2-positive breast cancer. The claimed method comprises administering anthracycline/cyclophosphamide (AC) based chemotherapy, followed by the sequential administration of a taxoid and trastuzumab.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-5 and 8-13 under §102(b) by Piccart-Gebhart

• Prior Art Relied Upon: Piccart-Gebhart et al., "Herceptin: The Future in Adjuvant Breast Cancer Therapy," 12 Anti-Cancer Drugs Suppl. 4, S27-S33 (2001) ("Piccart-Gebhart").
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Piccart-Gebhart, published in 2001, explicitly described the clinical trial protocol for the Intergroup N9831 trial, which disclosed every limitation of the challenged claims. Independent claim 1 recites a method of adjuvant therapy following definitive surgery, comprising AC-based chemotherapy followed by sequential administration of a taxoid and trastuzumab. Petitioner asserted that "Arm B" of the N9831 trial, as depicted and described in Piccart-Gebhart, identically matched this sequence: AC chemotherapy, followed by paclitaxel (a taxoid), followed by Herceptin (trastuzumab).
  • Prior Art Mapping (Dependent Claims): Petitioner contended that Piccart-Gebhart also anticipated dependent claims 2-5 and 8-13. The reference allegedly disclosed paclitaxel as the taxoid (claim 2), trastuzumab as the antibody (claim 3), and the specific 4 mg/kg loading dose followed by 2 mg/kg weekly doses (claim 4). Furthermore, the trial's patient eligibility and stratification protocol explicitly included patients with high-risk characteristics, such as being node-positive (claim 8), having 4-9 or ≥10 involved lymph nodes (claims 9-10), and being ER/PR-negative (claims 11-12), thereby anticipating these claims as well.

Ground 2: Anticipation of Claims 1-7 under §102(a) by Perez

• Prior Art Relied Upon: Perez et al., "Effect of Doxorubicin Plus Cyclophosphamide on Left Ventricular Ejection Fraction in Patients with Breast Cancer in the North Central Cancer Treatment Group N9831 Intergroup Adjuvant Trial," 22 J. Clinical Oncology 3700 (Sept. 15, 2004) ("Perez").
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Perez, while focused on cardiovascular data, also described the treatment protocol for the N9831 trial and anticipated claims 1-7. Like Piccart-Gebhart, Perez allegedly disclosed the "AC -> taxoid -> trastuzumab" sequence for treating non-metastatic, HER2-positive breast cancer patients post-surgery, thus meeting all limitations of independent claim 1.
  • Prior Art Mapping (Dependent Claims): Petitioner asserted that Perez explicitly disclosed details anticipating claims 2-7. Perez identified the taxoid as paclitaxel (claim 2) and the antibody as trastuzumab (claim 3) administered at the claimed dosage (claim 4). Crucially, Perez provided baseline patient characteristics for the N9831 trial, disclosing that patients were high-risk (claim 5), that over half of the enrolled patients were under 50 years old (claim 6), and that an eligibility criterion for some patients was having tumors larger than 2 cm (claim 7).

Ground 3: Obviousness of Claims 1-13 under §103 over Piccart-Gebhart in view of Thomas

• Prior Art Relied Upon: Piccart-Gebhart (2001) and Thomas et al., "New paradigms in adjuvant systemic therapy of breast cancer," 10 Endocrine-Related Cancer 75-89 (2003) ("Thomas").
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Piccart-Gebhart disclosed the core treatment regimen (AC -> taxoid -> trastuzumab), and Thomas provided the rationale that would have made applying this regimen to the specific patient populations of claims 6 and 7 obvious. Thomas, a review article on adjuvant therapy standards, allegedly taught that women younger than 50 and patients with tumors larger than 2 cm were known high-risk groups who derive the most benefit from adjuvant therapy. Petitioner argued that even if Piccart-Gebhart did not explicitly disclose these patient characteristics, Thomas rendered it obvious to apply the Piccart-Gebhart regimen to them.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to combine the teachings. Trastuzumab was known to be highly effective in the metastatic setting, and its use in the adjuvant setting was the logical next step in drug development. Thomas established that AC followed by a taxoid (AC→T) was a standard-of-care adjuvant regimen. A POSITA would have been motivated to add trastuzumab to this known, effective regimen to improve outcomes. The sequential administration (AC→T→H) was a particularly motivated choice to mitigate the known increased cardiotoxicity associated with concurrent administration of anthracyclines (in AC) and trastuzumab.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success. The efficacy of trastuzumab was well-established, and the AC→T regimen was a standard of care. Combining them in a sequence designed to minimize known side effects (cardiotoxicity) would have been a predictable and promising therapeutic strategy for high-risk, non-metastatic breast cancer.

4. Key Claim Construction Positions

• "Sequential administration": Petitioner argued for a construction of "sequential administration of a taxoid and trastuzumab" to mean that the administrations occur one after the other and do not overlap in time. This construction was allegedly supported by the specification's explicit definition of "concurrently" as overlapping in time, creating a clear distinction. Petitioner also noted that the Patent Owner relied on this sequential nature during prosecution to distinguish the invention from prior art that taught concurrent administration.
• Preamble ("a method of adjuvant therapy"): Petitioner asserted that the preamble is not a limitation because it merely states the intended purpose of the method, and the body of the claim describes a structurally complete invention.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-13 of the ’897 patent as unpatentable.