PTAB

IPR2017-00731

Hospira Inc v. Genentech Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Treatment with Anti-ErbB2 Antibodies
  • Brief Description: The ’441 patent describes methods for treating cancers characterized by the overexpression of the human ErbB2 protein. The claimed method involves administering a combination of an intact anti-ErbB2 antibody that binds to epitope 4D5 and a taxoid chemotherapeutic agent, specifically in the absence of an anthracycline derivative.

3. Grounds for Unpatentability

Ground 1: Obviousness over Baselga ’97 in view of Baselga ’94 - Claims 1-14 are obvious over Baselga ’97 in view of Baselga ’94.

  • Prior Art Relied Upon: Baselga ’97 (Baselga et al., HER2 Overexpression and Paclitaxel Sensitivity in Breast Cancer: Therapeutic Implications, 11(3) ONCOLOGY 43–48 (1997)) and Baselga ’94 (Baselga et al., Anti-HER2 Humanized Monoclonal Antibody (MAb) Alone and in Combination with Chemotherapy Against Human Breast Carcinoma Xenografts, 13 PROC. AM. SOC. CLIN. ONCOL. 63 (1994)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of references taught every limitation of the challenged claims. Baselga ’97 disclosed using a humanized 4D5 antibody (rhuMAb HER2) to treat patients with HER2-overexpressing metastatic breast cancer. It further reported that combining this antibody with the taxoid paclitaxel resulted in "major antitumor activity" in preclinical mouse models, with 93% growth inhibition. Critically, Baselga ’97 stated that based on these encouraging results, a "phase III multinational study of chemotherapy in combination with rhuMoAb HER2" was already underway in human patients. The study design involved administering the antibody with either paclitaxel or an anthracycline, but not both, thus teaching the claimed "absence of an anthracycline derivative." Baselga ’94 provided the foundational preclinical data cited by Baselga ’97, demonstrating a synergistic (93% inhibition) rather than merely additive (35% inhibition alone) effect for the antibody-paclitaxel combination.
    • Motivation to Combine: A POSITA would combine these references because they represent a clear and continuous line of research by the same lead author. Baselga ’97 explicitly cited the preclinical work of Baselga ’94 as the basis for initiating human clinical trials, creating a direct link between the two publications. The shared authorship and direct cross-referencing demonstrated that the later publication was a direct progression of the earlier work.
    • Expectation of Success: A POSITA would have had a strong expectation of success. Baselga ’94 reported a dramatic synergistic effect in preclinical models. More importantly, Baselga ’97 taught that a large-scale Phase III human clinical trial of the exact combination was already in progress, indicating that researchers with ordinary skill had already determined the combination was promising enough to justify extensive human testing.

Ground 2: Obviousness over Baselga ’96 in view of Baselga ’94 - Claims 1-14 are obvious over Baselga ’96 in view of Baselga ’94.

  • Prior Art Relied Upon: Baselga ’96 (Baselga et al., Phase II Study of Weekly Intravenous Recombinant Humanized Anti-p185HER2 Monoclonal Antibody in Patients with HER2/neu-Overexpressing Metastatic Breast Cancer, 14(3) J. CLIN. ONCOL. 737–44 (1996)) and Baselga ’94 (a 1994 journal abstract).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground presented a similar argument to Ground 1, substituting the 1996 publication for the 1997 one. Petitioner asserted that Baselga ’96, which reported results from a Phase II clinical trial of the antibody as a single agent, explicitly disclosed that in preclinical studies, rhuMAb HER2 "markedly potentiated the antitumor effects of several chemotherapeutic agents, including...paclitaxel, without increasing their toxicity." Based on this, Baselga ’96 stated that "clinical trials of such combination therapy [we]re [] in progress." This, combined with the synergistic preclinical data from Baselga ’94, taught the claimed combination, its effectiveness, and its use in humans. The limitation "in the absence of an anthracycline" was taught by the known cardiotoxicity of anthracyclines and Baselga ’94’s data showing the paclitaxel combination was superior to a doxorubicin combination.
    • Motivation to Combine: The motivation was identical to Ground 1. Baselga ’96 also cited Baselga ’94 in its discussion of preclinical testing, shared overlapping authors, and was part of the same public progression of research, motivating a POSITA to read them together.
    • Expectation of Success: The expectation of success was similarly high. Baselga ’96 confirmed that the promising preclinical data from Baselga ’94 had led to ongoing human clinical trials of the combination therapy. The fact that clinical trials were underway demonstrated that a POSITA would have considered the therapy viable and reasonably expected it to succeed.

4. Key Technical Contentions (Beyond Claim Construction)

  • Rebuttal of "No Expectation of Success" Argument: Petitioner directly addressed an argument made by the Patent Owner during the ’441 patent’s prosecution that a POSITA would not have expected success. The prosecution expert (Dr. Sliwkowski) had argued that since rhuMAb HER2 causes G1 cell cycle arrest and paclitaxel causes G2/M arrest, a POSITA would believe the antibody would prevent the chemotherapy from working. Petitioner contended this was incorrect because prior art showed rhuMAb HER2 was compatible with other G2/M-arresting agents (e.g., cisplatin). More fundamentally, Petitioner argued the expert’s hypothesis was directly contradicted by Baselga ’94, which showed a clear synergistic, not antagonistic, effect in vivo.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-14 of the ’441 patent as unpatentable under 35 U.S.C. §103.