On June 30, 2017, Pfizer, Inc. (“Pfizer”) filed two new petitions for inter partes review (“IPR”) of U.S. Patent No. 8,591,897 (“the ’897 patent”) related to Genentech’s Herceptin® (trastuzumab).  Pfizer has a trastuzumab biosimilar in phase III development, but it has not yet announced the filing of an application for that product with the FDA.  The company announced positive results in a study in patients with HER2-positive metastatic breast cancer in November 2016.

Trastuzumab is a monoclonal antibody that interferes with the human epidermal growth factor receptor (HER2)/neu. Herceptin® is indicated for the treatment of patients with metastatic breast cancer whose tumors overexpress the HER2 protein and who have received one or more chemotherapy regimens for their metastatic disease.

Pfizer and its subsidiary Hospira have previously filed several IPR petitions challenging certain claims of other patents related to Herceptin® (trastuzumab) as discussed here, here, here and here. The new proceedings are IPR2017-01726 and IPR2017-01727. The only real party-in-interest identified for Petitioner is Pfizer. The ’897 patent, entitled “ANTI-ERBB2 ANTIBODY ADJUVANT THERAPY,” issued on November 26, 2013.

Mylan and Biocon are also seeking approval of a trastuzumab biosimilar. In March 2017, they announced a global settlement and licensing agreement with Genentech and Roche regarding Mylan’s trastuzmab biosimilar, as discussed in this post.

Additionally, Celltrion has filed multiple IPR petitions challenging patents related to Herceptin®, as we reported here, here, and here. A complete list of IPRs related to trastuzumab and other proposed biosimilar products can be found in RFEM’s IPR Dashboard.