On November 17, 2017, Genentech filed suit against Pfizer in the District of Delaware, alleging that Pfizer’s biosimilar of Herceptin® infringes forty Genentech patents covering Herceptin® and its methods of use and manufacture. Herceptin® patents have been challenged in IPRs more than any other biologic drug, but this suit marks the first litigation involving Herceptin® filed in district court pursuant to the Biologics Price Competition and Innovation Act (BPCIA).

Herceptin® (trastuzumab) is a recombinant humanized anti-ErbB2 monoclonal antibody. It was approved by the FDA in 1998 to treat patients with ErbB2-overexpressing metastatic breast cancer, a particularly aggressive form of breast cancer. One of the top ten best-selling drugs, worldwide Herceptin® sales continue to grow, surpassing $6.7 billion in 2016.

The Herceptin® portfolio has been actively challenged at the PTAB. A total of thirty IPRs have been filed against Herceptin® patents (twenty-eight in 2017 alone) by six separate petitioners challenging nine different patents. As we reported here, the PTAB has instituted several of these IPRs. Pfizer itself has brought eight challenges (although none have received institution decisions at this time) and several of the patents asserted against Pfizer are the subject of Pfizer’s pending IPR petitions. Genentech has also asserted the so-called Cabilly patents, which, as we reported here, are among the most litigated patents of all time but are not currently the subject of any on-going challenges either at the PTAB or in district court.

In its complaint, Genentech notes that the parties had started participating in the “patent dance” laid out in the BPCIA. Pfizer’s biosimilar application was accepted by the FDA for review on August 21, 2017, and Genentech received a copy of the application on September 5, 2017. Genentech alleged that, despite Pfizer’s refusal to provide “sufficient” manufacturing information, Genentech provided a list of potentially infringed patents pursuant to 42 U.S.C. 262(l)(3)(A) of the BPCIA on November 3, 2017. Although Pfizer had not yet provided its non-infringement and invalidity positions pursuant to subsection (3)(B) of the BPCIA, on November 17, 2017, Pfizer notified Genentech pursuant to subsection (8)(A) that it intends to commence commercial marketing of the Pfizer biosimilar in the United States.  Genentech filed suit the same day.

Genentech’s suit comes in the wake of the Supreme Court’s ruling in Amgen v. Sandoz that allowed biosimilar applicants to provide notice of commercial marketing before FDA approval. Pfizer’s early 180-day notice of commercial marketing allowed Genentech to sue before the patent dance concluded, illustrating the interesting interplay between the provisions of the BPCIA under the Supreme Court’s recent interpretation of the statute.

Although Genentech has not yet filed a motion for a preliminary injunction, Genentech included a preliminary injunction in its requested relief. Should Genentech move on this issue, it will be the first opportunity that a court will have to explore as part of the balance of equities what, if any, weight should be given to a party’s decision to participate in only part of the dance. The Amgen v. Sandoz opinion cast doubt on the mandatory nature of the patent dance, but the Supreme Court included a footnote indicating that a biosimilar manufacturer’s failure to complete the patent dance—as in this case—could still factor into an analysis of preliminary injunctive relief. We will continue to monitor this case for any preliminary injunction filings and other developments.