Amgen Sues Tanvex to Block Proposed Filgrastim Biosimilar

On July 23, 2019, Amgen sued Tanvex BioPharma USA, Inc. and two of its affiliates in the Southern District of California alleging infringement of U.S. Patent No. 9,856,287 under the BPCIA based on Tanvex’s submission of an aBLA for a biosimilar of NEUPOGEN (filgrastim). As relief, Amgen’s complaint requests, among other things, a judgment of infringement and an injunction enjoining Tanvex from engaging in allegedly infringing acts. The complaint indicates that Tanvex provided its subsection (l)(8)(A) notice of commercial marketing on April 1, 2019, indicating “that Tanvex intends to commence commercial marketing … no earlier than 180 days from the date of this letter.”

The ’287 patent is directed to methods of protein refolding in non-mammalian expression systems. According to Amgen’s complaint, prior to the litigation the parties engaged in the patent dance, during which Amgen included the ’287 patent on its subsection (l)(3)(A) patent list and the parties agreed to initially litigate only the ’287 patent.  The case has been assigned to District Court Judge Roger T. Benitez.

Amgen has similarly asserted the ’287 patent against two other filgrastim biosimilar applicants: Apotex, in a case pending in the Southern District of Florida in which the ’287 patent is sole asserted patent; and Kashiv BioSciences (formerly Adello), in a case pending in the District of New Jersey in which the ’287 patent is one of three presently asserted patents. In addition, the ’287 patent is the subject of an instituted post-grant review proceeding (PGR2019-00001) that Adello and Apotex jointly filed this past November and is scheduled for oral argument on January 29, 2020 (if requested). Fresenius Kabi has also challenged certain claims of the ’287 patent in an IPR petition (IPR2019-00971) filed this past April, which is pending PTAB review.

This is the fifth BPCIA litigation concerning a filgrastim biosimilar, following Amgen’s suits against Sandoz, Apotex, Adello, and Pfizer. To date, two filgrastim biosimilars have obtained FDA approval: Sandoz’s ZARXIO (filgrastim-sndz) and Pfizer’s NIVESTYM (filgrastim-aafi), both of which are on the U.S. market.