On July 23, 2019, Amgen, maker of the cancer treatment drug Neupogen (filgrastim), filed patent infringement claims in the Southern District of California against Tanvex Biopharma over Tanvex’s proposed filgrastim biosimilar in the Southern District of California. See Amgen Inc. v. Tanvex BioPharma USA, Inc., 3:19-cv-01374-BEN-MSB. Amgen asserts a patent that claims methods of refolding recombinant proteins used in the manufacture of Neupogen.
Neupogen is administered to decrease the incidence of infection in patients treated with anti-cancer drugs by stimulating the production of white blood cells. The FDA has already approved two biosimilars of Neupogen—Pfizer’s Nivestym and Sandoz’s Zarxio. Tanvex’s product would be the third (although others have been proposed).
Tanvex submitted its aBLA under the Biologics Price Competition and Innovation ACT (BPCIA) abbreviated licensing pathway in September 2018. According to Amgen’s complaint, Tanvex provided a copy of its FDA submission to Amgen, but did not provide certain manufacturing information required by the BPCIA. After negotiation, Amgen and Tanvex agreed that only one patent, U.S. Patent No. 9,856,287 (“the ‘287 Patent), would be the subject of litigation.
The ’287 Patent is a manufacturing patent relating to refolding proteins, and it is not specific to Neupogen. Amgen asserted the same patent in its suit against Apotex related to biosimilars of both Neupogen and Neulasta (pegfilgrastim), which remains ongoing in the Southern District of Florida. See Amgen Inc. v. Apotex Inc., 0:18-cv-61828-WPD. The patent is also the subject of Amgen’s ongoing case against Adello Biologics relating to Neupogen, Amgen Inc. v. Apotex Inc., 0:18-cv-61828-WPD (D.N.J.). After being sued by Amgen, Adello brought a post grant review proceeding challenging the ’287 Patent, which was instituted by the PTAB in April 2019. See Adello Biologics, LLC v. Amgen Inc., PTAB-PGR2019-00001. Yet another biosimilar maker entered the fray earlier this year, when Fresenius Kabi filed an IPR petition challenging the ’287 Patent in April 2019. See Fresenius Kabi USA, LLC v. Amgen Inc., PTAB-IPR2019-00971.