Celltrion Files Two Additional Petitions for PTO Review of Genentech’s Herceptin Patents

Celltrion has filed two petitions against a Genentech patent with the PTO, requesting an inter partes review of a method for making antibodies related to Herceptin.

The South Korean biosimilars manufacturer recently challenged four Genentech patents for the blockbuster breast cancer drug.

The new petitions say the method is unpatentable, based on scientific papers in 1989 and 1990 that predate the patent — which describe ways to “humanize” antibodies derived from mouse and non-human cell lines, lessening the body’s immune response and allowing their use in several indications.

In March, Genentech settled two Mylan petitions filed with the PTO over the same patent, and granted Mylan a license to develop its own Herceptin (trastuzumab) biosimilar. The FDA accepted the company’s application for review in January.