As we previously reported, over the past year several petitions requesting Inter Partes Review (IPR) of patents that claim foundational inventions for biologic drug production were filed. Here we discuss the scope of two of the foundational patents that are currently under consideration by the Patent Trial and Appeals Board (PTAB): U.S. Patent No. 6,331,415 (“the ’415 patent” also known as the “Cabilly patent,” after the first inventor’s name) and U.S. Patent No. 6,716,602 (“the ’602 patent”). Both patents are assigned to Genentech, Inc.
As we recently reported, the PTAB has instituted an IPR of the ’415 patent following a petition by Mylan. The ’415 patent was previously unsuccessfully challenged by Genzyme. And although an IPR petition jointly requested by Sanofi Aventis U.S. LLC and Regeneron Pharmaceuticals, Inc., was instituted, this proceeding was later terminated after the petitioners reached a settlement with Genentech.
A petition requesting institution of an IPR of ’602 patent was filed on August 16, 2016, by Bioeq IP AG, and is currently pending.
Production of biologic drugs require expressing the biomolecule in a host cell (bacteria, insect, or cultured human cells), and culturing the cells under conditions that produce large amount of functional and efficacious molecules. With the advent of the recombinant DNA technology in the early 1970s, cloning of a DNA fragment into a plasmid vector, and transformation of the “recombinant plasmid” into E. coli to express the protein encoded in the DNA, were established as foundational methods to express and produce biomolecules.
Claim 1 of the’415 patent is directed to a process for producing antibody or an antibody fragment by two, what are now, conventional steps: transforming a host cell with a first and a second DNA sequences encoding variable domains of the immunoglobulin heavy and light chains, respectively, and independently expressing and producing the heavy and the light chains as separate molecules. These two steps, generally, are widely used in production of many antibodies, which may explain why this patent is the focus of several challenges.
Claim 1 of the ’602 patent covers a method for large scale production of “properly folded” polypeptides, while requiring that the host cells are cultured under conditions of high metabolic and growth rate, and, when the polypeptide expression is induced, modulating the metabolic rate by reducing the feed rate of a carbon/energy source (e.g., glucose) and/or reducing the amount of available oxygen. This method (commonly known as fed-batch method) is currently widely used in many biologic drug production.
We will continue to report on updates to these and BPCIA litigations at the Big Molecule Watch and the IPR tracker page.