8 Ways To Avoid Inter Partes Review Estoppel -

Inter partes review has become an enormously popular method of challenging patents. One important downside of filing for IPR, however, is that, if the petitioner loses, it faces an estoppel that could prevent it from raising invalidity defenses in the future. The scope of that estoppel remains unclear. When the America Invents Act established IPR five years ago, most practitioners expected that broad estoppel would apply to preclude a losing petitioner from later asserting almost any prior art invalidity grounds based on patents or printed publications. But recent authority has raised the possibility that a losing petitioner could face much more limited estoppel. We present in this article some strategies that IPR petitioners can implement to try to minimize possible estoppel, preserving their ability to raise invalidity issues in the future.

WHAT IS AN IPR? -

IPR is a proceeding for challenging the validity of patent claims before the Patent Trial and Appeal Board at the U.S. Patent and Trademark Office. Although there is no standing requirement, IPR petitioners are typically defendants accused of patent infringement. An IPR petition includes grounds of anticipation or obviousness based on patents and printed publications. After the patent holder has an opportunity to file a “preliminary response,” the PTAB decides whether to institute the proceeding based on whether the petitioner has shown a reasonable likelihood that it would prevail. If instituted, the IPR then begins, entering the trial phase, during which the parties file briefings and motions and participate in oral argument. The PTAB then issues a final written decision determining the patentability of the instituted claims within one year after institution, about 18 months after the petition was first filed.