When the patent owner files a patent owner’s preliminary response (POPR) to an inter partes review petition, the petitioner can request leave to reply before the Board issues its institution decision. Such requests must include “a showing of good cause.”

We wondered if some grounds for “good cause” were more effective than others when a petitioner asks to reply to the POPR. We also asked whether the filing of a reply can predict the outcome of the institution decision. This article examines the most common arguments used in petitioners’ replies to POPRs and how they correspond to outcomes in recent IPR institution decisions. Our analysis also considers the implications for IPR practitioners...