Proponents and critics of the Patent Trial and Appeal Board (PTAB) have often debated whether validity challenges brought before it serve more as a sword or a shield—meaning, whether PTAB proceedings are used more as an offensive or defensive measure. While a variety of substantive and strategic considerations may impact a given petitioner’s approach to the PTAB, an important piece of context for this debate is the relationship between district court litigation and PTAB challenges.
To that end, RPX data show that a relatively small percentage of patents that get asserted in district court have been challenged before the PTAB, an overlap shown in the Venn diagram below. Of the roughly 19,500 patents that have been litigated in district court since IPR became available, just over 4,330 of those patents, or 22%, have been hit with petitions for inter partes review (IPR), the most common PTAB proceeding by far. Put another way, the vast majority (~80%) of patents asserted in district court cases do not see a subsequent IPR petition.
Conversely, the data further reveal that district court litigation has been a key driver of PTAB proceedings, as nearly two thirds of the patents challenged in IPR petitions have a preceding district court case involving that patent and the same parties. This overlap is largely the same with no restrictions on party or PTAB petition filing date (i.e., when the data include petitions filed by entities other than a district court defendant as well as petitions filed before a related district court complaint).