The role of prior art has become important in many PTAB proceedings. Scott D Marty and Jonathon A Talcott discuss evidentiary challenges for petitioners and patent owners.

What good is an invalidity challenge without the prior art? Patent owners and challengers alike are familiar with the central importance of prior art references in post-grant review proceedings brought before the Patent Trial & Appeal Board (PTAB) under the 2011 Leahy-Smith American Invents Act (AIA). But proving the prior in prior art at PTAB has been, until recently, relatively uncontested territory. Recent statistics of AIA proceedings indicate a rising success of patent owner preliminary responses attacking prior art cited by petitioners. So, well-equipped AIA challengers and patent owners should know when and how challenges to prior art succeed in PTAB proceedings.