Expert Discovery Protections: Comparing District Courts with the PTAB

Expert witness testimony can be critical in patent litigation in all forums. In Patent Trial and Appeal Board (“PTAB”) proceedings, particularly inter partes review (“IPR”) and post-grant review (“PGR”), expert testimony through declarations and depositions plays a central role in both challenging and defending patents. In district courts, live expert testimony is key to proving infringement and invalidity. Accordingly, the legal protections governing the disclosure of expert testimony in discovery in both forums are carefully proscribed, but with notable distinctions.