Under the ex parte system, any person at any time could challenge the validity of a patent on the basis that its claims were obvious or not new based on prior art.
[4] Whereas patent validity used to require a jury trial within the District Courts, the inter partes review process allows the PTAB to hold a hearing with the respective parties and make its decision from that.
[7] Other industries, particularly in the biomedical and pharmaceutical arenas, are critical of the inter partes review as it allows rivals to easily challenge their patents, which generally represent the culmination of large amounts of research and development time and costs.
[10] However, at least one event study indicates that if Bass had in fact pursued such a strategy, he could not have profited, because his "petitions for inter partes review ... did not consistently produce statistically significant negative returns in the patent holders' share prices.
[6] Opponents of the inter partes review have sought both changes in legislation through the United States Congress, as well as seeking case ruling.
[6] In 2018, a federal appeals court ruled that tribal sovereignty did not protect these patents from challenge, as the PTO was simply reconsidering its previous actions.
[15] In 2016, the Supreme Court ruled in Cuozzo Speed Technologies, LLC v. Lee that the patent agency was within the scope of the law to issue regulations that construe claims in an issued patent according to their "broadest reasonable interpretation,"[2] rather than on a more restrictive reading based on their "plain and ordinary meaning," as is the custom in courts.