What is the requirement for filing an inter partes review?

The requirement for filing an inter partes review (IPR) primarily necessitates that there be "evidence supporting a reasonable likelihood that the petitioner will prevail" with respect to at least one claim challenged in the petition. This means that when a party wishes to contest the validity of a patent through an IPR, they must present sufficient preliminary evidence or arguments demonstrating that it is more likely than not that they will succeed in proving that the claims of the patent are unpatentable.

This evidence requirement is significant because it serves to filter out petitions that lack merit before they proceed to a formal trial phase. If a petitioner cannot establish this preliminary threshold, the IPR will not be instituted, preserving judicial resources and ensuring that only potentially valid challenges are examined further.

Other aspects associated with inter partes review include time constraints related to when a party can file, which typically requires that it be done more than a year after the service of a complaint alleging infringement, among other criteria; however, the crux lies in the demonstration of substantial likelihood of success on the challenge, embodying the intent and procedural structure of the IPR process.