What is the requirement for filing an inter partes review?

The requirement for filing an inter partes review (IPR) focuses on the necessity to demonstrate sufficient preliminary evidence. This includes providing evidence that establishes a reasonable likelihood of prevailing on at least one of the challenged claims. The IPR process is intended to provide a mechanism for third parties to challenge the validity of issued patents based on prior art.

To initiate an IPR, petitioners must substantiate their claims with credible evidence indicating that they have a strong case against the patent’s validity. This requirement ensures that only petitions with a genuine basis for challenging the patent will proceed, as the IPR mechanism is designed to assess potential invalidity effectively and efficiently.

The other options do not align with the critical requirement for filing an IPR. For example, the one-year limitation after the service of a complaint pertains to specific timing restrictions but is not the primary basis for the initiation of the IPR itself. References to modifications of claims and whether claims have been previously challenged do not provide the foundational evidentiary criteria necessary for establishing a case in an IPR context. Thus, the requirement to show a reasonable likelihood of success is central to the initiation of an inter partes review.