Inter Partes Review (IPR) is a formal administrative procedure that allows a third party to challenge the validity of an already-issued patent claim. This process offers a streamlined, faster, and potentially less expensive alternative to challenging a patent in federal court. The mechanism was created to address concerns about patent quality and provide a more efficient forum for reviewing patent grants. IPR is a trial-like proceeding focused exclusively on specific statutory grounds for unpatentability.
Defining Inter Partes Review
Inter Partes Review (IPR) was established as part of the Leahy-Smith America Invents Act (AIA), a significant legislative change enacted in 2011. This process became available in September 2012, replacing the older system of inter partes reexamination, with the goal of modernizing patent validity challenges.
The forum for conducting an IPR is the Patent Trial and Appeal Board (PTAB), which operates within the U.S. Patent and Trademark Office (USPTO). The PTAB functions as an administrative tribunal, overseen by a panel of three administrative patent judges who possess both legal and technical expertise. This setting distinguishes IPR from traditional federal court litigation, as it is an administrative trial with specific rules and procedures.
Grounds for Challenging a Patent
A patent challenge through IPR is strictly limited to arguments based on “prior art,” which includes only patents and printed publications that existed before the patent application was filed. The process does not allow for challenges based on other types of prior art, such as public use or sales of the invention. This limitation focuses the review on documentary evidence.
The challenger must allege that the patent claims are invalid under one of two specific grounds. The first is lack of novelty, meaning the invention was already described in a single prior art document. The second is obviousness, which asserts that the differences between the claimed invention and the prior art would have been readily apparent to a person having ordinary skill in the technical field.
The Review Process
The IPR proceeding begins when a third party files a detailed petition with the PTAB, identifying the specific claims being challenged and the prior art supporting the invalidity arguments. The patent owner then has the option to file a preliminary response arguing against the initiation of the IPR. This initial phase is governed by a strict timeline.
The PTAB must make an “institution decision” within three months of the patent owner’s preliminary response, or six months from the petition filing date if no response is filed. The Board will only institute the IPR if it determines there is a “reasonable likelihood” that the petitioner will prevail on at least one challenged claim. If the challenge is deemed insufficient, the Board will deny institution, ending the process.
If the PTAB institutes the review, a trial phase commences, which involves limited discovery between the parties. This discovery is significantly streamlined compared to federal court, generally limited to the cross-examination of expert witnesses and production of necessary evidence. The PTAB is statutorily required to issue a Final Written Decision within twelve months of the date the review was instituted, ensuring the process remains relatively fast and predictable.
Impact of the Decision
The Final Written Decision issued by the PTAB determines the patentability of the challenged claims. If the challenger successfully proves the claims are invalid, the Board issues a ruling that cancels those specific claims, effectively nullifying that portion of the patent. This outcome has the same effect as a federal court invalidity judgment, removing the enforceable rights of the patent owner for the canceled claims.
A significant consequence of an IPR is the concept of estoppel, which binds the petitioner after a final written decision is issued. Estoppel prevents the petitioner from later raising the same invalidity arguments, or any arguments that reasonably could have been raised, in subsequent proceedings before the USPTO or in federal court litigation. Parties dissatisfied with the PTAB’s Final Written Decision have the ability to appeal the ruling to the U.S. Court of Appeals for the Federal Circuit.