An inter partes review (IPR) is a procedure for challenging the validity of a United States patent before the United States Patent and Trademark Office. The procedure is conducted by the Patent Trial and Appeal Board (PTAB). The inter partes review was enacted on September 16, 2012 as part of the America Invents Act.The new inter partes review procedure replaced a previous review procedure called inter partes reexamination. An inter partes review is used to challenge the patentability of one or more claims in a U.S. patent only on a ground that could be raised under 35 U.S.C. §§ 102 or 103, and only on the basis of prior art consisting of patents or printed publications.
In United States patent law, a reexamination is a process whereby a third party or inventor can have a patent reexamined by a patent examiner to verify that the subject matter it claims is patentable. To have a patent reexamined, an interested party must submit prior art that raises a “substantial new question of patentability”. The Leahy-Smith America Invents Act makes substantial changes to the U.S. patent system, including new mechanisms for challenging patents at the U.S. Patent and Trademark Office. One of the new mechanisms is a post-grant review proceeding, which will provide patent challengers expanded bases on which to attack patents.