What Is Inter Partes Review?

A description of the patent challenge proceeding and how it differs from district court litigation.

The inter partes review (IPR) proceeding was established under the America Invents Act of 2011 to provide a cheaper, faster alternative to district court litigation to resolve disputes over patent validity. It went into effect on Sept. 16, 2012.

Any party other than the patent owner can file a petition with the US Patent and Trademark Office's Patent Trial and Appeal Board (PTAB) challenging the validity of a patent's claims beginning nine months after the patent issues. The petitioner can only challenge the patent on grounds that it is not novel or is obvious and only on the basis of prior art consisting of patents or printed publications.

If a party has been sued for infringing the patent at issue, it must file the IPR petition within one year of being served with the complaint.

A three-judge panel of PTAB has six months to decide whether to institute review. It does so only if it finds there is a "reasonable likelihood" that the petitioner would prevail with respect to at least one of the claims challenged in the petition. Parties cannot appeal the decision on institution.

If the Board institutes review it conducts a trial-like proceeding to determine the patentability of the patent claims. The patent owner can file one motion to amend the patent. The Board must issue a final written decision within one year after instituting review. Parties may appeal the decision to the US Court of Appeals for the Federal Circuit.

If the board grants inter partes review and issues a final decision, the petitioner is estopped from requesting or maintaining a proceeding before PTAB with respect to any claim or ground it raised or reasonably could have raised during the IPR. The petitioner is also barred from asserting in district court that a claim is invalid on any grounds it raised or reasonably could have raised during the IPR.

PTAB and district courts have different legal standards. There is no presumption of a patent's validity in an IPR proceeding as there is in district court litigation. PTAB uses the "broadest reasonable interpretation" standard for determining the meaning of patent claim terms rather than the ordinary and customary meaning used by district courts. And PTAB requires petitioners to establish the unpatentability of a patent claim by a "preponderance of the evidence" rather than by "clear and convincing evidence" as required by district courts.

As of Sept. 30, a total of 6,955 IPR petitions had been filed. Of these, 1,901 were filed in fiscal year 2017, 221 (11%) of which were in the bio/pharma sector.

The institution rates (petitions instituted divided by decisions on institution) have declined from 87% in FY 2013 to 63% in FY 2017 for all sectors.

As of Sept. 30, PTAB had issued 1,771 final written decisions. All instituted claims were found unpatentable in 1,153 decisions (65%), some claims were found unpatentable in 287 decisions (16%) and no claims were found unpatentable in 331 cases (19%).