The Federal Circuit has held that the cancellation of patent claims in a Patent Office reexamination acts to extinguish a damages award previously rendered in concurrent district court litigation. This highlights the power of Patent Office proceedings to challenge patent validity, including ex parte reexamination and the recently-enacted Post-Grant Review, Inter Partes Review and Supplemental Examination procedures under the America Invents Act.
Post-Grant Review is available only during the first nine months after issuance of a patent filed after March 16, 2013. After that time, Inter Partes Review becomes available. These proceedings allow a third party to challenge the validity of a patent and remain involved in the proceeding. In contrast, after Supplemental Examination and ex parte reexamination are commenced, only the patent owner can participate. During the short time period in which Inter Partes Review has been available, the Patent Office has accepted approximately 90% of the nearly five hundred petitions seeking review that have been filed.
In many cases, post-grant proceedings provide a more cost-effective and rapid option for adjudicating issues of patent validity than district court litigation. And because the Patent Office adopts the "broadest reasonable interpretation" of patent claims, and requires only a preponderance of the evidence to invalidate patent claims (rather than the clear and convincing evidence required in district court), the Patent Office is an advantageous forum in which to litigate patent validity. Yet, because each of these Patent Office proceedings has its own advantages, tradeoffs and costs, it is important for patent challengers to carefully evaluate the available procedures with knowledgeable counsel to decide which option is most appropriate in any particular case.