Ex parte reexamination (EPRx) has been available since 1981 (see MPEP 2200) and remains available under the America Invents Act (AIA). Through ex parte reexamination, the patent owner or a third party may lodge a request for USPTO examination of an already-granted patent based on patents and printed publications that they bring to the USPTO’s attention. Such a request can be filed at any time during the enforceability of a patent, and the requester must establish that the submitted prior art establishes a substantial and new question of patentability (SNQ), at which point the USPTO will grant the reexamination request and order examination (i.e., reexamination) of the patent in question.
For the most part, as its name implies, ex parte reexamination proceedings involve only the patent owner and the USPTO. In fact, after a request is filed, a third-party requester is precluded from further involvement unless the patent owner files a statement seeking to rebut the requester’s assertions of SNQ, in which case the requester may respond to the statement. Thereafter, however, the proceeding excludes the third-party challenger, resembling ordinary prosecution but with several notable exceptions:
1. Ex parte reexamination is conducted before a panel of three experienced examiners within a specialized unit of the USPTO known as the central reexamination unit (CRU);
2. Prosecution of ex parte reexamination effectively closes upon submission of a first response by the patentee, typically precluding submission of evidence and amendments thereafter;
3. Requests for continued examination (RCEs) are not available in ex parte reexamination proceedings; and
4. Extensions of time to respond to communications from the USPTO are not allowed as a matter of right in ex parte reexamination, as they are in regular examination, but instead require a showing of good cause.
The patent owner can appeal the final decision of the CRU to the Patent Trial and Appeal Board (PTAB), and from there, to the U.S. Court of Appeals for the Federal Circuit (CAFC).
No legal estoppel is created by an ex parte reexamination proceeding. But in practice, it may be more difficult to invalidate a challenged patent in another proceeding (such as district court litigation) based on prior art considered by the USPTO during the reexamination proceeding.
The AIA left ex parte reexamination effectively unchanged. The AIA did clarify, however, that the patent owner can appeal only a negative decision of the BPAI (or PTAB) to the Court of Appeals for the Federal Circuit (CAFC).