A patent reexamination is a proceeding at the United States Patent and Trademark Office (”PTO”) that looks at an issued patent to determine whether or not the claims should have been issued over prior art that was not considered by the examiner at the time of the original application. Each claim of a patent is presumed valid under 35 U.S.C. 282 and may be enforced notwithstanding the presence of a pending reexamination. Although litigation may move forward in parallel with a reexamination proceeding, at the district court’s discretion, the results of the reexamination proceeding may have an effect on the litigation.
As noted throughout, reexamination can be ex parte or inter partes. In ex parte reexamination, a third party requester will receive copies of office actions and patent owner replies, but cannot otherwise participate in the reexamination proceeding and cannot appeal PTO decisions. In inter partes reexamination, when the patent owner submits a reply to an office action, the third party requester is entitled to file comments in response thereto. The third party’s comments must, however, be limited to issues raised by the office action or in the patent owner’s response. The third party requester is entitled to certain appeals, but is also subject to certain estoppels. Both ex parte and inter partes reexaminations are discussed below.
Other practitioners and commentators have provided summaries of the mechanics of reexamination practice [See, e.g., J. Steven Baughman, Reexamining Reexaminations: A Fresh Look at the Ex Parte and Inter Partes Mechanisms for Reviewing Issued Patents, 89 J. PAT. & TRADEMARK OFF. SOC’Y 349, 360 (2007); Roger Shang & Yar Chaikovsky, Inter Partes Reexamination of Patents: An Empirical Evaluation, 15 Tex. Intell. Prop. L.J. 1 (2006); Sherry M. Knowles, et al., Inter Partes Patent Reexamination in the United States, 86 J. PAT. & TRADEMARK OFF. SOC’Y 611 (2004)].
In order to assure timely delivery of papers, both the third party requester and patent owner should provide the PTO with current correspondence address information. In the past, both the Patent Owner and Third Party Requester utilized the same form when changing correspondence address. The use of the same form resulted in situations where the Patent Owner correspondence address was used by the PTO as the Third Party Requester correspondence address. The PTO has recently introduced a “Patent Owner Change of Correspondence Address” form and a separate “Third Party Requester Change of Correspondence Address” to address these concerns.