When implementing a patent reexamination strategy, a threshold determination is whether or not to initiate ex parte or inter partes patent reexamination, or both. This decision is very straight forward for older patents (i.e., those patents that did not mature from an application filed on or after November 29, 1999). This is because applications filed prior to the 1999 date are not eligible for inter partes patent reexamination.

Yet, as the years progress, fewer and fewer patents are outside of the inter partes date provision. So, where both options are available, which is the better option?

Like most legal inquiries, the answer is “it depends.” For those seeking a stay of a parallel litigation, the answer will vary in accordance with the practice of the presiding judge.

As detailed previously, a Nevada judge found that ex parte patent reexamination pendency is controlled by the Patentee, and determined that a stay is appropriate. The judge reasoned that any potential delays in the ex parte proceeding could be controlled by the Patentee.

Last week, in eComSystems Inc., v. Shared Marketing Sevices Inc., and Ace Hardware Corp (MDFL), the judge found that the potential for an ex parte patent reexamination to simplify issues for trial was limited compared to inter partes patent reexamination. The judge explained that estoppel provisions of inter partes patent reexamination would prevent a defendant from arguing the same art in the parallel litigation.