Ryan Cagle

Most U.S. patent practitioners are keenly aware of the foreign filing license requirement for filing of U.S. patent applications abroad. Since it is common for U.S. based companies to file a U.S. priority patent application and take advantage of the one-year grace period for foreign filing, a foreign filing license is typically issued without much thought to the matter. Given the propensity for international companies and many universities to routinely carry out inventive activities in multiple countries by inventors of varied citizenships, the opportunities to run afoul of foreign filing license requirements is of growing concern, and this concern extends well beyond the walls of the U.S. Patent and Trademark Office (USPTO).

Although the patent prosecution process is adversarial in nature, patent practitioners must be keenly aware of their duty to maintain the integrity of any subsequently issued patent by supplying the patent examiner with all prior art that is believed to be relevant and also avoiding any misrepresentations of the prior art.  Patent litigators have long been aware of the potential pitfall of having a patent invalidated based on inequitable conduct due to activities of a patent prosecutor carried out months or years prior to the litigation proceedings.  In light of a recent decision by the Federal Circuit in Regeneron Pharmaceuticals v. Merus, however, it now appears that inequitable conduct by a patent prosecutor may be inferred due to activities of a patent litigator carried out month or years after patent prosecution has concluded.