Withholding information that runs directly counter to your central arguments before the PTO constitutes inequitable conduct. Here, for example, withholding earlier letters from a competitor’s in-house counsel that would have corroborated a declaration from the competitor that the patentee attacked as being uncorroborated was found to rise to the level of inequitable conduct.

Background / Facts: The patent being asserted here is directed to prosthetic limb accessories, including in particular cushioning devices consisting of stretchable pieces of synthetic fabric that are coated with a gel on only the side touching the body. During a prior reexamination, the patentee overcame an anticipation challenge based on a competitor’s advertisement and a declaration from the competitor concerning how the advertised product functioned by convincing the PTO that the declaration was uncorroborated. It turns out, however, that the patentee’s corporate officer overseeing the reexamination as well as the present litigation was aware of a pair of corroborating letters received years earlier from counsel for the competitor concerning the similarities between the advertised product and the patents here.

Issue(s): Whether withholding the corroborating letters constituted inequitable conduct.

Holding(s): Yes. “Given the Board’s determination that corroboration was the dispositive issue, and in light of [the patentee’s] assertions before the PTO that there was no corroborating evidence for [the officer’s] testimony, the district court’s determination that the corroborating evidence was material to patentability is not clearly erroneous.” Further, the officer “understood that the appeal to the Board in the [] reexamination turned in substantial part on the question of corroboration,” and “that he could have given his reexamination counsel the [] letters at any point but that he chose not to do so.”

Full Opinion