In Regeneron Pharmaceuticals v. Merus N.V., [16-1346] the Federal Circuit denied rehearing and rehearing en banc the July panel decision, previously discussed here, that litigation misconduct warranted a finding of inequitable conduct in patent prosecution.

Judge Newman, who is usually spot-on in her analysis, again dissented, voicing her concern that inequitable conduct in patent prosecution can be retrospectively imposed by “adverse inference” arising from later misconduct in litigation, without a showing of deceptive intent, which she called “a disservice to the patent practitioner, the patentee, and the public.”

While it would be disturbing if the subsequent unrelated conduct of a litigator could retroactively change the nature of the conduct of the patent prosecutors, this is not the case in Regeneron.  The litigation conduct in question related to resisting disclosures about the alleged inequitable conduct.  If a party is not forthcoming about accused conduct, it seems reasonable to assume that there was something wrong with that conduct.

If Regeneron is used to transmute litigation misconduct into prosecution misconduct, then Judge Newman is right that this is a disservice to patentee and their prosecutors.  However, if Regeneron simply means that if you try to hide prosecution conduct, then the courts will presume you had something to hide, the rule should not be a threat to patent owners and their counsel.