Inequitable conduct is a defense against an infringement charge. If proven, the patent would destroyed.

Patent attorneys, inventors and others who are involved in granting of or prosecution of a patent application must be open and forthcoming about facts when communicating with the U.S. Patent & Trademark Office.

Inequitable conduct may lead to a judgment that the patent is "unenforceable."

The Federal Circuit in Star Scientific, Inc. v. R.J. Reynolds Tobacco Co., 537 F.3d at 1357, 1365 (Fed. Cir. 2008) held that a party alleging inequitable conduct must prove by clear and convincing evidence:

  1. someone made an affirmative misrepresentation of material fact, failed to disclose material information, or submitted false material information; and
  2. intended to deceive the PTO.[source]