Proving Inequitable Conduct in Patent Prosecution: A Comprehensive Guide

63 questions on proving inequitable conduct in patent prosecution, answered and cited by the UpLaw editorial team.

• Can a reference be material without being invalidating?
• Can intent be proved with only circumstantial evidence?
• Does the attorney-client privilege block the key documents?
• From whose vantage point is materiality judged?
• How does a strawman comparison become a false-declaration case?
• How does supplemental examination cure a prosecution defect?
• How does the crime-fraud bootstrap work?
• How does the privilege log become the key to the intent case?
• How does the trial presentation assemble the two elements?
• How do foreign counterparts and post-grant proceedings serve as comparison engines?
• How do local patent rules affect the timing of an inequitable-conduct theory?
• How do the two burdens of proof differ at trial?
• How do unclean hands and patent misuse travel alongside inequitable conduct?
• How is inequitable conduct different from invalidity?
• How is inequitable conduct tried, and how is it reviewed on appeal?
• How is intent built from a constellation rather than a single star?
• How is materiality proved for a specific limitation?
• How much intent must a complaint show, and where do courts split?
• Is there a duty to search for prior art?
• What are the patent owner's four litigation defenses?
• What can a PTO-practice expert do, and where are courts wary?
• What can assignment records expose?
• What can requests for admission lock down?
• What contradictions between the patent and the outside world should you chase?
• What did Therasense kill, and why does it reshape the investigation?
• What does a compliant pleading look like in practice?
• What does the pre-suit public-records investigation actually turn up?
• What downstream consequences follow a loss on inequitable conduct?
• What downstream remedies does a fraud finding set in motion?
• What four things must an Exergen-compliant pleading do?
• What four things should an IDS review interrogate?
• What happens to the patent owner if it loses on inequitable conduct?
• What is a prosecution bar, and why does it cut both ways?
• What is the affirmative-egregious-misconduct shortcut?
• What is the best prophylactic defense for a patent owner?
• What is the classic trans-Atlantic mismatch fact pattern?
• What is the good-faith-explanation asymmetry?
• What is the Regeneron adverse-inference route?
• What is the single-most-reasonable-inference wall?
• What is the through-line of proving inequitable conduct?
• What lane must a technical expert stay in?
• What should interrogatories ask, and how should they be drafted?
• What three questions should you ask of every office-action response?
• What three steps does Therasense require?
• What tools work against the privilege wall?
• What two practical realities shape depositions in these cases?
• What two things in the file wrapper matter above all others?
• When must interested-witness testimony be corroborated?
• Where does intent usually hide?
• Which document categories are most productive?
• Who enforces the duty of candor?
• Who owes the duty of candor to the USPTO?
• Why are sworn declarations the richest vein of evidence?
• Why does Rule 9(b) govern inequitable-conduct pleading?
• Why does the file wrapper come first in the evidence map?
• Why do IDS timing rules generate testable evidence?
• Why do the regulation and the case law define materiality differently?
• Why is cumulativeness the central materiality battleground?
• Why is inequitable conduct different in kind from other patent defenses?
• Why is knowledge of materiality, not mere existence, the discovery target?
• Why is summary judgment of inequitable conduct rare?
• Why is unclean hands a valuable fallback?
• Why request documents that are likely privileged?