Introduction: The Perilous Tightrope of Patent Prosecution

Imagine spending years and millions of dollars securing a patent, only to have it vaporized in court because someone forgot to mention a critical piece of prior art. Welcome to the world of inequitable conduct—a doctrine so potent it’s been dubbed the “atomic bomb” of patent law. This blog post will dissect this high-stakes defense, blending legal rigor with practical advice (and a dash of humor) to guide inventors and attorneys through the minefield of USPTO candor requirements.

Part 1: What Is Inequitable Conduct?

Inequitable conduct occurs when a patent applicant breaches their duty of candor by withholding material information or making false statements to the USPTO with the intent to deceive. The consequences? A nuclear option: unenforceability of the entire patent, even if only one claim was tainted.

Key Elements

1. Materiality: The information must be “but-for” material—i.e., the USPTO would not have allowed the claim had it known.
   • Example: In Therasense Inc. v. Becton Dickinson, a withheld prior art reference that anticipated the patent’s claims was deemed material.
2. Intent to Deceive: Not mere negligence, but deliberate action. Courts infer intent from circumstantial evidence, but it must be the “single most reasonable inference”.

Pro Tip: Think of inequitable conduct like hiding a zombie in your basement during a real estate sale. Sure, the house looks great, but once the buyer finds the undead tenant, the whole deal collapses.

Part 2: The Therasense Earthquake

The 2011 Therasense decision reshaped the landscape by tightening standards to curb frivolous allegations. No longer can a “sliding scale” let weak intent ride on strong materiality. Now, both must be proven separately, with exceptions only for egregious misconduct (e.g., forged affidavits).

Impact: Post-Therasense, accused infringers face a higher bar, but the defense remains potent. For example, in Regeneron v. Merus, litigation misconduct (like withholding documents) was used to infer deceptive intent during prosecution.

Part 3: Common Pitfalls & Case Studies

1. Prior Art Shenanigans

• McKesson v. Bridge Medical: Failure to disclose office actions from related applications led to unenforceability.
• Semiconductor Energy Lab: Submitting partial translations of Japanese patents while omitting key sections was deemed deceptive.

2. Inventorship Blunders

In PerSeptive Biosystems, misrepresenting contributions to obfuscate inventorship triggered unenforceability.

3. Litigation Mischief

Regeneron’s “pattern of misconduct” in court—like ignoring court orders—fueled inferences of intent to deceive the USPTO.

Takeaway: The USPTO isn’t Ocean’s Eleven. Leave the scheming to Hollywood.

Part 4: Infectious Unenforceability—When One Bad Apple Spoils the Bunch

In Guardant Health v. Foundation Medicine, the court upheld “infectious unenforceability,” ruling that misconduct in one patent can taint related patents if they share an “immediate and necessary relation”.

Lesson: Patent families are like sitcom families—drama in one episode can haunt the whole series.

Part 5: Practical Survival Guide

For Attorneys

• Disclose, Disclose, Disclose: When in doubt, throw it out (to the examiner). Even marginally relevant art is safer than a costly omission.
• Avoid “Burying”: Don’t hide critical references in a haystack of prior art. Highlight key documents.
• Document Everything: Create a paper trail showing good faith. If you debate materiality internally, note it—courts love evidence of diligence.

For Inventors

• Speak Up: Tell your attorney about all prior art, sales, or testing—even failed experiments.
• Beware Translations: If you have a partial translation of a foreign reference, submit it and flag its limitations.

Pro Tip: Prosecuting a patent is like online dating. Full transparency might not be glamorous, but catfishing the USPTO ends in disaster.

Part 6: The Future of Inequitable Conduct

While Therasense raised the bar, critics argue the doctrine’s strict standards undercut its role as a deterrent. With the rise of AI-assisted prior art searches and global patent filings, the duty of candor will only grow more complex.

Final Thought: In the words of Judge Bryson, without inequitable conduct, we’d have “no effective deterrent” against patent subterfuge. Balance candor with strategy, and remember: patents are a public contract. Dishonesty voids the warranty.

Need Help Navigating Patent Prosecution?
Contact [Law Firm Name] for a candor audit of your portfolio. Because nobody wants their patent to go nuclear.

© [Year] [Law Firm Name]. This article is for informational purposes only and does not constitute legal advice. [Witty disclaimer about not hiding prior art here.]

Citations: [1][2][3][4][5][6][7][8][9][10]