Inequitable conduct is, in my humble opinion, the most disappointing claim. Whenever I see it in a pleading, I have a fleeting moment of excitement—maybe the patentee kidnapped the examiner's dog, maybe hypnotism will play a roll, maybe just a classic honeypot?
But it's never that. 9 times out of 10, its a reference that wasn't disclosed, but it probably should have been disclosed, yadda, yadda, yadda.
Despite the high standard for pleading IC (and how boring I find it), the claim tends to be fairly resilient. A quick look at recent opinions shows that Delaware Courts have denied the last 7 motions for summary of judgment of no inequitable conduct. You have to go all the way back to February of 2022 to find a success (Extang Corp. v. Truck Accessories Group, LLC, C.A. No. 19-923-KAJ (D. Del. Feb. 8, 2022) (Order)).
Judge Williams' decision last month (unsealed last week) in EIS, Inc. v. Intihealth Ger GmbH, C.A. No. 19-1227-GBW (D. Del Aug. 23, 2023), shows just hard it can be to get rid of inequitable conduct. The inequitable conduct claim there was based on the failure to effectively disclose an allegedly material reference. The reference was in a foreign language, but the applicant had only translated the abstract for the examiner.
The plaintiff moved for summary judgment of no inequitable conduct alleging all of the usual grounds—insufficient evidence of intent to deceive, lack of materiality, all the elements. The argument on lack of materiality was particularly strong because ...