The Other Side Of The Coin: Diligent Patent Prosecution Does Not Lead To Unreasonable Delay And Application Of Prosecution Laches

• Published date: 25 July 2022
• Subject Matter: Intellectual Property, Patent
• Law Firm: Duane Morris LLP
• Author: Ms Deborah L. Lu, Ph.D., Thomas J. Kowalski and Brandon A. Chan, Ph.D.

The backlog of pending patent applications at the USPTO is growing. As of May 2022, the USPTO estimates an average pendency of approximately 20 months from filing to the mailing of a first office action, which is an increase of three months from the average pendency from the prior year. (An average pendency of 17 months in May 2021 can be seen on the USPTO website by clicking the "View the last two years chart" button.) Because of this nearly two-year average pendency, applicants may be tempted to take advantage of and exploit the patent system to unreasonably delay prosecution and extend the patent term of a patent family member far beyond the lifetime of the original parent application. This strategy may have been especially common prior to the USPTO's June 8, 1995, implementation of rules under the General Agreement on Tariffs and Trade (GATT). These rules resulted from the 1994 signing of the Uruguay Round Agreements Act, whereby applications filed prior to June 8, 1995, have their patent terms expire 17 years from the issue date and the patent terms for applications filed on or after June 8, 1995, expire 20 years from the filing date of the earliest application to which priority is claimed. In view of the patent term adjustment (PTA) for post-GATT patents, applicants still may be tempted to exploit prosecution delays?especially if they can be said to be caused by the USPTO?and add to the patent term via PTA. In addition, in this post-GATT environment, patent applicants may be tempted to keep an application in a patent family during the 20-year patent term pending to introduce claims based thereon when a market develops and a competitor designs around granted claims but possibly still within the original disclosure.

To prevent this gaming of the patent system in the hopes of extending patent term and to prevent prejudice to others, the equitable affirmative defense of prosecution laches may be raised to render an asserted patent unenforceable. Although raising the defense of prosecution laches is relatively uncommon, prosecution laches has attracted attention in two recent cases: Hyatt v. Hirshfeld, 998 F.3d 1347 (Fed. Cir. 2021) and Personalized Media Communications, LLC v. Apple, Inc., 552 F. Supp. 3d 664 (E.D. Tex. 2021) (PMC). The courts in both Hyatt and PMC, involving patents claiming priority to pre-GATT applications, held that there was unreasonable delay in prosecution and prejudice?the former vacating the district court's determination that...