The Federal Circuit's decision in Medtronic CoreValve, LLC v. Edwards Lifesciences Corp. provides a warning for patent practitioners seeking to claim priority to earlier filed patent applications:  failure to specifically reference each earlier filed patent application will result in a loss of a claim to priority to the omitted application(s).

Medtronic sued Edwards for infringement of certain claims of its patent for a prosthetic valve, U.S. Patent No. 7,892,281 (the '281 patent).  The'281 patent was filed on January 5, 2009 and descends from a number of United States, international, and French patent applications.  Medtronic's position was that the asserted claims of the '281 patent had a priority date of October 31, 2000.

During litigation in the U.S. District Court for the Central District of California, Edwards realized that the priority chain for the '281 patent did not comply with the requirements of 35 U.S.C. §§ 119 and 120 and moved for partial summary judgment that this limited the priority date of the asserted claims of the '281 patent to no earlier than April 10, 2003.  Medtronic filed a cross-motion for summary judgment, arguing that the asserted claims were entitled to the priority date of October 31, 2000.

The District Court held that the '281 patent was not entitled to a priority date prior to April 10, 2003 because various applications in the chain of priority were not in compliance with the requirements of claiming priority under either 35 U.S.C. §§ 119 or 120.  The District Court thus granted Edwards' motion for summary judgment.  Medtronic appealed the priority issue to the Federal Circuit.

The priority issue under 35 U.S.C. § 120 was whether the '281 patent "contains or is amended to contain a specific reference to the earlier filed application . . . submitted at such time during the pendency of the application."  35 U.S.C. § 120.  The Federal Circuit previously held in another case that the "specific reference" requirement means that each intermediate application in the chain of priority to refers to the prior applications.  Encyclopaedia Britannica, Inc. v. Alpine Electronics of America, Inc., 609 F.3d 1345, 1352 (Fed. Cir. 2010).

Although the application for the '281 patent properly claimed the entire chain of priority, certain U.S.  applications in the chain of priority were held by the Federal Circuit to fail to specifically reference earlier filed applications.  At issue were two applications that simply stated "this application is also a continuation-in-part of [the international application]."  Medtronic argued that "this application" referred to an intervening application in the priority chain and thus did not leave out the intervening application, whereas Edwards argued that "this application" had a plain language meaning and referred to the present application, thus leaving out the intervening application.

The Federal Circuit agreed with Edwards and held that the term "this application" is to have its plain language meaning, consistent with Section 201.11 of the M.P.E.P., to refer self-referentially to the present application.  Medtronic argued that the reasonable person test should instead be applied; however, the Federal Circuit held that "the patentee is the person best suited to understand the genealogy and relationship of her applications; a requirement for her to clearly disclose this information should present no hardship . . . .  Medtronic's 'reasonable person' test improperly places the burden of deciphering a priority claim upon the reader or the public."  The Federal Circuit agreed with the District Court and held that the two applications at issue thus lost any priority claim prior to April 10, 2003, and thereby also ruined a claim to priority before April 10, 2003 for the '281 application.

The loss of claim of priority that limited the asserted claims of the '281 patent to the April 10, 2003 priority date resulted in the asserted claims of the '281 patent being held invalid as anticipated under 35 U.S.C. § 102 with two of the earlier filed applications listed in the '281 patent's chain of priority.

Medtronic CoreValve, LLC v. Edwards Lifesciences Corp. (Fed. Cir. 2014)
Panel: Circuit Judges Prost, Plager, and Taranto
Opinion by Circuit Judge Prost