On October 1, 2018, in Natural Alternatives International, Inc. v. Iancu, No. 2017-1962 (Fed. Cir. Oct. 1, 2018), the Federal Circuit held that an amendment to remove priority claims to several parent applications broke the claimed priority chain in a co-pending application and in subsequently filed child applications, thus making the co-pending and later applications vulnerable to invalidity challenges based on former parent applications. Several days after filing a sixth application in a series of applications generally directed to increasing athletes’ endurance, Natural Alternatives International, Inc. (“NAI”) amended the continuation-in-part fifth application to remove a priority claim to the first through fourth applications in the series, in order to gain a longer patent term. The sixth and two additional continuation applications filed by NAI, however, continued to claim priority back through the fifth application to the first application.

On reexamination of the patent issuing from the eighth and final application, the PTO examiner found that NAI’s choice in the fifth application to drop the priority claim to the fourth through first applications meant that the fifth application and any child applications could not claim priority to the fourth through first applications via the fifth application. As a result, NAI’s patent was invalid as anticipated by or obvious over the prior art, including a claimed parent of the NAI patent. The PTAB upheld the examiner’s decision.

On appeal, the Federal Circuit affirmed, explaining that patent claims “are not entitled to an earlier priority date merely because the patentee claims priority,” but rather the “patentee must demonstrate that the claims meet the requirements of 35 U.S.C. § 120.” Slip op. at 8 (quoting In re NTP, Inc., 654 F.3d 1268, 1276 (Fed. Cir. 2011)). Here, “because the fifth application lacked priority to the first application, the eighth application’s priority claim to the first application (via the fifth application) did not satisfy all of § 120’s requirements.” Id. at 10. The court further rejected NAI’s arguments that (1) a waived priority claim is limited to the application in which the waiver occurs and (2) each application in a chain has its own fixed priority chain as opposed to there being a single growing priority chain across all applications. Finally, the court rejected NAI’s attempt to gain additional patent term for its fifth application by waiving its priority claim, while simultaneously shielding later child applications from being held invalid by their former parents by reasserting claims of priority.

What This Means for You

Patent applicants should understand the effect that waiving priority claims in one application could have on child applications. Continuation-in-part applications reciting new matter may receive longer patent terms as a result of disclaiming the priority benefit of earlier applications, but if additional continuation applications that will claim priority to the earlier applications are contemplated, applicants should consider filing those as separate continuations of the earlier applications, rather than continuations of the continuation-in-part. Otherwise, losing the earlier priority date will make those later applications vulnerable to additional prior art, including former parent applications. Perhaps the result might have differed if NAI had kept a separate chain of continuation applications pending, and claimed priority to that chain, instead of choosing to drop the priority claims in the fifth application and then trying to claim priority back through that fifth application.