Affirming a Patent Trial and Appeal Board (PTAB) priority determination invalidating a patent, the US Court of Appeals for the Federal Circuit found that amending the priority claim of a parent application to delete a reference to earlier-filed applications affected the priority claim of the child application, making the earlier applications prior art. Natural Alternatives International, Inc. v. Iancu, Case No. 17-1962 (Fed. Cir. Oct. 1, 2018) (Prost, CJ).

Natural Alternatives International (NAI) filed a chain of eight patent applications. In each continuing application, NAI claimed priority to the first application under 35 USC § 120 through the prior applications. During the pendency of the fourth application, NAI filed a new provisional application. When filing the fifth application in the chain—a continuation-in-part application—NAI claimed the benefit of both the first four continuing applications and the new provisional application. Shortly after filing its sixth application, NAI amended the priority of its fifth application by deleting its priority claim to the first through fourth applications and retained benefit only to the provisional application under 35 USC § 119(e). The priority claims of the sixth through eighth applications were not amended; these applications eventually issued, claiming priority to the first five applications and the provisional application. The patent at issue in this case is the eighth patent in the chain.

Woodbolt Distributors requested that the US Patent and Trademark Office (PTO) re-examine NAI’s eighth patent, alleging that the priority claim of the patent was defective. The PTO instituted inter partes re-examination, and the PTAB affirmed the examiner’s conclusion that the challenged claims of the eighth patent were anticipated or obvious over the cited prior art because the eighth patent was not entitled to the benefit of the first application’s filing date since NAI deliberately deleted the specific reference to the earlier applications in the fifth application. NAI appealed.

On appeal, NAI argued that:

  • Priority to the first application “vested” with the sixth application once the sixth application met all the criteria of § 120.
  • Waiver of priority is limited to the intervening application in which priority was waived (in this case the fifth application) and does not extend to subsequent applications.
  • The PTAB erroneously viewed priority as a single growing chain rather than multiple fixed chains.
  • The PTAB’s view of priority claims limits an applicant’s ability to amend a priority claim to gain patent term.

The Federal Circuit found that NAI’s “vesting” argument conflated properly claiming priority with demonstrating entitlement to priority, and noted that patent claims “are not entitled to an earlier priority date merely because the patentee claims priority.” Citing the Manual of Patent Examining Procedure (MPEP) § 201.11, the Court noted that, contrary to NAI’s argument, nothing in MPEP’s text limits the scope of a waiver of priority to only the instant application. The Court also declined to adopt NAI’s interpretation of chain of priority as multiple fixed chains, reasoning that the long-standing interpretation of priority has been viewed as a single chain, growing with each additional continuation.

Finally, the Federal Circuit noted that NAI’s final argument suggests that NAI does need not to trade the benefit of an earlier filing date in order to gain patent term. The Court found that under NAI’s theory, a patentee could gain patent term on its earlier application by deleting a priority claim while simultaneously shielding its subsequent child applications (e.g., the eighth application in NAI’s case) from the parents being cited as prior art. The Court concluded that a patentee cannot have it both ways.