A Typo to Remember: Erroneous Patent Number in Terminal Disclaimer Destroys Exclusive Rights

Co-authored by Sam Cohen, Summer Associate 2024.

On May 29, 2024, the Western District of Oklahoma in SIPCO, LLC v. JASCO Prods. Co. dismissed the plaintiff SIPCO’s patent infringement claims against defendant JASCO because of a minor typo made by the USPTO during prosecution. The decision, penned by Judge Wyrick, emphasizes the foundational element of public notice within the patent system, balanced against the equally important role of terminal disclaimers in preventing the unfair timewise extension of patent rights. 

Under the doctrine of obviousness-type double patenting, the USPTO routinely rejects patent applications if the claims are obvious variations to claims in a prior patent. This prevents inventors from unjustly expanding their exclusive rights to cover an obvious variant of earlier-filed patent applications. If, however, the inventor owns both the conflicting patent and the application, filing a terminal disclaimer to the application provides an escape hatch from a double patenting rejection. The terminal disclaimer relinquishes to the public any additional time that the later-filed application might otherwise enjoy, preventing an unfair extension of exclusivity over the same core invention. Importantly for this case, an effective terminal disclaimer requires the applicant to own both the application and the specific patent identified in the disclaimer.

But what happens if the USPTO names the wrong patent in an obviousness-type double patenting rejection? Should the patent applicant, duplicating the error in its terminal disclaimer filing, suffer any consequences from propagating the error? In short, Judge Wyrick answered, yes. 

By way of context, SIPCO sued JASCO for infringing the asserted ’304 patent; JASCO promptly filed a 12(b)(6) motion to dismiss on the grounds that the ’304 patent was invalid. When SIPCO initially filed the application that led to the ’304 patent, the USPTO issued an obviousness-type double patenting rejection in view of a ’267 Patent. To overcome the rejection, SIPCO filed a terminal disclaimer, claiming to be the owner of the ’267 Patent and agreeing that the later-issued ’304 patent would only be valid and enforceable for so long as SIPCO owned both the ’304 and the ’267 patents. The problem was SIPCO never owned the ’267 patent: it owned the ’268 patent. The USPTO changed one digit in naming the patent in its double patenting rejection and SIPCO neither caught nor corrected the error. 

In its motion to dismiss, JASCO argued that, because SIPCO never owned the erroneously identified and disclaimed ’267 patent, the ’304 patent had never been enforceable from the moment it issued. Judge Wyrick agreed, concluding that SIPCO should bear severe consequences of the error. He pointed first to the “binding and public nature of the terminal disclaimer promise,” edified by a strict reading of the disclaimer correction rules (MPEP § 1490 VII.B). SIPCO argued in vain that there was no public notice issued because the mistake would be readily identifiable to the public as the ’267 and ’268 patents were not in the same family and covered different technology. As a result, SIPCO contended, there was (1) no prejudice to other entrants to the market and (2) never any risk of unfair timewise extension of patent rights. While Judge Wyrick conceded that there likely was no unfair timewise extension, he flatly rejected the suggestion that there was no public notice concern. Fundamental to patent rights, he explained, is the right of the public “to rely on a patent’s file to understand the full scope of the monopoly.” By failing to identify and correct the USPTO’s initial mistake, SIPCO violated the public’s right of accurate notice. 

Two important threads appear to underly this conclusion. First, because the mistake was easy to spot, the court was not inclined to allow SIPCO to avoid the consequences of its failure to catch an error that should have been readily caught and cured. In other words, it was largely a problem of the patent owner’s own making. Second, strictly observing public notice principles and avoiding unfair timewise extensions of patent rights are equally fundamental to the patent system. The undercurrent in SIPCO’s argument was that the temporal concerns of terminal disclaimer should outweigh the importance of public notice. Not so—at least because innovators and competitors must be permitted to understand the full landscape of relevant patent scope and protection. The interests of the public, at least in this case, outweigh even a mistaken singular digit in a patent number. 

Although this circumstance is likely a rare corner case, more practically the outcome here dramatically underscores the critical importance of attention to detail in prosecution—even one seemingly minor mistake can have catastrophic consequences for the patent owner. Here, one transposed digit in a patent number torpedoed 20 years of protection and stripped a market participant of important exclusive rights over competitors. All this would have been avoided with a spot-check for accuracy of the patent number. 

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