Federal Circuit “Corrects” Antecedent Basis, Reversing District Court’s Indefiniteness Ruling

In Canatex Completion Sols., Inc. v. Wellmatics, LLC, No. 2024-1466 (Fed. Cir. Nov. 12, 2025), the Federal Circuit reversed and remanded a district court decision finding Canatex’s asserted claims invalid for indefiniteness.  

Canatex sought to enforce U.S. Patent No. 10,794,122 (the ’122 patent), which is directed to a device used in oil and gas wells that is comprised of two parts. Representative claim 1 of the ’122 patent recites, “the connection profile of the second part” without prior reference to that limitation, prompting the district court to rule the claims indefinite for lack of antecedent basis.

Acknowledging the demanding standard for judicial correction, the Federal Circuit reversed, finding that while the claims contain an error, a relevant artisan would recognize that there is only one correction that is reasonable given the intrinsic evidence. In doing so, the Court adopted Canatex’s claim construction that the claim language should read, “the connection profile of the first part,” fixing the antecedent basis to the previously recited, “a first part comprising an external connection profile” in the claim language. The Court held that this correction was supported by the written description, the figures and their descriptions, including the lack of evidence of a connection profile of the second part, as originally claimed.