The US Court of Appeals for the Federal Circuit vacated a district court’s grant of summary judgment on inequitable conduct and a Walker Process antitrust claim arising from allegations that a patent owner withheld material prior art during patent prosecution and sought to enforce the patents against a competitor in the coiled tubing market. Global Tubing v. Tenaris Coiled Tubes, Case Nos. 23-1882; -1883 (Fed. Cir. Feb. 26, 2026) (Taranto, Hughes, Stark, JJ.)
Global Tubing filed a declaratory judgment action seeking a ruling that its coiled tubing product did not infringe Tenaris’ patents. After uncovering a document in discovery that it characterized as evidence that Tenaris attempted to withhold material information during patent prosecution, Global Tubing amended its complaint to assert inequitable conduct and Walker Process fraud, alleging that Tenaris sought to use fraudulently obtained patents to monopolize the market. Following the completion of discovery, the parties filed cross-motions for summary judgment. The district court granted summary judgment of inequitable conduct to Global Tubing and summary judgment of no liability for Walker Process fraud to Tenaris. As to the Walker Process fraud claim, the court determined that because Tenaris was such a small market player, Global Tubing could not prove it had the market power sufficient to achieve a monopoly. Both parties appealed.
The Federal Circuit determined that the district court erred in granting summary judgment to Global Tubing, finding that genuine disputes of material fact remained as to whether the single most reasonable inference was that the inventor acted with specific intent to deceive the United States Patent and Trademark Office (USPTO), making summary judgment on inequitable conduct inappropriate.
Addressing the Walker Process fraud claim, the Federal Circuit likewise vacated the district court’s grant of summary judgment in favor of Tenaris, finding that the record contained genuine disputes of material fact that precluded judgment as a matter of law. The Court explained that the evidence could support a finding that the inventor knowingly withheld a material prior art reference from the USPTO with intent to deceive, and that Global Tubing had raised a triable issue as to the first prong of its Walker Process claim: whether Tenaris obtained and enforced the patent through knowing and willful fraud on the USPTO.
Turning to the second prong of a Walker Process fraud claim (attempted monopolization), the Federal Circuit observed that the parties advanced competing definitions of the relevant market. The Court concluded that the district court erred by characterizing Tenaris as a small market participant with no dangerous probability of achieving monopoly power without first defining the relevant product and geographic markets or determining whether genuine disputes of material fact existed on those issues.
The Federal Circuit also concluded that genuine disputes of material fact remained as to whether Tenaris engaged in predatory or otherwise anticompetitive conduct. The Court noted that there may have been a triable issue regarding the appropriate date at which to measure Tenaris’ share of the relevant yet undefined market. Considering these unresolved factual questions, the Court determined that summary judgment on Global Tubing’s Walker Process claim was improper.




