Skip to Main Content
Blog

Federal Circuit Allows Immediate Appeal of Denial of Anti-SLAPP Motion Under Collateral Order Doctrine

10.21.25
Page Graphic

Last week, the U.S. Court of Appeals for the Federal Circuit issued a precedential opinion in IQE plc v. Newport Fab, LLC, et al., No. 24-1124 (Oct. 15, 2025), vacating the Central District of California’s denial of Defendants’ motion to strike California state-law claims of trade secret misappropriation and interference with economic opportunity under California laws that seek to limit Strategic Lawsuits Against Public Participation (SLAPP).

IQE developed porous silicon technology and entered a non-disclosure agreement with Defendants for a potential collaboration involving the technology in semi-conductor products. Defendants filed patent applications during and after these discussions. IQE alleged Defendants’ patent applications described IQE's porous semi-conductor technology, derived from trade secrets disclosed during negotiations.

IQE sued alleging various claims, including intentional interference with prospective economic advantage and California trade secret misappropriation. Defendants filed an anti-SLAPP motion to strike these two claims, and the district court denied the motion. Defendants immediately appealed the ruling to the Ninth Circuit, which determined that the Federal Circuit had jurisdiction and transferred the appeal pursuant to 28 U.S.C. § 1631.

The Federal Circuit held that it had subject matter jurisdiction over the appeal because the underlying action included a 35 U.S.C. § 256 claim (correction of inventorship) arising under federal patent law. The Court further held that, under Federal Circuit law, the denial of an anti-SLAPP motion brought under California’s anti-SLAPP law is immediately appealable under the collateral order doctrine because such denials conclusively determine the anti-SLAPP issue, protect constitutional rights, and would be effectively unreviewable if Defendants were forced to litigate to final judgment before appealing, resulting in loss of the statutory protection. Finally, the Court held the district court erred in its consideration of Defendants’ anti-SLAPP motion because the “question for the district court at step one should have been only whether the suit was based on protected activity,” and the activity in question—the filing of a patent application—is clearly protected activity. The Court explained that the district court’s assessment of the merits of IQE’s claims should have been reserved for the step two analysis, wherein the burden shifts to the plaintiff to establish a reasonable probability that it will prevail on its claim. The Court thus vacated and remanded to the district court to consider step two of the anti-SLAPP motion.