What does the SFI petition argue?

SFI argues the USPTO is allowing a procedural end-run where challengers can file the same patent challenge in multiple venues (like IPR and then reexamination) to avoid estoppel and create endless review, undermining the goal of finality.

Will this lead to more patent litigation?

Potentially. By prolonging USPTO proceedings, these tactics can also delay parallel district court litigation, giving alleged infringers more time and resources to fight.

Can patent owners stop this?

They can highlight the issue, as SFI has done. The USPTO has the discretion under 35 U.S.C. § 325(d) to deny review of substantially the same prior art or arguments previously presented, but it's currently not exercising that discretion consistently.

©️ IP & Copyright

USPTO's Reexamination Loophole [2026]

They say you don't get a second bite at the apple. Except, apparently, if you're a patent challenger at the USPTO. This isn't strategy; it's structural rot.

Legal AI Beat Apr 12, 2026 4 min read

A gavel striking a sound block on a pile of legal documents, with a faint USPTO seal in the background.

⚡ Key Takeaways

The USPTO is allowing patent challengers to re-file identical arguments through different proceedings (IPR then reexamination) to avoid estoppel and gain multiple bites at the apple. 𝕏
This practice creates significant procedural delay, which benefits alleged infringers and undermines the finality of patent rights. 𝕏
A petition by Security First Innovations (SFI) highlights this structural vulnerability and urges the USPTO to enforce existing statutes like 35 U.S.C. § 325(d). 𝕏