Assignor Estoppel: The Current State of the Law

//Assignor Estoppel: The Current State of the Law

Assignor Estoppel: The Current State of the Law

Assignor Estoppel: The Current State of the Law

Confusion can result if agencies and courts address similar legal issues. A case in point is the current muddle over the common law doctrine of assignor estoppel in patent litigation, where disputes over patent validity often proceed in parallel before the USPTO’s Patent Trial and Appeal Board and federal district courts. The doctrine, which prevents an inventor or patent owner who assigns a patent to another party from later challenging the validity of the patent, plays a role in a significant number of high-profile patent disputes. The Federal Circuit gives assignor estoppel a wide scope, while the PTAB has determined that assignor estoppel does not apply to AIAinter partes review (IPR) proceedings.

It appeared as if this conflict might be resolved soon, but that possibility has seemingly evaporated. EVE-USA/Synopsys petitioned the Supreme Court for certiorari, after assignor estoppel was applied against it in its case against Mentor Graphics. The Supreme Court asked for the views of the Solicitor General on the petition. But the parties stipulated to dismissal of the case in July.

Our panelists – two litigators both recently involved in significant cases involving assignor estoppel, as well as in-house counsel at a tech company, will discuss the fluid state of the law. The Federal Circuit in Husky Injection Molding Systems Ltd. v. Athena Automation Ltd. held that it lacked jurisdiction to review the PTAB’s determination that IPR challenges are not barred by assignor estoppel. But that decision relied on Achates, an earlier Federal Circuit decision which the Court has since overturned. The panel will also consider such corporate concerns as inventor mobility and patent sales in light of assignor estoppel.

Speakers:

  • Mark Miller, O’Melveny & Myers LLP
  • Marshall Schmitt, Michael Best & Friedrich LLP
  • Marian Underweiser, IBM Corp.