What are the estoppel effects of inter partes reexamination?

What are the estoppel effects of inter partes reexamination?

Inter partes reexamination has significant estoppel effects that can impact future proceedings. The MPEP explains: “A third party requester is estopped from later asserting in any civil action, or in a subsequent inter partes reexamination, the invalidity/unpatentability of any claim finally determined to be valid and patentable on any ground the third party requester raised or could have raised during the inter partes reexamination proceedings.” (MPEP 2686) This means that:

• The estoppel applies to grounds actually raised during the reexamination.
• It also covers grounds that could have been raised but weren’t.
• The estoppel affects both future civil actions and subsequent inter partes reexaminations.
• It only applies to claims finally determined to be valid and patentable.

These estoppel provisions are designed to prevent repeated challenges on the same grounds and encourage parties to bring all relevant issues forward during the reexamination process.

To learn more:

• inter partes reexamination
• estoppel effects
• patent validity