How does estoppel on the merits work in patent interference cases?

Estoppel on the merits in patent interference cases prevents a losing party from seeking claims that are anticipated or obvious based on the subject matter of the lost count. According to MPEP 2308.03:

“A losing party is barred on the merits from seeking a claim that would have been anticipated or rendered obvious by the subject matter of the lost count.”

This means that if an applicant loses on priority for a specific subject matter, they cannot later claim that same subject matter or obvious variations of it. For example, if an applicant loses on a count drawn to subject matter X, they cannot file a continuing application with a claim to subject matter X or a claim that would be obvious in view of X.

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Topics: MPEP 2300 - Interference And Derivation Proceedings, MPEP 2308.03 - Estoppel Within The Office, Patent Law, Patent Procedure
Tags: Estoppel On The Merits, MPEP, Patent Interference, USPTO