How does prior publication affect joint inventorship?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

Prior publication of a joint inventor’s contribution does not necessarily negate joint inventorship. The MPEP cites the case Dana-Farber Cancer Inst., Inc. v. Ono Pharm. Co., which states:

“[A] collaborative enterprise is not negated by a joint inventor disclosing ideas less than the total invention to others, especially when, as here, the collaborators had worked together for around one year prior to the disclosure, and the disclosure occurred just a few weeks prior to conception.”

This means that in collaborative inventions, partial disclosures by one inventor prior to the complete conception of the invention may not disqualify joint inventorship, particularly if there’s an established history of collaboration.