What happens if there is no presumption of nexus in a patent case?

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.

Even if there is no presumption of nexus in a patent case, the patent owner still has an opportunity to prove nexus. The MPEP states, Even if there is no presumption of nexus, the consideration of the rebuttal evidence does not end. ‘To the contrary, the patent owner is still afforded an opportunity to prove nexus by showing that the evidence of secondary considerations is the ‘direct result of the unique characteristics of the claimed invention.’ (MPEP 716.01(b))

In such cases, the patent owner must demonstrate that the secondary considerations are directly related to the unique aspects of the claimed invention, rather than features already present in the prior art.