How does the breadth of a prior art range affect obviousness determinations?

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.

The breadth of a prior art range can significantly impact obviousness determinations in patent law. According to MPEP 2144.05:

“One factor that may weigh against maintaining an obviousness rejection based on optimization of a variable disclosed in a range in the prior art is where an applicant establishes that the prior art disclosure of the variable is within a range that is so broad in light of the dissimilar characteristics of the members of the range as to not invite optimization by one of skill in the art.”

This principle is based on the case Genetics Inst., LLC v. Novartis Vaccines & Diagnostics, Inc., where the court held that ordinary motivation to optimize did not apply to a very broad range of protein variants.

However, it’s important to note that a prior art range that merely overlaps or encompasses a claimed range can still establish a prima facie case of obviousness. The key is whether the range is so broad as to not invite optimization by a person of ordinary skill in the art.