Sweating Bullets Over the Patentability of Ranges

Posted by Cristin Berkey on Apr 18, 2017

If a patent claim recites a range of 2-6 units, and a prior art reference recites a range of up to 4 units, do those two ranges overlap such that the patent claim is not novel? If so, how important are the ranges when it comes to establishing the novelty of the claim, and whose job is it to make that argument? These questions of overlapping ranges arose in Dermira, Inc. v. Purepharm, Inc. (IPR2015-01593). In this IPR decision, the PTAB affirmed that when a reference discloses an overlapping range with the challenged patent’s claims, the patent holder has the burden of showing the criticality of the claimed range to establish novelty.

The patent at issue, US Patent No. 8,679,524 (“the ’524 patent”), is directed to a method of applying glycopyrrolate to reduce excessive sweating. In the method, the glycopyrrolate is topically applied using a pad. The petitioner asserted lack of novelty over the Hays reference, which recites a cotton applicator saturated with 1.0% and up to 4.0% glycopyrrolate solution.

The issue of overlapping ranges arises in dependent claims 9 and 10. Those claims recite ranges of 2.0 wt. % to 6.0 wt. % and 2.0 wt. % to 4.0 wt. %, respectively, whereas Hays recites up to 4.0%. According to the Manual of Patent Examining Procedure, in the case of overlapping ranges, the range in the art is only anticipatory if it is described with “sufficient specificity to constitute an anticipation under the statute.” This is an extremely fact-dependent analysis, and cases vary widely regarding what is meant by “sufficient specificity.”

In Ineos USA LLC v. Berry Plastics Corporation (Fed. Cir. 2015), the court held that when the cited art and the patent-in-suit recite overlapping ranges, the prior art may anticipate. According to the court, “[i]f the prior art discloses its own range, rather than a specific point, then the prior art is only anticipatory if it describes the claimed range with sufficient specificity such that a reasonable fact finder could conclude that there is no reasonable difference in how the invention operates over the ranges.”

The court further found that when there are overlapping ranges, it is up to the patent holder to show the claimed range is critical to the operability of the invention. This is an exception to the general rule in post-grant practice that the burden is on the petitioner to show unpatentability by a preponderance of the evidence. Here, once a threshold showing of overlapping ranges was made, the burden shifted to the patent holder to show the criticality of the claimed range.

The PTAB held that the ranges in dependent claims 9 and 10 of the ’524 patent of 2.0 wt. % to 6.0 wt. % and 2.0 wt. % to 4.0 wt. %, respectively, were anticipated by the Hays reference. This is in accordance with the established precedent, as the patent owner did not assert the criticality of the claimed range.


In claims with ranges, patent holders should consider building into their patent support for the criticality of a range or ranges. This support could aid in preserving the patent when challenged with prior art that discloses overlapping ranges. 

Topics: BioPharma

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