November 24, 2021

To Claim a Range, Make it Clear You are a Claiming a Range

In Indivior UK Limited v. Dr. Reddy’s Laboratories S.A., [2020-2073, 2020-2142] (November 24, 2021), the Federal Circuit affirmed the PTAB’s decision in an IPR that claims 1–5, 7, and 9–14 are unpatentable, and that Dr. Reddy’s Laboratories (DRL) failed to demonstrate unpatentability of claim 8.

The ’454 patent, which generally describes orally dissolvable films containing therapeutic agents, issued as the fifth continuation of U.S. Patent Application 12/537,571 filed on August 7, 2009.

This appeal involves the question whether Indivior can get the benefit of that 2009 filing date for the claims of the ‘454 patent, and in particular support for the claimed ranges:

Claims Range
Claim 1 About 40 wt % to about 60 wt %
Claim 7 About 48.2 wt % to about 58.6 wt %
Claim 8 About 48.2 wt %
Claim 12 About about 48.2 wt % to about 58.6 wt %


Invidior pointed out that Tables 1 and 5 of the ‘571 application disclose formulations with 48.2 wt % and 58.6 wt % polymer, and discloses that “the film composition contains a film forming polymer in an amount of at least 25% by weight of the composition.” Indivior argued that the combination of these disclosures encompasses the claimed ranges, and therefore provides a written description of them. DRL contended that a skilled artisan would not have discerned the claimed ranges because the ’571 application does not disclose any bounded range, only a lower endpoint and some exemplary formulations. DRL contended that a skilled artisan would not have discerned any upper range endpoint.

Regarding claim 1, the Federal Circuit agreed with the Board that there was no written description support in the ’571 application for the range of “about 40 wt % to about 60 wt %,” noting that the range was not expressly claimed in the ’571 application; and that the values of “40 wt %” and “60 wt %” are not stated in the ’571 application.

Regarding claims 7 and 12, the Federal Circuit also agreed with the Board that there is no written description support for the range of “about 48.2 wt % to about 58.6 wt %” in the ’571 application, noting that this range also does not appear in the ’571 application. While the endpoints of this “range” could be discerned from the Tables, the Federal Circuit said that constructing a range from this data “amounts to cobbling together numbers after the fact.” The Federal Circuit said that Indivior failed to provide persuasive evidence demonstrating that a person of ordinary skill would have understood from reading the ’571 application that it disclosed an invention with a range of 48.2 wt % to 58.6 wt %.

Because Indivior did not contest that the claims would be anticipated without the benefit of the 2009 filing date, the court affirmed the invaldity of the challenged claims, except claim 8, whose single data point was supported by the disclosure of the ‘571 patent.


This result is of course concerning to chemical practitioners who have or may one day fine the need to construct a range from disclosed datapoints. The Federal Circuit’s assurances that each case is fact specific is of little comfort if one find themselves in this predicament.

The bottom line is if ranges are intended, ranges should be mentioned. It is unlikely that Invidior ever contemplated that the invention only worked at selected points, and not in between, Invidior apparently needed to make explicit what it thought was implicit. The issue in Invidior is not a problem in claiming ranges, but a problem in making clear that you are claiming ranges.