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 DRL failed to demonstrate unpatentability of claim 8.

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

Claim 1about 40 wt % to about 60 wt %
Claim 7about 48.2 wt % to about 58.6 wt %
Claim 8about 48.2 wt %
Claim 12about 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.

Lack of Showing of Criticality Dooms Claims with Ranges Overlapping the Prior Art

Genentech, Inc., v. Hospira, Inc., [2018-1933] (January 10, 2020), the Federal Circuit affirmed the PTAB holding claims 1–3 and 5–11 of U.S. Patent 7,807,799 directed to methods of purifying certain antibodies and other proteins unpatentable as anticipated or obvious.

Important to the invention was operating at a low temperature to eliminate the need for subsequent purification steps, the claims specified a range of “about 10°C to about 18°C”, which the Federal Circuit found overlapped the prior art range of “18–25°C,” regardless of the construction of “about 18°C.” The Federal Circuited noted that the patentee own proposed construction for “about 18°C” embraces temperatures up to 19°C, which further reinforces the overlap with the prior art’s disclosed temperature range.

The Federal Circuit said a prior art reference that discloses an overlapping but different range than the claimed range can be anticipatory, even where the prior art range only partially or slightly overlaps with the claimed range.  Once a patent challenger has established, through overlapping ranges, its prima facie case of anticipation, the court must evaluate whether the patentee has established that the claimed range is critical to the operability of the claimed invention.  The Federal Circuit found that the the patentee failed to show criticality of the range.

As to obviousness, the Federal Circuit noted that even a slight overlap in range establishes a prima facie case of obviousness, and that the burden of production falls upon the patentee to come forward with pertinent evidence that the overlapping range would not have been obvious in light of the prior art.  One way in which the patentee may rebut the presumption of obviousness is by showing that there is some-thing special or critical about the claimed range.  The Federal Circuit found that presumption of obviousness applies here, and the Board found that Genentech failed to establish criticality for the claimed temperature range, which Genentech did not appeal. The Federal Circuit said that another way in which the presumption can be rebutted is by showing that a process parameter, such as temperature, was not recognized as “result-effective.”  However, Federal Circuit said that the Board reasonably found that a skilled artisan would have been motivated to optimize the temperature given the teachings of the prior art, and that given the ease with which temperature can be varied, finding an optimal temperature range would have been nothing more than routine experimentation.