Examples in Specification Did Not Provide Written Description Support for Bounded or Closed Ranges

The Federal Circuit Court of Appeals affirmed the Patent Trial and Appeal Board’s determination that a patent specification did not provide written description support for range limitations in the challenged claims. Indivior UK Ltd. v. Reddy’s Labs. S.A., Nos. 2020-2073, 2020-2142, 2021 U.S. App. LEXIS 34959, at *1 (Fed. Cir. Nov. 24, 2021). Where a range is claimed, “a skilled artisan must be able to reasonably discern a disclosure of that range,” id. at 8, and in this case, the court found that discrete examples falling within the claimed ranges did not provide sufficient written description support for those ranges.

The determination of whether a claimed range is supported by the specification is fact-specific, so this decision might not be controlling in all situations. In drafting a patent application, however, numerous variations of potential ranges should be explicitly stated, including variations that enclose all examples as well as variations that enclose discrete subsets of the examples in the specification. As in all cases of written description, the more examples the better. These steps are more crucial than ever because the Indivior decision requires greater support for ranges than prior Federal Circuit precedent.

The Claims

Anticipation depended on whether the claims at issue had written description support in the original application as filed. The patent generally describes orally-dissolvable films containing therapeutic agents. The claims recited limitations specifying the amount of a water-soluble polymeric matrix, including “about 40 wt % to about 60 wt %”, “about 48.2 wt % to about 58.6 wt %” and “about 48.2 wt %” of the matrix. These ranges were not expressly claimed or stated in the original application, and thus the question was whether a skilled artisan “could reasonably discern” a disclosure of each range from the specification. Id. at *8.

The Specification

The language of the specification was ambiguous—it noted different permissible percentages and stated that the amount of polymeric material could vary. Tables in the specification detailed examples that fell within the claimed ranges, but the percentages were not disclosed expressly and needed to be calculated from the data in the tables.

Lack of Written Description

The Federal Circuit stated that using these data points from examples in the specification to support the claimed ranges “amounts to cobbling together numbers after the fact.” Id. at *10. To satisfy the written description requirement, the specification must “state the invention,” not invite the reader “to go on a hunting expedition to patch together after the fact a synthetic definition of the invention.” Id. The disclosure of examples that fell within the claimed ranges provided insufficient written description support for the ranges, absent a more specific disclosure. Notably, the Federal Circuit did affirm the Board’s interpretation that the disclosure supported a claim limitation of “about 48.2 wt %”, even though the percentage was not explicitly set forth in the specification, because the limitation specified a particular amount, not a range.

The Dissent

One judge dissenting from the opinion, stating that “the majority cites no authority that written description support for a ‘closed range’ requires a disclosure of a closed range rather than discrete values.” Id. at *15. The dissent also noted that the opinion was contrary to prior decisions of the Federal Circuit permitting the use of discrete values to provide written description support for ranges. The dissent argues that written description was satisfied because the specification “explicitly identifies the essential desired characteristics possessed by the films of the claimed invention and identifies the polymer levels needed to impart those characteristics.” Id. Further, the aggregate weight percentage of the polymers in each embodiment in the examples was either 48.2% or 58.6% , a figure easily calculated by one of ordinary skill in the art. As such, the dissent would have found written description satisfied for the claimed ranges.