A weekly summary of the precedential patent-related opinions issued by the Court of Appeals for the Federal Circuit and the opinions designated precedential or informative by the Patent Trial and Appeal Board.


Indivior UK Limited v. Dr. Reddy's Laboratories S.A., et al., Nos. 2020-2073, -2142 (Fed. Cir. (PTAB) Nov. 24, 2021). Opinion by Lourie, joined by Dyk. Opinion concurring in part and dissenting in part by Linn.

Dr. Reddy's initiated an IPR challenging claims 1-5 and 7-14 of a patent owned by Indivior relating to orally dissolvable films containing therapeutic agents. Claim 8 requires a specific polymer weight percentage, and the other claims require a range of polymer weight percentages. Dr. Reddy's argued that the polymer weight percentage limitations lacked written description support in a parent application and thus were not entitled to the benefit of the parent application's filing date. Indivior disagreed and argued that the parent application sufficiently supported the claims, but conceded anticipation of the claims if they are not given the parent application's filing date.

The Patent Trial and Appeal Board held that claims 1-5, 7, and 9-14 lacked written description support for the claimed ranges and thus were anticipated, but that claim 8 had sufficient support and thus was not anticipated. Both parties appealed. 

The Federal Circuit affirmed. Addressing the claims reciting a range of polymer weight percentages, the court held that a skilled artisan would not be able "to reasonably discern a disclosure of that range" in the parent application. The court held that the specification was not sufficiently clear: "Here, one must select several components, add up the individual values, determine the aggregate percentages, and then couple those aggregate percentages with other examples ... to create an otherwise unstated range. That is not written description of the claimed range."

Addressing claim 8, the Federal Circuit reached the opposite conclusion. Claim 8 did not require a range, instead reciting "about 48.2 wt %" as the amount of polymer. The court explained that "even though ... the number '48.2 wt %' is not explicitly set forth" in the parent application, the court deferred to the Board's fact-finding, accepting "that there is substantial evidence to support the Board's decision concerning claim 8."

Judge Linn dissented in part. In his view, the parent application provided written description support for all of the challenged claims, including those reciting a range of polymer weight percentages. Judge Linn stated that the majority's decision "rests on an improper reading" of the parent application, "applies an overly demanding standard for written description for ranges," and "fails to follow our precedent."

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