Addressing the issue of negative claim limitations, the US Court of Appeals for the Federal Circuit granted a petition for panel rehearing, vacated its prior decision (authored by now-retired Judge O’Malley) and reversed the district court’s finding that the patent was not invalid for inadequate written description. Novartis Pharms. v. Accord Healthcare Inc., Case No. 21-1070 (Fed. Cir. June 21, 2022) (Moore, C.J.; Hughes, J.) (Linn, J., dissenting).

This is the second time this Hatch-Waxman case has been before the Federal Circuit. Novartis sued HEC, alleging that HEC’s abbreviated new drug application infringed a patent directed to methods of treating remitting multiple sclerosis (RRMS) with fingolimod or a fingolimod salt at a daily dose of 0.5 mg without an immediately preceding loading dose. The district court found sufficient written description for the claimed 0.5 mg daily dose and no-loading dose negative limitation. In January 2022, the Federal Circuit affirmed the district court’s decision finding adequate written description.

HEC petitioned for panel rehearing. The Federal Circuit granted the petition, vacated its January 2022 decision and reversed the district court’s judgment finding adequate written description for the no-loading dose negative limitation. The majority explained that “silence is generally not disclosure” because “[i]f it were, then every later-added negative limitation would be supported so long as the patent makes no mention of it.” The majority also explained that implicit disclosure cannot satisfy the written description requirement if it would render the limitation obvious to a skilled artisan. The majority emphasized that while a negative limitation need not be recited in the specification in haec verba, there generally must be something in the specification that conveys to a skilled artisan that the inventor intended the exclusion—for example, a description of a reason to exclude the relevant element. Here, the majority found that the specification made no mention of the presence or absence of a loading dose. This silence cannot support a later-added claim limitation that precludes loading doses, particularly where there was no evidence that the patentee precluded the use of a loading dose and skilled artisans agreed that loading doses are sometimes given to RRMS patients.

Judge Linn (a member of the majority in the January 2022 opinion) dissented, arguing that the majority applied a heightened written description standard requiring not only a “reason to exclude” but a showing that the negative limitation was also “necessarily excluded.” He stated that the question was not whether the patentee precluded the use of a loading dose, but whether the claim limitation that precluded a loading dose was supported by the specification’s written description that disclosed only a daily dose. Judge Linn argued that disclosure along with the testimony of Novartis’s experts implied an absence of a loading dose to a skilled artisan, and that is all that is required for adequate written description. Citing precedent and the US Patent & Trademark Office’s guidance in the Manual of Patent Examining Procedure, he argued that newly added claims or claim limitations may be supported in the specification through express, implicit or inherent disclosure. “What is critical is how a skilled artisan would read the disclosure—not the exact words used.”