January 4, 2022

Silence is not only Golden, it is a Written Description if the Skilled Artisan Would Understand it that Way

In Novaritis Pharmaceuticals Corp. v. Accord Healthcare, Inc., [2021-1070] (January 3, 2021) the Federal Circuit affirmed the district court’s determination that U.S. Patent No. 9,187,405 on a treatment for relapsing remitting multiple sclerosis (“RRMS”) is not invalid and that HEC’s Abbreviated New Drug Application infringes.

The ’405 patent claimed a daily dosage of fingolimod “absent an immediately preceding loading dose,” which HEC challenged as lacking written description. The district court found sufficient written description in the EAE model and the Prophetic Trial, neither of which recited a loading dose.

On appeal, HEC attacked the expert testimony underlying the district court’s determination that the EAE experiment describes a 0.5 mg daily human dose as “undisclosed mathematical sleights of hand.” The Federal Circuit disagreed, noting a disclosure need not recite the claimed invention in haec verba. The disclosure need only clearly allow persons of ordinary skill in the art to recognize that the inventor invented what is claimed.

The Federal Circuit said that to accept HEC’s argument would require it to ignore the perspective of the person of ordinary skill in the art and require literal description of every limitation, in violation of precedent. The Federal Circuit found no clear error in the district court’s reliance on expert testimony in finding description of the 0.5 mg daily human dose in the EAE experiment results.

The Federal Circuit also rejected HEC’s challenge to the negative limitation “absent an immediately preceding loading dose.” The Federal Circuit began by noting that it was well established that there is no “new and heightened standard for negative claim limitations.” Inphi Corp. v. Netlist, Inc., 805 F.3d 1350, 1356 (Fed. Cir. 2015).

The Court said that negative claim limitations are adequately supported when the specification describes a reason to exclude the relevant limitation. Adding that a specification that describes a reason to exclude the relevant negative limitation is but one way in which the written description requirement may be met. The Federal Circuit said that the written description requirement is satisfied where the essence of the original disclosure conveys the necessary information — regardless of how it conveys such information and regardless of whether the disclosure’s words are open to different interpretations.

The Federal Circuit pointed to expert testimony that one of ordinary skill in the art would understand the examples to exclude a loading does, so the specification’s apparent silence provided adequate written description of the negative limitation. The Court concluded that written description in this case, as in all cases, is a factual issue.

In deciding that the district court did not clearly err in finding written description for the negative limitation in the ’405 patent, the court said that it was not establishing a new legal standard that silence is disclosure. The Federal Circuit said that it was merely holding that on the record before it, the district court did not clearly err in finding that a skilled artisan would read the ’405 patent’s disclosure to describe the “absent an immediately preceding loading dose” negative limitation.