Addressing the issue of written description in a Hatch-Waxman litigation, the US Court of Appeals for the Federal Circuit affirmed the district court’s finding that the patent adequately described the claimed daily dose and no-loading dose negative limitation. Novartis Pharms. v. Accord Healthcare Inc., Case No. 21-1070 (Fed. Cir. Jan. 3, 2022) (Linn, O’Malley, JJ.) (Moore, CJ, dissenting).

Novartis’s Gilenya is a 0.5 mg daily dose of fingolimod hydrochloride medication used to treat relapsing remitting multiple sclerosis (RRMS). HEC filed an abbreviated new drug application (ANDA) seeking approval to market a generic version of Gilenya. Novartis sued, alleging that HEC’s ANDA infringed a patent directed to methods of treating RRMS with fingolimod or a fingolimod salt at a daily dosage of 0.5 mg without an immediately preceding loading dose.

The specification described the results of an Experimental Autoimmune Encephalomyelitis (EAE) experiment induced in Lewis rats showing that fingolimod hydrochloride inhibited disease relapse when administered daily at a dose of 0.3 mg/kg or administered orally at 0.3 mg/kg every second or third day or once a week, and a prophetic human clinical trial in which RRMS patients would receive 0.5, 1.25 or 2.5 mg of fingolimod hydrochloride per day for two to six months. The specification did not mention a loading dose associated with either the EAE experiment or the prophetic trial. It was undisputed that loading doses were well known in the prior art and used in some medications for the treatment of multiple sclerosis.

The district court found that HEC had not shown that the patent was invalid for insufficient written description for the claimed 0.5 mg daily dose or the no-loading dose negative limitation. The district court also found sufficient written description in the EAE experiment and/or prophetic trial and credited the testimony of two of Novartis’s expert witnesses. HEC appealed.

The Federal Circuit affirmed the district court’s decision. Turning first to the daily dose limitation, the majority held that the prophetic trial described daily dosages of 0.5, 1.25 or 2.5 mg and found no clear error by the district court in crediting expert testimony converting the lowest daily rat dose described in the EAE experiment to arrive at the claimed 0.5 mg daily human dose. Reciting Ariad, the Court explained that a “disclosure need not recite the claimed invention in haec verba” and further, that “[b]laze marks” are not necessary where the claimed species is expressly described in the specification, as the 0.5 mg daily dose was here.

Turning to the no-loading dose negative limitation, the majority disagreed with HEC’s arguments that there was no written description because the specification contained zero recitation of a loading dose or its potential benefits or disadvantages, and because the district court inconsistently found that a prior art abstract (Kappos 2006) did not anticipate the claims because it was silent as to loading doses. The Court explained that there is no “new and heightened standard for negative claim limitations.” The majority acknowledged that silence alone is insufficient disclosure but emphasized that [...]

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