Missing IR Spectroscopy Peak Defeats Infringement

Earlier this month, Judge Cecchi of the District of New Jersey held that a claim directed to a composition exhibiting several IR spectroscopy peaks is not infringed when an accused ANDA product does not produce one of the claimed peaks.  Sebela International Limited v. Actavis Laboratories FL, Inc.  The court also found two method patents invalid as obvious where the claimed dose was encompassed by a range of doses disclosed in the prior art.

Plaintiff, Sebela International Limited (“Sebela”) sued several generic drug manufacturers for infringement of two patent groups.  The first patent was directed to a paroxetine mesylate composition, while another group of patents were directed to methods of treating thermoregulatory dysfunction with paroxetine.  The court held that defendants did not infringe the former, and that the latter were invalid as obvious, lacking utility, and lacking adequate written description.

Infringement of the Composition Patent

The infringement determination hinged on whether defendants’ crystalline paroxetine mesylate products produce IR spectra with peaks corresponding to the claimed peaks.  Defendants’ ANDA products did not exhibit one of the claimed peaks, even when a broad error range was applied.  Plaintiff argued that a spectroscopy claim can still be infringed despite missing a claimed peak because a POSA would compare the peaks in the patent to the full spectrum produced by the accused product to determine whether the spectrum corresponds to the claims, and could do so even if some peaks were missing.  Plaintiff further argued that Federal Circuit precedent holding that presence of a single peak was not sufficient to find infringement implied that the absence of a single peak was not sufficient to defeat infringement.  The court rejected Plaintiff’s argument, stating “[i]n any patent case, the presence of a single limitation is not sufficient to establish a claim for infringement, but the absence of a single limitation is sufficient to defeat a claim for infringement.”  The court confirmed that each peak constitutes an independent limitation and reaffirmed the fundamental principle that all limitations are material and must be present to support infringement.

Invalidity of the Method Patents

The parties’ fight over the obviousness of the method patents focused on whether the prior art adequately disclosed use of the claimed dose to treat vasomotor symptoms. The claims required a dose of 7.5 mg/day.  The prior art disclosed doses in the range of 0.09 mg/day to 12 mg/day, with 0.21 mg/day to 8.4 mg/day identified as the most preferable range. Plaintiff argued that a POSA would find this range incredible, but the court held that Plaintiff failed to rebut the presumption that prior art is enabled.  The court further found that the claimed 7.5 mg/day dose was not critical, as the specifications disclosed efficacy at doses from 0.1 mg/day to 10 mg/day, and the patents did not otherwise identify 7.5 mg/day as significant.