Noven Pharm., Inc. v. Amneal Pharms. LLC

Minivelle®/estradiol transdermal system

September 2, 2020

GENERICally Speaking: A Hatch Waxman Litigation Bulletin

Case Name: Noven Pharm., Inc. v. Amneal Pharms. LLC, No. 18-cv-00699 (D. Del. Sept. 2, 2020) (Stark, J.) 

Drug Product and Patent(s)-in-Suit: Minivelle® (estradiol); U.S. Patents Nos. 9,833,419 (“the 419 patent”), 9,730,900 (“the 900 patent”), and 9,724,310 (“the 310 patent”)

Nature of the Case and Issue(s) Presented: Minivelle is an FDA-approved transdermal product for delivery of the hormone estradiol. It is indicated for the treatment of moderate to severe vasomotor symptoms due to menopause. Noven sued Amneal for patent infringement after Amneal had filed an ANDA with the FDA to market generic estradiol and certified against the patents-in-suit. The court held a six-day bench trial, finding: (i) Amneal’s ANDA product literally infringed the ’419 patent; (ii) Amneal’s ANDA product did not infringe the ’900 patent under the doctrine of equivalents (“DOE”); (iii) Amneal’s product did not infringe the ’310 patent under the DOE; (iv) the patents-in-suit were invalid for lack of enablement and written description; and (v) the patents-in-suit were not invalid under the on-sale bar.

Why Amneal Prevailed: On the issue of invalidity, the court found that the asserted claims were not enabled and lacked adequate written description. The court found that the asserted claims were broad and covered not just estradiol-patch systems, but also applied to any mucosal tissue, including oral, buccal, nasal, rectal, and vaginal tissue. Further, the specification failed to provide a working example of a transmucosal patch system. The court also found that the physiology and drug-release characteristics of oral, buccal, nasal, rectal, and vaginal mucosa could vary greatly. Additionally, the court explained that the state of the art of transmucosal patch designs did not provide meaningful guidance. Finally, concerning the quantity of experimentation, the court found that the amount of trial-and-error experimentation to make the full scope of the claims could have taken years. Regarding the lack of written description, the court explained that the specification lacked any description or example of a transmucosal estradiol system, including any description or example of an oral, buccal, rectal, or vaginal patch system. The specification used the words “flux” and “transdermal,” but the words “oral,” “buccal,” “nasal,” “rectal,” or “vaginal” mucosa were never recited in the specification.

Amneal also argued that the patents-in-suit were anticipated by Noven’s offer for sale and sale of its Vivelle-Dot® products. The court explained that the Vivelle-Dot® products were offered for sale under a supply agreement with Novartis. But Amneal was unable to prove that the Vivelle-Dot® products offered for sale actually met the coat weight, flux, and estradiol-content limitations of the patents-in-suit.

On the issue of infringement, the court found that Amneal infringed the ’419 patent. The asserted claims of the ’419 patent recite a “coat weight of greater than 10 mg/cm2. Amneal’s ANDA product was permitted, by the terms of its ANDA, to have an upper limit coat weight of 10.75 mg/cm2 for any individual measurement and 10.5 mg/cm2 for the average coat-weight value. In finding literal infringement, the court rejected Amneal’s argument that the claim term actually referred to a “target weight” and not the actual coat weight. Next, the court found that Amneal did not infringe the ’900 and 310 patents. Noven did not allege direct infringement of these patents. The court found that the doctrine of prosecution-history estoppel precluded a finding of DOE infringement of these patents that recited a coat weight “greater than about 10 mg/cm2.” The court construed the limitation to mean “having a coat weight which weighs more than 110% of 10 mg/cm2.” As originally filed, the claims included no coat weight, and Noven added this limitation to overcome an Examiner rejection. Further, the Examiner expressly cited coat weight as a reason for allowing the claims. Thus, under Festo, the court concluded that Noven surrendered all coat weights that were not greater than 11 mg/cm2. That is, Noven could not claim infringement by equivalents of an embodiment with a coat weight of less than 11 mg/cm2. Because the coat weight of Amneal’s ANDA product was to be no greater than 10.75 mg/cm2, it could not infringe under the DOE.

Oren D. Langer


Managing Partner, New York Office
Member of Executive Board

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