Case Name: Astellas Pharma Inc. v. Sandoz Inc., Civ. No. 20-1589, 2023 WL 3934386 (D. Del. June 9, 2023) (Bataillon, J.) 

Drug Product and Patent(s)-in-Suit: Myrbetriq® (mirabegron); U.S. Patent No. 10,842,780 (“the ’780 patent”)

Nature of the Case and Issue(s) Presented: Astellas sued to enjoin a number of Defendants from marketing generic versions of Myrbetriq, an extended-release formulation of mirabegron for the treatment of overactive bladder. The ’780 patent claims overcoming “food effect,” described as a drug’s dangerous potency on an empty stomach contrasted by its inefficacy on a full one, by describing an extended-release formulation of mirabegron comprising a hydrogel-forming polymer, hydrophilic additive, and a dissolution limitation: that the dosage has dissolved no more than 39% at 1.5 hours and at least 75% after 7 hours. The parties engaged in a five-day bench trial. The court found that the asserted claims were invalid.

Why Defendants Prevailed: Defendants argued that the ’780 patent was invalid for not meeting the enablement requirement of 35 U.S.C. § 112. Specifically, Defendants argued that the patent specification did not offer sufficient clarity to enable a skilled artisan to make the invention without undue experimentation. Astellas countered that the specification directs routine activity by highly-skilled artisans in a predictable art. Taking Astellas at its word, the court found that Astellas conceded that the ’780 patent was enabled because it claimed invalid subject matter: a natural law applied via routine, conventional, and well-known methods. Relying extensively on Astellas’s expert conceding at trial that sustained release hydrogel formulations were well-known, well-characterized, not difficult to formulate, and not difficult to tune to arrive at a suitable dissolution profile, the court found that “Astellas’s zealous defense has conceded more fundamental ground. Embodying no more than the discovery of a natural law applied via well-known techniques for formulating sustained release tablets, the ’780 patent claims ineligible subject matter.”