Hospira, Inc. v. Fresenius Kabi USA, LLC

Case Name: Hospira, Inc. v. Fresenius Kabi USA, LLC, 946 F.3d 1322 (Fed. Cir. Jan. 9, 2020) (Circuit Judges Lourie, Dyk, and Moore presiding; Opinion by Lourie, J.) (Appeal from N.D. Ill., Pallmeyer, J.)

Drug Product and Patent(s)-in-Suit: Precedex® Premix (dexmedetomidine); U.S. Patent No. 8,648,106 (“the ’106 patent”)

Nature of the Case and Issue(s) Presented: Dexmedetomidine was a chemical compound that was effective as a sedative. In 1999, Abbott Laboratories (the predecessor-in-interest of Hospira) received FDA approval to market a 100 µg/mL dexmedetomidine hydrochloride formulation known as "Precedex Concentrate." The ‘106 patent addressed the problems associated with prior-art dexmedetomidine, and stated that “[t]he present invention is based in part on the discovery that dexmedetomidine prepared in a premixed formulation that does not require reconstitution or dilution prior to administration to a patient, remains stable and active after prolonged storage.” Hospira sought to enforce a claim to a pharmaceutical composition, which “when stored in a glass container for at least five months exhibits no more than about 2% decrease in the concentration of [the pharmaceutical].” The district court held the asserted patent claim invalid because it would have been obvious over the prior art, noting that the asserted claim limitations were inherent based on 20 tested samples from either Fresenius’ ANDA or Hospira’s NDA, and a person of ordinary skill in the art would have a reasonable expectation of success in achieving the “about 2% limitation.” On appeal, the Federal Circuit affirmed.

Why Defendants Prevailed: On appeal, Hospira argued that the evidence that the 2% limitation was inherent was derived from samples made according to the patent disclosure, which does not qualify as prior art. But this argument failed to acknowledge the fact that inherency arises when an inherent property existed in the prior art but was not appreciated. The samples as prepared were in the prior art, and only the inherent 2% limitation was not expressly disclosed in the prior-art reference. The Federal Circuit noted that “[e]xtrinsic evidence can be used to demonstrate what is ‘necessarily present’ in a prior art embodiment even if the extrinsic evidence is not itself prior art.” Thus, the lower court did not err in analyzing samples made following the prior art so long as they met the remaining elements of the asserted claim. As to the standard of inherency, the Federal Circuit held that there was no need for the lower court to reach any conclusion regarding a reasonable expectation of success, as “[i]f a property of a composition is in fact inherent, there is no question of a reasonable expectation of success in achieving it.”