Hospira v. Fresenius (Fed. Cir. 2020)
Hospira lost at the district court on obviousness — with the court finding its asserted Claim 6 of US8648106 invalid as obvious. On appeal, the Federal Circuit affirmed and now Hospira has petitioned for en banc rehearing — focusing in on the role of inherency in combining prior art.
The claim is directed to the sedative dexmedetomidine in a “ready use liquid pharmaceutical composition” in a glass container and a shelf-life of 5-months with “no more than about 2% decrease” in the concentration of the active drug.
The “no more than about 2%” loss claim appears functionally described result — if you build the vial and fill it in the way described by the inventor then you’ll presumably get the shelf life.
Here, all of the limitations found in the claim are found within the prior art and the district court held that it would have been obvious for PHOSITA to combine the references as such. The one lacking element was the <2% loss limitation — that one was not expressed in the prior art. However, the district court concluded that the functional limitation is an inherent result of the combination — and thus the whole claim is obvious.
Whether a party seeking to show that a property is inherent in a combination of prior art disclosures must affirmatively prove that the property is necessarily present in that combination, regardless of how that combination is prepared.
Hospira’s basic arguments here are (1) that inherency for obviousness must be proven with clear and convincing evidence and (2) that inherency for obviousness only ‘counts’ if necessarily present in the proposed combination, not merely likely or possibly present.
In their 2005 paper on Inherency, Professors Dan Burk and Mark Lemely took the position that inherency should have almost no role in the obviousness analysis because of its hindsight approach.
Hindsight reconstruction of the invention, looking back at the prior art to second-guess the inventor once the invention is available, is anathema to an obviousness assessment. But inherency is all about hindsight—a recognition today that an invention was present in the prior art, even though it was not understood to be there at the time.
Given the hindsight limitations on obviousness, we expect the role of inherency under § 103 to be extremely limited, if not altogether nonexistent.
Dan Burk, Mark Lemley, Inherency, 47 William & Mary Law Review 371 (2005).