MSD antibiotic patent obvious, says Federal Circuit
Merck Sharp & Dohme (MSD) has suffered a loss at the US Court of Appeals for the Federal Circuit, after the court affirmed an earlier finding of obviousness.
Yesterday, October 26, in a split ruling, the court found US patent number 6,486,150 invalid under 35 USC section 103.
The patent, owned by MSD, is directed to a process for preparing a stable formulation of ertapenem, an antibiotic compound.
MSD uses ertapenem in its drug Invanz, which treats severe infections of the skin, lungs, stomach, pelvis, and urinary tract.
In May 2014, Hospira notified MSD that it had filed an Abbreviated New Drug Application to manufacture a generic version of Invanz, the principal component of which is the carbon dioxide adduct of ertapenem.
Merck responded by suing Hospira for infringement of the ‘150 patent and US number 5,952,323 at the US District Court for the District of Delaware.
The Delaware court concluded that the asserted claims of the ‘323 patent were valid and infringed.
It also found that the asserted claims of the ‘150 patent would be infringed, but were invalid as obvious over the ‘323 patent and PCT publication WO 98/18800 (Almarsson).
“The district court found that, while none of the three steps of claim 21 of the ‘150 patent was individually taught by the prior art, the ‘recipe’ for the final formulation was disclosed and the three steps leading to that formulation were nothing more than conventional manufacturing steps that would have been obvious from the disclosures and thus were the product of routine experimentation,” said the Federal Circuit.
The court reviewed Merck’s objective evidence, finding that commercial success and copying by others were shown, but that the objective evidence could not overcome the “strong prima facie case of obviousness” established by Hospira.
Merck appealed to the Federal Circuit, arguing that it was “undisputed that none of the claimed steps is disclosed in the prior art”.
“Merck contends that the court erred in relying solely on the ‘knowledge, creativity, and common sense’ of a skilled artisan because ‘common sense’ is properly invoked to provide a motivation to combine, not to supply a missing claim limitation,” explained Circuit Judge Alan Lourie, on behalf of the court.
In an 18-page decision, the Federal Circuit affirmed the lower court’s finding.
“Thus, it was reasonable for the district court to deduce from the evidence that the order and detail of the steps, if not already known, would have been discovered by routine experimentation while implementing known principles. The court’s analysis thus involved no legal error,” added Lourie.
MSD also claimed that the district court “improperly discounted” its objective evidence, but the Federal Circuit found that the lower court didn’t “err in finding the invention to have been obvious at the time the invention was made”.
Circuit Judge Pauline Newman filed a dissenting opinion, claiming that “it is time to remedy our inconsistent treatment of the procedures and burdens in applying the evidentiary factors of obviousness, despite the clarifying precedent in Graham v John Deere Co”.
According to Newman, Graham “resolved prior inconsistencies and established what was seen as a wiser standard of obviousness”.
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