Aventis Pharma S.A. v. Amphastar Pharmaceuticals, Inc.
525 F.3d 1334 (Fed. Cir. 2008)
Aventis invented a drug to
stop blood clots. They filed for a patent on the drug. It was initially
The USPTO found that the
drug was obvious when compared to
some prior art. If Aventis
wanted a patent, they would have to show how their drug had different
properties than what was already available in the prior art.
Aventis came back and amended
their patent. This time it was approved.
Avantis amended their patent
to show evidence that their drug stayed in the body for less time (aka
had a shorter half-life) than the drugs described in the prior art. That made it different.
In the biochemical
community, it is often difficult to tell exactly what a compound is, so
patents are granted more on what the properties of the compound is, not
what the exact compound is.
Amphastar was marketing their
own, similar blood clotting drug. They sued Aventis to have the Aventis
Amphastar argued that when
Aventis did their half-life tests, they used a different dosage for their
drug than for the drugs in the prior art. That's why the half-lives appeared to be different. Amphastar
argued that this was deceitful and so Aventis' patent should be
invalidated due to inequitable conduct.
The Trial Court invalidated
the patent. Aventis appealed.
The Trial Court found that
Aventis was guilty of inequitable conduct.
The Court found that there
was evidence of an intent to deceive
because there was no scientifically defensible reason why Aventis should
have used different dosages, and no legitimate reason for their failure
to disclose that fact to the USPTO.
Note that if you are found
guilty of inequitable conduct on
even a single small point then the entire patent is declared invalid. You can't amend,
or just throw out the single claim.
See 35 U.S.C. §251.
The Appellate Court affirmed.
The Appellate Court found
that there are two elements to inequitable conduct - an intent to deceive, and the materiality of the deception.
The Court found that the
more material the omission or
misrepresentation, the less intent must be shown to elicit a finding of inequitable
The Court looked at the
evidence, and found that there was a lot of evidence of an intent to
deceive on an issue that was very material to whether the patent was granted or not.
Aventis argued that they
used different dosages because when the drugs would be used clinically,
they would use different doses.
Of course even if that is
true, Aventis should have been clear about it in their patent
In a dissent it was argued
that inequitable conduct should be
restricted to only the most extreme cases of fraud and deception.