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Aventis Pharma S.A. v. Amphastar Pharmaceuticals, Inc.

Citation. Aventis Pharma S.A. v. Amphastar Pharms., Inc., 525 F.3d 1334, 87 U.S.P.Q.2D (BNA) 1110 (Fed. Cir. May 14, 2008)
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Brief Fact Summary.

Aventis (Plaintiff) held a patent on a drug that it claimed had a significant improvement in half-life over a drug covered by a European patent that was nearly identical.  Plaintiff failed to disclose that its half-life data came from using different doses to compare the drug.  When using the same dose to compare, results showed barely a difference in half-life.  The district court held Plaintiff had intent to deceive when it did not disclose the relevant information of the dose comparisons of half-life.  Therefore, because of inequitable conduct, the issued patent was unenforceable.

Synopsis of Rule of Law.

Data relevant to patentability must be disclosed with the specifications, or when clear and convincing evidence of intent to deceive is shown regarding the relevant data, the patent will not be enforceable.


Plaintiff held the ‘618 patent, which was surrendered when Plaintiff received the ‘743 patent.  Both patents related to a composition made up of low molecular weight heparins.  The drugs, marketed as Lovenox in the United States and Clexane in Europe, work to prevent blood clotting and to minimize the chance of hemorrhaging, especially during high-risk surgery.  The advantage claimed by the patented drugs is that they exhibit a longer half-life compared to heparin.  At first, the patent claims were rejected based on obviousness and anticipation because the prior art, especially European Patent ‘144, taught a product that was almost identical.  Plaintiff disputed the rejections arguing that the half-life of the new drugs was significantly longer, which demonstrate a difference in structure.  Plaintiff continued to rely on the difference in half-life in the appeals that followed until the patent was allowed.  Plaintiff later sued Amphastar Pharmaceuticals, Inc. (Defendant) for patent infringement claiming they made and marketed the drug in generic versions.  The district court considered Defendant’s argument that the patent was invalid, and held the half-life improvement to be relevant to patentability because that was the reason the patent was finally issued by the examiner.  The district court found Plaintiff had intent to deceive the examiner because Plaintiff provided no credible explanation for its reliance on an allegedly improved half-life when it had compared half-life at different doses without disclosing this dosage information.  When compared at the same doses, the half-life was about the same.  The district court granted summary judgment to Defendant and declared the patent was not enforceable due to inequitable conduct, which was intent to deceive.  Plaintiff appealed to this court claiming the dose information was not relevant to the patentability because otherwise the examiner would have requested it when half-life data was presented to her.  Plaintiff also claimed its expert, Dr. Andre Uzan, informed the examiner of the difference in dose when his declaration stated “it enables the same effect to be achieved with lower dosages.”  This court held Dr. Uzan’s statement did not completely inform the examiner and the absence of dose information was a failure to disclose relevant information.  The dose information was relevant to the issue of patentability.  However, this court remanded for the district court to determine intent to deceive if the different dose comparison was reasonable within the field and therefore failure to disclose was unintentional.  On remand, regarding the limited issue of intent to deceive, the district court held a bench trial and again found Plaintiff had intent to deceive the examiner.  Plaintiff appealed again.


Must data relevant to patentability be disclosed with the specifications, or when clear and convincing evidence of intent to deceive is shown regarding the material data, will the patent be enforceable?


(Prost, J.)  Yes.  Data relevant to patentability must be disclosed with the specifications, or when clear and convincing evidence of intent to deceive is shown regarding the material data, the patent will not be enforceable.  Inequitable conduct’s element of intent to deceive is satisfied by all the evidence, including evidence of good faith, showing sufficient responsibility requiring a finding of intent to deceive.  A review of the related facts and circumstances often points to this intent.  On this second appeal, Plaintiff argues Dr. Uzan compared the half-life at different doses to show a difference in property to address the obviousness rejection instead of addressing the anticipation rejection by showing a difference in composition.  To demonstrate a difference in property, the dose comparison can differ because it is more appropriate to use the clinically relevant dose of each compound.  Therefore, Plaintiff argues it was a mistake for the district court to consider differences in composition to be central to patentability and a further mistake to find that the comparisons of Dr. Uzan were intended to show differences in composition.  However, there is no indication the district court considered only the anticipation rejection when the court was clearly aware of the additional obviousness rejection and considered the half-life comparisons for both rejections.  The court may have been wrong to believe anticipation remained as a rejection when the examiner ultimately withdrew that basis for rejection, but the mistake was not critical since the court already found intent to deceive based on the specification example and the earlier declarations of Dr. Uzan which contained misleading dose information.  Dr. Uzan’s failure to disclose the dose information in the example was not unintentional and was not excused by his intent to disclose the information even though he failed to do so.  Affirmed.


(Rader, J.)  Usually a finding of inequitable conduct applies to only the most appalling cases, and in this case the evidence does not meet the level of clear and convincing evidence regarding intent to deceive.  Inequitable conduct claims are used as litigation tactics that have caused a merging of intent to deceive with materiality of undisclosed information instead of focusing on the two issues separately.  The dose information should have been disclosed by Dr. Uzan since it was material to patentability, but the record hardly indicates intent to deceive.  It was Dr. Uzan himself who revealed the mistake and the half-life data were apparently not relevant for patentability since the patent issued later without the offending example.  The finding of inequitable conduct should be reversed.


The majority inferred the intent to deceive element because Dr. Uzan failed to disclose the material comparison data instead of requiring a clear finding that Dr. Uzan intended to deceive the patent office.  The dissent wished to go back to a clearer delineation between the materiality of the data withheld and the actual demonstration of intent to deceive because using inequitable conduct as a defense is increasing.  Congress responded in part to the concerns addressed in the dissent with the Patent Reform Act of 2007 which would make the defense of inequitable conduct more difficult to be used as a litigation tactic.

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