Sciele Pharm. Inc. v. Lupin Ltd.

The burden for proving invalidity is clear and convincing evidence; it is not heightened if prior art references were before the Patent Office nor is it lowered if a patent issues erroneously.

October 16, 2012

GENERICally Speaking

Case Name:  Sciele Pharm. Inc. v. Lupin Ltd., Case No. 2012-1228, 684 F.3d 1253 (Fed. Cir. July 2, 2012) (Circuit Judges Lourie, Prost, and Moore presiding; Opinion by Moore) (Appeal from D. Del., Kugler, J.)

Drug Product and Patent(s)-in-Suit:  Fortamet® (metafomin hydrochloride extended-release tablets); U.S. Patent No. 6,866,866 (“the ’866 patent”)

Nature of the Case and Issue(s) Presented:  The ’866 patent claims dosage forms with a “mean time to maximum plasma concentration (Tmax) of the drug which occurs at 5.5 to 7.5 hours after oral administration on a once-a-day basis to human patients.”  During prosecution, the applicant discussed the importance of Tmax and the examiner indicated that the closest prior art, the Cheng reference, suggests the general teaching of a Tmax of eight hours.  In response, the applicant cancelled a number of claims which had an upper Tmax range of 7.5 hours, and re-wrote a then-pending claim, which had an upper Tmax range of seven hours, into independent form.  Despite cancelling the rejected claims, the applicant received a notice of allowance.  The applicant contacted the Patent Office and explained that the notice of allowance mistakenly allowed cancelled claims.  Even though the Examiner issued a supplemental notice acknowledging the amendment, removing the cancelled claims, and allowing the amended claims, as issued, the ’866 patent contained the cancelled claims from the first notice of allowance—not the supplemental notice of allowance.  Subsequently, plaintiffs asserted the claims of the ’866 patent against Lupin, including the claim that referenced a Tmax of 7.5 hours.

On December 6, 2011, the district court granted a preliminary injunction, which the Federal Circuit subsequently vacated and remanded because the district court failed to address Lupin’s obviousness arguments.  On remand, the district court reinstated the preliminary injunction based on two principle findings: (i) that it was required to defer to the Patent Office, notwithstanding the odd sequence of events that gave rise to the issuance of the ’866 patent; and (ii) that KSR was not directly applicable to the current case because the prior art was before the PTO when the ’866 patent issued.  The Federal Circuit held that the district court misinterpreted the law, and, once again, vacated the preliminary injunction and remanded.

Why Lupin Prevailed: Lupin argued that the presumption of validity should not attach because of the erroneous issuance of the cancelled claims.  Plaintiffs argued that there should be a heightened presumption of validity because the prior art references that Lupin relied on were before the Patent Office during prosecution.  The Federal Circuit found that both parties were wrong.  First, deference to the Patent Office is reflected in the “clear and convincing” evidence burden for proving invalidity.  “[W]hether a reference was before the PTO goes to the weight of the evidence…[b]ut the presumption of validity and accompanying burden of proof, clear and convincing evidence, are not altered.”  Second, the presumption of validity applies to all issued patents, and rejecting the issued claims of the ’866 patent because of “quirks in the prosecution history” is inconsistent with that presumption.  But that does not mean that courts should ignore the prosecution history.  Other than recognizing that the prosecution history was “puzzling,” the Federal Circuit found that the district court did just that, ignored the prosecution history.  The Court then went on to find a substantial question of validity of the claims of the ’866 patent in view of the Cheng reference, among others.  The Federal Circuit further held that the district court clearly erred in its conclusion that there was no motivation to combine Cheng with other prior art references.  For these reasons, the Court vacated the preliminary injunction and remanded the case back to the district court.

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