IP Law Daily Applera did not infringe Enzo’s DNA sequencing patents under doctrine of equivalents
Thursday, August 3, 2017

Applera did not infringe Enzo’s DNA sequencing patents under doctrine of equivalents

By Mark Engstrom, J.D.

A federal district court correctly found that defendant Applera Corp. had not infringed, under the doctrine of equivalents, two claims of an Enzo Biochem patent on the use of nucleotide probes to detect or identify specific nucleic acid sequences in a sample of DNA or RNA, the U.S. Court of Appeals for the Federal Circuit has ruled. Because no reasonable jury could find, even under the doctrine of equivalents, that Applera’s "direct detection" products infringed Enzo’s patent on "indirect detection," the district court’s grant of summary judgment to Applera was affirmed (Enzo Biochem, Inc. v. Applera Corp., August 2, 2017, O’Malley, K.).

Prior history. In 2013, a jury awarded Enzo Biochem $48 million in reasonable royalty damages for Applera’s infringement of U.S. Patent No. 5,449,767, titled "Modified polynucleotides and methods of preparing same." Following the district court’s denial of post-trial motions filed by both sides, Applera appealed, and the Federal Circuit reversed the district court’s construction of the disputed claim terms because the errant construction covered the "direct" detection of a signaling moiety, in addition to indirect detection, but the appellate court found that the representative claim was limited to indirect detection. The case was remanded so the district court could determine whether the accused product infringed Enzo’s patent under the proper claim construction. The district court concluded that it did not, and summary judgment was granted to Applera. Enzo appealed, arguing that the district court had incorrectly interpreted the Federal Circuit’s prior decision ("Enzo II").

Scope of Enzo II. According to Enzo, the decision in Enzo II was limited to Claim 1 and did not change the previously construed scope of claims 67, 68, and 70, which covered both direct and indirect detection. The district court’s judgment on claims 67, 68, and 70 should thus be reversed, Enzo argued, and the jury’s infringement finding and damages award should be reinstated.

The Federal Circuit found that the district court had correctly interpreted Enzo II, which had consistently referred to the "claims" at issue and had thus extended to claims 8, 67, 68, and 70. Because Enzo did not argue that Applera had infringed claims 67, 68, and 70 under the Federal Circuit’s reading of the claims in Enzo II, the judgment of the district court was affirmed as to those three claims.

Doctrine of equivalents. Enzo conceded that Applera did not literally infringe claims 1 and 8 under the construction provided in Enzo II, but nevertheless argued that both claims were infringed under the doctrine of equivalents. According to Enzo, the district court had "misconstrued" the company’s expert declaration and had improperly drawn inferences in favor of Applera, rather than Enzo, in its summary judgment ruling.

The Federal Circuit disagreed. The district court had correctly granted summary judgment in favor of Applera and had sufficiently explained its ruling. The Enzo patent described its method of indirect detection as a superior means of detection, compared to direct detection, the district court noted, with ‘detection capacities equal to or greater than products which utilize’ direct detection." Accordingly, Enzo could not reasonably argue—and a jury could not find—that indirect detection and direct detection were "insubstantially different" methods of detection.

The appellate court noted that Enzo II had focused entirely on the conclusion that the asserted claims did not include direct detection, in part because they excluded direct detection. Enzo’s attempt to incorporate direct detection methods through the doctrine of equivalents thus failed. The concept of equivalency could not embrace direct detection, the court explained, because direct detection was specifically excluded from the scope of the claims.

The Federal Circuit thus concluded that no reasonable jury could find, even under the doctrine of equivalents, that Applera’s accused products, using direct detection, infringed Enzo’s "indirect detection" patent. The judgment of the district court was affirmed.

The case is No. 2016-1881.

Attorneys: L. Gene Spears (Baker Botts, LLP) for Enzo Biochem, Inc., and Enzo Life Sciences, Inc. Robert N. Hochman (Sidley Austin LLP) for Applera Corp.

Companies: Enzo Biochem Inc.; Enzo Life Sciences, Inc.; Applera Corp.

MainStory: TopStory Patent FedCirNews

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