United States: Federal Circuit Rejects District Court’s Construction Of "At Least One Of" As "One or More"

In Enzo Biochem Inc. v. Applera Corp., No. 14-1321 (Fed. Cir. Mar. 16, 2015), the Federal Circuit reversed the district court's claim construction, vacated the jury's finding of infringement, and remanded for further proceedings under the Court's articulated claim construction.

Enzo Biochem Inc., Enzo Life Sciences, Inc., and Yale University (collectively "Enzo") asserted claims of U.S. Patent No. 5,449,767 ("the '767 patent") against Applera Corp. and Tropix, Inc. (collectively "Applera").  The claims are generally directed to nucleotide probes used in nucleic acid labeling and detection.  The detectable signal may be generated either from a label itself ("direct detection") or from a secondary chemical agent that is bound to the label ("indirect detection").  The district court construed the phrase "A comprises at least three carbon atoms and represents at least one component of a signalling moiety capable of producing a detectable signal" as "A comprises at least three carbon atoms and is one or more parts of a signalling moiety, which includes, in some instances, the whole signalling moiety."  Slip op. at 7 (emphases added) (quoting Enzo Biochem, Inc. v. Applera Corp., No. 3:04-CV-929, 2006 WL 2927500, at *2, *4 (D. Conn. Oct. 12, 2006)).  The district court further construed the claim term "signalling moiety" as "a chemical entity capable of producing a detectable signal."  Id. (quoting Enzo Biochem, 2006 WL 2927500, at *2, *4).  The district court's construction allowed for both direct and indirect detection of the claimed compound.  Based on this construction, a jury found that the asserted claims were infringed and that the '767 patent was not invalid for lack of written description and enablement.  Applera appealed.

"[T]he phrase 'at least one component of a signalling moiety' indicates that the signalling moiety is composed of multiple parts as the term 'component' in and of itself indicates a multipart system."  Slip op. at 9.

On appeal, the Federal Circuit rejected the district court's claim construction, holding that the claims should have been construed to cover only indirect detection.  The Court found that the language of the claims supported such a construction.  Specifically, the Court held that the phrase "at least one component of a signalling moiety" suggests that the moiety is composed of multiple parts because the "term 'component' in and of itself indicates a multipart system."  Id. at 9.  The Court concluded that it would therefore be improper to construe the phrase to allow for a single-component system because such a construction "would read out the phrase 'component of a signalling moiety.'"  Id. at 9-10.  Further, the Court reasoned that since the claim language requires that "A" be attached through a linkage group that "does not substantially interfere with formation of the signalling moiety," then "'A' cannot be the whole signalling moiety, as the claimed compound does not include a formed signalling moiety."  Id. at 10 (citation omitted).

The Federal Circuit rejected the argument that the term "at least one of" allows for both direct and indirect detection under Howmedica Osteonics Corp. v. Wright Medical Technology, Inc., 540 F.3d 1337 (Fed. Cir. 2008), in which "at least one" was construed to mean "one or more."  Slip op. at 10-11 (quoting Howmedica, 540 F.3d at 1344).  Specifically, the Court held that Howmedica was inapposite because, "unlike in Howmedica where the claim did not require the prosthetic knee to have more than one condylar element, here the plain reading of the disputed claim term requires that a signalling moiety be composed of components, of which at least one is 'A.'"  Id. at 11.

The Federal Circuit also found support for its claim construction in the specification.  First, the Court found that the specification "never [describes] that 'A' alone can be a signalling moiety."  Id.  Second, the Court relied on the specification's background section, which "describes how 'A,' a biotin, iminobiotin, or lipoic acid, forms a detectable unit, i.e., a signalling moiety, upon interaction with avidin or antibodies."  Id.  at 11-12.  Third, the Court stated that the only discussion of direct detection was in the context of explaining that indirect detection is superior.  The Court also noted that the portions of the specification pointed to by Enzo during oral argument, considered alone or in combination with Enzo's expert's testimony, also did not support a disclosure of direct detection.

Based on the language of the claims and the specification, the Court concluded that the district court erred in construing the asserted claims to cover both direct and indirect detection.  Accordingly, the Court reversed the district court's claim construction, vacated the jury's finding of infringement, and remanded the case for further proceedings consistent with the Court's claim construction.

Judge Newman dissented.  In her opinion, Judge Newman reasoned that "[t]he rules of grammar and linguistics, even in legal documents, do not establish that 'at least one' means two or more."  Newman Dissent at 4.  Further, Judge Newman noted that the district court construed "at least one" not just based on grammar and linguistics, but also based on the intrinsic record and extrinsic evidence.  Judge Newman believed that in view of the recent Supreme Court decision in Teva Pharmaceuticals USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831 (2015), "appropriate deference must be given to the findings of the district court."  Slip op. at 5.  Since there was no illustrated error of fact or law in her opinion, Judge Newman opined that there were no grounds for reversing the district court's claim construction.

Judges: Prost (author), Newman (dissenting), Linn

[Appealed from D. Conn., Judge Arterton]

This article previously appeared in Last Month at the Federal Circuit, April, 2015

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

Copyright © 2015 Finnegan, Henderson, Farabow, Garrett & Dunner, LLP | All rights reserved

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