Issue 15 | April 12, 2002
CAFC Fortifies Written Description
Requirement in Biotech Cases
 Enzo Biochem, Inc. v. Gen-Probe Inc. et al., (Case No. 01-1230, Fed. Cir., April 2, 2002). The Federal Circuit affirms summary judgment that describing and claiming a nucleic acid molecule according to a functional property, coupled with reference to a specimen of the molecule in a public depository, does not satisfy the written description requirement of 35 U.S.C. §112, 1. The statute requires an identifying description of what the invention "is", not merely what it "does". This description can not be incorporated by reference to a sample of the invention in a public depository, nor by inviting the public to consult extrinsic evidence or do further work, as by analyzing a deposited sample. Though a public deposit may show that the inventors had actual "possession" of the invention, "possession" is not itself a "description" of the invention in the patent specification.

U.S. Patent No. 4,900,659 to Enzo Biochem claimed nucleic acid molecules that bind or "hybridize" at least 5 times more selectively to N. gonorrhoeae, the bacteria that causes gonorrhea, than to a different but related organism, N. meningitidis. The ability of these molecules or "probes" to hybridize preferentially could be exploited to provide a more sensitive diagnostic test for gonorrhea, by ruling out "false positives" from N. meningitidis. The '659 specification gave a description of procedures used to isolate exemplary probes, and of a protocol used to test for preferential hybridization. The specification did not provide sequence information, nor any other uniquely identifying structural description of the probes. Three probes actually developed by Enzo hybridized 50 times more readily with N. gonorrhoeae than N. meningitidis. Specimens of these probes were deposited with the American Type Culture Collection (ATCC), a public depository, and the deposits were identified in the specification.

Writing for the majority, Judge Lourie affirmed the district court ruling that the composition was described and claimed only according to its function, to selectively hybridize with N. gonorrhoeae, and that this failed to satisfy the written description requirement of §112, 1. An ATCC deposit of exemplary specimens, even if showing "possession" of the invention, did not amount to an inherent written description, and related instead to the enablement requirement of §112, 1.

More broadly, the decision holds that the ability of one molecule (a probe) to bind another molecule (a target), without more, describes a function only; it does not describe the molecule or probe itself. "Hybridization distinguishes the claimed nucleotide sequences from unclaimed sequences only by what they do, which is a purely functional distinction." Hybridization was not a sufficiently detailed and relevant identifying characteristic, because it was not coupled with a known or disclosed correlation between function and structure. "Thus, in the absence of sequence information for its hybridization site, a nucleic acid described only by its ability to hybridize with another DNA fails to meet the requirements of §112, 1." Although Enzo had three probes that hybridize as claimed, the broad claims are directed, in circular fashion, to all sequences that so hybridize. "Enzo claimed anything that works, without defining what works."

The "fatal flaw" in all the claims was defining the invention "by biological activity and function" and not according to structure. This was not cured by supporting language in the specification, because even if a claim is supported, "the language of the claim must describe the invention so that one skilled in the art can recognize what is claimed." Though not discussed by the Court, this may appear to bring the §112, 2 requirement for "distinct claiming" into a §112, 1 "written description" inquiry. Further, while an adequate description may show the inventor was "in possession" of the invention, proof of "possession" does not necessarily satisfy the description requirement. Extrinsic evidence of possession does not substitute for a written description in the specification. Arguments that the deposited specimens could be routinely sequenced were rejected, because "to require the public to go to a public depository and perform experiments to identify an invention is not consistent with the statutory requirement to describe one's invention in the specification." Likewise, "a deposit is not a substitute for a written description" because the description requirement "is not satisfied by what could have been disclosed but was not."

The dissent, by Judge Dyk, argued there were triable issues of fact precluding summary judgment, disagreed that the specific hybridization of the Enzo claims was merely functional as a matter of law, and characterized the ATCC deposit as "an ideal way to satisfy the written description requirement." The decision was criticized as unfairly retroactive and inconsistent with §112, and because its practical effect is "to make description by reference to the depository impossible."

To discuss this topic further, please contact the author, Robert Schaffer, at Darby & Darby, P.C.. The information contained in this email is provided for informational purposes only and does not represent legal advice. Neither the APLF nor the author intends to create an attorney client relationship by providing this information to you through this message.


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