United States: Court Reverses Itself on Whether Biotech Material in Public Depository May Satisfy Written Description Requirement

The U.S. Court of Appeals for the Federal Circuit has now reversed its recent decision (reported in IP Update, Vol. 5, No. 4) holding a patent owned by Enzo BioChem invalid for failure to comply with the written description requirement of U.S. patent law. In its new decision, the Federal Circuit found compliance with the written description requirement based on a public deposit of a claimed nucleutide sequence. Enzo Biochem, Inc. v. Gen-Probe Inc., Case # 01-1230 (July 15, 2002).

In reversing its earlier decision, the Federal Circuit adopted the U.S. Patent and Trademark Office’s (PTO) standard for determining compliance with the written description requirement. The court noted that under the PTO’s guidelines, the written description requirement would have been met for all of the claims at issue if the disclosed functional characteristics of preferential binding of the claimed nucleic acids were coupled to a disclosed correlation between that function and a structure that is sufficiently known or disclosed. In this case, Enzo’s deposited materials were incorporated by reference in the specification, leading the court to conclude that "[t]he sequences are thus accessible from the disclosure in the specification," thereby satisfying the written description requirement.

The Court continued, "Whether reference to a deposit of a nucleotide sequence may adequately describe that sequence is an issue of first impression in this court. In light of . . . the practical difficulties of describing unique biological materials in a written description, we hold that reference in the specification to a deposit in a public depository . . . constitutes an adequate description of the deposited material sufficient to comply with the written description requirement [of Patent Act section 112, para. 1]"

In holding that Enzo had raised a genuine issue of material fact as to whether a reasonable fact-finder could conclude that the claimed sequences are adequately described by their ability to hybridize to nucleic acid molecules that, although not sequenced, are available to the public, the Federal Circuit noted that under the PTO guidelines "functional claiming is permissible when the claimed material hybridizes to a disclosed substrate."

Two of Enzo’s arguments that were dismissed by the court are worth noting. Enzo had argued that the written description requirement for the generic claims is met as a matter of law because the claim language appears word for word in the specification. In rejecting this argument, the Court held that regardless of whether claim language appeared as an original claim or is present in the specification, the language must convey an adequate description of the invention. "[A] claim does not become more descriptive by its repetition, or its longevity."

The Court also dismissed Enzo’s argument that the written description requirement is met by a showing of possession of the claimed invention, in this case biological deposit of sequences within the scope of the claims, because "it does not by itself provide a written description in the patent specification." (emphasis in the original). Even for biological inventions, "Compliance with the written description requirement is grounded on the fact of the deposit and the accession number in the specification, not because a reduction to practice has occurred." The Federal Circuit remanded the case for a determination of whether Enzo is entitled to the full scope of the claims on the basis of the deposit of a few sequences and the disclosed functional ability of the claimed genus of sequences to hybridize to the deposited sequences, specifically advising the lower court to follow the PTO’s guidelines.

Practice Note: Breathe a sigh of relief and wait for the next installment when the Court determines whether the deposit of a few nucleic acids, coupled to functional language in the specification describing the ability of claimed sequences to specifically hybridize under specified conditions to the deposited nucleic acids, provides sufficient written description for a broad genus of sequences.