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...