Federal Circuit Holds That Even Functional Claims Require Structural Fence Posts

In AbbVie Deutschland Gmbh v. Janssen Biotech, Inc., the Federal Circuit affirmed the district court decision that found AbbVie’s patents directed to anti-IL-12 antibodies invalid for lack of adequate written description. As between the parties, this decision leaves Centocor free to market its Stelara® product for the treatment of psoriasis. More generally, this decision emphasizes the importance of describing structurally varied species of a genus invention, even when the invention is defined  by functional characteristics. 

The AbbVie Patents at Issue

The patents at issue were AbbVie’s U.S. 6,914,128 and U.S. 7,504,485, which share the same description and claim priority to the same provisional application filed in 1999. The claims at issue in both patents are directed to antibodies that bind to human interleukin 12 (IL-12), and define the claimed antibodies by functional characteristics only. Claim 29 of the ’129 patent was treated as representative:

29. A neutralizing isolated human antibody, or antigen-binding portion thereof that binds to human IL-12 and disassociates from human IL-12 with a koff rate constant of 1 x 10-2 s-1 or less, as determined by surface plasmon resonance.

The patents describe 300 examples of antibodies that fall within the claimed genus.

The Federal Circuit Decision

The district court proceedings involved both a patent infringement action and a patent interference action. Here, we focus on the Federal Circuit’s review of the district court decision denying AbbVie’s motion for judgment as a matter of law (JMOL) after the jury rendered a verdict of invalidity for lack of adequate written description.

The Federal Circuit decision was authored by Judge Lourie and joined by Judge Chen. Judge Lourie’s opinion holds that substantial evidence supports the jury verdict that the patent claims are invalid for lacking written description, such that denial of JMOL was proper. Judge O’Malley would have reached the same outcome of invalidity on grounds of obviousness instead of written description.

In analyzing the written description requirement, the majority decision emphasizes that, under the court’s 2010 decision in Ariad, whether a disclosure meets the written description requirement for a claimed genus is fact-dependent. One factor to consider when determining if the requirement is met is the size of the genus and the specific species disclosed in the patent.

If the genus is not large or, even if it is, the specification discloses species representing the genus throughout its scope, the requirements may be met.

Judge Lourie analogizes a claimed genus to a plot of land, and described species to a house on that land.

[I]f the disclosed species only abide in a corner of the genus, one has not described the genus sufficiently to show that the inventor invented, or had possession of, the genus. He only described a portion of it.

According to Judge Lourie, if a small house is built on a corner of a large plot of land, that may not be sufficient to show that the owner has possession of the entire plot. In the same way, disclosing a small subset of species may not be sufficient to show possession of the entire genus. Although patent claims have been analogized to a fence marking the patent owner’s property, Judge Lourie notes that the written description requirement is not so easily satisfied:

With the written description of a genus … , merely drawing a fence around a perceived genus is not a description of the genus. One needs to show that one has truly invented the genus, i.e., that one has conceived and described sufficient representative species encompassing the breadth of the genus. Otherwise, one has only a research plan, leaving it to others to explore the unknown contours of the claimed genus.

Applying these principles to the case at hand, Judge Lourie explains that AbbVie’s disclosure does not demonstrate possession of the full scope of the claimed genus, i.e., all antibodies that bind IL-12 and dissociate from it with a koff rate constant of 1×10-2 s-1 or less.  While the patents describe 300 antibodies that fall within the claimed genus, they all are structurally similar to one another. That is, they have about 90% sequence homology to one another in the region that binds to IL-12, they all have VH3 heavy chains, and they all have lambda-type light chains. Thus, from a structural perspective, the described species only occupied a small corner of the claimed genus. That was not enough to satisfy the written description requirement:

In order to demonstrate that is has invented what is claimed, AbbVie’s patents must adequately describe representative antibodies to reflect the structural diversity of the claimed genus.

Under this decision, in order to have satisfied the written description requirement here, AbbVie would have had to describe antibodies more different in structure from one another, such as antibodies with greater sequence diversity, different types of heavy chains, and/or different types of light chains. This is so even though the claims define the invention in functional, not structural, terms. Indeed, the Federal Circuit warns

Functionally defined genus claims can be inherently vulnerable to invalidity challenge for lack of written description support, especially in technology fields that are highly unpredictable, where it is difficult to establish a correlation between structure and function for the whole genus or to predict what would be covered by the functionally claimed genus.

The court emphasizes that ”functionally defined claims can meet the written description requirement” but only ” if a reasonable structure-function correlation is established, whether by the inventor as described in the specification or known in the art at the time of the filing date.” Because no such correlation was evident for the claimed antibodies, the patents were invalid as failing to satisfy the written description requirement.

The Important Function of Structure

This decision joins other recent decisions where the Federal Circuit has scrutinized the specification and examples to determine what the inventors had “truly” invented. The court’s approach highlights the importance of describing species that are representative of the full scope of a claimed genus in terms of its structural diversity, even when the invention is defined in terms of functional characteristics.