AbbVie owns US 6,914,128 (’128), which covers a variety of anti-IL12 monoclonal antibodies. AbbVie markets an anti-IL12 monoclonal (viz. Humira®) as a treatment for a variety of auto-immune disorders, including psoriasis. Centocor also markets an anti-IL12 monoclonal antibody (viz. Stelara®) for treating psoriasis. Claim 29 of ’128 claims “[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 1×10-2 s-1 or less, as determined by surface plasmon resonance.”
AbbVie sued Centocor for infringement of ’128 Claim 29. There was no dispute that Stelara® comes within the literal scope of ’128 Claim 29, so the trial mostly concerned validity. The U.S. District Court for the District of Massachusetts ruled that Claim 29 was invalid for lack of written description, lack of enablement, and obviousness. The Federal Circuit afﬁrmed the judgment, concluding speciﬁcally that Claim 29 lacked adequate written description.
Judge Lourie’s method of written description analysis was noteworthy for its clarity and incisiveness. He began his analysis by noting (slip op. at 22) that there are at least two sorts of disclosure that will satisfy the written description requirement when claiming a genus of biomolecules: “either  a representative number of species falling with the scope of the genus or  structural features common to the members of the genus so that one of skill in the art can ‘visualize or recognize’ the members of the genus” (quoting Univ. of Calif. v. Eli Lilly & Co., 119 F.3d 1559, 1568–69 (Fed. Cir. 1997)). AbbVie had admitted at trial that the ’128 speciﬁcation did not satisfy option 2, so the question on appeal was whether a reasonable jury could conclude from the facts of record that ’128 lacked disclosure of a representative number of species to support the generic claim.
The essence of the “representative number of species” approach is that the species disclosed must embody the full range of variation that exists within the claimed genus. It is not enough (slip op. at 23) just to “point out and distinctly circumscribe the outer boundaries of a claimed invention.” Rather, one must describe species sufﬁcient to show possession of the entire genus—not just one sub-genus within the broader genus. Judge Lourie reasoned (slip op. at 24 & 25) that because the asserted claim covers the allegedly infringing product, one must be able to ﬁnd at least one species described in the speciﬁcation that is structurally similar to the allegedly infringing product in order for Claim 29 to be supported by adequate written description.
Centocor had presented the jury with the following table, summarizing the structural differences between Stelara® and speciﬁc antibodies described in ’128 (viz. J695 and Joe-9).
Because written description is a question of fact, reviewed for substantial evidence, it was comparatively easy for the Federal Circuit to afﬁrm the jury’s verdict in view of this table of factual evidence.
Obviously the ’128 speciﬁcation disclosed possession of J695, whose CDRs were disclosed by amino acid sequence. It was hardly unreasonable, however, for the jury to conclude that the ’128 speciﬁcation did not convey possession of Stelara®. Although Judge Lourie was careful to note (slip op. at 25) that “AbbVie’s patents need not describe the allegedly infringing Stelara in exact terms…, the patents must at least describe some species representative of antibodies that are structurally similar to Stelara.” The jury had heard evidence that Stelara® had no more than 50% sequence similarity to the antibodies described in ’128, and that Stelara® used a different heavy-chain variable family and a different light chain type than any antibody described in ’128. In other words, there were signiﬁcant structural differences between Stelara® and the species described in ’128. Therefore, the Federal Circuit concluded that the jury’s verdict was supported by substantial evidence.
Judge O’Malley wrote a concurrence, opining that Judge Lourie’s written description analysis was all merely dicta. Judge O’Malley considered (slip op. at 2) that because AbbVie had not appealed the trial court’s conclusion of obviousness, the judgment below could be afﬁrmed on the uncontested obviousness grounds. Nevertheless, even if Judge Lourie’s opinion is mostly dicta, the written description analysis that he employed provides a more clear and simple approach to written description law that patent prosecutors and their clients should welcome.
Practice tip. MPEP §2163.II.A.3(a)(ii) says that “[t]he written description requirement for a claimed genus may be satisﬁed through sufﬁcient description of a representative number of species…” Although the word “may” implies that there are other ways to satisfy the requirement, the quoted portion of the MPEP does not specify any. AbbVie v. Centocor helpfully reafﬁrms that in addition to “representative number of species,” one can resolve a written description rejection by pointing to a description in the speciﬁcation of “structural features common to the members of the genus…”