In 2001, the U.S. Patent and Trademark Office (USPTO) issued a written description guideline in which it specified that one of skill in the art would have recognized that the spectrum of antibodies which bind to antigen X were implicitly disclosed as a result of the isolation of antigen X.
As a result, a number of cases were decided on the basis that as long as an applicant had disclosed a “fully characterized antigen” either by its structure, formula, chemical name, or physical properties, of by depositing the protein in a public depository, the applicant could claim an antibody by its binding affinity to that described antigen.
In 2017, the case Amgen v. Sanofi (Fed. Cir. 2017) was decided, and everything changed.
The Federal Court rejected the antibody exception to the written description requirement and held that identifying an epitope is not, by itself, enough to satisfy the written description requirement. Thus, following this decision, on February 22, 2018 the USPTO issued a memorandum stating that “in view of the Amgen decision, adequate written description of a newly characterized antigen alone should not be considered adequate written description of a claimed antibody to that newly characterized antigen, even when preparation of such an antibody is routine and conventional.”
Rather, according to the USPTO, the examiners should apply the conventional tests for written description spelled out in Ariad Pharmaceuticals, Inc. v. Eli Lilly and Co., No. 2008-1248, slip op. (Fed. Cir. March 22, 2010) which held that, “while written description is judged based on the state of the art as of the priority date, evidence showing that a claimed genus does not disclose a representative number of species may include evidence of the species…that post-date the priority date.”
So, what can be done now?
First, it would be good practice starting with claims covering the reference product and then consider designing-around options. For example, if possible, define the antibody by structure, epitope, and function/use. And of course, make sure that data is included in the specification to support all these types of claims.
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Silvia Salvadori, PhD