USPTO Memorandum – Written Description Guidance for Antibody Claims

In light of the decision by the Federal Circuit in Amgen v. Sanofi,¹ the USPTO issued a two-page Memorandum² to the Patent Examining Corps “to clarify the applicability of USPTO guidance regarding the written description requirement of 35 U.S.C. §112(a)” as it applies to antibodies.

The Memorandum refers to the decision in Amgen, in which “[t]he Federal Circuit [explains] that when an antibody is claimed, 35 U.S.C. §112(a) requires adequate written description of the antibody itself” such that the “‘newly characterized antigen’ test, which had been based on an example in USPTO-issued training materials…should not be used in determining whether there is adequate written description under 35 U.S.C. §112(a) for a claim drawn to an antibody.” The Memorandum concludes that “[i]n 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” and indicates that the Amgen decision will be added to the MPEP.

The Memorandum points out that the 2008 Written Description Training Materials are outdated and should not be relied upon as reflecting the current state of the law regarding 35 U.S.C. §§ 101 and 102. Rather, the Memorandum indicates that USPTO personnel should continue to follow the guidance in the MPEP regarding written description (MPEP 2161.01 and 2163), “except insofar as MPEP 2163 indicates that disclosure of a fully characterized antigen may provide written descriptive support of an antibody to that antigen.” The Memorandum repeats that the MPEP will be updated to reflect the changes in the law regarding Written Description support for antibody claims.