Solutions to the Problem of Therapeutic Antibody Genus Claims

This article was featured in the AIPLA Quarterly Journal – Volume 52, Number 3, Page 513, Summer 2024.

Court interpretations of the enablement and written description requirements of 35 U.S.C. § 112(a) have led to the erosion of legal support for the patentability and survival of genus claims for therapeutic antibodies and their uses. Most recently, the Federal Circuit in Amgen v. Sanofi (2021) applied a trio of chemical molecule precedents, Wyeth v. Abbott (2013), Enzo Life Sciences v. Roche (2019), and Idenix v. Gilead (2019) to deny enablement of a genus of antibodies claimed in quasi-chemical format. In affirming the Amgen decision in 2023, the Supreme Court added a “common quality” requirement for enablement of such claims. Analysis of claim requirements shows that, in most instances when the Federal Circuit has evaluated a genus claim to an antibody per se having blocking or biological requirements or to a method of therapy using such antibody, the Court held that such claim lacked either full scope enablement or full scope written description.

This Article evaluates and proposes several solutions for the difficult task of obtaining and defending antibody genus claims. When a new target is discovered –that is, the target is unknown– and a novel antibody is generated against it, it should be possible under Chiron v. Genentech (2004) to put forth a per se antibody genus claim with no requirements other than a simple binding definition. Even if the target is known and the invention is that blocking such target leads to a heretofore unbeknownst method of therapy then, following the format in Hopkins v. CellPro (1998), an antibody genus can be claimed in per se form by a binding definition plus a competitive binding requirement relative to a specifically identified reference antibody. Such a claim is akin to an immunoassay claim, which under In re Wands (1988) and Hopkins, is more readily enabled and described than a claim with blocking or biological requirements. This is particularly the case when using today’s state of the art high-throughput screening immunoassays enhanced by artificial intelligence. Other promising formats, such as means plus function claims are also evaluated.

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