CSG Law Alert: Supreme Court Affirms Lack of Enablement of Broad Genus Claims in Amgen v. Sanofi

It is imperative that all Pharmaceutical and Biotech companies review their patent portfolios in light of the enablement requirement1.  For many years, patent law has struggled with the issue of what level of teaching is necessary to enable the breadth of patent claims in the pharmaceutical and biotechnology arts. More specifically, if a patent claim is directed to a genus of compounds, how many species or sub-genus families should be taught and exemplified in a patent specification for the broader genus claim to be enabled.  The Supreme Court has answered that question in Amgen Inc. v. Sanofi, U.S., No. 21-757, opinion 5/18/23.

On May 18, 2023, The Court unanimously ruled to affirm the Federal Circuit’s ruling that Amgen’s functionally claimed genus of monoclonal antibodies are invalid for lack of enablement, with the Supreme Court noting that its decision is “entirely consistent” with the Court’s precedents.

Amgen’s patents covered monoclonal antibodies created by Amgen researchers which aid in reducing blood levels of low-density lipoprotein (LDL) – “bad cholesterol.”  One example of Amgen’s claims is Claim 29 of Patent No. 8,829,165, reproduced below:

A pharmaceutical composition comprising an isolated monoclonal antibody, wherein the isolated monoclonal antibody binds to at least two of the following residues S153, I154, P155, R194, D238, A239, I369, S372, D374, C375, T377, C378, F379, V380, or S381 of PCSK9 listed in SEQ ID NO:3 and blocks the binding of PCSK9 to LDLR by at least 80%.

In each of Amgen’s claims at issue, Amgen did not seek protection for any particular antibody described by an amino acid sequence. Instead, Amgen, successfully at the time, prosecuted claims for “the entire genus” of antibodies that (1) “bind to specific amino acid residues on PCSK9,” and (2) “block PCSK9 from binding to [LDL receptors].”(citing the underlying Fed. Cir. decision). This resulted in claims, like the one reproduced above, that covered “potentially millions more undisclosed antibodies that perform these same functions.”  Having “potentially millions” and “undisclosed” in the same sentence highlights the Justice’s thoughts here, it did not appear to be a close call.

In Amgen’s defense, they argued that the application provided a “roadmap,” describing how to generate antibodies other than the 26 antibodies expressly disclosed, and then how to test them for effectiveness.  Amgen argued this “roadmap” was enabling because it allegedly allows scientists to make and use every undisclosed but functional antibody covered by the claim.  This argument did not persuade the Court, which viewed this as just a “research assignment,” leaving scientists to engage in “painstaking experimentation” – which is not enablement.

This case emphasizes the importance of pursing claim of varying scope and patent specifications tailored to those claims.  Indeed, consideration needs to be paid to filing narrower sub-genus and species claims supported by working examples. As is typical with claiming, narrowing claims in view of prior art considerations is common, it will now be common to consider narrowing claims in view of potential enablement issues as well.

Such focused claiming would be wise based on Justice Gorsuch’s aphorism – “the more a party claims for itself the more it must enable.”  Based on the Supreme Court’s holding, a claim to the 26 antibodies expressly disclosed in the Amgen application would likely have survived an enablement challenge.


1The standard is presented in 35 U.S.C. §112(a) “[t]he specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.”