Amgen Inc. v. Sanofi

Background

Two pharmaceutical companies developed antibody drugs that lower “bad” LDL cholesterol by inhibiting a natural protein called PCSK9. Amgen first patented a specific antibody in 2011 and later obtained 2014 patents that claimed the entire class of antibodies that (1) bind certain PCSK9 amino acids and (2) block PCSK9 from binding LDL receptors. Amgen disclosed the amino acid sequences of 26 antibodies and described two methods—called the “roadmap” and “conservative substitution”—for making more. Sanofi was sued for infringement and argued those broader claims were invalid under the law’s enablement requirement, which requires a patent to teach how to make and use what is claimed. Lower courts ruled for Sanofi.

Reasoning

The Court had to decide whether Amgen’s patent description enabled a person skilled in the field to make and use the entire class of antibodies Amgen claimed. Relying on the long-standing patent ‘‘bargain’’ and precedents about overbroad claims, the Court concluded Amgen’s roadmap and substitution methods amounted to trial-and-error research and did not reliably teach how to create the vast number of antibodies its claims covered. Because Amgen claimed a huge functional class but taught only limited examples, the patents failed the enablement requirement and were therefore invalid. The Supreme Court affirmed the lower courts’ judgments.

Real world impact

The decision prevents Amgen from monopolizing a broad universe of PCSK9-targeting antibodies based on limited examples. It clears the way for competitors to develop alternative antibody drugs without being blocked by these particular broad claims, and it reinforces that patent applicants claiming wide functional classes must provide detailed guidance so others can make and use the full claimed inventions.