On Feb. 11, 2021, Federal Circuit affirmed District Court and found two Amgen patents invalid under lack of enablement.

Background:

Amgen sued Sanofi/Regenron in Oct. 2014 for infringement of US 8,829,165 and US 8,859,741 patents.  These patents are related to antibodies that purportedly bind to the one or more of 15 amino acids of PCSK9 protein and lower LDL levels by blocking PCSK9 from binding to LDL receptors. During trial, the district court granted JMOL
of nonobviousness and of no willful infringement. At the close of the trial, the jury determined that the patents
were not shown to be invalid for lack of enablement and written description. During appeal, federal Circuit remanded case back to district court for new trial with respect to enablement and written description issues. On remand, the parties tried the issues of written description and enablement to the jury. The jury again found that Sanofi failed to prove that the asserted claims were invalid for lack of written description and enablement. Sanofi moved for JMOL and, in the alternative, for a new trial. The district court granted Sanofi’s Motion for JMOL for lack of enablement and denied the motion for lack of written description. Amgen appealed.

Federal Circuit analysis:

During appeal, Amgen argued that the embodiments in the patent are structurally representative for the purpose of fulfilling the written description requirement, and such evidence is sufficient to indicate a structure/function correlation establishing enablement. Sanofi contended that there are millions of antibody candidates within the scope of the claims, the disclosures do not provide sufficient guidance, antibody generation is unpredictable, and practicing the full scope of the claims requires substantial trial and error. According to Sanofi, the functionally defined claims cover a vast scope. Federal Circuit said that the enablement inquiry for claims that include functional requirements can be particularly focused on the breadth of those requirements, especially where predictability and guidance fall short. In particular, it is important to consider the quantity of experimentation that would be required to make and use, not only the limited number of embodiments that the patent discloses, but also the full scope of the claim. Each appealed claim in this case is a composition claim defined, not by structure, but by meeting functional limitations. Although the specification provides some guidance, including data regarding certain embodiments, but “after considering the disclosed roadmap in light of the unpredictability of the art, any reasonable factfinder would conclude that the patent does not provide significant guidance or direction to a person of ordinary skill in the art for the full scope of the claims.”

District court correctly noted that, the only ways for a person of ordinary skill to discover undisclosed claimed embodiments would be through either “trial and error, by making changes to the disclosed antibodies and then screening those antibodies for the desired binding and blocking properties,” or else “by discovering the antibodies de novo” according to a randomization-and-screening “roadmap.” Thus, the required experimentation “would take a substantial amount of time and effort.” Therefore, the asserted claims are invalid for lack of enablement.