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Supreme Court Affirms Federal Circuit Ruling Regarding Satisfaction of Enablement Requirement

May 19, 2023

Supreme Court Affirms Federal Circuit Ruling Regarding Satisfaction of Enablement Requirement

May 19, 2023

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The Court, in a unanimous decision affirming the Federal Circuit’s holding, focused on whether the specification enabled the full scope of the invention to be practiced.

On May 18, 2023, the Supreme Court of the United States issued its opinion in Amgen, Inc. v. Sanofi, which clarified the standard of satisfying the enablement requirement, in particular, for broad functional genus claims.

Conceptual Background

LDL, or low-density lipoprotein, cholesterol is often termed “bad” cholesterol. Excessive amounts can lead to buildup of plaque in the arteries and increase the risk of developing cardiovascular disease, heart attack and stroke. The body produces LDL receptors to facilitate the removal of LDL from the bloodstream. One particular protein of interest, PCSK9, is known to bind to LDL receptors and inhibit removal of LDL. It is beneficial to target PCSK9 and inhibit its ability to interfere with LDL receptors, thereby lowering LDL levels in the body and reducing the risk of developing further disease. There are numerous drugs that target PCSK9, for example, Repatha, marketed by Amgen, and Praluent, marketed by Sanofi. Each manufacturer has a patent directed to the specific amino acid sequence of the antibody that accomplishes the PCSK9 inhibition.

Patents at Issue

Amgen owns U.S. Patent Nos. 8,829,165 (’165 patent) and 8,859,741 (’741 patent), which are directed to an entire genus of antibodies that 1) bind to specific amino acid residues on PCSK9 and 2) block PCSK9 from binding to LDL receptors. The claims thus recite a function of the antibody, rather than the specific antibody sequences that are capable of accomplishing these functions. Amgen identified the sequence of 26 antibodies that performed the claimed functions and showed the 3D structures of two of these antibodies in its patent application. In teaching how to make other antibodies, Amgen offered a “road map” method in which scientists develop a range of antibodies, investigate their binding to the specific amino acid residues of PCSK9, and determine whether any of these antibodies block PCSK9 from binding to LDL receptors. Amgen also taught a “conservative substitution” method to make other antibodies, in which an antibody performing the claimed functions has select amino acids substituted with other amino acids having similar activity. Then the binding of the modified antibody is evaluated for its performance of the claimed functions.

Case History

Amgen sued Sanofi alleging infringement of the ’165 and ’741 patents. Sanofi alleged that the patents at issue were invalid because Amgen, while identifying the 26 antibodies that perform the claimed functions, had failed to sufficiently enable one skilled in the art to make and use the entire scope of antibodies that also perform the claimed function, which would potentially cover millions of antibodies including those that have not yet been uncovered. The district court agreed with Sanofi, finding a lack of enablement. See generally Amgen, Inc. v. Sanofi, No. 14-1317, 2019 WL 4058927 (D. Del. Aug. 28, 2019). Amgen appealed to the United States Court of Appeals for the Federal Circuit, which affirmed the district court. See generally Amgen, Inc. v. Sanofi, 987 F.3d 1080 (Fed. Cir. 2021). Amgen subsequently petitioned the United States Supreme Court for certiorari, which it granted.

The Supreme Court’s Decision

While Sanofi conceded that the 26 exemplified antibodies allow a person skilled in the art to make and use these embodiments, it argued that the disputed patents do not satisfy the enablement requirement because the disclosed methods of making and uncovering antibodies do not enable the full scope of the invention. Significant trial and error would be required to reproduce the multitude of embodiments of the invention that were not disclosed but still met the functional claim limitations.

Amgen argued that in teaching the “road map” and “conservative substitution” methods of making and uncovering new antibodies having the same claimed functions in the specification, the claims are sufficiently enabled. The Court disagreed, indicating that the methods described result in “trial-and-error method[s] for finding functional antibodies” that do not help to “identif[y] a quality common to every functional embodiment,” leaving scientists “to engage in ‘painstaking experimentation’ to see what works.” Such activity would be outside of enablement and amounts to “a hunting license.” Amgen, No. 21-757 slip op. at 16-17 (quoting Brenner v. Manson, 383 U. S. 519, 536 (1966)).

The Court, in a unanimous decision affirming the Federal Circuit’s holding, focused on whether the specification enabled the full scope of the invention to be practiced. In other words, in claiming a class of process, machine, manufacture or composition of matter, the specification must enable the full scope of the claimed class. In upholding the quid pro quo bargain, the more that is claimed in a patent, the more that needs to be enabled. Based on the disputed claims in the ’165 and ’741 patents, the Court noted that claiming an entire genus of antibodies by their function would be an attempt to “monopolize an entire class of things defined by their function—every antibody that both binds to particular areas of the sweet spot of PCSK9 and blocks PCSK9 from binding to LDL receptors.” Id. at 16. This would include the 26 antibodies defined by sequence, of which there is no dispute about their enablement, and those antibodies are not disclosed in the patent and have not yet been discovered. The Court analogized its holding to prior decisions in O’Reilly v. Morse, 56 U.S. 62 (1853), The Incandescent Lamp Patent, 159 U.S. 465 (1895) and Holland Furniture Co. v. Perkins Glue Co., 277 U.S. 245 (1921) in which inventors sought to claim “all telegraphic forms of communication,” “all fibrous and textile materials for incandescence” and “all starch glues made from whatever starch happened to perform as well as animal glue,” respectively, which “would extend the monopoly beyond the invention.” Id. at 13 (quoting Holland Furniture, 277 U.S. at 258) (emphasis added).

In its decision, the Court clarified and reiterated that a patent specification does not need to disclose each and every embodiment in a claimed class, indicating that “it may suffice to give an example (or a few examples) if the specification also discloses ‘some general quality… running through’ the class that gives it ‘a peculiar fitness for the particular purpose.’” Id. (quoting Incandescent Lamp, 159 U.S. at 475). This general quality “may reliably enable a person skilled in the art to make and use all of what is claimed, not merely a subset.” Id. (citing Incandescent Lamp, 159 U.S. at 475-76). Furthermore, the Court clarified that a specification is not inadequate just because some experimentation is required. For example, preliminary tests would be required to characterize a claimed process to a particular ore of varying composition. See id. at 14 (citing Minerals Separation, Ltd. v. Hyde, 242 U.S. 261, 270 (1916)). The amount of what constitutes reasonable experimentation ultimately depends on “the nature of the invention and the underlying art.” Id. at 15 (citing Minerals Separation, 242 U.S. at 270-71).

For More Information

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