The Supreme Court in Amgen Inc. v. Sanofi, 143 S. Ct. 1243 (2023) recently re-examined the requirement under 35 U.S.C. §112(a) that the specification of a patent must describe the invention "in such full, clear, concise, and exact terms as to enable any person skilled in the art . . . to make and use the [invention]." The case concerned patents covering antibodies and the specific question the Court considered was whether, in order to satisfy the enablement requirement, a patent must enable those skilled in the art to practice the full scope of the claimed invention without undue experimentation. The Supreme Court affirmed the Federal Circuit's decision that the patents at issue were invalid for lack of enablement because a patent "specification must enable the full scope of the invention as defined by its claims" and the disclosures of the Amgen patents in this case were insufficient to enable a person skilled in the art to make and use the entire class of claimed antibodies. Amgen, 143 S. Ct. at 1254.
Facts of the Amgen Case
Amgen was a patent dispute between two pharmaceutical companies, Amgen and Sanofi. The central patents at issue involved antibodies, and in the claims of those patents, Amgen claimed an "entire genus" of antibodies by describing them based on their function rather than the specific antibody structures. The issue before the Supreme Court was whether these claims were enabled by a disclosure in the specification of examples of how to make antibodies falling within the scope of the claims.
The patents at issue in the case claimed antibodies used to treat patients with high LDL cholesterol, a substance that could lead to cardiovascular diseases, heart attacks, and strokes. The antibodies performed two functions that help with removal of LDL cholesterol from the bloodstream. Amgen's patents claimed every antibody that performs these two functions, rather than describing particular antibodies by their amino acid sequence.
Amgen's patents identified 26 specific antibodies in the specification that are capable of accomplishing these two functions. The specification also disclosed two methods to allow one of ordinary skill to find other undisclosed but claimed antibodies. The first approach, referred to as the "roadmap," involves testing a variety of antibodies to determine if they can bind to the "sweet spot" of a specific protein to inhibit that protein's deleterious effect on LDL removal. The second approach, termed "conservative substitution," involves substituting specific amino acids from a known functional antibody and then testing if the resultant antibody still retains the original function. Both approaches involved testing whether a certain antibody could implement the two claimed functions. The Federal Circuit concluded that the methods disclosed would require individually screening millions of candidates with respect to multiple specific functions. Amgen Inc. v. Sanofi, Aventisub LLC, 987 F.3d 1080, 1088 (Fed. Cir. 2021).
The Supreme Court's Reasoning
The Supreme Court determined that the level of disclosure provided by Amgen's patents was insufficient to meet the enablement requirement considering the scope of the patents' claims and affirmed the decision of the Federal Circuit. Recognizing that Congress has left the enablement obligation largely intact since passing the Patent Act of 1790, the Supreme Court reaffirmed that "just as in 1790, the [enablement requirement] secures for the public its benefit of the patent bargain[.]" Amgen, 143 S. Ct. at 1251.
The Court examined the reasoning in multiple cases from the 19th and early 20th century regarding enablement. For example, in O'Reilly v. Morse, 15 How. 62 (1854), a claim covering all means of telegraphic communication was invalidated as the patent did not provide specifics on how to implement all such means; in The Incandescent Lamp Patent, 159 U.S. 465 (1895), the inventors' broad claims over all "fibrous and textile material" for an electric lamp were rejected as they failed to specify the common qualities making these materials suitable for the lamp; in Holland Furniture Co. v. Perkins Glue Co., 277 U.S. 245 (1928), a patent claim covering all "starch glue" with substantially the same properties as animal glue was contested because the patent described the key ingredient functionally and not by its physical or chemical properties, leading to the need for extensive experimentation.
According to the Supreme Court, these century-old cases mandate that "[i]f a patent claims an entire class of processes, machines, manufactures, or compositions of matter, the patent's specification must enable a person skilled in the art to make and use the entire class." Amgen, 143 S. Ct. at 1254. Although it clarified that this does not mean that the specification has to describe "how to make and use every single embodiment," and the "specification may call for a reasonable amount of experimentation," the Court found that Amgen's patents failed to meet this standard. Id. at 1254, 1255. Specifically, the Supreme Court noted that Amgen's claims may potentially cover millions of antibodies and the two methods disclosed in the specification "amount to little more than two research assignments," akin to trial-and-error methods. Id. at 1256. As a result, in this case the Court concluded that the description in the patents of 26 exemplary antibodies and two methods for how to search for additional antibodies was not enough to enable the full scope of the claims.
Impact of Amgen on Pharmaceutical Patent Litigation
Pharmaceutical patents, especially those claiming an entire genus, may be impacted by Amgen. Assessment of the claims in such patents will largely depend on their comparison to the facts of Amgen with respect to two aspects: 1) the number of both disclosed and potential (undisclosed) embodiments, and 2) the methodology described in the specification. According to the Supreme Court, Amgen was extreme by both measures. The patent disclosed only 26 embodiments out of millions claimed, and the disclosed methodology failed to spare those skilled in the art from needing to conduct "painstaking experimentation" to figure out the undisclosed embodiments. Id.
The Supreme Court's reference to "a quality common" in its discussion of The Incandescent Lamp Patent also provides insight as to the application of the enablement standard. Id. The Court suggested that the enablement requirement could be met, even if the disclosed method merely serves as a "road map" or a "conservative substitution," provided the "inventor identifies a quality common to every functional embodiment[.]" Id. In light of Amgen, patentees should look for a common quality that allows those skilled in the art to identify any undisclosed embodiments with a "reasonable amount of experimentation." Id. at 1255.
Impact of Amgen on General Patent Litigation
Amgen also amplifies the ongoing caution in patent law against overbroad functional claiming. Traditionally, patent law has discouraged claimants from functional claiming mainly through two legislative provisions: 35 U.S.C. §101, which concerns subject matter eligibility, and 35 U.S.C. §112(f), addressing 'means plus function' claims. Under §101, a claim may be found invalid if it attempts to claim and therefore preempt an entire abstract idea – this encourages patentees to avoid overbroad functional claims that do not specify concrete implementations. Under 35 U.S.C. §112(f), a claim "characterized by its function" only "cover[s] the corresponding structure, material, or acts described in the specification and equivalents thereof."
Amgen suggests that the enablement requirement can also work to curb overly broad functional claims. For instance, the ruling in Amgen reaffirms the decision of Holland Furniture, where the specification inadequately described the key component—the "starch ingredient"—by its "use or function" rather than its intrinsic properties, necessitating extensive experimentation to use or avoid the claimed discovery. The reasoning of Amgen mirrors this logic. The Court stated that the broader the claims a party asserts, the more it must demonstrate to support those claims. Id. At 1257. The analysis under 35 U.S.C. §112(a), of course, must also involve consideration of the factors described in In re Wands, 858 F.2d 731 (Fed. Cir. 1988), and will depend heavily on what particularly is disclosed in the specification. If, however, a patent specification does not recite specific structures, mechanisms, or attributes that would allow a skilled person to avoid extensive experimentation, a claim that attempts to cover an entire function may face additional risk of invalidity for lack of enablement.
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