Amgen v. Sanofi: The Supreme Court Takes On Enablement

“If 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. In other words, the specification must enable the full scope of the invention as defined by its claims. The more one claims, the more one must enable.”

The Supreme Court issued a unanimous decision in Amgen v. Sanofi, ruling that Amgen’s patents directed to an antibody that is binds to specific regions of a target and blocks the target from binding to another protein are invalid as lacking enablement.

Case Background and Technology

The patents at issue relate to antibodies that help reduce levels of low-density lipoprotein cholesterol (LDL). LDL binds to LDL receptors (LDLR), which help extract and remove LDL from the bloodstream. The protein PCSK9 is known to bind and degrade LDLR. Thus, ongoing research explores inhibition of PCSK9 binding to LDLR, which increases availability of the LDLR to remove LDL that in turn results in an overall reduction of LDL.

Amgen and Sanofi independently developed antibodies with unique amino acid sequences, both of which block PCSK9 from binding to LDLR. Amgen obtained the two patents at issue, US 8,829,165 and US 8,859,741, directed to a genus of antibodies with the following functions: (i) bind to specific amino acid residues of PCSK9; and (ii) block PCSK9 from binding to LDL receptors. Claim 1 of each patent is representative:

Claim 1 of the ‘165 patent recites:

1. An isolated monoclonal antibody, wherein, when bound to PCSK9, the monoclonal antibody binds to at least one of the following residues: S153, I154, P155, R194, D238, A239, I369, S372, D374, C375, T377, C378, F379, V380, or S381 of SEQ ID NO:3, and wherein the monoclonal antibody blocks binding of PCSK9 to LDLR.

Claim 1 of the ‘741 patent recites:

1. An isolated monoclonal antibody that binds to PCSK9, wherein the isolated monoclonal antibody binds an epitope on PCSK9 comprising at least one of residues 237 or 238 of SEQ ID NO: 3, and wherein the monoclonal antibody blocks binding of PCSK9 to LDLR.

The specifications of the ‘165 and ‘741 patents are identical and identify amino acid sequences, i.e., structure, of 26 antibodies that perform the two required functions. The specification also provides two methods for scientists to make other such antibodies: “roadmap” and “conservative substitution.” The “roadmap” method involves generating antibodies, determining if the antibodies have the desired binding properties to PCSK9 such that PCSK9 binding to LDLR is blocked. The “conservative substitution” method involves replacing select amino acids of an antibody known to perform the prescribed functions with other amino acids of similar properties, then testing the resulting antibody to determine if it still performs the prescribed functions.

Shortly after obtaining the ‘165 and ‘741 patents, Amgen sued Sanofi for infringement. Sanofi countered the claims are invalid for lack of enablement, asserting that Amgen’s claims covered potentially millions more undisclosed antibodies that perform the same functions. Sanofi also stated that neither of Amgen’s methods enable a person skilled in the art to reliably generate additional antibodies, because the “methods require scientists to engage in little more than trial-and-error process of discovery.” The district court ruled in favor of Sanofi, and this decision was affirmed by the Federal Circuit and upheld by the Supreme Court.

The Telegraph, the Lamp and the Starch Glue

The Supreme Court referenced three of its prior enablement cases in which the patent claims were found to lack enablement:

(1) O’Reilly v. Morse, 15 How. 62 (1854), in which the patent at issue attempted to claim “the use of the motive power of the electric or galvanic current … however developed for marking or printing intelligible characters, signs, or letters, at any distances”;

(2) The Incandescent Lamp Patent, 159 U. S. 465 (1895), in which the patent at issue attempted to claim “an electric lamp with an incandescing conductor made of carbonized fibrous or textile material, which was an improvement over conductors made of mineral or gas carbon”; and

(3) Holland Furniture Co. v. Perkins Glue Co., 277 U. S. 245 (1928), in which the patent at issued attempted to claim “all starch glue which, when combined with about three parts or less by weight of water, will have substantially the same properties as animal glue.”

Amgen Decision

Upon applying these prior rulings, the Supreme Court found Amgen’s claims “seek to monopolize an entire class of things defined by their function.” The Supreme Court stated that the claimed “class of antibodies does not include just the 26 that Amgen has described by their amino acid sequences, but a ‘vast’ number of additional antibodies that it has not.”

The Supreme Court qualified they are not ruling that “a specification always must describe with particularity how to make and use every single embodiment within a claimed class,” stating:

For instance, 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.” In some cases, disclosing that general quality may reliably enable a person skilled in the art to make and use all of what is claimed, not merely a subset. Nor is a specification necessarily inadequate just because it leaves the skilled artist to engage in some measure of adaptation or testing.

However, the Supreme Court found that Amgen’s “roadmap” and “conservative substitution” methods were insufficient for enablement, stating that these methods “amount to little more than two research assignments,” and that they force the scientist to “engage in ‘painstaking experimentation’ to see what works.” The Supreme Court held that Amgen’s claims are non-enabled.

Amgen provided three alternative arguments, i.e., that the Federal Circuit erred in conflating whether an invention is enabled with how long it may take a person skill in the art to make every embodiment; that the Federal Circuit erroneously raised the bar for enablement; and that affirmance risks destroying incentives for breakthrough inventions. In response, the Supreme Court agreed with the Federal Circuit’s conclusion that specifically stated that it does not hold that “effort required to exhaust a genus is dispositive”; that the Federal Circuit’s standard for enablement is consistent with the statutory standard; and that striking a proper balance between incentivizing inventors and ensuring the public receives the full benefit of innovations is a policy judgment, and the enablement mandate applies the desired balance.

Aftermath and Takeaways

The USPTO issued a guidance on January 10, 2024, in light of this decision. The USPTO addressed In re Wands, 858 F.2d 731 (1988), the predominant precedent regarding enablement, discussion of which was noticeably absent in the Supreme Court decision. According to the guidance, “USPTO personnel will continue to use the In re Wands factors to ascertain whether the amount of experimentation required to enable the full scope of the claimed invention is reasonable.”

While this is the first time in decades that the Supreme Court has issued a ruling on enablement, the decision does not necessarily change current practice with regard to antibody claims. The courts have already held that antibody claims do not satisfy the written description requirement if they are only described by their function, e.g., ability to bind a particular antigen. The Amgen decision complements the requirement for adequately describing the structure of the antibody, with the additional requirement that one of ordinary skill in the art must not be required to engage in “painstaking experimentation” to find antibodies meeting the functional limitations.

“Guidelines for Assessing Enablement in Utility Applications and Patents in View of the Supreme Court Decision in Amgen Inc. et al. v. Sanofi et al.,” A Notice by the United States Patent and Trademark Office on January 10, 2024. Accessible at https://www.federalregister.gov/documents/2024/01/10/2024-00259/guidelines-for-assessing-enablement-in-utility-applications-and-patents-in-view-of-the-supreme-court.