What do telegraphic communications, incandescent lamps, wood veneering glues, and antibodies have in common? Nothing. That is of course, until May 18, 2023, when the Supreme Court ruled that Amgen’s antibody claims, like Morse’s telegraphic communication claims, Sawyer’s and Man’s incandescent lamp claims, and Perkins’ wood veneering glue claims, were invalid for lacking enablement. Although the Court did not have its own biologic or even life science-related precedent to rely upon, the Court found similarities in its previous decisions involving these disparate technologies. According to the Court, for example, “[m]uch as Morse sought to claim all telegraphic forms of communication, Sawyer and Man sought to claim all fibrous and textile materials for incandescence, and Perkins sought to claim all starch glues that work as well as animal glue for wood veneering, Amgen seeks to claim ‘sovereignty over [an] entire kingdom’ of antibodies.” Amgen Inc. v. Sanofi, No. 21-757, 2023 WL 3511533, at *10 (U.S. May 18, 2023) (quoting Consol. Elec. Light Co v. McKeesport Light Co, 159 U.S. 465 at 475). And according to the Court, “[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 Inc., 2023 WL 3511533, at *9. But what does it mean to enable an “entire class”?
Let’s first consider the technology and claims at issue. The Amgen case involves antibodies that bind to specific amino acid residues on the PCSK9 enzyme. PCSK9 mediates the degradation of the low-density lipoprotein cholesterol receptor (LDLR), which leads to increased levels of circulating LDL. Amgen and Sanofi both market antibodies that bind to PCSK9 and block PCSK9 from interacting with LDLR, leading to a decrease in the levels of circulating LDL. Id. at *4-5. The claims at issue are not directed to the amino acid sequence of Amgen’s antibody. Rather, the claims are functional genus claims – they specify where the antibody binds on PCSK9 and specify that binding of the antibody to PCSK9 blocks binding of PCSK9 to LDLR. Claim 19 of U.S. Patent No. 8,829,165, and the independent claim from which it depends, are as follows:
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.
19. The isolated monoclonal antibody of claim 1, wherein the isolated monoclonal antibody binds to at least two of the following residues S153, I154, P155, R194, D238, A239, I369, S372, D374, C375, T377, C378, F379, V380, or S381 of PCSK9 listed in SEQ ID NO:3.
The patents disclose the amino acid sequence of 26 antibodies that fall within the scope of the claimed genus. The exact size of that genus, however, was up for debate. During oral arguments, for example, Amgen’s counsel argued that 384 antibodies could be produced by the patent’s “roadmap.” Sanofi’s counsel disputed this number and argued that millions of antibodies could fall within the scope of the claims. The Court sided with Sanofi, stating that “[t]he record reflects that this 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.” Amgen, 2023 WL 3511533, at *10. According to the Court, “Amgen seeks to claim ‘sovereignty over [an] entire kingdom’ of antibodies.” Id. at *10.
The Court next considered the amount of experimentation that would be required for one of skill in the art to make the “vast number of” claimed antibodies. Amgen asserted that scientists could make additional antibodies that fall within the claim scope by following one of two methods described in the patents – one that Amgen referred to as “the roadmap” and the other involving making conservative substitutions in the antibodies. Id. at *1. But the Court was not persuaded that these methods would enable one of skill in the art to make and use the class of antibodies without undue experimentation. According to the Court, Amgen’s proposed methods “amount to little more than two research assignments”:
These two approaches amount to little more than two research assignments. The first merely describes step-by-step Amgen’s own trial-and-error method for finding functional antibodies – calling on scientists to create a wide range of candidate antibodies and then screen each to see which happen to bind to PCSK9 in the right place and block it from binding to LDL receptors. . . The second isn’t much different. It requires scientists to make substitutions to the amino acid sequences of antibodies known to work and then test the resulting antibodies to see if they do too – an uncertain prospect given the state of the art.
Id. at *10. The Court viewed these methods as forcing scientists to engage in “painstaking experimentation” to see what works, and referred to the level of disclosure as “a hunting license,” not an enabling disclosure. Id. And so the Court “agree[d] with the lower courts that Amgen has failed to enable all that it has claimed, even allowing for a reasonable degree of experimentation.” Id.
So what does it mean to enable one of skill in the art to make and use an “entire class” of processes, machines, manufactures, or compositions of matter? The Court declined to place any bright line rules on the number of examples needed to satisfy the enablement requirement, leaving each case to be decided on its own facts and stating that “the more a party claims, the broader the monopoly it demands, the more it must enable.” Id. at *10. But the Court does provide us with some takeaways.
A specification need not always describe how to make and use every embodiment. Although the Court agreed with the Federal Circuit that “the specification must enable the full scope of the invention as defined by its claims” (id. at *9), it did make it clear that a specification need not always describe how to make and use every embodiment. According to the Court:
That is not to say a specification always must describe with particularity how to make and use every single embodiment within a claimed class. 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.” Incandescent Lamp, 159 U. S., at 475. 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. See id., at 475–476.1
Amgen, 2023 WL 3511533, at *9.
Disclosing a general quality of the claimed genus may assist with enablement. The Court indicated that disclosing a “general quality” of the genus may help to provide enablement. Could, for example, requiring a consensus complementarity-determining region (CDR) sequence or specific amino acid residues of the antibody provide enough of a “general quality” to satisfy the enablement requirement for a genus of antibody molecules?
Claims may be enabled even if a reasonable amount of experimentation is needed to make and use the claimed invention. The Court confirmed that a specification is not necessarily “inadequate just because it leaves the skilled artist to engage in some measure of adaptation or testing.” Id. And consistent with the Federal Circuit decisions, the Court confirmed that “reasonableness in any case will depend on the nature of the invention and the underlying art.” Id. Although the Court declined to set any bright line rules regarding the amount of experimentation that would be considered undue, it acknowledged that enablement is very fact dependent. For example, the level of disclosure needed to enable a broad antibody claim is likely different than the level of disclosure needed to enable a broad siRNA or oligonucleotide claim. And the level of disclosure needed to enable a biologic or small molecule will likely be different from the level of disclosure needed to enable a mechanical device.
Functional genus claims are not dead. The Court did not agree with Amgen’s argument that the Federal Circuit raised the bar for enablement of claims that encompass an entire genus that is defined by its function. According to the Court, [i]nstead, we understand that [the Federal Circuit] to have recognized only that the more a party claims for itself the more it must enable.” Id. at *11. Although we are left with uncertainty regarding just how much enablement is required, the Court has left open the possibility of claiming a genus based on its function.
The Court’s enablement decision echoes the Federal Circuit’s recent written description decisions. Specifically, both enablement and written description must be shown for the “full scope” of the claims. Time will tell if applicants can find a way to draft broad genus claims in the biological and chemical arts that pass the “full scope” requirements.