The Supreme Court denied certiorari last week in Amgen Inc. v. Sanofi, in a case that asked the Court to review the Federal Circuit's jurisprudence related to the written description requirement of 35 U.S.C. § 112(a).
To recap, the Federal Circuit overturned the "newly characterized antigen test" set forth in Noelle v. Lederman and brought treatment of the written description requirement for antibody claims in line with the Court's en banc decision in Ariad v. Eli Lilly. The case arose when Amgen sued Sanofi and Regeneron for over its Praluent® (alirocumab) product that could compete with Amgen's Repatha™ (evolocumab); Amgen's asserted patents, inter alia, included U.S. Patent Nos. 8,829,165 ("'165 patent") and 8,859,741("'741 patent"), functionally claim a genus of antibodies that encompass Sanofi's Praluent® product. As background, blood plasma contains low-density lipoproteins that bind cholesterol and are associated with atherosclerotic plaque formation. Liver cells express receptors for LDL (LDL-R) wherein binding thereto reduces the amount of LDL cholesterol in blood and reduces the risk of plaque formation and cardiovascular disease. PCSK9 (proprotein convertase subtilisin kexin type 9) is a molecule that binds to and causes liver cell LDL-R to be destroyed, thus reducing the capacity and effectiveness of the liver cell's ability to reduce serum LDL-cholesterol. The antibodies at issue in this suit bind to PCSK9 and prevent PCSK9 from binding to LDL-R, causing their destruction.
Claim 2 of the '165 patent (dependent on claim 1, the limitations of which are included in italics) was asserted by Amgen in the litigation:
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 LDL[-]R, wherein the monoclonal antibody binds to at least S153.
It is important to note that, while reciting the structure of the residues on PCSK9 that are bound by the claimed antibody, the claim does not recite any structural limitations of the antibody. The only antibody characteristics recited as limitations are functional, i.e., the ability to bind to at least one of the recited PCSK9 residues and block binding of PCSK9 to LDLR.
The panel decision, by Chief Judge Prost, joined by Judges Taranto and Hughes, held that an adequate written description of a genus requires the specification to disclose "a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one of skill in the art can 'visualize or recognize' the members of the genus." The panel held that the jury instructions, which relied on Noelle v. Lederman for the proposition that characterizing a new antigen was sufficient to satisfy the statute for claims encompassing a broad genus of antibodies that could bind to the new antigen, "is not legally sound and  not based on any binding precedent" and provided its legal analysis of Enzo Biochem, Inc. v. Gen-Probe Inc., 323 F.3d 956 (Fed. Cir. 2002), Noelle v. Lederman, 355 F.3d 1343 (Fed. Cir. 2004), and Centocor Ortho Biotech, Inc. v. Abbott Labs., 636 F.3d 1341 (Fed. Cir. 2011) in support of its conclusion. The panel held this instruction to be improper because it effectively eliminated the written description requirement from the statute in favor of enablement, contrary to the Court's en banc Ariad decision, stating that "[b]y permitting a finding of adequate written description merely from a finding of ability to make and use, the challenged sentence of the jury instruction in this case ran afoul of what is perhaps the core ruling of Ariad." And the panel found that whether the relationship between the structure of the antigen, no matter how fully characterized, and any of its cognate antibodies is (here and hitherto) "hotly contested" which precluded the Court from making any definitive finding. The panel recited its abrogation of the "fully characterized antigen" test more directly:
Further, the "newly characterized antigen" test flouts basic legal principles of the written description requirement. Section 112 requires a "written description of the invention." But this test allows patentees to claim antibodies by describing something that is not the invention, i.e., the antigen. The test thus contradicts the statutory "quid pro quo" of the patent system where "one describes an invention, and, if the law's other requirements are met, one obtains a patent." Indeed, we have generally eschewed judicial exceptions to the written description requirement based on the subject matter of the claims [citations omitted].
In its certiorari petition, Amgen submitted this Question Presented:
Whether the standard for determining the adequacy of the "written description of the invention" should be as the statute says—that the description must be "in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains . . . to make and use the same"—or whether court-created standards should control instead.
Amgen asserted a number of reasons for the Court's review. Amgen argued that the Federal Circuit's "possession" test for satisfying the written description requirement is contrary to the statutory language, the statute's history, and Supreme Court and lower court precedent. The petition analyzed the statutory test, finding that the statute's structure mandates that the statute requires a written description of the invention in a manner that discloses how to make and use it. The brief argued that the Federal Circuit's "'possession' jurisprudence has strayed too far from the statutory standard, imposes extra-statutory barriers to patent protection, and has resulted in a shifting array of uncertain sub-tests and evidentiary considerations that destabilize the incentives and certainty needed to drive the development of breakthrough inventions." In Amgen's view, the statute contains a single written description requirement that the Federal Circuit has split into two, separating the "written description" requirement from the "enablement" requirement, each having different standards. This bifurcation "defies the statute and precedent," according to the petition. Throughout the brief, Amgen contrasted the relatively certain methodology to ascertain whether the enablement requirement has been satisfied with the more "nebulous" requirement for satisfying written description (caused by the factual nature of the written description inquiry). Using the Federal Circuit's own precedent, the petition called out a number of "subtests" used by the Federal Circuit to address this question, including the "representative-species" test, "structure-function" test, and "common-structural-features" test, none of which, Amgen argued, can be reconciled with the statutory text. The brief also relied on a number of dissenting opinions by Federal Circuit judges (including in the en banc Ariad decision) and academic criticism to support its allegations that the Federal Circuit erred in its application of the written description requirement of § 112(a). The brief also pointed to the "ever-shifting" nature of the Court's decisions, culminating in overturning the Noelle v. Lederman test in the case at bar, arguing that:
The Federal Circuit's departure from § 112(a)'s standard—and the bargain the Patent Act provides—has become intolerable. It does not promote research and investment required for the breakthrough inventions most deserving of patent protection; instead, incentives are shifted to narrow advances for which narrow patents can be obtained under the Circuit's sub-tests. The ever-evolving application of the "possession" standard has produced jurisprudential anarchy, leaving inventors uncertain whether disclosures are sufficient.
The petition also contained a section directed to the purported importance (on policy grounds) of the question presented, putative negative effects on innovation, dissension amongst Federal Circuit judges over the recognition of a separate written description requirement, and the disparate effects on biotechnology inventions.
Sanofi's responsive brief provided several reasons why the Supreme Court should not grant cert. First, the brief argued that this case was an "exceptionally poor candidate for certiorari," at least because the issue underlying the Question Presented was not raised by the parties below or addressed by the Federal Circuit (the Supreme Court is "a court of review, not of first view," according to the brief, citing Byrd v. United States, 138 S. Ct. 1518, 1527 (2018)). This argument was supported by Amgen's positions, in this case and as amicus in, inter alia, the Federal Circuit's Ariad decision, supporting the Federal Circuit's decisions on written description. Under these circumstances, Sanofi argued that the Court should consider the issue waived by Amgen. Raising judicial economy principles, the brief also argued that even if the Court granted certiorari and decided the case, its judgment was not dispositive (because the Federal Circuit remanded for the District Court to reconsider Sanofi's enablement challenge based on post-arising evidence the District Court "improperly excluded") and that the case remained ongoing below. Turning to stare decisis, the brief argued that there was no reason for the Court to "disrupt more than fifty years of settled precedent" by reviewing the Federal Circuit's written description case law. Sanofi asserted that the Federal Circuit had come to the right conclusions in how its written description jurisprudence had developed, and again asserted to the Court that Amgen had "vastly overstate[d]" the importance of the Question Presented.
It is impossible to know, of course, why the Supreme Court decides whether or not to grant cert. Whether this decision signals a lessening of the Supreme Court's interest in deciding patent law cases, what we do know is that the Court will not yet be reviewing how the Federal Circuit applies the written description requirement to antibody claims.