by Dennis Crouch
Amgen Inc. v. Sanofi-Aventis (Fed. Cir. 2021)
Patent claims typically cover an infinite number of potential infringing embodiments. This seemingly renders true full-scope enablement an impossible task. But the metaphysics are an illusion. If we want valid patents, then there has to be some “good enough” threshold for enablement.
The focus in Amgen is a particularly tricky type of claim: genus claim with functional limitations. Here, the claim is directed to an isolated monoclonal antibody defined by its ability to bind with the protein PCSK9 and consequently block PCSK9 from binding to LDL-C.
An isolated monoclonal antibody [that] binds to [one of the residues of PCSK9] and … blocks binding of PCSK9 to LDRL.
US8829165 (US8859741 is also at issue). In its decision, the Federal Circuit found the claims too broad in comparison to the disclosure. “The functional limitations here are broad, the disclosed examples and guidance are narrow.” Thus, although the jury found the claims enabled, the appellate majority affirmed the district court’s post-verdict JMOL (notwithstanding the verdict). This is a biopharma case, but the decision here can also be seen largely as an attack on functional claim limitations across the spectrum of patent technology fields.
Now, Amgen has filed a strong petition for en banc rehearing arguing that the majority has improperly created a new stiffer test for genus claims with functional limitations.
Question 1: Whether the panel’s new enablement test for genus claims with functional limitations, which has no basis in §112’s text, conflicts with Supreme Court decisions, including Minerals Separation, Ltd. v. Hyde, 242 U.S. 261 (1916); Wood v. Underhill, 46 U.S. (5 How.) 1 (1846); and Mowry v. Whitney, 81 U.S. (14 Wall.) 620 (1872), and decisions of this Court and its predecessor, including AK Steel Corp. v. Sollac & Ugine, 344 F.3d 1234 (Fed. Cir. 2003), and In re Angstadt, 537 F.2d 498
As mentioned above, the question of enablement was given to the jury. Here, however, the Federal Circuit held that enablement is a question of law. The distinction is likely dispositive in this type of close case where the jury sided with the patentee. By treating enablement as a question of law, the Federal Circuit was able to review the issues de novo without impinging upon the reexamination clause of the 7th Amendment. The second question challenges this approach:
Question 2: Whether enablement is a question of fact, as the Supreme Court has held, see Battin v. Taggert, 58 U.S. (17 How.) 74 (1854); Wood v. Underhill, 46 U.S. (5 How.) 1 (1846), or a question of law, as this Court holds, Op.6.
The brief cites and discusses a really well researched and written article by Professors Karshtedt, Lemley, and Seymore titled The Death of the Genus Claim (forthcoming 2021). The article notes that today “it is no longer possible to have a valid genus claim. . . . [This] represents both bad law and bad policy.” Id. In its decision, the majority seemed to largely agree, but declined to expressly foreclose the possibility of genus claims.
This is a very important case for pharma and biotech patenting, but will also likely have an impact on the doctrine of enablement generally — especially its relationship to functional claim limitations since those are found in most patents. I expect a number of amicus briefs will be filed in the case over the next few weeks.
More to come.