As we have previously discussed, on February 11, 2021, the Federal Circuit decided Amgen Inc. et al. v. Sanofi, Aventisub LLC, et al. The Federal Circuit affirmed the district court’s grant of JMOL that Amgen’s Repatha® patents (U.S. Patent Nos. 8,829,165 and 8,859,741) were invalid for lack of enablement. The claims at issue cover a genus of monoclonal antibodies that bind to the proprotein convertase subtilisin/kexin type 9 (“PCSK9”) enzymes. This binding blocks PCSK9’s degradation of low-density lipoprotein (“LDL”) receptors, allowing the LDL receptors to continue regulating LDL cholesterol. The specification discloses amino acid sequences for twenty-six antibodies, including evolocumab (the antibody marketed as Repatha®). Before the district court granted Sanofi’s JMOL for lack of enablement, two separate juries had found that Sanofi failed to prove that the asserted claims were invalid for lack of written description and enablement.
The Federal Circuit affirmed the JMOL ruling, first citing its precedents holding that the enablement requirement under 35 U.S.C. § 112 is a question of law to be reviewed without deference. Then, the Federal Circuit concluded that practicing the full scope of the claims requires undue experimentation given the breath of the functional claim limitations, the guidance in the specification, and the unpredictability of the antibodies that would be produced. The Federal Circuit explained that it was not concluding “that the effort required to exhaust a genus is dispositive. It is appropriate, however, to look at the amount of effort needed to obtain embodiments outside the scope of the disclosed examples and guidance.”
Amgen petitioned for en banc review, which was denied on June 21, 2021, as we previously discussed. Subsequently, on November 18, 2021, Amgen filed a petition for a writ of certiorari asking the Supreme Court to overturn the Federal Circuit’s ruling. The petition presents two questions for review:
- whether enablement is “a question of fact to be determined by the jury . . . as [the Supreme] Court has held,” or whether it is “a question of law that the court reviews without deference . . . as the Federal Circuit holds.”
- whether enablement is governed by the statutory requirement that the specification teach those skilled in the art “to make and use” the claimed invention, or whether it must enable those skilled in the art “to reach the full scope of claimed embodiments” without undue experimentation – i.e. “to cumulatively identify and make all or nearly all embodiments of the invention without substantial time and effort.”
For the first issue, Amgen points to Supreme Court decisions holding that “enablement” is “a question of fact to be determined by the jury.” Amgen notes that Federal Circuit cases that have held the opposite. Interestingly, in a separate opinion on the denial of the petition for Federal Circuit en banc review, Judges Lourie, Post, and Hughes had stated, “[o]ne can reasonably ask, as Amgen does, why enablement is a question of law.” However, these judges went on to say that they saw no reason to revisit this issue because its precedent is “long in the tooth.” Amgen proceeds to point out that the Supreme Court’s precedent is even older than the Federal Circuit, and either way the Supreme Court’s precedent is binding on the Federal Circuit. Finally, Amgen argues that the Federal Circuit’s decision that enablement is a question of law invades the role of the jury.
On the second issue, Amgen argues that the Federal Circuit created a new “hurdle” to the enablement requirement, especially for genus claims. Amgen emphasizes that the Federal Circuit’s requirement that the specification teach the skilled artisan “to reach the full scope of claimed embodiments” means that the patent must teach how to make all or nearly all the embodiments of the invention without “substantial time or effort.” Amgen argues that it is impossible to specify every conceivable implementation of the invention in a patent. It believes this new “hurdle” will be particularly harmful to the biotech and pharmaceutical innovations, since the Federal Circuit may tend to invalidate claims based merely on the size of the genus they encompass.
Amgen claims that its patents include a step-by-step “roadmap,” which employs methods routine in the art, for making additional antibodies to PCSK9. Amgen claims that the Federal Circuit did not identify any actual embodiment that could not be made by following this “roadmap,” and thus improperly held the claims invalid.
It will be interesting to see whether the Court will grant Amgen’s petition for certiorari to examine whether the Federal Circuit has strayed from prior Supreme Court decisions holding that enablement is a question of fact to be decided by the jury. The Supreme Court has shown a willingness to overturn longstanding Federal Circuit precedent where it perceives a conflict with the Court’s prior holdings. This is a decision to watch, as whether enablement is a question of law to be decided by a judge or a question of fact to be decided by a jury will affect both challengers’ and a patentees’ litigation strategies. If enablement questions must be decided by a jury, they may, in practice, become a less powerful means of challenging arguably overbroad patent claims due to the expense of reaching a jury determination.
 Wood v. Underhill, 46 U.S. (5 How.) 1, 4 (1846).
 See Raytheon Co. v. Roper Corp., 724 F.2d 951, 960 n.6 (Fed. Cir. 1983).
 Amgen Inc. v. Sanofi, Aventisub LLC, 850 F. App’x 794 (Fed. Cir. 2021).
 See MedImmune, Inc. v. Genentech, Inc., 549 U.S. 118 (2007); see also TC Heartland LLC v. Kraft Foods Grp. Brands LLC, 137 S. Ct. 1514 (2017).