On April 18, 2022, the Supreme Court invited the Solicitor General to file a brief expressing the views of the United States in the Amgen, Inc. v. Sanofi, Inc. case, which involves important questions of enablement for genus claims. We have previously covered the Federal Circuit’s decision, Amgen’s petition for a writ of certiorari, and the multiple amicus curiae briefs submitted in this case. Additionally, on March 14, 2022, Sanofi filed its Opposition to Amgen’s cert petition, and on March 22, 2022, Amgen filed its Reply Brief. The Supreme Court’s Call for the Views of the Solicitor General (“CVSG”) signals the Court’s interest in this case. This post provides a summary of Sanofi and Amgen’s latest briefing. We will continue to provide updates as this case evolves.

The introduction of Sanofi’s Opposition is direct, arguing that Amgen “attempt[ed] to corner the market on PCSK9 inhibitors—and after Respondents developed Praluent—Amgen obtained additional patents that broadly claim all antibodies that bind to certain amino acids on PCSK9 and clock its binding to receptors.” Sanofi argues that the Federal Circuit’s decision “rightly rejected this gambit, holding that Amgen’s broad functional claims are not enabled and thereby invalid under 35 U.S.C. § 112.” It further tried to persuade the Court that the decision does not need to be reviewed, as “in its unanimous decision, the [Federal Circuit] panel merely applied well-established law to the undisputed relevant facts and determined that Amgen’s broad functional claims require undue experimentation and thus are not enabled by the particular specification.”

In response to Amgen’s first argument that the Federal Circuit treated the enablement issue as a question of law while the Supreme Court has treated it as a question of fact, Sanofi alleges that the Supreme Court has consistently held that patent validity issues like enablement are questions of law involving subsidiary findings of fact. Sanofi cites Supreme Court cases framing the issue of patent validity as a question of law, and cites Federal Circuit cases that have followed suit. It argues that Amgen “cites a handful of this Court’s decision predating the Civil War.” Sanofi discusses parts of Amgen’s cited cases to argue that these cases do not actually contradict the Federal Circuit’s decision. While Sanofi acknowledges that some of the cases Amgen cites included factual issues for the jury, it argues the issues related to the capabilities of the person skilled in the art. Sanofi thus argues that there is no reason for the Supreme Court to hear this case because it is consistent with precedent. Sanofi even asserts that “Amgen also vastly overstates the importance of this issue,” which is interesting given the multiple amicus briefs submitted encouraging the Supreme Court to take up the case.

As to Amgen’s second argument that the Federal Circuit’s decision created a special test applicable to functional genus claims, Sanofi states this is simply not true; the Federal Circuit repeatedly disclaimed any bright-line rule, and its holding was only a result of applying the same factors that the Federal Circuit has used in the past. Sanofi insists that Amgen’s second argument “is nothing more than a request for factbound error correction dressed up as a supposed legal dispute.” It notes that the Federal Circuit repeatedly stated its decision was not a bright-line rule, and that the Federal Circuit decided Amgen’s claims required undue experimentation after considering the Wands factors in this specific case.[1] Sanofi argues that Amgen neither challenged the use of the Wands factors nor the breadth of its claims. It contends that the Federal Circuit created no new test for enablement, but the claims were not enabled to allow one of ordinary skill to make and use the full scope of the invention.

Amgen’s Reply Brief is consistent with the arguments made in its petition. First, Amgen states that “Sanofi-Regeneron cannot dispute that this Court has repeatedly declared that enablement is a ‘question of fact’ for ‘the jury.’”[2] Amgen cites cases concluding that enablement is a question of fact for the jury, and argues that the determination of whether a jury or a judge should decide if a patent is enabled is extremely important for patent infringement cases. Second, Amgen argues that the Federal Circuit’s holding that the specification must enable skilled artisans “to reach the full scope of claimed embodiments” without “substantial time and effort” was unnecessary, as the evidence shows that the skilled artisan could make the antibodies that Amgen claimed every time by following the patent’s specification. Amgen argues that this “full scope” decision is equivalent to imposing a numerosity or exhaustion requirement.  It argues that this “rewriting” of § 112 was unnecessary, as the Federal Circuit could have required, as it has before, that the challengers provide concrete evidence that a substantial number of embodiments cannot be made by following what the patent teaches. Amgen argues that the Supreme Court has never suggested that patents are invalid when skilled artisans can easily make embodiments within the claims, simply because ‘substantial time and effort’ is needed to make all embodiments. It argues the importance of the Supreme Court granting certiorari, as the Federal Circuit’s decision will raise the bar for enablement of genus claims far too high. Finally, Amgen argues that this case is an ideal vehicle for Supreme Court review: “Two different juries heard the evidence and found Amgen’s patents enabled—yet the Federal Circuit reaches a contrary result. Who decides enablement was clearly outcome-dispositive.”

[1] See In re Wands, 858 F.2d 731 (Fed. Cir. 1988).

[2] Wood v. Underhill, 46 U.S. (5 How.) 1, 4 (1846).