Amgen Petitions for Certiorari to Reconsider Enablement of Genus Claims

As we reported earlier this year, Amgen filed a petition for rehearing en banc to the Federal Circuit, arguing that the panel in Amgen v. Sanofi improperly created a new and heightened test for enablement of genus claims with functional limitations.1 In its earlier decision, the Federal Circuit affirmed the district court’s judgment as a matter of law invalidating genus claims in U.S. Patent Nos. 8,829,165 and 8,859,741 that recite functional limitations covering Amgen’s cholesterol medication Repatha® as not enabled for the full scope of the claimed embodiments. Despite being joined by many amici arguing the significant ramifications of this decision for many biopharma companies, the Federal Circuit denied Amgen’s petition for rehearing en banc. Now, Amgen has filed a petition for certiorari to the Supreme Court reiterating the questions presented to the Federal Circuit.  In its petition for certiorari, Amgen posed the following questions:

[Question 1:] Whether enablement is “a question of fact to be determined by the jury,” ... or “a question of law that [the court] review[s] without deference,” ... as the Federal Circuit holds.

[Question 2:] 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 instead 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,’ ” ... 

Amgen argues that the Federal Circuit decision creates a new standard for enablement of genus claims.2  According to Amgen, the new test for enablement of genus claims reciting functional language is evaluated according to how much “time and effort” is required to make and test every embodiment so as “to reach the full scope of claimed embodiments,” thereby requiring the Applicant to identify every embodiment meeting the claimed function.  Specifically, an Applicant claiming a genus reciting functional language would have to identify and make all possible variations of the invention to satisfy the heightened enablement standard.  Amgen argues that the enablement requirement should not depend on the cumulative effort required to ferret out every conceivable implementation of the invention.

Amgen also argues that the Federal Circuit improperly invades the jury’s role, contrary to Supreme Court precedent.  Relying on the Supreme Court’s decision in Wood v. Underhill3, Amgen argues that the court has long held that whether a patent satisfies that “enablement” requirement is “a question of fact to be determined by the jury.”

The Federal Circuit’s continuing reliance on full scope enablement may have far-reaching consequences for patent protection for biologics and places onerous requirements on Applicants that seek genus claims - a common claiming strategy for biotechnology and pharmaceutical companies, particularly for antibodies. This heightened requirement could have chilling effects on the industry, requiring biotechnology companies to pursue claims with functional and/or structural limitations specific to a single compound. Such claims may not be adequate protection for antibodies and other biologics where structurally similar compounds may produce the same desired effects.  

This particular case started in 2014, and Amgen previously sought rehearing en banc and filed a petition for writ of certiorari with the Supreme Court when the first Federal Circuit panel to hear this case remanded to the district court for further analysis.  Both the request for rehearing en banc and the cert petition were denied at that time.  

Cynthia Rothschild, PhD is a partner in the Winston-Salem, NC office, Andrew T. Serafini, PhD is a partner in the Seattle, WA office, and Christopher Thomas is an associate in the Washington, DC office of Kilpatrick Townsend & Stockton, LLP.

The opinions expressed are those of the author(s) and do not necessarily reflect the views of the firm, its clients, or their respective affiliates. This article is for general information purposes and is not intended to be and should not be taken as legal advice.



Appellants’ Petition for Rehearing En Banc, Amgen Inc. v. Sanofi, 987 F.3d 1080 (Fed. Cir. 2021) (No. 20-1074).
Amgen Inc. v. Sanofi, 987 F.3d 1080 (Fed. Cir. 2021) (No. 20-1074), petition for cert. filed, (U.S., Nov. 18, 2021) (No. 21-757)
Wood v. Underhill, 46 U.S. 1, 4 (1846).
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