Federal Circuit Follows Through on Amgen Enablement Analysis in Baxalta Inc. v. Genentech

Following the Supreme Court’s Amgen decision last summer,[1] the Federal Circuit has affirmed the invalidity of yet another functionally-defined antibody patent for lack of enablement in Baxalta Inc. v. Genentech, Inc., 81 F.4th 1362 (Fed. Cir. 2023) (mem.).

Baxalta owns U.S. Patent No. 7,033,590 (’590 patent), directed to antibodies that bind a particular enzyme to increase procoagulant activity as a form of hemophilia treatment. The ’590 patent disclosed 11 antibody sequences having the claimed properties and explained how a skilled artisan could use known hybridoma bioengineering techniques to obtain additional antibodies falling within the scope of the claims.

The Federal Circuit characterized the facts in Baxalta as “materially indistinguishable from those in Amgen” because the patents at issue in both cases potentially encompassed millions of antibodies that bind to a particular target and exert a particular functional effect. Id. at 1366. In addition, the patents in both cases provided limited exemplary antibodies, coupled with a roadmap for a skilled artisan to run experiments in search of additional antibodies falling within the functionally-defined claim scope. The Court noted that, as in Amgen, nothing in the ’590 patent explained why the disclosed antibody sequences resulted in increased procoagulant activity while other screened antibodies did not, or otherwise allowed for extrapolation to identify additional antibodies falling within the claims.

The Court also rejected Baxalta’s analogy to In re Wands,[2] which likewise disclosed hybridoma methods for producing antibodies that bind a target and claimed methods of using those antibodies for hepatitis detection. While agreeing that Amgen did not disturb Wands’ “undue experimentation” standard, the Court relied on its previous factual distinction between the Wands and Amgen cases,[3] indicating that functionally defined claims similar to those in Amgen will face a similar fate under 35 USC § 112.

In light of this opinion, patent applicants should exercise care when claiming classes of compounds or biologics based on their function. Patentees may also wish to reassess their portfolios or those of third parties as this ruling could further affect the strength of functionally-claimed assets.

Endnotes

[1] Amgen Inc. v. Sanofi, 598 U.S. 594 (2023).

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

[3] Citing Amgen Inc. v. Sanofi, Aventisub LLC, 987 F.3d 1080, 1085-86 (Fed. Cir. 2021).