Solicitor General Urges Supreme Court to Deny Cert in Amgen Antibody Patenting CaseSeptember 26, 2022

In an amicus brief for the United States Government released September 21, 2022, the Solicitor General advises the Supreme Court to deny Amgen Inc.’s petition for a writ of certiorari in the Amgen v. Sanofi case. If the Supreme Court follows the Government’s suggestion, it could mean a swift end for the controversial antibody patenting case.

Procedural History

Amgen first sued Sanofi in 2014, alleging Sanofi’s marketing of their cholesterol drug Praluent™ infringed two of Amgen’s patents directed to anti-PCSK9 antibodies. The claims at issue (claims 19 and 29 of U.S. Patent No. 8,829,165 and claim 7 of U.S. Patent No. 8,859,741) are so-called “functional” antibody claims. Rather than claim the structure of a specific antibody, the claims cover any antibody that performs a recited function, thus providing the patentee with broader coverage. In this case, the Amgen claims recite isolated monoclonal antibodies that bind to specific residues on proprotein convertase subtilisin/kexin type 9 (PCSK9) and block interaction with LDL receptors.

Sanofi responded to the suit by arguing the claims were invalid for lack of written description and enablement, alleging the claims covered a large genus of antibodies without providing sufficient examples or a structure-function correlation. Amgen argued that the claims were valid because the specification disclosed a newly characterized epitope that disrupts PCSK9 signaling, entitling Amgen to a broader claim scope. At the close of trial, the jury determined that the claims were not invalid for lack of enablement.

On appeal, the Federal Circuit reversed and remanded for a new trial, holding that the district court had erred in not allowing the jury to hear Sanofi’s post-priority date evidence related to the structural differences of Praluent™ and the amount of experimentation needed to identify and develop Praulent™. Furthermore, the Federal Circuit rejected the idea of an “antibody exception” to the written description requirement and held that identifying an epitope is not, by itself, enough to satisfy the written description requirement. On remand, a jury once again upheld Amgen’s claims as valid, but the court set aside the jury’s decision and granted Sanofi’s motion for a judgment as a matter of law (JMOL). In doing so, the court held the claims invalid for lack of enablement, stating that enablement is a legal question and that there was no question that undue experimentation would be required to make and test all antibodies to determine if they bind as claimed in Amgen’s patent. The Federal Circuit affirmed.

Amgen’s 2021 Petition for Writ of Certiorari

Following the Federal Circuit’s decision, Amgen filed a petition for a writ of certiorari to the U.S. Supreme Court. In their petition, Amgen posed two questions: 1) Whether the court of appeals gave insufficient weight to the jury’s verdict in affirming the district court’s grant of judgment as a matter of law based on lack of enablement and 2) Whether the court of appeals correctly determined that the challenged claims are not adequately enabled. Amgen’s petition argued that functionally claimed genus claims are effectively being held a heightened enablement standard—one that would require an applicant to identify and make all possible variations of the invention to satisfy.

The Government’s amicus brief summarily rejects Amgen’s arguments, alleging they lack merit and aren’t worthy of further review by the Supreme Court. Regarding the first question of whether the court of appeals erred by treating enablement as a question of law, the brief states that the enablement inquiry includes both legal and factual components. The brief brushes aside Amgen’s arguments and states, “In short, petitioners have failed to show that their semantic disagreement with the court of appeals carries any practical significance.” Gov’t CVSG Brief in Amgen Inc. v. Sanofi, 21-757 (Supreme Court 2022). Regarding the second question of whether the lower court erred in finding the claims invalid for lack of enablement, the brief is equally dismissive. Responding to Amgen’s argument that functional genus claims are held to a higher enablement standard, the brief states, “Because a patent’s disclosure must be commensurate with the scope of its claims, broad claims naturally require more extensive enablement.” Id. For both issues, the brief suggests the case is a “poor vehicle” for considering these questions due to unresolved disputes about the scope of the record and recommends the Court deny the petition.

The ultimate implications remain to be seen. Historically, the Solicitor General’s amicus brief has been a strong predictor for the outcome of certiorari. However, the conservative majority Court has lately been straying from the suggestions of a liberal administration, so it is anyone’s guess what will happen next in the Amgen saga.

Melissa Mitchell is an intellectual property attorney in the MVS Biotechnology and Chemical Practice Group. To learn more, visit our MVS website, or contact Melissa directly via email.

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