Alex Siemers is an associate in the Washington, D.C. office of Latham & Watkins and a member of the firm’s Supreme Court & Appellate Practice.
Alex’s practice focuses on appellate litigation and dispositive motions in federal and state courts. He has written dozens of briefs and motions in a broad range of matters at all levels of the judiciary — ranging from briefs at the merits and certiorari stages before the United States Supreme Court to mid-trial briefing in district court. He also successfully argued an appeal before the Fourth Circuit, obtaining unanimous reversal on a question of first impression.
Alex’s experience includes a variety of substantive legal areas, including constitutional law, administrative law, antitrust, intellectual property, arbitration, class actions, and business disputes. He also maintains a robust pro bono practice, assisting in matters related to civil rights and religious liberty.
Before joining Latham, Alex clerked for Judge J. Harvie Wilkinson III of the United States Court of Appeals for the Fourth Circuit. He received his JD from Washington University School of Law, where he graduated summa cum laude and first in his class.
Experience
Alex’s representative experience includes:
Relentless, Inc. v. Department of Commerce, 603 U.S. 369 (2024) (companion case of Loper Bright Enterprises v. Raimondo): Obtained victory in case overturning Chevron deference
Ricketts v. Wake County Public School System, 125 F.4th 507 (4th Cir. 2025) (argued): Obtained unanimous victory on behalf of Davina Ricketts in reversing the dismissal of her Title VI and Equal Protection suit against her school district
Proofpoint, Inc. v. Vade USA, Inc., 2024 WL 4003096 (9th Cir. 2024): Obtained victory on behalf of Vade USA in a trade-secret case involving Seventh Amendment issues
Jazz Pharmaceuticals, Inc. v Becerra, 2024 WL 4625731 (D.D.C. 2024): Obtained victory on behalf of Avadel in APA case challenging the approval of Avadel’s once-nightly narcolepsy drug
North American Soccer League, LLC v. United States Soccer Federation, Inc., 2025 WL 1311115 (E.D.N.Y. 2025): Secured unanimous jury verdict for US Soccer rejecting antitrust conspiracy and monopolization claims
Jazz Pharmaceuticals, Inc v. Avadel CNS Pharmaceuticals, LLC, 136 F.4th 1075 (Fed. Cir. 2025): Obtained victory on behalf of Avadel in patent-infringement case invalidating overbroad portions of permanent injunction
United States v. Carpenter, 140 F.4th 733 (5th Cir. 2025): Obtained victory on behalf of Brian Carpenter in vacating his convictions after the erroneous mid-trial dismissal of a juror
Qualifications
Bar Qualification
District of Columbia
Education
JD, Washington University in St. Louis School of Law summa cum laude
M.Div., Princeton Theological Seminary
BA in Theology & Political Science, Colorado Christian University summa cum laude
A Latham team led by Chris Yates and Larry Buterman secured a unanimous jury verdict for the U.S. Soccer Federation in New York federal court, successfully defeating claims brought by North American Soccer League.
Latham litigators honored for obtaining a historic US Supreme Court decision siding with our client in Loper Bright Enterprises v. Raimondo and Relentless Inc. v. Department of Commerce, overruling the Chevron doctrine.
Pro bono client ran for student council in hopes of remedying its lack of diversity while in high school, but instead experienced harassment and cyberbullying.
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