Pier D. DeRoo

Pier D. DeRoo is a Partner at Finnegan, Henderson, Farabow, Garrett & Dunner, LLP (Finnegan), specializing in strategic client counseling and patent litigation across various venues, including U.S. district courts, the U.S. Court of Appeals for the Federal Circuit, and the Patent Trial and Appeal Board (PTAB) of the USPTO.

His practice encompasses a broad range of technologies, with a particular emphasis on biotech and chemical clients. This includes monoclonal antibody pharmaceuticals, other biologics, small-molecule drugs, agriculture (e.g., crop protection and plant genetics), enzymes for food and biofuel production, and solid-state materials for renewable energy devices. Additionally, his experience extends to electrical arts, including collaboration software and internet security, as demonstrated by his representation of Google LLC in a patent dispute involving mobile device communication and push notification systems.

Mr. DeRoo frequently appears before the PTAB, having represented parties in more than 50 proceedings, including inter partes reviews (IPR), interference, reexamination, and ex parte prosecution appeals. He handles matters for both patent owners and petitioners in these proceedings. His notable engagements include representing Corteva Agriscience in district court litigation concerning transgenic plants, Eli Lilly in Federal Circuit appeals involving antibody patents, and Danisco in an IPR that resulted in a favorable institution decision followed by adverse judgment for the patent owner. In the tracked case, Google LLC v. Headwater Research LLC, where Google was a petitioner in an IPR, the related district court litigation concluded in February 2026, likely through a confidential settlement.

Admitted to practice in California, the District of Columbia, and Maryland, as well as before the U.S. Patent and Trademark Office, the U.S. Court of Appeals for the Federal Circuit, and the Supreme Court of the United States, Mr. DeRoo earned his J.D., with honors, from the University of Michigan Law School in 2011 and an A.B. in Chemistry, with honors, from Princeton University in 2006. He was recognized as a finalist for Managing Intellectual Property's Practitioner of the Year (PTAB) award in 2024.