Sailesh Patel

Sailesh K. Patel is a highly experienced patent litigator and a co-leader of the Intellectual Property Litigation practice at ArentFox Schiff. He specializes in complex patent disputes, with a particular focus on Hatch-Waxman and biosimilars litigation, leveraging his background in chemistry and bioengineering. Patel's practice extends to diverse technology sectors, including life sciences, automotive, software, semiconductors, clean tech, and food/beverage.

Patel maintains a balanced practice, representing both innovator and generic/biosimilar pharmaceutical companies. While his tracked appearances include plaintiff-side representation for biosimilar developer Fresenius Kabi SwissBioSim GmbH, his firm's work and his professional profile indicate experience advising clients on both sides of Hatch-Waxman Paragraph IV and biosimilars design strategies, as well as asserting patents for branded companies.

He is a seasoned trial attorney, having first-chaired more than 10 trials and appeals. Patel was involved in Fresenius Kabi SwissBioSim GmbH v. Regeneron Pharmaceuticals, Inc., a matter concerning IPRs challenging Regeneron's EYLEA® patents, which ultimately settled after the PTAB denied institution of the IPR petitions. His experience also includes a notable instance where the Federal Circuit reversed a PTAB IPR claim construction decision in Microsoft Corp. v. Proxyconn Inc. Patel is also active in post-grant proceedings, serving as lead counsel on numerous Inter Partes Reviews (IPRs).

Patel earned his J.D. from Boston College Law School in 1999 and a B.S. from Northwestern University in 1996. He is admitted to the Illinois Bar, the U.S. Court of Appeals for the Federal Circuit, the U.S. District Court for the Northern District of Illinois (Trial Bar), the U.S. District Court for the Eastern District of Michigan, and is registered with the U.S. Patent and Trademark Office.