Simeon primarily focuses his practice on patent litigation in federal courts and post-grant proceedings before the patent office. Simeon has argued matters in federal district court and before the Court of Appeals for the Federal Circuit and has represented clients in bench and jury trials as well as arbitrations in federal courts. He has represented clients across a wide range of industries, primarily dealing with medical devices, pharmaceuticals, biotechnology, and drilling and oilfield services, while also working with computer hardware and software, consumer products, and video games.

Simeon has additional experience dealing with patent-related antitrust issues, trademark litigation and counseling, and trade secrets, as well as general intellectual property due diligence and counseling regarding both domestic and international intellectual property matters.