Deric X. Geng

Deric X. Geng is a patent litigation attorney at Wilmer Cutler Pickering Hale & Dorr, where he focuses on patent prosecution and litigation, particularly in the life sciences sector. His practice encompasses US and foreign patent prosecution, due diligence, prior art and patentability searches, freedom to operate analysis, inter partes review (IPR), and patent litigation. He frequently handles Hatch-Waxman and other patent litigations for leading pharmaceutical companies, and his experience extends to chemical, biotechnology, and energy industries.

Based on tracked appearances, Mr. Geng has primarily worked on the plaintiff side, with one recorded instance as lead counsel for the plaintiff. This aligns with his practice of representing pharmaceutical companies in patent enforcement actions.

A notable case in his practice is Merck KGaA v. Hopewell Pharma Ventures, Inc. (D. Del., Civ. No. 22-1365), a Hatch-Waxman litigation concerning Merck's multiple sclerosis drug Mavenclad® (cladribine). While Mr. Geng served as lead counsel for the plaintiff, Merck KGaA, the defendants successfully challenged Merck's asserted patent claims through inter partes reviews (IPR2023-00480 and IPR2023-00481). The Patent Trial and Appeal Board's decision invalidating the asserted claims was affirmed by the Federal Circuit on October 30, 2025. This case highlights his involvement in complex pharmaceutical patent disputes, including those with significant PTAB and Federal Circuit appellate components. His profile specifically lists inter partes review as a focus area.

Mr. Geng holds a J.D. from Suffolk University Law School (2013, summa cum laude), a Ph.D. in Chemistry from State University of New York at Stony Brook (2002), and a B.S. in Chemistry from Peking University (1997). He is admitted to practice in Massachusetts.