HanByul Chang

HanByul Chang is a patent litigation attorney at Cooley, focusing her practice on a diverse array of intellectual property disputes across various technology sectors. Her experience encompasses patent infringement, Hatch-Waxman, and Biologics Price Competition and Innovation Act (BPCIA) cases, as well as trade secret litigation. Her technical background includes a PhD in Chemistry, which informs her work on matters involving pharmaceuticals, software, chemical technologies, and medical devices.

At Cooley, Ms. Chang handles both plaintiff and defendant-side work. While her tracked appearances show a plaintiff-side role in the significant Cytek Biosciences, Inc. v. Beckman Coulter, Inc. litigation, her firm profile highlights broader experience. She has been part of Cooley teams that secured notable outcomes for defendants, including a dismissal with prejudice for NETGEAR in patent litigation and successfully defeating an emergency motion for injunction for Samsung in BPCIA litigation.

A prominent case in her practice is Cytek Biosciences, Inc. v. Beckman Coulter, Inc., where she has represented Cytek as plaintiff, initially as an associate and later as counsel. This case involves patents related to flow cytometers and has also led to multiple Patent Trial and Appeal Board (PTAB) proceedings, including PGR2025-00088 and IPR2025-01319. The district court trial was set for August 2026.

Ms. Chang is active in Patent Office Litigation, indicating regular appearances in PTAB proceedings, in addition to federal district court litigation and appeals to the Federal Circuit. She is admitted to practice in California and before the U.S. District Courts for the Central, Eastern, Northern, and Southern Districts of California. She earned her J.D., cum laude, and a Ph.D. in Chemistry from Northwestern University in 2023, preceded by a B.S. in Chemistry from Gordon College in 2015.