Xiaoxiang (Sean) Liu, Ph.D.


Sean Liu, a named inventor on more than 10 issued U.S. patents, delivers value to clients through his understanding of complicated technical and legal issues in patenting chemicals and pharmaceuticals.

Xiaoxiang (Sean) Liu, Ph.D., a Nixon Vanderhye Shareholder, focuses his practice on patent portfolio management for companies in the fields of biotechnology, chemicals, pharmaceuticals, and food and beverages. Sean assists clients in procuring U.S. and foreign patents and conducting due diligence analysis. He also advises clients on issues relating to freedom-to-operate, non-infringement, patentability, and invalidity. Sean is experienced in contested cases, including patent office litigations, ITC 337 investigations, and district court litigations involving Abbreviated New Drug Applications (ANDAs) under the Hatch-Waxman Act.

Sean’s technical skills include organic synthesis, organometallic chemistry, combinatory chemistry, polymer chemistry, medicinal chemistry, lead identification and optimization, polymorphs, pharmaceutical formulations, pharmacokinetics, biomarkers related to personalized medicines, and dosing regimens. He is the co-author of more than 16 scientific papers in peer-reviewed journals.

A veteran of the life science industry, Sean worked as a medicinal chemist in Wyeth (now Pfizer) and Schering-Plough (now Merck) for more than eight years before pursuing a career in law. During this period, he designed and synthesized therapeutic agents for the treatment of various diseases, such as Alzheimer’s disease, cancer, cardiovascular disease and infectious disease. Sean received the “President’s Award for Excellence in Drug Discovery” from Schering-Plough because of his contribution to the company’s Alzheimer’s disease program.

Sean obtained his Ph.D. in organic chemistry from University of Wisconsin-Milwaukee. His doctoral thesis focused on the total synthesis of anti-malarial indole alkaloids. As a post-doctoral associate at Yale University, he discovered new palladium catalyzed cross-coupling reactions.

Sean is fluent in Mandarin Chinese.

  • District of Columbia
  • New Jersey
  • New York
  • U.S. Patent and Trademark Office
  • J.D., magna cum laude, Seton Hall University School of Law, 2011
  • post-doctoral associate, Yale University, 2002-2003
  • Ph.D. in Organic Chemistry, University of Wisconsin-Milwaukee, 2002
  • B.S., Xiangtan University, 1996

Get To Know Sean

Where can you be found outside the office?

Hiking with my family.

What would your perfect day include?

Family time at a beach in Hawaii.

What inspires you?

The many wonders of nature.