Doreen Trujillo is a patent partner and represents her clients in numerous facets of patent law, including prosecution and counseling, opinion preparation, licensing, due diligence, and litigation. She has prosecuted patent applications in the United States and abroad, and has experience handling patent interferences, including as lead counsel, reissues, and ex parte reexaminations. Doreen also has experience briefing and arguing ex parte appeals before the Patent Trial and Appeal Board of the U.S. Patent & Trademark Office, and briefing and arguing appeals before the U.S. Court of Appeals for the Federal Circuit. Doreen has extensive experience in obtaining patent term adjustment for patents she prosecuted. She also has experience seeking patent term extension.

Doreen has a strong background in the life sciences and biotechnology, with a focus on immunology. Before going to law school, Doreen worked for several years as a research assistant at The University of Texas Health Science Center in Houston in a monoclonal antibody laboratory. Her work there focused on tissue culture, hybridoma production, animal testing, and immunoassay development.

Before joining VLP, Doreen was a partner/shareholder at several national general practice law firms in the Philadelphia area. Before that, Doreen worked at two boutique intellectual property firms, and served as the vice chair of the Prosecution Practice Group at one of those firms.

Doreen was recently included in the 2024 edition of The Best Lawyers in America® for Patent Law.


  • J. D., University of Houston Law Center, 1990
  • B.S., Juniata College, 1981, cum laude

Doreen has prosecuted several patents which cover FDA-approved products. She understands the importance of obtaining robust patents.

  • “Federal Circuit Rehearing Denial in Forum Selection Ruling Is Good News for Patent Owners,” IP Litigator, July/August, 2022.
    • Panel Member for “Incentivizing Pharma Innovations in the Biden Administration,” Life Sciences Masters Program, IP Watchdog, 2022.