Caryn Borg-Breen

Caryn Borg-Breen, Ph.D.


Caryn Borg-Breen is an accomplished first-chair patent litigator with more than 20 years of experience in patent litigation, client counseling, and prosecution. She combines the technical insight of a Ph.D. chemist with the strategic focus and competitive strengths of a trial attorney.

Caryn has represented both plaintiffs and defendants in patent litigation. A significant percentage of her practice over the last 15 years has been in Hatch-Waxman litigation, primarily representing brand pharmaceutical companies against generic ANDA filers in matters pending in the District of Delaware and District of New Jersey. In addition, she has argued numerous matters before the Federal Circuit and PTAB. She also has significant experience drafting and negotiating patent license agreements, covenants not to sue, and settlement agreements.


Representative Matters

  • Lead trial lawyer representing Horizon Therapeutics in multiple patent litigations arising under Hatch-Waxman concerning Horizon’s RAVICTI oral glyceryl phenylbutyrate product. One case is currently pending in the District of New Jersey. Prior cases against earlier generic filers were settled under favorable terms.
  • Co-lead trial lawyer representing Clarus Therapeutics in patent litigation with competitor Lipocine, Inc. concerning Clarus’s JATENZO oral testosterone undecanoate product. Won on summary judgment before district court (D.N.J.) obtaining a finding that all claims of competitor’s asserted patents were invalid for lack of written description.
  • Lead trial lawyer representing Horizon Therapeutics in multiple patent litigations arising under Hatch-Waxman concerning Horizon’s PENNSAID topical diclofenac product. Won before district court (D.N.J.) obtaining finding of patent infringement and patent validity and injunction of generic approval until patent expiration. Won on appeal before the Court of Appeals for the Federal Circuit. Cases against other generic filers were settled under favorable terms.

Professional Highlights

Professional Activities

Chicago Women in IP

Coalition of Women’s Initiatives in Law

Recognition & Accomplishments

Managing IP, Americas: Award Shortlist – Illinois Practitioner of the Year in Litigation, 2021, 2022; “IP Star,” 2018-2024; "Top 250 Women in IP," 2022

IAM Patent 1000: The World's Leading Patent Professionals, 2023, 2024

LMG Life Sciences America: Finalist – General Patent Litigator of the Year in Midwest, 2020; Shortlist – Patent Strategy Attorney of the Year in Midwest, 2023; Life Sciences Star, 2018-2021; General Patent Litigation, Hatch-Waxman Patent Litigation, 2022, 2023 

The Best Lawyers in America: Litigation – Patent, 2020-2024 (Philadelphia)

Speaking Engagements

Panelist, “Venue War Room: Knowing How, When, And Where To Plan Your Attack Based On Current Trends In MDL With Joint Defense Groups,” ACI 8th Annual Paragraph IV Disputes Master Symposium, September 2022

Panelist, “How to Grow Your Law Firm During and After the Pandemic,” Chicago Bar Association Young Lawyers Society IP Law, April 2021

Panelist, Chicago Daily Law Bulletin and Chicago Lawyer Magazine’s Women in Law Conference, Morning Lineup Live, Chicago, IL, December 2018


“FDA Struggles To Foster an Affordable Biosimilar Insulin,” Law360, October 2019

 “Garage Door Openers, Printer Toner Cartridges, and the New Age of the DMCA,” N.U. Law Review, 2006

“Synthesis and investigation of the redox properties of platinum-linked metallophosphine clusters: Model systems for extended one-dimensional cluster arrays,” Ph.D. Thesis 2000

Synthesis of the Bifunctional Phosphinidene Cluster, Fe3(CO)93-PH)2 , and a Systematic Study of the Reactivity of the Cluster-Bound P−H Functional Group,” J. Am. Chem. Soc. 2000



Northwestern University School of Law (J.D., cum laude, 2006)

University of North Carolina at Chapel Hill (Ph.D., Chemistry, 2000)

The College of William and Mary (B.S. magna cum laude, 1994)




U.S. Supreme Court

U.S. Court of Appeals for the Federal Circuit

U.S. District Court for the Northern District of Illinois

United States Patent and Trademark Office