Barclay Damon
Barclay Damon


Denis Sullivan


p: 315.425.2868

f: 315.703.6252

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Syracuse Office

Barclay Damon Tower
125 East Jefferson Street
Syracuse, New York 13202

Denis is Barclay Damon’s Intellectual Property Practice Group leader and the co-team leader of the technology, medical devices, communications and networking technology, and emerging technologies teams. A nationally recognized intellectual property lawyer and registered patent attorney, Denis handles patent infringement disputes in federal district court and at the International Trade Commission, patent office proceedings such as inter partes reviews and reexaminations, and the preparation of patent applications.

His experience as both a patent litigator and patent prosecutor enables Denis to successfully challenge and defend patents under the America Invents Act before the US Patent and Trademark Office. Denis regularly serves as lead counsel in IPRs of patents involved in district court litigation.

His ability to provide clients with high-value intellectual property counsel is enhanced by his strong engineering background, which includes several years working as a licensed professional engineer. This technical experience enables Denis to handle patent matters across a wide variety of technologies and industries, including health care, telecommunications, semi-conductor manufacturing, and oil and gas.

Representative Experience

  • Served as lead counsel in over 30 IPRs of patents involved in district court litigation.
  • Served as lead counsel in federal circuit appeals of IPR decisions.
  • Served as lead counsel in reexaminations of several patents involved in district court litigation.
  • Served as lead counsel in a patent infringement action involving software patents for electronic shareholder communications.
  • Served as trial counsel in an ITC proceeding involving patents for coaxial-cable connectors. Obtained two general-exclusion orders and one limited-exclusion order.
  • Served as trial counsel in a declaratory judgment action involving patents for chemical de-icers.
  • Served as lead patent counsel in a district court appeal of the USPTO interference proceeding. Obtained a summary judgment reversing the patent office to preserve the validity of the patent.
  • Prepares and prosecute patent applications and appeals for domestic and foreign clients, including Fortune 100 clients.
  • Provides counseling and legal opinions concerning the validity and infringement of patents.

Practice Areas


  • New York Law School, J.D., summa cum laude (Class Rank: 1), New York Law School Law Review, 2002
  • Manhattan College, B.S., summa cum laude (Class Rank: 1), General Excellence Award in Electrical Engineering, 1993

Admitted To Practice

  • New York, 2003
  • U.S. Patent and Trademark Office
  • U.S. District Court, Northern District of New York
  • U.S. District Court, Southern District of New York
  • U.S. District Court, Eastern District of New York
  • U.S. District Court, Western District of New York
  • U.S. Court of Appeals, Federal Circuit

Memberships & Affiliations

  • New York State Bar Association
  • American Intellectual Property Law Association
  • Intellectual Property and Innovation American Inn of Court
  • New York State Licensed Professional Engineer

Civic Activities

  • Youth Sports Coach

Speaking & Publications

  • Practicing Law Institute’s 11th Annual Patent Law Institute, “The Patent Trial and Appeal Board Turns Five”
  • IP Counsel Exchange, “PTAB Litigation Crash Course: A Litigator’s Guide to Obtaining Successful Results at the PTAB”
  • Rochester Intellectual Property Law Association, “Escaping From Wonderland: An Analysis of Decisions Where Patent Claims Have Survived Section 101 Challenges Under Alice Corp. v. CLS Bank
  • Practicing Law Institute’s Ninth Annual Patent Law Institute, "Inter Partes Review and Post-Grant Review: Interplay of PTAB/District Court Litigation"
  • Law360, “Strategies for Avoiding Institution of an IPR”

Prior Experience

  • Marjama Muldoon Blasiak & Sullivan LLP, Partner
  • Kirkland & Ellis LLP, Associate
  • Port Authority of New York and New Jersey, Electrical Engineer and Project Manager

Patent Experience