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Paul A. Ainsworth

Paul A. Ainsworth

Paul A. Ainsworth, a director in Sterne Kessler's Trial & Appellate Practice Group, is an experienced intellectual property trial attorney with a practice focused on patent and trade secret disputes in federal district courts, at the U.S. International Trade Commission (ITC), and before the United States Court of Appeals for the Federal Circuit. Paul also regularly represents clients in proceedings before the Patent Trial and Appeal Board (PTAB). Paul's clients include leading companies in the pharmaceutical, medical devices, chemical manufacturing, consumer products, electronics, and e-commerce industries.

Paul is particularly well-known for his work in the firm’s award-winning Hatch-Waxman litigation practice. From pre-litigation strategy through trial, appeal, and/or settlement, he has led teams on more than twenty patent cases for both innovator and generic drug clients. Paul leverages his deep understanding of the IP, regulatory, and business dynamics unique to the pharmaceutical industry to assist his clients in achieving their business objectives.

Paul is also a leader in the firm’s high-profile ITC practice. Section 337 investigations have a well-earned reputation for being fast-paced, high stakes, and unforgiving. Paul has skillfully and successfully represented complainants and respondents in investigations involving their most important product markets.

Paul also has significant experience representing clients, particularly pharmaceutical, biotech, and software companies, in trade secret matters. With uncertainty growing around the ability of U.S. patent law to protect IP portfolios, clients turn to Paul for planning and executing effective trade secret strategies to safeguard what is often their most valuable asset.

Paul is a contributing author of Patent Office Litigation, Second Edition, published in 2017 by Thomson Reuters Westlaw. The book provides a fresh and comprehensive exploration of patent office litigation proceedings, including how the proceedings interact with other aspects of patent procurement and enforcement, while delivering practical analysis and advice.

Paul began his legal career as a law clerk for the Honorable Sue L. Robinson, United States District Judge, District of Delaware. In addition to his patent litigation practice, he has also represented leading civil rights organizations on state and federal civil rights issues. In 2011, the National LGBT Bar Association named Paul as one of the “Best LGBT Lawyers Under 40” in recognition of both his accomplishments as an IP litigator and his contributions to the advancement of LGBT civil rights.

When not in the courtroom, Paul is most likely to be found hiking in the Allegheny Mountains with his dog, Rugby.


  • Super Lawyers, "Super Lawyer - Washington, DC" (2017)

  • Super Lawyers, "Rising Star - Washington, DC" (2014)

Representative Matters

Hatch-Waxman and Biosimilar Matters
  • Genentech, Inc. et al. v. Sandoz, Inc. et al (D.N.J.) (counsel for Sandoz in litigation concerning rituximab)
  • Braintree Laboratories v. Lannett  Co. (D. Del.) (lead counsel for Lannett Co. in litigation concerning a bowel prep kit—Suprep®.)
  • Adapt Pharma Ops.  v. Teva Pharmaceuticals USA (D.N.J.) (counsel for Teva in litigation concerning a treatment for opioid overdose—Narcan®)
  • Insys Therapeutics v. Teva Pharmaceuticals USA (D. Del.) (counsel for Teva in litigation concerning a pain management treatment--Subsys®)
  • AstraZeneca AB et al. v. Kremers Urban Pharmaceuticals Inc., (D.N.J.) (lead counsel for Kremers Urban in litigation concerning a treatment for gastroesophageal reflux disease--Nexium®)
  • Salix Pharmaceuticals, Inc. v. Novel Laboratories, Inc., (D. Del.) (counsel for Novel Laboratories in litigation concerning a treatment for ulcerative colitis—Apriso®)
  • IntelGenx Corp. v. Wockhardt Bio, AG, (D.N.J.) (counsel for IntelGenx in litigation concerning a treatment for major depression—Forfivo®)
  • Helsinn Healthcare S.A. v. Aurobindo Pharma Ltd., (D. Del.) (counsel for Aurobindo in litigation concerning an anti-nausea medication—Aloxi ®)
  • Alcon Pharmaceuticals Ltd. v. Apotex, Inc., (D. Del.) (counsel for Apotex in litigation concerning a treatment for bacterial conjunctivitis--Vigamox®)
  • Galderma Laboratories Inc. et al v. Amneal Pharmaceuticals, LLC et al., (D. Del.) (counsel for Amneal in litigation concerning a treatment for rosacea--Oracea®)
  • Medeva Pharma Suisse A.G. et al v. Roxane Laboratories, Inc., (D.N.J.); Medeva Pharma Suisse A.G. et al. v. Par Pharmaceuticals et al. (D.N.J.) (counsel for patentee and licensee in a multi-case litigation concerning a treatment for ulcerative colitis–Asacol®)
  • Shire LLC v. Watson Laboratories, Inc., (S.D.N.Y)(S.D. Fla.) (counsel for patentee litigation concerning a treatment for attention deficit hyperactivity disorder – Adderall XR®)
  • In re Certain Road Milling Machines and Components Thereof, ITC Investigation No. 337-TA-1067 (counsel for Complainant Wirtgen American in an ITC investigation pertaining to road construction equipment)
  • In re Lithium Silicate Materials and Products Containing the Same, ITC Investigation No. 337-TA-911 (counsel for Complainant Ivoclar Vivadent AG in an ITC investigation pertaining to lithium silicate-based dental prostheses)
  • In re Certain Motorized Self-Balancing Vehicles, ITC Investigation No. 337-TA-1000 (counsel for Respondent Powerboard in an ITC investigation pertaining to personal transport vehicles)
  • In re Certain Overflow and Drain Assemblies for Bathtubs and Components Thereof, ITC Investigation No. 337-TA-993 (counsel for Complainant WCM Industries in an ITC investigation pertaining to screwless bathtub drain assemblies)
  • In re Certain Video Game Machines and Related Three-Dimensional Pointing Devices, ITC Investigation No 337-TA-658 (counsel for respondent Nintendo in an ITC investigation concerning television interactive program guide and 3D pointing device technologies)
  • Julbo, Inc. v. Oakley, Inc. (N.D. Cal.) (lead counsel for Oakley in litigation concerning goggles)
  • The Kingsford Charcoal Co. v. Creative Spark, IPR No. 2016-01831 (counsel for petitioner in proceeding challenging the patentability of a patent pertaining to charcoal briquets)
  • KAZ USA, Inc. v. Brita LP, IPR2016-01893 (counsel for patent owner in proceeding challenging the patentability of a patent pertaining to water filters)
  • 1-800-CONTACTS, d/b/a/ v. DITTO Technologies, Inc. (D. Utah) (lead counsel for plaintiff in litigation relating to systems for virtual display and modeling of eyewear)
  • Naraka Intellectual Property LLC v. Atlassian, Inc. (M.D. Pa.) (lead counsel for defendant in litigation relating to videoconferencing systems)
  • Ivoclar AG v. Glidewell Laboratories, (D. N.J.) (counsel for Ivoclar in litigation pertaining to lithium-silicate dental prostheses)
  • Intellectual Ventures v. Ericsson (Fed. Cir.) (appellate counsel for patent owner in appeal from an inter partes review relating to wireless communications systems)
  • Butamax Advanced Biofuels LLC v. Gevo, Inc., IPR 2013-00214, IPR 2013-00215 (counsel for petitioner in proceeding challenging the patentability of certain biofuel manufacturing patents)
  • Automated Tracking Solutions, LLC v. Awarepoint Corp., (E.D. Va.); Automated Tracking Solutions, LLC v. Teletracking Technologies, Inc. et al. (E.D. Va.) (counsel for patentee in multi-case litigation relating to radio frequency identification (RFID) technology)

Thought Leadership

Contact Information

Phone Number


William and Mary Law School
Political Science
The George Washington University


District of Columbia
U.S. District Court for the District of Maryland


  • U.S. District Court for the District of Delaware