Jessamyn S. Berniker

Jessamyn Berniker Photo

Jessamyn Berniker is Co-Chair of the firm’s Patent Litigation practice. She has nearly two decades of experience focused on patent litigation and licensing disputes in the pharmaceutical, biotechnology, electronic, mechanical, digital media, and medical device industries. Jessamyn has served as counsel to companies such as AstraZeneca, Pfizer, Merck, Takeda, Roche, Novartis, and Bayer. 

The National Law Journal has selected Jessamyn as one of the 40 “most accomplished young attorneys in the D.C. area.”  She has been recognized in the 2018-2024 editions of IAM Patent 1000, the World’s Leading Patent Practitioners.  The 2018 edition praises her as a “biotech star” who “can carry the day in other types of disputes too.” Benchmark Litigation named Jessamyn to its 2017-2019 “Under 40 Hot List.” Managing Intellectual Property has recognized Jessamyn as one of the global “IP STARS - Top 250 Women in IP” from 2013 to 2017, and since 2018, the publication has recognized her as an "IP Star." LMG Life Sciences recognized Jessamyn as a “Life Science Star” in the area of patent litigation from 2012 to 2023.

Jessamyn served as the Co-Chair of the Pharma Litigation subcommittee for the ABA Intellectual Property Law Patent Litigation Committee for a number of years.  

Jessamyn serves on the advisory board of the Center for WorkLife Law at the UC Hastings College of Law, a research and advocacy organization that seeks to advance gender and racial equity in the workplace and in higher education. 

After law school, Jessamyn was a law clerk to Judge Arthur J. Gajarsa of the Court of Appeals for the Federal Circuit. She joined Williams & Connolly in 2002. She has argued before the Federal Circuit, has participated in thirteen district court trials and arbitration hearings, and has appeared several times before the PTAB. 

Jessamyn earned her B.S. in chemistry, magna cum laude, from Pacific Lutheran University in 1998, and her J.D., cum laude, from Harvard Law School. Prior to law school, she spent several months conducting organic chemistry research at Argonne National Laboratory.    Jessamyn is proficient in French.

A long-time singer, she has performed with Hugh Jackman and Demi Lovato.

Representative Experience

Though all cases vary and none is predictive, Jessamyn’s experience includes:

  • Served as lead counsel for AstraZeneca in litigation brought by Bristol-Myers Squibb in the District of Delaware relating to AstraZeneca’s cancer immunotherapy product Imfinzi®. 
  • Served as lead counsel for AstraZeneca in the District of Delaware in a Hatch-Waxman patent matter relating to the anti-cancer agent, Tagrisso®.    
  • Served as lead counsel on behalf of Ionis Pharmaceuticals in an arbitration against Alnylam concerning a Strategic Collaboration and License Agreement regarding antisense and RNAi technology.  The panel returned a victory for our client, awarding Ionis $41.2 million.
  • Served as lead counsel for Novartis in the District of Delaware in a Hatch-Waxman patent matter relating to the Xiidra®. 
  • Serving as counsel for a biopharmaceutical company in a confidential arbitration regarding the COVID-19 vaccine. 
  • Served as lead counsel for MedImmune in a case brought by UCB BioPharma. UCB sought damages from MedImmune, alleging that MedImmune’s Synagis® product infringed one of its patents. UCB elected to dismiss the case with prejudice.
  • Served as lead counsel for AstraZeneca and Nektar Therapeutics in district court and PTAB proceedings relating to AstraZeneca’s Movantik® product. Successfully obtained a ruling from the PTAB denying institution on all claims. 
  • Represented Petroleum GeoServices in IPR proceedings and at the Federal Circuit against WesternGeco successfully invalidating three patents relating to patents directed to seismic surveying technology. The asserted patents previously were the subject of a district court judgment of validity and damages of over $100,000,000 against Petroleum GeoServices’ supplier.   
  • Represented Pfizer in the District of Delaware in a Hatch-Waxman patent matter relating to the anti-cancer agent, Sutent®. 
  • Represented MedImmune in a dispute against PDL BioPharma in which MedImmune won summary judgment invalidating a key biotechnology patent (the “Queen patent”) held by PDL and further obtained a $92.5 million settlement from PDL.
  • Represented MedImmune in a dispute with Genentech where MedImmune sought to invalidate a Genentech patent (the “Cabilly patent”) relating to synthesis of genetically-engineered antibodies. The case settled prior to trial.  
  • Represented ACell in the Northern District of Indiana and the Federal Circuit regarding extracellular matrix technology used to repair and remodel damaged tissues and organs. ACell prevailed on all claims that were asserted against it.




"IP Star," Managing Intellectual Property, 2018-2024

"Intellectual Property (D.C.),” Chambers USA, 2024

"Leading Lawyer," in the category of Intellectual Property: Patents: Litigation, The Legal 500, 2023-2024

“Leading Patent Litigation Attorney,” IAM Patent 1000, 2018-2024

"Recommended - Individuals: Life Science Litigation," IAM Patent 1000, 2024

"IAM Global Leaders," IAM Patent 1000, 2024

“Life Science Star,” LMG Life Sciences, 2012-2023

“Litigation Star,” Benchmark Litigation, 2022-2024

“500 Leading Litigators in America,” Lawdragon, 2023-2024

“40 & Under Hot List”, Benchmark Litigation, 2017-2019

Client Service All-Star for Patent Litigation, BTI Consulting, 2018

“IP STARS - Top 250 Women in IP,” Managing IP, 2013-2017

“Washington, D.C. Rising Stars,” The National Law Journal, 2017


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