Jessamyn S. Berniker

Jessamyn Berniker Photo

Jessamyn Berniker’s practice focuses on patent litigation and licensing disputes.  She has handled patent litigation and licensing dispute matters in a wide variety of industries, including the pharmaceutical, biotechnology, electronic, mechanical, digital media, and medical device industries. In conjunction with her pharmaceutical practice, Jessamyn has served as counsel to companies such as AstraZeneca, Pfizer, Alcon (now part of Novartis), Takeda, and Bayer.  As part of her biotechnology practice, Jessamyn has served as counsel to companies such as MedImmune, Genentech and ACell.

The National Law Journal has named Jessamyn Berniker as one of the 40 “most accomplished young attorneys in the D.C. area.” The D.C. Rising Stars are the region’s 40 most promising lawyers under age 40 who have influence in their practice areas, demonstrated strong leadership qualities, developed unique practice niches, and showed expertise in litigation or transactional work.  She has been recognized in the 2018 edition 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 has named Jessamyn to its 2017 “Under 40 Hot List”, which honors the achievements of the nation’s most accomplished legal partners of the age of forty or younger. Managing Intellectual Property has recognized Jessamyn as one of the global “IP STARS - Top 250 Women in IP” from 2013 - 2017. LMG Life Sciences recognized Jessamyn as a “Life Science Star” in the area of patent litigation from 2012 to 2017. Jessamyn is the Co-Chair of the Pharma Litigation subcommittee for the ABA Intellectual Property Law Patent Litigation Committee for 2016-2017. She also served as Co-Chair of the subcommittee for 2015-2016.

Jessamyn is a former clerk at the U.S. Court of Appeals for the Federal Circuit. She has argued before the Federal Circuit and has participated in ten trials, including several patent matters.  She has significant litigation experience in criminal, copyright, antitrust, legal malpractice, and general civil matters as well. 

She regularly serves on the faculty of the ALI course Trial of a Patent Case.

Born in Los Angeles and raised in Washington State, Jessamyn received her B.S. in chemistry, magna cum laude, from Pacific Lutheran University in 1998, and her J.D., cum laude, from Harvard Law School.  During college and prior to law school she spent several months conducting organic chemistry research at Argonne National Laboratory just outside of Chicago.  After law school, Ms. Berniker was a law clerk to Judge Arthur J. Gajarsa of the Court of Appeals for the Federal Circuit.  She joined Williams & Connolly in 2002.  Jessamyn is proficient in French.

She is a long-time member of the 18th Street Singers, a Washington-based choir that performs regularly at the Kennedy Center.

Representative Experience

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

  • 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.
  • Represented Petroleum GeoServices in IPR proceedings and at the Federal Circuit against WesternGeco relating to patents directed to seismic surveying technology.  Argued successfully before the PTAB that three patents asserted by WesternGeco against Petroleum GeoServices were invalid.  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. Also obtained a Federal Circuit reversal from a PTAB decision invalidating a key PGS patent claim. 
  • Represents AstraZeneca in litigation brought by Bristol-Myers Squibb in the District of Delaware relating to AstraZeneca’s cancer immunotherapy product Imfinzi®.
  • Represented Pfizer in the District of Delaware in a Hatch-Waxman patent matter relating to the anti-cancer agent, Sutent®. Sutent® sells more than $1 billion worldwide annually. It is the most prescribed oral metastatic renal cell carcinoma (advanced kidney cancer) product in the United States. The District of Delaware Court ruled in Pfizer’s favor, and the Court of Appeals for the Federal Circuit affirmed the decision on appeal.
  • Represented Nektar Therapeutics and AstraZeneca in responding to a petition for Inter Partes Review filed by Neptune Generics relating to a patent concerning AstraZeneca’s Movantik® product.  Successfully obtained a ruling from the PTAB denying institution on all claims.
  • 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.



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

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

“40 & Under Hot List”, Benchmark Litigation, 2017-2018

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

"IP Star," Managing Intellectual Property, 2018

“Life Science Star,” LMG Life Sciences, 2012-2017

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


Government Service

Law Clerk, Judge Arthur J. Gajarsa, United States Court of Appeals for the Federal Circuit, 2001-2002

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