David Berl’s practice focuses on patent litigation, principally in the biotechnology, pharmaceutical, energy, and electronics fields.  David has served as lead counsel in Hatch-Waxman trials, in appellate proceedings in the Court of Appeals for the Federal Circuit, and in inter partes review proceedings before the PTO.  David regularly serves as lead counsel to major corporations in significant patent litigations and has tried numerous patent cases that have resulted in verdicts favorable to his clients.  

David was named a “Rising Star” in intellectual property by Law360 in 2015 and was selected as a leading patent litigation attorney in the 2014 to 2018 editions of IAM Patent 1000. He has been recognized as a “Life Science Star” by LMG Life Sciences from 2013 to 2018.

Raised in Denver, David received an undergraduate degree in biology from the Massachusetts Institute of Technology in 1997, and his J.D. from Stanford Law School, where he was a member of the Order of the Coif and lead articles editor for the Stanford Journal of Law, Business and Finance.  David spent a year as a litigation associate at Wilson Sonsini Goodrich & Rosati followed by a year clerking for Judge Alvin A. Schall of the U.S. Court of Appeals for the Federal Circuit.  He joined Williams & Connolly in 2002.

Representative Experience

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

  • Lead counsel for Bayer Healthcare in a Hatch-Waxman trial against Watson in the United States District Court for the District of Delaware, relating to Watson’s effort to market a generic version of Bayer Healthcare’s erectile dysfunction drug vardenafil.  The Court ruled from the bench in Bayer Healthcare’s favor, upholding the validity of Bayer Healthcare’s patents directed to vardenafil.
  • Represented Wyeth in connection with district court and inter partes review, and appellate proceedings regarding its antibiotic product Tygacil. In one of the first pharmaceutical inter partes review cases to proceed to trial and appeal, David argued successfully to the Patent Trial and Appeal Board that the claims of Wyeth’s patent were valid.  David also argued the case on appeal to the Court of Appeals for the Federal Circuit, which affirmed the Board’s finding of validity.
  • Lead counsel for Pfizer in a Hatch-Waxman trial against Actavis in the United States District Court for the District of Delaware.  The case involved a challenge by Actavis to Pfizer’s patent regarding its platform technology for avoiding the abuse of opioid drugs, embodied by its Embeda product.
  • Lead counsel for Bayer in the Federal Circuit and district court in a patent suit filed by Biogen relating to treatments for multiple sclerosis. The district court dismissed the claims against Bayer on the basis of an interpretation of the America Invents Act, and the Federal Circuit affirmed the dismissal.  David argued the case before the district court and the Federal Circuit.
  • Lead counsel for energy services company Petroleum GeoServices in inter partes review proceedings against Schlumberger subsidiary 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.
  • Co-Lead Counsel for MedImmune in its declaratory judgment action challenging the “Queen patents” assigned to PDL BioPharma, among the most widely licensed patent portfolios in the biotechnology industry.  David argued, and the court ruled on summary judgment, that the asserted Queen patent was invalid as anticipated.
  • Lead counsel for Bayer Animal Health in patent litigation and associated litigation against FDA regarding a generic version of its Baytril product. David argued successfully that the Agency’s approval of a generic version of Baytril was unlawful, and in a rare order, the district court ordered FDA to withdraw approval of the generic product.



“Future Star,” Benchmark Litigation, 2016-2019

“Leading Patent Litigation Attorney,” IAM Patent 1000, 2014-2018

“Life Science Star,” LMG Life Sciences, 2013-2018

"Under 40 Hot List," Benchmark Litigation, 2016

“Rising Star in Intellectual Property,” Law360, 2015


Government Service

Law Clerk, Judge Alvin A. Schall, United States Court of Appeals for the Federal Circuit, 2001-2002

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