Dr. David Marsh focuses extensively on intellectual property counseling, patent prosecution, inter partes and ex parte matters, Hatch-Waxman issues, diligences and intellectual property aspects of transactions and other corporate matters, including in the artificial intelligence, biotechnology, business methods, chemical, clothing, computer media, consumer products, pharmaceutical, machine learning, material science and medical device areas. His experience includes:

  • Worldwide patent prosecution and patent office dispute experience.
  • Appeal counsel at the United States Patent and Trademark Office’s Patent Trial and Appeal Board.
  • Lead counsel for numerous post-allowance proceedings at the United States Patent and Trademark Office’s Patent Trial and Appeal Board.
  • Advises on international treaty intellectual property obligations including under the Biodiversity Convention and the General Agreement on Tariffs and Trade.

Dr. Marsh carried out his graduate work in molecular biology at Cambridge, England, and his post-doctoral work at Yale University. His research experience includes molecular biology, immunology, biochemistry, and mammalian and plant genetics. He has represented life science clients in a broad range of technologies including: immune-oncology, gene-editing, microbiome engineering, cell and gene therapy, small molecule, small RNAs and antibody therapies, bioenergy, medical devices, and agricultural breeding and engineering.


  • Lead patent procurement counsel for first-in-class pharmaceuticals. Patents have been successfully and repeatedly enforced.
  • Assist Bayer with the prosecution of patent portfolios critical for the protection of key DNA breakthroughs. The representation includes numerous appeal and multi-party opposition proceedings in the US and abroad.
  • Assist Bruin Biometrics with the prosecution of key patent portfolios for the protection of wound management products in the US and abroad.
  • Assist Finch Therapeutics with the prosecution of patent portfolios for the protection of microbiome products.


Life Sciences 2022 Guide (pdf)
Chambers and Partners
FDA Seeks to Deepen Engagement with USPTO on Pharmaceutical Patents
Life Sciences 2021 Guide (pdf)
Chambers and Partners
Life Sciences 2020 Guide (pdf)
Chambers and Partners


Chambers Global
Life Sciences: IP/Patent Litigation (United States) (2020)
Chambers USA
Intellectual Property: Patent Prosecution (DC) (2010-2023)
Life Sciences: IP/Patent Litigation (Nationwide) (2009-2019)
IAM Global Leaders
United States: DC Metro Area (2020-2022)


  • J.D., New York University School of Law, 1995
  • C.P.E., Nottingham Law School, 1992
  • Ph.D., Institute of Plant Science Research, 1989
  • B.Sc., University of London, 1985
  • District of Columbia
  • AIPLA Quarterly Journal - Editorial Board (2013-2016)

  • Editor, BioScience Law Review

  • Fellow, Royal Society for the Encouragement of Arts, Manufactures and Commerce


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