Image: Preston K. Ratliff II

Preston K. Ratliff II

Partner, Litigation Department

New York

Phone: 1(212) 318-6055
Fax: 1(212) 230-7742


Preston K. Ratliff II is the Chair of the Firm’s Litigation practice in New York. Mr. Ratliff focuses his practice on complex, high-stakes litigation with an emphasis on patent litigation in the biotechnology, pharmaceutical, chemical, agricultural, and renewable fuel sectors. He has successfully represented major and emerging companies both pre-trial and at trial.  Chambers USA notes that Mr. Ratliff is “really outstanding and excels at all aspects of litigation. What stands out is that he is a brilliant strategist who sees the big picture and can anticipate risks that aren’t always necessarily apparent…he is a very calming and unflappable presence even in the most difficult and stressful situations.” 

Mr. Ratliff also has extensive experience counseling clients with respect to their IP portfolios and evaluating strategic licensing opportunities.  In addition, Mr. Ratliff is a frequent publisher in patent journals and an invited speaker at some of the most prestigious life sciences industry conferences.


  • Chambers USA, Intellectual Property: Patent (2022-2023)
  • IAM Patent 1000, Leading Patent Practitioner (2015-2023)
  • In addition, IAM noted that he “has prevailed at trial for major companies in hard-fought battles”; as testament to his leadership qualities and outstanding legal dexterity, he assumed the chairmanship of the New York Litigation practice.
  • LMG Life Sciences, Life Sciences Star. (2018-2022)
  • Managing Intellectual Property, IP Stars. (2019-2023)
  • Topped Law360’s “Legal Lions” list for his Federal Circuit victory securing patent exclusivity against multiple defendants concerning Sunovion’s billion-dollar blockbuster schizophrenia and bipolar drug, Latuda®
  • Selected as one IAM Strategy 300’s “World’s Leading IP Strategists”
  • Named a “Minority Powerbroker” by Law360
  • Named one of Law360’s five “Rising Stars” for Intellectual Property


  • American University Washington College of Law, J.D. (1999)
  • Syracuse University, B.S. in Chemical Engineering and minor in German Language (1996)


  • Seagen Inc. v. Daiichi Sankyo Company Limited.
    Lead counsel in a hotly-contested, multi-billion dollar breach of contract intellectual property biotechnology dispute involving antibody-drug conjugates (“ADCs”) for the treatment of various cancers. Mr. Ratliff, along with his team, obtained a complete victory dismissing the opposition’s claims as both substantively meritless and time-barred. This win was reported to be among the largest disputes ever handled by the International Centre for Dispute Resolution, which is the American Arbitration Association’s forum for global conflict resolution.
  • Sumitomo Dainippon Pharma et al. v. Emcure Pharmaceuticals et al.
    Lead counsel that locked in full patent protection and revenues arising from Sumitomo Dainippon Pharma’s chemical compound patent for its billion-dollar-plus-per-year schizophrenia and bipolar drug, Latuda®. Specifically, Mr. Ratliff obtained a Federal Circuit decision that affirmed a district court’s November 2016 claim construction ruling and a February 2017 judgment of infringement against three generic drug manufacturers. Taken together, these dual victories secured patent protection for Latuda® while blocking more than a dozen generic drug manufacturers, including industry giant Teva Pharmaceuticals, from launching competing products.
  • Merck Sharp & Dohme Corp. v. Sandoz Inc. and Accord Healthcare, Inc.
    Co-led a trial team that won an important trial victory for Merck concerning its pharmaceutical product Emend® for Injection, which is used in the prevention of nausea and vomiting associated with cancer chemotherapy. After a bench trial, the district court ruled that Merck’s patent was valid and infringed, defeating the challenge brought by several generic companies. Mr. Ratliff also co-led a team that convinced the Patent Office to deny Canadian pharmaceutical company Apotex’s petition for an IPR, challenging a patent protecting Merck’s Emend® for Injection franchise. Mr. Ratliff also convinced the PTAB to deny Apotex’s further request to rehear its IPR petition.
  • Pfizer Inc. v. Amgen Fremont Inc. and Amgen Inc.
    Co-led a team that obtained a complete victory in a highly-complex breach of contract and intellectual property dispute in Delaware Chancery Court concerning billion-dollar biotechnology drug products.
  • Sucampo Pharmaceuticals Inc. et al. v. Par Pharmaceuticals, Inc. et al.
    Lead trial counsel for Sucampo in a Hatch-Waxman litigation protecting its leading medication Amitiza® for bowel disorders. In its suit against Par, Mr. Ratliff helped secure a settlement that provides Sucampo additional market exclusivity, as well as a royalty-bearing
  • Biovail International Laboratories v. Andrx Pharmaceuticals, LLC et al.
    Co-led a trial team that secured a highly-favorable settlement in a patent infringement litigation regarding the company’s top-selling drug product for managing blood pressure.




    • Intellectual Property Owners Association
    • New Jersey Intellectual Property Law Association
    • Metropolitan Black Bar Association
    • Admitted to practice in various courts throughout the United States, including the United States Court of Appeals for the Federal Circuit
    • Registered to practice before the United States Patent and Trademark Office

    Practice Areas


    Patent Office

    Patent Litigation

    Intellectual Property

    Life Sciences and Healthcare

    Global Dispute Resolution Practice for Japanese Clients




    United States Patent & Trademark Office

    New York Bar


    American University Washington College of Law, J.D. 1999

    Syracuse University, B.S. 1996

    Get In Touch With Us

    Contact Us