Patrick O'Brien

Partner

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Contact

  • JD, Boston University School of Law, 1989
  • BA, University of Illinois, 1983

Qualifications

  • Massachusetts, 1989
  • New York, 2012
  • Legal 500, Finance (2015-2017)
  • IFLR1000: The Guide to the World’s Leading Financial Law Firms, Leading Lawyer (2013-2018)
  • The Best Lawyers in America (Securities and Capital Markets Law) (2006-2018)
  • Chambers USA: America's Leading Lawyers for Business (2008-2017)
  • International Who’s Who of Life Sciences (2014)
  • PLC Which Lawyer (2010-2011)

Patrick O'Brien

Partner

Patrick O’Brien is co-head of the firm’s securities and public companies practice. He concentrates his practice on representing companies and underwriters in financings as well as public and private companies in M&A transactions. Patrick has extensive experience representing healthcare, life sciences and technology companies and underwriters in connection with equity and debt offerings, as well as mergers and acquisitions. 

Experience

  • Representative clients include:
    • Quintiles IMS Holdings, Inc.
    • Alexion Pharmaceuticals, Inc.
    • Psivida, Inc.
  • Represented the following issuers in their proposed initial public offerings: IMS Health Holdings, Inc., Aptalis Holdings Inc., Par Pharmaceutical Holdings, Inc., Iasis Healthcare Corporation, and Petco Holdings, Inc. 
  • Represented the lead underwriters in initial public offerings and follow on offerings of:
    • Dimension Therapeutics, Inc.
    • Seres Therapeutics, Inc.
    • Proteon Therapeutics Inc.
    • Ocular Therapeutics, Inc.
    • Sage Therapeutics, Inc.
    • Zafgen, Inc.
    • Reylpsa, Inc. 
    • Karyopharm Therapeutics, Inc.
    • Foundation Medicine, Inc. 
    • bluebird bio, Inc. 
  • Represented Par Pharmaceutical Holdings, Inc. and Immucor, Inc. in high yield bond offerings. 
  • Represented Alexion Pharmaceuticals, Inc. in its $610 million acquisition (plus milestones) of Enobia Inc.
  • Represented a publicly traded specialty pharmaceutical company in a complex acquisition and related royalty based financing.
  • Represented a university in connection with the sale of a pharmaceutical royalty stream.

Publications