Chelsea A. Loughran

Chelsea A. Loughran

Shareholder | Litigation
617.646.8429 LinkedIn Profile


  • BS, Biology, Brown University
  • MPH, Tufts University School of Medicine
  • JD, Northeastern University School of Law

Key Technologies

  • Biotechnology
  • Pharmaceuticals
  • Medical Devices

Practice Groups

Admitted to Practice

  • Massachusetts


Chelsea Loughran is a trial attorney and post-grant practitioner focusing on complex patent litigation and post-grant matters, including interferences. She focuses on patent litigation and post-grant matters in the biotechnology, pharmaceutical, and medical device fields. Chelsea has experience litigating cases in federal district courts across the country as well as the United States International Trade Commission (ITC) and the Patent Trial and Appeal Board (PTAB).

Most recently she served as lead trial counsel for Dyax Corporation (a subsidiary of Takeda Pharmaceutical Company) in a complex breach of contract and royalty dispute relating to antibody phage display technology, pending in the United States District Court for the District of Delaware.

Chelsea’s deep knowledge of the law and background and experience in life sciences technologies, in particular, has allowed her to effectively counsel a wide range of life sciences clients at various stages of development in protecting their most critical inventions as well as in defending against various intellectual property enforcement proceedings.

During law school, Chelsea interned for the Honorable Margaret Hinkle in Suffolk Superior Court. She also interned with the Office of General Counsel at Partner’s HealthCare System, where she assisted with drafting IP licensing agreements and developing hospital research conflict of interest policies.

Chelsea was awarded funding by the Northeastern University Alumni Association to do a co-operative internship at the AIDS Law Project in Johannesburg, South Africa, where she completed legal and public health research on access to essential medicines as well as the development of South African national infection control guidelines.

While completing her Masters at Tufts University, Chelsea did research for the Institute of Technology Assessment at Massachusetts General Hospital, looking at the behavioral effects of policy changes in the US Organ Procurement and Transplant Network.


Chelsea represents the firm’s clients in complex biotechnology and life sciences patent and contract disputes in district courts around the country. For example:

  • Currently representing, as lead trial counsel, Dyax Corporation in royalty and contract dispute relating to antibody phage display technology. First-chaired week-long bench trial before visiting Federal Circuit judge in District of Delaware.
  • Currently representing single-cell sequencing company in multi-patent competitor dispute now pending in the District of Delaware.
  • Served as day-to-day managing shareholder in successful interference proceeding before PTAB on behalf of client Precision Biosciences involving CAR-T cell therapies.
  • Represented Tai Diagnostics, Inc. in patent infringement suit brought in District of Delaware.
  • Played an integral role in the strategic development, prior art searching, and petition drafting of multiple inter partes review petitions against patents covering biologic therapies for chronic disease and patents directed to medical devices and medical device packaging.
  • Served as the primary drafter of over a dozen substantive and procedural motions filed for client Dyax Corporation over the course in a successful interference proceeding relating to patents covering yeast cell antibody display technology.
  • Served as lead associate representing The Jackson Laboratory in patent litigation on transgenic mice. Chelsea provided the Court with a Markman technology tutorial on relevant concepts in immunology, genetics and mouse nomenclature. She then successfully argued claim construction for one of the patents-in-suit, securing Jackson’s requested constructions on key disputed claim terms. Subsequently, in May 2010, Chelsea argued and won Jackson’s summary judgment motion, obtaining a ruling from the Court that Jackson does not infringe the plaintiff’s patent.

Chelsea also represents clients in the biotechnology and technology sectors in high-stakes patent cases before the International Trade Commission. For example:

  • Investigation No. 1012: Successfully represented Sony in complex multi-patent ITC investigation brought by Fujifilm related to magnetic data storage tapes and cartridges. Served as lead counsel on two patents: secured favorable decision of invalidity of both patents from ALJ and Commission; was also responsible for two corresponding inter partes review proceedings on behalf of Sony and successfully argued for and secured favorable final written decisions in both.
  • Investigation No. 935: Served as Lead Associate in International Trade Commission investigation relating to personal transporter devices in which she helped client secure a rare General Exclusion Order preventing the import of a wide range of infringing transporters.
  • Investigation No. 903: Successfully represented patent owner BTG, as plaintiffs in ITC investigation against multiple competitors concerning antibody pharmaceutical products against competitors targeting soon-to-be launched products. Served as Lead Associate during ten-month litigation and managed e-discovery, drafted multiple summary judgment and claim construction briefs, participated in oral argument at the Markman hearing, took and defended over a dozen fact and expert depositions and worked closely with client’s clinical expert to analyze clinical data and regulatory documents.

Chelsea also maintains an ongoing docket of pro bono cases and pro bono program development initiatives.

  • Represented mother of four and domestic violence victim in securing divorce, alimony, and child custody agreement on favorable terms.
  • Successfully represented (through trial and post-trial motions) a terminally ill victim of domestic violence in securing a divorce and favorable division of marital assets for estate planning purposes.
  • Successfully represented over a dozen pro bono clients referred from the Volunteer Lawyers Project of the Boston Bar Association in securing favorable decisions in their unemployment compensation appeals.
  • Created and launched a Greater Boston Patent Pro Bono Program as collaborative effort between Boston Intellectual Property Law Association and the Volunteer Lawyers for the Arts.
  • Collaborated with the MA ACLU on investigation into potential First Amendment violation.


  • Greater Boston Legal Services, Board Member and Member of Executive Committee
  • Women’s Bar Association and Women’s Bar Foundation, Member and Volunteer Attorney
  • Federal Circuit Bar Association, Member
  • Public Services Committee, Wolf Greenfield & Sacks, Chair
  • Diversity Committee, Wolf Greenfield & Sacks, Member


  • Repeatedly named to The Best Lawyers in America®
  • Named to the Massachusetts Super Lawyers list in 2023
  • Recognized as a “Top Women of Law” by Massachusetts Lawyers Weekly in 2018
  • Recognized for “Excellence in Pro Bono” by Massachusetts Lawyers Weekly in 2015 
  • Named 2014, 2015 Rising Star (list of 40 outstanding lawyers in the Boston area, age 40 or younger) by The National Law Journal
  • Awarded the Volunteer Attorney Award for Winter 2013 by the Women’s Bar Foundation’s Family Law Project
  • Named an “Up and Coming Lawyer” for 2013 by Massachusetts Lawyers Weekly 
  • Named one of Massachusetts Super Lawyers’ top 100 Women Attorneys
  • Named one of four finalists named to IP Magazine’s 2011 Young IP Lawyer of the Year Award
  • Named to the list of Massachusetts Rising Stars by Super Lawyers from 2011-2022


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Chelsea was a contributing researcher for the Public Health Advocacy Institute’s publication, A Guide for Plaintiffs’ Attorneys: Using Findings and Resources from USA v. Philip Morris USA Inc., et al. in Future Claims Against Big Tobacco.

While at Brown University, Chelsea was a member of the 2002 ECAC Championship Women’s Ice Hockey Team.