• LL.B., 1982
    McGill University
  • B.C.L., 1982
    McGill University
  • M.B.A., 1986
    Concordia University
  • Various courses, D.E.S.S., Drug Development, Faculty of Pharmacy
    University of Montréal

Year of Call/Admission

  • Québec, 1983

Languages Spoken

  • French
  • English

Marie Lafleur

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+1 514 397 7529
+1 514 397 7600 (fax)

Marie Lafleur is a senior partner and member of the Montréal office's Intellectual Property Litigation team. She regularly appears before the Federal Court of Canada and the provincial courts of the Province of Québec in litigation involving the infringement and the validity of patents, trademarks, copyrights and industrial designs as well as in matters concerning trade secrets and unfair competition. Her expertise extends to all extraordinary remedies, including seizures before judgement and injunctions and she is fully versed in all aspects of conflict resolution, as well as dispute resolution mechanisms.

More particularly, Ms. Lafleur is specialized in the litigation of pharmaceutical patents. She is lead counsel in NOC cases and has represented companies in numerous proceedings seeking to prohibit the Minister of Health Canada from issuing notices of compliance which would allow the sale of generic versions of patented drugs, such as citalopram, escitalopram, doxylamine/pyridoxine, cyclosporine, omeprazole, diltiazem, divalproex and terazosin, among others. She has been involved in judicial review applications dealing with the addition or the removal of patents from the patent register as well as in patent litigation concerning the infringement and the validity of pharmaceutical patents. 

Honours and Awards

  • Recognized by IAM Patent 1000 : Handling crucial proceedings for Duchesnay and LEO Pharma, Julie Desrosiers and Marie Lafleur “are really phenomenal, have a great work ethic and are creative in their approaches.” “Desrosiers has a deep understanding of our technology, which enables her to mount the best defences. Lafleur has spent many years serving the drug industry and knows it inside out.” (2015)
  • Recognized by the Who's Who Legal: Canada 2014 in the area of patents
  • Recognized by IAM Patent 1000 – The World’s Leading Patent Practitioners 2014 for Patent Litigation
  • The firm was named in the “2013 Canadian Impact Patent Cases of the Year” category for its work on the Apotex v Lundbeck case. Lundbeck was advised in these proceedings by a team that included Julie Desrosiers, Marie Lafleur, Christian Leblanc and Hilal El Ayoubi.
  • Recognized by IAM Patent 1000 – The World’s Leading Patent Practitioners 2013 for Patent Litigation
  • Recognized by IAM Patent 1000 – The World’s Leading Patent Practitioners 2012 for Patent Litigation
  • Recognized by IAM Life Science 250 – The World’s Leading Life Science Patent Litigators 2010


  • Member, Québec Bar
  • Member, Bar of Montréal
  • Member, Canadian Bar Association
  • Fellow Member, Intellectual Property Institute of Canada