Mary C. Hennessey, Esq., is the General Counsel of the Patient-Centered Outcomes Research Institute (PCORI).  She advises the Board of Governors, the Executive Director and PCORI leaders on legal and strategic issues to advance PCORI’s mission-driven research agenda, programmatic initiatives and engagement with the public.  As the leader of the Office of the General Counsel, she manages PCORI’s legal affairs, including the legal framework for research and programmatic award commitments, corporate governance, and operations.

Prior to PCORI, Hennessey was legal counsel for the American Society of Clinical Oncology (ASCO), where she served as the primary attorney for ASCO’s affiliate, the Conquer Cancer Foundation, and as the compliance officer.  Hennessey also served as an attorney at the U.S. Food and Drug Administration in the Center for Drug Evaluation and Research, focusing on regulatory and enforcement matters relating to drug approval, development, manufacturing, marketing and distribution.  She also was an associate with the law firms of Ropes & Gray, LLP and Michaels, Wishner & Bonner in their healthcare practices, where she represented academic medical centers, hospitals, physician groups, insurers and managed care organizations on regulatory, corporate and governance matters. Hennessey served as a law clerk to The Honorable Thomas F. Hogan in the U.S. District Court for the District of Columbia.

Hennessey is a graduate of Harvard Law School and Harvard/Radcliffe College. She is a member of the bars of Maryland and the District of Columbia. She previously served as a member of the U.S. Department of Health and Human Services Advisory Council on Blood Stem Cell Transplantation.

Conflicts of Interest

As of June 1, 2023

Financial or Business Associations:

  • None reported.

Personal Associations:

  • Food and Drug Administration Alumni Association, Member, Self
  • American Health Lawyers Association, Member, Self 
  • Petrie-Flom Center Health Care General Counsel Roundtable, Participant, Self


Person Type